Honors & Awards


  • 2022 Research Prize, René Baumgart-Foundation, Leipzig, Germany (2022)
  • Young Investigator Award, Pulmonary Vascular Research Institute (PVRI), UK (2020)
  • Young Investigator Presentation, European Respiratory Society (ERS), Lisbon, Portugal (2016)
  • Abstract Scholarship Award, American Thoracic Society (ATS), San Diego, USA (2014)
  • Young Investigator Award, 5° World Symposium on Pulmonary Hypertension, Nice, France (2013)

Boards, Advisory Committees, Professional Organizations


  • Member, German Center for Lung Research (DZL) (2014 - Present)
  • Member, American Heart Association (2024 - Present)

Research Interests


  • Collaborative Learning
  • Research Methods
  • Science Education
  • Technology and Education

Current Research and Scholarly Interests


Epigenomics, Cardiovascular Inflammation, Exosomes, Biomarkers, Endothelial-Pericyte Communication

All Publications


  • Transcriptional profiling unveils molecular subgroups of adaptive and maladaptive right ventricular remodeling in pulmonary hypertension NATURE CARDIOVASCULAR RESEARCH Khassafi, F., Chelladurai, P., Valasarajan, C., Nayakanti, S., Martineau, S., Sommer, N., Yokokawa, T., Boucherat, O., Kamal, A., Kiely, D. G., Swift, A. J., Alabed, S., Omura, J., Breuils-Bonnet, S., Kuenne, C., Potus, F., Guenther, S., Savai, R., Seeger, W., Looso, M., Lawrie, A., Zaugg, J. B., Tello, K., Provencher, S., Bonnet, S., Pullamsetti, S. 2023; 2 (10): 917-+
  • Epigenetic reactivation of transcriptional programs orchestrating fetal lung development in human pulmonary hypertension. Science translational medicine Chelladurai, P., Kuenne, C., Bourgeois, A., Günther, S., Valasarajan, C., Cherian, A. V., Rottier, R. J., Romanet, C., Weigert, A., Boucherat, O., Eichstaedt, C. A., Ruppert, C., Guenther, A., Braun, T., Looso, M., Savai, R., Seeger, W., Bauer, U. M., Bonnet, S., Pullamsetti, S. S. 2022; 14 (648): eabe5407

    Abstract

    Phenotypic alterations in resident vascular cells contribute to the vascular remodeling process in diseases such as pulmonary (arterial) hypertension [P(A)H]. How the molecular interplay between transcriptional coactivators, transcription factors (TFs), and chromatin state alterations facilitate the maintenance of persistently activated cellular phenotypes that consequently aggravate vascular remodeling processes in PAH remains poorly explored. RNA sequencing (RNA-seq) in pulmonary artery fibroblasts (FBs) from adult human PAH and control lungs revealed 2460 differentially transcribed genes. Chromatin immunoprecipitation sequencing (ChIP-seq) revealed extensive differential distribution of transcriptionally accessible chromatin signatures, with 4152 active enhancers altered in PAH-FBs. Integrative analysis of RNA-seq and ChIP-seq data revealed that the transcriptional signatures for lung morphogenesis were epigenetically derepressed in PAH-FBs, including coexpression of T-box TF 4 (TBX4), TBX5, and SRY-box TF 9 (SOX9), which are involved in the early stages of lung development. These TFs were expressed in mouse fetuses and then repressed postnatally but were maintained in persistent PH of the newborn and reexpressed in adult PAH. Silencing of TBX4, TBX5, SOX9, or E1A-associated protein P300 (EP300) by RNA interference or small-molecule compounds regressed PAH phenotypes and mesenchymal signatures in arterial FBs and smooth muscle cells. Pharmacological inhibition of the P300/CREB-binding protein complex reduced the remodeling of distal pulmonary vessels, improved hemodynamics, and reversed established PAH in three rodent models in vivo, as well as reduced vascular remodeling in precision-cut tissue slices from human PAH lungs ex vivo. Epigenetic reactivation of TFs associated with lung development therefore underlies PAH pathogenesis, offering therapeutic opportunities.

