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Schönmehl R, Mendelsohn DH, Winter L, Pabel S, Niedermair T, Evert K, Cheung WH, Wong RMY, Schmitt VH, Keller K, Barsch F, Dietl A, Gummert JF, Schramm R, Sossalla S, Brochhausen C. Comparative Analysis of Mitochondria Surrounding the Intercalated Discs in Heart Diseases-An Ultrastructural Pilot Study. Int J Mol Sci 2024; 25:7644. [PMID: 39062885 PMCID: PMC11277158 DOI: 10.3390/ijms25147644] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2024] [Revised: 06/28/2024] [Accepted: 07/05/2024] [Indexed: 07/28/2024] Open
Abstract
BACKGROUND Mitochondria play a crucial role in adapting to fluctuating energy demands, particularly in various heart diseases. This study investigates mitochondrial morphology near intercalated discs in left ventricular (LV) heart tissues, comparing samples from patients with sinus rhythm (SR), atrial fibrillation (AF), dilated cardiomyopathy (DCM), and ischemic cardiomyopathy (ICM). METHODS Transmission electron microscopy was used to analyze mitochondria within 0-3.5 μm and 3.5-7 μm of intercalated discs in 9 SR, 10 AF, 9 DCM, and 8 ICM patient samples. Parameters included mean size in µm2 and elongation, count, percental mitochondrial area in the measuring frame, and a conglomeration score. RESULTS AF patients exhibited higher counts of small mitochondria in the LV myocardium, resembling SR. DCM and ICM groups had fewer, larger, and often hydropic mitochondria. Accumulation rates and percental mitochondrial area were similar across groups. Significant positive correlations existed between other defects/size and hydropic mitochondria and between count/area and conglomeration score, while negative correlations between count and size/other defects and between hydropic mitochondria and count could be seen as well. CONCLUSION Mitochondrial parameters in the LV myocardium of AF patients were similar to those of SR patients, while DCM and ICM displayed distinct changes, including a decrease in number, an increase in size, and compromised mitochondrial morphology. Further research is needed to fully elucidate the pathophysiological role of mitochondrial morphology in different heart diseases, providing deeper insights into potential therapeutic targets and interventions.
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Affiliation(s)
- Rebecca Schönmehl
- Institute of Pathology, Medical Faculty Mannheim, Heidelberg University, 68167 Mannheim, Germany
| | - Daniel H. Mendelsohn
- Institute of Pathology, Medical Faculty Mannheim, Heidelberg University, 68167 Mannheim, Germany
| | - Lina Winter
- Institute of Pathology, Medical Faculty Mannheim, Heidelberg University, 68167 Mannheim, Germany
| | - Steffen Pabel
- Department of Internal Medicine II, University Medical Center Regensburg, 93053 Regensburg, Germany
| | - Tanja Niedermair
- Institute of Pathology, University of Regensburg, 93053 Regensburg, Germany (K.E.)
- Central Biobank Regensburg, University and University Hospital Regensburg, 93053 Regensburg, Germany
| | - Katja Evert
- Institute of Pathology, University of Regensburg, 93053 Regensburg, Germany (K.E.)
| | - Wing-Hoi Cheung
- Department of Orthopedics and Traumatology, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Ronald Man Yeung Wong
- Department of Orthopedics and Traumatology, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Volker H. Schmitt
- Department of Cardiology, University Medical Centre, Johannes Gutenberg University of Mainz, 55131 Mainz, Germany (K.K.)
- German Center for Cardiovascular Research (DZHK), Partner Site Rhine Main, 55131 Mainz, Germany
| | - Karsten Keller
- Department of Cardiology, University Medical Centre, Johannes Gutenberg University of Mainz, 55131 Mainz, Germany (K.K.)
