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Rogers CD, Kirabo A, McReynolds M, Sweetwyne MT, Wanjalla C, Benjamin J, Williams EM, Gaddy JA, Williams CR, Damo SM, Murray SA, Hinton A. The graduate school guide: How to prepare for the qualifying exam and assemble a thesis/graduate committee. J Cell Physiol 2024. [PMID: 38595027 DOI: 10.1002/jcp.31258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2023] [Revised: 03/02/2024] [Accepted: 03/05/2024] [Indexed: 04/11/2024]
Abstract
Qualifying exams and thesis committees are crucial components of a PhD candidate's journey. However, many candidates have trouble navigating these milestones and knowing what to expect. This article provides advice on meeting the requirements of the qualifying exam, understanding its format and components, choosing effective preparation strategies, retaking the qualifying exam, if necessary, and selecting a thesis committee, all while maintaining one's mental health. This comprehensive guide addresses components of the graduate school process that are often neglected.
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Affiliation(s)
- Crystal D Rogers
- Department of Anatomy, Physiology, and Cell Biology, School of Veterinary Medicine, University of California, Davis, USA
| | - Annet Kirabo
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Melanie McReynolds
- Department of Biochemistry and Molecular Biology, The Huck Institute of the Life Sciences, State College, Pennsylvania State University, University Park, Pennsylvania, USA
| | - Mariya T Sweetwyne
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, Washington, USA
| | - Celestine Wanjalla
- Department of Medicine, Division of Infectious Diseases, Vanderbilt University, Nashville, Tennessee, USA
| | - Jazmine Benjamin
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Edith M Williams
- Department of Public Health Sciences (SMD), University of Rochester, New York, Rochester, USA
| | - Jennifer A Gaddy
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Department of Medicine Health and Society, Vanderbilt University, Nashville, Tennessee, USA
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Department of Veterans Affairs, Tennessee Valley Healthcare Systems, Nashville, Tennessee, USA
| | - Clintoria R Williams
- Department of Neuroscience, Cell Biology and Physiology, Wright State University, Dayton, Ohio, USA
| | - Steven M Damo
- Department of Life and Physical Sciences, Fisk University, Nashville, Tennessee, USA
- Center for Structural Biology, Vanderbilt University, Nashville, Tennessee, USA
| | - Sandra A Murray
- Department of Cell Biology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Antentor Hinton
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, USA
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Beasley HK, Actkins KV, Marshall AG, Garza-Lopez E, Wanjalla C, Scudese E, Kirabo A, Liu K, Hinton A. A quick guide to networking for scientists. Trends Pharmacol Sci 2024; 45:1-4. [PMID: 37968220 DOI: 10.1016/j.tips.2023.10.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Revised: 10/19/2023] [Accepted: 10/19/2023] [Indexed: 11/17/2023]
Abstract
Networking is an important skill for finding social relationships relevant to one's career. However, networking can be difficult to navigate as different social situations and career levels require unique skill sets. Here, we provide tips for effective networking at conferences, dinners, and other events.
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Affiliation(s)
- Heather K Beasley
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232, USA
| | - Ky'Era V Actkins
- Epidemiology Branch, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA; Division of Genetic Medicine, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232, USA; Vanderbilt Genetics Institute, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Andrea G Marshall
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232, USA
| | - Edgar Garza-Lopez
- Department of Internal Medicine, University of Iowa, Iowa City, IA 52242, USA
| | - Celestine Wanjalla
- Department of Medicine, Division of Infectious Diseases, Vanderbilt University, Nashville, TN 37232, USA
| | - Estevão Scudese
- Laboratory of Biosciences of Human Motricity (LABIMH) of the Federal University of State of Rio de Janeiro (UNIRIO), Rio de Janeiro, Brazil; Sport Sciences and Exercise Laboratory (LaCEE), Catholic University of Petrópolis (UCP), Petrópolis, Brazil
| | - Annet Kirabo
- Department of Medicine, Division of Clinical Pharmacology, Vanderbilt University, Nashville, TN 37232, USA
| | - Kaihua Liu
- Department of Anatomy of Cell Biology, University of Iowa, Iowa City, IA 52242, USA
| | - Antentor Hinton
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232, USA.
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Scudese E, Vue Z, Katti P, Marshall A, Vang L, Garza López E, Neikirk K, Stephens D, Hall DD, Rostami R, Shao JQ, Mungai M, AshShareef ST, Hicsasmaz I, Manus S, Wanjalla C, Whiteside A, Williams C, Damo SM, Gaddy JA, Kirabo A, Glancy B, Dantas EHM, Kinder A, Scartoni F, Baffi M, McReynolds MR, Phillips MA, Cooper A, Murray SA, Exil V, Mobley BC, Hinton A. 3D Mitochondrial Structure in Aging Human Skeletal Muscle: Insights into MFN-2 Mediated Changes. bioRxiv 2023:2023.11.13.566502. [PMID: 38168206 PMCID: PMC10760012 DOI: 10.1101/2023.11.13.566502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
Sarcopenia is an age-related loss of skeletal muscle, characterized by loss of mass, strength, endurance, and oxidative capacity during aging. Notably, bioenergetics and protein turnover studies have shown that mitochondria mediate this decline in function. Although mitochondrial aging is associated with decreased mitochondrial capacity, the three-dimensional (3D) mitochondrial structure associated with morphological changes in skeletal muscle during aging still requires further elucidation. Although exercise has been the only therapy to mitigate sarcopenia, the mechanisms that govern these changes remain unclear. We hypothesized that aging causes structural remodeling of mitochondrial 3D architecture representative of dysfunction, and this effect is mitigated by exercise. We used serial block-face scanning electron microscopy to image human skeletal tissue samples, followed by manual contour tracing using Amira software for 3D reconstruction and subsequent analysis of mitochondria. We then applied a rigorous in vitro and in vivo exercise regimen during aging. We found that mitochondria became less complex with age. Specifically, mitochondria lost surface area, complexity, and perimeter, indicating age-related declines in ATP synthesis and interaction capacity. Concomitantly, muscle area, exercise capacity, and mitochondrial dynamic proteins showed age-related losses. Exercise stimulation restored mitofusin 2 (MFN2), which we show is required for mitochondrial structure. Furthermore, we show that this pathway is evolutionarily conserved with Marf, the MFN2 ortholog in Drosophila, as Marf knockdown alters mitochondrial morphology and leads to the downregulation of genes regulating mitochondrial processes. Our results define age-related structural changes in mitochondria and further suggest that exercise may mitigate age-related structural decline through modulation of mitofusins.
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Affiliation(s)
- Estevão Scudese
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
- Laboratory of Biosciences of Human Motricity (LABIMH) of the Federal University of State of Rio de Janeiro (UNIRIO), Rio de Janeiro, Brazil
- Sport Sciences and Exercise Laboratory (LaCEE), Catholic University of Petrópolis (UCP), Brazil
| | - Zer Vue
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
| | - Prassana Katti
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Andrea Marshall
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
| | - Larry Vang
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
| | - Edgar Garza López
- Department of Internal Medicine, University of Iowa, Iowa City, IA, 52242, USA
| | - Kit Neikirk
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
| | - Dominique Stephens
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
| | - Duane D. Hall
- Department of Internal Medicine, University of Iowa, Iowa City, IA, 52242, USA
| | - Rahmati Rostami
- Department of Genetic Medicine, Joan & Sanford I. Weill Medical College of Cornell University, New York, NY, 10065, USA
| | - Jian-qiang Shao
- Central Microscopy Research Facility, Iowa City, IA 52242, USA
| | - Margaret Mungai
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
| | - Salma T. AshShareef
- Department of Internal Medicine, University of Iowa, Iowa City, IA, 52242, USA
| | - Innes Hicsasmaz
- Department of Internal Medicine, University of Iowa, Iowa City, IA, 52242, USA
| | - Sasha Manus
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
| | - Celestine Wanjalla
- Division of Infection Diseases, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, 37232, USA
| | - Aaron Whiteside
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
- Department of Neuroscience, Cell Biology and Physiology, Wright State University, Dayton, OH, 45435, USA
| | - Clintoria Williams
- Department of Neuroscience, Cell Biology and Physiology, Wright State University, Dayton, OH, 45435, USA
| | - Steven M. Damo
- Department of Life and Physical Sciences, Fisk University, Nashville, TN, 37208, USA
| | - Jennifer A. Gaddy
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, 37232, USA
- Tennessee Valley Healthcare Systems, U.S. Department of Veterans Affairs, Nashville, TN, 37212, USA
| | - Annet Kirabo
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Brian Glancy
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, 20892, USA
- NIAMS, NIH, Bethesda, MD, 20892, USA
| | - Estélio Henrique Martin Dantas
- Laboratory of Biosciences of Human Motricity (LABIMH) of the Federal University of State of Rio de Janeiro (UNIRIO), Rio de Janeiro, Brazil
- Doctor’s Degree Program in Nursing and Biosciences - PpgEnfBio, Federal University of the State of Rio de Janeiro - UNIRIO, Rio de Janeiro, RJ, Brazil
- Laboratory of Human Motricity Biosciences - LABIMH, Federal University of the State of Rio de Janeiro - UNIRIO, RJ, Brazil
- Brazilian Paralympic Academy – APB
- Doctor’s Degree Program in Health and Environment - PSA, Tiradentes University - UNIT, Aracaju, SE, Brazil
| | - André Kinder
- Artur Sá Earp Neto University Center - UNIFASE-FMP, Petrópolis Medical School, Brazil
| | - Fabiana Scartoni
- Laboratory of Biosciences of Human Motricity (LABIMH) of the Federal University of State of Rio de Janeiro (UNIRIO), Rio de Janeiro, Brazil
| | - Matheus Baffi
- Sport Sciences and Exercise Laboratory (LaCEE), Catholic University of Petrópolis (UCP), Brazil
| | - Melanie R. McReynolds
- Department of Biochemistry and Molecular Biology, The Huck Institute of the Life Sciences, Pennsylvania State University, State College, PA, 16801, USA
| | - Mark A. Phillips
- Department of Integrative Biology, Oregon State University, Corvallis, OR, 97331, USA
| | - Anthonya Cooper
- Department of Cell Biology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, 15260, USA
| | - Sandra A. Murray
- Department of Cell Biology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, 15260, USA
| | - Vernat Exil
- Department of Pediatrics, Div. of Cardiology, St. Louis University School of Medicine, St. Louis, MO, 63104, USA
| | - Bret C. Mobley
- Department of Pathology, Vanderbilt University Medical Center, Nashville, TN, 37232, USA
| | - Antentor Hinton
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
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Vue Z, Ajayi PT, Neikirk K, Murphy AC, Prasad P, Jenkins BC, Vang L, Garza-Lopez E, Mungai M, Marshall AG, Beasley HK, Killion M, Parker R, Anukodem J, Lavine K, Ajijola O, Mobley BC, Dai DF, Exil V, Kirabo A, Su YR, Tomasek K, Zhang X, Wanjalla C, Hubert DL, Phillips MA, Shao JQ, McReynolds MR, Glancy B, Hinton A. Human Heart Failure Alters Mitochondria and Fiber 3D Structure Triggering Metabolic Shifts. bioRxiv 2023:2023.11.28.569095. [PMID: 38076993 PMCID: PMC10705476 DOI: 10.1101/2023.11.28.569095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2023]
Abstract
This study, utilizing SBF-SEM, reveals structural alterations in mitochondria and myofibrils in human heart failure (HF). Mitochondria in HF show changes in structure, while myofibrils exhibit increased cross-sectional area and branching. Metabolomic and lipidomic analyses indicate concomitant dysregulation in key pathways. The findings underscore the need for personalized treatments considering individualized structural changes in HF.
