Mark Nicolls

All Publications

• CT strain metrics allow for earlier diagnosis of bronchiolitis obliterans syndrome after hematopoietic cell transplant. Blood advances Sharifi, H., Bertini, C. D., Alkhunaizi, M., Hernandez, M. P., Musa, Z., Borges, C., Turk, I., Bashoura, L., Dickey, B. F., Cheng, G. S., Yanik, G. A., Galban, C., Guo, H. H., Godoy, M., Reinhardt, J., Hoffman, E., Castro, M., Rondon, G., Alousi, A., Champlin, R. E., Shpall, E. J., Lu, Y., Peterson, S. W., Datta, K., Nicolls, M., Hsu, J. L., Sheshadri, A. 2024

  Abstract

  Bronchiolitis obliterans syndrome (BOS) after hematopoietic cell transplantation (HCT) is associated with substantial morbidity and mortality. Quantitative CT (qCT) can help diagnose advanced BOS meeting National Institutes of Health (NIH) criteria (NIH-BOS) but has not been used to diagnose early, often asymptomatic BOS (early BOS), limiting the potential for early intervention and improved outcomes. Using Pulmonary Function Tests (PFT) to define NIH-BOS, early BOS, and mixed BOS (NIH-BOS with restrictive lung disease) in patients from two large cancer centers, we applied qCT to identify early BOS and distinguish between types of BOS. Patients with transient impairment or healthy lungs were included for comparison. PFT were done at month 0, 6, and 12. Analysis was performed with association statistics, principal component analysis, conditional inference trees (CIT), and machine learning (ML) classifier models. Our cohort included 84 allogeneic HCT recipients -- 66 BOS (NIH-defined, early, or mixed) and 18 without BOS. All qCT metrics had moderate correlation with Forced Expiratory Volume in 1 second, and each qCT metric differentiated BOS from those without BOS (non-BOS) (P < 0.0001). CIT's distinguished 94% of participants with BOS versus non-BOS, 85% early BOS versus non-BOS, 92% early BOS versus NIH-BOS. ML models diagnosed BOS with area under the curve (AUC) 0.84 (95% confidence interval [CI] 0.74-0.94) and early BOS with AUC 0.84 (95% CI 0.69 - 0.97). Quantitative CT metrics can identify individuals with early BOS, paving the way for closer monitoring and earlier treatment in this vulnerable population.

  View details for DOI 10.1182/bloodadvances.2024013748

  View details for PubMedID 39163616

• 3D Imaging Reveals Complex Microvascular Remodeling in the Right Ventricle in Pulmonary Hypertension. Circulation research Ichimura, K., Boehm, M., Andruska, A. M., Zhang, F., Schimmel, K., Bonham, S., Kabiri, A., Kheyfets, V. O., Ichimura, S., Reddy, S., Mao, Y., Zhang, T., Wang, G., Santana, E. J., Tian, X., Essafri, I., Vinh, R., Tian, W., Nicolls, M. R., Yajima, S., Shudo, Y., MacArthur, J. W., Woo, Y. J., Metzger, R. J., Spiekerkoetter, E. 2024

  Abstract

  Pathogenic concepts of right ventricular (RV) failure in pulmonary arterial hypertension focus on a critical loss of microvasculature. However, the methods underpinning prior studies did not take into account the 3-dimensional (3D) aspects of cardiac tissue, making accurate quantification difficult. We applied deep-tissue imaging to the pressure-overloaded RV to uncover the 3D properties of the microvascular network and determine whether deficient microvascular adaptation contributes to RV failure.Heart sections measuring 250-µm-thick were obtained from mice after pulmonary artery banding (PAB) or debanding PAB surgery and properties of the RV microvascular network were assessed using 3D imaging and quantification. Human heart tissues harvested at the time of transplantation from pulmonary arterial hypertension cases were compared with tissues from control cases with normal RV function.Longitudinal 3D assessment of PAB mouse hearts uncovered complex microvascular remodeling characterized by tortuous, shorter, thicker, highly branched vessels, and overall preserved microvascular density. This remodeling process was reversible in debanding PAB mice in which the RV function recovers over time. The remodeled microvasculature tightly wrapped around the hypertrophied cardiomyocytes to maintain a stable contact surface to cardiomyocytes as an adaptation to RV pressure overload, even in end-stage RV failure. However, microvasculature-cardiomyocyte contact was impaired in areas with interstitial fibrosis where cardiomyocytes displayed signs of hypoxia. Similar to PAB animals, microvascular density in the RV was preserved in patients with end-stage pulmonary arterial hypertension, and microvascular architectural changes appeared to vary by etiology, with patients with pulmonary veno-occlusive disease displaying a lack of microvascular complexity with uniformly short segments.3D deep tissue imaging of the failing RV in PAB mice, pulmonary hypertension rats, and patients with pulmonary arterial hypertension reveals complex microvascular changes to preserve the microvascular density and maintain a stable microvascular-cardiomyocyte contact. Our studies provide a novel framework to understand microvascular adaptation in the pressure-overloaded RV that focuses on cell-cell interaction and goes beyond the concept of capillary rarefaction.

  View details for DOI 10.1161/CIRCRESAHA.123.323546

  View details for PubMedID 38770652

• Ultrasound Neuromodulation of an Anti-Inflammatory Pathway at the Spleen Improves Experimental Pulmonary Hypertension. Circulation research Zafeiropoulos, S., Ahmed, U., Bekiaridou, A., Jayaprakash, N., Mughrabi, I. T., Saleknezhad, N., Chadwick, C., Daytz, A., Kurata-Sato, I., Atish-Fregoso, Y., Carroll, K., Al-Abed, Y., Fudim, M., Puleo, C., Giannakoulas, G., Nicolls, M., Diamond, B., Zanos, S. 2024

  Abstract

  Inflammation is pathogenically implicated in pulmonary arterial hypertension; however, it has not been adequately targeted therapeutically. We investigated whether neuromodulation of an anti-inflammatory neuroimmune pathway involving the splenic nerve using noninvasive, focused ultrasound stimulation of the spleen (sFUS) can improve experimental pulmonary hypertension.Pulmonary hypertension was induced in rats either by Sugen 5416 (20 mg/kg SQ) injection, followed by 21 (or 35) days of hypoxia (sugen/hypoxia model), or by monocrotaline (60 mg/kg IP) injection (monocrotaline model). Animals were randomized to receive either 12-minute-long sessions of sFUS daily or sham stimulation for 14 days. Catheterizations, echocardiography, indices of autonomic function, lung and heart histology and immunohistochemistry, spleen flow cytometry, and lung single-cell RNA sequencing were performed after treatment to assess the effects of sFUS.Splenic denervation right before induction of pulmonary hypertension results in a more severe disease phenotype. In both sugen/hypoxia and monocrotaline models, sFUS treatment reduces right ventricular systolic pressure by 25% to 30% compared with sham treatment, without affecting systemic pressure, and improves right ventricular function and autonomic indices. sFUS reduces wall thickness, apoptosis, and proliferation in small pulmonary arterioles, suppresses CD3+ and CD68+ cell infiltration in lungs and right ventricular fibrosis and hypertrophy and lowers BNP (brain natriuretic peptide). Beneficial effects persist for weeks after sFUS discontinuation and are more robust with early and longer treatment. Splenic denervation abolishes sFUS therapeutic benefits. sFUS partially normalizes CD68+ and CD8+ T-cell counts in the spleen and downregulates several inflammatory genes and pathways in nonclassical and classical monocytes and macrophages in the lung. Differentially expressed genes in those cell types are significantly enriched for human pulmonary arterial hypertension-associated genes.sFUS causes dose-dependent, sustained improvement of hemodynamic, autonomic, laboratory, and pathological manifestations in 2 models of experimental pulmonary hypertension. Mechanistically, sFUS normalizes immune cell populations in the spleen and downregulates inflammatory genes and pathways in the lung, many of which are relevant in human disease.

  View details for DOI 10.1161/CIRCRESAHA.123.323679

  View details for PubMedID 38712557

• VIEWING PULMONARY HYPERTENSION THROUGH A PEDIATRIC LENS. The European respiratory journal Agarwal, S., Fineman, J., Cornfield, D. N., Alvira, C. M., Zamanian, R. T., Goss, K., Yuan, K., Bonnet, S., Boucherat, O., Pullamsetti, S., Alcázar, M. A., Goncharova, E., Kudryashova, T. V., Nicolls, M. R., de Jesús Pérez, V. 2024

  View details for DOI 10.1183/13993003.01518-2023

  View details for PubMedID 38575157

• B cells in pulmonary arterial hypertension: friend, foe or bystander? The European respiratory journal Sanges, S., Tian, W., Dubucquoi, S., Chang, J. L., Collet, A., Launay, D., Nicolls, M. R. 2024

  Abstract

  There is an unmet need for new therapeutic strategies that target alternative pathways to improve the prognosis of patients with pulmonary arterial hypertension (PAH). As immunity has been involved in the development and progression of vascular lesions in PAH, we review the potential contribution of B cells in its pathogenesis and evaluate the relevance of B cell-targeted therapies. Circulating B cell homeostasis is altered in PAH patients, with total B-cell lymphopenia, abnormal subset distribution (expansion of naive and antibody-secreting cells, reduction of memory B cells) and chronic activation. B cells are recruited to the lungs through local chemokine secretion, and activated by several mechanisms: 1) interaction with lung vascular auto-antigens through cognate B cell receptors; 2) co-stimulatory signals provided by T follicular helper (Tfh) cells (IL-21), T helper 2 (Th2) cells and mast cells (IL-4, IL-6 and IL-13); and 3) increased survival signals provided by B cell activating factor (BAFF) pathways. This activity results in the formation of germinal centres within perivascular tertiary lymphoid organs and in the local production of pathogenic autoantibodies that target the pulmonary vasculature and vascular stabilization factors (including angiotensin-II/endothelin-1 receptors and bone morphogenetic protein receptors). B cells also mediate their effects through enhanced production of pro-inflammatory cytokines, reduced anti-inflammatory properties by regulatory B cells, IgG-induced complement activation, and IgE-induced mast cell activation. Precision-medicine approaches targeting B cell immunity are a promising direction for select PAH conditions, as suggested by the efficacy of anti-CD20 therapy in experimental models and a trial of rituximab in systemic sclerosis-associated PAH.

  View details for DOI 10.1183/13993003.01949-2023

  View details for PubMedID 38485150

• Rat microbial biogeography and age-dependent lactic acid bacteria in healthy lungs. Lab animal Zhao, L., Cunningham, C. M., Andruska, A. M., Schimmel, K., Ali, M. K., Kim, D., Gu, S., Chang, J. L., Spiekerkoetter, E., Nicolls, M. R. 2024; 53 (2): 43-55

  Abstract

  The laboratory rat emerges as a useful tool for studying the interaction between the host and its microbiome. To advance principles relevant to the human microbiome, we systematically investigated and defined the multitissue microbial biogeography of healthy Fischer 344 rats across their lifespan. Microbial community profiling data were extracted and integrated with host transcriptomic data from the Sequencing Quality Control consortium. Unsupervised machine learning, correlation, taxonomic diversity and abundance analyses were performed to determine and characterize the rat microbial biogeography and identify four intertissue microbial heterogeneity patterns (P1-P4). We found that the 11 body habitats harbored a greater diversity of microbes than previously suspected. Lactic acid bacteria (LAB) abundance progressively declined in lungs from breastfed newborn to adolescence/adult, and was below detectable levels in elderly rats. Bioinformatics analyses indicate that the abundance of LAB may be modulated by the lung-immune axis. The presence and levels of LAB in lungs were further evaluated by PCR in two validation datasets. The lung, testes, thymus, kidney, adrenal and muscle niches were found to have age-dependent alterations in microbial abundance. The 357 microbial signatures were positively correlated with host genes in cell proliferation (P1), DNA damage repair (P2) and DNA transcription (P3). Our study established a link between the metabolic properties of LAB with lung microbiota maturation and development. Breastfeeding and environmental exposure influence microbiome composition and host health and longevity. The inferred rat microbial biogeography and pattern-specific microbial signatures could be useful for microbiome therapeutic approaches to human health and life quality enhancement.

  View details for DOI 10.1038/s41684-023-01322-x

  View details for PubMedID 38297075

  View details for PubMedCentralID PMC10834367

• Pericytes contribute to pulmonary vascular remodeling via HIF2α signaling. EMBO reports Kim, H., Liu, Y., Kim, J., Kim, Y., Klouda, T., Fisch, S., Baek, S. H., Liu, T., Dahlberg, S., Hu, C. J., Tian, W., Jiang, X., Kosmas, K., Christou, H. A., Korman, B. D., Vargas, S. O., Wu, J. C., Stenmark, K. R., Perez, V. d., Nicolls, M. R., Raby, B. A., Yuan, K. 2024

  Abstract

  Vascular remodeling is the process of structural alteration and cell rearrangement of blood vessels in response to injury and is the cause of many of the world's most afflicted cardiovascular conditions, including pulmonary arterial hypertension (PAH). Many studies have focused on the effects of vascular endothelial cells and smooth muscle cells (SMCs) during vascular remodeling, but pericytes, an indispensable cell population residing largely in capillaries, are ignored in this maladaptive process. Here, we report that hypoxia-inducible factor 2α (HIF2α) expression is increased in the lung tissues of PAH patients, and HIF2α overexpressed pericytes result in greater contractility and an impaired endothelial-pericyte interaction. Using single-cell RNAseq and hypoxia-induced pulmonary hypertension (PH) models, we show that HIF2α is a major molecular regulator for the transformation of pericytes into SMC-like cells. Pericyte-selective HIF2α overexpression in mice exacerbates PH and right ventricular hypertrophy. Temporal cellular lineage tracing shows that HIF2α overexpressing reporter NG2+ cells (pericyte-selective) relocate from capillaries to arterioles and co-express SMA. This novel insight into the crucial role of NG2+ pericytes in pulmonary vascular remodeling via HIF2α signaling suggests a potential drug target for PH.

  View details for DOI 10.1038/s44319-023-00054-w

  View details for PubMedID 38243138

  View details for PubMedCentralID 9199463

• Single-Cell Imaging Maps Inflammatory Cell Subsets to Pulmonary Arterial Hypertension Vasculopathy. American journal of respiratory and critical care medicine Ferrian, S., Cao, A., McCaffrey, E. F., Saito, T., Greenwald, N. F., Nicolls, M. R., Bruce, T., Zamanian, R. T., Del Rosario, P., Rabinovitch, M., Angelo, M. 2023

  Abstract

  Rationale: Elucidating the immune landscape within and surrounding pulmonary arteries (PAs) is critical in understanding immune-driven vascular pathology in pulmonary arterial hypertension (PAH). Although more severe vascular pathology is often observed in hereditary (H)PAH patients with BMPR2 mutations, the involvement of specific immune cell subsets remains unclear. Methods: We used cutting-edge multiplexed ion beam imaging by time-of-flight (MIBI-TOF) to compare PAs and adjacent tissue in PAH lungs (idiopathic (I)PAH and HPAH) with unused donor lungs. Measurements: We quantified immune cells' proximity and abundance, focusing on those linked to vascular pathology, and evaluated their impact on pulmonary arterial smooth muscle cells (SMCs) and endothelial cells (ECs). Results: Distinct immune infiltration patterns emerged between PAH subtypes, with intramural involvement independently linked to PA occlusive changes. Notably, we identified monocyte-derived dendritic cells (mo-DCs) within PA subendothelial and adventitial regions, influencing vascular remodeling by promoting SMC proliferation and suppressing endothelial gene expression across PAH subtypes. In HPAH patients, pronounced immune dysregulation encircled PA walls, characterized by heightened perivascular inflammation involving TIM-3+ T cells. This correlated with an expanded DC subset expressing IDO-1, TIM-3, and SAMHD1, alongside increased neutrophils, SMCs, and α-SMA+ECs, reinforcing the severity of pulmonary vascular lesions. Conclusions: This study presents the first architectural map of PAH lungs, connecting immune subsets not only with specific PA lesions but also with heightened severity in HPAH compared to IPAH. Our findings emphasize the therapeutic potential of targeting mo-DCs, neutrophils, cellular interactions, and immune responses to alleviate severe vascular pathology in IPAH and HPAH.

  View details for DOI 10.1164/rccm.202209-1761OC

  View details for PubMedID 37934691

• Abnormal Lymphatic Sphingosine-1-Phosphate Signaling Aggravates Lymphatic Dysfunction and Tissue Inflammation. Circulation Kim, D., Tian, W., Wu, T. T., Xiang, M., Vinh, R., Chang, J. L., Gu, S., Lee, S., Zhu, Y., Guan, T., Schneider, E. C., Bao, E., Dixon, J. B., Kao, P., Pan, J., Rockson, S. G., Jiang, X., Nicolls, M. R. 2023

  Abstract

  Lymphedema is a global health problem with no effective drug treatment. Enhanced T-cell immunity and abnormal lymphatic endothelial cell (LEC) signaling are promising therapeutic targets for this condition. Sphingosine-1-phosphate (S1P) mediates a key signaling pathway required for normal LEC function, and altered S1P signaling in LECs could lead to lymphatic disease and pathogenic T-cell activation. Characterizing this biology is relevant for developing much needed therapies.Human and mouse lymphedema was studied. Lymphedema was induced in mice by surgically ligating the tail lymphatics. Lymphedematous dermal tissue was assessed for S1P signaling. To verify the role of altered S1P signaling effects in lymphatic cells, LEC-specific S1pr1-deficient (S1pr1LECKO) mice were generated. Disease progression was quantified by tail-volumetric and -histopathologic measurements over time. LECs from mice and humans, with S1P signaling inhibition, were then cocultured with CD4 T cells, followed by an analysis of CD4 T-cell activation and pathway signaling. Last, animals were treated with a monoclonal antibody specific to P-selectin to assess its efficacy in reducing lymphedema and T-cell activation.Human and experimental lymphedema tissues exhibited decreased LEC S1P signaling through S1P receptor 1 (S1PR1). LEC S1pr1 loss-of-function exacerbated lymphatic vascular insufficiency, tail swelling, and increased CD4 T-cell infiltration in mouse lymphedema. LECs, isolated from S1pr1LECKO mice and cocultured with CD4 T cells, resulted in augmented lymphocyte differentiation. Inhibiting S1PR1 signaling in human dermal LECs promoted T-helper type 1 and 2 (Th1 and Th2) cell differentiation through direct cell contact with lymphocytes. Human dermal LECs with dampened S1P signaling exhibited enhanced P-selectin, an important cell adhesion molecule expressed on activated vascular cells. In vitro, P-selectin blockade reduced the activation and differentiation of Th cells cocultured with shS1PR1-treated human dermal LECs. P-selectin-directed antibody treatment improved tail swelling and reduced Th1/Th2 immune responses in mouse lymphedema.This study suggests that reduction of the LEC S1P signaling aggravates lymphedema by enhancing LEC adhesion and amplifying pathogenic CD4 T-cell responses. P-selectin inhibitors are suggested as a possible treatment for this pervasive condition.

  View details for DOI 10.1161/CIRCULATIONAHA.123.064181

  View details for PubMedID 37609838

• Abnormal lymphatic S1P signaling aggravates lymphatic dysfunction and tissue inflammation. medRxiv : the preprint server for health sciences Kim, D., Tian, W., Wu, T. T., Xiang, M., Vinh, R., Chang, J., Gu, S., Lee, S., Zhu, Y., Guan, T., Schneider, E. C., Bao, E., Dixon, J. B., Kao, P., Pan, J., Rockson, S. G., Jiang, X., Nicolls, M. R. 2023

  Abstract

  BACKGROUND: Lymphedema is a global health problem with no effective drug treatment. Enhanced T cell immunity and abnormal lymphatic endothelial cell (LEC) signaling are promising therapeutic targets for this condition. Sphingosine-1-phosphate (S1P) mediates a key signaling pathway required for normal LEC function, and altered S1P signaling in LECs could lead to lymphatic disease and pathogenic T cell activation. Characterizing this biology is relevant for developing much-needed therapies.METHODS: Human and mouse lymphedema was studied. Lymphedema was induced in mice by surgically ligating the tail lymphatics. Lymphedematous dermal tissue was assessed for S1P signaling. To verify the role of altered S1P signaling effects in lymphatic cells, LEC-specific S1pr1 -deficient ( S1pr1 LECKO ) mice were generated. Disease progression was quantified by tail-volumetric and -histopathological measurements over time. LECs from mice and humans, with S1P signaling inhibition, were then co-cultured with CD4 T cells, followed by an analysis of CD4 T cell activation and pathway signaling. Finally, animals were treated with a monoclonal antibody specific to P-selectin to assess its efficacy in reducing lymphedema and T cell activation.RESULTS: Human and experimental lymphedema tissues exhibited decreased LEC S1P signaling through S1PR1. LEC S1pr1 loss-of-function exacerbated lymphatic vascular insufficiency, tail swelling, and increased CD4 T cell infiltration in mouse lymphedema. LECs, isolated from S1pr1 LECKO mice and co-cultured with CD4 T cells, resulted in augmented lymphocyte differentiation. Inhibiting S1PR1 signaling in human dermal LECs (HDLECs) promoted T helper type 1 and 2 (Th1 and Th2) cell differentiation through direct cell contact with lymphocytes. HDLECs with dampened S1P signaling exhibited enhanced P-selectin, an important cell adhesion molecule expressed on activated vascular cells. In vitro , P-selectin blockade reduced the activation and differentiation of Th cells co-cultured with sh S1PR1 -treated HDLECs. P-selectin-directed antibody treatment improved tail swelling and reduced Th1/Th2 immune responses in mouse lymphedema.CONCLUSION: This study suggests that reduction of the LEC S1P signaling aggravates lymphedema by enhancing LEC adhesion and amplifying pathogenic CD4 T cell responses. P-selectin inhibitors are suggested as a possible treatment for this pervasive condition.Clinical Perspective: What is New?: Lymphatic-specific S1pr1 deletion exacerbates lymphatic vessel malfunction and Th1/Th2 immune responses during lymphedema pathogenesis. S1pr1 -deficient LECs directly induce Th1/Th2 cell differentiation and decrease anti-inflammatory Treg populations. Peripheral dermal LECs affect CD4 T cell immune responses through direct cell contact.LEC P-selectin, regulated by S1PR1 signaling, affects CD4 T cell activation and differentiation.P-selectin blockade improves lymphedema tail swelling and decreases Th1/Th2 population in the diseased skin.What Are the Clinical Implications?: S1P/S1PR1 signaling in LECs regulates inflammation in lymphedema tissue.S1PR1 expression levels on LECs may be a useful biomarker for assessing predisposition to lymphatic disease, such as at-risk women undergoing mastectomyP-selectin Inhibitors may be effective for certain forms of lymphedema.

  View details for DOI 10.1101/2023.06.08.23291175

  View details for PubMedID 37398237

• A Selective Leukotriene B4 Antagonist, Acebilustat, for Treatment of Outpatients With COVID-19 Disease: A Randomized, Double-blind, Placebo-controlled Phase 2 Trial Levitt, J. E., Hedlin, H., Duong, S., Lu, D., Lee, J., Elkarra, N., Pinsky, B., Heffernan, E., Springman, E., Bonilla, H., Parsonnet, J., Zamanian, R. T., Langguth, J., Bollyky, J., Khosla, C., Nicolls, M. R., Desai, M., Moss, R., Rogers, A. AMER THORACIC SOC. 2023

  View details for Web of Science ID 000995814708319

• Using an Unsupervised Learning Ensemble to Identify and Evaluate PAH Immune Phenotypes Longitudinally During Disease Progression Sweatt, A., Hedlin, H. K., Haddad, F., Lawrie, A., Desai, M., Khatri, P., Nicolls, M. R., Rabinovitch, M., Zamanian, R. T. AMER THORACIC SOC. 2023

  View details for Web of Science ID 000995814702164

• Endotyping COPD: hypoxia-inducible factor-2 as a molecular "switch" between the vascular and airway phenotypes? European respiratory review : an official journal of the European Respiratory Society Myronenko, O., Foris, V., Crnkovic, S., Olschewski, A., Rocha, S., Nicolls, M. R., Olschewski, H. 2023; 32 (167)

  Abstract

  COPD is a heterogeneous disease with multiple clinical phenotypes. COPD endotypes can be determined by different expressions of hypoxia-inducible factors (HIFs), which, in combination with individual susceptibility and environmental factors, may cause predominant airway or vascular changes in the lung. The pulmonary vascular phenotype is relatively rare among COPD patients and characterised by out-of-proportion pulmonary hypertension (PH) and low diffusing capacity of the lung for carbon monoxide, but only mild-to-moderate airway obstruction. Its histologic feature, severe remodelling of the small pulmonary arteries, can be mediated by HIF-2 overexpression in experimental PH models. HIF-2 is not only involved in the vascular remodelling but also in the parenchyma destruction. Endothelial cells from human emphysema lungs express reduced HIF-2α levels, and the deletion of pulmonary endothelial Hif-2α leads to emphysema in mice. This means that both upregulation and downregulation of HIF-2 have adverse effects and that HIF-2 may represent a molecular "switch" between the development of the vascular and airway phenotypes in COPD. The mechanisms of HIF-2 dysregulation in the lung are only partly understood. HIF-2 levels may be controlled by NAD(P)H oxidases via iron- and redox-dependent mechanisms. A better understanding of these mechanisms may lead to the development of new therapeutic targets.

  View details for DOI 10.1183/16000617.0173-2022

  View details for PubMedID 36631133

• Evaluation of acebilustat, a selective inhibitor of leukotriene B4 biosynthesis, for treatment of outpatients with mild-moderate COVID-19 disease: A randomized, double-blind, placebo- controlled Phase 2 trial. Clinical infectious diseases : an official publication of the Infectious Diseases Society of America Levitt, J. E., Hedlin, H., Duong, S., Lu, D., Lee, J., Bunning, B., Elkarra, N., Pinsky, B. A., Heffernan, E., Springman, E., Moss, R. B., Bonilla, H. F., Parsonnet, J., Zamanian, R. T., Langguth, J. J., Bollyky, J., Khosla, C., Nicolls, M. R., Desai, M., Rogers, A. J. 2023

  Abstract

  The vast majority of COVID-19 disease occurs in outpatients where treatment is limited to anti-virals for high-risk subgroups. Acebilustat, a leukotriene B4 (LTB4) inhibitor, has potential to reduce inflammation and symptom duration.In a single-center trial spanning Delta and Omicron variants, outpatients were randomized to 100 mg of oral acebilustat or placebo for 28 days. Patients reported daily symptoms via electronic query through Day 28 with phone follow-up on Day 120 and collected nasal swabs on Days 1-10. The primary outcome was sustained symptom resolution to Day 28. Secondary 28-day outcomes included time to first symptom resolution, area under the curve (AUC) of longitudinal daily symptom scores; duration of viral shedding through Day 10; and symptoms on Day 120.Sixty participants were randomized to each study arm. At enrollment, median duration and number of symptoms were 4 (IQR 3-5) days and 9 (IQR 7-11) symptoms. Most patients (90%) were vaccinated with 73% having neutralizing antibodies. A minority (44%) of participants (35% in the acebilustat arm and 53% in placebo) had sustained symptom resolution at Day 28 (HR 0.6, 95% CI 0.34-1.04, p = 0.07 favoring placebo). There was no difference in mean AUC of symptom scores over 28 days (difference in mean of AUC 9.4, 95% CI -42.1-60.9, p=0.72). Acebilustat did not impact viral shedding or symptoms at Day 120.Sustained symptoms through Day 28 were common in this low-risk population. Despite this, LTB4 antagonism with acebilustat did not shorten symptom duration in outpatients with COVID-19.

  View details for DOI 10.1093/cid/ciad187

  View details for PubMedID 36996150

• A p53-TLR3 axis ameliorates pulmonary hypertension by inducing BMPR2 via IRF3. iScience Bhagwani, A. R., Ali, M., Piper, B., Liu, M., Hudson, J., Kelly, N., Bogamuwa, S., Yang, H., Londino, J. D., Bednash, J. S., Farkas, D., Mallampalli, R. K., Nicolls, M. R., Ryan, J. J., Thompson, A. A., Chan, S. Y., Gomez, D., Goncharova, E. A., Farkas, L. 2023; 26 (2): 105935

  Abstract

  Pulmonary arterial hypertension (PAH) features pathogenic and abnormal endothelial cells (ECs), and one potential origin is clonal selection. We studied the role of p53 and toll-like receptor 3 (TLR3) in clonal expansion and pulmonary hypertension (PH) via regulation of bone morphogenetic protein (BMPR2) signaling. ECs of PAH patients had reduced p53 expression. EC-specific p53 knockout exaggerated PH, and clonal expansion reduced p53 and TLR3 expression in rat lung CD117+ ECs. Reduced p53 degradation (Nutlin 3a) abolished clonal EC expansion, induced TLR3 and BMPR2, and ameliorated PH. Polyinosinic/polycytidylic acid [Poly(I:C)] increased BMPR2 signaling in ECs via enhanced binding of interferon regulatory factor-3 (IRF3) to the BMPR2 promoter and reduced PH in p53-/- mice but not in mice with impaired TLR3 downstream signaling. Our data show that a p53/TLR3/IRF3 axis regulates BMPR2 expression and signaling in ECs. This link can be exploited for therapy of PH.

  View details for DOI 10.1016/j.isci.2023.105935

  View details for PubMedID 36685041

• Decreasing ELK3 expression improves Bone Morphogenetic Protein Receptor 2 signaling and pulmonary vascular cell function in PAH. bioRxiv : the preprint server for biology Ali, M. K., Zhao, L., Perez, V. d., Nicolls, M. R., Spiekerkoetter, E. F. 2023

  Abstract

  ELK3 is upregulated in blood and pulmonary vascular cells of PAH patients and may play a significant role in PAH potentially through modulating BMPR2 signaling.

  View details for DOI 10.1101/2023.01.14.524023

  View details for PubMedID 36711443

  View details for PubMedCentralID PMC9882174

• PTPN1 Deficiency Modulates BMPR2 Signaling and Induces Endothelial Dysfunction in Pulmonary Arterial Hypertension. Cells Ali, M. K., Tian, X., Zhao, L., Schimmel, K., Rhodes, C. J., Wilkins, M. R., Nicolls, M. R., Spiekerkoetter, E. F. 2023; 12 (2)

  Abstract

  Bone morphogenic protein receptor 2 (BMPR2) expression and signaling are impaired in pulmonary arterial hypertension (PAH). How BMPR2 signaling is decreased in PAH is poorly understood. Protein tyrosine phosphatases (PTPs) play important roles in vascular remodeling in PAH. To identify whether PTPs modify BMPR2 signaling, we used a siRNA-mediated high-throughput screening of 22,124 murine genes in mouse myoblastoma reporter cells using ID1 expression as readout for BMPR2 signaling. We further experimentally validated the top hit, PTPN1 (PTP1B), in healthy human pulmonary arterial endothelial cells (PAECs) either silenced by siRNA or exposed to hypoxia and confirmed its relevance to PAH by measuring PTPN1 levels in blood and PAECs collected from PAH patients. We identified PTPN1 as a novel regulator of BMPR2 signaling in PAECs, which is downregulated in the blood of PAH patients, and documented that downregulation of PTPN1 is linked to endothelial dysfunction in PAECs. These findings point to a potential involvement for PTPN1 in PAH and will aid in our understanding of the molecular mechanisms involved in the disease.

  View details for DOI 10.3390/cells12020316

  View details for PubMedID 36672250

• The Human Respiratory Microbiome: Current Understandings and Future Directions. American journal of respiratory cell and molecular biology Zhao, L., Luo, J. L., Ali, M. K., Spiekerkoetter, E., Nicolls, M. R. 2022

  Abstract

  Microorganisms colonizing the human body. The lungs and respiratory tract, previously thought to be sterile, harbor diverse microbial communities and the genomes of bacteria (bacteriome), viruses (virome), and fungi (mycobiome). Recent advances in amplicon and shotgun metagenomic sequencing technologies, and data analyzing methods have greatly aided the identification and characterization of microbial populations from airways. The respiratory microbiome has been shown to play roles in human health and disease and is an area of rapidly emerging interest in pulmonary medicine. In this review we provide updated information in the field by focusing on four lung conditions including asthma, chronic obstructive pulmonary disease (COPD), cystic fibrosis (CF), and idiopathic pulmonary fibrosis (IPF). We evaluate gut, oral, and upper airway microbiomes, and how they contribute to lower airway flora. The discussion is followed by a systematic review of the lower airway microbiome in health and disease. We conclude with promising research avenues and implications for evolving therapeutics.

  View details for DOI 10.1165/rcmb.2022-0208TR

  View details for PubMedID 36476129

• Biochemical, biophysical, and immunological characterization of respiratory secretions in severe SARS-CoV-2 infections. JCI insight Kratochvil, M. J., Kaber, G., Demirdjian, S., Cai, P. C., Burgener, E. B., Nagy, N., Barlow, G. L., Popescu, M., Nicolls, M. R., Ozawa, M. G., Regula, D. P., Pacheco-Navarro, A. E., Yang, S., de Jesus Perez, V. A., Karmouty-Quintana, H., Peters, A. M., Zhao, B., Buja, M. L., Johnson, P. Y., Vernon, R. B., Wight, T. N., Stanford COVID-19 Biobank Study Group, Milla, C. E., Rogers, A. J., Spakowitz, A. J., Heilshorn, S. C., Bollyky, P. L. 2022; 7 (12)

  Abstract

  Thick, viscous respiratory secretions are a major pathogenic feature of COVID-19, but the composition and physical properties of these secretions are poorly understood. We characterized the composition and rheological properties (i.e., resistance to flow) of respiratory secretions collected from intubated COVID-19 patients. We found the percentages of solids and protein content were greatly elevated in COVID-19 compared with heathy control samples and closely resembled levels seen in cystic fibrosis, a genetic disease known for thick, tenacious respiratory secretions. DNA and hyaluronan (HA) were major components of respiratory secretions in COVID-19 and were likewise abundant in cadaveric lung tissues from these patients. COVID-19 secretions exhibited heterogeneous rheological behaviors, with thicker samples showing increased sensitivity to DNase and hyaluronidase treatment. In histologic sections from these same patients, we observed increased accumulation of HA and the hyaladherin versican but reduced tumor necrosis factor-stimulated gene-6 staining, consistent with the inflammatory nature of these secretions. Finally, we observed diminished type I interferon and enhanced inflammatory cytokines in these secretions. Overall, our studies indicated that increases in HA and DNA in COVID-19 respiratory secretion samples correlated with enhanced inflammatory burden and suggested that DNA and HA may be viable therapeutic targets in COVID-19 infection.

  View details for DOI 10.1172/jci.insight.152629

  View details for PubMedID 35730564

• Endogenous Retroviral Elements Generate Pathologic Neutrophils in Pulmonary Arterial Hypertension. American journal of respiratory and critical care medicine Taylor, S., Isobe, S., Cao, A., Contrepois, K., Benayoun, B. A., Jiang, L., Wang, L., Melemenidis, S., Ozen, M. O., Otsuki, S., Shinohara, T., Sweatt, A. J., Kaplan, J., Moonen, J., Marciano, D. P., Gu, M., Miyagawa, K., Hayes, B., Sierra, R. G., Kupitz, C. J., Del Rosario, P. A., Hsi, A., Thompson, A. A., Ariza, M. E., Demirci, U., Zamanian, R. T., Haddad, F., Nicolls, M. R., Snyder, M. P., Rabinovitch, M. 2022

  Abstract

  RATIONALE: The role of neutrophils and their extracellular vesicles (EVs) in the pathogenesis of pulmonary arterial hypertension is unclear.OBJECTIVES: Relate functional abnormalities in pulmonary arterial hypertension neutrophils and their EVs to mechanisms uncovered by proteomic and transcriptomic profiling.METHODS: Production of elastase, release of extracellular traps, adhesion and migration were assessed in neutrophils from pulmonary arterial hypertension patients and control subjects. Proteomic analyses were applied to explain functional perturbations, and transcriptomic data were used to find underlying mechanisms. CD66b-specific neutrophil EVs were isolated from plasma of patients with pulmonary arterial hypertension and we determined whether they produce pulmonary hypertension in mice.MEASUREMENTS AND MAIN RESULTS: Neutrophils from pulmonary arterial hypertension patients produce and release increased neutrophil elastase, associated with enhanced extracellular traps. They exhibit reduced migration and increased adhesion attributed to elevated beta1integrin and vinculin identified on proteomic analysis and previously linked to an antiviral response. This was substantiated by a transcriptomic interferon signature that we related to an increase in human endogenous retrovirus k envelope protein. Transfection of human endogenous retrovirus k envelope in a neutrophil cell line (HL-60) increases neutrophil elastase and interferon genes, whereas vinculin is increased by human endogenous retrovirus k dUTPase that is elevated in patient plasma. Neutrophil EVs from patient plasma contain increased neutrophil elastase and human endogenous retrovirus k envelope and induce pulmonary hypertension in mice, mitigated by elafin, an elastase inhibitor.CONCLUSIONS: Elevated human endogenous retroviral elements and elastase link a neutrophil innate immune response to pulmonary arterial hypertension.