- Center for Thrombosis and Hemostasis (CTH), University Medical Center Mainz, Johannes Gutenberg-University Mainz, 55131 Mainz, Germany
- Department of Sports Medicine, Medical Clinic VII, University Hospital Heidelberg, 69120 Heidelberg, Germany
| | - Friedrich Barsch
- Medical Center, Faculty of Medicine, Institute for Exercise and Occupational Medicine, University of Freiburg, 79106 Freiburg, Germany
| | - Alexander Dietl
- Department of Internal Medicine II, University Hospital Regensburg, 93053 Regensburg, Germany;
| | - Jan F. Gummert
- Clinic for Thoracic and Cardiovascular Surgery, Heart and Diabetes Center North Rhine-Westphalia, Ruhr University Bochum, 32545 Bad Oeynhausen, Germany
| | - René Schramm
- Clinic for Thoracic and Cardiovascular Surgery, Heart and Diabetes Center North Rhine-Westphalia, Ruhr University Bochum, 32545 Bad Oeynhausen, Germany
| | - Samuel Sossalla
- Department of Internal Medicine II, University Medical Center Regensburg, 93053 Regensburg, Germany
- Departments of Cardiology at Kerckhoff Heart and Lung Center, Bad Nauheim and University of Giessen, 61231 Bad Nauheim, Germany
| | - Christoph Brochhausen
- Institute of Pathology, Medical Faculty Mannheim, Heidelberg University, 68167 Mannheim, Germany
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2
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Heidler J, Cabrera-Orefice A, Wittig I, Heyne E, Tomczak JN, Petersen B, Henze D, Pohjoismäki JLO, Szibor M. Hyperbaric oxygen treatment reveals spatiotemporal OXPHOS plasticity in the porcine heart. PNAS NEXUS 2024; 3:pgae210. [PMID: 38881840 PMCID: PMC11179111 DOI: 10.1093/pnasnexus/pgae210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Accepted: 05/17/2024] [Indexed: 06/18/2024]
Abstract
Cardiomyocytes meet their high ATP demand almost exclusively by oxidative phosphorylation (OXPHOS). Adequate oxygen supply is an essential prerequisite to keep OXPHOS operational. At least two spatially distinct mitochondrial subpopulations facilitate OXPHOS in cardiomyocytes, i.e. subsarcolemmal (SSM) and interfibrillar mitochondria (IFM). Their intracellular localization below the sarcolemma or buried deep between the sarcomeres suggests different oxygen availability. Here, we studied SSM and IFM isolated from piglet hearts and found significantly lower activities of electron transport chain enzymes and F1FO-ATP synthase in IFM, indicative for compromised energy metabolism. To test the contribution of oxygen availability to this outcome, we ventilated piglets under hyperbaric hyperoxic (HBO) conditions for 240 min. HBO treatment raised OXPHOS enzyme activities in IFM to the level of SSM. Complexome profiling analysis revealed that a high proportion of the F1FO-ATP synthase in the IFM was in a disassembled state prior to the HBO treatment. Upon increased oxygen availability, the enzyme was found to be largely assembled, which may account for the observed increase in OXPHOS complex activities. Although HBO also induced transcription of genes involved in mitochondrial biogenesis, a full proteome analysis revealed only minimal alterations, meaning that HBO-mediated tissue remodeling is an unlikely cause for the observed differences in OXPHOS. We conclude that a previously unrecognized oxygen-regulated mechanism endows cardiac OXPHOS with spatiotemporal plasticity that may underlie the enormous metabolic and contractile adaptability of the heart.