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Affiliation(s)
- Zer Vue
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN
| | - Peter T. Ajayi
- Muscle Energetics Laboratory, NHLBI, NIH, Bethesda, MD, 20892, USA
| | - Kit Neikirk
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN
| | - Alexandria C. Murphy
- Department of Biochemistry and Molecular Biology, The Huck Institute of the Life Sciences, Pennsylvania State University, State College, PA 16801
| | - Praveena Prasad
- Department of Biochemistry and Molecular Biology, The Huck Institute of the Life Sciences, Pennsylvania State University, State College, PA 16801
| | - Brenita C. Jenkins
- Department of Biochemistry and Molecular Biology, The Huck Institute of the Life Sciences, Pennsylvania State University, State College, PA 16801
| | - Larry Vang
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN
| | - Edgar Garza-Lopez
- Department of Internal Medicine, University of Iowa, Iowa City, IA, 52242, USA
| | - Margaret Mungai
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN
| | - Andrea G. Marshall
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN
| | - Heather K. Beasley
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN
| | - Mason Killion
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN
| | - Remi Parker
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN
| | - Josephs Anukodem
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN
| | - Kory Lavine
- Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA
| | - Olujimi Ajijola
- UCLA Cardiac Arrhythmia Center, University of California, Los Angeles, CA, USA
| | - Bret C. Mobley
- Department of Pathology, Vanderbilt University Medical Center, Nashville, TN, 37232 USA
| | - Dao-Fu Dai
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Vernat Exil
- Department of Pediatrics, Div. of Cardiology, St. Louis University School of Medicine, St. Louis, MO, 63104, USA
| | - Annet Kirabo
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Yan Ru Su
- Department of Medicine, Division of Infectious Diseases, Vanderbilt University, Nashville, TN, 37232, USA
| | - Kelsey Tomasek
- Department of Medicine, Division of Infectious Diseases, Vanderbilt University, Nashville, TN, 37232, USA
| | - Xiuqi Zhang
- Department of Medicine, Division of Infectious Diseases, Vanderbilt University, Nashville, TN, 37232, USA
| | - Celestine Wanjalla
- Department of Medicine, Division of Infectious Diseases, Vanderbilt University, Nashville, TN, 37232, USA
| | - David L. Hubert
- Department of Integrative Biology, Oregon State University, Corvallis, OR, 97331, USA
| | - Mark A. Phillips
- Department of Integrative Biology, Oregon State University, Corvallis, OR, 97331, USA
| | - Jian-qiang Shao
- Central Microscopy Research Facility, Iowa City, IA 52242, USA
| | - Melanie R. McReynolds
- Department of Biochemistry and Molecular Biology, The Huck Institute of the Life Sciences, Pennsylvania State University, State College, PA 16801
| | - Brian Glancy
- Muscle Energetics Laboratory, NHLBI, NIH, Bethesda, MD, 20892, USA
- NIAMS, NIH, Bethesda, MD, 20892, USA
| | - Antentor Hinton
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN
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5
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Vue Z, Neikirk K, Vang L, Garza-Lopez E, Christensen TA, Shao J, Lam J, Beasley HK, Marshall AG, Crabtree A, Anudokem J, Rodriguez B, Kirk B, Bacevac S, Barongan T, Shao B, Stephens DC, Kabugi K, Koh HJ, Koh A, Evans CS, Taylor B, Reddy AK, Miller-Fleming T, Actkins KV, Zaganjor E, Daneshgar N, Murray SA, Mobley BC, Damo SM, Gaddy JA, Riggs B, Wanjalla C, Kirabo A, McReynolds M, Gomez JA, Phillips MA, Exil V, Dai DF, Hinton A. Three-dimensional mitochondria reconstructions of murine cardiac muscle changes in size across aging. Am J Physiol Heart Circ Physiol 2023; 325:H965-H982. [PMID: 37624101 PMCID: PMC10977873 DOI: 10.1152/ajpheart.00202.2023] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Revised: 07/26/2023] [Accepted: 08/12/2023] [Indexed: 08/26/2023]
Abstract
With sparse treatment options, cardiac disease remains a significant cause of death among humans. As a person ages, mitochondria breakdown and the heart becomes less efficient. Heart failure is linked to many mitochondria-associated processes, including endoplasmic reticulum stress, mitochondrial bioenergetics, insulin signaling, autophagy, and oxidative stress. The roles of key mitochondrial complexes that dictate the ultrastructure, such as the mitochondrial contact site and cristae organizing system (MICOS), in aging cardiac muscle are poorly understood. To better understand the cause of age-related alteration in mitochondrial structure in cardiac muscle, we used transmission electron microscopy (TEM) and serial block facing-scanning electron microscopy (SBF-SEM) to quantitatively analyze the three-dimensional (3-D) networks in cardiac muscle samples of male mice at aging intervals of 3 mo, 1 yr, and 2 yr. Here, we present the loss of cristae morphology, the inner folds of the mitochondria, across age. In conjunction with this, the three-dimensional (3-D) volume of mitochondria decreased. These findings mimicked observed phenotypes in murine cardiac fibroblasts with CRISPR/Cas9 knockout of Mitofilin, Chchd3, Chchd6 (some members of the MICOS complex), and Opa1, which showed poorer oxidative consumption rate and mitochondria with decreased mitochondrial length and volume. In combination, these data show the need to explore if loss of the MICOS complex in the heart may be involved in age-associated mitochondrial and cristae structural changes.NEW & NOTEWORTHY This article shows how mitochondria in murine cardiac changes, importantly elucidating age-related changes. It also is the first to show that the MICOS complex may play a role in outer membrane mitochondrial structure.
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Affiliation(s)
- Zer Vue
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, United States
| | - Kit Neikirk
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, United States
| | - Larry Vang
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, United States
| | - Edgar Garza-Lopez
- Department of Internal Medicine, University of Iowa, Iowa City, Iowa, United States
| | - Trace A Christensen
- Microscopy and Cell Analysis Core Facility, Mayo Clinic, Rochester, Minnesota, United States
| | - Jianqiang Shao
- Central Microscopy Research Facility, University of Iowa, Iowa City, Iowa, United States
| | - Jacob Lam
- Department of Internal Medicine, University of Iowa, Iowa City, Iowa, United States
| | - Heather K Beasley
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, United States
| | - Andrea G Marshall
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, United States
| | - Amber Crabtree
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, United States
| | - Josephs Anudokem
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, United States
| | - Benjamin Rodriguez
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, United States
| | - Benjamin Kirk
- Department of Internal Medicine, University of Iowa, Iowa City, Iowa, United States
| | - Serif Bacevac
- Department of Internal Medicine, University of Iowa, Iowa City, Iowa, United States
| | - Taylor Barongan
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, United States
| | - Bryanna Shao
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, United States
| | - Dominique C Stephens
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, United States
- Department of Life and Physical Sciences, Fisk University, Nashville, Tennessee, United States
| | - Kinuthia Kabugi
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, United States
| | - Ho-Jin Koh
- Department of Biological Sciences, Tennessee State University, Nashville, Tennessee, United States
| | - Alice Koh
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, United States
| | - Chantell S Evans
- Department of Cell Biology, Duke University School of Medicine, Durham, North Carolina, United States
| | - Brittany Taylor
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, Florida, United States
| | - Anilkumar K Reddy
- Department of Medicine, Baylor College of Medicine, Houston, Texas, United States
| | - Tyne Miller-Fleming
- Division of Genetic Medicine, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - Ky'Era V Actkins
- Division of Genetic Medicine, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - Elma Zaganjor
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, United States
| | - Nastaran Daneshgar
- Department of Pathology, Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States
| | - Sandra A Murray
- Department of Cell Biology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States
| | - Bret C Mobley
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - Steven M Damo
- Department of Life and Physical Sciences, Fisk University, Nashville, Tennessee, United States
| | - Jennifer A Gaddy
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, United States
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, United States
- Tennessee Valley Healthcare Systems, United States Department of Veterans Affairs, Nashville, Tennessee, United States
| | - Blake Riggs
- Department of Biology at San Francisco State University, San Francisco, California, United States
| | - Celestine Wanjalla
- Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - Annet Kirabo
- Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - Melanie McReynolds
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, State College, Pennsylvania, United States
| | - Jose A Gomez
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - Mark A Phillips
- Department of Integrative Biology, Oregon State University, Corvallis, Oregon, United States
| | - Vernat Exil
- Division of Cardiology, Department of Pediatrics, St. Louis University School of Medicine, St. Louis, Missouri, United States
- Department of Pediatrics, Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States
| | - Dao-Fu Dai
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States
| | - Antentor Hinton
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, United States
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6
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Koethe JR, Eeds A, Stewart LV, Haas DW, Hildreth JEK, Mallal S, Wanjalla C, Perkins J, Ahonkhai A, Dong X, Berhanu R, Dash C. The Tennessee Center for AIDS Research HIV Research Training Program for Minority High School and Undergraduate Students: Development, Implementation, and Early Outcomes. J Acquir Immune Defic Syndr 2023; 94:S42-S46. [PMID: 37707847 PMCID: PMC10503046 DOI: 10.1097/qai.0000000000003261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/15/2023]
Abstract
BACKGROUND The Southern region of the United States has the highest HIV incidence, and new infections disproportionately affect Black Americans. The Tennessee Center for AIDS Research (CFAR) Diversity, Equity, and Inclusion Pathway Initiative (CDEIPI) program supports the training of individuals from groups underrepresented in medicine and science in multiple areas of research to increase the pool of HIV-focused investigators at early educational and career stages. SETTING The Tennessee CFAR is a partnership between Vanderbilt University Medical Center, Meharry Medical College (one of the oldest historically Black medical colleges), Tennessee Department of Health, and Nashville Community AIDS Resources, Education and Services (a sophisticated community service organization, which emphasizes research training responsive to regional and national priorities). METHODS The Tennessee CFAR CDEIPI program leverages existing Vanderbilt University Medical Center and Meharry Medical College structured biomedical training programs for high school and undergraduate students to provide an intensive, mentored, HIV research experience augmented by CFAR resources situating this training within the broader history, scientific breadth, and societal and political aspects of the HIV epidemic. RESULTS The first year of the Tennessee CFAR CDEIPI program trained 3 high school and 3 undergraduate students from underrepresented in medicine and science backgrounds in basic, clinical/translational, and community-focused research projects with a diverse group of 9 mentors. All students completed the program, and evaluations yielded positive feedback regarding mentoring quality and effectiveness, and continued interest in HIV-related research. CONCLUSIONS The Tennessee CFAR CDEIPI program will continue to build upon experience from the first year to further contribute to national efforts to increase diversity in HIV-related research.