    View details for DOI 10.1126/scitranslmed.abe5407

    View details for PubMedID 35675437

  • ATP citrate lyase drives vascular remodeling in systemic and pulmonary vascular diseases through metabolic and epigenetic changes SCIENCE TRANSLATIONAL MEDICINE Grobs, Y., Romanet, C., Lemay, S., Bourgeois, A., Voisine, P., Theberge, C., Sauvaget, M., Breuils-Bonnet, S., Martineau, S., El Kabbout, R., Valasarajan, C., Chelladurai, P., Pelletier, A., Mougin, M., Dumais, E., Perron, J., Flamand, N., Potus, F., Provencher, S., Pullamsetti, S., Boucherat, O., Bonnet, S. 2024; 16 (777)
  • GLI1+ Cells Contribute to Vascular Remodeling in Pulmonary Hypertension. Circulation research Chu, X., Kheirollahi, V., Lingampally, A., Chelladurai, P., Valasarajan, C., Vazquez-Armendariz, A. I., Hadzic, S., Khadim, A., Pak, O., Rivetti, S., Wilhelm, J., Bartkuhn, M., Crnkovic, S., Moiseenko, A., Heiner, M., Kraut, S., Atefi, L. S., Koepke, J., Valente, G., Ruppert, C., Braun, T., Samakovlis, C., Alexopoulos, I., Looso, M., Chao, C. M., Herold, S., Seeger, W., Kwapiszewska, G., Huang, X., Zhang, J. S., Pullamsetti, S. S., Weissmann, N., Li, X., El Agha, E., Bellusci, S. 2024; 134 (11): e133-e149

    Abstract

    The precise origin of newly formed ACTA2+ (alpha smooth muscle actin-positive) cells appearing in nonmuscularized vessels in the context of pulmonary hypertension is still debatable although it is believed that they predominantly derive from preexisting vascular smooth muscle cells (VSMCs).Gli1Cre-ERT2; tdTomatoflox mice were used to lineage trace GLI1+ (glioma-associated oncogene homolog 1-positive) cells in the context of pulmonary hypertension using 2 independent models of vascular remodeling and reverse remodeling: hypoxia and cigarette smoke exposure. Hemodynamic measurements, right ventricular hypertrophy assessment, flow cytometry, and histological analysis of thick lung sections followed by state-of-the-art 3-dimensional reconstruction and quantification using Imaris software were used to investigate the contribution of GLI1+ cells to neomuscularization of the pulmonary vasculature.The data show that GLI1+ cells are abundant around distal, nonmuscularized vessels during steady state, and this lineage contributes to around 50% of newly formed ACTA2+ cells around these normally nonmuscularized vessels. During reverse remodeling, cells derived from the GLI1+ lineage are largely cleared in parallel to the reversal of muscularization. Partial ablation of GLI1+ cells greatly prevented vascular remodeling in response to hypoxia and attenuated the increase in right ventricular systolic pressure and right heart hypertrophy. Single-cell RNA sequencing on sorted lineage-labeled GLI1+ cells revealed an Acta2high fraction of cells with pathways in cancer and MAPK (mitogen-activated protein kinase) signaling as potential players in reprogramming these cells during vascular remodeling. Analysis of human lung-derived material suggests that GLI1 signaling is overactivated in both group 1 and group 3 pulmonary hypertension and can promote proliferation and myogenic differentiation.Our data highlight GLI1+ cells as an alternative cellular source of VSMCs in pulmonary hypertension and suggest that these cells and the associated signaling pathways represent an important therapeutic target for further studies.

