Colwyn Headley

All Publications

• Revolutionizing Postdoctoral Training Using the Social Ecological Model: Insights and Experiences from the Propel Scholars GEN BIOTECHNOLOGY Hayes, C. A., Headley, C. A., Nava, A. R., Vizcarra, E. A., Garcia, K. C., Mullen, M. S., Morales, J., Venida, A. C., Follis, S. 2024

  View details for DOI 10.1089/genbio.2024.0014

  View details for Web of Science ID 001283346900001

• Mitochondrial Transplantation Promotes Protective Effector and Memory CD4+ T Cell Response During Mycobacterium Tuberculosis Infection and Diminishes Exhaustion and Senescence in Elderly CD4+ T cells. Advanced science (Weinheim, Baden-Wurttemberg, Germany) Headley, C. A., Gautam, S., Olmo-Fontanez, A., Garcia-Vilanova, A., Dwivedi, V., Schami, A., Weintraub, S., Tsao, P. S., Torrelles, J. B., Turner, J. 2024: e2401077

  Abstract

  Tuberculosis (TB), caused by Mycobacterium tuberculosis (M.tb), is a major global health concern, particularly affecting those with weakened immune systems, including the elderly. CD4+ T cell response is crucial for immunity against M.tb, but chronic infections and aging can lead to T cell exhaustion and senescence, worsening TB disease. Mitochondrial dysfunction, prevalent in aging and chronic diseases, disrupts cellular metabolism, increases oxidative stress, and impairs T-cell functions. This study investigates the effect of mitochondrial transplantation (mito-transfer) on CD4+ T cell differentiation and function in aged mouse models and human CD4+ T cells from elderly individuals. Mito-transfer in naïve CD4+ T cells is found to promote protective effector and memory T cell generation during M.tb infection in mice. Additionally, it improves elderly human T cell function by increasing mitochondrial mass and altering cytokine production, thereby reducing markers of exhaustion and senescence. These findings suggest mito-transfer as a novel approach to enhance aged CD4+ T cell functionality, potentially benefiting immune responses in the elderly and chronic TB patients. This has broader implications for diseases where mitochondrial dysfunction contributes to T-cell exhaustion and senescence.

  View details for DOI 10.1002/advs.202401077

  View details for PubMedID 39039808

• Unlocking the power of virtual networking for early-career researchers. eLife Hayes, C. A., Moore, J. T., Headley, C. A., Berrios-Negron, A. L., Lambert, W. M. 2024; 13

  Abstract

  Many successful researchers in the biomedical sciences have benefitted from mentors and networks earlier in their career. However, early-career researchers from minoritized and underrepresented groups do not have the same access to potential mentors and networks as many of their peers. In this article we describe how 'cold emails' and social media platforms - notably Twitter/X and LinkedIn - can be used to build virtual networks, and stress the need to invest in maintaining networks once they have been established.

  View details for DOI 10.7554/eLife.96381

  View details for PubMedID 38501601

• Mitochondrial Transplantation promotes protective effector and memory CD4+ T cell response during Mycobacterium tuberculosis infection and diminishes exhaustion and senescence in elderly CD4+ T cells. bioRxiv : the preprint server for biology Headley, C. A., Gautam, S., Olmo-Fontanez, A., Garcia-Vilanova, A., Dwivedi, V., Schami, A., Weintraub, S., Tsao, P. S., Torrelles, J. B., Turner, J. 2024

  Abstract

  Tuberculosis (TB), caused by the bacterium Mycobacterium tuberculosis (M.tb), remains a significant health concern worldwide, especially in populations with weakened or compromised immune systems, such as the elderly. Proper adaptive immune function, particularly a CD4+ T cell response, is central to host immunity against M.tb. Chronic infections, such as M.tb, as well as aging promote T cell exhaustion and senescence, which can impair immune control and promote progression to TB disease. Mitochondrial dysfunction contributes to T cell dysfunction, both in aging and chronic infections and diseases. Mitochondrial perturbations can disrupt cellular metabolism, enhance oxidative stress, and impair T-cell signaling and effector functions. This study examined the impact of mitochondrial transplantation (mito-transfer) on CD4+ T cell differentiation and function using aged mouse models and human CD4+ T cells from elderly individuals. Our study revealed that mito-transfer in naïve CD4+ T cells promoted the generation of protective effector and memory CD4+ T cells during M.tb infection in mice. Further, mito-transfer enhanced the function of elderly human T cells by increasing their mitochondrial mass and modulating cytokine production, which in turn reduced exhaustion and senescence cell markers. Our results suggest that mito-transfer could be a novel strategy to reestablish aged CD4+ T cell function, potentially improving immune responses in the elderly and chronic TB patients, with a broader implication for other diseases where mitochondrial dysfunction is linked to T cell exhaustion and senescence.