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Affiliation(s)
- Juliana Heidler
- Functional Proteomics, Institute of Cardiovascular Physiology, Faculty of Medicine, Goethe University Frankfurt, 60590 Frankfurt am Main, Germany
- Experimental Vascular Surgery, University Clinic of Vascular Surgery, Innsbruck Medical University, 6020 Innsbruck, Austria
| | - Alfredo Cabrera-Orefice
- Functional Proteomics, Institute of Cardiovascular Physiology, Faculty of Medicine, Goethe University Frankfurt, 60590 Frankfurt am Main, Germany
| | - Ilka Wittig
- Functional Proteomics, Institute of Cardiovascular Physiology, Faculty of Medicine, Goethe University Frankfurt, 60590 Frankfurt am Main, Germany
| | - Estelle Heyne
- Department of Cardiothoracic Surgery, Center for Sepsis Control and Care (CSCC), Jena University Hospital, Friedrich Schiller University of Jena, 07747 Jena, Germany
| | - Jan-Niklas Tomczak
- Functional Proteomics, Institute of Cardiovascular Physiology, Faculty of Medicine, Goethe University Frankfurt, 60590 Frankfurt am Main, Germany
| | - Bjoern Petersen
- Institute of Farm Animal Genetics, Friedrich-Loeffler-Institute (FLI), 31535 Mariensee, Germany
| | - Dirk Henze
- Praxis für Anästhesiologie, Dr. Henze & Partner GbR, 06116 Halle (Saale), Germany
| | - Jaakko L O Pohjoismäki
- Department of Environmental and Biological Sciences, University of Eastern Finland, 80101 Joensuu, Finland
| | - Marten Szibor
- Department of Cardiothoracic Surgery, Center for Sepsis Control and Care (CSCC), Jena University Hospital, Friedrich Schiller University of Jena, 07747 Jena, Germany
- Faculty of Medicine and Health Technology, Tampere University, 33014 Tampere, Finland
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3
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Jenkins BC, Neikirk K, Katti P, Claypool SM, Kirabo A, McReynolds MR, Hinton A. Mitochondria in disease: changes in shapes and dynamics. Trends Biochem Sci 2024; 49:346-360. [PMID: 38402097 PMCID: PMC10997448 DOI: 10.1016/j.tibs.2024.01.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Revised: 01/14/2024] [Accepted: 01/26/2024] [Indexed: 02/26/2024]
Abstract
Mitochondrial structure often determines the function of these highly dynamic, multifunctional, eukaryotic organelles, which are essential for maintaining cellular health. The dynamic nature of mitochondria is apparent in descriptions of different mitochondrial shapes [e.g., donuts, megamitochondria (MGs), and nanotunnels] and crista dynamics. This review explores the significance of dynamic alterations in mitochondrial morphology and regulators of mitochondrial and cristae shape. We focus on studies across tissue types and also describe new microscopy techniques for detecting mitochondrial morphologies both in vivo and in vitro that can improve understanding of mitochondrial structure. We highlight the potential therapeutic benefits of regulating mitochondrial morphology and discuss prospective avenues to restore mitochondrial bioenergetics to manage diseases related to mitochondrial dysfunction.
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Affiliation(s)
- Brenita C Jenkins
- Department of Biochemistry and Molecular Biology, The Huck Institute of the Life Sciences, Pennsylvania State University, State College, PA 16801, USA
| | - Kit Neikirk
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232, USA
| | - Prasanna Katti
- National Heart, Lung and Blood Institute, National Institutes of Health, 9000 Rockville Pike, Bethesda, MD 20892, USA
| | - Steven M Claypool
- Department of Physiology, Mitochondrial Phospholipid Research Center, Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Annet Kirabo
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232, USA; Vanderbilt Center for Immunobiology, Vanderbilt University Medical Center, Nashville, TN 37232, USA; Vanderbilt Institute for Infection, Immunology and Inflammation, Vanderbilt University Medical Center, Nashville, TN 37232, USA; Vanderbilt Institute for Global Health, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Melanie R McReynolds
- Department of Biochemistry and Molecular Biology, The Huck Institute of the Life Sciences, Pennsylvania State University, State College, PA 16801, USA.
| | - Antentor Hinton
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232, USA.
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4
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Marshall AG, Neikirk K, Stephens D, Garza-Lopez E, Vue Z, Beasley HK, Janumyan Doe Y, Campbell D, Fears L, Alghanem A, Spencer EC, Scudese E, Owens B, Vang C, Morton DJ, Conley Z, Hinton A. A workshop on mitochondria for students to improve understanding of science and hypothesis forming. ADVANCES IN PHYSIOLOGY EDUCATION 2023; 47:823-830. [PMID: 37650143 PMCID: PMC10854815 DOI: 10.1152/advan.00116.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 08/10/2023] [Accepted: 08/26/2023] [Indexed: 09/01/2023]
Abstract
There remains a clear deficiency in recruiting middle school students in science, technology, engineering, mathematics, and medicine fields, especially for those students entering physiology from underrepresented backgrounds. A large part of this may be arising from a disconnect between how science is typically practiced at a collegiate and K-12 level. Here, we have envisioned mitochondria and their diverse subcellular structures as an involver for middle school students. We present the framework for a workshop that familiarizes students with mitochondria, employing three-dimensional visual-spatial learning and real-time critical thinking and hypothesis forming. This workshop had the goal of familiarizing middle school students with the unique challenges the field currently faces and better understanding the actuality of being a scientist through critical analysis including hypothesis forming. Findings show that middle school students responded positively to the program and felt as though they had a better understanding of mitochondria. Future implications for hands-on programs to involve underrepresented students in science are discussed, as well as potential considerations to adapt it for high school and undergraduate students.NEW & NOTEWORTHY Here we employ a workshop that utilizes blended and tactile learning to teach middle schoolers about mitochondrial structure. By creating an approachable and fun workshop that can be utilized for middle school students, we seek to encourage them to join a career in physiology.