    View details for DOI 10.1161/CIRCRESAHA.123.323736

    View details for PubMedID 38639105

  • Restoration of Foxp3+ Regulatory T Cells by HDAC-Dependent Epigenetic Modulation Plays a Pivotal Role in Resolving Pulmonary Arterial Hypertension Pathology. American journal of respiratory and critical care medicine Chen, C. N., Hajji, N., Yeh, F. C., Rahman, S., Ali, S., Wharton, J., Baxan, N., Zhao, L., Xie, C. Y., Chen, Y. G., Frid, M. G., Chelladurai, P., Pullamsetti, S. S., Stenmark, K. R., Wilkins, M. R., Zhao, L. 2023; 208 (8): 879-895

    Abstract

    Rationale: Immune dysregulation is a common feature of pulmonary arterial hypertension (PAH). Histone deacetylase (HDAC)-dependent transcriptional reprogramming epigenetically modulates immune homeostasis and is a novel disease-oriented approach in modern times. Objectives: To identify a novel functional link between HDAC and regulatory T cells (Tregs) in PAH, aiming to establish disease-modified biomarkers and therapeutic targets. Methods: Peripheral blood mononuclear cells were isolated from patients with idiopathic PAH (IPAH) and rodent models of pulmonary hypertension (PH): monocrotaline rats, Sugen5416-hypoxia rats, and Treg-depleted mice. HDAC inhibitor vorinostat (suberoylanilide hydroxamic acid, SAHA) was used to examine the immune modulatory effects in vivo, ex vivo, and in vitro. Measurements and Main Results: Increased HDAC expression was associated with reduced Foxp3+ Tregs and increased PD-1 (programmed cell death-1) signaling in peripheral blood mononuclear cells from patients with IPAH. SAHA differentially modified a cluster of epigenetic-sensitive genes and induced Foxp3+ Treg conversion in IPAH T cells. Rodent models recapitulated these epigenetic aberrations and T-cell dysfunction. SAHA attenuated PH phenotypes and restored FOXP3 transcription and Tregs in PH rats; interestingly, the effects were more profound in female rats. Selective depletion of CD25+ Tregs in Sugen5416-hypoxia mice neutralized the effects of SAHA. Furthermore, SAHA inhibited endothelial cytokine/chemokine release upon stimulation and subsequent immune chemotaxis. Conclusions: Our results indicated HDAC aberration was associated with Foxp3+ Treg deficiency and demonstrated an epigenetic-mediated mechanism underlying immune dysfunction in PAH. Restoration of Foxp3+ Tregs by HDAC inhibitors is a promising approach to resolve pulmonary vascular pathology, highlighting the potential benefit of developing epigenetic therapies for PAH.

    View details for DOI 10.1164/rccm.202301-0181OC

    View details for PubMedID 37676930

  • Transcriptional profiling unveils molecular subgroups of adaptive and maladaptive right ventricular remodeling in pulmonary hypertension. Nature cardiovascular research Khassafi, F., Chelladurai, P., Valasarajan, C., Nayakanti, S. R., Martineau, S., Sommer, N., Yokokawa, T., Boucherat, O., Kamal, A., Kiely, D. G., Swift, A. J., Alabed, S., Omura, J., Breuils-Bonnet, S., Kuenne, C., Potus, F., Günther, S., Savai, R., Seeger, W., Looso, M., Lawrie, A., Zaugg, J. B., Tello, K., Provencher, S., Bonnet, S., Pullamsetti, S. S. 2023; 2 (10): 917-936

    Abstract

    Right ventricular (RV) function is critical to prognosis in all forms of pulmonary hypertension. Here we perform molecular phenotyping of RV remodeling by transcriptome analysis of RV tissue obtained from 40 individuals, and two animal models of RV dysfunction of both sexes. Our unsupervised clustering analysis identified 'early' and 'late' subgroups within compensated and decompensated states, characterized by the expression of distinct signaling pathways, while fatty acid metabolism and estrogen response appeared to underlie sex-specific differences in RV adaptation. The circulating levels of several extracellular matrix proteins deregulated in decompensated RV subgroups were assessed in two independent cohorts of individuals with pulmonary arterial hypertension, revealing that NID1, C1QTNF1 and CRTAC1 predicted the development of a maladaptive RV state, as defined by magnetic resonance imaging parameters, and were associated with worse clinical outcomes. Our study provides a resource for subphenotyping RV states, identifying state-specific biomarkers, and potential therapeutic targets for RV dysfunction.