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Affiliation(s)
| | | | | | - David W. Haas
- Vanderbilt University Medical Center, Nashville, TN
- Meharry Medical College, Nashville TN
| | | | - Simon Mallal
- Vanderbilt University Medical Center, Nashville, TN
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7
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Stephens DC, Mungai M, Crabtree A, Beasley HK, Garza-Lopez E, Neikirk K, Bacevac S, Vang L, Vue Z, Vue N, Marshall AG, Turner K, Shao J, Murray S, Gaddy JA, Wanjalla C, Davis J, Damo S, Hinton AO. Creating Optimal Conditions for OPA1 Isoforms by Western Blot in Skeletal Muscle Cells and Tissue. bioRxiv 2023:2023.05.20.541601. [PMID: 37292669 PMCID: PMC10245902 DOI: 10.1101/2023.05.20.541601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
OPA1 is a dynamin-related GTPase that modulates various mitochondrial functions and is involved in mitochondrial morphology. There are eight different isoforms of OPA1 in humans and five different isoforms in mice that are expressed as short or long-form isoforms. These isoforms contribute to OPA1's ability to control mitochondrial functions. However, isolating OPA1 all long and short isoforms through western blot has been a difficult task. To address this issue, we outline an optimized western blot protocol to isolate 5 different isoforms of OPA1 on the basis of different antibodies. This protocol can be used to study changes in mitochondrial structure and function.
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Affiliation(s)
- Dominique C. Stephens
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
- Department of Life and Physical Sciences, Fisk University, Nashville, TN, 37232, USA
| | - Margaret Mungai
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
| | - Amber Crabtree
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
| | - Heather K. Beasley
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
| | - Edgar Garza-Lopez
- Department of Internal Medicine, University of Iowa, Iowa City, IA, 52242, USA
| | - Kit Neikirk
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
| | - Serif Bacevac
- Central Microscopy Research Facility, University of Iowa, Iowa City, IA, 52242, USA
| | - Larry Vang
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
| | - Zer Vue
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
| | - Neng Vue
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
| | - Andrea G. Marshall
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
| | - Kyrin Turner
- Department of Life and Physical Sciences, Fisk University, Nashville, TN, 37232, USA
| | - Jianqiang Shao
- Central Microscopy Research Facility, University of Iowa, Iowa City, IA, 52242, USA
| | - Sandra Murray
- Department of Cell Biology, College of Medicine, University of Pittsburgh, Pittsburgh, PA, 15260, USA
| | - Jennifer A. Gaddy
- Division of Infectious Diseases, Vanderbilt University School of Medicine, Nashville, TN, 37232, USA
- Tennessee Valley Healthcare Systems, U.S. Department of Veterans Affairs, Nashville, TN, 37212, USA
| | - Celestine Wanjalla
- Vanderbilt University Medical Center: Department of Medicine, Division of Infectious Disease, Nashville, TN, USA
| | - Jamaine Davis
- Department of Biochemistry and Cancer Biology. Meharry Medical College, Nashville, TN, 37208, USA
| | - Steven Damo
- Department of Life and Physical Sciences, Fisk University, Nashville, TN, 37232, USA
| | - Antentor O. Hinton
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
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8
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Stephens DC, Crabtree A, Beasley HK, Garza-Lopez E, Neikirk K, Mungai M, Vang L, Vue Z, Vue N, Marshall AG, Turner K, Shao J, Murray S, Gaddy JA, Wanjalla C, Davis J, Damo S, Hinton AO. Optimizing In Situ Proximity Ligation Assays for Mitochondria, ER, or MERC Markers in Skeletal Muscle Tissue and Cells. bioRxiv 2023:2023.05.20.541599. [PMID: 37292700 PMCID: PMC10245739 DOI: 10.1101/2023.05.20.541599] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Proximity ligation assays (PLA) use specific antibodies to detect endogenous protein-protein interactions. PLA is a highly useful biochemical technique that allows two proteins within close proximity to be visualized with fluorescent probes amplified by PCR. While this technique has gained prominence, the use of PLA in mouse skeletal muscle (SkM) is novel. In this article, we discuss how the PLA method can be used in SkM to study the protein-protein interactions within mitochondria-endoplasmic reticulum contact sites (MERCs).
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Affiliation(s)
- Dominique C. Stephens
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
- Department of Life and Physical Sciences, Fisk University, Nashville, TN, 37232, USA
| | - Amber Crabtree
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
| | - Heather K. Beasley
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
| | - Edgar Garza-Lopez
- Department of Internal Medicine, University of Iowa, Iowa City, IA, 52242, USA
| | - Kit Neikirk
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
| | - Margaret Mungai
- Department of Internal Medicine, University of Iowa, Iowa City, IA, 52242, USA
| | - Larry Vang
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
| | - Zer Vue
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
| | - Neng Vue
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
| | - Andrea G. Marshall
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
| | - Kyrin Turner
- Department of Life and Physical Sciences, Fisk University, Nashville, TN, 37232, USA
| | - Jianqiang Shao
- Central Microscopy Research Facility, University of Iowa, Iowa City, IA, 52242, USA
| | - Sandra Murray
- Department of Cell Biology, College of Medicine, University of Pittsburgh, Pittsburgh, PA, 15260, USA
| | - Jennifer A. Gaddy
- Division of Infectious Diseases, Vanderbilt University School of Medicine, Nashville, Tennessee, 37232 USA
- Tennessee Valley Healthcare Systems, U.S. Department of Veterans Affairs, Nashville, Tennessee, 37212 USA
| | - Celestine Wanjalla
- Vanderbilt University Medical Center: Department of Medicine, Division of Infectious Disease, Nashville, TN, USA
| | - Jamaine Davis
- Department of Biochemistry and Cancer Biology. Meharry Medical College, Nashville, TN, 37208, USA
| | - Steven Damo
- Department of Life and Physical Sciences, Fisk University, Nashville, TN, 37232, USA
| | - Antentor O. Hinton
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
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9
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Mays A, Byars-Winston A, Hinton A, Marshall AG, Kirabo A, August A, Marlin BJ, Riggs B, Tolbert B, Wanjalla C, Womack C, Evans CS, Barnes C, Starbird C, Williams C, Reynolds C, Taabazuing C, Cameron CE, Murray DD, Applewhite D, Morton DJ, Lee D, Williams DW, Lynch D, Brady D, Lynch E, Rutaganira FUN, Silva GM, Shuler H, Saboor IA, Davis J, Dzirasa K, Hammonds-Odie L, Reyes L, Sweetwyne MT, McReynolds MR, Johnson MDL, Smith NA, Pittman N, Ajijola OA, Smith Q, Robinson RAS, Lewis SC, Murray SA, Black S, Neal SE, Andrisse S, Townsend S, Damo SM, Griffith TN, Lambert WM, Clemons WM. Juneteenth in STEMM and the barriers to equitable science. Cell 2023; 186:2510-2517. [PMID: 37295396 DOI: 10.1016/j.cell.2023.05.016] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 05/06/2023] [Accepted: 05/12/2023] [Indexed: 06/12/2023]
Abstract
We are 52 Black scientists. Here, we establish the context of Juneteenth in STEMM and discuss the barriers Black scientists face, the struggles they endure, and the lack of recognition they receive. We review racism's history in science and provide institutional-level solutions to reduce the burdens on Black scientists.