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Affiliation(s)
- Andrea G Marshall
- 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
| | - Dominique Stephens
- 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
| | - Zer Vue
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, United States
| | - Heather K Beasley
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, United States
| | - Yelena Janumyan Doe
- Collaborative for STEM Education and Outreach, Department of Teaching and Learning, Vanderbilt University, Nashville, Tennessee, United States
| | - Desmond Campbell
- Collaborative for STEM Education and Outreach, Department of Teaching and Learning, Vanderbilt University, Nashville, Tennessee, United States
| | - Letimicia Fears
- Collaborative for STEM Education and Outreach, Department of Teaching and Learning, Vanderbilt University, Nashville, Tennessee, United States
| | - Ahmad Alghanem
- King Abdullah International Medical Research Center (KAIMRC), Riyadh, Saudi Arabia
| | - Elsie C Spencer
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, United States
- Teachers College, Columbia University, New York, New York, United States
| | - 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), Rio de Janeiro, Brazil
| | - Beverly Owens
- Department of Chemistry, Cleveland Early College High School, Shelby, North Carolina, United States
| | - Chia Vang
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, United States
- Counseling Department, New Highlands University, Las Vegas, New Mexico, United States
| | - Derrick J Morton
- Kaiser Permanente Bernard J. Tyson School of Medicine, Department of Biomedical Science, Pasadena, California, United States
- Department of Biological Sciences, University of Southern California, Los Angeles, California, United States
| | - Zachary Conley
- Collaborative for STEM Education and Outreach, Department of Teaching and Learning, Vanderbilt University, Nashville, Tennessee, United States
| | - Antentor Hinton
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, United States
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5
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Kinetic Mathematical Modeling of Oxidative Phosphorylation in Cardiomyocyte Mitochondria. Cells 2022; 11:cells11244020. [PMID: 36552784 PMCID: PMC9777548 DOI: 10.3390/cells11244020] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 12/05/2022] [Accepted: 12/08/2022] [Indexed: 12/15/2022] Open
Abstract
Oxidative phosphorylation (OXPHOS) is an oxygen-dependent process that consumes catabolized nutrients to produce adenosine triphosphate (ATP) to drive energy-dependent biological processes such as excitation-contraction coupling in cardiomyocytes. In addition to in vivo and in vitro experiments, in silico models are valuable for investigating the underlying mechanisms of OXPHOS and predicting its consequences in both physiological and pathological conditions. Here, we compare several prominent kinetic models of OXPHOS in cardiomyocytes. We examine how their mathematical expressions were derived, how their parameters were obtained, the conditions of their experimental counterparts, and the predictions they generated. We aim to explore the general landscape of energy production mechanisms in cardiomyocytes for future in silico models.