    View details for DOI 10.1038/s44161-023-00338-3

    View details for PubMedID 39196250

    View details for PubMedCentralID 7887079

  • The HDAC2-SP1 Axis Orchestrates Protumor Macrophage Polarization. Cancer research Zheng, X., Sarode, P., Weigert, A., Turkowski, K., Chelladurai, P., Günther, S., Kuenne, C., Winter, H., Stenzinger, A., Reu, S., Grimminger, F., Stiewe, T., Seeger, W., Pullamsetti, S. S., Savai, R. 2023; 83 (14): 2345-2357

    Abstract

    Tumor-associated macrophages (TAM), including antitumor M1-like TAMs and protumor M2-like TAMs, are transcriptionally dynamic innate immune cells with diverse roles in lung cancer development. Epigenetic regulators are key in controlling macrophage fate in the heterogeneous tumor microenvironment. Here, we demonstrate that the spatial proximity of HDAC2-overexpressing M2-like TAMs to tumor cells significantly correlates with poor overall survival of lung cancer patients. Suppression of HDAC2 in TAMs altered macrophage phenotype, migration, and signaling pathways related to interleukins, chemokines, cytokines, and T-cell activation. In coculture systems of TAMs and cancer cells, suppressing HDAC2 in TAMs resulted in reduced proliferation and migration, increased apoptosis of cancer cell lines and primary lung cancer cells, and attenuated endothelial cell tube formation. HDAC2 regulated the M2-like TAM phenotype via acetylation of histone H3 and transcription factor SP1. Myeloid cell-specific deletion of Hdac2 and pharmacologic inhibition of class I HDACs in four different murine lung cancer models induced the switch from M2-like to M1-like TAMs, altered infiltration of CD4+ and CD8+ T cells, and reduced tumor growth and angiogenesis. TAM-specific HDAC2 expression may provide a biomarker for lung cancer stratification and a target for developing improved therapeutic approaches.HDAC2 inhibition reverses the protumor phenotype of macrophages mediated by epigenetic modulation induced by the HDAC2-SP1 axis, indicating a therapeutic option to modify the immunosuppressive tumor microenvironment.

    View details for DOI 10.1158/0008-5472.CAN-22-1270

    View details for PubMedID 37205635

  • Zooming into Cellular and Molecular Heterogeneity of Pulmonary Hypertension. What More Single-Cell Omics Can Offer. American journal of respiratory and critical care medicine Chelladurai, P., Savai, R., Pullamsetti, S. S. 2021; 203 (8): 941-943

    View details for DOI 10.1164/rccm.202010-3889ED

    View details for PubMedID 33171066

    View details for PubMedCentralID PMC8048759

  • CILP1 as a biomarker for right ventricular maladaptation in pulmonary hypertension. The European respiratory journal Keranov, S., Dörr, O., Jafari, L., Troidl, C., Liebetrau, C., Kriechbaum, S., Keller, T., Voss, S., Bauer, T., Lorenz, J., Richter, M. J., Tello, K., Gall, H., Ghofrani, H. A., Mayer, E., Wiedenroth, C. B., Guth, S., Lörchner, H., Pöling, J., Chelladurai, P., Pullamsetti, S. S., Braun, T., Seeger, W., Hamm, C. W., Nef, H. 2021; 57 (4)