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Affiliation(s)
- Alfred Mays
- Burroughs Wellcome Fund, Durham, NC 27709, USA
| | - Angela Byars-Winston
- Department of Medicine, Institute for Diversity Science, University of Wisconsin-Madison, Madison, WI 53715, USA
| | - Antentor Hinton
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232, USA.
| | - Andrea G Marshall
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232, USA
| | - Annet Kirabo
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232, USA; Department of Medicine, Division of Clinical Pharmacology, Vanderbilt University Medical Center, Vanderbilt University, Nashville, TN 37232, USA
| | - Avery August
- Department of Microbiology and Immunology, Cornell University College of Veterinary Medicine, Ithaca, NY 14853, USA
| | - Bianca J Marlin
- Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA; Department of Psychology, Columbia University, New York, NY 10032, USA; Department of Neuroscience, Columbia University, New York, NY 10027, USA
| | - Blake Riggs
- Department of Biology, San Francisco State University, San Francisco, CA 94132, USA
| | - Blanton Tolbert
- Department of Chemistry, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Celestine Wanjalla
- Division of Infectious Diseases, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Chad Womack
- National STEM Programs and Tech Initiatives at the education philanthropic charity, UNCF, Washington, DC 20001, USA
| | - Chantell S Evans
- Department of Cell Biology, Duke University Medical Center, Durham, NC 27708, USA
| | | | - Chrystal Starbird
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Clintoria Williams
- Department of Neuroscience, Cell Biology & Physiology, College of Science and Mathematics, Wright State University Boonshoft School of Medicine, Dayton, OH 45435, USA
| | - Corey Reynolds
- Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX 77030, USA; Mouse Phenotyping Core, Baylor College of Medicine, Houston, TX 77030, USA
| | - Cornelius Taabazuing
- Department of Biochemistry and Biophysics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Craig E Cameron
- Department of Microbiology and Immunology, School of Medicine, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Debra D Murray
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | | | - Derrick J Morton
- Department of Biological Sciences, University of Southern California Los Angeles, Los Angeles, CA 90089, USA
| | - Dexter Lee
- Department of Physiology and Biophysics, Howard University College of Medicine, Washington, DC 20059, USA
| | - Dionna W Williams
- Department of Molecular and Comparative Pathobiology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Donald Lynch
- Department of Medicine, Division of Cardiovascular Health and Disease, University of Cincinnati, Cincinnati, OH, USA
| | - Donita Brady
- Department of Cancer Biology, University of Pennsylvania, Philadelphia, PA 19104, USA; Abramson Family Cancer Research Institute, University of Pennsylvania, Philadelphia, PA 19104, USA; Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
| | - Erin Lynch
- University of Michigan Health System, Ann Arbor, MI 48109, USA
| | - Florentine U N Rutaganira
- Department of Biochemistry, Stanford University, Stanford, CA 94305, USA; Department of Developmental Biology, Stanford University, Stanford, CA 94305, USA
| | - Gustavo M Silva
- Department of Biology, Duke University, Durham, NC 27708, USA
| | - Haysetta Shuler
- Winston-Salem State University Department of Biological Sciences, Winston-Salem, NC 27110, USA
| | - Ishmail Abdus Saboor
- Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA; Department of Biological Sciences, Columbia University, New York, NY 10027, USA.
| | - Jamaine Davis
- Department of Biochemistry, Cancer Biology, Neuroscience, Pharmacology, Meharry Medical College, Nashville, TN 37232, USA; Center for Structural Biology, Vanderbilt University, Nashville, TN 37232, USA
| | - Kafui Dzirasa
- Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA; Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, NC 27710, USA; Department of Neurobiology, Duke University Medical Center, Durham, NC 27710, USA.
| | - Latanya Hammonds-Odie
- Department of Biological Sciences before School of Science and Technology, Georgia Gwinnett College, Lawrenceville, GA 30043, USA
| | - Loretta Reyes
- Division of Pediatric Nephrology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Mariya T Sweetwyne
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA 98195, USA
| | - Melanie R McReynolds
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, PA 16802, USA; Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA 16802, USA
| | - Michael D L Johnson
- Department of Immunobiology, University of Arizona, Tucson, AZ 85724, USA; BIO5 Institute, University of Arizona, Tucson, AZ 85724, USA; Valley Fever Center for Excellence, University of Arizona, Tucson, AZ, USA
| | - Nathan A Smith
- Del Monte Institute for Neuroscience, Department of Neuroscience, University of Rochester, School of Medicine and Dentistry, Rochester, NY 14642, USA
| | - Nikea Pittman
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Olujimi A Ajijola
- UCLA Cardiac Arrhythmia Center and Neurocardiology Research Program of Excellence, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, CA 90095, USA
| | - Quinton Smith
- School of Engineering, University of California, Irvine, CA 92697-3975, USA
| | - Renã A S Robinson
- Department of Chemistry, Vanderbilt University, Nashville, TN 37235, USA
| | - Samantha C Lewis
- Department of Molecular and Cellular Biology, University of California Berkeley, Berkeley, CA 94720, USA
| | - Sandra A Murray
- Department of Cell Biology, School of Medicine, University of Pittsburgh, Pittsburgh, PA 52013, USA.
| | - Sherilynn Black
- Office of the Provost and Division of Medical Education, Duke University, Durham, NC 27708, USA.
| | - Sonya E Neal
- Division of Biological Sciences, Section of Cell and Developmental Biology, University of California San Diego, La Jolla, CA 92093, USA
| | - Stanley Andrisse
- Department of Physiology and Biophysics, Howard University College of Medicine, Washington, DC 20059, USA; Department of Pediatrics, School of Medicine, Johns Hopkins University, Baltimore, MD 21287, USA
| | - Steven Townsend
- Department of Chemistry, Vanderbilt University, Nashville, TN 37235, USA
| | - Steven M Damo
- Center for Structural Biology, Vanderbilt University, Nashville, TN 37232, USA; Department of Life and Physical Sciences, Fisk University, Nashville, TN 37208, USA.
| | - Theanne N Griffith
- Department of Physiology and Membrane Biology, University of California Davis, Davis, CA 95616, USA
| | - W Marcus Lambert
- Department of Epidemiology and Biostatistics, SUNY Downstate Health Sciences University, New York, NY 11203, USA
| | - William M Clemons
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125, USA
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10
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Ransey E, Brookens S, Beasley HK, Marshall A, Marlin BJ, Rodriguez-Aliaga P, Headley CA, Wanjalla C, Vazquez AD, Murray S, Damo S, Taabazuing CY, Hinton A. A practical guide to graduate school interviewing for historically excluded individuals. Am J Physiol Heart Circ Physiol 2023; 324:H786-H790. [PMID: 37027327 PMCID: PMC10191121 DOI: 10.1152/ajpheart.00123.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 04/03/2023] [Accepted: 04/03/2023] [Indexed: 04/08/2023]
Affiliation(s)
- Elizabeth Ransey
- Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, North Carolina, United States
| | - Shawna Brookens
- Department of Pharmacology, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Heather K Beasley
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, United States
| | - Andrea Marshall
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, United States
| | - Bianca J Marlin
- Mortimer B. Zuckerman Mind Brain and Behavior Institute, Columbia University, New York, New York, United States
- Department of Psychology, Columbia University, New York, New York, United States
- Department of Neuroscience, Columbia University, New York, New York, United States
| | | | - Colwyn Ansel Headley
- Department of Cardiovascular Medicine, Stanford University, Stanford, California, United States
| | - Celestine Wanjalla
- Division of Infectious Diseases, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - Arnaldo Diaz Vazquez
- Department of Biomedical Sciences, University of Texas Southwestern Medical Center, Dallas, Texas, United States
| | - Sandra Murray
- Department of Cell Biology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States
| | - Steven Damo
- Department of Life and Physical Sciences, Fisk University, Nashville, Tennessee, United States
- Center for Structural Biology, Vanderbilt University, Nashville, Tennessee, United States
| | - Cornelius Y Taabazuing
- Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Antentor Hinton
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, United States
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11
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Gelbard A, Shilts MH, Strickland B, Motz K, Tsai HW, Boone H, Drake WP, Wanjalla C, Smith PM, Brown H, Ramierez M, Atkinson JB, Powell J, Simpson J, Rajagopala SV, Mallal S, Sheng Q, Hillel AT, Das SR. Idiopathic subglottic stenosis arises at the epithelial interface of host and pathogen. Res Sq 2023:rs.3.rs-2945067. [PMID: 37292825 PMCID: PMC10246274 DOI: 10.21203/rs.3.rs-2945067/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Background Idiopathic subglottic stenosis (iSGS) is a rare fibrotic disease of the proximal airway affecting adult Caucasian women nearly exclusively. Life-threatening ventilatory obstruction occurs secondary to pernicious subglottic mucosal scar. Disease rarity and wide geographic patient distribution has previously limited substantive mechanistic investigation into iSGS pathogenesis. Result By harnessing pathogenic mucosa from an international iSGS patient cohort and single-cell RNA sequencing, we unbiasedly characterize the cell subsets in the proximal airway scar and detail their molecular phenotypes. Results show that the airway epithelium in iSGS patients is depleted of basal progenitor cells, and the residual epithelial cells acquire a mesenchymal phenotype. Observed displacement of bacteria beneath the lamina propria provides functional support for the molecular evidence of epithelial dysfunction. Matched tissue microbiomes support displacement of the native microbiome into the lamina propria of iSGS patients rather than disrupted bacterial community structure. However, animal models confirm that bacteria are necessary for pathologic proximal airway fibrosis and suggest an equally essential role for host adaptive immunity. Human samples from iSGS airway scar demonstrate adaptive immune activation in response to the proximal airway microbiome of both matched iSGS patients and healthy controls. Clinical outcome data from iSGS patients suggests surgical extirpation of airway scar and reconstitution with unaffected tracheal mucosa halts the progressive fibrosis. Conclusion Our data support an iSGS disease model where epithelial alterations facilitate microbiome displacement, dysregulated immune activation, and localized fibrosis. These results refine our understanding of iSGS and implicate shared pathogenic mechanisms with distal airway fibrotic diseases.