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6
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Differential remodelling of mitochondrial subpopulations and mitochondrial dysfunction are a feature of early stage diabetes. Sci Rep 2022; 12:978. [PMID: 35046471 PMCID: PMC8770458 DOI: 10.1038/s41598-022-04929-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Accepted: 12/22/2021] [Indexed: 12/28/2022] Open
Abstract
Mitochondrial dysfunction is a feature of type I and type II diabetes, but there is a lack of consistency between reports and links to disease development. We aimed to investigate if mitochondrial structure–function remodelling occurs in the early stages of diabetes by employing a mouse model (GENA348) of Maturity Onset Diabetes in the Young, exhibiting hyperglycemia, but not hyperinsulinemia, with mild left ventricular dysfunction. Employing 3-D electron microscopy (SBF-SEM) we determined that compared to wild-type, WT, the GENA348 subsarcolemma mitochondria (SSM) are ~ 2-fold larger, consistent with up-regulation of fusion proteins Mfn1, Mfn2 and Opa1. Further, in comparison, GENA348 mitochondria are more irregular in shape, have more tubular projections with SSM projections being longer and wider. Mitochondrial density is also increased in the GENA348 myocardium consistent with up-regulation of PGC1-α and stalled mitophagy (down-regulation of PINK1, Parkin and Miro1). GENA348 mitochondria have more irregular cristae arrangements but cristae dimensions and density are similar to WT. GENA348 Complex activity (I, II, IV, V) activity is decreased but the OCR is increased, potentially linked to a shift towards fatty acid oxidation due to impaired glycolysis. These novel data reveal that dysregulated mitochondrial morphology, dynamics and function develop in the early stages of diabetes.
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7
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Isolation and reconstruction of cardiac mitochondria from SBEM images using a deep learning-based method. J Struct Biol 2021; 214:107806. [PMID: 34742833 DOI: 10.1016/j.jsb.2021.107806] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Revised: 10/06/2021] [Accepted: 10/27/2021] [Indexed: 11/23/2022]
Abstract
Mitochondrial morphological defects are a common feature of diseased cardiac myocytes. However, quantitative assessment of mitochondrial morphology is limited by the time-consuming manual segmentation of electron micrograph (EM) images. To advance understanding of the relation between morphological defects and dysfunction, an efficient morphological reconstruction method is desired to enable isolation and reconstruction of mitochondria from EM images. We propose a new method for isolating and reconstructing single mitochondria from serial block-face scanning EM (SBEM) images. CDeep3M, a cloud-based deep learning network for EM images, was used to segment mitochondrial interior volumes and boundaries. Post-processing was performed using both the predicted interior volume and exterior boundary to isolate and reconstruct individual mitochondria. Series of SBEM images from two separate cardiac myocytes were processed. The highest F1-score was 95% using 50 training datasets, greater than that for previously reported automated methods and comparable to manual segmentations. Accuracy of separation of individual mitochondria was 80% on a pixel basis. A total of 2315 mitochondria in the two series of SBEM images were evaluated with a mean volume of 0.78 µm3. The volume distribution was very broad and skewed; the most frequent mitochondria were 0.04-0.06 µm3, but mitochondria larger than 2.0 µm3 accounted for more than 10% of the total number. The average short-axis length was 0.47 µm. Primarily longitudinal mitochondria (0-30 degrees) were dominant (54%). This new automated segmentation and separation method can help quantitate mitochondrial morphology and improve understanding of myocyte structure-function relationships.
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8
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Feng Y, Huang W, Paul C, Liu X, Sadayappan S, Wang Y, Pauklin S. Mitochondrial nucleoid in cardiac homeostasis: bidirectional signaling of mitochondria and nucleus in cardiac diseases. Basic Res Cardiol 2021; 116:49. [PMID: 34392401 PMCID: PMC8364536 DOI: 10.1007/s00395-021-00889-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Accepted: 07/20/2021] [Indexed: 01/11/2023]
Abstract
Metabolic function and energy production in eukaryotic cells are regulated by mitochondria, which have been recognized as the intracellular 'powerhouses' of eukaryotic cells for their regulation of cellular homeostasis. Mitochondrial function is important not only in normal developmental and physiological processes, but also in a variety of human pathologies, including cardiac diseases. An emerging topic in the field of cardiovascular medicine is the implication of mitochondrial nucleoid for metabolic reprogramming. This review describes the linear/3D architecture of the mitochondrial nucleoid (e.g., highly organized protein-DNA structure of nucleoid) and how it is regulated by a variety of factors, such as noncoding RNA and its associated R-loop, for metabolic reprogramming in cardiac diseases. In addition, we highlight many of the presently unsolved questions regarding cardiac metabolism in terms of bidirectional signaling of mitochondrial nucleoid and 3D chromatin structure in the nucleus. In particular, we explore novel techniques to dissect the 3D structure of mitochondrial nucleoid and propose new insights into the mitochondrial retrograde signaling, and how it regulates the nuclear (3D) chromatin structures in mitochondrial diseases.