  View details for DOI 10.1101/2024.01.24.577036

  View details for PubMedID 38328206

  View details for PubMedCentralID PMC10849707

• Extracellular Delivery of Functional Mitochondria Rescues the Dysfunction of CD4+T Cells in Aging. Advanced science (Weinheim, Baden-Wurttemberg, Germany) Headley, C. A., Gautam, S., Olmo-Fontanez, A., Garcia-Vilanova, A., Dwivedi, V., Akhter, A., Schami, A., Chiem, K., Ault, R., Zhang, H., Cai, H., Whigham, A., Delgado, J., Hicks, A., Tsao, P. S., Gelfond, J., Martinez-Sobrido, L., Wang, Y., Torrelles, J. B., Turner, J. 2023: e2303664

  Abstract

  Mitochondrial dysfunction alters cellular metabolism, increases tissue oxidative stress, and may be principal to the dysregulated signaling and function of CD4+ T lymphocytes in the elderly. In this proof of principle study, it is investigated whether the transfer of functional mitochondria into CD4+ T cells that are isolated from old mice (aged CD4+ T cells), can abrogate aging-associated mitochondrial dysfunction, and improve the aged CD4+ T cell functionality. The results show that the delivery of exogenous mitochondria to aged non-activated CD4+ T cells led to significant mitochondrial proteome alterations highlighted by improved aerobic metabolism and decreased cellular mitoROS. Additionally, mito-transferred aged CD4+ T cells showed improvements in activation-induced TCR-signaling kinetics displaying markers of activation (CD25), increased IL-2 production, enhanced proliferation ex vivo. Importantly, immune deficient mouse models (RAG-KO) showed that adoptive transfer of mito-transferred naive aged CD4+ T cells, protected recipient mice from influenza A and Mycobacterium tuberculosis infections. These findings support mitochondria as targets of therapeutic intervention in aging.

  View details for DOI 10.1002/advs.202303664

  View details for PubMedID 37990641

• Diversity, Equity and Inclusion in the Laboratory: Strategies to Enhance Inclusive Laboratory Culture. Molecular cell Marshall, A. G., Vue, Z., Beasley, H. K., Neikirk, K., Stephens, D., Wanjalla, C. N., Damo, S. M., Trejo, J., Rodriguez-Aliaga, P., Headley, C. A., Shuler, H., Liu, K., Smith, N., Garza-Lopez, E., Barongan, T., Scudese, E., Spencer, E., Heemstra, J., Vazquez, A. D., Murray, S. A., Hinton, A. J. 2023; 83 (21): 3766-3772

  Abstract

  Building a diverse laboratory that is equitable is critical for the retention of talent and the growth of trainees professionally and personally. Here, we outline several strategies including enhancing understanding of cultural competency and humility, establishing laboratory values, and developing equitable laboratory structures to create an inclusive laboratory environment to enable trainees to achieve their highest success.