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12
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Pitzer A, Elijovich F, Laffer CL, Ertuglu LA, Sahinoz M, Saleem M, Krishnan J, Dola T, Aden LA, Sheng Q, Raddatz MA, Wanjalla C, Pakala S, Davies SS, Patrick DM, Kon V, Ikizler TA, Kleyman T, Kirabo A. DC ENaC-Dependent Inflammasome Activation Contributes to Salt-Sensitive Hypertension. Circ Res 2022; 131:328-344. [PMID: 35862128 PMCID: PMC9357159 DOI: 10.1161/circresaha.122.320818] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Salt sensitivity of blood pressure is an independent predictor of cardiovascular morbidity and mortality. The exact mechanism by which salt intake increases blood pressure and cardiovascular risk is unknown. We previously found that sodium entry into antigen-presenting cells (APCs) via the amiloride-sensitive epithelial sodium channel EnaC (epithelial sodium channel) leads to the formation of IsoLGs (isolevuglandins) and release of proinflammatory cytokines to activate T cells and modulate salt-sensitive hypertension. In the current study, we hypothesized that ENaC-dependent entry of sodium into APCs activates the NLRP3 (NOD [nucleotide-binding and oligomerization domain]-like receptor family pyrin domain containing 3) inflammasome via IsoLG formation leading to salt-sensitive hypertension. METHODS We performed RNA sequencing on human monocytes treated with elevated sodium in vitro and Cellular Indexing of Transcriptomes and Epitopes by Sequencing analysis of peripheral blood mononuclear cells from participants rigorously phenotyped for salt sensitivity of blood pressure using an established inpatient protocol. To determine mechanisms, we analyzed inflammasome activation in mouse models of deoxycorticosterone acetate salt-induced hypertension as well as salt-sensitive mice with ENaC inhibition or expression, IsoLG scavenging, and adoptive transfer of wild-type dendritic cells into NLRP3 deficient mice. RESULTS We found that high levels of salt exposure upregulates the NLRP3 inflammasome, pyroptotic and apoptotic caspases, and IL (interleukin)-1β transcription in human monocytes. Cellular Indexing of Transcriptomes and Epitopes by Sequencing revealed that components of the NLRP3 inflammasome and activation marker IL-1β dynamically vary with changes in salt loading/depletion. Mechanistically, we found that sodium-induced activation of the NLRP3 inflammasome is ENaC and IsoLG dependent. NLRP3 deficient mice develop a blunted hypertensive response to elevated sodium, and this is restored by the adoptive transfer of NLRP3 replete APCs. CONCLUSIONS These findings reveal a mechanistic link between ENaC, inflammation, and salt-sensitive hypertension involving NLRP3 inflammasome activation in APCs. APC activation via the NLRP3 inflammasome can serve as a potential diagnostic biomarker for salt sensitivity of blood pressure.
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Affiliation(s)
- Ashley Pitzer
- Department of Medicine, Division of Clinical Pharmacology, Vanderbilt University Medical Center Nashville, TN, USA
| | - Fernando Elijovich
- Department of Medicine, Division of Clinical Pharmacology, Vanderbilt University Medical Center Nashville, TN, USA
| | - Cheryl L. Laffer
- Department of Medicine, Division of Clinical Pharmacology, Vanderbilt University Medical Center Nashville, TN, USA
| | - Lale A. Ertuglu
- Department of Medicine, Division of Nephrology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Melis Sahinoz
- Department of Medicine, Division of Nephrology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Mohammad Saleem
- Department of Medicine, Division of Clinical Pharmacology, Vanderbilt University Medical Center Nashville, TN, USA
| | - Jaya Krishnan
- Department of Medicine, Division of Clinical Pharmacology, Vanderbilt University Medical Center Nashville, TN, USA
| | - Thanvi Dola
- Department of Medicine, Division of Clinical Pharmacology, Vanderbilt University Medical Center Nashville, TN, USA
| | - Luul A Aden
- Department of Medicine, Division of Clinical Pharmacology, Vanderbilt University Medical Center Nashville, TN, USA
| | - Quanhu Sheng
- Department of Biostatistics, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Michael A. Raddatz
- Medical Scientist Training Program, Vanderbilt University, Nashville, TN, USA
- Department of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Celestine Wanjalla
- Department of Internal Medicine, Division of Infectious Diseases, Vanderbilt University Medical Center Nashville, TN, USA
| | - Suman Pakala
- Department of Internal Medicine, Division of Infectious Diseases, Vanderbilt University Medical Center Nashville, TN, USA
| | - Sean S Davies
- Department of Pharmacology, Vanderbilt University, Nashville, TN, USA
- Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, TN, USA
| | - David M Patrick
- Department of Medicine, Division of Clinical Pharmacology, Vanderbilt University Medical Center Nashville, TN, USA
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Department of Medicine, Division of Cardiovascular Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | | | - T. Alp Ikizler
- Department of Medicine, Division of Nephrology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Thomas Kleyman
- Departments of Medicine, Cell Biology, Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Annet Kirabo
- Department of Medicine, Division of Clinical Pharmacology, Vanderbilt University Medical Center Nashville, TN, USA
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13
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Norwood J, Kheshti A, Shepherd BE, Rebeiro PF, Ahonkhai A, Kelly S, Wanjalla C. The Impact of COVID-19 on the HIV Care Continuum in a Large Urban Southern Clinic. AIDS Behav 2022; 26:2825-2829. [PMID: 35194699 PMCID: PMC8863570 DOI: 10.1007/s10461-022-03615-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/05/2022] [Indexed: 11/18/2022]
Abstract
Access to care is essential for people with HIV (PWH) but may have been affected during the COVID-19 pandemic. We conducted a retrospective cross-sectional study of adult PWH receiving care in a large southeastern comprehensive care clinic in the United States. Patients in care between January 1, 2017, and July 30, 2020, were included. Race/ethnicity, sex, HIV-1 RNA, CD4 + lymphocyte count were included as baseline covariates. Outcomes included clinic attendance, receipt of HIV-1 RNA PCR testing, and virologic suppression (HIV-1 RNA < 200 copies/mL); outpatient encounters included new patient encounters, follow-up visits, and mental health encounters. Total medical encounters, including telemedicine, decreased by 827 visits (33%) when comparing the second quarters of 2019 and 2020. New patient encounters decreased by 23.5% from 81 to 62 during this period. The second quarter of 2020 saw the lowest number of new patient visits since 2017. HIV-1 RNA testing and the proportion of patients with virologic suppression decreased during the pandemic (p < 0.001 for both). Total mental health encounters, on the other hand, increased by 14% during April-June 2020 compared to April-June 2019. Mental health electronic communications increased by 60% from 312 to 500 during the same period, with a 20% increase in medication refills. The COVID-19 pandemic affected outpatient visits, viral load surveillance, and virologic suppression but led to an increase in mental health encounters in a comprehensive care clinic setting.
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Affiliation(s)
- Jamison Norwood
- Division of Infectious Disease, Department of Medicine, Vanderbilt University Medical Center, A-2200 MCN, 1161 21st Ave S., Nashville, TN, 37232-2582, USA.
| | - Asghar Kheshti
- Division of Infectious Disease, Department of Medicine, Vanderbilt University Medical Center, A-2200 MCN, 1161 21st Ave S., Nashville, TN, 37232-2582, USA
| | - Bryan E Shepherd
- Department of Biostatistics, Vanderbilt University, Nashville, TN, USA
| | - Peter F Rebeiro
- Division of Infectious Disease, Department of Medicine, Vanderbilt University Medical Center, A-2200 MCN, 1161 21st Ave S., Nashville, TN, 37232-2582, USA
- Department of Biostatistics, Vanderbilt University, Nashville, TN, USA
| | - Aimalohi Ahonkhai
- Division of Infectious Disease, Department of Medicine, Vanderbilt University Medical Center, A-2200 MCN, 1161 21st Ave S., Nashville, TN, 37232-2582, USA
| | - Sean Kelly
- Division of Infectious Disease, Department of Medicine, Vanderbilt University Medical Center, A-2200 MCN, 1161 21st Ave S., Nashville, TN, 37232-2582, USA
| | - Celestine Wanjalla
- Division of Infectious Disease, Department of Medicine, Vanderbilt University Medical Center, A-2200 MCN, 1161 21st Ave S., Nashville, TN, 37232-2582, USA.
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14
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Temu TM, Macharia P, Mtui J, Mwangi M, Ngungi PW, Wanjalla C, Bloomfield GS, Farquhar C, Nyanjau L, Gathecha GK, Kibachio J. Obesity and risk for hypertension and diabetes among Kenyan adults: Results from a national survey. Medicine (Baltimore) 2021; 100:e27484. [PMID: 34622879 PMCID: PMC8500651 DOI: 10.1097/md.0000000000027484] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Revised: 09/21/2021] [Accepted: 09/23/2021] [Indexed: 01/05/2023] Open
Abstract
ABSTRACT Despite the anticipated growth in the global burden of obesity especially in low-income countries, limited data exist on the contribution of obesity to cardiometabolic diseases in Africa.We examined population-based samples of Kenyan adults who participated in the 2015 national chronic disease risk factor surveillance survey. Weight and height were measured, and body mass index (BMI) was calculated and used as a measure for general obesity. Waist circumference (WC), a clinical measure of central obesity was also measured. Logistic regression was used to assess the association between obesity with hypertension, diabetes, and dyslipidemia risk.Of the 4276 participants, the median (IQR) age was 36 (27-47) years, 41% were men. One-third (37%) of the participants were centrally obese, whereas 10% were generally obese. The odds for overweight and general obesity were highest among females, adults >40 years, and those in the highest wealth quartile. Central and general obesity, assessed by WC and BMI, were associated with hypertension and dyslipidemia but not diabetes for both sexes. Compared with adults of normal weight, individuals with a BMI of ≥30 kg/m2 had an odds ratio of 2.39 (95% confidence interval [CI], 1.82-3.12) for hypertension and 2.24 (95% CI, 1.70-2.96) for dyslipidemia.Obesity prevalence is high in Kenya and is associated with hypertension and dyslipidemia but not diabetes. Our findings indicate an urgent need to develop public health interventions to address obesity and prevent the development of comorbid conditions.