    Abstract

    The aim of our study was to analyse the protein expression of cartilage intermediate layer protein (CILP)1 in a mouse model of right ventricular (RV) pressure overload and to evaluate CILP1 as a biomarker of cardiac remodelling and maladaptive RV function in patients with pulmonary hypertension (PH).Pulmonary artery banding was performed in 14 mice; another nine mice underwent sham surgery. CILP1 protein expression was analysed in all hearts using Western blotting and immunostaining. CILP1 serum concentrations were measured in 161 patients (97 with adaptive and maladaptive RV pressure overload caused by PH; 25 with left ventricular (LV) hypertrophy; 20 with dilative cardiomyopathy (DCM); 19 controls without LV or RV abnormalities)In mice, the amount of RV CILP1 was markedly higher after banding than after sham. Control patients had lower CILP1 serum levels than all other groups (p<0.001). CILP1 concentrations were higher in PH patients with maladaptive RV function than those with adaptive RV function (p<0.001), LV pressure overload (p<0.001) and DCM (p=0.003). CILP1 showed good predictive power for maladaptive RV in receiver operating characteristic analysis (area under the curve (AUC) 0.79). There was no significant difference between the AUCs of CILP1 and N-terminal pro-brain natriuretic peptide (NT-proBNP) (AUC 0.82). High CILP1 (cut-off value for maladaptive RV of ≥4373 pg·mL-1) was associated with lower tricuspid annular plane excursion/pulmonary artery systolic pressure ratios (p<0.001) and higher NT-proBNP levels (p<0.001).CILP1 is a novel biomarker of RV and LV pathological remodelling that is associated with RV maladaptation and ventriculoarterial uncoupling in patients with PH.

    View details for DOI 10.1183/13993003.01192-2019

    View details for PubMedID 33184116

  • Targeting histone acetylation in pulmonary hypertension and right ventricular hypertrophy. British journal of pharmacology Chelladurai, P., Boucherat, O., Stenmark, K., Kracht, M., Seeger, W., Bauer, U. M., Bonnet, S., Pullamsetti, S. S. 2021; 178 (1): 54-71

    Abstract

    Epigenetic mechanisms, including DNA methylation and histone post-translational modifications (PTMs), have been known to regulate chromatin structure and lineage-specific gene expression during cardiovascular development and disease. However, alterations in the landscape of histone PTMs and their contribution to the pathogenesis of incurable cardiovascular diseases such as pulmonary hypertension (PH) and associated right heart failure (RHF) remain largely unexplored. This review focusses on the studies in PH and RHF that investigated the gene families that write (histone acetyltransferases), read (bromodomain-containing proteins) or erase (histone deacetylases [HDACs] and sirtuins [SIRT]) acetyl moieties from the ε-amino group of lysine residues of histones and non-histone proteins. Analysis of cells and tissues isolated from the in vivo preclinical models of PH and human pulmonary arterial hypertension not only confirmed significant alterations in the expression levels of multiple HDACs, SIRT1, SIRT3 and BRD4 proteins but also demonstrated their strong association to proliferative, inflammatory and fibrotic phenotypes linked to the pathological vascular remodelling process. Due to the reversible nature of post-translational protein acetylation, the therapeutic efficacy of numerous small-molecule inhibitors (vorinostat, valproic acid, sodium butyrate, mocetinostat, entinostat, tubastatin A, apabetalone, JQ1 and resveratrol) have been evaluated in different preclinical models of cardiovascular disease, which revealed the promising therapeutic benefits of targeting histone acetylation pathways in the attenuation of cardiac hypertrophy, fibrosis, left heart dysfunction, PH and RHF. This review also emphasizes the need for deeper molecular insights into the contribution of epigenetic changes to PH pathogenesis and therapeutic evaluation of isoform-specific modulation in ex vivo and in vivo models of PH and RHF. LINKED ARTICLES: This article is part of a themed issue on Risk factors, comorbidities, and comedications in cardioprotection. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v178.1/issuetoc.

    View details for DOI 10.1111/bph.14932

    View details for PubMedID 31749139

  • Isoform-specific characterization of class I histone deacetylases and their therapeutic modulation in pulmonary hypertension. Scientific reports Chelladurai, P., Dabral, S., Basineni, S. R., Chen, C. N., Schmoranzer, M., Bender, N., Feld, C., Nötzold, R. R., Dobreva, G., Wilhelm, J., Jungblut, B., Zhao, L., Bauer, U. M., Seeger, W., Pullamsetti, S. S. 2020; 10 (1): 12864