  View details for DOI 10.1016/j.molcel.2023.09.011

  View details for PubMedID 37922871

• Genome-wide association meta-analysis identifies risk loci for abdominal aortic aneurysm and highlights PCSK9 as a therapeutic target NATURE GENETICS Roychowdhury, T., Klarin, D., Levin, M. G., Spin, J. M., Rhee, Y., Deng, A., Headley, C. A., Tsao, N. L., Gellatly, C., Zuber, V., Shen, F., Hornsby, W. E., Laursen, I., Verma, S. S., Locke, A. E., Einarsson, G., Thorleifsson, G., Graham, S. E., Dikilitas, O., Pattee, J. W., Judy, R. L., Pauls-Verges, F., Nielsen, J. B., Wolford, B. N., Brumpton, B. M., Dilme, J., Peypoch, O., Juscafresa, L., Edwards, T. L., Li, D., Banasik, K., Brunak, S., Jacobsen, R. L., Garcia-Barrio, M. T., Zhang, J., Rasmussen, L. M., Lee, R., Handa, A., Wanhainen, A., Mani, K., Lindholt, J. S., Obel, L. M., Strauss, E., Oszkinis, G., Nelson, C. P., Saxby, K. L., van Herwaarden, J. A., van der Laan, S. W., van Setten, J., Camacho, M., Davis, F. M., Wasikowski, R., Tsoi, L. C., Gudjonsson, J. E., Eliason, J. L., Coleman, D. M., Henke, P. K., Ganesh, S. K., Chen, Y., Guan, W., Pankow, J. S., Pankratz, N., Pedersen, O. B., Erikstrup, C., Tang, W., Hveem, K., Gudbjartsson, D., Gretarsdottir, S., Thorsteinsdottir, U., Holm, H., Stefansson, K., Ferreira, M. A., Baras, A., Kullo, I. J., Ritchie, M. D., Christensen, A. H., Iversen, K. K., Eldrup, N., Sillesen, H., Ostrowski, S. R., Bundgaard, H., Ullum, H., Burgess, S., Gill, D., Gallagher, K., Sabater-Lleal, M., Surakka, I., Jones, G. T., Bown, M. J., Tsao, P. S., Willer, C. J., Damrauer, S. M., Dudbridge, F., Samani, N. J., DiscovEHR, Regeneron Genetics Ctr, UK Aneurysm Growth Study, DBDS Genomic Consortium, VA Million Vet Program 2023

  View details for DOI 10.1038/s41588-023-01510

  View details for Web of Science ID 001085082700001

• Genome-wide association meta-analysis identifies risk loci for abdominal aortic aneurysm and highlights PCSK9 as a therapeutic target. Nature genetics Roychowdhury, T., Klarin, D., Levin, M. G., Spin, J. M., Rhee, Y. H., Deng, A., Headley, C. A., Tsao, N. L., Gellatly, C., Zuber, V., Shen, F., Hornsby, W. E., Laursen, I. H., Verma, S. S., Locke, A. E., Einarsson, G., Thorleifsson, G., Graham, S. E., Dikilitas, O., Pattee, J. W., Judy, R. L., Pauls-Verges, F., Nielsen, J. B., Wolford, B. N., Brumpton, B. M., Dilmé, J., Peypoch, O., Juscafresa, L. C., Edwards, T. L., Li, D., Banasik, K., Brunak, S., Jacobsen, R. L., Garcia-Barrio, M. T., Zhang, J., Rasmussen, L. M., Lee, R., Handa, A., Wanhainen, A., Mani, K., Lindholt, J. S., Obel, L. M., Strauss, E., Oszkinis, G., Nelson, C. P., Saxby, K. L., van Herwaarden, J. A., van der Laan, S. W., van Setten, J., Camacho, M., Davis, F. M., Wasikowski, R., Tsoi, L. C., Gudjonsson, J. E., Eliason, J. L., Coleman, D. M., Henke, P. K., Ganesh, S. K., Chen, Y. E., Guan, W., Pankow, J. S., Pankratz, N., Pedersen, O. B., Erikstrup, C., Tang, W., Hveem, K., Gudbjartsson, D., Gretarsdottir, S., Thorsteinsdottir, U., Holm, H., Stefansson, K., Ferreira, M. A., Baras, A., Kullo, I. J., Ritchie, M. D., Christensen, A. H., Iversen, K. K., Eldrup, N., Sillesen, H., Ostrowski, S. R., Bundgaard, H., Ullum, H., Burgess, S., Gill, D., Gallagher, K., Sabater-Lleal, M., Surakka, I., Jones, G. T., Bown, M. J., Tsao, P. S., Willer, C. J., Damrauer, S. M. 2023