  View details for DOI 10.1164/rccm.202102-0446OC

  View details for PubMedID 35696338

• The role of circular RNAs in pulmonary hypertension. The European respiratory journal Ali, M. K., Schimmel, K., Zhao, L., Chen, C. K., Dua, K., Nicolls, M. R., Spiekerkoetter, E. 2022

  Abstract

  Circular RNAs (CircRNAs) are endogenous, covalently circularized, non-protein-coding RNAs generated from back splicing. Most circRNAs are very stable, highly conserved, and expressed in a tissue-, cell- and developmental stage-specific manner. CircRNAs play a significant role in various biological processes, such as regulation of gene expression and protein translation via sponging of microRNAs and binding with RNA binding proteins. CircRNAs have become a topic of great interest in research due to their close link with the development of various diseases. Their high stability, conservation, and abundance in body fluids make them promising biomarkers for many diseases. A growing body of evidence suggests that aberrant expression of circRNAs and their targets plays a crucial role in pulmonary vascular remodeling and Group 1 pulmonary arterial hypertension (PAH) as well as other forms of pulmonary hypertension (PH) (Group 3 and 4). Here we discuss the roles and molecular mechanisms of circRNAs in the pathogenesis of pulmonary vascular remodeling and PH. We also highlight the therapeutic and biomarker potential of circRNAs in PH.

  View details for DOI 10.1183/13993003.00012-2022

  View details for PubMedID 35680145

• CES1 Deficiency Is Associated with Oxidative Stress Mediated Endoplasmic Reticulum/Mitochondrial Dysfunction in Pulmonary Endothelial Cells Agarwal, S. S., Chakraborty, A., Shamskhou, E., Condon, D. F., Suresh, K., Rabinovitch, M., Nicolls, M. R., Perez, V. AMER THORACIC SOC. 2022

  View details for Web of Science ID 000792480404639

• Overexpression of Pericyte HIF2 alpha Exacerbates Hypoxia Induced Pulmonary Hypertension and Right Ventricular Hypertrophy Kim, H., Liu, Y., Kim, J., Klouda, T., Hu, C., Tian, W., Jiang, X., Wu, J., Stenmark, K. R., Nicolls, M. R., De Jesus Perez, V., Raby, B. A., Yuan, K. AMER THORACIC SOC. 2022

  View details for Web of Science ID 000792480405285

• Divergent Roles of Lymphatic Endothelial Cell-Expressed Hypoxia-Inducible Factors in Airway Transplant Rejection Mcquiston, A. S., Kim, D., Vihn, R., Schneider, E. C., Tian, W., Jiang, X., Nicolls, M. R. AMER THORACIC SOC. 2022

  View details for Web of Science ID 000792480404141

• Single-Cell RNA-seq Reveals Transcriptionally Convergent Pulmonary Endothelial Cells in an Inflammatory Model of Pulmonary Arterial Hypertension with BMPR2 Dysfunction Kim, D., Zhao, L., Wu, T., Vihn, R., Schneider, E., Cunningham, C. M., Mcquiston, A. S., Kao, P. N., Jiang, X., Tian, A., Nicolls, M. R. AMER THORACIC SOC. 2022

  View details for Web of Science ID 000792480400176

• Biochemical, Biophysical, and Immunological Characterization of Respiratory Secretions in Severe SARS-CoV-2 (COVID-19) Infections. medRxiv : the preprint server for health sciences Kratochvil, M. J., Kaber, G., Demirdjian, S., Cai, P. C., Burgener, E. B., Nagy, N., Barlow, G. L., Popescu, M., Nicolls, M. R., Ozawa, M. G., Regula, D. P., Pacheco-Navarro, A. E., Yang, S., de Jesus Perez, V. A., Karmouty-Quintana, H., Peters, A. M., Zhao, B., Buja, M. L., Johnson, P. Y., Vernon, R. B., Wight, T. N., Stanford COVID-19 Biobank Study Group, Milla, C. E., Rogers, A. J., Spakowitz, A. J., Heilshorn, S. C., Bollyky, P. L. 2022

  Abstract

  Thick, viscous respiratory secretions are a major pathogenic feature of COVID-19 disease, but the composition and physical properties of these secretions are poorly understood. We characterized the composition and rheological properties (i.e. resistance to flow) of respiratory secretions collected from intubated COVID-19 patients. We find the percent solids and protein content are greatly elevated in COVID-19 compared to heathy control samples and closely resemble levels seen in cystic fibrosis, a genetic disease known for thick, tenacious respiratory secretions. DNA and hyaluronan (HA) are major components of respiratory secretions in COVID-19 and are likewise abundant in cadaveric lung tissues from these patients. COVID-19 secretions exhibit heterogeneous rheological behaviors with thicker samples showing increased sensitivity to DNase and hyaluronidase treatment. In histologic sections from these same patients, we observe increased accumulation of HA and the hyaladherin versican but reduced tumor necrosis factora"stimulated gene-6 (TSG6) staining, consistent with the inflammatory nature of these secretions. Finally, we observed diminished type I interferon and enhanced inflammatory cytokines in these secretions. Overall, our studies indicate that increases in HA and DNA in COVID-19 respiratory secretion samples correlate with enhanced inflammatory burden and suggest that DNA and HA may be viable therapeutic targets in COVID-19 infection.

  View details for DOI 10.1101/2022.03.28.22272848

  View details for PubMedID 35411348

• Exploring disease interrelationships in patients with lymphatic disorders: A single center retrospective experience. Clinical and translational medicine Rockson, S. G., Zhou, X., Zhao, L., Hosseini, D. K., Jiang, X., Sweatt, A. J., Kim, D., Tian, W., Snyder, M. P., Nicolls, M. R. 2022; 12 (4): e760

  Abstract

  The lymphatic contribution to the circulation is of paramount importance in regulating fluid homeostasis, immune cell trafficking/activation and lipid metabolism. In comparison to the blood vasculature, the impact of the lymphatics has been underappreciated, both in health and disease, likely due to a less well-delineated anatomy and function. Emerging data suggest that lymphatic dysfunction can be pivotal in the initiation and development of a variety of diseases across broad organ systems. Understanding the clinical associations between lymphatic dysfunction and non-lymphatic morbidity provides valuable evidence for future investigations and may foster the discovery of novel biomarkers and therapies.We retrospectively analysed the electronic medical records of 724 patients referred to the Stanford Center for Lymphatic and Venous Disorders. Patients with an established lymphatic diagnosis were assigned to groups of secondary lymphoedema, lipoedema or primary lymphovascular disease. Individuals found to have no lymphatic disorder were served as the non-lymphatic controls. The prevalence of comorbid conditions was enumerated. Pairwise co-occurrence pattern analyses, validated by Jaccard similarity tests, was utilised to investigate disease-disease interrelationships.Comorbidity analyses underscored the expected relationship between the presence of secondary lymphoedema and those diseases that damage the lymphatics. Cardiovascular conditions were common in all lymphatic subgroups. Additionally, statistically significant alteration of disease-disease interrelationships was noted in all three lymphatic categories when compared to the control population.The presence or absence of a lymphatic disease significantly influences disease interrelationships in the study cohorts. As a physiologic substrate, the lymphatic circulation may be an underappreciated participant in disease pathogenesis. These relationships warrant further, prospective scrutiny and study.

  View details for DOI 10.1002/ctm2.760

  View details for PubMedID 35452183

• Hypoxia and Hypoxia-Inducible Factors in Lymphedema. Frontiers in pharmacology Jiang, X., Tian, W., Kim, D., McQuiston, A. S., Vinh, R., Rockson, S. G., Semenza, G. L., Nicolls, M. R. 2022; 13: 851057

  Abstract

  Lymphedema is a chronic inflammatory disorder characterized by edema, fat deposition, and fibrotic tissue remodeling. Despite significant advances in lymphatic biology research, our knowledge of lymphedema pathology is incomplete. Currently, there is no approved pharmacological therapy for this debilitating disease. Hypoxia is a recognized feature of inflammation, obesity, and fibrosis. Understanding hypoxia-regulated pathways in lymphedema may provide new insights into the pathobiology of this chronic disorder and help develop new medicinal treatments.

  View details for DOI 10.3389/fphar.2022.851057

  View details for PubMedID 35450048

• The COVID-19 Outpatient Pragmatic Platform Study (COPPS): Study design of a multi-center pragmatic platform trial. Contemporary clinical trials Bunning, B., Hedlin, H., Purington, N., Sundaram, V., Kapphahn, K., Weng, Y., Cunanan, K., Maldonado, Y., Singh, U., Khosla, C., O'Hara, R., Nicolls, M., Springman, E., Parsonnet, J., Rogers, A., Levitt, J., Desai, M. 2021: 106509

  Abstract

  More than 3000 clinical trials related to COVID-19 have been registered through clinicaltrials.gov. With so many trials, there is a risk that many will be inconclusive due to being underpowered or due to an inability to recruit patients. At academic medical centers, multiple trials are competing for the same resources; the success of one may come at the expense of another. The COVID-19 Outpatient Pragmatic Protocol Study (COPPS) is a flexible phase 2, multi-site, randomized, blinded trial based at Stanford University designed to overcome these issues by simultaneously evaluating multiple COVID-19 treatments in the outpatient setting in one common platform with shared controls. This approach reduces the overall number of patients required for statistical power, while improving the likelihood that any enrolled patient receives active treatment. The platform study has two main domains designed to evaluate COVID-19 treatments by assessing their ability to reduce viral shedding (Viral Domain), measured with self-collected nasal swabs, or improve clinical outcomes (Clinical Domain), measured through self-reported symptomology data. Data are collected on both domains for all participants enrolled. Participants are followed over a 28-day period. COPPS has the advantage of pragmatism created around its workflow that is also appealing to potential participants because of a lower probability of inactive treatment. At the conclusion of this clinical trial we expect to have identified potentially effective therapeutic strategy/ies for treating COVID-19 in the outpatient setting, which will have a transformative impact on medicine and public health.

  View details for DOI 10.1016/j.cct.2021.106509

  View details for PubMedID 34274494

• The inflammatory role of dysregulated IRS2 in pulmonary vascular remodeling under hypoxic conditions. American journal of physiology. Lung cellular and molecular physiology Nakahara, M., Ito, H., Skinner, J. T., Lin, Q., Tamosiuniene, R., Nicolls, M. R., Keegan, A. D., Johns, R. A., Yamaji-Kegan, K. 2021

  Abstract

  Pulmonary hypertension (PH) is a devastating disease characterized by progressive elevation of pulmonary vascular resistance, right ventricular failure, and ultimately death. We have shown previously that insulin receptor substrate 2 (IRS2), a molecule highly critical to insulin resistance and metabolism, has an anti-inflammatory role in Th2-skewed lung inflammation and pulmonary vascular remodeling. Here, we investigated the hypothesis that IRS2 has an immunomodulatory role in human and experimental PH. Expression analysis showed that IRS2 was significantly decreased in the pulmonary vasculature of patients with pulmonary arterial hypertension and in rat models of PH. In mice, genetic ablation of IRS2 enhanced the hypoxia-induced signaling pathway of Akt and Forkhead box O1 (FOXO1) in the lung tissue and increased pulmonary vascular muscularization, proliferation, and perivascular macrophage recruitment. Furthermore, mice with homozygous IRS2 gene deletion showed a significant gene dosage-dependent increase in pulmonary vascular remodeling and right ventricular hypertrophy in response to hypoxia. Functional studies with bone marrow-derived macrophages isolated from homozygous IRS2 gene-deleted mice showed that hypoxia exposure led to enhancement of the Akt and ERK signaling pathway followed by increases in the pro-PH macrophage activation markers vascular endothelial growth factor-A and arginase 1. Our data suggest that IRS2 contributes to anti-inflammatory effects by regulating macrophage activation and recruitment, which may limit the vascular inflammation, remodeling, and right ventricular hypertrophy that are seen in PH pathology. Restoring the IRS2 pathway may be an effective therapeutic approach for the treatment of PH and right heart failure.

  View details for DOI 10.1152/ajplung.00068.2020

  View details for PubMedID 34189964

• Reply to: Multiple Manifestations of Systemic Sclerosis Affect Walk Distance. American journal of respiratory and critical care medicine Zamanian, R. T., Pinckney, A., Domsic, R. T., Medsger, T., Keyes-Elstein, L., Sweatt, A. J., Welch, B., Goldmuntz, E., Nicolls, M. R., Chung, L., NIH ASC01 Study Group 2021

  View details for DOI 10.1164/rccm.202104-1023LE

  View details for PubMedID 34107229

• The Kinetics of Lymphatic Dysfunction and Leukocyte Expansion in the Draining Lymph Node during LTB4 Antagonism in a Mouse Model of Lymphedema. International journal of molecular sciences Cribb, M. T., Sestito, L. F., Rockson, S. G., Nicolls, M. R., Thomas, S. N., Dixon, J. B. 2021; 22 (9)

  Abstract

  The mechanisms of lymphedema development are not well understood, but emerging evidence highlights the crucial role the immune system plays in driving its progression. It is well known that lymphatic function deteriorates as lymphedema progresses; however, the connection between this progressive loss of function and the immune-driven changes that characterize the disease has not been well established. In this study, we assess changes in leukocyte populations in lymph nodes within the lymphatic drainage basin of the tissue injury site (draining lymph nodes, dLNs) using a mouse tail model of lymphedema in which a pair of draining collecting vessels are left intact. We additionally quantify lymphatic pump function using established near infrared (NIR) lymphatic imaging methods and lymph-draining nanoparticles (NPs) synthesized and employed by our team for lymphatic tissue drug delivery applications to measure lymphatic transport to and resulting NP accumulation within dLNs associated with swelling following surgery. When applied to assess the effects of the anti-inflammatory drug bestatin, which has been previously shown to be a possible treatment for lymphedema, we find lymph-draining NP accumulation within dLNs and lymphatic function to increase as lymphedema progresses, but no significant effect on leukocyte populations in dLNs or tail swelling. These results suggest that ameliorating this loss of lymphatic function is not sufficient to reverse swelling in this surgically induced disease model that better recapitulates the extent of lymphatic injury seen in human lymphedema. It also suggests that loss of lymphatic function during lymphedema may be driven by immune-mediated mechanisms coordinated in dLNs. Our work indicates that addressing both lymphatic vessel dysfunction and immune cell expansion within dLNs may be required to prevent or reverse lymphedema when partial lymphatic function is sustained.

  View details for DOI 10.3390/ijms22094455

  View details for PubMedID 33923272

• Safety and Efficacy of B-Cell Depletion with Rituximab for the Treatment of Systemic Sclerosis Associated Pulmonary Arterial Hypertension: A Multi-center, Double-blind, Randomized, Placebo-controlled Trial. American journal of respiratory and critical care medicine Zamanian, R. T., Badesch, D., Chung, L., Domsic, R. T., Medsger, T., Pinckney, A., Keyes-Elstein, L., D'Aveta, C., Spychala, M., White, R. J., Hassoun, P. M., Torres, F., Sweatt, A. J., Molitor, J. A., Khanna, D., Maecker, H., Welch, B., Goldmuntz, E., Nicolls, M. R., NIH ASC01 Study Group 2021

  Abstract

  RATIONALE: Systemic sclerosis-pulmonary arterial hypertension (SSc-PAH) is one of the most prevalent and deadly forms of PAH. B cells may contribute to SSc pathogenesis.OBJECTIVE: We investigated the safety and efficacy of B-cell depletion for SSc-PAH.METHODS AND MEASUREMENTS: In an NIH-sponsored, multi-center, double-blinded, randomized, placebo-controlled, proof-of-concept trial, 57 SSc-PAH patients on stable-dose standard medical therapy received two infusions of 1000 mg of rituximab or placebo administered two weeks apart. The primary outcome measure was the change in six-minute walk distance (6MWD) at 24 weeks. Secondary endpoints included safety and invasive hemodynamics. We applied a machine learning approach to predict drug-responsiveness.MAIN RESULTS: We randomized 57 subjects from 2010-2018. In the primary analysis, using data through week 24, the adjusted mean change in 6MWD at 24 weeks favored the treatment arm but did not reach statistical significance (23.6±11.1m vs. 0.5±9.7m, p=0.12). While a negative study, when data through week 48 were also considered, the estimated change in 6MWD at week 24 was 25.5±8.8m for rituximab and 0.4±7.4m for placebo (p=0.03). Rituximab treatment appeared to be safe and well tolerated. Low levels of rheumatoid factor (RF), IL-12, and IL-17 were sensitive and specific as favorable predictors of a rituximab response as measured by an improved 6MWD (ROC AUC 0.88-0.95).CONCLUSIONS: B cell depletion therapy is a potentially effective and safe adjuvant treatment for SSc-PAH. Future studies in these patients can confirm whether the identified biomarkers predict rituximab-responsiveness. Clinical trial registration available at www.clinicaltrials.gov, ID: NCT01086540.

  View details for DOI 10.1164/rccm.202009-3481OC

  View details for PubMedID 33651671

• Microvasculature in murine tracheal allografts after combined therapy with clopidogrel and everolimus. Interactive cardiovascular and thoracic surgery Heim, C., Kuckhahn, A., Ramsperger-Gleixner, M., Nicolls, M. R., Weyand, M., Ensminger, S. M. 2021

  Abstract

  OBJECTIVES: Survival after lung transplantation is mainly limited by the development of chronic lung allograft dysfunction. Previous studies have suggested T-cell mediated proliferation and microvascular changes in experimental small airways models as potential therapeutic targets. The aim of this study was to assess microvascular changes in murine orthotopic tracheal allografts after treatment with everolimus alone or in combination with clopidogrel.METHODS: C57Bl/6 (H-2b) donor tracheas were orthotopically transplanted into CBA (H-2k) recipients. Mice received daily injections of everolimus (0.05mg/kg) alone or combined with clopidogrel (1mg/kg). Twenty-eight days after transplantation, ratio of the thickness of tracheal epithelium and lamina propria was measured as an indicator for chronic rejection. Additionally, graft oxygenation and graft perfusion were detected on postoperative days 4, 10 and 28. Quantitative reverse transcription polymerase chain reaction analysis was used for gene expression analysis.RESULTS: While syngeneic grafts showed a stable tissue pO2 and undisturbed microvascular perfusion, rejecting allografts had a drastic decline in both parameters as well as a flattened epithelium and an increased thickness of the lamina propria. Treatment with everolimus reduced allogeneic fibroproliferation, but had no protective effects on the microvasculature; polymerase chain reaction analysis indicated hypoxic stress and inflammation. Combining everolimus with clopidogrel improved microvascular integrity in the tracheal grafts, but had no synergistic effect in preventing obliterative bronchiolitis development.CONCLUSIONS: These data demonstrate that the ability of everolimus to reduce the development of post-transplant obliterative bronchiolitis is not caused by microvascular protection and has no synergistic effects with clopidogrel in acute airway rejection.

  View details for DOI 10.1093/icvts/ivab021

  View details for PubMedID 33550369

• Donor-derived, cell-free DNA levels by next-generation targeted sequencing are elevated in allograft rejection after lung transplantation. ERJ open research Khush, K. K., De Vlaminck, I., Luikart, H., Ross, D. J., Nicolls, M. R. 2021; 7 (1)

  Abstract

  Surveillance after lung transplantation is critical to the detection of acute cellular rejection (ACR) and prevention of chronic lung allograft dysfunction (CLAD). Therefore, we measured donor-derived cell-free DNA (dd-cfDNA) implementing a clinical-grade, next-generation targeted sequencing assay in 107 plasma samples from 38 unique lung transplantation recipients with diagnostic cohorts classified as: (1) biopsy-confirmed or treated ACR, (2) antibody-mediated rejection (AMR), (3) obstructive CLAD, (4) allograft infection (INFXN) and (5) Stable healthy allografts (STABLE). Our principal findings are as follows: (1) dd-cfDNA level was elevated in ACR (median 0.91%; interquartile range (IQR): 0.39-2.07%), CLAD (2.06%; IQR: 0.57-3.67%) and an aggregated cohort of rejection encompassing allograft injury (1.06%; IQR: 0.38-2.51%), compared with the STABLE cohort (0.38%; IQR: 0.23-0.87%) (p=0.02); (2) dd-cfDNA level with AMR was elevated (1.34%; IQR: 0.34-2.40%) compared to STABLE, although it did not reach statistical significance (p=0.07) due to limitations in sample size; (3) there was no difference in dd-cfDNA for allograft INFXN (0.39%; IQR: 0.18-0.67%) versus STABLE, which may relate to differences in "tissue injury" with the spectrum of bronchial colonisation versus invasive infection; (4) there was no difference for dd-cfDNA in unilateral versus bilateral lung transplantation; (5) "optimal threshold" for dd-cfDNA for aggregated rejection events representing allograft injury was determined as 0.85%, with sensitivity=55.6%, specificity=75.8%, positive predictive value (PPV)=43.3% and negative predictive value (NPV)=83.6%. Measurement of plasma dd-cfDNA may be a clinically useful tool for the assessment of lung allograft health and surveillance for "tissue injury" with a spectrum of rejection.

  View details for DOI 10.1183/23120541.00462-2020

  View details for PubMedID 33532456

• Severe Pulmonary Arterial Hypertension is Characterized by Increased Neutrophil Elastase and Relative Elafin Deficiency. Chest Sweatt, A. J., Miyagawa, K., Rhodes, C. J., Taylor, S., Del Rosario, P. A., Hsi, A., Haddad, F., Spiekerkoetter, E., Bental-Roof, M., Bland, R. D., Swietlik, E. M., Gräf, S., Wilkins, M. R., Morrell, N. W., Nicolls, M. R., Rabinovitch, M., Zamanian, R. T. 2021

  Abstract

  Preclinical evidence implicates neutrophil elastase (NE) in PAH pathogenesis, and the NE inhibitor elafin is under early therapeutic investigation.Are circulating NE and elafin levels abnormal in PAH and associated with clinical severity?. In an observational Stanford University PAH cohort (N=249), plasma NE and elafin were measured in comparison to healthy controls (N=106) then related to clinical features and relevant ancillary biomarkers. Cox regression models were fitted with cubic spline functions to associate NE and elafin with survival. To validate prognostic relationships, we analyzed two United Kingdom cohorts (N=75, N=357). Mixed effects models evaluated NE and elafin changes during disease progression. Finally, we studied effects of NE/elafin balance on pulmonary artery endothelial cells (PAECs) from PAH patients.Relative to controls, patients had increased NE (205.1 [123.6-387.3] vs. 97.6 [74.4-126.6] ng/mL, P<0.0001) and decreased elafin (32.0 [15.3-59.1] vs. 45.5 [28.1-92.8] ng/mL, P<0.0001) independent of PAH subtype, illness duration, and therapies. Higher NE associated with worse symptom severity, shorter six-minute walk distance, higher NT-proBNP, greater right ventricular dysfunction, worse hemodynamics, increased circulating neutrophils, elevated cytokine levels, and lower blood BMPR2 expression. In Stanford patients, NE>168.5 ng/mL portended increased mortality risk after adjustment for known clinical predictors (HR 2.52, CI 1.36-4.65, P=0.003) or prognostic cytokines (HR 2.63, CI 1.42-4.87, P=0.001), and NE added incremental value to established PAH risk scores. Similar prognostic thresholds were identified in validation cohorts. Longitudinal NE changes tracked with clinical trends and outcomes. PAH-PAECs exhibited increased apoptosis and attenuated angiogenesis when exposed to NE at the level observed in patients' blood. Elafin rescued PAEC homeostasis, yet the required dose exceeded levels found in patients.NE is increased and elafin deficient across PAH subtypes. NE associates with disease severity and outcomes, and this target-specific biomarker could facilitate therapeutic development of elafin.

  View details for DOI 10.1016/j.chest.2021.06.028

  View details for PubMedID 34181952

• Colorectal Cancer-Associated Microbiome Patterns and Signatures. Frontiers in genetics Zhao, L., Cho, W. C., Nicolls, M. R. 1800; 12: 787176

  Abstract

  The gut microbiome is dynamic and shaped by diet, age, geography, and environment. The disruption of normal gut microbiota (dysbiosis) is closely related to colorectal cancer (CRC) risk and progression. To better identify and characterize CRC-associated dysbiosis, we collected six independent cohorts with matched normal pairs (when available) for comparison and exploration of the microbiota and their interactions with the host. Comparing the microbial community compositions between cancerous and adjacent noncancerous tissues, we found that more microbes were depleted than enriched in tumors. Despite taxonomic variations among cohorts, consistent depletion of normal microbiota (members of Clostridia and Bacteroidia) and significant enrichment of oral-originated pathogens (such as Fusobacterium nucleatum and Parvimonas micra) were observed in CRC compared to normal tissues. Sets of hub and hub-connecting microbes were subsequently identified to infer microbe-microbe interaction networks in CRC. Furthermore, biclustering was used for identifying coherent patterns between patients and microbes. Two patient-microbe interaction patterns, named P0 and P1, can be consistently identified among the investigated six CRC cohorts. Characterization of the microbial community composition of the two patterns revealed that patients in P0 and P1 differed significantly in microbial alpha and beta diversity, and CRC-associated microbiota changes consist of continuous populations of widespread taxa rather than discrete enterotypes. In contrast to the P0, the patients in P1 have reduced microbial alpha diversity compared to the adjacent normal tissues, and P1 possesses more oral-related pathogens than P0 and controls. Collectively, our study investigated the CRC-associated microbiome changes, and identified reproducible microbial signatures across multiple independent cohorts. More importantly, we revealed that the CRC heterogeneity can be partially attributed to the variety and compositional differences of microbes and their interactions to humans.

  View details for DOI 10.3389/fgene.2021.787176

  View details for PubMedID 35003221

• The Role of Regulatory T Cells in Pulmonary Arterial Hypertension. Frontiers in immunology Tian, W., Jiang, S. Y., Jiang, X., Tamosiuniene, R., Kim, D., Guan, T., Arsalane, S., Pasupneti, S., Voelkel, N. F., Tang, Q., Nicolls, M. R. 2021; 12: 684657

  Abstract

  Pulmonary arterial hypertension (PAH) is a chronic, incurable condition characterized by pulmonary vascular remodeling, perivascular inflammation, and right heart failure. Regulatory T cells (Tregs) stave off autoimmunity, and there is increasing evidence for their compromised activity in the inflammatory milieu of PAH. Abnormal Treg function is strongly correlated with a predisposition to PAH in animals and patients. Athymic Treg-depleted rats treated with SU5416, an agent causing pulmonary vascular injury, develop PAH, which is prevented by infusing missing CD4+CD25highFOXP3+ Tregs. Abnormal Treg activity may also explain why PAH disproportionately affects women more than men. This mini review focuses on the role of Tregs in PAH with a special view to sexual dimorphism and the future promise of Treg therapy.

  View details for DOI 10.3389/fimmu.2021.684657

  View details for PubMedID 34489935

• Pulmonary Arterial Hypertension: Diagnosis, Treatment, and Novel Advances. American journal of respiratory and critical care medicine Maron, B. A., Abman, S. H., Elliott, C. G., Frantz, R. P., Hopper, R. K., Horn, E. M., Nicolls, M. R., Shlobin, O. A., Shah, S. J., Kovacs, G. n., Olschewski, H. n., Rosenzweig, E. B. 2021

  Abstract

  The diagnosis and management of pulmonary arterial hypertension (PAH) includes several advances, such as broader recognition of extra-pulmonary vascular organ system involvement, validated point-of-care clinical assessment tools, and a focus on early-initiation of multiple pharmacotherapeutics in appropriate patients. Indeed, a principal goal in PAH today is early diagnosis for prompt initiation of treatment to achieve minimal symptom burden, optimize the patient's biochemical, hemodynamic, and functional profile, and limit adverse events. To accomplish this end, clinicians must be familiar with novel risk factors and the revised hemodynamic definition for PAH. Fresh insights into the role of developmental biology (i.e., perinatal health) may also be useful for predicting incident PAH in early adulthood. Emergent or underutilized approaches to PAH management include a novel TGF-β ligand trap pharmacotherapy, remote pulmonary artery pressure monitoring, next-generation imaging using inert gas-based magnetic resonance and other technologies, right atrial pacing, and pulmonary artery denervation. These and other PAH state-of-the-art advances are summarized here for the wider pulmonary medicine community.

  View details for DOI 10.1164/rccm.202012-4317SO

  View details for PubMedID 33861689

• Leukotrienes in Tumor-Associated Inflammation. Frontiers in pharmacology Tian, W., Jiang, X., Kim, D., Guan, T., Nicolls, M. R., Rockson, S. G. 2020; 11: 1289

  Abstract

  Leukotrienes are biologically active eicosanoid lipid mediators that originate from oxidative metabolism of arachidonic acid. Biosynthesis of leukotrienes involves a set of soluble and membrane-bound enzymes that constitute a machinery complex primarily expressed by cells of myeloid origin. Leukotrienes and their synthetic enzymes are critical immune modulators for leukocyte migration. Increased concentrations of leukotrienes are implicated in a number of inflammatory disorders. More recent work indicates that leukotrienes may also interact with a variety of tissue cells, contributing to the low-grade inflammation of cardiovascular, neurodegenerative, and metabolic conditions, as well as that of cancer. Leukotriene signaling contributes to the active tumor microenvironment, promoting tumor growth and resistance to immunotherapy. This review summarizes recent insights into the intricate roles of leukotrienes in promoting tumor growth and metastasis through shaping the tumor microenvironment. The emerging possibilities for pharmacological targeting of leukotriene signaling in tumor metastasis are considered.

  View details for DOI 10.3389/fphar.2020.01289

  View details for PubMedID 32973519

  View details for PubMedCentralID PMC7466732

• Leukotrienes in Tumor-Associated Inflammation FRONTIERS IN PHARMACOLOGY Tian, W., Jiang, X., Kim, D., Guan, T., Nicolls, M. R., Rockson, S. G. 2020; 11

  View details for DOI 10.3389/fphar.2020.01289

  View details for Web of Science ID 000566179100001

• Endothelial HIF-2alpha as a Key Endogenous Mediator Preventing Emphysema. American journal of respiratory and critical care medicine Pasupneti, S., Tian, W., Tu, A. B., Dahms, P., Granucci, E., Gandjeva, A., Xiang, M., Butcher, E., Semenza, G. L., Tuder, R., Jiang, X., Nicolls, M. R. 2020

  Abstract

  RATIONALE: Endothelial injury may provoke emphysema, but molecular pathways of disease development require further discernment. Emphysema lungs exhibit decreased expression of hypoxia inducible factor-2alpha (HIF-2alpha)-regulated genes, and tobacco smoke decreases pulmonary HIF-2alpha levels. These findings suggest that decreased HIF-2alpha expression is important in the development of emphysema.OBJECTIVES: The objective of this study was to evaluate the roles of endothelial cell (EC) HIF-2alpha in the pathogenesis of emphysema in mice.METHODS: Mouse lungs were examined for emphysema following either the loss or overexpression of EC Hif-2alpha. Additionally, SU5416, a VEGFR2 inhibitor, was used to induce emphysema. Lungs were evaluated for hepatocyte growth factor (HGF), a protein involved in alveolar development and homeostasis. Patient emphysema lungs were measured for endothelial HIF-2alpha expression.MEASUREMENTS AND MAIN RESULTS: EC Hif-2alpha deletion resulted in emphysema, in association with fewer ECs and pericytes. Following SU5416 exposure, EC Hif-2alpha knockout mice developed more severe emphysema, whereas EC Hif-2alpha-overexpressing mice were protected. EC Hif-2alpha knockout mice demonstrated lower levels of HGF. Human emphysema lung samples exhibited reduced EC HIF-2alpha expression.CONCLUSIONS: Here, we demonstrate a unique, protective role for pulmonary endothelial HIF-2alpha and how decreased expression of this endogenous factor causes emphysema; its pivotal protective function is suggested by its ability to overcome VEGF antagonism. HIF-2alpha may maintain alveolar architecture by promoting vascular survival and associated HGF production. In summary, HIF-2alpha may be a key endogenous factor that prevents the development of emphysema, and its upregulation has the potential to foster lung health in at-risk patients.

  View details for DOI 10.1164/rccm.202001-0078OC

  View details for PubMedID 32515984

• The Hallmarks of Severe Pulmonary Arterial Hypertension: The Cancer Hypothesis - Ten years later. American journal of physiology. Lung cellular and molecular physiology Cool, C. D., Kuebler, W. M., Bogaard, H. J., Spiekerkoetter, E., Nicolls, M. R., Voelkel, N. F. 2020

  Abstract

  Severe forms of pulmonary arterial hypertension (PAH) are most frequently the consequence of a lumen-obliterating angiopathy. One pathobiological model is, that the initial pulmonary vascular endothelial cell injury and apoptosis is followed by the evolution of phenotypically altered, apoptosis-resistant, proliferating cells and an inflammatory vascular immune response. Although there may be a vasoconstrictive disease component, the increased pulmonary vascular shear stress in established PAH is caused largely by the vascular wall pathology. In this review, we revisit the "quasi-malignancy concept" of severe PAH and examine to what extent the hallmarks of PAH can be compared to the hallmarks of cancer. The cancer model of severe PAH, based on the growth of abnormal vascular and bone marrow-derived cells, may enable the emergence of novel cell-based PAH treatment strategies.

  View details for DOI 10.1152/ajplung.00476.2019

  View details for PubMedID 32023082

• Decreased lymphatic HIF-2α accentuates lymphatic remodeling in lymphedema. The Journal of clinical investigation Jiang, X. n., Tian, W. n., Granucci, E. J., Tu, A. B., Kim, D. n., Dahms, P. n., Pasupneti, S. n., Peng, G. n., Kim, Y. n., Lim, A. H., Espinoza, F. H., Cribb, M. n., Dixon, J. B., Rockson, S. G., Semenza, G. L., Nicolls, M. R. 2020

  Abstract

  Pathologic lymphatic remodeling in lymphedema evolves during periods of tissue inflammation and hypoxia through poorly defined processes. In human and mouse lymphedema, there is a significant increase of hypoxia inducible factor (HIF)-1α, but a reduction of HIF-2α protein expression in lymphatic endothelial cells (LECs). We questioned whether dysregulated expression of these transcription factors contributes to disease pathogenesis and found that LEC-specific deletion of Hif-2α exacerbated lymphedema pathology. Even without lymphatic vascular injury, the loss of LEC-specific Hif-2α caused anatomic pathology and a functional decline in fetal and adult mice. These findings suggest that HIF-2α is an important mediator of lymphatic health. HIF-2α promoted protective phosphorylated TIE2 (p-TIE2) signaling in LECs, a process also replicated by upregulating TIE2 signaling through adenovirus-mediated angiopoietin-1 (Angpt1) gene therapy. Our study suggests that HIF-2α normally promotes healthy lymphatic homeostasis and raises the exciting possibility that restoring HIF-2α pathways in lymphedema could mitigate long-term pathology and disability.

  View details for DOI 10.1172/JCI136164

  View details for PubMedID 32673288

• From 2D to 3D: Promising Advances in Imaging Lung Structure. Frontiers in medicine Klouda, T. n., Condon, D. n., Hao, Y. n., Tian, W. n., Lvova, M. n., Chakraborty, A. n., Nicolls, M. R., Zhou, X. n., Raby, B. A., Yuan, K. n. 2020; 7: 343

  Abstract

  The delicate structure of murine lungs poses many challenges for acquiring high-quality images that truly represent the living lung. Here, we describe several optimized procedures for obtaining and imaging murine lung tissue. Compared to traditional paraffin cross-section and optimal cutting temperature (OCT), agarose-inflated vibratome sections (aka precision-cut lung slices), combines comparable structural preservation with experimental flexibility. In particular, we discuss an optimized procedure to precision-cut lung slices that can be used to visualize three-dimensional cell-cell interactions beyond the limitations of two-dimensional imaging. Super-resolution microscopy can then be used to reveal the fine structure of lung tissue's cellular bodies and processes that regular confocal cannot. Lastly, we evaluate the entire lung vasculature with clearing technology that allows imaging of the entire volume of the lung without sectioning. In this manuscript, we combine the above procedures to create a novel and evolutionary method to study cell behavior ex vivo, trace and reconstruct pulmonary vasculature, address fundamental questions relevant to a wide variety of vascular disorders, and perceive implications to better imaging clinical tissue.

  View details for DOI 10.3389/fmed.2020.00343

  View details for PubMedID 32766264

  View details for PubMedCentralID PMC7381109

• Mural Cell SDF1 Signaling is Associated with the Pathogenesis of Pulmonary Arterial Hypertension. American journal of respiratory cell and molecular biology Yuan, K. n., Liu, Y. n., Zhang, Y. n., Nathan, A. n., Tian, W. n., Yu, J. n., Sweatt, A. J., Condon, D. n., Chakraborty, A. n., Agarwal, S. n., Auer, N. n., Zhang, S. n., Wu, J. C., Zamanian, R. T., Nicolls, M. R., de Jesus Perez, V. A. 2020

  Abstract

  Pulmonary artery smooth muscle cells (PASMCs) and pericytes are NG2+ mural cells that provide structural support to pulmonary arteries and capillaries. In pulmonary arterial hypertension (PAH), both mural cell types contribute to PA muscularization but whether similar mechanisms are responsible for their behavior is unknown.RNA-Seq was used to compare the gene profile of pericytes and PASMCs from PAH and healthy lungs. NG2-Cre-ER mice were used to generate NG2-selective reporter mice (NG2tdT) for cell lineage identification and tamoxifen-inducible mice for NG2-selective SDF1 knockout (SDF1NG2-KO).Hierarchical clustering of RNA-seq data demonstrated that the genetic profile of PAH pericytes and PASMCs is highly similar. Cellular lineage staining studies on NG2tdT mice in chronic hypoxia showed that similar to PAH, tdT+ cells accumulate in muscularized microvessels and demonstrate significant upregulation of SDF1, a chemokine involved in chemotaxis and angiogenesis. Compared to controls, SDF1NG2-KO mice in chronic hypoxia had reduced muscularization and lower abundance of NG2+ cells around microvessels. SDF1 stimulation in healthy pericytes induced greater contractility and impaired their capacity to establish endothelial-pericyte communications. In contrast, SDF1 knockdown reduced PAH pericyte contractility and improved their capacity to associate with vascular tubes in co-culture.SDF1 is upregulated in NG2+ mural cells and is associated with PA muscularization. Targeting SDF1 could help prevent and/or reverse muscularization in PAH.