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Affiliation(s)
- Tecla M Temu
- Department of Global Health, University of Washington, Seattle, WA
- Institute of Tropical Diseases, University of Nairobi, Nairobi, Kenya
| | | | - James Mtui
- Saint George University, University Center, Grenada, West Indies
| | | | | | | | - Gerald S Bloomfield
- Duke Global Health Institute, Duke Clinical Research Institute, Department of Medicine, Duke University, Durham, NC
| | - Carey Farquhar
- Department of Global Health, University of Washington, Seattle, WA
- Department of Medicine and Epidemiology, University of Washington, Seattle, WA
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15
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Gabriel CL, Ye F, Fan R, Nair S, Terry JG, Carr JJ, Silver H, Baker P, Hannah L, Wanjalla C, Mashayekhi M, Bailin S, Lima M, Woodward B, Izzy M, Ferguson JF, Koethe JR. Hepatic Steatosis and Ectopic Fat Are Associated With Differences in Subcutaneous Adipose Tissue Gene Expression in People With HIV. Hepatol Commun 2021; 5:1224-1237. [PMID: 34278171 PMCID: PMC8279464 DOI: 10.1002/hep4.1695] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 01/20/2021] [Accepted: 01/29/2021] [Indexed: 01/03/2023] Open
Abstract
Persons with human immunodeficiency virus (PWH) have subcutaneous adipose tissue (SAT) dysfunction related to antiretroviral therapy and direct viral effects, which may contribute to a higher risk of nonalcoholic fatty liver disease compared with human immunodeficiency virus-negative individuals. We assessed relationships between SAT expression of major adipocyte regulatory and lipid storage genes with hepatic and other ectopic lipid deposits in PWH. We enrolled 97 PWH on long-term antiretroviral therapy with suppressed plasma viremia and performed computed tomography measurements of liver attenuation, a measure of hepatic steatosis, skeletal muscle (SM) attenuation, and the volume of abdominal subcutaneous, visceral, and pericardial adipose tissue. Whole SAT gene expression was measured using the Nanostring platform, and relationships with computed tomography imaging and fasting lipids were assessed using multivariable linear regression and network mapping. The cohort had a mean age of 47 years, body mass index of 33.4 kg/m2, and CD4 count of 492 cells/mm3. Lower liver attenuation, a marker of greater steatosis, was associated with differences in SAT gene expression, including lower lipoprotein lipase and acyl-CoA dehydrogenase, and higher phospholipid transfer protein. Lower liver attenuation clustered with lower visceral adipose tissue (VAT) attenuation and greater VAT volume, pericardial fat volume and triglycerides, but no relationship was observed between liver attenuation and SAT volume, SM attenuation, or low-density lipoprotein. Conclusion: Liver attenuation was associated with altered SAT expression of genes regulating lipid metabolism and storage, suggesting that SAT dysfunction may contribute to nonalcoholic fatty liver disease in PWH. SAT gene-expression relationships were similar for VAT volume and attenuation, but not SM, indicating that ectopic lipid deposition may involve multiple pathways.
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Affiliation(s)
- Curtis L. Gabriel
- Division of Gastroenterology, Hepatology and NutritionVanderbilt University Medical CenterNashvilleTNUSA
- Tennessee Center for AIDS ResearchVanderbilt University Medical CenterNashvilleTNUSA
| | - Fei Ye
- Department of BiostatisticsVanderbilt University Medical CenterNashvilleTNUSA
| | - Run Fan
- Department of BiostatisticsVanderbilt University Medical CenterNashvilleTNUSA
| | - Sangeeta Nair
- Department of Radiology and Radiological SciencesVanderbilt University Medical CenterNashvilleTNUSA
| | - James G. Terry
- Department of Radiology and Radiological SciencesVanderbilt University Medical CenterNashvilleTNUSA
| | - John Jeffrey Carr
- Department of Radiology and Radiological SciencesVanderbilt University Medical CenterNashvilleTNUSA
| | - Heidi Silver
- Division of Gastroenterology, Hepatology and NutritionVanderbilt University Medical CenterNashvilleTNUSA
- Veterans Affairs Tennessee Valley Healthcare SystemNashvilleTNUSA
| | - Paxton Baker
- Vanderbilt Technologies for Advanced GenomicsVanderbilt University Medical CenterNashvilleTNUSA
| | - LaToya Hannah
- Division of Diabetes, Endocrinology and MetabolismVanderbilt University Medical CenterNashvilleTNUSA
| | - Celestine Wanjalla
- Tennessee Center for AIDS ResearchVanderbilt University Medical CenterNashvilleTNUSA
- Division of Infectious DiseasesVanderbilt University Medical CenterNashvilleTNUSA
| | - Mona Mashayekhi
- Division of Diabetes, Endocrinology and MetabolismVanderbilt University Medical CenterNashvilleTNUSA
| | - Sam Bailin
- Division of Infectious DiseasesVanderbilt University Medical CenterNashvilleTNUSA
| | - Morgan Lima
- Tennessee Center for AIDS ResearchVanderbilt University Medical CenterNashvilleTNUSA
| | - Beverly Woodward
- Tennessee Center for AIDS ResearchVanderbilt University Medical CenterNashvilleTNUSA
| | - Manhal Izzy
- Division of Gastroenterology, Hepatology and NutritionVanderbilt University Medical CenterNashvilleTNUSA
| | - Jane F. Ferguson
- Division of Cardiovascular MedicineVanderbilt University Medical CenterNashvilleTNUSA
| | - John R. Koethe
- Tennessee Center for AIDS ResearchVanderbilt University Medical CenterNashvilleTNUSA
- Veterans Affairs Tennessee Valley Healthcare SystemNashvilleTNUSA
- Division of Infectious DiseasesVanderbilt University Medical CenterNashvilleTNUSA
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16
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Gelbard A, Wanjalla C, Wootten CT, Drake WP, Lowery AS, Wheeler DA, Cardenas MF, Sikora AG, Pathak RR, McDonnell W, Mallal S, Pilkinton M. The Proximal Airway Is a Reservoir for Adaptive Immunologic Memory in Idiopathic Subglottic Stenosis. Laryngoscope 2021; 131:610-617. [PMID: 32603507 PMCID: PMC7951501 DOI: 10.1002/lary.28840] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 05/18/2020] [Accepted: 05/21/2020] [Indexed: 01/20/2023]
Abstract
OBJECTIVES/HYPOTHESIS Characterization of the localized adaptive immune response in the airway scar of patients with idiopathic subglottic stenosis (iSGS). STUDY DESIGN Basic Science. METHODS Utilizing 36 patients with subglottic stenosis (25 idiopathic subglottic stenosis [iSGS], 10 iatrogenic post-intubation stenosis [iLTS], and one granulomatosis with polyangiitis [GPA]) we applied immunohistochemical and immunologic techniques coupled with RNA sequencing. RESULTS iSGS, iLTS, and GPA demonstrate a significant immune infiltrate in the subglottic scar consisting of adaptive cell subsets (T cells along with dendritic cells). Interrogation of T cell subtypes showed significantly more CD69+ CD103+ CD8+ tissue resident memory T cells (TRM ) in the iSGS airway scar than iLTS specimens (iSGS vs. iLTS; 50% vs. 28%, P = .0065). Additionally, subglottic CD8+ clones possessed T-cell receptor (TCR) sequences with known antigen specificity for viral and intracellular pathogens. CONCLUSIONS The human subglottis is significantly enriched for CD8+ tissue resident memory T cells in iSGS, which possess TCR sequences proven to recognize viral and intracellular pathogens. These results inform our understanding of iSGS, provide a direction for future discovery, and demonstrate immunologic function in the human proximal airway. Laryngoscope, 131:610-617, 2021.
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Affiliation(s)
- Alexander Gelbard
- Dept. of Otolaryngology-Head & Neck Surgery, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Celestine Wanjalla
- Dept. of Medicine, Division of Infectious Disease, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Christopher T. Wootten
- Dept. of Otolaryngology-Head & Neck Surgery, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Wonder P. Drake
- Dept. of Molecular and Human Genetics, Baylor College of Medicine, Houston Texas
| | - Anne S Lowery
- Dept. of Otolaryngology-Head & Neck Surgery, Vanderbilt University Medical Center, Nashville, Tennessee
| | - David A. Wheeler
- Dept. of Molecular and Human Genetics, Baylor College of Medicine, Houston Texas
| | - Maria F. Cardenas
- Dept. of Molecular and Human Genetics, Baylor College of Medicine, Houston Texas
| | - Andrew G. Sikora
- Bobby R. Alford Dept. of Otolaryngology-Head & Neck Surgery, Baylor College of Medicine, Houston Texas
| | - Ravi R. Pathak
- Bobby R. Alford Dept. of Otolaryngology-Head & Neck Surgery, Baylor College of Medicine, Houston Texas
| | | | - Simon Mallal
- Dept. of Molecular and Human Genetics, Baylor College of Medicine, Houston Texas
| | - Mark Pilkinton
- Dept. of Medicine, Division of Infectious Disease, Vanderbilt University Medical Center, Nashville, Tennessee
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17
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Bailin SS, McGinnis KA, McDonnell WJ, So-Armah K, Wellons M, Tracy RP, Doyle MF, Mallal S, Justice AC, Freiberg MS, Landay AL, Wanjalla C, Koethe JR. T Lymphocyte Subsets Associated With Prevalent Diabetes in Veterans With and Without Human Immunodeficiency Virus. J Infect Dis 2020; 222:252-262. [PMID: 32052044 PMCID: PMC7323499 DOI: 10.1093/infdis/jiaa069] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Accepted: 02/07/2020] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND A higher proportion of circulating memory CD4+ T cells is associated with prevalent diabetes mellitus in the general population. Given the broad changes in adaptive immunity, including memory T-cell expansion, and rising prevalence of diabetes in the human immunodeficiency virus (HIV) population, we assessed whether similar relationships were present in persons with HIV (PWH). METHODS Multiple CD4+ and CD8+ T-cell subsets were measured by flow cytometry, and prevalent diabetes cases were adjudicated by 2 physicians for PWH and HIV-negative participants in the Veterans Aging Cohort Study. Multivariable logistic regression models evaluated the association of T-cell subsets and diabetes stratified by HIV status, adjusted for cytomegalovirus serostatus and traditional risk factors. RESULTS Among 2385 participants (65% PWH, 95% male, 68% African American), higher CD45RO+ memory CD4+ T cells and lower CD38+ CD4+ T cells were associated with prevalent diabetes, and had a similar effect size, in both the PWH and HIV-negative (P ≤ .05 for all). Lower CD38+CD8+ T cells were also associated with diabetes in both groups. CONCLUSIONS The CD4+ and CD8+ T-cell subsets associated with diabetes are similar in PWH and HIV-negative individuals, suggesting that diabetes in PWH may be related to chronic immune activation.