  Abstract

  Abdominal aortic aneurysm (AAA) is a common disease with substantial heritability. In this study, we performed a genome-wide association meta-analysis from 14 discovery cohorts and uncovered 141 independent associations, including 97 previously unreported loci. A polygenic risk score derived from meta-analysis explained AAA risk beyond clinical risk factors. Genes at AAA risk loci indicate involvement of lipid metabolism, vascular development and remodeling, extracellular matrix dysregulation and inflammation as key mechanisms in AAA pathogenesis. These genes also indicate overlap between the development of AAA and other monogenic aortopathies, particularly via transforming growth factor β signaling. Motivated by the strong evidence for the role of lipid metabolism in AAA, we used Mendelian randomization to establish the central role of nonhigh-density lipoprotein cholesterol in AAA and identified the opportunity for repurposing of proprotein convertase, subtilisin/kexin-type 9 (PCSK9) inhibitors. This was supported by a study demonstrating that PCSK9 loss of function prevented the development of AAA in a preclinical mouse model.

  View details for DOI 10.1038/s41588-023-01510-y

  View details for PubMedID 37845353

  View details for PubMedCentralID 5800308

• IL-10 Modulation Increases Pyrazinamide's Antimycobacterial Efficacy against Mycobacterium tuberculosis Infection in Mice. ImmunoHorizons Dwivedi, V., Gautam, S., Beamer, G., Stromberg, P. C., Headley, C. A., Turner, J. 2023; 7 (6): 412-420

  Abstract

  Mechanisms to shorten the duration of tuberculosis (TB) treatment include new drug formulations or schedules and the development of host-directed therapies (HDTs) that better enable the host immune system to eliminate Mycobacterium tuberculosis. Previous studies have shown that pyrazinamide, a first-line antibiotic, can also modulate immune function, making it an attractive target for combinatorial HDT/antibiotic therapy, with the goal to accelerate clearance of M. tuberculosis. In this study, we assessed the value of anti-IL-10R1 as an HDT along with pyrazinamide and show that short-term anti-IL-10R1 blockade during pyrazinamide treatment enhanced the antimycobacterial efficacy of pyrazinamide, resulting in faster clearance of M. tuberculosis in mice. Furthermore, 45 d of pyrazinamide treatment in a functionally IL-10-deficient environment resulted in sterilizing clearance of M. tuberculosis. Our data suggest that short-term IL-10 blockade with standard TB drugs has the potential to improve clinical outcome by reducing the treatment duration.

  View details for DOI 10.4049/immunohorizons.2200077

  View details for PubMedID 37279084

• Building the case for mitochondrial transplantation as an anti-aging cardiovascular therapy. Frontiers in cardiovascular medicine Headley, C. A., Tsao, P. S. 2023; 10: 1141124

  Abstract

  Mitochondrial dysfunction is a common denominator in both biological aging and cardiovascular disease (CVD) pathology. Understanding the protagonist role of mitochondria in the respective and independent progressions of CVD and biological aging will unravel the synergistic relationship between biological aging and CVD. Moreover, the successful development and implementation of therapies that can simultaneously benefit mitochondria of multiple cell types, will be transformational in curtailing pathologies and mortality in the elderly, including CVD. Several works have compared the status of mitochondria in vascular endothelial cells (ECs) and vascular smooth muscle cells (VSMCs) in CVD dependent context. However, fewer studies have cataloged the aging-associated changes in vascular mitochondria, independent of CVD. This mini review will focus on the present evidence related to mitochondrial dysfunction in vascular aging independent of CVD. Additionally, we discuss the feasibility of restoring mitochondrial function in the aged cardiovascular system through mitochondrial transfer.

  View details for DOI 10.3389/fcvm.2023.1141124

  View details for PubMedID 37229220

  View details for PubMedCentralID PMC10203246

• A Practical Guide to Graduate School Interviewing for Historically Excluded Individuals. American journal of physiology. Heart and circulatory physiology Ransey, E., Brookens, S., Beasley, H. K., Marshall, A., Marlin, B. J., Rodriguez-Aliaga, P., Headley, C. A., Wanjalla, C., Vazquez, A. D., Murray, S., Damo, S., Taabazuing, C. Y., Hinton, A. J. 2023