  View details for DOI 10.1165/rcmb.2019-0401OC

  View details for PubMedID 32084325

• Machine learning algorithms to differentiate among pulmonary complications after hematopoietic cell transplant. Chest Sharifi, H. n., Lai, Y. K., Guo, H. n., Hoppenfeld, M. n., Guenther, Z. D., Johnston, L. n., Brondstetter, T. n., Chhatwani, L. n., Nicolls, M. R., Hsu, J. L. 2020

  Abstract

  Pulmonary complications, including infections, are highly prevalent in patients after hematopoietic cell transplant with chronic graft-versus-host disease. These comorbid diseases can make the diagnosis of early lung graft-versus-host disease (bronchiolitis obliterans syndrome) challenging. A quantitative method to differentiate among these pulmonary diseases can address diagnostic challenges and facilitate earlier and more targeted therapy.We conducted a single center study of 66 patients with computed tomography chest scans analyzed with a quantitative imaging tool known as parametric response mapping. Parametric response mapping results were correlated with pulmonary function tests and clinical characteristics. Five parametric response mapping metrics were applied to K-means clustering and support vector machine models to distinguish among post-transplant lung complications solely from quantitative output.Compared to parametric response mapping, spirometry showed a moderate correlation with radiographic air trapping, and total lung capacity and residual volume showed a strong correlation with radiographic lung volumes. K-means clustering analysis distinguished 4 unique clusters. Clusters 2 and 3 represented obstructive physiology (encompassing 81% of patients with bronchiolitis obliterans syndrome) in increasing severity (percent air trapping 15.6% and 43.0%, respectively). Cluster 1 was dominated by normal lung, and cluster 4 was characterized by patients with parenchymal opacities. A support vector machine algorithm differentiated bronchiolitis obliterans syndrome with specificity of 88%, sensitivity of 83%, accuracy of 86% and an area under the receiver operating characteristic curve of 0.85.Our machine learning models offer a quantitative approach for the identification of bronchiolitis obliterans syndrome versus other lung diseases, including late pulmonary complications after hematopoietic cell transplant.

  View details for DOI 10.1016/j.chest.2020.02.076

  View details for PubMedID 32343962

• IPSE, an abundant egg-secreted protein of the carcinogenic helminth Schistosoma haematobium, promotes proliferation of bladder cancer cells and angiogenesis. Infectious agents and cancer Mbanefo, E. C., Agbo, C. T., Zhao, Y., Lamanna, O. K., Thai, K. H., Karinshak, S. E., Khan, M. A., Fu, C., Odegaard, J. I., Saltikova, I. V., Smout, M. J., Pennington, L. F., Nicolls, M. R., Jardetzky, T. S., Loukas, A., Brindley, P. J., Falcone, F. H., Hsieh, M. H. 2020; 15: 63

  Abstract

  Background: Schistosoma haematobium, the helminth causing urogenital schistosomiasis, is a known bladder carcinogen. Despite the causal link between S. haematobium and bladder cancer, the underlying mechanisms are poorly understood. S. haematobium oviposition in the bladder is associated with angiogenesis and urothelial hyperplasia. These changes may be pre-carcinogenic events in the bladder. We hypothesized that the Interleukin-4-inducing principle of Schistosoma mansoni eggs (IPSE), an S. haematobium egg-secreted "infiltrin" protein that enters host cell nuclei to alter cellular activity, is sufficient to induce angiogenesis and urothelial hyperplasia. Methods: Mouse bladders injected with S. haematobium eggs were analyzed via microscopy for angiogenesis and urothelial hyperplasia. Endothelial and urothelial cell lines were incubated with recombinant IPSE protein or an IPSE mutant protein that lacks the native nuclear localization sequence (NLS-) and proliferation measured using CFSE staining and real-time monitoring of cell growth. IPSE's effects on urothelial cell cycle status was assayed through propidium iodide staining. Endothelial and urothelial cell uptake of fluorophore-labeled IPSE was measured. Findings: Injection of S. haematobium eggs into the bladder triggers angiogenesis, enhances leakiness of bladder blood vessels, and drives urothelial hyperplasia. Wild type IPSE, but not NLS-, increases proliferation of endothelial and urothelial cells and skews urothelial cells towards S phase. Finally, IPSE is internalized by both endothelial and urothelial cells. Interpretation: IPSE drives endothelial and urothelial proliferation, which may depend on internalization of the molecule. The urothelial effects of IPSE depend upon its NLS. Thus, IPSE is a candidate pro-carcinogenic molecule of S. haematobium.Summary: Schistosoma haematobium acts as a bladder carcinogen through unclear mechanisms. The S. haematobium homolog of IPSE, a secreted schistosome egg immunomodulatory molecule, enhances angiogenesis and urothelial proliferation, hallmarks of pre-carcinogenesis, suggesting IPSE is a key pro-oncogenic molecule of S. haematobium.

  View details for DOI 10.1186/s13027-020-00331-6

  View details for PubMedID 33101456

• Bone Morphogenetic Protein Receptor 2 Mutations Impair T Regulatory Cell Function and Promote Inflammation in Pulmonary Arterial Hypertension Peng, G., Tian, A., Guan, T., Wu, T., Nicolls, M. R. AMER THORACIC SOC. 2020

  View details for Web of Science ID 000556393502474

• Single-Cell RNA-seq Analysis Reveals Endothelial Heterogeneity of Inflammation-Induced Pulmonary Arterial Hypertension Under Bmpr2 Dysfunction Wu, T., Peng, G., Tian, A., Guan, T., Nicolls, M. R. AMER THORACIC SOC. 2020

  View details for Web of Science ID 000556393502473

• Safety and Efficacy of B-cell Depletion with Rituximab for the Treatment of Systemic Sclerosis-associated Pulmonary Arterial Hypertension in a Multi-center NIH Clinical Trial Nicolls, M., Badesch, D., Chung, L., Domsic, R., Medsger, T., Pinckney, A., Keyes-Elstein, L., D'Aveta, C., Spychala, M., White, R., Hassoun, P., Torres, F., Molitor, J., Khanna, D., Maeker, H., Welch, B., Goldmuntz, E., Zamanian, R., ASC01 Investigators WILEY. 2019

  View details for Web of Science ID 000507466901290

• Late Breaking Abstract - Safety and efficacy of B-cell depletion with rituximab for the treatment of systemic sclerosis-associated pulmonary arterial hypertension Zamanian, R., Badesch, D., Chung, L., Domsic, R., Medsger, T., Pinckney, A., Keyes-Elstein, L., D'Aveta, C., Spychala, M., White, J., Hassoun, P., Torres, F., Molitor, J., Khanna, D., Maeker, H., Welch, B., Goldmuntz, E., Nicolls, M., Asco1 Investigators EUROPEAN RESPIRATORY SOC JOURNALS LTD. 2019

  View details for DOI 10.1183/13993003.congress-2019.RCT1884

  View details for Web of Science ID 000507372408095

• Preservation of Microvascular Integrity in Murine Orthotopic Tracheal Allografts by Clopidogrel TRANSPLANTATION Heim, C., Khan, M., von Silva-Tarouca, B., Kuckhahn, A., Stamminger, T., Ramsperger-Gleixner, M., Nicolls, M. R., Weyand, M., Ensminger, S. M. 2019; 103 (5): 899–908

  View details for DOI 10.1097/TP.0000000000002571

  View details for Web of Science ID 000480680900017

• Inducible expression of immediate early genes is regulated through dynamic chromatin association by NF45/ILF2 and NF90/NF110/ILF3 PLOS ONE Wu, T., Shi, L., Lowe, A. W., Nicolls, M. R., Kao, P. N. 2019; 14 (4)

  View details for DOI 10.1371/journal.pone.0216042

  View details for Web of Science ID 000465519100085

• Loss of Endothelium-Derived Wnt5a Is Associated With Reduced Pericyte Recruitment and Small Vessel Loss in Pulmonary Arterial Hypertension CIRCULATION Yuan, K., Shamskhou, E. A., Orcholski, M. E., Nathan, A., Reddy, S., Honda, H., Mani, V., Zeng, Y., Ozen, M. O., Wang, L., Demirci, U., Tian, W., Nicolls, M. R., Perez, V. 2019; 139 (14): 1710–24

  View details for DOI 10.1161/CIRCULATIONAHA.118.037642

  View details for Web of Science ID 000469320000018

• Discovery of Distinct Immune Phenotypes Using Machine Learning in Pulmonary Arterial Hypertension CIRCULATION RESEARCH Sweatt, A. J., Hedlin, H. K., Balasubramanian, V., Hsi, A., Blum, L. K., Robinson, W. H., Haddad, F., Hickey, P. M., Condliffe, R., Lawrie, A., Nicolls, M. R., Rabinovitch, M., Khatri, P., Zamanian, R. T. 2019; 124 (6): 904–19

  View details for DOI 10.1161/CIRCRESAHA.118.313911

  View details for Web of Science ID 000469341600015

• Preservation of microvascular integrity in murine orthotopic tracheal allografts by clopidogrel. Transplantation Heim, C., Khan, M. A., Silva-Tarouca, B. v., Kuckhahn, A., Stamminger, T., Ramsperger-Gleixner, M., Nicolls, M. R., Weyand, M., Ensminger, S. M. 2019

  Abstract

  BACKGROUND: Survival after lung transplantation is mainly limited by the development of chronic lung allograft dysfunction (CLAD). The aim of this study was to investigate if platelet inhibition by clopidogrel has a functionally relevant influence on the microvascular integrity of orthotopic tracheal allografts as an anatomic basis for the development of CLAD.METHODS: We orthotopically transplanted C57Bl/6 (H-2) tracheas into CBA.J (H-2) recipients which afterwards received clopidogrel (1mg/kg). Morphometric analysis was performed by measuring epithelial height in proportion to thickness of the lamina propria (ELR). Tissue oxygenation was determined using a fluorescence quenching technique and graft perfusion monitoring was performed by Laser Doppler Flowmetry and lectin-binding assay. Immunohistochemistry was used for detection of CD31 and iNOS while iron deposition was shown with Prussian blue reaction. Quantitative RT-PCR analysis was used for gene expression analysis.RESULTS: Isografts maintained good oxygenation and perfusion throughout the experiment, while both were drastically reduced in allografts. Treatment with clopidogrel attenuated graft hypoxia and reduced loss of perfusion. Additionally, clopidogrel led to increased ELR while iron deposition was impaired. Gene expression analysis revealed elevated levels of angiogenic VEGF in the clopidogrel group. Improved endothelial function shown by immunohistochemistry (CD31, iNOS).CONCLUSIONS: Continuous administration of clopidogrel significantly improved tissue oxygenation, limited microvascular leakiness, and prevented airway ischemia. These data demonstrate that clopidogrel ameliorates microvascular injury during acute airway rejection which is a known predisposing factor for the development of CLAD.

  View details for PubMedID 30801550

• Anti-hyperlipidaemic effects of synthetic analogues of nordihydroguaiaretic acid in dyslipidaemic rats BRITISH JOURNAL OF PHARMACOLOGY Singh, M., Bittner, S., Li, Y., Bittner, A., Han, L., Cortez, Y., Inayathullah, M., Arif, Z., Parthasarathi, R., Rajadas, J., Shen, W., Nicolls, M. R., Kraemer, F. B., Azhar, S. 2019; 176 (3): 369–85

  View details for DOI 10.1111/bph.14528

  View details for Web of Science ID 000455517100003

• Airway hypoxia in lung transplantation CURRENT OPINION IN PHYSIOLOGY Pasupneti, S., Nicolls, M. R. 2019; 7: 21–26

  View details for DOI 10.1016/j.cophys.2018.12.002

  View details for Web of Science ID 000471295100005

• Endothelial Hypoxia-Inducible Factor-2 Is Required for the Maintenance of Airway Microvasculature CIRCULATION Jiang, X., Tian, W., Tu, A. B., Pasupneti, S., Shuffle, E., Dahms, P., Zhang, P., Cai, H., Dinh, T. T., Liu, B., Cain, C., Giaccia, A. J., Butcher, E. C., Simon, M., Semenza, G. L., Nicolls, M. R. 2019; 139 (4): 502-517

  View details for DOI 10.1161/CIRCULATIONAHA.118.036157

  View details for Web of Science ID 000459430400012

• The Lymphatic System in Obesity, Insulin Resistance, and Cardiovascular Diseases. Frontiers in physiology Jiang, X. n., Tian, W. n., Nicolls, M. R., Rockson, S. G. 2019; 10: 1402

  Abstract

  Obesity, insulin resistance, dyslipidemia, and hypertension are fundamental clinical manifestations of the metabolic syndrome. Studies over the last few decades have implicated chronic inflammation and microvascular remodeling in the development of obesity and insulin resistance. Newer observations, however, suggest that dysregulation of the lymphatic system underlies the development of the metabolic syndrome. This review summarizes recent advances in the field, discussing how lymphatic abnormality promotes obesity and insulin resistance, and, conversely, how the metabolic syndrome impairs lymphatic function. We also discuss lymphatic biology in metabolically dysregulated diseases, including type 2 diabetes, atherosclerosis, and myocardial infarction.

  View details for DOI 10.3389/fphys.2019.01402

  View details for PubMedID 31798464

  View details for PubMedCentralID PMC6868002

• Pathology and pathobiology of pulmonary hypertension: state of the art and research perspectives Humbert, M., Guignabert, C., Bonnet, S., Dorfmuller, P., Klinger, J. R., Nicolls, M. R., Olschewski, A. J., Pullamsetti, S. S., Schermuly, R. T., Stenmark, K. R., Rabinovitch, M. EUROPEAN RESPIRATORY SOC JOURNALS LTD. 2019

  View details for DOI 10.1183/13993003.01887-2018

  View details for Web of Science ID 000458462600012

• Phenotypically-Silent Bone Morphogenetic Protein Receptor 2 (Bmpr2) Mutations Predispose Rats to Inflammation-Induced Pulmonary Arterial Hypertension by Enhancing The Risk for Neointimal Transformation. Circulation Tian, W. n., Jiang, X. n., Sung, Y. K., Shuffle, E. n., Wu, T. H., Kao, P. N., Tu, A. B., Dorfmüller, P. n., Cao, A. n., Wang, L. n., Peng, G. n., Kim, Y. n., Zhang, P. n., Chappell, J. n., Pasupneti, S. n., Dahms, P. n., Maguire, P. n., Chaib, H. n., Zamanian, R. n., Peters-Golden, M. n., Snyder, M. P., Voelkel, N. F., Humbert, M. n., Rabinovitch, M. n., Nicolls, M. R. 2019

  Abstract

  Bmpr2 mutations are critical risk factors for hereditary pulmonary arterial hypertension (hPAH) with approximately 20% of carriers developing disease. There is an unmet medical need to understand how environmental factors, such as inflammation, render Bmpr2 mutants susceptible to PAH. Overexpressing 5-lipoxygenase (5-LO) provokes lung inflammation and transient PAH in Bmpr2+/- mice. Accordingly, 5-LO and its metabolite, leukotriene B4 (LTB4), are candidates for the 'second hit'. The purpose of this study was to determine how 5-LO-mediated pulmonary inflammation synergized with phenotypically-silent Bmpr2 defects to elicit significant pulmonary vascular disease in rats.Monoallelic Bmpr2 mutant rats were generated and found phenotypically normal for up to one year of observation. To evaluate whether a second hit would elicit disease, animals were exposed to 5-LO-expressing adenovirus (AdAlox5), monocrotaline, SU5416, SU5416 with chronic hypoxia or chronic hypoxia alone. Bmpr2-mutant hPAH patient samples were assessed for neointimal 5-LO expression. Pulmonary artery endothelial cells (PAECs) with impaired BMPR2 signaling were exposed to increased 5-LO-mediated inflammation and were assessed for phenotypic and transcriptomic changes.Lung inflammation, induced by intratracheal delivery of AdAlox5, elicited severe PAH with intimal remodeling in Bmpr2+/- rats but not in their wild-type littermates. Neointimal lesions in the diseased Bmpr2+/- rats gained endogenous 5-LO expression associated with elevated LTB4 biosynthesis. Bmpr2-mutant hPAH patients similarly expressed 5-LO in the neointimal cells. In vitro, BMPR2 deficiency, compounded by 5-LO-mediated inflammation, generated apoptosis-resistant, and proliferative PAECs with mesenchymal characteristics. These transformed cells expressed nuclear envelope-localized 5-LO consistent with induced LTB4 production, as well as a transcriptomic signature similar to clinical disease, including upregulated NF-κB, IL-6, and TGF-β signaling pathways. The reversal of PAH and vasculopathy in Bmpr2 mutants by TGF-β antagonism suggests that TGF-β is critical for neointimal transformation.In a new 'two-hit' model of disease, lung inflammation induced severe PAH pathology in Bmpr2+/- rats. Endothelial transformation required the activation of canonical and noncanonical TGF-β signaling pathways and was characterized by 5-LO nuclear envelope translocation with enhanced LTB4 production. This study offers one explanation of how an environmental injury unleashes the destructive potential of an otherwise-silent genetic mutation.

  View details for DOI 10.1161/CIRCULATIONAHA.119.040629

  View details for PubMedID 31462075

• Inducible expression of immediate early genes is regulated through dynamic chromatin association by NF45/ILF2 and NF90/NF110/ILF3. PloS one Wu, T. H., Shi, L. n., Lowe, A. W., Nicolls, M. R., Kao, P. N. 2019; 14 (4): e0216042

  Abstract

  Immediate early gene (IEG) transcription is rapidly activated by diverse stimuli. This transcriptional regulation is assumed to involve constitutively expressed nuclear factors that are targets of signaling cascades initiated at the cell membrane. NF45 (encoded by ILF2) and its heterodimeric partner NF90/NF110 (encoded by ILF3) are chromatin-interacting proteins that are constitutively expressed and localized predominantly in the nucleus. Previously, NF90/NF110 chromatin immunoprecipitation followed by deep sequencing (ChIP-seq) in K562 erythroleukemia cells revealed its enriched association with chromatin at active promoters and strong enhancers. NF90/NF110 specifically occupied the promoters of IEGs. Here, ChIP in serum-starved HEK293 cells demonstrated that NF45 and NF90/NF110 pre-exist and specifically occupy the promoters of IEG transcription factors EGR1, FOS and JUN. Cellular stimulation with phorbol myristyl acetate increased NF90/NF110 chromatin association, while decreasing NF45 chromatin association at promoters of EGR1, FOS and JUN. In HEK293 cells stably transfected with doxycycline-inducible shRNA vectors targeting NF90/NF110 or NF45, doxycycline-mediated knockdown of NF90/NF110 or NF45 attenuated the inducible expression of EGR1, FOS, and JUN at the levels of transcription, RNA and protein. Dynamic chromatin association of NF45 and NF90/NF110 at IEG promoters are observed upon stimulation, and NF45 and NF90/NF110 contribute to inducible transcription of IEGs. NF45 and NF90/NF110 operate as chromatin regulators of the immediate early response.

  View details for PubMedID 31022259

• Discovery of Distinct Immune Phenotypes Using Machine Learning in Pulmonary Arterial Hypertension. Circulation research Sweatt, A. J., Hedlin, H. K., Balasubramanian, V. n., Hsi, A. n., Blum, L. K., Robinson, W. H., Haddad, F. n., Hickey, P. M., Condliffe, R. A., Lawrie, A. n., Nicolls, M. R., Rabinovitch, M. n., Khatri, P. n., Zamanian, R. T. 2019

  Abstract

  Accumulating evidence implicates inflammation in pulmonary arterial hypertension (PAH) and therapies targeting immunity are under investigation, though it remains unknown if distinct immune phenotypes exist.Identify PAH immune phenotypes based on unsupervised analysis of blood proteomic profiles.In a prospective observational study of Group 1 PAH patients evaluated at Stanford University (discovery cohort, n=281) and University of Sheffield (validation cohort, n=104) between 2008-2014, we measured a circulating proteomic panel of 48 cytokines, chemokines, and factors using multiplex immunoassay. Unsupervised machine learning (consensus clustering) was applied in both cohorts independently to classify patients into proteomic immune clusters, without guidance from clinical features. To identify central proteins in each cluster, we performed partial correlation network analysis. Clinical characteristics and outcomes were subsequently compared across clusters. Four PAH clusters with distinct proteomic immune profiles were identified in the discovery cohort. Cluster 2 (n=109) had low cytokine levels similar to controls. Other clusters had unique sets of upregulated proteins central to immune networks- cluster 1 (n=58)(TRAIL, CCL5, CCL7, CCL4, MIF), cluster 3 (n=77)(IL-12, IL-17, IL-10, IL-7, VEGF), and cluster 4 (n=37)(IL-8, IL-4, PDGF-β, IL-6, CCL11). Demographics, PAH etiologies, comorbidities, and medications were similar across clusters. Non-invasive and hemodynamic surrogates of clinical risk identified cluster 1 as high-risk and cluster 3 as low-risk groups. Five-year transplant-free survival rates were unfavorable for cluster 1 (47.6%, CI 35.4-64.1%) and favorable for cluster 3 (82.4%, CI 72.0-94.3%)(across-cluster p<0.001). Findings were replicated in the validation cohort, where machine learning classified four immune clusters with comparable proteomic, clinical, and prognostic features.Blood cytokine profiles distinguish PAH immune phenotypes with differing clinical risk that are independent of World Health Organization Group 1 subtypes. These phenotypes could inform mechanistic studies of disease pathobiology and provide a framework to examine patient responses to emerging therapies targeting immunity.

  View details for PubMedID 30661465

• High Dose Ubenimex Interferes with the Efficacy of Sildenafil in Experimental Pulmonary Hypertension Dahms, P., Tian, A., Zhang, P., Tu, A. B., Jiang, X., Pasupneti, S., Peng, G., Nicolls, M. R. AMER THORACIC SOC. 2019

  View details for Web of Science ID 000466776701245

• The Role of Iron-Induced Macrophage Dysregulation in Aspergillus Fumigatus Invasion in Airway Transplantation Matthaiou, E., Manouvakhova, O. M., Sinha, M., Tu, A. B., Clemons, K. V., Stevens, D. A., Nicolls, M. R., Hsu, J. L. AMER THORACIC SOC. 2019

  View details for Web of Science ID 000466771102508

• HIF1 alpha-Mediated Lymphangiogenesis Influences Airway Transplant Rejection Tu, A. B., Jiang, X., Tian, A., Dahms, P., Zhang, P., Pasupneti, S., Nicolls, M. R. AMER THORACIC SOC. 2019

  View details for Web of Science ID 000466771103173

• Pilot studies demonstrate the potential benefits of antiinflammatory therapy in human lymphedema JCI INSIGHT Rockson, S. G., Tian, W., Jiang, X., Kuznetsova, T., Haddad, F., Zampell, J., Mehrara, B., Sampson, J. P., Roche, L., Kim, J., Nicolls, M. R. 2018; 3 (20)

  View details for DOI 10.1172/jci.insight.123775

  View details for Web of Science ID 000447709700026

• Endothelial HIF-2alpha is Required for the Maintenance of Airway Microvasculature. Circulation Jiang, X., Tian, W., Tu, A. B., Pasupneti, S., Shuffle, E., Dahms, P., Zhang, P., Cai, H., Dinh, T. T., Liu, B., Cain, C., Giaccia, A. J., Butcher, E. C., Simon, C., Semenza, G. L., Nicolls, M. R. 2018

  Abstract

  BACKGROUND: Hypoxia-inducible factors (HIFs), especially HIF-1alpha and HIF-2alpha, are key mediators of the adaptive response to hypoxic stress and play essential roles in maintaining lung homeostasis. Human and animal genetics studies confirm that abnormal HIF correlates with pulmonary vascular pathology and chronic lung diseases, but it remains unclear whether endothelial cell (EC) HIF production is essential for microvascular health. The large airway has an ideal circulatory bed for evaluating histologic changes and physiology in genetically-modified rodents.METHODS: The tracheal microvasculature of mice, with conditionally-deleted or overexpressed HIF-1alpha or HIF-2alpha, was evaluated for anatomy, perfusion, and permeability. Angiogenic signaling studies assessed vascular changes attributable to dysregulated HIF expression. An orthotopic tracheal transplantation model further evaluated the contribution of individual HIF isoforms in airway ECs.RESULTS: The genetic deletion of Hif-2alpha, but not Hif-1alpha, caused tracheal EC apoptosis, diminished pericyte coverage, reduced vascular perfusion, defective barrier function, overlying epithelial abnormalities and subepithelial fibrotic remodeling. HIF-2alpha promoted microvascular integrity in airways through endothelial angiopoietin-1/TIE2 signaling and Notch activity. In functional tracheal transplants, HIF-2alpha deficiency in airway donors accelerated graft microvascular loss, whereas HIF-2alpha or angiopoietin-1 overexpression prolonged transplant microvascular perfusion. Augmented endothelial HIF-2alpha in transplant donors promoted airway microvascular integrity and diminished alloimmune inflammation.CONCLUSIONS: Our findings reveal that the constitutive expression of endothelial HIF-2alpha is required for airway microvascular health.

  View details for PubMedID 30586708

• Dominant Role for Regulatory T Cells in Protecting Females Against Pulmonary Hypertension CIRCULATION RESEARCH Tamosiuniene, R., Manouvakhova, O., Mesange, P., Saito, T., Qian, J., Sanyal, M., Lin, Y., Nguyen, L. P., Luria, A., Tu, A. B., Sante, J. M., Rabinovitch, M., Fitzgerald, D. J., Graham, B. B., Habtezion, A., Voelkel, N. F., Aurelian, L., Nicolls, M. R. 2018; 122 (12): 1689-1702

  View details for DOI 10.1161/CIRCRESAHA.117.312058

  View details for Web of Science ID 000434652500011

• Circulating plasmablasts are elevated and produce pathogenic anti-endothelial cell autoantibodies in idiopathic pulmonary arterial hypertension EUROPEAN JOURNAL OF IMMUNOLOGY Blum, L. K., Cao, R. L., Sweatt, A. J., Bill, M., Lahey, L. J., Hsi, A. C., Lee, C. S., Kongpachith, S., Ju, C., Mao, R., Wong, H. H., Nicolls, M. R., Zamanian, R. T., Robinson, W. H. 2018; 48 (5): 874–84

  View details for DOI 10.1002/eji.201747460

  View details for Web of Science ID 000435725100016

• Circulating plasmablasts are elevated and produce pathogenic anti-endothelial cell autoantibodies in idiopathic pulmonary arterial hypertension. European journal of immunology Blum, L. K., Cao, R. R., Sweatt, A. J., Bill, M. n., Lahey, L. J., Hsi, A. C., Lee, C. S., Kongpachith, S. n., Ju, C. H., Mao, R. n., Wong, H. H., Nicolls, M. R., Zamanian, R. T., Robinson, W. H. 2018

  Abstract

  Idiopathic pulmonary arterial hypertension (IPAH) is a devastating pulmonary vascular disease in which autoimmune and inflammatory phenomena are implicated. B cells and autoantibodies have been associated with IPAH and identified as potential therapeutic targets. However, the specific populations of B cells involved and their roles in disease pathogenesis are not clearly defined. We aimed to assess the levels of activated B cells (plasmablasts) in IPAH, and to characterize recombinant antibodies derived from these plasmablasts. Blood plasmablasts are elevated in IPAH, remain elevated over time, and produce IgA autoantibodies. Single-cell sequencing of plasmablasts in IPAH revealed repertoires of affinity-matured antibodies with small clonal expansions, consistent with an ongoing autoimmune response. Recombinant antibodies representative of these clonal lineages bound known autoantigen targets and displayed an unexpectedly high degree of polyreactivity. Representative IPAH plasmablast recombinant antibodies stimulated human umbilical vein endothelial cells to produce cytokines and overexpress the adhesion molecule ICAM-1. Together, our results demonstrate an ongoing adaptive autoimmune response involving IgA plasmablasts that produce anti-endothelial cell autoantibodies in IPAH. These antibodies stimulate endothelial cell production of cytokines and adhesion molecules, which may contribute to disease pathogenesis. These findings suggest a role for mucosally-driven autoimmunity and autoimmune injury in the pathogenesis of IPAH. This article is protected by copyright. All rights reserved.

  View details for PubMedID 29369345

• Loss of Endothelial Derived WNT5A is Associated with Reduced Pericyte Recruitment and Small Vessel Loss in Pulmonary Arterial Hypertension. Circulation Yuan, K. n., Shamskhou, E. A., Orcholski, M. E., Nathan, A. n., Reddy, S. n., Honda, H. n., Mani, V. n., Zeng, Y. n., Ozen, M. O., Wang, L. n., Demirci, U. n., Tian, W. n., Nicolls, M. R., de Jesus Perez, V. A. 2018

  Abstract

  Pulmonary arterial hypertension (PAH) is a life-threatening disorder of the pulmonary circulation associated with loss and impaired regeneration of microvessels. Reduced pericyte coverage of pulmonary microvessels is a pathological feature of PAH and is partly due to the inability of pericytes to respond to signaling cues from neighboring pulmonary microvascular endothelial cells (PMVECs). We have shown that activation of the Wnt/PCP pathway is required for pericyte recruitment but whether production and release of specific Wnt ligands by PMVECs is responsible for Wnt/PCP activation in pericytes is unknown.Isolation of pericytes and PMVECs from healthy donor and PAH lungs was carried out using 3G5 or CD31 antibody conjugated magnetic beads. Wnt expression profile of PMVECs was documented via qPCR using a Wnt primer library. Exosome purification from PMVEC media was carried out using the ExoTIC device. Hemodynamic profile, right ventricular function and pulmonary vascular morphometry were obtained in a conditional endothelial specific Wnt5a knockout ( Wnt5aECKO) mouse model under normoxia, chronic hypoxia and hypoxia recovery.Quantification of Wnt ligand expression in healthy PMVECs co-cultured with pericytes demonstrated a 35-fold increase in Wnt5a, a known Wnt/PCP ligand. This Wnt5a spike was not seen in PAH PMVECs, which correlated with inability to recruit pericytes in matrigel co-culture assays. Exosomes purified from media demonstrated an increase in Wnt5a content when healthy PMVECs were co-cultured with pericytes, a finding that was not observed in exosomes of PAH PMVECs. Furthermore, the addition of either recombinant Wnt5a or purified healthy PMVEC exosomes increased pericyte recruitment to PAH PMVECs in co-culture studies. While no differences were noted in normoxia and chronic hypoxia, Wnt5aECKO mice demonstrated persistent pulmonary hypertension and right ventricular failure four weeks after recovery from chronic hypoxia, which correlated with significant reduction, muscularization and decreased pericyte coverage of microvessels.We identify Wnt5a as a key mediator for the establishment of pulmonary endothelial-pericyte interactions and its loss could contribute to PAH by reducing the viability of newly formed vessels. We speculate that therapies that mimic or restore Wnt5a production could help prevent loss of small vessels in PAH.

  View details for PubMedID 30586764

• Pilot studies demonstrate the potential benefits of antiinflammatory therapy in human lymphedema. JCI insight Rockson, S. G., Tian, W. n., Jiang, X. n., Kuznetsova, T. n., Haddad, F. n., Zampell, J. n., Mehrara, B. n., Sampson, J. P., Roche, L. n., Kim, J. n., Nicolls, M. R. 2018; 3 (20)

  Abstract

  Lymphedema is a common condition affecting millions around the world that still lacks approved medical therapy. Because ketoprofen, an NSAID, has been therapeutic in experimental lymphedema, we evaluated its efficacy in humans.We first performed an exploratory open-label trial. Patients with either primary or secondary lymphedema received ketoprofen 75 mg by mouth 3 times daily for 4 months. Subjects were evaluated for changes in histopathology, with skin thickness, limb volume, and tissue bioimpedance changes serving as secondary endpoints. Based on our encouraging findings, we next conducted a placebo-controlled trial, with the primary outcome defined as a change in skin thickness, as measured by skin calipers. Secondary endpoints for this second study included histopathology, limb volume, bioimpedance, and systemic inflammatory mediators.We enrolled 21 lymphedema patients in the open-label trial, from November 2010 to July 2011. Histopathology and skin thickness were significantly improved at 4 months compared with baseline. In the follow-up, double-blind, placebo-controlled trial, we enrolled 34 patients from August 2011 to October 2015, with 16 ketoprofen recipients and 18 placebo-treated subjects. No serious adverse events occurred. The ketoprofen recipients demonstrated reduced skin thickness, as well as improved composite measures of histopathology and decreased plasma granulocyte CSF (G-CSF) expression.These 2 exploratory studies together support the utility of targeted antiinflammatory therapy with ketoprofen in patients with lymphedema. Our results highlight the promise of such approaches to help restore a failing lymphatic circulation.ClinicalTrials.gov NCT02257970.

  View details for PubMedID 30333315

• Increased Lymphangiogenesis in Animal Models of Pulmonary Arterial Hypertension Zhang, P., Tian, A. W., Tu, A. B., Jiang, X., Nicolls, M. R. AMER THORACIC SOC. 2018

  View details for Web of Science ID 000449978904413

• Endothelial HIF-2 alpha Maintains Airway Microvasculature Through Angiopoietin-1/TIE2 Signaling Tu, A., Jiang, X., Tian, W., Nicolls, M. R. AMER THORACIC SOC. 2018

  View details for Web of Science ID 000449980300335

• The Role of Hypoxia Inducible Factors in Maintenance of Airway Epithelial Health Pasupneti, S., Tian, A., Jiang, X., Nicolls, M. R. AMER THORACIC SOC. 2018

  View details for Web of Science ID 000449978904464

• Pathology and pathobiology of pulmonary hypertension: state of the art and research perspectives. The European respiratory journal Humbert, M. n., Guignabert, C. n., Bonnet, S. n., Dorfmüller, P. n., Klinger, J. R., Nicolls, M. R., Olschewski, A. J., Pullamsetti, S. S., Schermuly, R. T., Stenmark, K. R., Rabinovitch, M. n. 2018

  Abstract

  Clinical and translational research has played a major role in advancing our understanding of pulmonary hypertension (PH), including pulmonary arterial hypertension and other forms of PH with severe vascular remodelling (e.g. chronic thromboembolic PH and pulmonary veno-occlusive disease). However, PH remains an incurable condition with a high mortality rate, underscoring the need for a better transfer of novel scientific knowledge into healthcare interventions. Herein, we review recent findings in pathology (with the questioning of the strict morphological categorisation of various forms of PH into pre- or post-capillary involvement of pulmonary vessels) and cellular mechanisms contributing to the onset and progression of pulmonary vascular remodelling associated with various forms of PH. We also discuss ways to improve management and to support and optimise drug development in this research field.

  View details for PubMedID 30545970

• A Pro - Con debate: Current Controversies in PAH Pathogenesis at the American Thoracic Society International Meeting in 2017. American journal of physiology. Lung cellular and molecular physiology Kuebler, W. M., Nicolls, M. R., Olschewski, A. n., Abe, K. n., Rabinovitch, M. n., Stewart, D. J., Chan, S. Y., Morrell, N. W., Archer, S. L., Spiekerkoetter, E. n. 2018

  Abstract

  The following review summarizes the pro-con debate about current controversies regarding the pathogenesis of pulmonary arterial hypertension (PAH) that took place at the American Thoracic Society Conference in May 2017. Leaders in the field of PAH research discussed the importance of the immune system, the role of hemodynamic stress and endothelial apoptosis as well as bone morphogenetic protein receptor 2 (BMPR2) signaling in PAH pathogenesis. While this summary does not intend to resolve obvious conflicts in opinion, we hope that the presented arguments entice further discussions and draw a new generation of enthusiastic researchers into this vibrant field of science to bridge existing gaps for a better understanding and therapy of this fatal disease.

  View details for PubMedID 29877097

• Microhemorrhage-associated tissue iron enhances the risk forAspergillus fumigatusinvasion in a mouse model of airway transplantation. Science translational medicine Hsu, J. L., Manouvakhova, O. V., Clemons, K. V., Inayathullah, M. n., Tu, A. B., Sobel, R. A., Tian, A. n., Nazik, H. n., Pothineni, V. R., Pasupneti, S. n., Jiang, X. n., Dhillon, G. S., Bedi, H. n., Rajadas, J. n., Haas, H. n., Aurelian, L. n., Stevens, D. A., Nicolls, M. R. 2018; 10 (429)

  Abstract

  Invasive pulmonary disease due to the moldAspergillus fumigatuscan be life-threatening in lung transplant recipients, but the risk factors remain poorly understood. To study this process, we used a tracheal allograft mouse model that recapitulates large airway changes observed in patients undergoing lung transplantation. We report that microhemorrhage-related iron content may be a major determinant ofA. fumigatusinvasion and, consequently, its virulence. Invasive growth was increased during progressive alloimmune-mediated graft rejection associated with high concentrations of ferric iron in the graft. The role of iron inA. fumigatusinvasive growth was further confirmed by showing that this invasive phenotype was increased in tracheal transplants from donor mice lacking the hemochromatosis gene (Hfe -/- ). The invasive phenotype was also increased in mouse syngrafts treated with topical iron solution and in allograft recipients receiving deferoxamine, a chelator that increases iron bioavailability to the mold. The invasive growth of the iron-intolerantA. fumigatusdouble-knockout mutant (ΔsreA/ΔcccA) was lower than that of the wild-type mold. Alloimmune-mediated microvascular damage and iron overload did not appear to impair the host's immune response. In human lung transplant recipients, positive staining for iron in lung transplant tissue was more commonly seen in endobronchial biopsy sections from transplanted airways than in biopsies from the patients' own airways. Collectively, these data identify iron as a major determinant ofA. fumigatusinvasive growth and a potential target to treat or preventA. fumigatusinfections in lung transplant patients.