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Affiliation(s)
- Samuel S Bailin
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Kathleen A McGinnis
- Veterans Affairs Connecticut Healthcare System, West Haven, Connecticut, USA
| | - Wyatt J McDonnell
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Kaku So-Armah
- Boston University School of Medicine, Boston, Massachusetts, USA
| | - Melissa Wellons
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Russell P Tracy
- Department of Pathology and Laboratory Medicine, University of Vermont, Burlington, Vermont, USA
| | - Margaret F Doyle
- Department of Pathology and Laboratory Medicine, University of Vermont, Burlington, Vermont, USA
| | - Simon Mallal
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Amy C Justice
- Veterans Affairs Connecticut Healthcare System, West Haven, Connecticut, USA
- Department of Internal Medicine, Yale School of Medicine, West Haven, Connecticut, USA
| | - Matthew S Freiberg
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Veterans Affairs Tennessee Valley Healthcare System, Nashville, Tennessee, USA
| | - Alan L Landay
- Department of Internal Medicine, Rush University Medical Center, Chicago, Illinois, USA
| | - Celestine Wanjalla
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - John R Koethe
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Veterans Affairs Tennessee Valley Healthcare System, Nashville, Tennessee, USA
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18
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Abstract
Adverse drug reactions (ADRs) are a significant source of patient morbidity and mortality and represent a major burden to health care systems and drug development. Up to 50% of such reactions are preventable. Although many ADRs can be predicted based on the on-target pharmacologic activity, ADRs arising from drug interactions with off-target receptors are recognized. Off-target ADRs include the immune-mediated ADRs (IM-ADRs) and pharmacologic drug effects. In this review, we discuss what is known about the immunogenetics and pathogenesis of IM-ADRs and the hypothesized role of heterologous immunity in the development of IM-ADRs.
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Affiliation(s)
- Rebecca Pavlos
- Institute for Immunology and Infectious Diseases, Murdoch University, 6150 Murdoch, Western Australia, Australia
| | - Katie D White
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Celestine Wanjalla
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Simon A Mallal
- Institute for Immunology and Infectious Diseases, Murdoch University, 6150 Murdoch, Western Australia, Australia; Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA; Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Elizabeth J Phillips
- Institute for Immunology and Infectious Diseases, Murdoch University, 6150 Murdoch, Western Australia, Australia; Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA; Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA; Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN, USA.
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19
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Abana CO, Pilkinton MA, Gaudieri S, Chopra A, McDonnell WJ, Wanjalla C, Barnett L, Gangula R, Hager C, Jung DK, Engelhardt BG, Jagasia MH, Klenerman P, Phillips EJ, Koelle DM, Kalams SA, Mallal SA. Cytomegalovirus (CMV) Epitope-Specific CD4 + T Cells Are Inflated in HIV + CMV + Subjects. J Immunol 2017; 199:3187-3201. [PMID: 28972094 DOI: 10.4049/jimmunol.1700851] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Accepted: 08/28/2017] [Indexed: 01/24/2023]
Abstract
Select CMV epitopes drive life-long CD8+ T cell memory inflation, but the extent of CD4 memory inflation is poorly studied. CD4+ T cells specific for human CMV (HCMV) are elevated in HIV+ HCMV+ subjects. To determine whether HCMV epitope-specific CD4+ T cell memory inflation occurs during HIV infection, we used HLA-DR7 (DRB1*07:01) tetramers loaded with the glycoprotein B DYSNTHSTRYV (DYS) epitope to characterize circulating CD4+ T cells in coinfected HLA-DR7+ long-term nonprogressor HIV subjects with undetectable HCMV plasma viremia. DYS-specific CD4+ T cells were inflated among these HIV+ subjects compared with those from an HIV- HCMV+ HLA-DR7+ cohort or with HLA-DR7-restricted CD4+ T cells from the HIV-coinfected cohort that were specific for epitopes of HCMV phosphoprotein-65, tetanus toxoid precursor, EBV nuclear Ag 2, or HIV gag protein. Inflated DYS-specific CD4+ T cells consisted of effector memory or effector memory-RA+ subsets with restricted TCRβ usage and nearly monoclonal CDR3 containing novel conserved amino acids. Expression of this near-monoclonal TCR in a Jurkat cell-transfection system validated fine DYS specificity. Inflated cells were polyfunctional, not senescent, and displayed high ex vivo levels of granzyme B, CX3CR1, CD38, or HLA-DR but less often coexpressed CD38+ and HLA-DR+ The inflation mechanism did not involve apoptosis suppression, increased proliferation, or HIV gag cross-reactivity. Instead, the findings suggest that intermittent or chronic expression of epitopes, such as DYS, drive inflation of activated CD4+ T cells that home to endothelial cells and have the potential to mediate cytotoxicity and vascular disease.
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Affiliation(s)
- Chike O Abana
- Department of Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, TN 37232
| | - Mark A Pilkinton
- Division of Infectious Diseases, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232
| | - Silvana Gaudieri
- Division of Infectious Diseases, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232.,School of Human Sciences, University of Western Australia, Perth, Western Australia 6009, Australia.,Institute for Immunology and Infectious Diseases, Murdoch University, Murdoch, Western Australia 6150, Australia
| | - Abha Chopra
- Institute for Immunology and Infectious Diseases, Murdoch University, Murdoch, Western Australia 6150, Australia
| | - Wyatt J McDonnell
- Department of Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, TN 37232
| | - Celestine Wanjalla
- Division of Infectious Diseases, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232
| | - Louise Barnett
- Division of Infectious Diseases, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232
| | - Rama Gangula
- Division of Infectious Diseases, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232
| | - Cindy Hager
- Division of Infectious Diseases, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232
| | - Dae K Jung
- Stem Cell Transplantation, Division of Hematology/Oncology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232
| | - Brian G Engelhardt
- Stem Cell Transplantation, Division of Hematology/Oncology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232
| | - Madan H Jagasia
- Stem Cell Transplantation, Division of Hematology/Oncology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232
| | - Paul Klenerman
- Peter Medawar Building for Pathogen Research, University of Oxford, Oxford OX1 3SY, United Kingdom; and
| | - Elizabeth J Phillips
- Department of Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, TN 37232.,Division of Infectious Diseases, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232.,Institute for Immunology and Infectious Diseases, Murdoch University, Murdoch, Western Australia 6150, Australia
| | - David M Koelle
- Department of Medicine, Laboratory Medicine, and Global Health, University of Washington, Seattle, WA 98195
| | - Spyros A Kalams
- Department of Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, TN 37232.,Division of Infectious Diseases, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232
| | - Simon A Mallal
- Department of Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, TN 37232; .,Division of Infectious Diseases, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232.,Institute for Immunology and Infectious Diseases, Murdoch University, Murdoch, Western Australia 6150, Australia
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20
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Affiliation(s)
- Kevin Kuriakose
- Department of Medicine, Division of Infectious Diseases, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Kelly Carpenter
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Celestine Wanjalla
- Department of Medicine, Division of Infectious Diseases, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - April Pettit
- Department of Medicine, Division of Infectious Diseases, Vanderbilt University Medical Center, Nashville, Tennessee, USA
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21
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Temu TM, Kirui N, Wanjalla C, Ndungu AM, Kamano JH, Inui TS, Bloomfield GS. Cardiovascular health knowledge and preventive practices in people living with HIV in Kenya. BMC Infect Dis 2015; 15:421. [PMID: 26466584 PMCID: PMC4607097 DOI: 10.1186/s12879-015-1157-8] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Accepted: 09/29/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Traditional cardiovascular disease (CVD) risk factors contribute to increase risk of CVD in people living with HIV (PLWH). Of all world regions, sub-Saharan Africa has the highest prevalence of HIV yet little is known about PLWH's CVD knowledge and self- perceived risk for coronary heart disease (CHD). In this study, we assessed PLWH's knowledge, perception and attitude towards cardiovascular diseases and their prevention. METHODS We conducted a cross-sectional study in the largest HIV care program in western Kenya. Trained research assistants used validated questionnaires to assess CVD risk patterns. We used logistic regression analysis to identify associations between knowledge with demographic variables, HIV disease characteristics, and individuals CVD risk patterns. RESULTS There were 300 participants in the study; median age (IQR) was 40 (33-46) years and 64 % women. The prevalence of dyslipidemia, overweight and obesity were 70 %, 33 % and 8 %, respectively. Participant's knowledge of risk factors was low with a mean (SD) score of 1.3 (1.3) out of possible 10. Most (77.7 %) could not identify any warning signs for heart attack. Higher education was a strong predictor of CVD risk knowledge (6.72, 95 % CI 1.98-22.84, P < 0.0001). Self-risk perception towards CHD was low (31 %) and majority had inappropriate attitude towards CVD risk reduction. CONCLUSION Despite a high burden of cardiovascular risk factors, PLWH in Kenya lack CVD knowledge and do not perceived themselves at risk for CHD. These results emphasis the need for behavior changes interventions to address the stigma and promote positive health behaviors among the high risk HIV population in Kenya.
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Affiliation(s)
- Tecla M. Temu
- Department of Medicine, School of Medicine, College of Health Sciences, Moi University, Eldoret, Kenya
- Department of Epidemiology, Brown University School of Public Health, Providence, RI USA
| | - Nicholas Kirui
- Department of Medicine, School of Medicine, College of Health Sciences, Moi University, Eldoret, Kenya
- Division of Medicine, Moi Teaching and Referral Hospital, Eldoret, Kenya
| | | | - Alfred M. Ndungu
- Department of Statistics, North Dakota State University, Fargo, ND USA
| | - Jemima H. Kamano
- Department of Medicine, School of Medicine, College of Health Sciences, Moi University, Eldoret, Kenya
- AMPATH Partnership, Eldoret, Kenya
- Division of Medicine, Moi Teaching and Referral Hospital, Eldoret, Kenya
| | - Thomas S. Inui
- Department of Medicine, School of Medicine, College of Health Sciences, Moi University, Eldoret, Kenya
- AMPATH Partnership, Eldoret, Kenya
- Division of Medicine, Moi Teaching and Referral Hospital, Eldoret, Kenya
- Department of Medicine, Indiana University, Indianapolis, USA
| | - Gerald S. Bloomfield
- Department of Medicine, Duke Clinical Research Institute and Duke Global Health Institute, Duke University, Durham, NC USA
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22
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Mareeva T, Wanjalla C, Schnell MJ, Sykulev Y. A novel composite immunotoxin that suppresses rabies virus production by the infected cells. J Immunol Methods 2010; 353:78-86. [PMID: 19932697 PMCID: PMC2823984 DOI: 10.1016/j.jim.2009.11.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2009] [Revised: 11/01/2009] [Accepted: 11/10/2009] [Indexed: 10/20/2022]
Abstract
Using strepavidin as a scaffold, we have assembled a composite immunotoxin that consists of recombinant Pseudomonas exotoxin A subunit (PE38) and recombinant 25-D1.16 Fab fragment which recognizes the SIINFEKL (pOV8) peptide from ovalbumin in association with H-2K(b) MHC class I protein. The composite immunotoxin exercises cytotoxicity against H-2K(b+) cells sensitized with pOV8 peptide but not with irrelevant peptide. Specific binding of the immunotoxin to H-2K(b+) cells infected with recombinant rabies virus (RV) expressing pOV8 epitope (RV-pOV8) resulted in the suppression of the production of virus particles by the infected cells. This strategy allows readily produce different immunotoxins with desired specificity by combining various targeting and toxin molecules. The results provide a proof of concept that composite immunotoxins can be utilized as novel immunotherapeutics to stop virus spread in the acute phase of the infection allowing winning time for the development of protective immune response.