  View details for DOI 10.1152/ajpheart.00123.2023

  View details for PubMedID 37027327

• IL-10 Receptor Blockade Delivered Simultaneously with Bacillus Calmette-Guerin Vaccination Sustains Long-Term Protection against Mycobacterium tuberculosis Infection in Mice. Journal of immunology (Baltimore, Md. : 1950) Dwivedi, V., Gautam, S., Headley, C. A., Piergallini, T., Torrelles, J. B., Turner, J. 2022

  Abstract

  Mycobacterium bovis bacillus Calmette-Guerin (BCG) immunization still remains the best vaccination strategy available to control the development of active tuberculosis. Protection afforded by BCG vaccination gradually wanes over time and although booster strategies have promise, they remain under development. An alternative approach is to improve BCG efficacy through host-directed therapy. Building upon prior knowledge that blockade of IL-10R1 during early Mycobacterium tuberculosis infection improves and extends control of M. tuberculosis infection in mice, we employed a combined anti-IL-10R1/BCG vaccine strategy. An s.c. single vaccination of BCG/anti-IL10-R1 increased the numbers of CD4+ and CD8+ central memory T cells and reduced Th1 and Th17 cytokine levels in the lung for up to 7 wk postvaccination. Subsequent M. tuberculosis challenge in mice showed both an early (4 wk) and sustained long-term (47 wk) control of infection, which was associated with increased survival. In contrast, protection of BCG/saline-vaccinated mice waned 8 wk after M. tuberculosis infection. Our findings demonstrate that a single and simultaneous vaccination with BCG/anti-IL10-R1 sustains long-term protection, identifying a promising approach to enhance and extend the current BCG-mediated protection against TB.

  View details for DOI 10.4049/jimmunol.2100900

  View details for PubMedID 35181640

• Local immune responses to tuberculin skin challenge in Mycobacterium bovis BCG-vaccinated baboons: a pilot study of younger and older animals IMMUNITY & AGEING Scordo, J. M., Piergallini, T. J., Reuter, N., Headley, C. A., Hodara, V. L., Gonzalez, O., Giavedoni, L. D., Papin, J. F., Turner, J. 2021; 18 (1): 16

  Abstract

  Individuals over the age of 65 are highly susceptible to infectious diseases, which account for one-third of deaths in this age group. Vaccines are a primary tool to combat infection, yet they are less effective in the elderly population. While many groups have aimed to address this problem by studying vaccine-induced peripheral blood responses in the elderly, work from our lab and others demonstrate that immune responses to vaccination and infectious challenge may differ between tissue sites and the periphery. In this pilot study, we established an in vivo delayed-type hypersensitivity model of Mycobacterium bovis BCG vaccination and tuberculin skin test in two adult and two aged baboons. Vaccination generates BCG-specific immune cells that are recruited to the skin upon tuberculin challenge. We tested short term recall responses (8 weeks post-vaccination) and long term recall responses (25 weeks post-vaccination) by performing skin punch biopsies around the site of tuberculin injection. In short term recall responses, we found increased oxidation and decreased production of immune proteins in aged baboon skin at the site of TST challenge, in comparison to adult skin. Differences between adult and aged animals normalized in the long term response to tuberculin. In vitro, aged peripheral blood mononuclear cells had increased migration and functional responses to antigen-specific stimulation, suggesting that age-related changes in the tissue in vivo impairs aged immune recall responses to antigenic challenge. These findings highlight the impact of age-associated changes in the local tissue environment in memory recall responses, which may be more broadly applied to the study of other tissues. Moreover, these findings should be considered in future studies aimed at understanding and improving aging immune responses to vaccination and tissue challenge.

  View details for DOI 10.1186/s12979-021-00229-w

  View details for Web of Science ID 000637773900001

  View details for PubMedID 33827617

  View details for PubMedCentralID PMC8024439

• Lethality of SARS-CoV-2 infection in K18 human angiotensin-converting enzyme 2 transgenic mice NATURE COMMUNICATIONS Oladunni, F. S., Park, J., Pino, P. A., Gonzalez, O., Akhter, A., Allue-Guardia, A., Olmo-Fontanez, A., Gautam, S., Garcia-Vilanova, A., Ye, C., Chiem, K., Headley, C., Dwivedi, V., Parodi, L. M., Alfson, K. J., Staples, H. M., Schami, A., Garcia, J., Whigham, A., Platt, R., Gazi, M., Martinez, J., Chuba, C., Earley, S., Rodriguez, O. H., Mdaki, S., Kavelish, K. N., Escalona, R., Hallam, C. A., Christie, C., Patterson, J. L., Anderson, T. C., Carrion, R., Dick, E. J., Hall-Ursone, S., Schlesinger, L. S., Alvarez, X., Kaushal, D., Giavedoni, L. D., Turner, J., Martinez-Sobrido, L., Torrelles, J. B. 2020; 11 (1): 6122