  View details for PubMedID 29467298

• Nordihydroguaiaretic acid, a lignan from Larrea tridentata (Creosote bush) protects against ALIOS diet-induced metabolic dysfunction in mice. The Journal of pharmacology and experimental therapeutics Chan, J. K., Bittner, S. n., Bittner, A. n., Atwal, S. n., Shen, W. J., Inayathullah, M. n., Rajada, J. n., Nicolls, M. R., Kraemer, F. B., Azhar, S. n. 2018

  Abstract

  To determine the effects of NDGA on metabolic and molecular changes in response to feeding mice typical American fast food or Western diet, mice were fed with ALIOS diet and subjected to metabolic analysis. Male C57BL/6J mice were randomly assigned to: ALIOS, ALIOS + NDGA, or control diet and maintained on the specific diet for 8 weeks. Mice fed ALIOS diet, showed increased body, liver and epididymal fat pad weight, plasma ALT and AST levels (a measure of liver injury), and liver triglyceride (TG) content. Co-administration of NDGA normalized body and epididymal fat pad weight, ALT and AST levels, and liver TG. NDGA treatment also improved insulin sensitivity but not glucose intolerance in ALIOS diet fed mice. In ALIOS diet fed mice, NDGA supplementation induced PPARα (the master regulator of fatty acid oxidation) and mRNA levels of Cpt1c and Cpt2, key genes involved in fatty acid oxidation as compared to ALIOS diet. NDGA significantly reduced liver ER stress response CHOP protein, as compared to chow or ALIOS diet and also ameliorated ALIOS diet-induced elevation of apoptosis signaling protein, CASP3. Likewise, NDGA downregulated the ALIOS-diet induced mRNA levels of Pparg, Fasn, and Dgat2. NDGA treatment of ALIOS fed mice upregulated the hepatic expression of antioxidant enzymes, GPX4 and PRDX3 proteins. In conclusion, we provide evidence that NDGA improves metabolic dysregulation by simultaneously modulating PPARα transcription factor and key genes involved in fatty acid oxidation, key antioxidant and lipogenic enzymes, and apoptosis and ER stress signaling pathways.

  View details for PubMedID 29472517

• A Dominant Role for Regulatory T Cells in Protecting Females Against Pulmonary Hypertension. Circulation research Tamosiuniene, R. n., Manouvakhova, O. n., Mesange, P. n., Saito, T. n., Qian, J. n., Sanyal, M. n., Lin, Y. C., Nguyen, L. P., Luria, A. n., Tu, A. B., Sante, J. M., Rabinovitch, M. n., Fitzgerald, D. J., Graham, B. B., Habtezion, A. n., Voelkel, N. F., Aurelian, L. n., Nicolls, M. R. 2018

  Abstract

  Rationale: Pulmonary arterial hypertension (PH) is a life-threatening condition associated with immune dysregulation and abnormal regulatory T cell (Treg) activity, but it is currently unknown whether and how abnormal Treg function differentially affects males and females. Objective: To evaluate whether and how Treg-deficiency differentially affects male and female rats in experimental PH. Methods and Results: Male and female athymicrnu/rnurats, lacking Tregs, were treated with the vascular endothelial growth factor receptor-2 (VEGFR2) inhibitor SU5416 or chronic hypoxia and evaluated for PH; some animals underwent Treg immune reconstitution (IR) before SU5416 administration. Plasma prostacyclin (PGI2) levels were measured. Lung and right ventricles (RVs) were assessed for the expression of the vasoprotective proteins cyclooxygenase-2 (COX-2), prostacyclin synthase (PTGIS), programmed death ligand-1 (PDL-1), and heme oxygenase-1 (HO-1). Inhibitors of these pathways were administered to athymic rats undergoing Treg IR. Finally, human cardiac microvascular endothelial cells co-cultured with Tregs were evaluated for COX-2, PDL-1, HO-1, and estrogen receptor (ER) expression, and culture supernatants were assayed for PGI2 and IL-10. SU5416-treatment and chronic hypoxia produced more severe PH in female than male athymic rats. Females were distinguished by greater pulmonary inflammation, augmented RV fibrosis, lower plasma PGI2 levels, decreased lung COX-2, PTGIS, HO-1 and PDL-1 expression and reduced RV PDL-1 levels. In both sexes, Treg IR protected against PH development and raised levels of plasma PGI2 and cardiopulmonary COX-2, PTGIS, PDL-1, and HO-1. Inhibiting COX-2, HO-1, and programmed death-1 (PD1)/PDL1 pathways abrogated Treg protection. In vitro, human Tregs directly upregulated endothelial COX-2, PDL1, HO-1, ERs and increased supernatant levels of PGI2 and IL-10. Conclusions: In two animal models of PH based on Treg deficiency, females developed more severe PH than males. The data suggest that females are especially reliant on normal Treg function to counteract the effects of pulmonary vascular injury leading to PH.

  View details for PubMedID 29545367

• Dynamics of the human antibody repertoire after B cell depletion in systemic sclerosis. Science immunology de Bourcy, C. F., Dekker, C. L., Davis, M. M., Nicolls, M. R., Quake, S. R. 2017; 2 (15)

  Abstract

  Systemic sclerosis with pulmonary arterial hypertension (SSc-PAH) is a debilitating and frequently lethal disease of unknown cause lacking effective treatment options. Lymphocyte anomalies and autoantibodies observed in systemic sclerosis have suggested an autoimmune character. We study the clonal structure of the B cell repertoire in SSc-PAH using immunoglobulin heavy chain (IGH) sequencing before and after B cell depletion. We found SSc-PAH to be associated with anomalies in B cell development, namely, altered VDJ rearrangement frequencies (reduced IGHV2-5 segment usage) and an increased somatic mutation-fixation probability in expanded B cell lineages. SSc-PAH was also characterized by anomalies in B cell homeostasis, namely, an expanded immunoglobulin D-positive (IgD(+)) proportion with reduced mutation loads and an expanded proportion of highly antibody-secreting cells. Disease signatures pertaining to IGHV2-5 segment usage, IgD proportions, and mutation loads were temporarily reversed after B cell depletion. Analyzing the time course of B cell depletion, we find that the kinetics of naïve replenishment are predictable from baseline measurements alone, that release of plasma cells into the periphery can precede naïve replenishment, and that modes of B cell receptor diversity are highly elastic. Our findings reveal humoral immune signatures of SSc-PAH and uncover determinism in the effects of B cell depletion on the antibody repertoire.

  View details for DOI 10.1126/sciimmunol.aan8289

  View details for PubMedID 28963118

• Dynamics of the human antibody repertoire after B cell depletion in systemic sclerosis SCIENCE IMMUNOLOGY de Bourcy, C. A., Dekker, C. L., Davis, M. M., Nicolls, M. R., Quake, S. R. 2017; 2 (15)

  View details for DOI 10.1126/sciimiunol.aan8289

  View details for Web of Science ID 000434327200005

• The Roles of Immunity in the Prevention and Evolution of Pulmonary Arterial Hypertension AMERICAN JOURNAL OF RESPIRATORY AND CRITICAL CARE MEDICINE Nicolls, M. R., Voelkel, N. F. 2017; 195 (10): 1292-1299

  Abstract

  This Perspective provides an in depth overview of the many aspects of inflammation which are associated with many forms of severe pulmonary hypertension.Details of the pathobiology of severe pulmonary hypertension are discussed in the context of the multicellular inflammatory vascular infiltrates which represent a lung vessel response to injury and and a localized immune response.The important question whether inflammation is cause or consequence of pulmonary hypertension should not distract from designing and conducting clinical pilot studies which examine the efficacy of existing immune system modulating drugs.

  View details for DOI 10.1164/rccm.201608-1630PP

  View details for Web of Science ID 000401501400008

• Leukotriene B-4 antagonism ameliorates experimental lymphedema SCIENCE TRANSLATIONAL MEDICINE Tian, W., Rockson, S. G., Jiang, X., Kim, J., Begaye, A., Shuffle, E. M., Tu, A. B., Cribb, M., Nepiyushchikh, Z., Feroze, A. H., Zamanian, R. T., Dhillon, G. S., Voelkel, N. F., Peters-Golden, M., Kitajewski, J., Dixon, J. B., Nicolls, M. R. 2017; 9 (389)

  View details for DOI 10.1126/scitranslmed.aal3920

  View details for Web of Science ID 000400897600004

• Simultaneously Targeting Myofibroblast Contractility and Extracellular Matrix Cross-Linking as a Therapeutic Concept in Airway Fibrosis AMERICAN JOURNAL OF TRANSPLANTATION Lin, Y., Sung, Y. K., Jiang, X., Peters-Golden, M., Nicolls, M. R. 2017; 17 (5): 1229-1241

  Abstract

  Fibrosis after solid organ transplantation is considered an irreversible process and remains the major cause of graft dysfunction and death with limited therapies. This remodeling is characterized by aberrant accumulation of contractile myofibroblasts that deposit excessive extracellular matrix (ECM) and increase tissue stiffness. However, studies demonstrate that a stiff ECM, itself, promotes fibroblast-to-myofibroblast differentiation, stimulating further ECM production. This creates a positive feedback loop that perpetuates fibrosis. We hypothesized that simultaneously targeting myofibroblast contractility with relaxin and ECM stiffness with lysyl oxidase inhibitors could break the feedback loop, thereby, reversing established fibrosis. To test this, we used the orthotopic tracheal transplanted (OTT) mouse model, which develops robust fibrotic airway remodeling. Mice with established fibrosis were treated with saline, mono-, or combination therapies. While monotherapies had no effect, combining these agents decreased collagen deposition and promoted re-epithelialization of remodeled airways. Relaxin inhibited myofibroblast differentiation and contraction, in a matrix-stiffness-dependent manner through prostaglandin E2 (PGE2 ). Furthermore, the effect of combination therapy was lost in PGE2 receptor knockout and PGE2 inhibited OTT mice. This study reveals the important synergistic roles of cellular contractility and tissue stiffness in the maintenance of fibrotic tissue and suggests a new therapeutic principle for fibrosis. This article is protected by copyright. All rights reserved.

  View details for DOI 10.1111/ajt.14103

  View details for Web of Science ID 000400382300012

• Microvascular Integrity Can Be Preserved by Anti-Platelet Therapy and in Combination with mTOR Inhibitor Heim, C., Khan, M. A., Motsch, B., Gocht, A., Ramsperger-Gleixner, M., Stamminger, T., Nicolls, M. R., Weyand, M., Ensminger, S. M. ELSEVIER SCIENCE INC. 2017: S376

  View details for Web of Science ID 000398839801272

• Donor-Derived Cell-Free DNA Associates with Rejection in Lung Transplantation Using Clinical-Grade Targeted Next-Generation Sequencing Khush, K. K., Beausang, J. F., Woodward, R. N., Lew, D., Sninsky, J., De Vlaminck, I., Strehl, C., Luikart, H., Nicolls, M., Weill, D. ELSEVIER SCIENCE INC. 2017: S146

  View details for Web of Science ID 000398839800369

• Translating Research into Improved Patient Care in Pulmonary Arterial Hypertension AMERICAN JOURNAL OF RESPIRATORY AND CRITICAL CARE MEDICINE Bonnet, S., Provencher, S., Guignabert, C., Perros, F., Boucherat, O., Schermuly, R. T., Hassoun, P. M., Rabinovitch, M., Nicolls, M. R., Humbert, M. 2017; 195 (5): 583-595

  Abstract

  Despite important advances in its therapeutic management, pulmonary arterial hypertension (PAH) remains an incurable disease. Although numerous drugs exhibited beneficial effects in preclinical settings, only few have reached clinical trial phases, highlighting the challenges of translating preclinical investigations into clinical trials. Potential reasons for delayed PAH drug development may include the inherent limitations of the currently available animal and in vitro models, potential lack of appropriate standardization of the experimental design, regulatory agencies requirements, competing clinical trials and insufficient funding. Although this is not unique to PAH, there is urgency for reducing the number of false positive signals in preclinical studies and optimizing the development of innovative therapeutic targets through performance of clinical trials based on more robust experimental data. The current review discusses the challenges and opportunities in preclinical research to foster drug development in PAH.

  View details for DOI 10.1164/rccm.201607-1515PP

  View details for Web of Science ID 000395357400008

• Models of Lung Transplant Research: a consensus statement from the National Heart, Lung, and Blood Institute workshop. JCI insight Lama, V. N., Belperio, J. A., Christie, J. D., El-Chemaly, S. n., Fishbein, M. C., Gelman, A. E., Hancock, W. W., Keshavjee, S. n., Kreisel, D. n., Laubach, V. E., Looney, M. R., McDyer, J. F., Mohanakumar, T. n., Shilling, R. A., Panoskaltsis-Mortari, A. n., Wilkes, D. S., Eu, J. P., Nicolls, M. R. 2017; 2 (9)

  Abstract

  Lung transplantation, a cure for a number of end-stage lung diseases, continues to have the worst long-term outcomes when compared with other solid organ transplants. Preclinical modeling of the most common and serious lung transplantation complications are essential to better understand and mitigate the pathophysiological processes that lead to these complications. Various animal and in vitro models of lung transplant complications now exist and each of these models has unique strengths. However, significant issues, such as the required technical expertise as well as the robustness and clinical usefulness of these models, remain to be overcome or clarified. The National Heart, Lung, and Blood Institute (NHLBI) convened a workshop in March 2016 to review the state of preclinical science addressing the three most important complications of lung transplantation: primary graft dysfunction (PGD), acute rejection (AR), and chronic lung allograft dysfunction (CLAD). In addition, the participants of the workshop were tasked to make consensus recommendations on the best use of these complimentary models to close our knowledge gaps in PGD, AR, and CLAD. Their reviews and recommendations are summarized in this report. Furthermore, the participants outlined opportunities to collaborate and directions to accelerate research using these preclinical models.

  View details for PubMedID 28469087

• Hypoxia Inducible Factor-1 alpha Increases Bone Morphogenetic Protein Receptor 2 Signaling In Pulmonary Artery Endothelial Cells (paecs) Kuang, J., Tian, X., Prosseda, S., Tian, A., Cornfield, D., Nicolls, M. R., Spiekerkoetter, E. F. AMER THORACIC SOC. 2017

  View details for Web of Science ID 000400372501417

• Dynamics of the human antibody repertoire after B cell depletion in systemic sclerosis Dynamics of the human antibody repertoire after B cell depletion in systemic sclerosis de Bourcy, C. F., Dekker, C. L., Davis, M. M., Nicolls, M. R., Quake, S. R. 2017; 2 (15)

  View details for DOI 10.1126/sciimmunol.aan8289

• Leukotriene B4 Potentiates Bmpr2 Deficiency And Causes Paec Endmt In Pah Tian, A., Jiang, X., Shuffle, E., Tu, A., Jin, Q., Zamanian, R. T., Voelkel, N., Peters-Golden, M., Tuder, R., Rabinovitch, M., Nicolls, M. AMER THORACIC SOC. 2017

  View details for Web of Science ID 000400372501405

• Delivery Of Il-10 Using A Novel High Molecular Weight Hyaluronan Vehicle Reduces Lung Fibrosis In A Bleomycin Mouse Model Of Lung Injury Shamskhou, E., Orcholski, M., Kaber, G., Yuan, K., Danielson, B., Chapman, H., Nicolls, M., Bollyky, P., Perez, V. AMER THORACIC SOC. 2017

  View details for Web of Science ID 000400372504775

• Clinical Heterogeneity Across Proteomic Immunophenotypes In Pulmonary Arterial Hypertension Sweatt, A., Hedlin, H., Balasubramanian, V., Hsi, A., Blum, L., Robinson, W., Nicolls, M., Rabinovitch, M., Khatri, P., Zamanian, R. T. AMER THORACIC SOC. 2017

  View details for Web of Science ID 000400372507579

• Discovery Of Proteomic Immune Signatures In Pulmonary Arterial Hypertension By Unsupervised Consensus Clustering Sweatt, A., Hedlin, H., Balasubramanian, V., Hsi, A., Blum, L., Robinson, W., Nicolls, M. R., Rabinovitch, M., Khatri, P., Zamanian, R. T. AMER THORACIC SOC. 2017

  View details for Web of Science ID 000400372507578

• Upregulation of HERV-K is Linked to Immunity and Inflammation in Pulmonary Arterial Hypertension. Circulation Saito, T. n., Miyagawa, K. n., Chen, S. Y., Tamosiuniene, R. n., Wang, L. n., Sharp, O. n., Samayoa, E. n., Harada, D. n., Moonen, J. A., Cao, A. n., Chen, P. I., Hennigs, J. K., Gu, M. n., Li, C. G., Leib, R. D., Li, D. n., Adams, C. M., Del Rosario, P. A., Bill, M. A., Haddad, F. n., Montoya, J. G., Robinson, W. n., Fantl, W. J., Nolan, G. P., Zamanian, R. T., Nicolls, M. R., Chiu, C. Y., Ariza, M. E., Rabinovitch, M. n. 2017

  Abstract

  Background -Immune dysregulation has been linked to occlusive vascular remodeling in pulmonary arterial hypertension (PAH) that is hereditary, idiopathic or associated with other conditions. Circulating autoantibodies, lung perivascular lymphoid tissue and elevated cytokines have been related to PAH pathogenesis but without clear understanding of how these abnormalities are initiated, perpetuated and connected in the progression of disease. We therefore set out to identify specific target antigens in PAH lung immune complexes as a starting point toward resolving these issues to better inform future application of immunomodulatory therapies. Methods -Lung immune complexes were isolated and PAH target antigens were identified by liquid chromatography tandem mass spectrometry (LCMS), confirmed by ELISA, and localized by confocal microscopy. One PAH antigen linked to immunity and inflammation was pursued and a link to PAH pathophysiology was investigated by next generation sequencing, functional studies in cultured monocytes and endothelial cells (EC) and hemodynamic and lung studies in a rat. Results -SAM domain and HD1 domain-containing protein (SAMHD1), an innate immune factor that suppresses HIV replication was identified and confirmed as highly expressed in immune complexes from 16 hereditary and idiopathic PAH vs. 12 control lungs. Elevated SAMHD1 was localized to endothelial cells (EC), perivascular dendritic cells and macrophages and SAMHD1 antibodies were prevalent in tertiary lymphoid tissue. An unbiased screen using metagenomic sequencing related SAMHD1 to increased expression of human endogenous retrovirus K (HERV-K) in PAH vs. control lungs (n=4 each). HERV-K envelope and deoxyuridine triphosphate nucleotidohydrolase (dUTPase) mRNAs were elevated in PAH vs. control lungs (n=10) and proteins were localized to macrophages. HERV-K dUTPase induced SAMHD1 and pro-inflammatory cytokines (e.g., IL6, IL1β and TNFα) in circulating monocytes and pulmonary arterial (PA) EC, and activated B cells. Vulnerability of PAEC to apoptosis was increased by HERV-K dUTPase in an IL6 independent manner. Furthermore, three weekly injections of HERV-K dUTPase induced hemodynamic and vascular changes of pulmonary hypertension in rats (n=8), and elevated IL6. Conclusions -Our study reveals that upregulation of the endogenous retrovirus HERV-K could both initiate and sustain activation of the immune system and cause vascular changes associated with PAH.

  View details for PubMedID 28935667

• Lymphatic Dysfunction, Leukotrienes, and Lymphedema. Annual review of physiology Jiang, X. n., Nicolls, M. R., Tian, W. n., Rockson, S. G. 2017

  Abstract

  The lymphatic system is essential for the maintenance of tissue fluid homeostasis, gastrointestinal lipid absorption, and immune trafficking. Whereas lymphatic regeneration occurs physiologically in wound healing and tissue repair, pathological lymphangiogenesis has been implicated in a number of chronic diseases such as lymphedema, atherosclerosis, and cancer. Insight into the regulatory mechanisms of lymphangiogenesis and the manner in which uncontrolled inflammation promotes lymphatic dysfunction is urgently needed to guide the development of novel therapeutics: These would be designed to reverse lymphatic dysfunction, either primary or acquired. Recent investigation has demonstrated the mechanistic role of leukotriene B4 (LTB4) in the molecular pathogenesis of lymphedema. LTB4, a product of the innate immune response, is a constituent of the eicosanoid inflammatory mediator family of molecules that promote both physiological and pathological inflammation. Here we provide an overview of lymphatic development, the pathophysiology of lymphedema, and the role of leukotrienes in lymphedema pathogenesis. Expected final online publication date for the Annual Review of Physiology Volume 80 is February 10, 2018. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

  View details for PubMedID 29029593

• Introduction to the 59th Annual Thomas L. Petty Aspen Lung Conference. Lung Transplantation: Opportunities for Repair and Regeneration. Annals of the American Thoracic Society Zamora, M. R., Martinu, T. n., Nicolls, M. R. 2017; 14 (Supplement_3): S209

  View details for PubMedID 28945478

• Aspergillus-related pulmonary diseases in lung transplantation MEDICAL MYCOLOGY Pasupneti, S., Manouvakhova, O., Nicolls, M. R., Hsu, J. L. 2017; 55 (1): 96-102

  Abstract

  While lung transplantation is an attractive treatment option for many end stage lung diseases, the relatively high 5-year mortality continues to be a significant limiting factor. Among the foremost reasons for this is the eventual development of obstructive chronic lung allograft dysfunction. Infections, which the lung allograft is especially prone to, are a major risk factor. Specifically, the Aspergillus species cause a higher burden of disease among lung transplant recipients, due to unique risk factors, such as relative hypoxemia. However, these risk factors also provide unique opportunities for treatment and preventative strategies, as outlined in this review.

  View details for DOI 10.1093/mmy/myw121

  View details for Web of Science ID 000393896500013

• Simultaneously Targeting Myofibroblast Contractility and Extracellular Matrix Cross-Linking as a Therapeutic Concept in Airway Fibrosis. American journal of transplantation Lin, Y., Sung, Y. K., Jiang, X., Peters-Golden, M., Nicolls, M. R. 2016

  Abstract

  Fibrosis after solid organ transplantation is considered an irreversible process and remains the major cause of graft dysfunction and death with limited therapies. This remodeling is characterized by aberrant accumulation of contractile myofibroblasts that deposit excessive extracellular matrix (ECM) and increase tissue stiffness. However, studies demonstrate that a stiff ECM, itself, promotes fibroblast-to-myofibroblast differentiation, stimulating further ECM production. This creates a positive feedback loop that perpetuates fibrosis. We hypothesized that simultaneously targeting myofibroblast contractility with relaxin and ECM stiffness with lysyl oxidase inhibitors could break the feedback loop, thereby, reversing established fibrosis. To test this, we used the orthotopic tracheal transplanted (OTT) mouse model, which develops robust fibrotic airway remodeling. Mice with established fibrosis were treated with saline, mono-, or combination therapies. While monotherapies had no effect, combining these agents decreased collagen deposition and promoted re-epithelialization of remodeled airways. Relaxin inhibited myofibroblast differentiation and contraction, in a matrix-stiffness-dependent manner through prostaglandin E2 (PGE2 ). Furthermore, the effect of combination therapy was lost in PGE2 receptor knockout and PGE2 inhibited OTT mice. This study reveals the important synergistic roles of cellular contractility and tissue stiffness in the maintenance of fibrotic tissue and suggests a new therapeutic principle for fibrosis. This article is protected by copyright. All rights reserved.

  View details for DOI 10.1111/ajt.14103

  View details for PubMedID 27804215

• Enhanced Electrochemical Sensing with Carbon Nanotubes Modified with Bismuth and Magnetic Nanoparticles in a Lab-on-a-Chip. ChemNanoMat : chemistry of nanomaterials for energy, biology and more Jothimuthu, P., Hsu, J. L., Chen, R., Inayathullah, M., Pothineni, V. R., Jan, A., Gurtner, G. C., Rajadas, J., Nicolls, M. R. 2016; 2 (9): 904-910

  Abstract

  Iron plays an especially important role in human physiological functions and pathological impairments. The superior properties of carbon nanotubes (CNTs) and their modification with bismuth and magnetic nanoparticles as developed in this work have led to an extraordinary and novel material to facilitate ultrasensitive detection in the nanomolar range. Here, we present the development of an electrochemical sensor for detection of ferrous (Fe(2+)) and ferric (Fe(3+)) iron by means of CNTs modified with bismuth and magnetic nanoparticles for higher sensitivity of detection. The sensor fabrication includes microfabrication methodologies, soft lithography, and electrodeposition. Cyclic voltammetry and differential pulse voltammetry are used for the electroanalytical studies and detection of the ions in samples. The sensor has a dynamic range of detection from 0.01 nm to 10 mm. The performance of the sensor with modified CNTs was explored for sensitivity and specificity. CNTs, modified with bismuth and magnetic nanoparticles by means of electrodeposition, enhanced the detection limit significantly down to 0.01 nm.

  View details for DOI 10.1002/cnma.201600174

  View details for PubMedID 27857882

  View details for PubMedCentralID PMC5110256

• Enhanced Electrochemical Sensing with Carbon Nanotubes Modified with Bismuth and Magnetic Nanoparticles in a Lab-on-a-Chip CHEMNANOMAT Jothimuthu, P., Hsu, J. L., Chen, R., Inayathullah, M., Pothineni, V. R., Jan, A., Gurtner, G. C., Rajadas, J., Nicolls, M. R. 2016; 2 (9): 904-910

  Abstract

  Iron plays an especially important role in human physiological functions and pathological impairments. The superior properties of carbon nanotubes (CNTs) and their modification with bismuth and magnetic nanoparticles as developed in this work have led to an extraordinary and novel material to facilitate ultrasensitive detection in the nanomolar range. Here, we present the development of an electrochemical sensor for detection of ferrous (Fe(2+)) and ferric (Fe(3+)) iron by means of CNTs modified with bismuth and magnetic nanoparticles for higher sensitivity of detection. The sensor fabrication includes microfabrication methodologies, soft lithography, and electrodeposition. Cyclic voltammetry and differential pulse voltammetry are used for the electroanalytical studies and detection of the ions in samples. The sensor has a dynamic range of detection from 0.01 nm to 10 mm. The performance of the sensor with modified CNTs was explored for sensitivity and specificity. CNTs, modified with bismuth and magnetic nanoparticles by means of electrodeposition, enhanced the detection limit significantly down to 0.01 nm.

  View details for DOI 10.1002/cnma.201600174

  View details for Web of Science ID 000383766800009

  View details for PubMedCentralID PMC5110256

• Challenges and opportunities in treating inflammation associated with pulmonary hypertension. Expert review of cardiovascular therapy Voelkel, N. F., Tamosiuniene, R., Nicolls, M. R. 2016; 14 (8): 939-951

  Abstract

  Inflammatory cells are present in the lungs from patients with many, if not all, forms of severe pulmonary hypertension. Historically the first inflammatory cell identified in the pulmonary vascular lesions was the mast cell. T and B lymphocytes, as well as macrophages, are present in and around the pulmonary arterioles and many patients have elevated blood levels of interleukin 1 and 6; some patients show elevated levels of leukotriene B4. An overlap between collagen-vascular disease-associated pulmonary arterial hypertension (PAH) and idiopathic PAH exists, yet only a few studies have been designed that evaluate the effect of anti-inflammatory treatments. Here we review the pertinent data that connect PAH and inflammation/immune dysregulation and evaluate experimental models of severe PAH with an emphasis on the Sugen/athymic rat model of severe PAH. We postulate that there are more than one inflammatory phenotype and predict that there will be several anti-inflammatory treatment strategies for severe PAH.

  View details for DOI 10.1080/14779072.2016.1180976

  View details for PubMedID 27096622

• Effect of Transplant Center Volume on Cost and Readmissions in Medicare Lung Transplant Recipients. Annals of the American Thoracic Society Mooney, J. J., Weill, D., Boyd, J. H., Nicolls, M. R., Bhattacharya, J., Dhillon, G. S. 2016; 13 (7): 1034-1041

  Abstract

  While lung transplant recipient survival is better at higher volume centers, the effect of center volume on admission cost and early hospital readmission is unknown.To understand the association between transplant center volume and recipient risk-adjusted transplant admission cost, in-hospital mortality, and early hospital readmission in lung transplant recipients.Medicare lung transplant recipients from May 4, 2005 to December 31, 2011 were identified through linkage of transplant registry and Medicare administrative claims. Transplant admission cost was extracted, adjusted for regional price variation, and compared across low, intermediate, and high volume centers. A multivariable hierarchical generalized linear regression model was used to assess the effect of transplant center volume on recipient adjusted cost. Modified Poisson regression models were used to assess adjusted in-hospital mortality and early hospital readmission by transplant center volume.There were 3,128 Medicare lung transplant recipients identified. Unadjusted transplant cost was lower at high volume centers (mean $131,352, SD±$106,165; median $90,177, IQR $79,165-$137,915) than intermediate (mean $138,792, SD±$106,270; median $93,024, IQR $82,700-$154,857) or low volume (mean $143,609, SD±$123,316; median $95,234, IQR $83,052-$152,149) centers (p<0.0001). After adjusting for recipient health risk, low volume centers had an 11.66% greater transplant admission cost (p=0.040), a 41% greater risk for in-hospital mortality (p=0.015), and a 14% greater risk for early hospital readmission (p=0.033) compared to high volume centers. There was no significant difference in transplant cost, in-hospital mortality, or early hospital readmission between intermediate and high volume centers.Lung transplant admission cost, in-hospital mortality, and early hospital readmission rate are lower at high volume centers compared to low volume centers.

  View details for DOI 10.1513/AnnalsATS.201601-017OC

  View details for PubMedID 27064753

• Microvascular injury after lung transplantation CURRENT OPINION IN ORGAN TRANSPLANTATION Nicolls, M. R., Hsu, J. L., Jiang, X. 2016; 21 (3): 279-284

  Abstract

  Airway microvessel injury following transplantation has been implicated in the development of chronic rejection. This review focuses on the most recent developments in the field describing preclinical and clinical findings that further implicate the loss of microvascular integrity as an important pathological event in the evolution of irreversible fibrotic remodeling.When lungs are transplanted, the airways appear vulnerable from the perspective of perfusion. Two vascular systems are lost, the bronchial artery and the lymphatic circulations, and the remaining vasculature in the airways expresses donor antigens susceptible to alloimmune-mediated injury via innate and adaptive immune mechanisms. Preclinical studies indicate the importance of hypoxia-inducible factor-1α in mediating microvascular repair and that hypoxia-inducible factor-1α can be upregulated to bolster endogenous repair.Airway microvascular injury is a feature of lung transplantation that limits short-term and long-term organ health. Although some problems are attributable to a missing bronchial artery circulation, another significant issue involves alloimmune-mediated injury to transplant airway microvessels. For a variety of reasons, bronchial artery revascularization surgery at the time of transplantation has not been widely adopted, and the current best hope for this era may be new medical approaches that offer protection against immune-mediated vascular injury or that promote microvascular repair.

  View details for DOI 10.1097/MOT.0000000000000307

  View details for Web of Science ID 000376015500007

  View details for PubMedID 26967995

• Lung Quality and Utilization in Controlled Donation After Circulatory Determination of Death Within the United States AMERICAN JOURNAL OF TRANSPLANTATION Mooney, J. J., Hedlin, H., Mohabir, P. K., Vazquez, R., Nguyen, J., Ha, R., Chiu, P., Patel, K., Zamora, M. R., Weill, D., Nicolls, M. R., Dhillon, G. S. 2016; 16 (4): 1207-1215

  Abstract

  Although controlled donation after circulatory determination of death (cDCDD) could increase the supply of donor lungs within the United States, the yield of lungs from cDCDD donors remains low compared with donation after neurologic determination of death (DNDD). To explore the reason for low lung yield from cDCDD donors, Scientific Registry of Transplant Recipient data were used to assess the impact of donor lung quality on cDCDD lung utilization by fitting a logistic regression model. The relationship between center volume and cDCDD use was assessed, and the distance between center and donor hospital was calculated by cDCDD status. Recipient survival was compared using a multivariable Cox regression model. Lung utilization was 2.1% for cDCDD donors and 21.4% for DNDD donors. Being a cDCDD donor decreased lung donation (adjusted odds ratio 0.101, 95% confidence interval [CI] 0.085-0.120). A minority of centers have performed cDCDD transplant, with higher volume centers generally performing more cDCDD transplants. There was no difference in center-to-donor distance or recipient survival (adjusted hazard ratio 1.03, 95% CI 0.78-1.37) between cDCDD and DNDD transplants. cDCDD lungs are underutilized compared with DNDD lungs after adjusting for lung quality. Increasing transplant center expertise and commitment to cDCDD lung procurement is needed to improve utilization.

  View details for DOI 10.1111/ajt.13599

  View details for Web of Science ID 000373075400021

• A Critical Role for Airway Microvessels in Lung Transplantation. American journal of respiratory and critical care medicine Nicolls, M. R., Dhillon, G. S., Daddi, N. 2016; 193 (5): 479-481

  View details for DOI 10.1164/rccm.201511-2117ED

  View details for PubMedID 26930430

• Lung Quality and Utilization in Controlled Donation After Circulatory Determination of Death Within the United States. American journal of transplantation : official journal of the American Society of Transplantation and the American Society of Transplant Surgeons Mooney, J. J., Hedlin, H., Mohabir, P. K., Vazquez, R., Nguyen, J., Ha, R., Chiu, P., Patel, K., Zamora, M. R., Weill, D., Nicolls, M. R., Dhillon, G. S. 2016

  Abstract

  Although controlled donation after circulatory determination of death (cDCDD) could increase the supply of donor lungs within the United States, the yield of lungs from cDCDD donors remains low compared with donation after neurologic determination of death (DNDD). To explore the reason for low lung yield from cDCDD donors, Scientific Registry of Transplant Recipient data were used to assess the impact of donor lung quality on cDCDD lung utilization by fitting a logistic regression model. The relationship between center volume and cDCDD use was assessed, and the distance between center and donor hospital was calculated by cDCDD status. Recipient survival was compared using a multivariable Cox regression model. Lung utilization was 2.1% for cDCDD donors and 21.4% for DNDD donors. Being a cDCDD donor decreased lung donation (adjusted odds ratio 0.101, 95% confidence interval [CI] 0.085-0.120). A minority of centers have performed cDCDD transplant, with higher volume centers generally performing more cDCDD transplants. There was no difference in center-to-donor distance or recipient survival (adjusted hazard ratio 1.03, 95% CI 0.78-1.37) between cDCDD and DNDD transplants. cDCDD lungs are underutilized compared with DNDD lungs after adjusting for lung quality. Increasing transplant center expertise and commitment to cDCDD lung procurement is needed to improve utilization.

  View details for DOI 10.1111/ajt.13599

  View details for PubMedID 26844673

• Limitations Of Pulmonary Vascular Resistance As A Primary Endpoint For Therapeutic Trials Of Systemic Sclerosis Associated Pulmonary Arterial Hypertension Zamanian, R. T., Rhee, R., Pinckney, A., Goldmuntz, E., Welch, B., D'Aveta, C., Badesch, D., Nicolls, M., Kawut, S. M., Spychala, M., Autoimmunity Ctr Excellence ASC01 AMER THORACIC SOC. 2016

  View details for Web of Science ID 000390749607302

• Impact Of Non Invasive Open Ventilation (niov) On Dyspnea And Quality Of Life In Patients With Chronic Obstructive Pulmonary Disease (COPD) And Idiopathic Pulmonary Fibrosis (ipf) Breiburg, A., Lam, K., Dhillon, G., Zone, C., Nicolls, M., Kuschner, W. AMER THORACIC SOC. 2016

  View details for Web of Science ID 000390749606652

• Circulating Elastase Confers A High Risk For The Development Of Bronchiolitis Obliterans Syndrome Milla, C. E., Zirbes, J. M., Yacob, A., Tian, L., Zamanian, R. T., Bental-Roof, M., Bland, R., Rabinovitch, M., Dhillon, G., Nicolls, M. AMER THORACIC SOC. 2016

  View details for Web of Science ID 000390749604185

• Bmpr2 Deficiency Potentiates The Ltb4 Mediated Paec Transformation In Pah Tian, W., Jiang, X., Qian, J., Tu, A., Shuffle, E., Mesange, P., Nicolls, M. AMER THORACIC SOC. 2016

  View details for Web of Science ID 000390749601390

• Inhibition Of Connective Tissue Growth Factor Promotes Healthy Revascularization And Ameliorates Fibrosis In Orthotopic Tracheal Transplantation Lin, Y., Jiang, X., Nicolls, M. AMER THORACIC SOC. 2016

  View details for Web of Science ID 000390749602712

• Acute Microvascular Rejection Increases Graft Iron, Promoting Aspergillus Fumigatus Allograft Invasion Hsu, J. L., Inayathulla, M., Tu, A. B., Clemons, K. V., Rajadas, J., Stevens, D. A., Nicolls, M. AMER THORACIC SOC. 2016

  View details for Web of Science ID 000390749604400

• Endothelial Hif-2a Deficiency Disrupts Airway Microvascular Structure And Impairs The Repair Of Vessels Of Transplanted Airways Jiang, X., Tian, W., Tu, A., Nicolls, M. AMER THORACIC SOC. 2016

  View details for Web of Science ID 000390749604396

• Leukotriene B-4 Activates Pulmonary Artery Adventitial Fibroblasts in Pulmonary Hypertension HYPERTENSION Qian, J., Tian, W., Jiang, X., Tamosiuniene, R., Sung, Y. K., Shuffle, E. M., Tu, A. B., Valenzuela, A., Jiang, S., Zamanian, R. T., Fiorentino, D. F., Voelkel, N. F., Peters-Golden, M., Stenmark, K. R., Chung, L., Rabinovitch, M., Nicolls, M. R. 2015; 66 (6): 1227-1239

  Abstract

  A recent study demonstrated a significant role for leukotriene B4 (LTB4) causing pulmonary vascular remodeling in pulmonary arterial hypertension. LTB4 was found to directly injure luminal endothelial cells and promote growth of the smooth muscle cell layer of pulmonary arterioles. The purpose of this study was to determine the effects of LTB4 on the pulmonary adventitial layer, largely composed of fibroblasts. Here, we demonstrate that LTB4 enhanced human pulmonary artery adventitial fibroblast proliferation, migration, and differentiation in a dose-dependent manner through its cognate G-protein-coupled receptor, BLT1. LTB4 activated human pulmonary artery adventitial fibroblast by upregulating p38 mitogen-activated protein kinase as well as Nox4-signaling pathways. In an autoimmune model of pulmonary hypertension, inhibition of these pathways blocked perivascular inflammation, decreased Nox4 expression, reduced reactive oxygen species production, reversed arteriolar adventitial fibroblast activation, and attenuated pulmonary hypertension development. This study uncovers a novel mechanism by which LTB4 further promotes pulmonary arterial hypertension pathogenesis, beyond its established effects on endothelial and smooth muscle cells, by activating adventitial fibroblasts.