    Abstract

    Pharmacological modulation of class I histone deacetylases (HDAC) has been evaluated as a therapeutic strategy for pulmonary hypertension (PH) in experimental models of PH. However, information of their expression, regulation and transcriptional targets in human PH and the therapeutic potential of isoform-selective enzyme modulation are lacking. Comprehensive analysis of expression and regulation of class I HDACs (HDAC1, HDAC2, HDAC3 and HDAC8) was performed in cardiopulmonary tissues and adventitial fibroblasts isolated from pulmonary arteries (PAAF) of idiopathic pulmonary arterial hypertension (IPAH) patients and healthy donors. Cellular functions and transcriptional targets of HDAC enzymes were investigated. Therapeutic effects of pan-HDAC (Vorinostat), class-selective (VPA) and isoform-selective (CAY10398, Romidepsin, PCI34051) HDAC inhibitors were evaluated ex vivo (IPAH-PAAF, IPAH-PASMC) and in vivo (rat chronic hypoxia-induced PH and zebrafish angiogenesis). Our screening identifies dysregulation of class I HDAC isoforms in IPAH. Particularly, HDAC1 and HDAC8 were consistently increased in IPAH-PAs and IPAH-PAAFs, whereas HDAC2 and HDAC8 showed predominant localization with ACTA2-expressing cells in extensively remodeled IPAH-PAs. Hypoxia not only significantly modulated protein levels of deacetylase (HDAC8), but also significantly caused dynamic changes in the global histone lysine acetylation levels (H3K4ac, H3K9/K14ac and H3K27ac). Importantly, isoform-specific RNA-interference revealed that HDAC isoforms regulate distinct subset of transcriptome in IPAH-PAAFs. Reduced transcript levels of KLF2 in IPAH-PAAFs was augmented by HDAC8 siRNA and HDAC inhibitors, which also attenuated IPAH-associated hyperproliferation and apoptosis-resistance ex vivo, and mitigated chronic hypoxia-induced established PH in vivo, at variable degree. Class I HDAC isoforms are significantly dysregulated in human PAH. Isoform-selective HDAC inhibition is a viable approach to circumvent off-target effects.

    View details for DOI 10.1038/s41598-020-69737-x

    View details for PubMedID 32733053

    View details for PubMedCentralID PMC7393135

  • Cancer and pulmonary hypertension: Learning lessons and real-life interplay. Global cardiology science & practice Pullamsetti, S. S., Nayakanti, S., Chelladurai, P., Mamazhakypov, A., Mansouri, S., Savai, R., Seeger, W. 2020; 2020 (1): e202010

    Abstract

    This article reviews the scientific reasons that support the intriguing vision of pulmonary hypertension (PH) as a disease with a cancer-like nature and to understand whether this point of view may have fruitful consequences for the overall management of PH. This review compares cancer and PH in view of Hanahan and Weinberg's principles (i.e., hallmarks of cancer) with an emphasis on hyperproliferative, metabolic, and immune/inflammatory aspects of the disease. In addition, this review provides a perspective on the role of transcription factors and chromatin and epigenetic aberrations, besides genetics, as "common driving mechanisms" of PH hallmarks and the foreseeable use of transcription factor/epigenome targeting as multitarget approach against the hallmarks of PH. Thus, recognition of the widespread applicability and analogy of these concepts will increasingly affect the development of new means of PH treatment.

    View details for DOI 10.21542/gcsp.2020.10

    View details for PubMedID 33150154

    View details for PubMedCentralID PMC7590929

  • Transcription factors, transcriptional coregulators, and epigenetic modulation in the control of pulmonary vascular cell phenotype: therapeutic implications for pulmonary hypertension (2015 Grover Conference series). Pulmonary circulation Pullamsetti, S. S., Perros, F., Chelladurai, P., Yuan, J., Stenmark, K. 2016; 6 (4): 448-464