  Abstract

  Vaccine and antiviral development against SARS-CoV-2 infection or COVID-19 disease would benefit from validated small animal models. Here, we show that transgenic mice expressing human angiotensin-converting enzyme 2 (hACE2) by the human cytokeratin 18 promoter (K18 hACE2) represent a susceptible rodent model. K18 hACE2 transgenic mice succumbed to SARS-CoV-2 infection by day 6, with virus detected in lung airway epithelium and brain. K18 ACE2 transgenic mice produced a modest TH1/2/17 cytokine storm in the lung and spleen that peaked by day 2, and an extended chemokine storm that was detected in both lungs and brain. This chemokine storm was also detected in the brain at day 6. K18 hACE2 transgenic mice are, therefore, highly susceptible to SARS-CoV-2 infection and represent a suitable animal model for the study of viral pathogenesis, and for identification and characterization of vaccines (prophylactic) and antivirals (therapeutics) for SARS-CoV-2 infection and associated severe COVID-19 disease.

  View details for DOI 10.1038/s41467-020-19891-7

  View details for Web of Science ID 000617695100005

  View details for PubMedID 33257679

  View details for PubMedCentralID PMC7705712

• Blood RNA signatures predict recent tuberculosis exposure in mice, macaques and humans SCIENTIFIC REPORTS Ault, R. C., Headley, C. A., Hare, A. E., Carruthers, B. J., Mejias, A., Turner, J. 2020; 10 (1): 16873

  Abstract

  Tuberculosis (TB) is the leading cause of death due to a single infectious disease. Knowing when a person was infected with Mycobacterium tuberculosis (M.tb) is critical as recent infection is the strongest clinical risk factor for progression to TB disease in immunocompetent individuals. However, time since M.tb infection is challenging to determine in routine clinical practice. To define a biomarker for recent TB exposure, we determined whether gene expression patterns in blood RNA correlated with time since M.tb infection or exposure. First, we found RNA signatures that accurately discriminated early and late time periods after experimental infection in mice and cynomolgus macaques. Next, we found a 6-gene blood RNA signature that identified recently exposed individuals in two independent human cohorts, including adult household contacts of TB cases and adolescents who recently acquired M.tb infection. Our work supports the need for future longitudinal studies of recent TB contacts to determine whether biomarkers of recent infection can provide prognostic information of TB disease risk in individuals and help map recent transmission in communities.

  View details for DOI 10.1038/s41598-020-73942-z

  View details for Web of Science ID 000615371900006

  View details for PubMedID 33037303

  View details for PubMedCentralID PMC7547102

• The role of old age on Mycobacterium bovis BCG vaccine-induced tissue immunity Scordo, J. M., Piergallini, T. J., Headley, C. A., Hodara, V., Reuter, N., Papin, J. F., Turner, J. AMER ASSOC IMMUNOLOGISTS. 2020

  View details for Web of Science ID 000589972402629

• Membrane-specific spin trap, 5-dodecylcarbamoyl-5-N-dodecylacetamide-1-pyroline-N-oxide (diC(12)PO): theoretical, bioorthogonal fluorescence imaging and EPR studies ORGANIC & BIOMOLECULAR CHEMISTRY Headley, C. A., Hoffman, C. N., Freisen, J. M., Han, Y., Macklin, J. M., Zweier, J. L., Rockenbauer, A., Kuret, J., Villamena, F. A. 2019; 17 (33): 7694-7705