  View details for DOI 10.1161/HYPERTENSIONAHA.115.06370

  View details for PubMedID 26558820

• Noninvasive monitoring of infection and rejection after lung transplantation. Proceedings of the National Academy of Sciences of the United States of America De Vlaminck, I., Martin, L., Kertesz, M., Patel, K., Kowarsky, M., Strehl, C., Cohen, G., Luikart, H., Neff, N. F., Okamoto, J., Nicolls, M. R., Cornfield, D., Weill, D., Valantine, H., Khush, K. K., Quake, S. R. 2015; 112 (43): 13336-13341

  Abstract

  The survival rate following lung transplantation is among the lowest of all solid-organ transplants, and current diagnostic tests often fail to distinguish between infection and rejection, the two primary posttransplant clinical complications. We describe a diagnostic assay that simultaneously monitors for rejection and infection in lung transplant recipients by sequencing of cell-free DNA (cfDNA) in plasma. We determined that the levels of donor-derived cfDNA directly correlate with the results of invasive tests of rejection (area under the curve 0.9). We also analyzed the nonhuman cfDNA as a hypothesis-free approach to test for infections. Cytomegalovirus is most frequently assayed clinically, and the levels of CMV-derived sequences in cfDNA are consistent with clinical results. We furthermore show that hypothesis-free monitoring for pathogens using cfDNA reveals undiagnosed cases of infection, and that certain infectious pathogens such as human herpesvirus (HHV) 6, HHV-7, and adenovirus, which are not often tested clinically, occur with high frequency in this cohort.

  View details for DOI 10.1073/pnas.1517494112

  View details for PubMedID 26460048

• Cyclosporine Does Not Prevent Microvascular Loss in Transplantation but Can Synergize With a Neutrophil Elastase Inhibitor, Elafin, to Maintain Graft Perfusion During Acute Rejection AMERICAN JOURNAL OF TRANSPLANTATION Jiang, X., Nguyen, T. T., Tian, W., Sung, Y. K., Yuan, K., Qian, J., Rajadas, J., Sallenave, J., Nickel, N. P., Perez, V. d., RABINOVITCH, M., Nicolls, M. R. 2015; 15 (7): 1768-1781

  Abstract

  The loss of a functional microvascular bed in rejecting solid organ transplants is correlated with fibrotic remodeling and chronic rejection; in lung allografts, this pathology is predicted by bronchoalveolar fluid neutrophilia which suggests a role for polymorphonuclear cells in microcirculatory injury. In a mouse orthotopic tracheal transplant model, cyclosporine, which primarily inhibits T cells, failed as a monotherapy for preventing microvessel rejection and graft ischemia. To target neutrophil action that may be contributing to vascular injury, we examined the effect of a neutrophil elastase inhibitor, elafin, on the microvascular health of transplant tissue. We showed that elafin monotherapy prolonged microvascular perfusion and enhanced tissue oxygenation while diminishing the infiltration of neutrophils and macrophages and decreasing tissue deposition of complement C3 and the membrane attack complex, C5b-9. Elafin was also found to promote angiogenesis through activation of the extracellular signal-regulated kinase (ERK) signaling pathway but was insufficient as a single agent to completely prevent tissue ischemia during acute rejection episodes. However, when combined with cyclosporine, elafin effectively preserved airway microvascular perfusion and oxygenation. The therapeutic strategy of targeting neutrophil elastase activity alongside standard immunosuppression during acute rejection episodes may be an effective approach for preventing the development of irreversible fibrotic remodeling.

  View details for DOI 10.1111/ajt.13189

  View details for Web of Science ID 000356494300013

  View details for PubMedID 25727073

• Elafin Reverses Pulmonary Hypertension via Caveolin-1-Dependent Bone Morphogenetic Protein Signaling AMERICAN JOURNAL OF RESPIRATORY AND CRITICAL CARE MEDICINE Nickel, N. P., Spiekerkoetter, E., Gu, M., Li, C. G., Li, H., Kaschwich, M., Diebold, I., Hennigs, J. K., Kim, K., Miyagawa, K., Wang, L., Cao, A., Sa, S., Jiang, X., Stockstill, R. W., Nicolls, M. R., Zamanian, R. T., Bland, R. D., Rabinovitch, M. 2015; 191 (11): 1273-1286

  Abstract

  Pulmonary arterial hypertension is characterized by endothelial cell dysfunction, impaired BMPR2 signaling, and increased elastase activity. Synthetic elastase inhibitors reverse experimental pulmonary hypertension but cause hepatotoxicity in clinical studies. The endogenous elastase inhibitor elafin attenuates the development of hypoxic pulmonary hypertension in mice, but its potential to improve endothelial cell function and BMPR2 signaling, and to reverse severe experimental pulmonary hypertension or vascular pathology in the human disease was unknown.To assess elafin-mediated regression of pulmonary vascular pathology in rats with pulmonary hypertension induced by VEGF receptor blockade and hypoxia (Sugen/Hypoxia), and in lung explants from pulmonary hypertension patients. To determine if elafin amplifies BMPR2 signaling in pulmonary artery endothelial cells from controls and patients, and to elucidate the underlying mechanism. Methods, Measurements and Main Results: In Sugen/Hypoxia rats, elafin reduced elastase activity and reversed pulmonary hypertension, judged by regression of right ventricular systolic pressure and hypertrophy and pulmonary artery occlusive changes. Elafin improved endothelial function by increasing apelin, a product of BMPR2 signaling. Elafin induced apoptosis in human pulmonary arterial smooth muscle cells and in lung organ culture elafin decreased neointimal lesions. In normal and patient pulmonary artery endothelial cells, elafin enhanced survival and promoted angiogenesis by increasing pSMAD dependent and independent BMPR2 signaling. This was linked mechanistically to augmented interaction of BMPR2 with caveolin-1 via elafin-mediated stabilization of caveolin-1 on endothelial surfaces.Elafin reverses obliterative changes in rat and human pulmonary arteries via elastase inhibition and caveolin-1 dependent amplification of BMPR2 signaling.

  View details for DOI 10.1164/rccm.201412-2291OC

  View details for Web of Science ID 000356105000014

  View details for PubMedID 25853696

• Non-Invasive Monitoring of Infection and Rejection After Lung Transplantation Vlaminck, I. D., Martin, L., Kertesz, M., Patel, K. N., Kowarsky, M., Strehl, C., Cohen, G., Luikart, H., Neff, N., Okamoto, J., Nicolls, M. N., Cornfield, D. N., Weill, D., Valantine, H. A., Khush, K. K., Quake, S. R. ELSEVIER SCIENCE INC. 2015: S137

  View details for DOI 10.1016/j.healun.2015.01.368

  View details for Web of Science ID 000353251500348

• Increased Resource Use in Lung Transplant Admissions in the Lung Allocation Score Era AMERICAN JOURNAL OF RESPIRATORY AND CRITICAL CARE MEDICINE Maxwelll, B. G., Mooney, J. J., Lee, P. H., Levitt, J. E., Chhatwani, L., Nicolls, M. R., Zamora, M. R., Valentine, V., Weill, D., Dhillon, G. S. 2015; 191 (3): 302-308

  Abstract

  Rationale: In 2005, the lung allocation score (LAS) was implemented to prioritize organ allocation to minimize waiting-list mortality and maximize one-year survival. It resulted in transplantation of older and sicker patients without changing one-year survival. Its effect on resource utilization is unknown. Objective: To determine changes in resource utilization over time in lung transplant admissions Methods: Solid organ transplant recipients were identified within the Nationwide Inpatient Sample (NIS) data from 2000 to 2011. Joinpoint regression methodology was performed to identify a time point of change in mean total hospital charges amongst lung transplant and other solid organ transplant recipients. Two temporal lung transplant recipient cohorts identified by joinpoint regression were compared for baseline characteristics and resource utilization, including total charges for index hospitalization, charges per day, length of stay, discharge disposition, tracheostomy, and need for extracorporeal membrane oxygenation (ECMO). Measurements and Main Results: A significant point of increased total hospital charges occurred for lung transplant recipients in 2005, corresponding to LAS implementation, that was not seen in other solid organ transplant recipients. Total transplant hospital charges increased by 40% in the post-LAS cohort [$569,942 ($53,229) vs. $407,489 ($28,360)] along with an increased median length of stay, daily charges, and discharge disposition other than to home. Post-LAS recipients also had higher post-transplant utilization of ECMO (OR 2.35, 95% CI 1.56, 3.55) and higher incidence of tracheostomy (OR 1.52, 95% CI 1.22, 1.89). Conclusions: LAS implementation is associated with a significant increase in resource utilization during index hospitalization for lung transplant.

  View details for DOI 10.1164/rccm.201408-1562OC

  View details for Web of Science ID 000348827000014

  View details for PubMedID 25517213

• Activation of the Wnt/Planar Cell Polarity Pathway Is Required for Pericyte Recruitment during Pulmonary Angiogenesis. American journal of pathology Yuan, K., Orcholski, M. E., Panaroni, C., Shuffle, E. M., Huang, N. F., Jiang, X., Tian, W., Vladar, E. K., Wang, L., Nicolls, M. R., Wu, J. Y., de Jesus Perez, V. A. 2015; 185 (1): 69-84

  Abstract

  Pericytes are perivascular cells localized to capillaries that promote vessel maturation, and their absence can contribute to vessel loss. Whether impaired endothelial-pericyte interaction contributes to small vessel loss in pulmonary arterial hypertension (PAH) is unclear. Using 3G5-specific, immunoglobulin G-coated magnetic beads, we isolated pericytes from the lungs of healthy subjects and PAH patients, followed by lineage validation. PAH pericytes seeded with healthy pulmonary microvascular endothelial cells failed to associate with endothelial tubes, resulting in smaller vascular networks compared to those with healthy pericytes. After the demonstration of abnormal polarization toward endothelium via live-imaging and wound-healing studies, we screened PAH pericytes for abnormalities in the Wnt/planar cell polarity (PCP) pathway, which has been shown to regulate cell motility and polarity in the pulmonary vasculature. PAH pericytes had reduced expression of frizzled 7 (Fzd7) and cdc42, genes crucial for Wnt/PCP activation. With simultaneous knockdown of Fzd7 and cdc42 in healthy pericytes in vitro and in a murine model of angiogenesis, motility and polarization toward pulmonary microvascular endothelial cells were reduced, whereas with restoration of both genes in PAH pericytes, endothelial-pericyte association was improved, with larger vascular networks. These studies suggest that the motility and polarity of pericytes during pulmonary angiogenesis are regulated by Wnt/PCP activation, which can be targeted to prevent vessel loss in PAH.

  View details for DOI 10.1016/j.ajpath.2014.09.013

  View details for PubMedID 25447046

• Hypoxia Inducible Factor-1 alpha Increases Bone Morphogenetic Protein Signaling In Pulmonary Artery Endothelial Cells Kuang, J., Tian, X., Tian, A., Semenza, G., Nicolls, M. R., Spiekerkoetter, E. AMER THORACIC SOC. 2015

  View details for Web of Science ID 000377582801328

• Activation of the Wnt/Planar Cell Polarity Pathway Is Required for Pericyte Recruitment during Pulmonary Angiogenesis AMERICAN JOURNAL OF PATHOLOGY Yuan, K., Orcholski, M. E., Panaroni, C., Shuffle, E. M., Huang, N. F., Jiang, X., Tian, W., Vladar, E. K., Wang, L., Nicolls, M. R., Wu, J. Y., Perez, V. A. 2015; 185 (1): 69-84

  Abstract

  Pericytes are perivascular cells localized to capillaries that promote vessel maturation, and their absence can contribute to vessel loss. Whether impaired endothelial-pericyte interaction contributes to small vessel loss in pulmonary arterial hypertension (PAH) is unclear. Using 3G5-specific, immunoglobulin G-coated magnetic beads, we isolated pericytes from the lungs of healthy subjects and PAH patients, followed by lineage validation. PAH pericytes seeded with healthy pulmonary microvascular endothelial cells failed to associate with endothelial tubes, resulting in smaller vascular networks compared to those with healthy pericytes. After the demonstration of abnormal polarization toward endothelium via live-imaging and wound-healing studies, we screened PAH pericytes for abnormalities in the Wnt/planar cell polarity (PCP) pathway, which has been shown to regulate cell motility and polarity in the pulmonary vasculature. PAH pericytes had reduced expression of frizzled 7 (Fzd7) and cdc42, genes crucial for Wnt/PCP activation. With simultaneous knockdown of Fzd7 and cdc42 in healthy pericytes in vitro and in a murine model of angiogenesis, motility and polarization toward pulmonary microvascular endothelial cells were reduced, whereas with restoration of both genes in PAH pericytes, endothelial-pericyte association was improved, with larger vascular networks. These studies suggest that the motility and polarity of pericytes during pulmonary angiogenesis are regulated by Wnt/PCP activation, which can be targeted to prevent vessel loss in PAH.

  View details for DOI 10.1016/j.ajpath.2014.09.013

  View details for Web of Science ID 000346887200008

• Unique predictors of mortality in patients with pulmonary arterial hypertension associated with systemic sclerosis in the REVEAL registry. Chest Chung, L., Farber, H. W., Benza, R., Miller, D. P., Parsons, L., Hassoun, P. M., McGoon, M., Nicolls, M. R., Zamanian, R. T. 2014; 146 (6): 1494-1504

  Abstract

  Background:Patients with pulmonary arterial hypertension associated with systemic sclerosis (SSc-APAH) experience higher mortality rates than patients with idiopathic disease and those with other connective tissue diseases (CTD-APAH). We sought to identify unique predictors of mortality associated with SSc-APAH in the CTD-APAH population. Methods:The Registry to Evaluate Early and Long-Term PAH Management (REVEAL) is a multicenter, prospective US-based registry of patients with previously and newly diagnosed (enrollment within 90 days of diagnostic right heart catheterization) PAH. Cox regression models evaluated all previously identified candidate predictors of mortality in the overall REVEAL population to identify significant predictors of mortality in the SSc-APAH (n=500) versus non-SSc-CTD-APAH (n=304) populations. Results:Three-year survival in the previously diagnosed and newly diagnosed SSc-APAH group was 61.4±2.7% and 51.2±4.0%, respectively, compared with 80.9±2.7% and 76.4±4.6%, respectively, in the non-SSc-CTD-APAH group (P<.001). In multivariate analyses, males aged >60 years, systolic blood pressure (SBP) ≤110 mmHg, 6-minute walk distance (6MWD) <165 m, mean right atrial pressure (mRAP) >20 mmHg within 1 year, and pulmonary vascular resistance (PVR) >32 WU remained unique predictors of mortality in the SSc-APAH group; 6MWD ≥440 m was protective in the non-SSc-CTD-APAH group, but not the SSc-APAH group. Conclusions:Patients with SSc-APAH have higher mortality rates than non-SSc-CTD-APAH patients. Identifying SSc-APAH patients who are at particularly high risk of death, including elderly males and patients with low baseline SBP or 6MWD, or markedly elevated mRAP or PVR, will enable clinicians to identify patients who may benefit from closer monitoring and more aggressive treatment. Registered at:www.clinicaltrials.gov #NCT00370214.Patients with pulmonary arterial hypertension associated with systemic sclerosis (SSc-APAH) experience higher mortality rates than patients with idiopathic disease and those with other connective tissue diseases (CTD-APAH). We sought to identify unique predictors of mortality associated with SSc-APAH in the CTD-APAH population.The Registry to Evaluate Early and Long-Term PAH Management (REVEAL) is a multicenter, prospective US-based registry of patients with previously and newly diagnosed (enrollment within 90 days of diagnostic right heart catheterization) PAH. Cox regression models evaluated all previously identified candidate predictors of mortality in the overall REVEAL population to identify significant predictors of mortality in the SSc-APAH (n=500) versus non-SSc-CTD-APAH (n=304) populations.Three-year survival in the previously diagnosed and newly diagnosed SSc-APAH group was 61.4±2.7% and 51.2±4.0%, respectively, compared with 80.9±2.7% and 76.4±4.6%, respectively, in the non-SSc-CTD-APAH group (P<.001). In multivariate analyses, males aged >60 years, systolic blood pressure (SBP) ≤110 mmHg, 6-minute walk distance (6MWD) <165 m, mean right atrial pressure (mRAP) >20 mmHg within 1 year, and pulmonary vascular resistance (PVR) >32 WU remained unique predictors of mortality in the SSc-APAH group; 6MWD ≥440 m was protective in the non-SSc-CTD-APAH group, but not the SSc-APAH group.Patients with SSc-APAH have higher mortality rates than non-SSc-CTD-APAH patients. Identifying SSc-APAH patients who are at particularly high risk of death, including elderly males and patients with low baseline SBP or 6MWD, or markedly elevated mRAP or PVR, will enable clinicians to identify patients who may benefit from closer monitoring and more aggressive treatment.www.clinicaltrials.gov #NCT00370214.

  View details for DOI 10.1378/chest.13-3014

  View details for PubMedID 24992469

• Impact of the lung allocation score on survival beyond 1 year. American journal of transplantation Maxwell, B. G., Levitt, J. E., Goldstein, B. A., Mooney, J. J., Nicolls, M. R., Zamora, M., Valentine, V., Weill, D., Dhillon, G. S. 2014; 14 (10): 2288-2294

  Abstract

  Implementation of the lung allocation score (LAS) in 2005 led to transplantation of older and sicker patients without altering 1-year survival. However, long-term survival has not been assessed and emphasizing the 1-year survival metric may actually sustain 1-year survival while not reflecting worsening longer-term survival. Therefore, we assessed overall and conditional 1-year survival; and the effect of crossing the 1-year threshold on hazard of death in three temporal cohorts: historical (1995-2000), pre-LAS (2001-2005) and post-LAS (2005-2010). One-year survival post-LAS remained similar to pre-LAS (83.1% vs. 82.1%) and better than historical controls (75%). Overall survival in the pre- and post-LAS cohorts was also similar. However, long-term survival among patients surviving beyond 1 year was worse than pre-LAS and similar to historical controls. Also, the hazard of death increased significantly in months 13 (1.44, 95% CI 1.10-1.87) and 14 (1.43, 95% CI 1.09-1.87) post-LAS but not in the other cohorts. While implementation of the LAS has not reduced overall survival, decreased survival among patients surviving beyond 1 year in the post-LAS cohort and the increased mortality occurring immediately after 1 year suggest a potential negative long-term effect of the LAS and an unintended consequence of increased emphasis on the 1-year survival metric.

  View details for DOI 10.1111/ajt.12903

  View details for PubMedID 25208599

• CLOPIDOGREL PRESERVES MICROVASCULAR VASCULAR INTEGRITY IN ORTHOTOPIC TRACHEAL TRANSPLANTS AFFECTED BY OBLITERATIVE BRONCHIOLITIS Heim, C., Khan, M. A., Motsch, B., Mueller, S., Stamminger, T., Nicolls, M. R., Weyand, M., Ensminger, S. WILEY-BLACKWELL. 2014: 11

  View details for Web of Science ID 000342752400026

• Impact of the Lung Allocation Score on Survival Beyond 1 Year AMERICAN JOURNAL OF TRANSPLANTATION Maxwell, B. G., Levitt, J. E., Goldstein, B. A., Mooney, J. J., Nicolls, M. R., Zamora, M., Valentine, V., Weill, D., Dhillon, G. S. 2014; 14 (10): 2288-2294

  Abstract

  Implementation of the lung allocation score (LAS) in 2005 led to transplantation of older and sicker patients without altering 1-year survival. However, long-term survival has not been assessed and emphasizing the 1-year survival metric may actually sustain 1-year survival while not reflecting worsening longer-term survival. Therefore, we assessed overall and conditional 1-year survival; and the effect of crossing the 1-year threshold on hazard of death in three temporal cohorts: historical (1995-2000), pre-LAS (2001-2005) and post-LAS (2005-2010). One-year survival post-LAS remained similar to pre-LAS (83.1% vs. 82.1%) and better than historical controls (75%). Overall survival in the pre- and post-LAS cohorts was also similar. However, long-term survival among patients surviving beyond 1 year was worse than pre-LAS and similar to historical controls. Also, the hazard of death increased significantly in months 13 (1.44, 95% CI 1.10-1.87) and 14 (1.43, 95% CI 1.09-1.87) post-LAS but not in the other cohorts. While implementation of the LAS has not reduced overall survival, decreased survival among patients surviving beyond 1 year in the post-LAS cohort and the increased mortality occurring immediately after 1 year suggest a potential negative long-term effect of the LAS and an unintended consequence of increased emphasis on the 1-year survival metric.

  View details for DOI 10.1111/ajt.12903

  View details for Web of Science ID 000342663300014

• Nuclear Factor ?B Inhibition Reduces Lung Vascular Lumen Obliteration in Severe Pulmonary Hypertension in Rats. American journal of respiratory cell and molecular biology Farkas, D., Alhussaini, A. A., Kraskauskas, D., Kraskauskiene, V., Cool, C. D., Nicolls, M. R., Natarajan, R., Farkas, L. 2014; 51 (3): 413-425

  Abstract

  Nuclear factor-κB (NF-κB) and interleukin-6 (IL-6), a NF-κB downstream mediator, play a central role in the inflammatory response of tissues. We aimed to determine the role of the classical NF-κB pathway in severe pulmonary arterial hypertension (PAH) induced by SU5416 and chronic hypoxia (SuHx) in rats. Tissue samples from patients with idiopathic PAH (iPAH) and control subjects were investigated. SuHx rats were treated from days 1-3, 1-21 and 29-42 with the NF-κB inhibitor pyrrolidine dithiocarbamate (PDTC) and/or from days 1-21 with anti-IL-6 antibody. Nuclear staining for NF-κB, an indicator of the activation of the classical NF-κB pathway, was detected in pulmonary arterial lesions of iPAH patients and SuHx rats. NF-κB inhibition with PDTC prevented and reduced pulmonary arterial obliteration without reducing muscularization. However, the elevated lung levels of IL-6 were not reduced in PDTC-treated SuHx animals. PDTC treatment prevented or reduced apoptosis of pulmonary artery wall cells and pulmonary arterial obliteration. IL-6 inhibition had only a partial effect on apoptosis and obliteration. Pulmonary arterial media wall thickness was not affected by any of these treatments. Preventive and therapeutic PDTC treatment promoted immune regulation by increasing the number of perivascular CD4+ T cells, in particular regulatory T cells (early treatment) and by reducing the number of perivascular CD8+ T lymphocytes and CD45RA+ B lymphocytes. Therapeutic PDTC treatment further preserved right ventricular function in SuHx animals. Inhibition of NF-κB may represent a therapeutic option for pulmonary arterial obliteration via reduced vessel wall cell apoptosis and improved regulation of the immune system.

  View details for DOI 10.1165/rcmb.2013-0355OC

  View details for PubMedID 24684441

• Graft microvascular disease in solid organ transplantation. Journal of molecular medicine (Berlin, Germany) Jiang, X., Sung, Y. K., Tian, W., Qian, J., Semenza, G. L., Nicolls, M. R. 2014; 92 (8): 797-810

  Abstract

  Alloimmune inflammation damages the microvasculature of solid organ transplants during acute rejection. Although immunosuppressive drugs diminish the inflammatory response, they do not directly promote vascular repair. Repetitive microvascular injury with insufficient regeneration results in prolonged tissue hypoxia and fibrotic remodeling. While clinical studies show that a loss of the microvascular circulation precedes and may act as an initiating factor for the development of chronic rejection, preclinical studies demonstrate that improved microvascular perfusion during acute rejection delays and attenuates tissue fibrosis. Therefore, preservation of a functional microvasculature may represent an effective therapeutic strategy for preventing chronic rejection. Here, we review recent advances in our understanding of the role of the microvasculature in the long-term survival of transplanted solid organs. We also highlight microvessel-centered therapeutic strategies for prolonging the survival of solid organ transplants.

  View details for DOI 10.1007/s00109-014-1173-y

  View details for PubMedID 24880953

• Relaxin Increases Cellular Softening Which Synergizes With ECM-Softening LOX Inhibitor to Attenuates Airway Fibrosis in Mouse Orthotopic Tracheal Transplantation Lin, Y., Jiang, X., Nicolls, M. LIPPINCOTT WILLIAMS & WILKINS. 2014: 400

  View details for Web of Science ID 000339104602276

• Clopidogrel Preserves Microvascular Integrity in Orthotopic Tracheal Transplants Affected By Obliterative Bronchiolitis. Heim, C., Khan, M., Motsch, B., Mueller, S., Stamminger, T., Nicolls, M., Weyand, M., Ensminger, S. LIPPINCOTT WILLIAMS & WILKINS. 2014: 327

  View details for Web of Science ID 000339104602001

• Hypoxia Inducible Factor-1 alpha Limits Aspergillus fumigatus Invasion in the Rejecting Airway Allograft. Hsu, J., Jiang, X., Clemons, K., Stevens, D., Nicolls, M. LIPPINCOTT WILLIAMS & WILKINS. 2014: 270

  View details for Web of Science ID 000339104601356

• Inflammation and Immunity in the Pathogenesis of Pulmonary Arterial Hypertension CIRCULATION RESEARCH Rabinovitch, M., Guignabert, C., Humbert, M., Nicolls, M. R. 2014; 115 (1): 165-175

  Abstract

  This review summarizes an expanding body of knowledge indicating that failure to resolve inflammation and altered immune processes underlie the development of pulmonary arterial hypertension. The chemokines and cytokines implicated in pulmonary arterial hypertension that could form a biomarker platform are discussed. Pre-clinical studies that provide the basis for dysregulated immunity in animal models of the disease are reviewed. In addition, we present therapies that target inflammatory/immune mechanisms that are currently enrolling patients, and discuss others in development. We show how genetic and metabolic abnormalities are inextricably linked to dysregulated immunity and adverse remodeling in the pulmonary arteries.

  View details for DOI 10.1161/CIRCRESAHA.113.301141

  View details for Web of Science ID 000337738900018

  View details for PubMedID 24951765

• Clopidogrel Preserves Microvascular Integrity in Orthotopic Tracheal Transplants Affected By Obliterative Bronchiolitis Heim, C., Khan, M., Motsch, B., Mueller, S., Stamminger, T., Nicolls, M., Weyand, M., Ensminger, S. WILEY-BLACKWELL. 2014: 327

  View details for Web of Science ID 000338033301394

• Hypoxia Inducible Factor-1 alpha Limits Aspergillus fumigatus Invasion in the Rejecting Airway Allograft. Hsu, J., Jiang, X., Clemons, K., Stevens, D., Nicolls, M. WILEY-BLACKWELL. 2014: 270

  View details for Web of Science ID 000338033301179

• Relaxin Increases Cellular Softening Which Synergizes With ECM-Softening LOX Inhibitor to Attenuates Airway Fibrosis in Mouse Orthotopic Tracheal Transplantation Lin, Y., Jiang, X., Nicolls, M. WILEY-BLACKWELL. 2014: 400

  View details for Web of Science ID 000338033301669

• Leukotrienes in pulmonary arterial hypertension. Immunologic research Tian, W., Jiang, X., Sung, Y. K., Qian, J., Yuan, K., Nicolls, M. R. 2014; 58 (2-3): 387-393

  Abstract

  Leukotrienes (LTs) are lipid mediators derived from the 5-lipoxygenase (5-LO) pathway of arachidonic acid metabolism and are markers and mediators of pulmonary inflammation. Research over the past two decades has established that LTs modulate inflammation in pulmonary arterial hypertension (PAH). The purpose of this review was to summarize the current knowledge of LTs in the pathophysiology of PAH and to highlight a recent study that advances our understanding of how leukotriene B4 (LTB4) specifically contributes to pulmonary vascular remodeling. The results of these studies suggest that pharmacological inhibition of LT pathways, especially LTB4, has high potential for the treatment of PAH.

  View details for DOI 10.1007/s12026-014-8492-5

  View details for PubMedID 24570092

• Complement components as potential therapeutic targets for asthma treatment RESPIRATORY MEDICINE Khan, M. A., Nicolls, M. R., Surguladze, B., Saadoun, I. 2014; 108 (4): 543-549

  Abstract

  Asthma is the most common respiratory disorder, and is characterized by distal airway inflammation and hyperresponsiveness. This disease challenges human health because of its increasing prevalence, severity, morbidity, and the lack of a proper and complete cure. Asthma is characterized by TH2-skewed inflammation with elevated pulmonary levels of IL-4, IL-5, and IL-13 levels. Although there are early forays into targeting TH2 immunity, less-specific corticosteroid therapy remains the immunomodulator of choice. Innate immune injury mediated by complement components also act as potent mediators of the allergic inflammatory responses and offer a new and exciting possibility for asthma immunotherapy. The complement cascade consists of a number of plasma- and membrane-bound proteins, and the cleavage products of these proteins (C3 and C5) regulate the magnitude of adaptive immune responses. Complement protein are responsible for many pathophysiological features of asthma, including inflammatory cell infiltration, mucus secretion, increases in vascular permeability, and smooth muscle cell contraction. This review highlights the complement-mediated injury during asthma inflammation, and how blockade of active complement mediators may have therapeutic application.

  View details for DOI 10.1016/j.rmed.2014.01.005

  View details for Web of Science ID 000333856400001

  View details for PubMedID 24468195

• Clopidogrel Preserves Microvascular Integrity in Orthotopic Tracheal Transplants affected by Obliterative Bronchiolitis Heim, C., Khan, M. A., Motsch, B., Mueller, S., Ramsperger-Gleixner, M., Stamminger, T., Nicolls, M. R., Weyand, M., Ensminger, S. ELSEVIER SCIENCE INC. 2014: S255

  View details for DOI 10.1016/j.healun.2014.01.668

  View details for Web of Science ID 000333866700691

• Efficacy of Transthoracic Echocardiography for Diagnosing Heart Failure in Septic Shock AMERICAN JOURNAL OF THE MEDICAL SCIENCES Beraud, A., Guillamet, C. V., Hammes, J. L., Meng, L., Nicolls, M. R., Hsu, J. L. 2014; 347 (4): 295-298

  Abstract

  Cardiac dysfunction occurs in up to 80% of patients with septic shock. Transthoracic echocardiography (TTE) is an ideal tool for the detailed characterization of cardiac function. Its feasibility is perceived to be poor in critically ill patients, but this has never been studied. To address this question, the authors evaluated the efficacy of TTE to diagnose heart failure in septic shock.This was a retrospective study. Patients admitted to the intensive care unit with septic shock and who had a TTE within 72 hours of intensive care unit admission were identified by a computer algorithm and validated by chart review. Echocardiography images were reviewed by a single cardiologist blinded to clinical outcomes. Clinical information was collected from patients' medical record.Seventy-six patients met the studies' inclusion criteria. The feasibility of TTE to calculate left ventricular ejection fraction was 90% and to assess diastolic function was 74%. Significant mitral regurgitation or aortic stenosis was the most frequent impediments for the assessment of diastolic function. Seventy-four percent of all patients showed some type of cardiac dysfunction (left or right ventricular systolic dysfunction and/or left ventricular diastolic dysfunction). In regression analyses, TTE feasibility was not impacted by factors previously associated with poor image acquisition: high body mass index, mechanical ventilation, tachycardia, advanced age or high severity of illness.This study demonstrated that TTE is a useful tool to assess myocardial function in critically ill patients and suggested its potential to assist in the management of patients with septic shock.

  View details for DOI 10.1097/MAJ.0b013e318297d616

  View details for Web of Science ID 000335788700008

  View details for PubMedID 24051955

• Application of a non-amplification-based technology to detect invasive fungal pathogens DIAGNOSTIC MICROBIOLOGY AND INFECTIOUS DISEASE Hsu, J. L., Binkley, J., Clemons, K. V., Stevens, D. A., Nicolls, M. R., Holodniy, M. 2014; 78 (2): 137-140

  Abstract

  Current diagnostic techniques for fungal diseases could be improved with respect to sensitivity, specificity, and timeliness. To address this clinical need, we adapted a non-amplification-based nucleic acid detection technology to identify fungal pathogens. We demonstrate a high-specificity, detection sensitivity, reproducibility, and multiplex capacity for detecting fungal strains.

  View details for DOI 10.1016/j.diagmicrobio.2013.11.013

  View details for Web of Science ID 000330149700007

  View details for PubMedID 24359934

• Working toward immune tolerance in lung transplantation. The Journal of clinical investigation Jiang, X. n., Nicolls, M. R. 2014: 1–4

  Abstract

  Long-term allograft survival is a major challenge facing solid organ transplantation. Recent studies have shown a negative correlation between infiltration of memory T cells and allograft survival. Furthermore, blockade of leukocyte activation increases acceptance of transplanted organs, including heart, liver, and kidney. Lung allografts are associated with high rates of rejection, and therapies that increase acceptance of other transplanted organs have not translated into the lung. In this issue of the JCI, Krupnick and colleagues demonstrate in a murine model that lung allograft acceptance requires infiltration of a specific T cell population into the graft. This study highlights the unique immunobiology of the lung and the complexity of lung transplant tolerance.

  View details for DOI 10.1172/JCI74701

  View details for PubMedID 24569371

• Inhibition Of Nf-kappa b Improves Immune Regulation In The Su5416 And Chronic Hypoxia Model Of Severe Obliterative Pah Farkas, D., Kraskauskas, D., Kraskauskiene, V., Voelkel, N. F., Fowler, A. A., Natarajan, R., Nicolls, M. R., Farkas, L. AMER THORACIC SOC. 2014

  View details for Web of Science ID 000209838202623

• Novel Risk Score Prediction Using Inflammatory Cytokines In Pulmonary Arterial Hypertension Selej, M., Tian, L., Scalfone, L., Lawrie, A., Nicolls, M. R., Robinson, W., Rabinovitch, M., Zamanian, R. T. AMER THORACIC SOC. 2014

  View details for Web of Science ID 000209838206436

• Traumatic Brain Injury: Lungs in a RAGE. Science translational medicine Nicolls, M. R., Laubach, V. E. 2014; 6 (252): 252fs34

  Abstract

  Individuals who die of traumatic brain injury show damage to the lungs mediated by the HMGB1-RAGE axis, which renders the lungs suboptimal for transplantation (Weber et al.).

  View details for PubMedID 25186173

• Macrophages in solid organ transplantation. Vascular cell Jiang, X., Tian, W., Sung, Y. K., Qian, J., Nicolls, M. R. 2014; 6 (1): 5-?

  Abstract

  Macrophages are highly plastic hematopoietic cells with diversified functions related to their anatomic location and differentiation states. A number of recent studies have examined the role of macrophages in solid organ transplantation. These studies show that macrophages can induce allograft injury but, conversely, can also promote tissue repair in ischemia-reperfusion injury and acute rejection. Therapeutic strategies that target macrophages to improve outcomes in solid organ transplant recipients are being examined in preclinical and clinical models. In this review, we discuss the role of macrophages in different types of injury and rejection, with a focus on macrophage-mediated tissue injury, specifically vascular injury, repair and remodeling. We also discuss emerging macrophage-centered therapeutic opportunities in solid organ transplantation.

  View details for DOI 10.1186/2045-824X-6-5

  View details for PubMedID 24612731

• Promotion of airway anastomotic microvascular regeneration and alleviation of airway ischemia by deferoxamine nanoparticles. Biomaterials Jiang, X., Malkovskiy, A. V., Tian, W., Sung, Y. K., Sun, W., Hsu, J. L., Manickam, S., Wagh, D., Joubert, L., Semenza, G. L., Rajadas, J., Nicolls, M. R. 2014; 35 (2): 803-813

  Abstract

  Airway tissue ischemia and hypoxia in human lung transplantation is a consequence of the sacrifice of the bronchial circulation during the surgical procedure and is a major risk factor for the development of airway anastomotic complications. Augmented expression of hypoxia-inducible factor (HIF)-1α promotes microvascular repair and alleviates allograft ischemia and hypoxia. Deferoxamine mesylate (DFO) is an FDA-approved iron chelator which has been shown to upregulate cellular HIF-1α. Here, we developed a nanoparticle formulation of DFO that can be topically applied to airway transplants at the time of surgery. In a mouse orthotopic tracheal transplant (OTT) model, the DFO nanoparticle was highly effective in enhancing airway microvascular perfusion following transplantation through the production of the angiogenic factors, placental growth factor (PLGF) and stromal cell-derived factor (SDF)-1. The endothelial cells in DFO treated airways displayed higher levels of p-eNOS and Ki67, less apoptosis, and decreased production of perivascular reactive oxygen species (ROS) compared to vehicle-treated airways. In summary, a DFO formulation topically-applied at the time of surgery successfully augmented airway anastomotic microvascular regeneration and the repair of alloimmune-injured microvasculature. This approach may be an effective topical transplant-conditioning therapy for preventing airway complications following clinical lung transplantation.