    Abstract

    Pulmonary hypertension (PH) is a complex and multifactorial disease involving genetic, epigenetic, and environmental factors. Numerous stimuli and pathological conditions facilitate severe vascular remodeling in PH by activation of a complex cascade of signaling pathways involving vascular cell proliferation, differentiation, and inflammation. Multiple signaling cascades modulate the activity of certain sequence-specific DNA-binding transcription factors (TFs) and coregulators that are critical for the transcriptional regulation of gene expression that facilitates PH-associated vascular cell phenotypes, as demonstrated by several studies summarized in this review. Past studies have largely focused on the role of the genetic component in the development of PH, while the presence of epigenetic alterations such as microRNAs, DNA methylation, histone levels, and histone deacetylases in PH is now also receiving increasing attention. Epigenetic regulation of chromatin structure is also recognized to influence gene expression in development or disease states. Therefore, a complete understanding of the mechanisms involved in altered gene expression in diseased cells is vital for the design of novel therapeutic strategies. Recent technological advances in DNA sequencing will provide a comprehensive improvement in our understanding of mechanisms involved in the development of PH. This review summarizes current concepts in TF and epigenetic control of cell phenotype in pulmonary vascular disease and discusses the current issues and possibilities in employing potential epigenetic or TF-based therapies for achieving complete reversal of PH.

    View details for DOI 10.1086/688908

    View details for PubMedID 28090287

    View details for PubMedCentralID PMC5210074

  • Epigenetic mechanisms in pulmonary arterial hypertension: the need for global perspectives. European respiratory review : an official journal of the European Respiratory Society Chelladurai, P., Seeger, W., Pullamsetti, S. S. 2016; 25 (140): 135-40

    Abstract

    Pulmonary arterial hypertension (PAH) is a severe and progressive disease, characterised by high pulmonary artery pressure that usually culminates in right heart failure. Recent findings of alterations in the DNA methylation state of superoxide dismutase 2 and granulysin gene loci; histone H1 levels; aberrant expression levels of histone deacetylases and bromodomain-containing protein 4; and dysregulated microRNA networks together suggest the involvement of epigenetics in PAH pathogenesis. Thus, PAH pathogenesis evidently involves the interplay of a predisposed genetic background, epigenetic state and injurious events. Profiling the genome-wide alterations in the epigenetic mechanisms, such as DNA methylation or histone modification pattern in PAH vascular cells, may explain the great variability in susceptibility and disease severity that is frequently associated with pronounced remodelling and worse clinical outcome. Moreover, the influence of genetic predisposition and the acquisition of epigenetic alterations in response to environmental cues in PAH progression and establishment has largely been unexplored on a genome-wide scale. In order to gain insights into the molecular mechanisms leading to the development of PAH and to design novel therapeutic strategies, high-throughput approaches have to be adopted to facilitate systematic identification of the disease-specific networks using next-generation sequencing technologies, the application of these technologies in PAH has been relatively trivial to date.

    View details for DOI 10.1183/16000617.0036-2016

    View details for PubMedID 27246590

    View details for PubMedCentralID PMC9487251

  • Matrix metalloproteinases and their inhibitors in pulmonary hypertension. The European respiratory journal Chelladurai, P., Seeger, W., Pullamsetti, S. S. 2012; 40 (3): 766-82

    Abstract

    Pulmonary hypertension (PH) is a severe and progressive disease characterised by high pulmonary artery pressure, usually culminating in right heart failure. Current therapeutic approaches in PH largely provide symptomatic relief while the prognosis rate is lower due to the lack of specific molecular targets and the involvement of several factors in the development of PH. Numerous studies have suggested a crucial role of matrix metalloproteinase (MMP) axis during development and disease states, specifically with regard to extracellular matrix remodelling and vascular homeostasis. Increased MMP activity has been demonstrated in experimental animal models of PH, and MMP inhibition has been shown to either attenuate or enhance vascular remodelling. Moreover, several studies emphasise that restoration of deregulated MMPs to physiological MMP/tissue inhibitor of MMPs ratios would potentiate reverse remodelling in PH. This article will highlight the pathophysiological role of MMPs in vascular remodelling and the establishment of PH. In particular, we will focus on the MMP expression and regulation in pulmonary vasculature and pulmonary vascular remodelling. We will also provide an overview of recent clinical and experimental findings and their impact on achieving maximum reversal of PH, as well as current issues and future perspectives.

    View details for DOI 10.1183/09031936.00209911

    View details for PubMedID 22523364