  Abstract

  Membranous organelles are major endogenous sources of reactive oxygen and nitrogen species. When present at high levels, these species can cause macromolecular damage and disease. To better detect and scavenge free radical forms of the reactive species at their sources, we investigated whether nitrone spin traps could be selectively targeted to intracellular membranes using a bioorthogonal imaging approach. Electron paramagnetic resonance imaging demonstrated that the novel cyclic nitrone 5-dodecylcarbamoyl-5-N-dodecylacetamide-1-pyroline-N-oxide (diC12PO) could be used to target the nitrone moiety to liposomes composed of phosphatidyl choline. To test localization with authentic membranes in living cells, fluorophores were introduced via strain-promoted alkyne-nitrone cycloaddition (SPANC). Two fluorophore-conjugated alkynes were investigated: hexynamide-fluoresceine (HYA-FL) and dibenzylcyclooctyne-PEG4-5/6-sulforhodamine B (DBCO-Rhod). Computational and mass spectrometry experiments confirmed the cycloadduct formation of DBCO-Rhod (but not HYA-FL) with diC12PO in cell-free solution. Confocal microscopy of bovine aortic endothelial cells treated sequentially with diC12PO and DBCO-Rhod demonstrated clear localization of fluorescence with intracellular membranes. These results indicate that targeting of nitrone spin traps to cellular membranes is feasible, and that a bioorthogonal approach can aid the interrogation of their intracellular compartmentalization properties.

  View details for DOI 10.1039/c9ob01334b

  View details for Web of Science ID 000482070400011

  View details for PubMedID 31328213

  View details for PubMedCentralID PMC6703941

• Aging heart and infection AGING-US Headley, C., Turner, J., Rajaram, M. S. 2019; 11 (14): 4781-4782

  View details for DOI 10.18632/aging.102128

  View details for Web of Science ID 000479140500005

  View details for PubMedID 31346150

  View details for PubMedCentralID PMC6682520

• Nontuberculous mycobacterium M. avium infection predisposes aged mice to cardiac abnormalities and inflammation AGING CELL Headley, C. A., Gerberick, A., Mehta, S., Wu, Q., Yu, L., Fadda, P., Khan, M., Ganesan, L., Turner, J., Rajaram, M. S. 2019; 18 (3): e12926

  Abstract

  Biological aging dynamically alters normal immune and cardiac function, favoring the production of pro-inflammatory cytokines (IL-1β, IL-6, and TNF-α) and increased instances of cardiac distress. Cardiac failure is the primary reason for hospitalization of the elderly (65+ years). The elderly are also increasingly susceptible to developing chronic bacterial infections due to aging associated immune abnormalities. Since bacterial infections compound the rates of cardiac failure in the elderly, and this phenomenon is not entirely understood, the interplay between the immune system and cardiovascular function in the elderly is of great interest. Using Mycobacterium avium, an opportunistic pathogen, we investigated the effect of mycobacteria on cardiac function in aged mice. Young (2-3 months) and old (18-20 months) C57BL/6 mice were intranasally infected with M. avium strain 104, and we compared the bacterial burden, immune status, cardiac electrical activity, pathology, and function of infected mice against uninfected age-matched controls. Herein, we show that biological aging may predispose old mice infected with M. avium to mycobacterial dissemination into the heart tissue and this leads to cardiac dysfunction. M. avium infected old mice had significant dysrhythmia, cardiac hypertrophy, increased recruitment of CD45+ leukocytes, cardiac fibrosis, and increased expression of inflammatory genes in isolated heart tissue. This is the first study to report the effect of mycobacteria on cardiac function in an aged model. Our findings are critical to understanding how nontuberculous mycobacterium (NTM) and other mycobacterial infections contribute to cardiac dysfunction in the elderly population.

  View details for DOI 10.1111/acel.12926

  View details for Web of Science ID 000467861100032

  View details for PubMedID 30834643

• Similarities and differences between porcine mandibular and limb bone marrow mesenchymal stem cells ARCHIVES OF ORAL BIOLOGY Lloyd, B., Tee, B., Headley, C., Emam, H., Mallery, S., Sun, Z. 2017; 77: 1-11