  View details for DOI 10.1016/j.biomaterials.2013.09.092

  View details for PubMedID 24161166

• The Critical Role of mRNA Destabilizing Protein Heterogeneous Nuclear Ribonucleoprotein D in 3 ' Untranslated Region-Mediated Decay of Low-Density Lipoprotein Receptor mRNA in Liver Tissue ARTERIOSCLEROSIS THROMBOSIS AND VASCULAR BIOLOGY Singh, A. B., Li, H., Kan, C. F., Dong, B., Nicolls, M. R., Liu, J. 2014; 34 (1): 8-?

  Abstract

  Previous studies showed that low-density lipoprotein receptor (LDLR) mRNA 3' untranslated region (UTR) contains regulatory elements responsible for rapid mRNA turnover in hepatic cells and mediates the mRNA stabilization induced by berberine (BBR). Here, we elucidate the underlying mechanism of BBR's action by characterizing mRNA-binding proteins that modulate LDLR mRNA decay via 3'UTR in liver tissue in vivo.We generated a transgenic mouse model (Alb-Luc-UTR) that expresses Luc-LDLR3'UTR reporter gene driven by the albumin promoter to study 3'UTR function in mediating LDLR mRNA decay in liver tissue. We show that treating Alb-Luc-UTR mice with BBR led to significant increases in hepatic bioluminescence signals, Luc-UTR mRNA, and LDLR mRNA levels as compared with control mice. These effects were accompanied by specific reductions of mRNA decay-promoting factor heterogeneous nuclear ribonucleoprotein D (hnRNP D) in liver of BBR-treated mice. Knockdown and overexpression studies further demonstrated that hnRNP D p37 isoform plays a major role in promoting hepatic LDLR mRNA degradation. In addition, we examined LDLR mRNA half-life, Luc-UTR reporter activity, and hnRNP D expression levels in cell lines derived from extrahepatic tissues. We demonstrated that strengths of 3'UTR in promoting mRNA degradation correlate with hnRNP D cellular abundances in nonhepatic cell lines, thereby suggesting its involvement in LDLR mRNA degradation beyond liver tissue.hnRNP D is critically involved in LDLR mRNA degradation in liver tissue in vivo. The inverse relationship of hnRNP D abundance with LDLR mRNA levels after BBR treatment suggests the potential of hnRNP D of being a novel therapeutic target for LDL cholesterol lowering.

  View details for DOI 10.1161/ATVBAHA.112.301131

  View details for Web of Science ID 000337731100005

  View details for PubMedID 24158514

• Nf-?B Inhibition Prevents Vascular Obliteration and Improves Immune Regulation in Severe Pulmonary Arterial Hypertension Farkas, D., Alhussaini, A. A., Kraskauskas, D., Kraskauskiene, V., Nicolls, M. R., Voelkel, N. F., Natarajan, R., Farkas, L. LIPPINCOTT WILLIAMS & WILKINS. 2013

  View details for Web of Science ID 000332162900428

• Temporal response of the human virome to immunosuppression and antiviral therapy. Cell De Vlaminck, I., Khush, K. K., Strehl, C., Kohli, B., Luikart, H., Neff, N. F., Okamoto, J., Snyder, T. M., Cornfield, D. N., Nicolls, M. R., Weill, D., Bernstein, D., Valantine, H. A., Quake, S. R. 2013; 155 (5): 1178-1187

  Abstract

  There are few substantive methods to measure the health of the immune system, and the connection between immune strength and the viral component of the microbiome is poorly understood. Organ transplant recipients are treated with posttransplant therapies that combine immunosuppressive and antiviral drugs, offering a window into the effects of immune modulation on the virome. We used sequencing of cell-free DNA in plasma to investigate drug-virome interactions in a cohort of organ transplant recipients (656 samples, 96 patients) and find that antivirals and immunosuppressants strongly affect the structure of the virome in plasma. We observe marked virome compositional dynamics at the onset of the therapy and find that the total viral load increases with immunosuppression, whereas the bacterial component of the microbiome remains largely unaffected. The data provide insight into the relationship between the human virome, the state of the immune system, and the effects of pharmacological treatment and offer a potential application of the virome state to predict immunocompetence.

  View details for DOI 10.1016/j.cell.2013.10.034

  View details for PubMedID 24267896

• Aspergillus fumigatus Invasion Increases with Progressive Airway Ischemia PLOS ONE Hsu, J. L., Khan, M. A., Sobel, R. A., Jiang, X., Clemons, K. V., Nguyen, T. T., Stevens, D. A., Martinez, M., Nicolls, M. R. 2013; 8 (10)

  Abstract

  Despite the prevalence of Aspergillus-related disease in immune suppressed lung transplant patients, little is known of the host-pathogen interaction. Because of the mould's angiotropic nature and because of its capacity to thrive in hypoxic conditions, we hypothesized that the degree of Aspergillus invasion would increase with progressive rejection-mediated ischemia of the allograft. To study this relationship, we utilized a novel orthotopic tracheal transplant model of Aspergillus infection, in which it was possible to assess the effects of tissue hypoxia and ischemia on airway infectivity. Laser Doppler flowmetry and FITC-lectin were used to determine blood perfusion, and a fiber optic microsensor was used to measure airway tissue oxygen tension. Fungal burden and depth of invasion were graded using histopathology. We demonstrated a high efficacy (80%) for producing a localized fungal tracheal infection with the majority of infection occurring at the donor-recipient anastomosis; Aspergillus was more invasive in allogeneic compared to syngeneic groups. During the study period, the overall kinetics of both non-infected and infected allografts was similar, demonstrating a progressive loss of perfusion and oxygenation, which reached a nadir by days 10-12 post-transplantation. The extent of Aspergillus invasion directly correlated with the degree of graft hypoxia and ischemia. Compared to the midtrachea, the donor-recipient anastomotic site exhibited lower perfusion and more invasive disease; a finding consistent with clinical experience. For the first time, we identify ischemia as a putative risk factor for Aspergillus invasion. Therapeutic approaches focused on preserving vascular health may play an important role in limiting Aspergillus infections.

  View details for DOI 10.1371/journal.pone.0077136

  View details for Web of Science ID 000325887300058

  View details for PubMedID 24155924

  View details for PubMedCentralID PMC3796538

• Tie2-dependent VHL knockdown promotes airway microvascular regeneration and attenuates invasive growth of Aspergillus fumigatus JOURNAL OF MOLECULAR MEDICINE-JMM Jiang, X., Hsu, J. L., Tian, W., Yuan, K., Olcholski, M., Perez, V. D., Semenza, G. L., Nicolls, M. R. 2013; 91 (9): 1081-1093

  Abstract

  Microvascular ischemia and infections are associated with the development of chronic rejection following lung transplantation. The von Hippel-Lindau protein (VHL) controls protein levels of hypoxia-inducible factors (HIFs), regulates vascular repair, and improves tissue perfusion. Here, we studied the role of VHL in microvascular repair by orthotopically transplanting tracheas into mice with VHL haplodeficiency in Tie2 lineage cells. We showed that VHL haplodeficiency prolonged airway microvascular perfusion and promoted tissue blood flow through the production of the angiogenic factors, SDF-1 and angiopoietin 1. VHL-haplodeficient pulmonary endothelial cells exhibited increased angiogenic activity, resistance to serum deprivation-induced cell death, and enhanced microvascular repair. By contrast, in recipient mice with HIF-1α deficiency in Tie2 lineage cells, microvascular repair was significantly diminished and suggested that recipient-derived HIF-1α normally participates in the repair of alloimmune-mediated microvascular damage. To evaluate the translational impact of our findings, we compared VHL-haplodeficient mice with wild-type controls using a model of Aspergillus airway infection. In 83 % of the VHL-haplodeficient recipients, Aspergillus fumigatus was noninvasive in contrast to 75 % of wild-type mice in which the mold was deeply invasive. Our study demonstrated that stabilization of HIF-1α in angiogenic cells, through Tie2 cell VHL haplodeficiency, promoted airway microvascular regeneration and vascular normalization and thereby minimized tissue ischemia and hypoxia. By also mitigating the virulence of A. fumigatus, a common pathogen and itself a risk factor for the development of lung transplant rejection, the selective enhancement of HIF-1α expression has the prospect of offering several novel therapeutic effects to transplant recipients.Microvascular loss and prolonged ischemia occurs with acute rejection. Von Hippel-Lindau (VHL) protein controls hypoxia inducible factors (HIFs). In tracheal allografts, VHL haplodeficient Tie2 cells promote neovascularization. Reduced transplant ischemia limits Aspergillus invasion.

  View details for DOI 10.1007/s00109-013-1063-8

  View details for Web of Science ID 000324068100007

• Blocking Macrophage Leukotriene B-4 Prevents Endothelial Injury and Reverses Pulmonary Hypertension SCIENCE TRANSLATIONAL MEDICINE Tian, W., Jiang, X., Tamosiuniene, R., Sung, Y. K., Qian, J., Dhillon, G., Gera, L., Farkas, L., Rabinovitch, M., Zamanian, R. T., Inayathullah, M., Fridlib, M., Rajadas, J., Peters-Golden, M., Voelkel, N. F., Nicolls, M. R. 2013; 5 (200)

  Abstract

  Pulmonary hypertension (PH) is a serious condition that affects mainly young and middle-aged women, and its etiology is poorly understood. A prominent pathological feature of PH is accumulation of macrophages near the arterioles of the lung. In both clinical tissue and the SU5416 (SU)/athymic rat model of severe PH, we found that the accumulated macrophages expressed high levels of leukotriene A4 hydrolase (LTA4H), the biosynthetic enzyme for leukotriene B4 (LTB4). Moreover, macrophage-derived LTB4 directly induced apoptosis in pulmonary artery endothelial cells (PAECs). Further, LTB4 induced proliferation and hypertrophy of human pulmonary artery smooth muscle cells. We found that LTB4 acted through its receptor, BLT1, to induce PAEC apoptosis by inhibiting the protective endothelial sphingosine kinase 1 (Sphk1)-endothelial nitric oxide synthase (eNOS) pathway. Blocking LTA4H decreased in vivo LTB4 levels, prevented PAEC apoptosis, restored Sphk1-eNOS signaling, and reversed fulminant PH in the SU/athymic rat model of PH. Antagonizing BLT1 similarly reversed established PH. Inhibition of LTB4 biosynthesis or signal transduction in SU-treated athymic rats with established disease also improved cardiac function and reopened obstructed arterioles; this approach was also effective in the monocrotaline model of severe PH. Human plexiform lesions, one hallmark of PH, showed increased numbers of macrophages, which expressed LTA4H, and patients with connective tissue disease-associated pulmonary arterial hypertension exhibited significantly higher LTB4 concentrations in the systemic circulation than did healthy subjects. These results uncover a possible role for macrophage-derived LTB4 in PH pathogenesis and identify a pathway that may be amenable to therapeutic targeting.

  View details for Web of Science ID 000323705100010

• Tie2-dependent VHL knockdown promotes airway microvascular regeneration and attenuates invasive growth of Aspergillus fumigatus. Journal of molecular medicine (Berlin, Germany) Jiang, X., Hsu, J. L., Tian, W., Yuan, K., Olcholski, M., de Jesus Perez, V., Semenza, G. L., Nicolls, M. R. 2013

  Abstract

  Microvascular ischemia and infections are associated with the development of chronic rejection following lung transplantation. The von Hippel-Lindau protein (VHL) controls protein levels of hypoxia-inducible factors (HIFs), regulates vascular repair, and improves tissue perfusion. Here, we studied the role of VHL in microvascular repair by orthotopically transplanting tracheas into mice with VHL haplodeficiency in Tie2 lineage cells. We showed that VHL haplodeficiency prolonged airway microvascular perfusion and promoted tissue blood flow through the production of the angiogenic factors, SDF-1 and angiopoietin 1. VHL-haplodeficient pulmonary endothelial cells exhibited increased angiogenic activity, resistance to serum deprivation-induced cell death, and enhanced microvascular repair. By contrast, in recipient mice with HIF-1α deficiency in Tie2 lineage cells, microvascular repair was significantly diminished and suggested that recipient-derived HIF-1α normally participates in the repair of alloimmune-mediated microvascular damage. To evaluate the translational impact of our findings, we compared VHL-haplodeficient mice with wild-type controls using a model of Aspergillus airway infection. In 83 % of the VHL-haplodeficient recipients, Aspergillus fumigatus was noninvasive in contrast to 75 % of wild-type mice in which the mold was deeply invasive. Our study demonstrated that stabilization of HIF-1α in angiogenic cells, through Tie2 cell VHL haplodeficiency, promoted airway microvascular regeneration and vascular normalization and thereby minimized tissue ischemia and hypoxia. By also mitigating the virulence of A. fumigatus, a common pathogen and itself a risk factor for the development of lung transplant rejection, the selective enhancement of HIF-1α expression has the prospect of offering several novel therapeutic effects to transplant recipients.Microvascular loss and prolonged ischemia occurs with acute rejection. Von Hippel-Lindau (VHL) protein controls hypoxia inducible factors (HIFs). In tracheal allografts, VHL haplodeficient Tie2 cells promote neovascularization. Reduced transplant ischemia limits Aspergillus invasion.

  View details for DOI 10.1007/s00109-013-1063-8

  View details for PubMedID 23797537

• Epithelial to mesenchymal transition in murine tracheal allotransplantation: an immunohistochemical observation. Transplantation proceedings Konoeda, C., Koinuma, D., Morishita, Y., Sano, A., Nagayama, K., Motomura, N., Kakimi, K., MIYAZONO, K., Nakajima, J., Nicolls, M. R., Murakawa, T. 2013; 45 (5): 1797-1801

  Abstract

  Aberrant epithelial repair is a crucial event in the airway remodeling that characterizes obliterative bronchiolitis (OB) in transplanted lungs. Recent data from experiments using epithelial cell lines and human airway tissues from lung transplant recipients suggest that epithelial to mesenchymal transition (EMT) plays an important role in OB. The aim of this study was to clarify whether EMT is involved in airway remodeling in an animal model.We performed orthotopic tracheal transplantation from BALB/c to C57BL/6 mice with from BALC/c to BALB/c mouse grafts as controls. Five allogeneic and 3 syngeneic recipients were humanely killed at predetermined postoperative days 2-12 as well as 14 and 21. Histology was evaluated using hematoxylin-eosin (H&E) staining. We studied the expression of specific markers, including E-cadherin, an epithelial marker; α-smooth muscle actin (SMA), and S100A4, mesenchymal markers, and zinc finger E-box-binding homeobox 1 (ZEB1), an EMT-related transcription factor.Histologic assessment of serial H&E stains of allogeneic grafts showed remarkable pseudostratified respiratory epithelium with subepithelial inflammatory cell infiltration, as well as denuded and flattened epithelium and subepithelial fibrosis. The dynamic epithelial changes occurred earlier than the subepithelial fibrosis. Immunohistochemical evaluation indicated the emergence of α-SMA- positive epithelial cells that were most prominent on day 7. The expression of E-cadherin was attenuated in α-SMA-positive epithelial cells. S100A4 was also expressed in epithelial cells. A few days before the intraepithelial expression of α-SMA, ZEB1 emerged in the nuclei of epithelial cells.We observed expression of an EMT-related transcription factor and mesenchymal markers along with the attenuation of epithelial marker expression in epithelial cells, several days before prominent subepithelial fibrosis formation, results that suggest epithelial cells to play an important fibrosis role in airway remodeling during epithelial to mesenchymal transition.

  View details for DOI 10.1016/j.transproceed.2012.11.024

  View details for PubMedID 23769046

• Targeting complement component 5a promotes vascular integrity and limits airway remodeling. Proceedings of the National Academy of Sciences of the United States of America Khan, M. A., Maasch, C., Vater, A., Klussmann, S., Morser, J., Leung, L. L., Atkinson, C., Tomlinson, S., Heeger, P. S., Nicolls, M. R. 2013; 110 (15): 6061-6066

  Abstract

  Increased microvascular dilatation and permeability is observed during allograft rejection. Because vascular integrity is an important indicator of transplant health, we have sought to limit injury to blood vessels by blocking complement activation. Although complement component 3 (C3) inhibition is known to be vasculoprotective in transplantation studies, we recently demonstrated the paradoxical finding that, early in rejection, C3(-/-) transplant recipients actually exhibit worse microvascular injury than controls. In the genetic absence of C3, thrombin-mediated complement component 5 (C5) convertase activity leads to the generation of C5a (anaphylatoxin), a promoter of vasodilatation and permeability. In the current study, we demonstrated that microvessel thrombin deposition is significantly increased in C3(-/-) recipients during acute rejection. Thrombin colocalization with microvessels is closely associated with remarkably elevated plasma levels of C5a, vasodilatation, and increased vascular permeability. Administration of NOX-D19, a specific C5a inhibitor, to C3(-/-) recipients of airway transplants significantly improved tissue oxygenation, limited microvascular leakiness, and prevented airway ischemia, even in the absence of conventional T-cell-directed immunosuppression. As C3 inhibitors enter the clinics, the simultaneous targeting of this thrombin-mediated complement activation pathway and/or C5a itself may confer significant clinical benefit.

  View details for DOI 10.1073/pnas.1217991110

  View details for PubMedID 23530212

  View details for PubMedCentralID PMC3625314

• Editorial: Developing Better Biomarkers for Connective Tissue DiseaseAssociated Interstitial Lung Disease: Citrullinated Hsp90 Autoantibodies in Rheumatoid Arthritis ARTHRITIS AND RHEUMATISM Deane, K. D., Nicolls, M. R. 2013; 65 (4): 864-868

  View details for DOI 10.1002/art.37878

  View details for Web of Science ID 000316962000004

  View details for PubMedID 23400799

• Complement-mediated microvascular injury leads to chronic rejection. Advances in experimental medicine and biology Khan, M. A., Nicolls, M. R. 2013; 735: 233-246

  Abstract

  Microvascular loss may be an unappreciated root cause of chronic rejection for all solid organ transplants. As the only solid organ transplant that does not undergo primary systemic arterial revascularization at the time of surgery, lung transplants rely on the establishment of a microcirculation and are especially vulnerable to the effects of microvascular loss. Microangiopathy, with its attendant ischemia, can lead to tissue infarction and airway fibrosis. Maintaining healthy vasculature in lung allografts may be critical for preventing terminal airway fibrosis, also known as the bronchiolitis obliterans syndrome (BOS). BOS is the major obstacle to lung transplant success and affects up to 60% of patients surviving 5 years. The role of complement in causing acute microvascular loss and ischemia during rejection has recently been examined using the mouse orthotopic tracheal transplantation; this is an ideal model for parsing the role of airway vasculature in rejection. Prior to the development of airway fibrosis in rejecting tracheal allografts, C3 deposits on the vascular endothelium just as tissue hypoxia is first detected. With the eventual destruction of vessels, microvascular blood flow to the graft stops altogether for several days. Complement deficiency and complement inhibition lead to markedly improved tissue oxygenation in transplants, diminished airway remodeling, and accelerated vascular repair. CD4+ T cells and antibody-dependent complement activity independently mediate vascular destruction and sustained tissue ischemia during acute rejection. Consequently, interceding against complement-mediated microvascular injury with adjunctive therapy during acute rejection episodes, in addition to standard immunosuppression which targets CD4+ T cells, may help prevent the subsequent development of chronic rejection.

  View details for PubMedID 23402031

• Unique Predictors Of Mortality In Patients With Pulmonary Arterial Hypertension Associated With Systemic Sclerosis In The Reveal Registry (R) Chung, L., Farber, H. W., Benza, R. L., Miller, D. P., Parsons, L. S., Hassoun, P. M., McGoon, M. D., Nicolls, M. R., Zamanian, R. T. AMER THORACIC SOC. 2013

  View details for Web of Science ID 000209838402168

• Lox Inhibitor Synergizes With Cellular Softening By Relaxin To Attenuate Airway Fibrosis In Mouse Orthotopic Tracheal Transplantation Model Lin, Y., Jiang, X., Khan, M. A., Nicolls, M. R. AMER THORACIC SOC. 2013

  View details for Web of Science ID 000209838403032

• Pathobiology of pulmonary arterial hypertension and right ventricular failure EUROPEAN RESPIRATORY JOURNAL Voelkel, N. F., Gomez-Arroyo, J., Abbate, A., Bogaard, H. J., Nicolls, M. R. 2012; 40 (6): 1555-1565

  Abstract

  Pulmonary arterial hypertension (PAH) is no longer an orphan disease. There are three different classes of drugs for the treatment of PAH that are currently being used and an increasing number of patients are being treated with a single drug or combination therapy. During the last 25 yrs, new insights into the pathobiology of PAH have been gained. The classical mechanical concepts of pressure, flow, shear stress, right ventricle wall stress and impedance have been complemented with the new concepts of cell injury and repair and interactions of complex multicellular systems. Integrating these concepts will become critical as we design new medical therapies in order to change the prognosis of patients with these fatal diseases. This review intends to summarise recent pathobiological concepts of PAH and right ventricle failure mainly derived from human studies, which reflect the progress made in the understanding of this complex group of pulmonary vascular diseases.

  View details for DOI 10.1183/09031936.00046612

  View details for Web of Science ID 000312055200033

  View details for PubMedID 22743666

• Activation of Classical Complement Pathway is Associated with the Development of Idiopathic Pulmonary Arterial Hypertension (IPAH) Saito, T., Sharpe, O., Harada, D., Tamosiuniene, R., Li, C. G., Nicolls, M., Robinson, W. H., Rabinovitch, M. LIPPINCOTT WILLIAMS & WILKINS. 2012

  View details for Web of Science ID 000208885006195

• Severe Pulmonary Arterial Hypertension Induced by SU5416 and Ovalbumin Immunization AMERICAN JOURNAL OF RESPIRATORY CELL AND MOLECULAR BIOLOGY Mizuno, S., Farkas, L., Al Husseini, A., Farkas, D., Gomez-Arroyo, J., Kraskauskas, D., Nicolls, M. R., Cool, C. D., Bogaard, H. J., Voelkel, N. F. 2012; 47 (5): 679-687

  Abstract

  The combination of chronic hypoxia and treatment of rats with the vascular endothelial growth factor (VEGF) receptor blocker, SU5416, induces pulmonary angio-obliteration, resulting in severe pulmonary arterial hypertension (PAH). Inflammation is thought to contribute to the pathology of PAH. Allergic inflammation caused by ovalbumin (OVA) immunization causes muscularization of pulmonary arteries, but not severe PAH. Whether disturbance of the immune system and allergic inflammation in the setting of lung endothelial cell apoptosis causes PAH is unknown. We investigated the effects of OVA-allergic inflammation on the development of PAH initiated by VEGF blockade-induced lung endothelial cell apoptosis. OVA-immunized rats were treated with SU5416 to induce pulmonary vascular endothelial cell apoptosis. The combination of OVA and SU5416 treatment resulted in severe angio-obilterative PAH, accompanied by increased IL-6 expression in the lungs. c-Kit(+) and Sca-1(+) cells were found in and around the lung vascular lesions. Pan-caspase inhibiton, dexamethasone treatment, and depletion of B-lymphocytes using an anti-CD20 antibody suppressed this remodeling. OVA immunization also increased lung tissue hypoxia-induced factor-1α and VEGF expression. Our results also suggest that the increased expression of hypoxia-induced factor-1α and IL-6 induced by the allergic lung inflammation may be a component of the pathogenesis of PAH.

  View details for DOI 10.1165/rcmb.2012-0077OC

  View details for Web of Science ID 000314406400015

  View details for PubMedID 22842496

• New methods for monitoring dynamic airway tissue oxygenation and perfusion in experimental and clinical transplantation AMERICAN JOURNAL OF PHYSIOLOGY-LUNG CELLULAR AND MOLECULAR PHYSIOLOGY Khan, M. A., Dhillon, G., Jiang, X., Lin, Y., Nicolls, M. R. 2012; 303 (10): L861-L869

  Abstract

  A dual circulation, supplied by bronchial and pulmonary artery-derived vessels, normally perfuses the airways from the trachea to the terminal bronchioles. This vascular system has been highly conserved through mammalian evolution and is disrupted at the time of lung transplantation. In most transplant centers, this circulation is not restored. The Papworth Hospital Autopsy study has revealed that an additional attrition of periairway vessels is associated with the development of chronic rejection, otherwise known as the bronchiolitis obliterans syndrome (BOS). Experimental studies subsequently demonstrated that airway vessels are subject to alloimmune injury and that the loss of a functional microvascular system identifies allografts that cannot be rescued with immunosuppressive therapy. Therefore, surgical and medical strategies, which preserve the functionality of the existent vasculature in lung transplant patients, may conceivably limit the incidence of BOS. Given these unique anatomic and physiological considerations, there is an emerging rationale to better understand the perfusion and oxygenation status of airways in transplanted lungs. This article describes novel methodologies, some newly developed by our group, for assessing airway tissue oxygenation and perfusion in experimental and clinical transplantation.

  View details for DOI 10.1152/ajplung.00162.2012

  View details for PubMedID 23002078

• New models of pulmonary hypertension based on VEGF receptor blockade-induced endothelial cell apoptosis. Pulmonary circulation Nicolls, M. R., Mizuno, S., Taraseviciene-Stewart, L., Farkas, L., Drake, J. I., Al Husseini, A., Gomez-Arroyo, J. G., Voelkel, N. F., Bogaard, H. J. 2012; 2 (4): 434-442

  Abstract

  In spite of treatment, severe angioproliferative pulmonary arterial hypertension (PAH) remains a disease characterized by great morbidity and shortened survival. New treatment strategies for patients with PAH are needed, and after drug development, preclinical studies are best conducted in animal models which present with pulmonary angio-obliterative disease and right heart failure. A rat model of severe pulmonary hypertension and right heart failure, described a decade ago, continues to be investigated and provide insight into the nature of the lung vascular lesions and mechanisms of cardiac adaptation to an altered lung circulation. This rat model is based on the combination of VEGF receptor blockade with Su5416 and chronic hypoxia; use of this pulmonary hypertension induction strategy led to developing the concept of apoptosis-dependent compensatory vascular cell growth. Although, often employed in experimental designs, chronic hypoxia is not necessary for the development of angio-obliterative pulmonary hypertension. Left pneumonectomy combined with Su5416 also results in severe pulmonary hypertension in normoxic conditions. Similarly, the immune insufficiency component of severe PAH can be modeled in athymic rats (lacking T-lymphocytes). In these rats housed under normoxic conditions, treatment with the VEGFR receptor blocker results in angioproliferative pulmonary hypertension; cardiopulmonary disease in these animals can be prevented by immune reconstitution of regulatory T-cells (Tregs). Finally, chronic hypoxia can be replaced with another stimulator of HIF-1α: Ovalbumin (Ova). Immunization of rats with Ova increases lung tissue HIF-1α protein expression, and in Su5416-treated rats causes lethal pulmonary hypertension. Finally, we postulate that these models may also be useful for "reverse translation"; that is, the mechanisms of lung vascular cell death and growth and the modifying influences of immune and bone marrow cells that have been identified in the Su5416 VEGFR inhibitor models can be informative about heretofore undescribed processes in human PAH.

  View details for DOI 10.4103/2045-8932.105031

  View details for PubMedID 23372927

  View details for PubMedCentralID PMC3555413

• Potential for overuse of corticosteroids and vasopressin in septic shock. Critical care (London, England) Hsu, J. L., Liu, V., Patterson, A. J., Martin, G. S., Nicolls, M. R., Russell, J. A. 2012; 16 (5): 447

  View details for DOI 10.1186/cc11460

  View details for PubMedID 23102413

• Change in diffusing capacity for carbon monoxide as a predictor of outcomes in connective tissue disease-associated pulmonary arterial hypertension: Analysis from the REVEAL registry Zamanian, R., Kudelko, K., Miller, D., McGoon, M., Benza, R., Hassoun, P., Nicolls, M., Chung, L. EUROPEAN RESPIRATORY SOC JOURNALS LTD. 2012

  View details for Web of Science ID 000449650903554

• Neonatal mice genetically modified to express the elastase inhibitor elafin are protected against the adverse effects of mechanical ventilation on lung growth. American journal of physiology. Lung cellular and molecular physiology Hilgendorff, A., Parai, K., Ertsey, R., Juliana Rey-Parra, G., Thébaud, B., Tamosiuniene, R., Jain, N., Navarro, E. F., Starcher, B. C., Nicolls, M. R., Rabinovitch, M., Bland, R. D. 2012; 303 (3): L215-27

  Abstract

  Mechanical ventilation (MV) with O(2)-rich gas (MV-O(2)) offers life-saving treatment for newborn infants with respiratory failure, but it also can promote lung injury, which in neonates translates to defective alveolar formation and disordered lung elastin, a key determinant of lung growth and repair. Prior studies in preterm sheep and neonatal mice showed that MV-O(2) stimulated lung elastase activity, causing degradation and remodeling of matrix elastin. These changes yielded an inflammatory response, with TGF-β activation, scattered elastic fibers, and increased apoptosis, culminating in defective alveolar septation and arrested lung growth. To see whether sustained inhibition of elastase activity would prevent these adverse pulmonary effects of MV-O(2), we did studies comparing wild-type (WT) and mutant neonatal mice genetically modified to express in their vascular endothelium the human serine elastase inhibitor elafin (Eexp). Five-day-old WT and Eexp mice received MV with 40% O(2) (MV-O(2)) for 24-36 h. WT and Eexp controls breathed 40% O(2) without MV. MV-O(2) increased lung elastase and MMP-9 activity, resulting in elastin degradation (urine desmosine doubled), TGF-β activation (pSmad-2 increased 6-fold), apoptosis (cleaved-caspase-3 increased 10-fold), and inflammation (NF-κB activation, influx of neutrophils and monocytes) in lungs of WT vs. unventilated controls. These changes were blocked or blunted during MV-O(2) of Eexp mice. Scattered lung elastin and emphysematous alveoli observed in WT mice after 36 h of MV-O(2) were attenuated in Eexp mice. Both WT and Eexp mice showed defective VEGF signaling (decreased lung VEGF-R2 protein) and loss of pulmonary microvessels after lengthy MV-O(2), suggesting that elafin's beneficial effects during MV-O(2) derived primarily from preserving matrix elastin and suppressing lung inflammation, thereby enabling alveolar formation during MV-O(2). These results suggest that degradation and remodeling of lung elastin can contribute to defective lung growth in response to MV-O(2) and might be targeted therapeutically to prevent ventilator-induced neonatal lung injury.

  View details for DOI 10.1152/ajplung.00405.2011

  View details for PubMedID 22683569

  View details for PubMedCentralID PMC3423862

• Neonatal mice genetically modified to express the elastase inhibitor elafin are protected against the adverse effects of mechanical ventilation on lung growth AMERICAN JOURNAL OF PHYSIOLOGY-LUNG CELLULAR AND MOLECULAR PHYSIOLOGY Hilgendorff, A., Parai, K., Ertsey, R., Rey-Parra, G. J., Thebaud, B., Tamosiuniene, R., Jain, N., Navarro, E. F., Starcher, B. C., Nicolls, M. R., Rabinovitch, M., Bland, R. D. 2012; 303 (3): L215-L227

  Abstract

  Mechanical ventilation (MV) with O(2)-rich gas (MV-O(2)) offers life-saving treatment for newborn infants with respiratory failure, but it also can promote lung injury, which in neonates translates to defective alveolar formation and disordered lung elastin, a key determinant of lung growth and repair. Prior studies in preterm sheep and neonatal mice showed that MV-O(2) stimulated lung elastase activity, causing degradation and remodeling of matrix elastin. These changes yielded an inflammatory response, with TGF-β activation, scattered elastic fibers, and increased apoptosis, culminating in defective alveolar septation and arrested lung growth. To see whether sustained inhibition of elastase activity would prevent these adverse pulmonary effects of MV-O(2), we did studies comparing wild-type (WT) and mutant neonatal mice genetically modified to express in their vascular endothelium the human serine elastase inhibitor elafin (Eexp). Five-day-old WT and Eexp mice received MV with 40% O(2) (MV-O(2)) for 24-36 h. WT and Eexp controls breathed 40% O(2) without MV. MV-O(2) increased lung elastase and MMP-9 activity, resulting in elastin degradation (urine desmosine doubled), TGF-β activation (pSmad-2 increased 6-fold), apoptosis (cleaved-caspase-3 increased 10-fold), and inflammation (NF-κB activation, influx of neutrophils and monocytes) in lungs of WT vs. unventilated controls. These changes were blocked or blunted during MV-O(2) of Eexp mice. Scattered lung elastin and emphysematous alveoli observed in WT mice after 36 h of MV-O(2) were attenuated in Eexp mice. Both WT and Eexp mice showed defective VEGF signaling (decreased lung VEGF-R2 protein) and loss of pulmonary microvessels after lengthy MV-O(2), suggesting that elafin's beneficial effects during MV-O(2) derived primarily from preserving matrix elastin and suppressing lung inflammation, thereby enabling alveolar formation during MV-O(2). These results suggest that degradation and remodeling of lung elastin can contribute to defective lung growth in response to MV-O(2) and might be targeted therapeutically to prevent ventilator-induced neonatal lung injury.

  View details for DOI 10.1152/ajplung.00405.2011

  View details for Web of Science ID 000307220000006

  View details for PubMedCentralID PMC3423862

• A brief overview of mouse models of pulmonary arterial hypertension: problems and prospects AMERICAN JOURNAL OF PHYSIOLOGY-LUNG CELLULAR AND MOLECULAR PHYSIOLOGY Gomez-Arroyo, J., Saleem, S. J., Mizuno, S., Syed, A. A., Bogaard, H. J., Abbate, A., Taraseviciene-Stewart, L., Sung, Y., Kraskauskas, D., Farkas, D., Conrad, D. H., Nicolls, M. R., Voelkel, N. F. 2012; 302 (10): L977-L991

  Abstract

  Many chronic pulmonary diseases are associated with pulmonary hypertension (PH) and pulmonary vascular remodeling, which is a term that continues to be used to describe a wide spectrum of vascular abnormalities. Pulmonary vascular structural changes frequently increase pulmonary vascular resistance, causing PH and right heart failure. Although rat models had been standard models of PH research, in more recent years the availability of genetically engineered mice has made this species attractive for many investigators. Here we review a large amount of data derived from experimental PH reports published since 1996. These studies using wild-type and genetically designed mice illustrate the challenges and opportunities provided by these models. Hemodynamic measurements are difficult to obtain in mice, and right heart failure has not been investigated in mice. Anatomical, cellular, and genetic differences distinguish mice and rats, and pharmacogenomics may explain the degree of PH and the particular mode of pulmonary vascular adaptation and also the response of the right ventricle.

  View details for DOI 10.1152/ajplung.00362.2011

  View details for Web of Science ID 000304357600001

  View details for PubMedID 22307907

  View details for PubMedCentralID PMC3774477

• Potential for overuse of corticosteroids and vasopressin in septic shock CRITICAL CARE Hsu, J. L., Liu, V., Patterson, A. J., Martin, G. S., Nicolls, M. R., Russell, J. A. 2012; 16 (5)

  View details for DOI 10.1186/cc11460

  View details for Web of Science ID 000317499900077

• CD4(+) T Cells and Complement Independently Mediate Graft Ischemia in the Rejection of Mouse Orthotopic Tracheal Transplants CIRCULATION RESEARCH Khan, M. A., Jiang, X., Dhillon, G., Beilke, J., Holers, V. M., Atkinson, C., Tomlinson, S., Nicolls, M. R. 2011; 109 (11): 1290-U256

  Abstract

  While microvascular injury is associated with chronic rejection, the cause of tissue ischemia during alloimmune injury is not yet elucidated.We investigated the contribution of T lymphocytes and complement to microvascular injury-associated ischemia during acute rejection of mouse tracheal transplants.Using novel techniques to assess microvascular integrity and function, we evaluated how lymphocyte subsets and complement specifically affect microvascular perfusion and tissue oxygenation in MHC-mismatched transplants. To characterize T cell effects on microvessel loss and recovery, we transplanted functional airway grafts in the presence and absence of CD4(+) and CD8(+) T cells. To establish the contribution of complement-mediated injury to the allograft microcirculation, we transplanted C3-deficient and C3-inhibited recipients. We demonstrated that CD4(+) T cells and complement are independently sufficient to cause graft ischemia. CD8(+) T cells were required for airway neovascularization to occur following CD4-mediated rejection. Activation of antibody-dependent complement pathways mediated tissue ischemia even in the absence of cellular rejection. Complement inhibition by CR2-Crry attenuated graft hypoxia, complement/antibody deposition on vascular endothelium and promoted vascular perfusion by enhanced angiogenesis. Finally, there was a clear relationship between the burden of tissue hypoxia (ischemia×time duration) and the development of subsequent airway remodeling.These studies demonstrated that CD4(+) T cells and complement operate independently to cause transplant ischemia during acute rejection and that sustained ischemia is a precursor to chronic rejection.