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Affiliation(s)
- Tatiana Mareeva
- Department of Microbiology and Immunology, Thomas Jefferson University, Philadelphia, PA19107
| | - Celestine Wanjalla
- Department of Microbiology and Immunology, Thomas Jefferson University, Philadelphia, PA19107
| | - Matthias J. Schnell
- Department of Microbiology and Immunology, Thomas Jefferson University, Philadelphia, PA19107
- Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA19107
- Jefferson Vaccine Center, Thomas Jefferson University, Philadelphia, PA19107
| | - Yuri Sykulev
- Department of Microbiology and Immunology, Thomas Jefferson University, Philadelphia, PA19107
- Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA19107
- Jefferson Vaccine Center, Thomas Jefferson University, Philadelphia, PA19107
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23
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Regelmann AG, Danzl NM, Wanjalla C, Alexandropoulos K. The hematopoietic isoform of Cas-Hef1-associated signal transducer regulates chemokine-induced inside-out signaling and T cell trafficking. Immunity 2007; 25:907-18. [PMID: 17174122 DOI: 10.1016/j.immuni.2006.09.014] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2005] [Revised: 08/23/2006] [Accepted: 09/29/2006] [Indexed: 11/22/2022]
Abstract
Leukocyte migration and trafficking is dynamically regulated by various chemokine and adhesion molecules and is vital to the proper function of the immune system. We describe a role for the Cas and Hef-1-associated signal transducer in hematopoietic cells (Chat-H) as a critical regulator of T lymphocyte migration, by using lentivirus-mediated RNA interference (RNAi). Impaired migration of Chat-H-depleted cells coincided with defective inside-out signaling shown by diminished chemokine-induced activation of the Rap-1 GTPase and integrin-mediated adhesion. Localization of Chat-H to the plasma membrane, association with its binding partner Crk-associated substrate in lymphocytes (CasL), and Chat-H-mediated CasL serine-threonine phosphorylation were required for T cell migration. These results identify Chat-H as a critical signaling intermediate acting upstream of Rap1 to regulate chemokine-induced adhesion and migration.
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Affiliation(s)
- Adam G Regelmann
- The Integrated Program in Cellular, Molecular, and Biophysical Studies, College of Physicians and Surgeons of Columbia University, 630 West 168th Street, New York, New York 10032, USA
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Donlin LT, Danzl NM, Wanjalla C, Alexandropoulos K. Deficiency in expression of the signaling protein Sin/Efs leads to T-lymphocyte activation and mucosal inflammation. Mol Cell Biol 2006; 25:11035-46. [PMID: 16314525 PMCID: PMC1316950 DOI: 10.1128/mcb.25.24.11035-11046.2005] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Our studies have concentrated on elucidating the role of the signaling protein Sin in T-lymphocyte function. We have previously shown that Sin overexpression inhibits T-lymphocyte development and activation. Here we show that Sin-deficient mice exhibit exaggerated immune responses characterized by enhanced cytokine secretion and T-cell-dependent antibody production. Excessive T-cell responses in young mice correlate with spontaneous development of inflammatory lesions in different organs of aged Sin(-/-) mice, particularly the small intestine. The intestinal inflammation is characterized by T- and B-cell infiltrates in the lamina propria, which correlate with crypt enlargement and marked villus expansion and/or damage. Similar to the human intestinal inflammatory disorder Crohn's disease (CD), and in contrast to most mouse models of mucosal inflammation, inflammatory lesions in the gastrointestinal tract of Sin(-/-) mice are restricted to the small bowel. Taken together, these results suggest that Sin regulates immune system and T-lymphocyte function and that immune system dysfunction in the absence of Sin may underlie the pathogenesis of tissue-specific inflammation and enteropathies such as CD.
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Affiliation(s)
- Laura T Donlin
- Department of Pharmacology, College of Physicians and Surgeons of Columbia University, New York, NY 10032, USA
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Narayan M, Xu G, Ripoll DR, Zhai H, Breuker K, Wanjalla C, Leung HJ, Navon A, Welker E, McLafferty FW, Scheraga HA. Dissimilarity in the Reductive Unfolding Pathways of Two Ribonuclease Homologues. J Mol Biol 2004; 338:795-809. [PMID: 15099746 DOI: 10.1016/j.jmb.2004.03.014] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2003] [Revised: 02/27/2004] [Accepted: 03/02/2004] [Indexed: 11/19/2022]
Abstract
Using DTT(red) as the reducing agent, the kinetics of the reductive unfolding of onconase, a frog ribonuclease, has been examined. An intermediate containing three disulfides, Ir, that is formed rapidly in the reductive pathway, is more resistant to further reduction than the parent molecule, indicating that the remaining disulfides in onconase are less accessible to DTT(red). Disulfide-bond mapping of Ir indicated that it is a single species lacking the (30-75) disulfide bond. The reductive unfolding pattern of onconase is consistent with an analysis of the exposed surface area of the cysteine sulfur atoms in the (30-75) disulfide bond, which reveals that these atoms are about four- and sevenfold, respectively, more exposed than those in the next two maximally exposed disulfides. By contrast, in the reductive unfolding of the homologue, RNase A, there are two intermediates, arising from the reduction of the (40-95) and (65-72) disulfide bonds, which takes place in parallel, and on a much longer time-scale, compared to the initial reduction of onconase; this behavior is consistent with the almost equally exposed surface areas of the cysteine sulfur atoms that form the (40-95) and (65-72) disulfide bonds in RNase A and the fourfold more exposed cysteine sulfur atoms of the (30-75) disulfide bond in onconase. Analysis and in silico mutation of the residues around the (40-95) disulfide bond in RNase A, which is analogous to the (30-75) disulfide bond of onconase, reveal that the side-chain of tyrosine 92 of RNase A, a highly conserved residue among mammalian pancreatic ribonucleases, lies atop the (40-95) disulfide bond, resulting in a shielding of the corresponding sulfur atoms from the solvent; such burial of the (30-75) sulfur atoms is absent from onconase, due to the replacement of Tyr92 by Arg73, which is situated away from the (30-75) disulfide bond and into the solvent, resulting in the large exposed surface-area of the cysteine sulfur atoms forming this bond. Removal of Tyr92 from RNase A resulted in the relatively rapid reduction of the mutant to form a single intermediate (des [40-95] Y92A), i.e. it resulted in an onconase-like reductive unfolding behavior. The reduction of the P93A mutant of RNase A proceeds through a single intermediate, the des [40-95] P93A species, as in onconase. Although mutation of Pro93 to Ala does not increase the exposed surface area of the (40-95) cysteine sulfur atoms, structural analysis of the mutant reveals that there is greater flexibility in the (40-95) disulfide bond compared to the (65-72) disulfide bond that may make the (40-95) disulfide bond much easier to expose, consistent with the reductive unfolding pathway and kinetics of P93A. Mutation of Tyr92 to Phe92 in RNase A has no effect on its reductive unfolding pathway, suggesting that the hydrogen bond between the hydroxyl group of Tyr92 and the carbonyl group of Lys37 has no impact on the local unfolding free energy required to expose the (40-95) disulfide bond. Thus, these data shed light on the differences between the reductive unfolding pathways of the two homologous proteins and provide a structural basis for the origin of this difference.
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Affiliation(s)
- Mahesh Narayan
- Baker Laboratory of Chemistry and Chemical Biology, Cornell University, Ithaca, NY 14853-1301, USA
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Narayan M, Welker E, Wanjalla C, Xu G, Scheraga HA. Shifting the competition between the intramolecular Reshuffling reaction and the direct oxidation reaction during the oxidative folding of kinetically trapped disulfide-insecure intermediates. Biochemistry 2003; 42:10783-9. [PMID: 12962503 DOI: 10.1021/bi030141o] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The oxidative folding pathway(s) of single-domain proteins can be characterized by the existence, stability, and structural nature of the intermediates that populate the regeneration pathway. Structured intermediates can be disulfide-secure in that they are able to protect their existing (native) disulfide bonds from SH/SS reshuffling and reduction reactions, and thereby form the native protein directly, i.e., by oxidation of their exposed (or locally exposable) thiols. Alternatively, they can be disulfide-insecure, usually requiring global unfolding to expose their free thiols. However, such an unfolding event also exposes the existing native disulfide bonds. Thus, the subsequent oxidation reaction to form the native protein in a disulfide-insecure intermediate competes with the intramolecular attack by the thiols of the macromolecule on its own native disulfide bonds, resulting in a large population of intermediates that are reshuffled instead of being oxidized. Under stabilizing conditions, disulfide-insecure species become long-lived kinetically trapped intermediates that slowly and only indirectly convert to the native protein through reshuffling reactions. In this study, trans-[Pt(en)(2)Cl(2)](2+), a strong oxidizing agent which has not traditionally been used in oxidative folding, was applied to shift the competition between reshuffling and oxidation reactions in des [58-110] and des [26-84], two long-lived disulfide-insecure intermediates of RNase A, and oxidize them directly under stable conditions to form the native protein. Such a successful direct conversion of kinetically trapped intermediates to the native molecule by trans-[Pt(en)(2)Cl(2)](2+) may be helpful in facilitating the oxidative folding processes of multi-disulfide-containing proteins in general.
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Affiliation(s)
- Mahesh Narayan
- Baker Laboratory of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853-1301, USA
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