  Abstract

  Research has shown promise of using bone marrow mesenchymal stem cells (BMSCs) for craniofacial bone regeneration; yet little is known about the differences of BMSCs from limb and craniofacial bones. This study compared pig mandibular and tibia BMSCs for their in vitro proliferation, osteogenic differentiation properties and gene expression.Bone marrow was aspirated from the tibia and mandible of 3-4 month-old pigs (n=4), followed by BMSC isolation, culture-expansion and characterization by flow cytometry. Proliferation rates were assessed using population doubling times. Osteogenic differentiation was evaluated by alkaline phosphatase activity. Affymetrix porcine microarray was used to compare gene expressions of tibial and mandibular BMSCs, followed by real-time RT-PCR evaluation of certain genes.Our results showed that BMSCs from both locations expressed MSC markers but not hematopoietic markers. The proliferation and osteogenic differentiation potential of mandibular BMSCs were significantly stronger than those of tibial BMSCs. Microarray analysis identified 404 highly abundant genes, out of which 334 genes were matched between the two locations and annotated into the same functional groups including osteogenesis and angiogenesis, while 70 genes were mismatched and annotated into different functional groups. In addition, 48 genes were differentially expressed by at least 1.5-fold difference between the two locations, including higher expression of cranial neural crest-related gene BMP-4 in mandibular BMSCs, which was confirmed by real-time RT-PCR.Altogether, these data indicate that despite strong similarities in gene expression between mandibular and tibial BMSCs, mandibular BMSCs express some genes differently than tibial BMSCs and have a phenotypic profile that may make them advantageous for craniofacial bone regeneration.

  View details for DOI 10.1016/j.archoralbio.2017.01.012

  View details for Web of Science ID 000399868100001

  View details for PubMedID 28135571

  View details for PubMedCentralID PMC5366281

• Nitrones reverse hyperglycemia-induced endothelial dysfunction in bovine aortic endothelial cells BIOCHEMICAL PHARMACOLOGY Headley, C. A., DiSilvestro, D., Bryant, K. E., Hemann, C., Chen, C., Das, A., Ziouzenkova, O., Durand, G., Villamena, F. A. 2016; 104: 108-117

  Abstract

  Hyperglycemia has been implicated in the development of endothelial dysfunction through heightened ROS production. Since nitrones reverse endothelial nitric oxide synthase (eNOS) dysfunction, increase antioxidant enzyme activity, and suppress pro-apoptotic signaling pathway and mitochondrial dysfunction from ROS-induced toxicity, the objective of this study was to determine whether nitrone spin traps DMPO, PBN and PBN-LA were effective at duplicating these effects and improving glucose uptake in an in vitro model of hyperglycemia-induced dysfunction using bovine aortic endothelial cells (BAEC). BAEC were cultured in DMEM medium with low (5.5mM glucose, LG) or high glucose (50mM, HG) for 14 days to model in vivo hyperglycemia as experienced in humans with metabolic disease. Improvements in cell viability, intracellular oxidative stress, NO and tetrahydrobiopterin (BH4)​ levels, mitochondrial membrane potential, glucose transport, and activity of antioxidant enzymes were measured from single treatment of BAEC with nitrones for 24h after hyperglycemia. Chronic hyperglycemia significantly increased intracellular ROS by 50%, decreased cell viability by 25%, reduced NO bioavailability by 50%, and decreased (BH4) levels by 15% thereby decreasing NO production. Intracellular glucose transport and superoxide dismutase (SOD) activity were also decreased by 50% and 25% respectively. Nitrone (PBN and DMPO, 50 μM) treatment of BAEC grown in hyperglycemic conditions resulted in the normalization of outcome measures except for SOD and catalase activities. Our findings demonstrate that the nitrones reverse the deleterious effects of hyperglycemia in BAEC. We believe that in vivo testing of these nitrone compounds in models of cardiometabolic disease is warranted.

  View details for DOI 10.1016/j.bcp.2016.01.005

  View details for Web of Science ID 000371952600011

  View details for PubMedID 26774452

  View details for PubMedCentralID PMC5248535

• Selected hydroxycoumarins as antioxidants in cells: physicochemical and reactive oxygen species scavenging studies JOURNAL OF PHYSICAL ORGANIC CHEMISTRY Perez-Cruz, F., Villamena, F. A., Zapata-Torres, G., Das, A., Headley, C. A., Quezada, E., Lopez-Alarcon, C., Olea-Azar, C. 2013; 26 (10): 773-783

  View details for DOI 10.1002/poc.3155

  View details for Web of Science ID 000325936700004