  View details for DOI 10.1161/CIRCRESAHA.111.250167

  View details for PubMedID 21998328

• Functional Class Change in Patients with Connective Tissue Disease-Associated Pulmonary Arterial Hypertension: Associations with Survival and Exercise Capacity Chung, L., Parsons, L. S., Hassoun, P. M., McGoon, M. D., Badesch, D. B., Miller, D. P., Nicolls, M. R., Zamanian, R. T. WILEY-BLACKWELL. 2011: S575

  View details for Web of Science ID 000297621501665

• Regulatory T Cells Limit Vascular Endothelial Injury and Prevent Pulmonary Hypertension CIRCULATION RESEARCH Tamosiuniene, R., Tian, W., Dhillon, G., Wang, L., Sung, Y. K., Gera, L., Patterson, A. J., Agrawal, R., Rabinovitch, M., Ambler, K., Long, C. S., Voelkel, N. F., Nicolls, M. R. 2011; 109 (8): 867-U120

  Abstract

  Pulmonary arterial hypertension (PAH) is an incurable disease associated with viral infections and connective tissue diseases. The relationship between inflammation and disease pathogenesis in these disorders remains poorly understood.To determine whether immune dysregulation due to absent T-cell populations directly contributes to the development of PAH.Vascular endothelial growth factor receptor 2 (VEGFR2) blockade induced significant pulmonary endothelial apoptosis in T-cell-deficient rats but not in immune-reconstituted (IR) rats. T cell-lymphopenia in association with VEGFR2 blockade resulted in periarteriolar inflammation with macrophages, and B cells even prior to vascular remodeling and elevated pulmonary pressures. IR prevented early inflammation and attenuated PAH development. IR with either CD8 T cells alone or with CD4-depleted spleen cells was ineffective in preventing PAH, whereas CD4-depleting immunocompetent euthymic animals increased PAH susceptibility. IR with either CD4(+)CD25(hi) or CD4(+)CD25(-) T cell subsets prior to vascular injury attenuated the development of PAH. IR limited perivascular inflammation and endothelial apoptosis in rat lungs in association with increased FoxP3(+), IL-10- and TGF-β-expressing CD4 cells, and upregulation of pulmonary bone morphogenetic protein receptor type 2 (BMPR2)-expressing cells, a receptor that activates endothelial cell survival pathways.PAH may arise when regulatory T-cell (Treg) activity fails to control endothelial injury. These studies suggest that regulatory T cells normally function to limit vascular injury and may protect against the development of PAH.

  View details for DOI 10.1161/CIRCRESAHA.110.236927

  View details for PubMedID 21868697

• Inhibiting Lung Elastase Activity Enables Lung Growth in Mechanically Ventilated Newborn Mice AMERICAN JOURNAL OF RESPIRATORY AND CRITICAL CARE MEDICINE Hilgendorff, A., Parai, K., Ertsey, R., Jain, N., Navarro, E. F., Peterson, J. L., Tamosiuniene, R., Nicolls, M. R., Starcher, B. C., Rabinovitch, M., Bland, R. D. 2011; 184 (5): 537-546

  Abstract

  Mechanical ventilation with O₂-rich gas (MV-O₂) offers life-saving treatment for respiratory failure, but also promotes lung injury. We previously reported that MV-O2 of newborn mice increased lung elastase activity, causing elastin degradation and redistribution of elastic fibers from septal tips to alveolar walls. These changes were associated with transforming growth factor (TGF)-β activation and increased apoptosis leading to defective alveolarization and lung growth arrest, as seen in neonatal chronic lung disease.To determine if intratracheal treatment of newborn mice with the serine elastase inhibitor elafin would prevent MV-O₂-induced lung elastin degradation and the ensuing cascade of events causing lung growth arrest.Five-day-old mice were treated via tracheotomy with recombinant human elafin or vehicle (lactated-Ringer solution), followed by MV with 40% O₂ for 8-24 hours; control animals breathed 40% O₂ without MV. At study's end, lungs were harvested to assess key variables noted below.MV-O₂ of vehicle-treated pups increased lung elastase and matrix metalloproteinase-9 activity when compared with unventilated control animals, causing elastin degradation (urine desmosine doubled), TGF-β activation (pSmad-2 tripled), and apoptosis (cleaved-caspase-3 increased 10-fold). Quantitative lung histology showed larger and fewer alveoli, greater inflammation, and scattered elastic fibers. Elafin blocked these MV-O₂-induced changes.Intratracheal elafin, by blocking lung protease activity, prevented MV-O₂-induced elastin degradation, TGF-β activation, apoptosis, and dispersion of matrix elastin, and attenuated lung structural abnormalities noted in vehicle-treated mice after 24 hours of MV-O₂. These findings suggest that elastin breakdown contributes to defective lung growth in response to MV-O₂ and might be targeted therapeutically to prevent MV-O₂-induced lung injury.

  View details for DOI 10.1164/rccm.201012-2010OC

  View details for Web of Science ID 000294478200014

  View details for PubMedID 21562133

  View details for PubMedCentralID PMC3175547

• Regulatory T Cells and Pulmonary Hypertension TRENDS IN CARDIOVASCULAR MEDICINE Tamosiuniene, R., Nicolls, M. R. 2011; 21 (6): 166-171

  Abstract

  Pulmonary hypertension (PH) is a disease of high lethality arising from numerous causes. For a significant subset of PH patients, autoimmune biomarkers or frank autoimmune disease are simultaneously present, but the extent to which lung inflammation contributes to PH is unknown. However, emerging experimental and clinical evidence suggests that immune dysregulation may lead to the propagation of vascular injury and PH. A recent preclinical study demonstrated that regulatory T cells are important mediators normally enlisted to control inflammation and that, if absent or dysfunctional, may predispose to the development of PH.

  View details for Web of Science ID 000306942700003

  View details for PubMedID 22814424

• Adenovirus-mediated HIF-1 alpha gene transfer promotes repair of mouse airway allograft microvasculature and attenuates chronic rejection JOURNAL OF CLINICAL INVESTIGATION Jiang, X., Khan, M. A., Tian, W., Beilke, J., Natarajan, R., Kosek, J., Yoder, M. C., Semenza, G. L., Nicolls, M. R. 2011; 121 (6): 2336-2349

  Abstract

  Chronic rejection, manifested as small airway fibrosis (obliterative bronchiolitis [OB]), is the main obstacle to long-term survival in lung transplantation. Recent studies demonstrate that the airways involved in a lung transplant are relatively hypoxic at baseline and that OB pathogenesis may be linked to ischemia induced by a transient loss of airway microvasculature. Here, we show that HIF-1α mediates airway microvascular repair in a model of orthotopic tracheal transplantation. Grafts with a conditional knockout of Hif1a demonstrated diminished recruitment of recipient-derived Tie2⁺ angiogenic cells to the allograft, impaired repair of damaged microvasculature, accelerated loss of microvascular perfusion, and hastened denudation of epithelial cells. In contrast, graft HIF-1α overexpression induced via an adenoviral vector prolonged airway microvascular perfusion, preserved epithelial integrity, extended the time window for the graft to be rescued from chronic rejection, and attenuated airway fibrotic remodeling. HIF-1α overexpression induced the expression of proangiogenic factors such as Sdf1, Plgf, and Vegf, and promoted the recruitment of vasoreparative Tie2⁺ cells. This study demonstrates that a therapy that enhances vascular integrity during acute rejection may promote graft health and prevent chronic rejection.

  View details for DOI 10.1172/JCI46192

  View details for Web of Science ID 000291234300032

  View details for PubMedID 21606594

  View details for PubMedCentralID PMC3104770

• Survival in Pulmonary Hypertension Registries The Importance of Incident Cases Response CHEST Chung, L., Liu, J., Parsons, L. S., Hassoun, P. M., McGoon, M. D., Badesch, D. B., Miller, D. P., Nicolls, M. R., Zamanian, R. T. 2011; 139 (6): 1548-1549

  View details for DOI 10.1378/chest.11-0341

  View details for Web of Science ID 000291511100050

• The Role of C3 Activation in Airway Hypoxia and Ischemia in Murine Model of Orthotopic Tracheal Transplantation 31st Annual Meeting and Scientific Sessions of the International-Society-for-Heart-and-Lung-Transplantation (ISHLT) Khan, M. A., Jiang, X., Atkinson, C., Tomlinson, S., Nicolls, M. R. ELSEVIER SCIENCE INC. 2011: S130–S131

  View details for Web of Science ID 000288924300378

• Immunomodulatory strategies prevent the development of autoimmune emphysema RESPIRATORY RESEARCH Hanaoka, M., Nicolls, M. R., Fontenot, A. P., Kraskauskas, D., Mack, D. G., Kratzer, A., Salys, J., Kraskauskiene, V., Burns, N., Voelkel, N. F., Taraseviciene-Stewart, L. 2010; 11

  Abstract

  The presence of anti-endothelial cell antibodies and pathogenic T cells may reflect an autoimmune component in the pathogenesis of emphysema. Whether immune modulatory strategies can protect against the development of emphysema is not known.Sprague Dawley rats were immunized with human umbilical vein endothelial cells (HUVEC) to induce autoimmune emphysema and treated with intrathymic HUVEC-injection and pristane. Measurements of alveolar airspace enlargement, cytokine levels, immuno histochemical, western blot analysis, and T cell repertoire of the lung tissue were performed.The immunomodulatory strategies protected lungs against cell death as demonstrated by reduced numbers of TUNEL and active caspase-3 positive cells and reduced levels of active caspase-3, when compared with lungs from HUVEC-immunized rats. Immunomodulatory strategies also suppressed anti-endothelial antibody production and preserved CNTF, IL-1alpha and VEGF levels. The immune deviation effects of the intrathymic HUVEC-injection were associated with an expansion of CD4+CD25+Foxp3+ regulatory T cells. Pristane treatment decreased the proportion of T cells expressing receptor beta-chain, Vβ16.1 in the lung tissue.Our data demonstrate that interventions classically employed to induce central T cell tolerance (thymic inoculation of antigen) or to activate innate immune responses (pristane treatment) can prevent the development of autoimmune emphysema.

  View details for DOI 10.1186/1465-9921-11-179

  View details for Web of Science ID 000285638200001

  View details for PubMedID 21162738

  View details for PubMedCentralID PMC3009635

• Strategic Plan for Lung Vascular Research An NHLBI-ORDR Workshop Report AMERICAN JOURNAL OF RESPIRATORY AND CRITICAL CARE MEDICINE Erzurum, S., Rounds, S. I., Stevens, T., Aldred, M., Aliotta, J., Archer, S. L., Asosingh, K., Balaban, R., Bauer, N., Bhattacharya, J., Bogaard, H., Choudhary, G., Dorn, G. W., Dweik, R., Fagan, K., Fallon, M., Finkel, T., Geraci, M., Gladwin, M. T., Hassoun, P. M., Humbert, M., Kaminski, N., Kawut, S. M., Loscalzo, J., McDonald, D., McMurtry, I. F., Newman, J., Nicolls, M., Rabinovitch, M., Shizuru, J., Oka, M., Polgar, P., Rodman, D., Schumacker, P., Stenmark, K., Tuder, R., Voelkel, N., Sullivan, E., Weinshilboum, R., Yoder, M. C., Zhao, Y., Gail, D., Moore, T. M. 2010; 182 (12): 1554-1562

  Abstract

  The Division of Lung Diseases of the National Heart, Lung, and Blood Institute, with the Office of Rare Diseases Research, held a workshop to identify priority areas and strategic goals to enhance and accelerate research that will result in improved understanding of the lung vasculature, translational research needs, and ultimately the care of patients with pulmonary vascular diseases. Multidisciplinary experts with diverse experience in laboratory, translational, and clinical studies identified seven priority areas and discussed limitations in our current knowledge, technologies, and approaches. The focus for future research efforts include the following: (1) better characterizing vascular genotype-phenotype relationships and incorporating systems biology approaches when appropriate; (2) advancing our understanding of pulmonary vascular metabolic regulatory signaling in health and disease; (3) expanding our knowledge of the biologic relationships between the lung circulation and circulating elements, systemic vascular function, and right heart function and disease; (4) improving translational research for identifying disease-modifying therapies for the pulmonary hypertensive diseases; (5) establishing an appropriate and effective platform for advancing translational findings into clinical studies testing; and (6) developing the specific technologies and tools that will be enabling for these goals, such as question-guided imaging techniques and lung vascular investigator training programs. Recommendations from this workshop will be used within the Lung Vascular Biology and Disease Extramural Research Program for planning and strategic implementation purposes.

  View details for DOI 10.1164/rccm.201006-0869WS

  View details for Web of Science ID 000285534600016

  View details for PubMedID 20833821

  View details for PubMedCentralID PMC3029941

• Characterization of Connective Tissue Disease-Associated Pulmonary Arterial Hypertension From REVEAL Identifying Systemic Sclerosis as a Unique Phenotype CHEST Chung, L., Liu, J., Parsons, L., Hassoun, P. M., McGoon, M., Badesch, D. B., Miller, D. P., Nicolls, M. R., Zamanian, R. T. 2010; 138 (6): 1383-1394

  Abstract

  REVEAL (the Registry to Evaluate Early and Long-term Pulmonary Arterial Hypertension Disease Management) is the largest US cohort of patients with pulmonary arterial hypertension (PAH) confirmed by right-sided heart catheterization (RHC), providing a more comprehensive subgroup characterization than previously possible. We used REVEAL to analyze the clinical features of patients with connective tissue disease-associated PAH (CTD-APAH).All newly and previously diagnosed patients with World Health Organization (WHO) group 1 PAH meeting RHC criteria at 54 US centers were consecutively enrolled. Cross-sectional and 1-year mortality and hospitalization analyses from time of enrollment compared CTD-APAH to idiopathic disease and systemic sclerosis (SSc) to systemic lupus erythematosus (SLE), mixed connective tissue disease (MCTD), and rheumatoid arthritis (RA).Compared with patients with idiopathic disease (n = 1,251), patients with CTD-APAH (n = 641) had better hemodynamics and favorable right ventricular echocardiographic findings but a higher prevalence of pericardial effusions, lower 6-min walk distance (300.5 ± 118.0 vs 329.4 ± 134.7 m, P = .01), higher B-type natriuretic peptide (BNP) levels (432.8 ± 789.1 vs 245.6 ± 427.2 pg/mL, P < .0001), and lower diffusing capacity of carbon monoxide (Dlco) (44.9% ± 18.0% vs 63.6% ± 22.1% predicted, P < .0001). One-year survival and freedom from hospitalization were lower in the CTD-APAH group (86% vs 93%, P < .0001; 67% vs 73%, P = .03). Compared with patients with SSc-APAH (n = 399), those with other CTDs (SLE, n = 110; MCTD, n = 52; RA, n = 28) had similar hemodynamics; however, patients with SSc-APAH had the highest BNP levels (552.2 ± 977.8 pg/mL), lowest Dlco (41.2% ± 16.3% predicted), and poorest 1-year survival (82% vs 94% in SLE-APAH, 88% in MCTD-APAH, and 96% in RA-APAH).Patients with SSc-APAH demonstrate a unique phenotype with the highest BNP levels, lowest Dlco, and poorest survival of all CTD-APAH subgroups.ClinicalTrials.gov; No.: NCT00370214; URL: clinicaltrials.gov.

  View details for DOI 10.1378/chest.10-0260

  View details for Web of Science ID 000285494000017

  View details for PubMedID 20507945

  View details for PubMedCentralID PMC3621419

• Bronchial blood supply after lung transplantation without bronchial artery revascularization CURRENT OPINION IN ORGAN TRANSPLANTATION Nicolls, M. R., Zamora, M. R. 2010; 15 (5): 563-567

  Abstract

  This review discusses how the bronchial artery circulation is interrupted following lung transplantation and what may be the long-term complications of compromising systemic blood flow to allograft airways.Preclinical and clinical studies have shown that the loss of airway microcirculations is highly associated with the development of airway hypoxia and an increased susceptibility to chronic rejection.The bronchial artery circulation has been highly conserved through evolution. Current evidence suggests that the failure to routinely perform bronchial artery revascularization at the time of lung transplantation may predispose patients to develop the bronchiolitis obliterans syndrome.

  View details for DOI 10.1097/MOT.0b013e32833deca9

  View details for Web of Science ID 000281837400004

  View details for PubMedID 20689435

  View details for PubMedCentralID PMC3034362

• Lung Transplant Airway Hypoxia A Diathesis to Fibrosis? AMERICAN JOURNAL OF RESPIRATORY AND CRITICAL CARE MEDICINE Dhillon, G. S., Zamora, M. R., Roos, J. E., Sheahan, D., Sista, R. R., van der Starre, P., Weill, D., Nicolls, M. R. 2010; 182 (2): 230-236

  Abstract

  Chronic rejection, manifested pathologically as airway fibrosis, is the major problem limiting long-term survival in lung transplant recipients. Airway hypoxia and ischemia, resulting from a failure to restore the bronchial artery (BA) circulation at the time of transplantation, may predispose patients to chronic rejection. To address this possibility, clinical information is needed describing the status of lung perfusion and airway oxygenation after transplantation.To determine the relative pulmonary arterial blood flow, airway tissue oxygenation and BA anatomy in the transplanted lung was compared with the contralateral native lung in lung allograft recipients.Routine perfusion scans were evaluated at 3 and 12 months after transplantation in 15 single transplant recipients. Next, airway tissue oximetry was performed in 12 patients during surveillance bronchoscopies in the first year after transplant and in 4 control subjects. Finally, computed tomography (CT)-angiography studies on 11 recipients were reconstructed to evaluate the post-transplant anatomy of the BAs.By 3 months after transplantation, deoxygenated pulmonary arterial blood is shunted away from the native lung to the transplanted lung. In the first year, healthy lung transplant recipients exhibit significant airway hypoxia distal to the graft anastomosis. CT-angiography studies demonstrate that BAs are abbreviated, generally stopping at or before the anastomosis, in transplant airways.Despite pulmonary artery blood being shunted to transplanted lungs after transplantation, grafts are hypoxic compared with both native (diseased) and control airways. Airway hypoxia may be due to the lack of radiologically demonstrable BAs after lung transplantation.

  View details for DOI 10.1164/rccm.200910-1573OC

  View details for Web of Science ID 000280206700014

  View details for PubMedID 20339145

  View details for PubMedCentralID PMC3269232

• Glycan expression profile in freshly isolated pancreatic islets Fontaine, M. J., Kvezereli, M., Nicolls, M. R., Wang, D. ASSOC CLINICAL SCIENTISTS. 2010: 188

  View details for Web of Science ID 000277043100027

• The Role Of T Cell Subsets In Tissue Perfusion And Oxygenation In Murine Orthotopic Tracheal Transplant Model Of Airway Allograft Rejection Khan, M. A., Jiang, X., Nicolls, M. R. AMER THORACIC SOC. 2010

  View details for Web of Science ID 000208771000094

• Refining Definitions Of Time To Clinical Worsening In Connective Tissue Disease Associated Pulmonary Arterial Hypertension Zamanian, R. T., Chung, L., Parsons, L., Miller, D. P., Safdar, Z., McGoon, M. D., Hassoun, P. M., Nicolls, M. R., Frost, A. AMER THORACIC SOC. 2010

  View details for Web of Science ID 000208771001425

• The Role of Complement Activation on Tissue Perfusion and Oxygenation in Airway Allograft Rejection Khan, M. A., Tomlinson, S., Xinguo, J., Nicolls, M. R. WILEY-BLACKWELL PUBLISHING, INC. 2010: 4

  View details for Web of Science ID 000273654600015

• HIF1 alpha And The Repair Of Injured Airway Microvasculature By Recipient- derived Tie2(+) Cells Jiang, X., Natarajan, R., Khan, M. A., Krasnow, M., Semenza, G., Nicolls, M. R. AMER THORACIC SOC. 2010

  View details for Web of Science ID 000208771000082

• Immune Reconstitution Prevents Autoimmune Inflammation and Right Ventricular Remodeling in Immunodeficiency-Associated Pulmonary Hypertension 82nd National Conference and Exhibitions and Scientific Sessions of the American-Heart-Association Tamosiuniene, R., Long, C., Ambler, K., Sung, Y., Gera, L., Wang, L., Nicolls, M. LIPPINCOTT WILLIAMS & WILKINS. 2009: S1135–S1135

  View details for Web of Science ID 000271831504181

• Prevention of Adverse Right Ventricular Remodeling and Autoimmune Inflammation after Splenocyte Therapy in Pulmonary Hypertension: Contribution of HOX11+, C-kit+, FOXP3+Cells 9th Annual Meeting of the Federation-of-Clinical-Immunology-Societies Tamosiuniene, R., Long, C., Ambler, K., Wang, L., Gera, L., Sung, Y., Nicolls, M. ACADEMIC PRESS INC ELSEVIER SCIENCE. 2009: S69–S70

  View details for DOI 10.1016/j.clim.2009.03.203

  View details for Web of Science ID 000266342300196

• Murine gamma Herpesvirus-68 Infection Induces Pulmonary Vascular Disease in S100A4 Overexpressing Mice Associated with Susceptibility of Elastic Fibers to Degradation and Altered microRNA Expression. Kim, Y., Alvira, C., Wang, L., Rabinovitch, M. AMER THORACIC SOC. 2009

  View details for Web of Science ID 000208733100815

• Restoration of Regulatory T Cells (Tregs) Prevents Autoimmune Inflammation (AI) and Pulmonary Hypertension (PH) in Rats Wang, L., Tamosiuniene, R., Voelkel, N., Gera, L., Nicolls, M. AMER THORACIC SOC. 2009

  View details for Web of Science ID 000208733101474

• Increased regulatory and decreased CD8+ cytotoxic T cells in the blood of patients with idiopathic pulmonary arterial hypertension RESPIRATION Ulrich, S., Nicolls, M. R., Taraseviciene, L., Speich, R., Voelkel, N. 2008; 75 (3): 272-280

  Abstract

  An association between pulmonary arterial hypertension (PAH) and various immune disorders is well established. Recently, the role of an intact immune system in protecting against pulmonary angioproliferation was shown in an animal model.To elucidate the role of T cells in human PAH, we comparatively studied T cell subclasses with emphasis on regulatory T cells (T(reg)) in the peripheral blood of patients with idiopathic pulmonary arterial hypertension (IPAH) and healthy controls.Isolated peripheral blood mononuclear cells from 36 patients diagnosed with IPAH and 33 healthy controls were stained with fluorescently labeled monoclonal antibodies against superficial T cell markers (CD3, CD4, CD8, CD25) and FoxP3, the intracellular marker of T(reg) cells. The relative cell distribution was analyzed by flow cytometry. The functionality of patient and control T(reg) cells was assessed by coculture of T(reg) with nonregulatory T cells from the same individual.Significantly less CD8+ T cells (p = 0.02) and more CD25hi+ and FoxP3+CD4+ T cells were found in the peripheral blood of patients compared with controls (p = 0.009 and p < 0.001, respectively). The percentage of FoxP3+ cells within the CD25hi+CD4+ T(reg) cells was similar. T(reg) cell functionality was equal in patients and controls.Our findings of decreased CD8+ T cells and increased T(reg) cells in the peripheral blood of patients with IPAH are novel and may have implications for directing future research in the field to elucidate the differential role of T cells and the immune system in IPAH.

  View details for DOI 10.1159/000111548

  View details for Web of Science ID 000255895400006

  View details for PubMedID 18025812

• Microvascular destruction identifies murine allografts that cannot be rescued from airway fibrosis JOURNAL OF CLINICAL INVESTIGATION Babu, A. N., Murakawa, T., Thurman, J. M., Miller, E. J., Henson, P. M., Zamora, M. R., Voelkel, N. F., Nicolls, M. R. 2007; 117 (12): 3774-3785

  Abstract

  Small airway fibrosis (bronchiolitis obliterans syndrome) is the primary obstacle to long-term survival following lung transplantation. Here, we show the importance of functional microvasculature in the prevention of epithelial loss and fibrosis due to rejection and for the first time, relate allograft microvascular injury and loss of tissue perfusion to immunotherapy-resistant rejection. To explore the role of alloimmune rejection and airway ischemia in the development of fibroproliferation, we used a murine orthotopic tracheal transplant model. We determined that transplants were reperfused by connection of recipient vessels to donor vessels at the surgical anastomosis site. Microcirculation through the newly formed vascular anastomoses appeared partially dependent on VEGFR2 and CXCR2 pathways. In the absence of immunosuppression, the microvasculature in rejecting allografts exhibited vascular complement deposition, diminished endothelial CD31 expression, and absent perfusion prior to the onset of fibroproliferation. Rejecting grafts with extensive endothelial cell injury were refractory to immunotherapy. After early microvascular loss, neovascularization was eventually observed in the membranous trachea, indicating a reestablishment of graft perfusion in established fibrosis. One implication of this study is that bronchial artery revascularization at the time of lung transplantation may decrease the risk of subsequent airway fibrosis.

  View details for DOI 10.1172/JCI32311

  View details for Web of Science ID 000251396600026

  View details for PubMedID 18060031

• Endogenous signals released from necrotic cells augment inflammatory responses to bacterial endotoxin IMMUNOLOGY LETTERS El Mezayen, R., El Gazzar, M., Seeds, M. C., McCall, C. E., Dreskin, S. C., Nicolls, M. R. 2007; 111 (1): 36-44

  Abstract

  Stressed cells undergoing necrosis release molecules that acts as endogenous danger signals to alert and activate innate immune cells. Both HMGB1 and HSP70 are induced in activated monocytes/macrophages and also are released from stressed or injured cells. We investigated whether HMGB1 and HSP70 released from necrotic monocytes/macrophages, can act as danger signals to mediate proinflammatory cytokine responses to bacterial endotoxin or lipopolysaccharide (LPS). We show that cell lysate, obtained from necrotic cells directly stimulates the proinflammatory cytokine and chemokine responses in human monocyte/macrophage cell line, THP-1, as revealed by the induction of TNF-alpha, IL-6 and IL-8 mRNA expression and protein production. In the presence of LPS, necrotic cell lysate induced a more robust increase in all three proteins. We found that HMGB1 and HSP70 were indeed present in the necrotic cell lysate and were responsible for the significant induction of the proinflammatory cytokine expression, as neutralization with antibodies against both proteins blocked the increase in the cytokine production seen after incubating LPS-stimulated cells with the necrotic cell lysate. We also found that the newly identified triggering receptor expressed on myeloid cells-1 (TREM-1) was involved in mediating the HMGB1- and HSP70-induced cytokine production. Blocking TREM-1 on THP-1 cells with a recombinant chimera prevented the increase in cytokine production, while simultaneous blocking of TLR4 and TREM-1 completely abolished the proinflammatory response, suggesting that TREM-1 synergizes with TLR4 to mediate the effects of such signals from necrotic cells. In addition, blocking HMGB1 or HSP70 simultaneously with TREM-1 did not decrease the cytokine level further, confirming the involvement of TREM-1 in mediating the effect of HMGB1 and HSP70. Although the interaction of HMGB1 and HSP70 with TREM-1 induced I kappa B alpha and p38 expression, both of which are required for the inflammatory cytokine expression, blockade of TREM-1 did not affect I kappa B alpha expression but markedly reduced p38 activation, as revealed by Western blot analysis. Together, these results demonstrate that HMGB1 and HSP70 released from necrotic cells function as endogenous danger signals to augment the proinflammatory responses in monocytes/macrophage and that TREM-1 relays such signals to the cytokine expression cascade. This mechanism may contribute to the amplification and persistence of the inflammatory response to bacterial infection.

  View details for DOI 10.1016/j.imlet.2007.04.011

  View details for Web of Science ID 000248672100006

  View details for PubMedID 17568691

• Oxidant stress, immune dysregulation, and vascular function in type I diabetes ANTIOXIDANTS & REDOX SIGNALING Nicolls, M. R., Haskins, K., Flores, S. C. 2007; 9 (7): 879-889

  Abstract

  Although high glucose is an important contributor to diabetic vasculopathies, complications still occur in spite of tight glycemic control, suggesting that some critical event prior to or concurrent with hyperglycemia may contribute to early vascular changes. Utilizing previously published and new experimental evidence, this review will discuss how prior to the hyperglycemic state, an imbalance between oxidants and antioxidants may contribute to early vascular dysfunction and set in motion proinflammatory insults that are further amplified as the diabetes develops. This imbalance results from the resetting of the equilibrium between vessel superoxide/H(2)O(2) production and/or decreased antioxidant defenses. Such an imbalance may cause endothelial dysfunction, characterized by abnormal endothelium-dependent vasoreactivity, as the first sign of blood vessel damage, followed by morphological changes of the vessel wall and inflammation. As such, increased oxidant stress in preglycemic states may be a critically central initiating event that underlies the pathogenesis of life-threatening vascular diseases in autoimmune diabetes. This review focuses on the relationship between oxidative stress, immune dysregulation, and vascular injury in type 1 diabetes, and how the discovery of novel pathways of vascular disease in nonobese diabetic mice may direct future studies in patients with type 1 diabetes.

  View details for DOI 10.1089/ars.2007.1631

  View details for Web of Science ID 000246646200009

  View details for PubMedID 17508913

• Hypoxia and the lung: Beyond hypoxic vasoconstriction Workshop on From Oxygen Sensing to Heart Failure Nicolls, M. R., Voelkel, N. F. MARY ANN LIEBERT INC. 2007: 741–43

  Abstract

  This article extends the influence and effects of hypoxia on the lung beyond vasoconstriction and regional blood flow control. Clearly, hypoxia, via the transcription factor hypoxia-inducible factor (HIF)-1alpha, induces a large number of genes encoding proteins, which control cellular metabolism and growth and also participate in inflammation. Hypoxia, likely via vascular endothelial growth factor (VEGF), recruits bone marrow precursor cells to the lung and affects the behavior of immune cells. How hypoxia shapes immune responses through VEGF and its receptors on mast cells, eosinophils, and dendritic cells and through lung endothelial cell/lymphocyte interactions will be a productive area for future research.

  View details for DOI 10.1089/ars.2007.1574

  View details for Web of Science ID 000246646000011

  View details for PubMedID 17511589

• Transfer of allograft specific tolerance requires CD4(+)CD25(+)T cells but not interleukin-4 or transforming growth factor-beta and cannot induce tolerance to linked antigens TRANSPLANTATION Hall, B. M., Plain, K. M., Verma, N. D., Tran, G. T., Boyd, R., Robinson, C. M., Nicolls, M. R., Berger, M. E., Nomura, M., Hodgkinson, S. J. 2007; 83 (8): 1075-1084

  Abstract

  The mechanisms by which CD4+T cells, especially CD4+ CD25+T cells, transfer allograft specific tolerance are poorly defined. The role of cytokines and the effect on antigen-presenting cells is not resolved.Anti-CD3 monoclonal antibody (mAb) therapy induced tolerance to PVG heterotopic cardiac transplantation in DA rats. Peripheral CD4+T cells or CD4+ CD25+ and CD4+ CD25-T cell subsets were adoptively transferred to irradiated DA hosts grafted with PVG heart grafts. For specificity studies, tolerant CD4+T cells were transferred to hosts with Lewis or (PVGxLewis)F1 heart grafts. Cytokine mRNA induction and the requirement for interleukin (IL)-4 and transforming growth factor (TGF)-beta in the transfer of tolerance was assessed.CD4+T cells transferred specific tolerance and suppressed naïve CD4+T cells capacity to effect rejection of PVG but not Lewis grafts. (PVGxLewis)F1 grafts had a major rejection episode but recovered. Later these hosts accepted PVG but not Lewis skin grafts. Adoptive hosts restored with tolerant or naïve cells had similar levels of mRNA expression for all Th1 and Th2 cytokines and effector molecules assayed. Transfer of tolerance by CD4+T cells was not blocked by mAb to IL-4 or TGF-beta. CD4+ CD25-T cells from either naïve or tolerant hosts effected rejection. In contrast neither tolerant nor naïve CD4+ CD25+T cells restored rejection.Specific tolerance transfer required CD4+ containing CD4+ CD25+T cells. An inflammatory response with induction of mRNA for Th1 and Th2 cytokines plus cytotoxic effector molecules occurred, but IL-4 and TGF-beta were not essential. Inhibition of antigen presenting cells was not the sole mechanism as there was no linked tolerance.

  View details for DOI 10.1097/01.tp.0000259553.66185.2f

  View details for Web of Science ID 000246234800012

  View details for PubMedID 17452898

• Thymoquinone attenuates proinflammatory responses in lipopolysaccharide-activated mast cells by modulating NF-kappaB nuclear transactivation BIOCHIMICA ET BIOPHYSICA ACTA-GENERAL SUBJECTS El Gazzar, M. A., El Mezayen, R., Nicolls, M. R., Dreskin, S. C. 2007; 1770 (4): 556-564

  Abstract

  Activated mast cells play an important role in the development and maintenance of chronic inflammation by releasing proinflammatory cytokines such as Tumor necrosis factor alpha (TNFalpha). TNFalpha is a key mediator of immune and inflammatory responses as it controls the expression of inflammatory genes network and its overproduction contributes significantly to the pathological complications observed in many inflammatory diseases. We have previously shown that thymoquinone (TQ), which has broad anti-inflammatory activities, attenuates allergic inflammation in mice. In the present study, we investigated the effect of TQ on LPS-induced TNFalpha production in the rat basophil cell line, RBL-2H3. Stimulation of RBL-2H3 cells with LPS markedly increased TNFalpha production. TQ treatment significantly inhibited LPS-induced TNFalpha mRNA expression and protein production. To understand the mechanism by which TQ inhibited TNFalpha production, we examined its effects on activation of NF-kappaB transcription factor, which has been shown to be involved in regulating TNFalpha responses. LPS activated the NF-kappaB pathway, resulting in accumulation of NF-kappaB p65 and p50 subunits in the nucleus and activation of TNFalpha promoter. TQ administration to LPS-stimulated cells did not noticeably alter NF-kappaB cytosolic activation or nuclear expression as demonstrated by western blot analysis. Instead, TQ significantly increased the amount of the repressive NF-kappaB p50 homodimer, and simultaneously decreased the amount of transactivating NF-kappaB p65:p50 heterodimer, bound to the TNFalpha promoter as revealed by electrophoretic mobility shift and chromatin immunoprecipitation assays. Transient transfection of RBL-2H3 cells with TNFalpha promoter-driven luciferase gene constructs demonstrated that one of the three NF-kappaB binding sites in the TNFalpha promoter, the kappaB3 site, played a major role in the induction of TNFalpha promoter-driven luciferase gene expression by LPS, as well as in mediating the inhibitory effects of TQ on TNFalpha production, as TQ had minimal effect on the TNFalpha promoter-luciferase construct that lacks the kappaB3 site. Together, these results suggest that TQ attenuates the proinflammatory response in LPS-stimulated mast cells by modulating nuclear transactivation of NF-kappaB and TNFalpha production.

  View details for DOI 10.1016/j.bbagen.2007.01.002

  View details for Web of Science ID 000245165900007

  View details for PubMedID 17292554

• The matrix comes to lung transplantation TRANSPLANTATION Babu, A. N., Nicolls, M. R. 2007; 83 (6): 683-684

  Abstract

  Lung transplantation is complicated by fibroproliferation, which is likely mediated in part by matrix metalloproteinases (MMPs) and tissue inhibitors of MMPs. This commentary briefly discusses what is known about these mediators in fibrotic pulmonary diseases and how an important new study by Yoshida and colleagues sheds light on the diverse functions of these proteins in alloimmune inflammation.

  View details for DOI 10.1097/01.tp.0000258596.27071.69

  View details for Web of Science ID 000245411400006

  View details for PubMedID 17414698

• Angiogenesis in chronic lung disease CHEST Voelkel, N. F., Douglas, I. S., Nicolls, M. 2007; 131 (3): 874-879

  Abstract

  Chronic lung diseases like COPD, severe progressive pulmonary hypertension (PH), and interstitial lung diseases all have a lung vascular disease component. Cellular and molecular mechanisms of pulmonary vascular remodeling have been experimentally explored in many animal models, and it is now clear that microvessels are involved. In emphysema patients, there is a loss of lung microvessels, and in many forms of severe PH there is obliteration of precapillary arterioles by angioproliferation. Thus, COPD/emphysema and severe angioproliferative PH are on the opposite ends of a spectrum of vascular biology responses. Animal experiments have provided insight regarding some of the initiating events that shape the various forms of pulmonary vascular remodeling. In pulmonary fibrosis and in the postinjury phase of acute lung injury, the angiogenic/angiostatic balance is also affected. This review will therefore discuss angiogenesis in several chronic lung diseases and will speculate on how altered vascular homeostasis may contribute to lung disease development.

  View details for DOI 10.1378/chest.06-2453

  View details for Web of Science ID 000245072900038

  View details for PubMedID 17356107

• Absence of T cells confers increased pulmonary arterial hypertension and vascular remodeling. Am J Respir Crit Care Med Nicolls MR*, Taraseviciene-Stewart L, Kraskauskas D, Scerbavicius R, Burns N, Cool C, Wood K, Parr JE, Boackle SA, Voelkel NF (*co-1st author) 2007; 175 (12): 1280-9
• Is alveolar destruction and emphysema in chronic obstructive pulmonary disease an immune disease? Proceedings of the American Thoracic Society Taraseviciene-Stewart, L., Douglas, I. S., Nana-Sinkam, P. S., Lee, J. D., Tuder, R. M., Nicolls, M. R., Voelkel, N. F. 2006; 3 (8): 687-690

  Abstract

  The alveolar destruction leading to airspace enlargement in patients with end-stage chronic obstructive pulmonary disease (COPD) is frequently progressive, despite smoking cessation. Several laboratories have accumulated data demonstrating the presence of immune cells in bronchial biopsy specimens and lung tissue sections from patients with COPD. Recently, the accumulation of T and B lymphocytes, often forming follicles, in the lung parenchyma from patients with severe COPD has been reported. In addition, it has been postulated that there might be an autoimmune component to COPD. T-cell receptor analysis has provided data consistent with the concept of T-cell clones in the lung tissue from patients with COPD. Against this background, we developed a model of autoimmune emphysema in adult rats. Based on published data showing that immunization of mice with human umbilical vein endothelial cells (HUVECs) causes production of anti-vascular endothelial growth factor (VEGF) receptor II (KDR) antibodies, and our own data indicating that administration of a VEGF receptor blocker in adult rats causes emphysema, we reasoned that intraperitoneal injection of HUVECs in rats would generate both anti-VEGF receptor antibodies and emphysema. Indeed, intraperitoneal injection of HUVECs caused emphysema. We further explored the autoimmune nature of this model, identified KDR antibodies in the serum of HUVEC-immunized rats, and injected serum from the emphysematous rats into naive rats and mice, which resulted in emphysema. Presently, we are in the process of investigating whether cigarette smoke extract causes emphysema. We recently identified anti-endothelial cell antibodies in the serum of patients with end-stage emphysema.

  View details for PubMedID 17065374

• Critical pathways leading to obliterative bronchiolitis in lung allografts CURRENT OPINION IN ORGAN TRANSPLANTATION Babu, A. N., Nicolls, M. R. 2006; 11 (5): 483-489

  View details for Web of Science ID 000241448000002

• Mechanisms of autoimmune emphysema. Proceedings of the American Thoracic Society Taraseviciene-Stewart, L., Burns, N., Kraskauskas, D., Nicolls, M. R., Tuder, R. M., Voelkel, N. F. 2006; 3 (6): 486-487

  View details for PubMedID 16921121

• Effect of thymoquinone on cyclooxygenase expression and prostaglandin production in a mouse model of allergic airway inflammation IMMUNOLOGY LETTERS El Mezayen, R., El Gazzar, M., Nicolls, M. R., Marecki, J. C., Dreskin, S. C., Nomiyama, H. 2006; 106 (1): 72-81

  Abstract

  Prostaglandins (PGs) are potent proinflammatory mediators generated through arachidonic acid metabolism by cyclooxygenase-1 and -2 (COX-1 and COX-2) in response to different stimuli and play an important role in modulating the inflammatory responses in a number of conditions, including allergic airway inflammation. Thymoquinone (TQ) is the main active constituent of the volatile oil extract of Nigella sativa seeds and has been reported to have anti-inflammatory properties. We examined the effect of TQ on the in vivo production of PGs and lung inflammation in a mouse model of allergic airway inflammation. Mice sensitized and challenged through the airways with ovalbumin (OVA) exhibited a significant increase in PGD2 and PGE2 production in the airways. The inflammatory response was characterized by an increase in the inflammatory cell numbers and Th2 cytokine levels in the bronchoalveolar lavage (BAL) fluid, lung airway eosinophilia and goblet cell hyperplasia, as well as the induction of COX-2 protein expression in the lung. Intraperitoneal injection of TQ for 5 days before the first OVA challenge attenuated airway inflammation as demonstrated by the significant decrease in Th2 cytokines, lung eosinophilia, and goblet cell hyperplasia. This attenuation of airway inflammation was concomitant to the inhibition of COX-2 protein expression and PGD2 production. However, TQ had a slight inhibitory effect on COX-1 expression and PGE2 production. These findings suggest that TQ has an anti-inflammatory effect during the allergic response in the lung through the inhibition of PGD2 synthesis and Th2-driven immune response.

  View details for DOI 10.1016/j.imlet.2006.04.012

  View details for Web of Science ID 000239978400011

  View details for PubMedID 16762422

• Downregulation of leukotriene biosynthesis by thymoquinone attenuates airway inflammation in a mouse model of allergic asthma BIOCHIMICA ET BIOPHYSICA ACTA-GENERAL SUBJECTS El Gazzar, M., El Mezayen, R., Nicolls, M. R., Marecki, J. C., Dreskin, S. C. 2006; 1760 (7): 1088-1095

  Abstract

  Chronic airway inflammation is a key feature of bronchial asthma. Leukotrienes are potent inflammatory mediators that play a role in the pathophysiology of asthma, and their levels are elevated in the airways in response to allergen challenge. We examined the anti-inflammatory effect of thymoquinone (TQ), the active principle in the volatile oil of Nigella sativa seeds, on leukotriene (LT) biosynthesis in a mouse model of allergic asthma. Mice sensitized and challenged with ovalbumin (OVA) antigen had an increased amounts of leukotriene B4 and C4, Th2 cytokines, and eosinophils in bronchoalveolar lavage (BAL) fluid. In addition, there was also a marked increase in lung tissue eosinophilia and goblet cell numbers. Administration of TQ before OVA challenge inhibited 5-lipoxygenase, the main enzyme in leukotriene biosynthesis, expression by lung cells and significantly reduced the levels of LTB4 and LTC4. This was accompanied by a marked decrease in Th2 cytokines and BAL fluid and lung tissue eosinophilia, all of which are characteristics of airway inflammation. These results demonstrate the anti-inflammatory effect of TQ in experimental asthma.

  View details for DOI 10.1016/j.bbagen.2006.03.006

  View details for Web of Science ID 000239040700013

  View details for PubMedID 16624488

• Anti-inflammatory effect of thymoquinone in a mouse model of allergic lung inflammation INTERNATIONAL IMMUNOPHARMACOLOGY El Gazzar, M., El Mezayen, R., Marecki, J. C., Nicolls, M. R., Canastar, A., Dreskin, S. C. 2006; 6 (7): 1135-1142

  Abstract

  Thymoquinone (TQ), the main active constituent of the volatile oil extracted from Nigella sativa's seeds, has been reported to have an anti-inflammatory and immune stimulatory effect on bronchial asthma and inflammation. However, little is known about the factors and mechanisms underlying these effects. In the present study, we examined the effect of TQ on airway inflammation in a mouse model of allergic asthma. Intraperitoneal injection of TQ before airway challenge of ovalbumin (OVA)-sensitized mice resulted in a marked decrease in lung eosinophilia and the elevated Th2 cytokines observed after airway challenge with OVA antigen; both in vivo, in the bronchoalveolar lavage (BAL) fluid and in vitro, following stimulation of lung cells with OVA. TQ also decreased the elevated serum levels of OVA-specific IgE and IgG1. Histological examination of lung tissue demonstrated that TQ significantly inhibited allergen-induced lung eosinophilic inflammation and mucus-producing goblet cells. While TQ showed a significant effect in inhibiting IL-4, IL-5 and IL-13 and some effect in inducing IFN-gamma production in the BAL fluid, it did show a slight effect on in vitro production of IL-4 by cultured lung cells stimulated with OVA antigen. These data suggest that TQ attenuates allergic airway inflammation by inhibiting Th2 cytokines and eosinophil infiltration into the airways; thus demonstrating its potential anti-inflammatory role during the allergic response in the lung.

  View details for DOI 10.1016/j.intimp.2006.02.004

  View details for Web of Science ID 000238155900012

  View details for PubMedID 16714217

• LFA-1 (CD11a) as a therapeutic target AMERICAN JOURNAL OF TRANSPLANTATION Nicolls, M. R., Gill, R. G. 2006; 6 (1): 27-36

  Abstract

  Leukocyte function associated antigen-1 (LFA-1) was one of the earliest of cell-surface molecules identified by monoclonal antibodies generated against leukocyte immunogens. This integrin heterodimer is perhaps best known as a classic adhesion molecule facilitating the interaction between T cells and antigen-presenting cells. However, varied studies indicate that LFA-1 has multi-faceted roles in the immune response including adhesion, activation and trafficking of leukocyte populations. While there has been long-standing interest in LFA-1 as a therapeutic target for regulating immunity, anti-LFA-1 therapy is still not a first-line indication for any clinical condition. Antagonism of LFA-1 with monoclonal antibodies, either alone or in combination with other agents, can result in regulatory tolerance in vivo. Furthermore, new generation humanized anti-LFA-1 monoclonal antibodies (Efalizumab) show at least modest promise for continued application in clinical trials. Thus, anti-LFA-1 forms a potential, but still largely unexploited, immunotherapy which may find its greatest application as an agent which augments other therapies.

  View details for DOI 10.1111/j.1600-6143.2005.01158.x

  View details for Web of Science ID 000234344900008

  View details for PubMedID 16433753

• Autoimmunity and pulmonary hypertension: a perspective EUROPEAN RESPIRATORY JOURNAL Nicolls, M. R., Taraseviciene-Stewart, L., Rai, P. R., Badesch, D. B., Voelkel, N. F. 2005; 26 (6): 1110-1118

  Abstract

  The association between autoimmunity and pulmonary arterial hypertension (PAH) has been appreciated for >40 yrs, but how autoimmune injury might contribute to the pathogenesis of this disease has only been examined in a case-specific manner. It is becoming increasingly clear that a variety of diverse clinical diseases, ranging from viral infections to connective tissue disorders, can culminate in pulmonary vascular pathology that is indistinguishable. Is there a hitherto unappreciated biology that unites these seemingly unrelated conditions? The answer to this question may come from the increasing body of evidence concerned with the central importance of regulatory T-cells in preventing inappropriate B-cell activity. Two striking similarities between conditions associated with severe angioproliferative pulmonary hypertension are a defect in the CD4 T-cell compartment and auto-antibody production. Pathogenic auto-antibodies targeting endothelial cells are capable of inducing vascular endothelial apoptosis and may initiate the development of PAH. The present review will focus on what is known about autoimmune phenomena in pulmonary arterial hypertension patients, in order to better consider whether an early loss of self-tolerance followed by autoimmune injury could influence the early development of severe angioproliferative pulmonary hypertension.

  View details for DOI 10.1183/09031936.05.00045705

  View details for Web of Science ID 000234203100023

  View details for PubMedID 16319344

• The protective role of T-lymphocytes in pulmonary vascular remodeling 47th Annual Thomas L Petty Aspen Lung Conference Taraseviciene-Stewart, L., Kraskauskas, D., Scerbavicins, R., Burns, N., Cool, C. D., Nicolls, M. R., Voelkel, N. F. AMER COLL CHEST PHYSICIANS. 2005: 571S–572S

  View details for Web of Science ID 000234371400012

  View details for PubMedID 16373829

• Type 2 diabetes mellitus as a conformational disease. JOP : Journal of the pancreas Hayden, M. R., Tyagi, S. C., Kerklo, M. M., Nicolls, M. R. 2005; 6 (4): 287-302

  Abstract

  Conformational diseases are conditions that arise from the dysfunctional aggregation of proteins in non-native conformations. Type 2 diabetes mellitus can be defined as a conformational disease because a constituent beta cell protein, islet amyloid polypeptide, undergoes a change in tertiary structure followed by self-association and tissue deposition. Type 2 diabetes mellitus is associated with multiple metabolic derangements that result in the excessive production of reactive oxygen species and oxidative stress. These reactive oxygen species set in motion a host of redox reactions which can result in unstable nitrogen and thiol species that contribute to additional redox stress. The ability of a cell to deal with reactive oxygen species and oxidative stress requires functional chaperones, antioxidant production, protein degradation and a cascade of intracellular events collectively known as the unfolded protein response. It is known that beta cells are particularly susceptible to perturbations in this quality control system and that reactive oxygen species play an important role in the development and/or progression of diabetes mellitus. Oxidative stress and increased insulin production contribute to endoplasmic reticulum stress, protein misfolding, and induction of the unfolded protein response. As the cell's quality control system becomes overwhelmed, conformational changes occur to islet amyloid polypeptide intermediates, generating stable oligomers with an anti-parallel crossed beta-pleated sheet structure that eventually accumulate as space-occupying lesions within the islets. By approaching type 2 diabetes mellitus as a conformational disease in which there is a structural transition from physiological protein to pathological protein, it is possible that the relentless nature of disease progression can be understood in relation to other conformational diseases.

  View details for PubMedID 16006679

• Chemokine-mediated angiogenesis: an essential link in the evolution of airway fibroses? JOURNAL OF CLINICAL INVESTIGATION Douglas, I. S., Nicolls, T. R. 2005; 115 (5): 1133-1136

  Abstract

  Angiogenesis may be an important factor in the development of fibrotic lung disease. Prior studies have strongly suggested a role for angiogenic vascular remodeling in pulmonary fibrosis, and emerging evidence indicates that new vessel formation is critical in airway fibrosis. Bronchiolitis obliterans syndrome is a fibrotic occlusion of distal airways that is largely responsible for the morbidity and mortality of patients after lung transplantation. In this issue, Belperio et al. demonstrate a role for CXC chemokine receptor 2 in the regulation of angiogenesis-mediated airway fibroproliferation. By integrating an understanding of neovascularization into the study of events that occur between inflammation and fibrosis, it becomes increasingly possible to rationally design therapies that can halt conditions of maladaptive fibrosis.

  View details for DOI 10.1172/JCI200525193

  View details for Web of Science ID 000228908300010

  View details for PubMedID 15864341

  View details for PubMedCentralID PMC1087192

• Simultaneous LFA-1 and CD40 ligand antagonism prevents airway remodeling in orthotopic airway transplantation: Implications for the role of respiratory epithelium as a modulator of fibrosis JOURNAL OF IMMUNOLOGY Murakawa, T., Kerklo, M. M., Zamora, M. R., Wei, Y., Gill, R. G., Henson, P. M., Grover, F. L., Nicolls, M. R. 2005; 174 (7): 3869-3879

  Abstract

  Airway remodeling is a prominent feature of certain immune-mediated lung diseases such as asthma and chronic lung transplant rejection. Under conditions of airway inflammation, the respiratory epithelium may serve an important role in this remodeling process. Given the proposed role of respiratory epithelium in nonspecific injury models, we investigated the respiratory epithelium in an immune-specific orthotopic airway transplant model. MHC-mismatched tracheal transplants in mice were used to generate alloimmune-mediated airway lesions. Attenuation of this immune injury and alteration of antidonor reactivity were achieved by the administration of combined anti-LFA-1/anti-CD40L mAbs. By contrast, without immunotherapy, transplanted airways remodeled with a flattening of respiratory epithelium and significant subepithelial fibrosis. Unopposed alloimmune injury for 10 days was associated with subsequent epithelial transformation and subepithelial fibrosis that could not be reversed with immunotherapy. The relining of donor airways with recipient-derived epithelium was delayed with immunotherapy resulting in partially chimeric airways by 28 days. Partial chimerism was sufficient to prevent luminal fibrosis. However, epithelial chimerism was also associated with airway remodeling. Therefore, there appears to be an intimate relationship between the morphology and level of chimerism of the respiratory epithelium and the degree of airway remodeling following alloimmune injury.

  View details for Web of Science ID 000228000100010

  View details for PubMedID 15778341

• An animal model of autoimmune emphysema AMERICAN JOURNAL OF RESPIRATORY AND CRITICAL CARE MEDICINE Taraseviciene-Stewart, L., Scerbavicius, R., Chloe, K. H., Moore, M., Sullivan, A., Nicolls, M. R., Fontenot, A. P., Tuder, R. M., Voelkel, N. F. 2005; 171 (7): 734-742

  Abstract

  Although cigarette smoking is implicated in the pathogenesis of emphysema, the precise mechanisms of chronic progressive alveolar septal destruction are not well understood. We show, in a novel animal model, that immunocompetent, but not athymic, nude rats injected intraperitoneally with xenogeneic endothelial cells (ECs) produce antibodies against ECs and develop emphysema. Immunization with ECs also leads to alveolar septal cell apoptosis and activation of matrix metalloproteases MMP-9 and MMP-2. Anti-EC antibodies cause EC apoptosis in vitro and emphysema in passively immunized mice. Moreover, immunization also causes accumulation of CD4+ T cells in the lung. Adoptive transfer of pathogenic, spleen-derived CD4+ cells into naive immunocompetent animal also results in emphysema. This study shows for the first time that humoral- and CD4+ cell-dependent mechanisms are sufficient to trigger the development of emphysema, suggesting that alveolar septal cell destruction might result from immune mechanisms.

  View details for DOI 10.1164/rccm.200409-127SOC

  View details for Web of Science ID 000228053000011

  View details for PubMedID 15563631

• Following universal prophylaxis with intravenous ganciclovir and cytomegalovirus immune globulin, valganciclovir is safe and effective for prevention of CMV infection following lung transplantation 4th Annual Meeting of the American-Transplant-Congress Zamora, M. R., Nicolls, M. R., Hodges, T. N., Marquesen, J., Astor, T., Grazia, T., Weill, D. WILEY-BLACKWELL. 2004: 1635–42

  Abstract

  We prospectively determined the safety and efficacy of valganciclovir for prevention of cytomegalovirus (CMV) in at-risk (donor positive/recipient negative [D+/R-] or R+) lung transplant recipients. We also determined the length of prophylaxis required to significantly decrease both CMV infection and disease. Consecutive lung transplant recipients surviving >30 days (n = 90) received combination prophylaxis with intravenous (i.v.) ganciclovir (GCV) 5 mg/kg/day and cytomegalovirus immune globulin (CMV-IVIG) followed by valganciclovir (450 mg twice-daily) to complete 180, 270 or 365 days of prophylaxis. This group was compared to a historical group (n = 140) who received high-dose oral acyclovir following i.v. GCV and CMV-IVIG. CMV disease was significantly lower in patients receiving valganciclovir compared to acyclovir (2.2% vs. 20%; p < 0.0001). Freedom from CMV infection and disease was significantly greater (p < 0.02) in patients receiving 180, 270 or 365 days of prophylaxis (90%, 95% and 90%, respectively) compared to those receiving 100-179 days (64%) or < 100 days (59%). No patient receiving valganciclovir died during the study. Following prophylaxis with i.v. GCV and CMV-IVIG, valganciclovir is safe and effective for prevention of CMV infection and disease in at-risk lung transplant recipients. The required length of prophylaxis was at least 180 days.

  View details for DOI 10.1111/j.1600-6143.2004.00571.x

  View details for Web of Science ID 000223862300010

  View details for PubMedID 15367218

• The Clinical and Biological Relationship between Type II Diabetes Mellitus and Alzheimer's Disease CURRENT ALZHEIMER RESEARCH Nicolls, M. R. 2004; 1 (1): 47-54

  Abstract

  The clinical relationship between Type II diabetes mellitus and Alzheimer's disease has been debated for over a decade. While several studies have not shown a clear clinical correlation, others have demonstrated that Type II diabetes is an independent risk factor for Alzheimer's disease. Why diabetes would increase the likelihood of Alzheimer's disease is not immediately clear, although recent studies have demonstrated an impact of insulin abnormalities, insulin resistance and advanced glycation end products on both the development of neural amyloid plaques and neurofibrillary tangles. Although endodermal in embryologic development, the pancreas is a highly innervated organ that shares a number of molecular similarities with brain at the level of the transcriptome and proteome. Type II diabetes and Alzheimer's disease are characterized by localized amyloid deposits that progress during the course of the disease. Comparing amyloid deposition in the brain and pancreas reveals some striking pathophysiologic similarities. Neurodegeneration in pancreatic islets, as manifested by neurofibrillary tangles, is less well studied than in Alzheimer's disease but may also occur. This review summarizes what is currently known about the clinical and biological relationships and similarities between Type II diabetes and Alzheimer's disease.

  View details for Web of Science ID 000207883200007

  View details for PubMedID 15975085

• Gene microarray study corroborates proteomic findings in rodent islet cells JOURNAL OF PROTEOME RESEARCH Cardozo, A. K., Berthou, L., Kruhoffer, M., Orntoft, T., Nicolls, M. R., Eizirik, D. L. 2003; 2 (5): 553-555

  Abstract

  As reported in an issue of Journal of Proteome Research, mass spectrometry has been used to identify numerous proteins in pancreatic islets. Our group studies beta cell gene expression, and we were interested in whether proteins described in this study could be found at the level of the transcriptome. Microarray analysis is a powerful technique for quantitative measurements of the expression of thousand genes in parallel. However, in crude tumor biopsies, only a subset of transcripts correlate with protein levels, and it is still unknown how frequently mRNA expression correlates with amount of protein in well-differentiated cells. To address this issue, we presently compared data from mouse primary islet proteins obtained by proteomic analysis with RNA data from FACS purified primary rat beta cells obtained by microarray analysis (Rasschaert J, Liu D, Cardozo AK, Kutlu B, Eizirik DL, manuscript in preparation).

  View details for DOI 10.1021/pr034029o

  View details for Web of Science ID 000186002600011

  View details for PubMedID 14582652

• Proteomics as a tool for discovery: Proteins implicated in Alzheimer's disease are highly expressed in normal pancreatic islets JOURNAL OF PROTEOME RESEARCH Nicolls, M. R., D'Antonio, J. M., Hutton, J. C., Gill, R. G., Czwornog, J. L., Duncan, M. W. 2003; 2 (2): 199-205

  Abstract

  A proteomic analysis of islets was undertaken to determine the protein constituents of normal adult mouse islets. Unexpectedly, we identified several islet proteins that are associated with the pathogenesis of Alzheimer's disease. Some of these proteins had chaperone activity that is integral to proper protein folding. This group includes GRP78, valosin-containing protein, calreticulin, protein disulfide isomerase, DnaK, HSP70, HSP60, and TCP-1. Additionally, neuronal proteins key to coordinated neuronal guidance and survival were also identified in islets. This group includes proprotein convertase subtilisin, collapsin response mediator protein 2, ubiquinol-cytochrome c reductase core protein, L-3-hydroxyacyl-Coenzyme A dehydrogenase, glutamine synthetase, peroxiredoxin, and secretogogin. An important subset of the proteins identified here has not been reported previously in pancreatic islets. Abnormal activity of these proteins in brain may contribute to the pathogenesis of Alzheimer's disease, a neurodegenerative condition characterized by focal amyloid deposits with neurofibrillary tangles. The putative role of these proteins in Alzheimer's pathogenesis is intriguing given the possible clinical relationship and pathological similarity of Alzheimer's disease to type 2 diabetes. These findings have therefore led to the hypothesis that these proteins may also play a role in type 2 diabetes.

  View details for DOI 10.1021/pr025576x

  View details for Web of Science ID 000182143500010

  View details for PubMedID 12716134

• CD4-dependent generation of dominant transplantation tolerance induced by simultaneous perturbation of CD154 and LFA-1 pathways JOURNAL OF IMMUNOLOGY Nicolls, M. R., Coulombe, M., Beilke, J., Gelhuas, H. C., Gill, R. G. 2002; 169 (9): 4831-4839

  Abstract

  CD154 and LFA-1 (CD11a) represent conceptually distinct pathways of receptor/ligand interactions (costimulation and adhesion/homing, respectively) that have been effectively targeted to induce long-term allograft acceptance and tolerance. In the current study, we determined the relative efficacy and nature of tolerance induced by mAbs specific for these pathways. In vitro analysis indicated that simultaneous targeting of CD154 and LFA-1 resulted in profound inhibition of alloreactivity, suggesting that combined anti-CD154/anti-LFA-1 therapy could be highly effective in vivo. Thus, we evaluated combining mAb therapies targeting CD154 and LFA-1 for inducing transplantation tolerance to pancreatic islet allografts. Monotherapy with either anti-CD154 or anti-LFA-1 was partially effective for inducing long-term allograft survival, whereas the combination resulted in uniform allograft acceptance in high-responder C57BL/6 recipients. This combined therapy was not lymphocyte depleting and did not require the long-term deletion of donor-reactive T lymphocytes to maintain allograft survival. Importantly, combined anti-CD154/anti-LFA therapy uniquely resulted in "dominant" transplantation tolerance. Therefore, simultaneous perturbation of CD154 and LFA-1 molecules can result in profound tolerance induction not accomplished through individual monotherapy approaches. Furthermore, results show that such regulatory tolerance can coexist with the presence of robust anti-donor reactivity, suggesting that active tolerance does not require a corresponding deletion of donor-reactive T cells. Interestingly, although the induction of this regulatory state was highly CD4 dependent, the adoptive transfer of tolerance was less CD4 dependent in vivo.

  View details for Web of Science ID 000178777400019

  View details for PubMedID 12391193

• Interferon-gamma is not a universal requirement for islet allograft survival TRANSPLANTATION Nicolls, M. R., Coulombe, M., Diamond, A. S., Beilke, J., Gill, R. G. 2002; 74 (4): 472-477

  Abstract

  Although many transplantation studies have implicated a graft-destructive role for T helper (Th)1 cytokines and a graft-protective role for Th2 cytokines, more recent studies have challenged this paradigm by showing that long-term allograft survival can actually require the presence of Th1 cytokines, such as interleukin 2 and interferon (IFN)-gamma. The purpose of this study was to examine the requirement for IFN-gamma in the induction of islet allograft acceptance after monoclonal antibody therapy targeting conceptually distinct molecular pathways: the costimulatory molecule CD154, the CD4 coreceptor, or the beta2 integrin lymphocyte function-associated antigen (LFA)-1 (CD11a).Diabetic C57Bl/6 (B6; H2b) mice were grafted with fully MHC mismatched BALB/c (H2d) islets, or reciprocally, diabetic BALB/c mice underwent transplantation with B6 islets and were treated with anti-CD154, anti-CD4, or anti-LFA-1.When IFN-gamma gene knockout mice were used as graft recipients, the requirement for IFN-gamma in allograft survival was found to be highly conditional, depending on both the host strain and the induction therapy used. In both strain combinations studied, anti-CD154 was effective in the presence or absence of IFN-gamma, whereas anti-CD4 lost therapeutic potential in the absence of this cytokine. Alternatively, the requirement for IFN-gamma for allograft prolongation by anti-LFA-1 therapy was noted only in B6 transplant recipients.IFN-gamma is not always requisite in islet allograft survival but rather varies according to the molecular target of induction therapy and the genetic background of the transplant recipient.

  View details for DOI 10.1097/01.TP.0000026310.54443.3E

  View details for Web of Science ID 000177808600007

  View details for PubMedID 12352904

• Reversal of experimental allergic encephalomyelitis with non-mitogenic, non-depleting anti-CD3 mAb therapy with a preferential effect on T(h)1 cells that is augmented by IL-4 INTERNATIONAL IMMUNOLOGY Tran, G. T., CARTER, N., He, X. Y., Spicer, T. S., Plain, K. M., Nicolls, M., Hall, B. M., Hodgkinson, S. J. 2001; 13 (9): 1109-1120

  Abstract

  This study examined whether therapy with a non-mitogenic, non-activating anti-CD3 mAb (G4.18) alone, or in combination with the T(h)2 cytokines, could inhibit induction or facilitate recovery from experimental allergic encephalomyelitis (EAE) in Lewis rats. G4.18, but not rIL-4, rIL-5 or anti-IL-4 mAb, reduced the severity and accelerated recovery from active EAE. A combination of rIL-4 with G4.18 was more effective than G4.18 alone. The infiltrate of CD4(+) and CD8(+) T cells, B cells, dendritic cells, and macrophages in the brain stem was less with combined G4.18 and IL-4 than G4.18 therapy or no treatment. Residual cells had preferential sparing of T(r)1 cytokines IL-5 and transforming growth factor-beta with loss of T(h)1 markers IL-2, IFN-gamma and IL-12Rbeta2, and the T(h)2 cytokine IL-4 as well as macrophage cytokines IL-10 and tumor necrosis factor-alpha. Lymph nodes draining the site of immunization had less mRNA for T(h)1 cytokines, but T(h)2 and T(r)1 cytokine expression was spared. Treatment with G4.18, rIL-4 or rIL-5 from the time of immunization had no effect on the course of active EAE. MRC OX-81, a mAb that blocks IL-4, delayed onset by 2 days, but had no effect on severity of active EAE. G4.18 also inhibited the ability of activated T cells from rats with active EAE to transfer passive EAE. This study demonstrated that T cell-mediated inflammation was rapidly reversed by a non-activating anti-CD3 mAb that blocked effector T(h)1 cells, and spared cells expressing T(h)2 and T(r)1 cytokines.

  View details for Web of Science ID 000171127200003

  View details for PubMedID 11526091

• The basis of immunogenicity of endocrine allografts 10th International Symposium on the Immunobiology of Proteins and Peptides Nicolls, M. R., Coulombe, M., Gill, R. G. BEGELL HOUSE INC. 2001: 87–101

  Abstract

  Two signals are required for optimal T-cell activation: the engagement of the antigen-specific receptor and the provision of a second non-antigen-specific inductive signal, or costimulator (CoS). Regarding allograft immunity, two primary pathways of donor antigen presentation can fulfill this two-signal requirement, resulting in cellular immunity to a transplant: (1) "direct" (donor MHC-restricted) presentation in which the antigen-presenting cells (APCs) resident within the transplant directly activate host T lymphocytes and (2) "indirect" (host MHC-restricted) presentation in which host-derived APCs acquire donor antigens that are then presented to host T lymphocytes. It appears that endocrine allografts, such as pancreatic islets and thyroid, are highly dependent on donor-derived APCs, or "passenger leukocytes," to trigger acute graft rejection. Tissue pretreatment aimed at selectively eliminating APCs within endocrine tissues can result in indefinite allograft survival in immune-competent recipients. Although such results implicate the "direct" pathway as the predominant route of host sensitization, the role of donor APCs in rejection appears to be more complex. Recently, we have found that indirect, CD4 T-cell-dependent reactivity can contribute to islet allograft rejection. However, such indirect recognition nevertheless requires donor-derived APCs as a source of antigen. Thus, whereas the donor-type APC is a critical limiting step for initiating islet allograft rejection, such cells can trigger both direct and indirect forms of immune responses that can result in graft rejection. That is, donor hematopoietic cells, rather than tissue parenchymal cells, probably play a major role in providing antigens that stimulate cellular immunity.

  View details for Web of Science ID 000171493400007

  View details for PubMedID 11642616

• Anti-LFA-1 therapy induces long-term islet allograft acceptance in the absence of IFN-gamma or IL-4 JOURNAL OF IMMUNOLOGY Nicolls, M. R., Coulombe, M., Yang, H., Bolwerk, A., Gill, R. G. 2000; 164 (7): 3627-3634

  Abstract

  mAb therapy directed against a variety of cell surface accessory molecules has been effectively utilized to prolong allograft acceptance in various models of tissue and organ transplantation. The purpose of this study was to determine whether transient therapy directed against the adhesion molecule LFA-1 (CD11a) was sufficient to induce donor-specific tolerance to pancreatic islet allografts. Anti-LFA-1 monotherapy was found to be efficacious in inducing long-term islet allograft acceptance in multiple donor-recipient strain combinations. Graft acceptance following anti-LFA-1 therapy was not simply due to clonal ignorance of donor Ags in that the majority of recipients bearing established islet allografts resisted rejection induced by immunization with donor-type APCs. Furthermore, donor-specific tolerance from anti-LFA-1-treated animals could be transferred to secondary immune-deficient animals. Taken together, these results indicated that transient anti-LFA-1 monotherapy resulted in donor-specific tolerance. In vitro, functionally tolerant animals retained normal anti-donor reactivity as assessed by proliferative, cytotoxic, and cytokine release assays that demonstrated that tolerance was not secondary to general clonal deletion or anergy of donor-reactive T cells. Finally, anti-LFA-1 treatment was effective in both IL-4-deficient and IFN-gamma-deficient recipients, indicating that neither of these cytokines are universally required for allograft acceptance. These results suggest that anti-adhesion-based therapy can induce a nondeletional form of tolerance that is not overtly dependent on the prototypic Th1 and Th2 cytokines, IFN-gamma and IL-4, respectively, in contrast to results in other transplantation models.

  View details for Web of Science ID 000086020700025

  View details for PubMedID 10725719

• Diffuse alveolar hemorrhage with underlying pulmonary capillaritis in the retinoic acid syndrome AMERICAN JOURNAL OF RESPIRATORY AND CRITICAL CARE MEDICINE Nicolls, M. R., Terada, L. S., Tuder, R. M., Prindiville, S. A., Schwarz, M. I. 1998; 158 (4): 1302-1305

  Abstract

  All-trans-retinoic acid (ATRA) can induce a clinical remission in patients with acute promyelocytic leukemia. An adverse condition called "retinoic acid syndrome" limits this therapy. It is characterized by fever and respiratory distress, along with weight gain, pleural or pericardial effusions, peripheral edema, thromboembolic events, and intermittent hypotension. The lung disease has been previously ascribed to an infiltration of leukemic or maturing myeloid cells into lung parenchyma, which is sometimes associated with pleural effusions and diffuse alveolar hemorrhage. We report a case of retinoic acid syndrome in an 18-yr-old woman who developed diffuse alveolar hemorrhage while being treated with ATRA for acute promyelocytic leukemia. An open lung biopsy revealed pulmonary capillaritis.

  View details for Web of Science ID 000076453300044

  View details for PubMedID 9769296

• Recognition and treatment of diffuse panbronchiolitis INFECTIONS IN MEDICINE Nicolls, M. R., Weiss, S. M., Schwarz, M. I. 1998; 15 (9): 657-662

  View details for Web of Science ID 000076097100019

• INDUCTION OF TOLERANCE TO HEART ALLOGRAFTS IN RATS USING POSTTRANSPLANT TOTAL LYMPHOID IRRADIATION AND ANTI-T CELL ANTIBODIES TRANSPLANTATION WOODLEY, S. L., Gurley, K. E., HOFFMANN, S. L., Nicolls, M. R., Hagberg, R., CLAYBERGER, C., Holm, B., Wang, X. G., Hall, B. M., Strober, S. 1993; 56 (6): 1443-1447

  Abstract

  This study examined whether posttransplant anti-T cell monoclonal or polyclonal antibody therapy could provide a window of treatment to allow posttransplant total lymphoid irradiation (TLI) to induce tolerance. These experiments were conducted in a high responder strain combination of an ACI cardiac allograft into a Lewis rat. In this situation, treatment with antibody or posttransplant TLI alone is insufficient to induce tolerance, while similar treatments alone have been shown to induce tolerance in low responder strains. The affects of three anti-T cell therapies were compared: anti-CD4 mAb therapy, anti-CD3 mAb, and rabbit antithymocyte globulin (RATG). None of these antibody therapies alone prolonged graft survival indefinitely. Combining anti-CD4 therapy with posttransplant TLI markedly delayed rejection but failed to induce long-term graft survival. Tolerance could be induced by a combination of anti-pan T cell antibody (anti-CD3) and TLI, and, all grafts survived beyond 100 days. RATG failed to prevent graft rejection when used alone or in combination with TLI. However, posttransplant therapy with a combination of RATG, TLI, and single-donor blood transfusion resulted in graft survival beyond 100 days. Recipients bearing long-term donor grafts rejected third-party (PVG) grafts within 2 weeks. Low density donor bone marrow cells used instead of a blood transfusion did not facilitate tolerance. The results indicate that monoclonal or polyclonal anti-pan T cell antibodies, TLI, and a donor blood cell infusion function synergistically in facilitating tolerance to allografts in the posttransplant period.

  View details for Web of Science ID A1993MQ05600031

  View details for PubMedID 8279017

• INDUCTION OF LONG-TERM SPECIFIC TOLERANCE TO ALLOGRAFTS IN RATS BY THERAPY WITH AN ANTI-CD3-LIKE MONOCLONAL-ANTIBODY TRANSPLANTATION Nicolls, M. R., AVERSA, G. G., Pearce, N. W., Spinelli, A., Berger, M. F., Gurley, K. E., Hall, B. M. 1993; 55 (3): 459-468

  Abstract

  Monoclonal antibodies to CD3 have been shown to activate T cells in vivo and in vitro but have also been shown to render T cells anergic in vitro. In this study G4.18, a mouse IgG3 mAb, was produced that appeared to recognize CD3 by its binding to all peripheral T cells, including a population not recognized by mAb to TCR-alpha/beta that was presumed to be TCR-gamma/delta cells. It precipitated molecules in the 24-26 kd region consistent with the CD3 complex as well as molecules approximately 45 and approximately 49 kd that corresponded to TCR alpha and beta chains and a 92-kd complex. Incubating T cells for 24 hr with saturating concentrations of G4.18 caused modulation of the TCR complex. In vitro, it activated T cells but only if prebound to plastic. In solution it inhibited MLC and CML, but not PHA or Con A activation. In vivo, G4.18 was not toxic even in high doses, and this was thought to be due to the inability of this mAb to activate T cells in vitro because the rat lacks Fc receptors for mouse IgG3. Therapy with G4.18 resulted in transient modulation of TCR/CD3 on T cells and depletion of these cells from blood. G4.18 had no depleting effects by lymph node or spleen cells but caused marked, transient thymic involution. Therapy with G4.18 also induced indefinite survival (> 100 days) of PVG (RTIc) heart grafts but not skin grafts in DA (RTIa) hosts. These hosts with long-surviving cardiac transplants, when grafted from PVG skin, accepted these grafts but rejected third-party skin in first-set. Thus G4.18 was shown to induce long-term specific tolerance to an organ allograft.

  View details for Web of Science ID A1993KT96100001

  View details for PubMedID 8456460

• ANTI-CD3 MONOCLONAL-ANTIBODY INDUCES TOLERANCE TO ALLOANTIGENS IN RATS NICOLLS, M. R., AVERSA, G. G., PEARCE, N. W., SPINELLI, A., BERGER, M. F., GURLEY, K. E., HALL, B. M. SLACK INC. 1991: A380

  View details for Web of Science ID A1991FH32301351

• ROLE OF T-CELLS IN HEYMANN NEPHRITIS QUIZA, C., GURLEY, K. E., SPINELLI, A., LEENAERTS, P., NICOLLS, M., HALL, B. M. SLACK INC. 1991: A340

  View details for Web of Science ID A1991FH32301127

• PANEL OF MONOCLONAL-ANTIBODIES DIRECTED AGAINST RAT T-LYMPHOCYTES NICOLLS, M. R., AVERSA, G. A., HALL, B. M. SLACK INC. 1990: A215

  View details for Web of Science ID A1990CF63601244