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Affiliation(s)
- Yuliang Feng
- Botnar Research Centre, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, Old Road, University of Oxford, Oxford, OX3 7LD, UK
| | - Wei Huang
- Department of Pathology and Laboratory Medicine, Regenerative Medicine Research, University of Cincinnati College of Medicine, 231 Albert Sabin Way, CincinnatiCincinnati, OH, 45267-0529, USA
| | - Christian Paul
- Department of Pathology and Laboratory Medicine, Regenerative Medicine Research, University of Cincinnati College of Medicine, 231 Albert Sabin Way, CincinnatiCincinnati, OH, 45267-0529, USA
| | - Xingguo Liu
- Bioland Laboratory (Guangzhou Regenerative Medicine and Health Guangdong Laboratory), CAS Key Laboratory of Regenerative Biology, Joint School of Life Sciences, Hefei Institute of Stem Cell and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, 510530, China
- Guangzhou Regenerative Medicine and Health Guangdong Laboratory, CAS Key Laboratory of Regenerative Biology, Joint School of Life Sciences, Hefei Institute of Stem Cell and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Guangzhou Medical University, Guangzhou, 510530, China
- Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Institute for Stem Cell and Regeneration, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, 510530, China
| | - Sakthivel Sadayappan
- Heart, Lung and Vascular Institute, Division of Cardiovascular Health and Disease, Department of Internal Medicine, University of Cincinnati, Cincinnati, OH, 45267, USA
| | - Yigang Wang
- Department of Pathology and Laboratory Medicine, Regenerative Medicine Research, University of Cincinnati College of Medicine, 231 Albert Sabin Way, CincinnatiCincinnati, OH, 45267-0529, USA.
| | - Siim Pauklin
- Botnar Research Centre, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, Old Road, University of Oxford, Oxford, OX3 7LD, UK.
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9
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Hamilton S, Terentyeva R, Clements RT, Belevych AE, Terentyev D. Sarcoplasmic reticulum-mitochondria communication; implications for cardiac arrhythmia. J Mol Cell Cardiol 2021; 156:105-113. [PMID: 33857485 DOI: 10.1016/j.yjmcc.2021.04.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 03/15/2021] [Accepted: 04/05/2021] [Indexed: 12/11/2022]
Abstract
Sudden cardiac death due to ventricular tachyarrhythmias remains the major cause of mortality in the world. Heart failure, diabetic cardiomyopathy, old age-related cardiac dysfunction and inherited disorders are associated with enhanced propensity to malignant cardiac arrhythmias. Both defective mitochondrial function and abnormal intracellular Ca2+ homeostasis have been established as the key contributing factors in the pathophysiology and arrhythmogenesis in these conditions. This article reviews current advances in understanding of bidirectional control of ryanodine receptor-mediated sarcoplasmic reticulum Ca2+ release and mitochondrial function, and how defects in crosstalk between these two organelles increase arrhythmic risk in cardiac disease.
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Affiliation(s)
- Shanna Hamilton
- Department of Physiology and Cell Biology, Davis Heart and Lung Research Institute, Wexner Medical Center, The Ohio State University, Columbus, OH, United States of America
| | - Radmila Terentyeva
- Department of Physiology and Cell Biology, Davis Heart and Lung Research Institute, Wexner Medical Center, The Ohio State University, Columbus, OH, United States of America
| | - Richard T Clements
- Biomedical & Pharmaceutical Sciences, University of Rhode Island, Kingston, RI, United States of America
| | - Andriy E Belevych
- Department of Physiology and Cell Biology, Davis Heart and Lung Research Institute, Wexner Medical Center, The Ohio State University, Columbus, OH, United States of America
| | - Dmitry Terentyev
- Department of Physiology and Cell Biology, Davis Heart and Lung Research Institute, Wexner Medical Center, The Ohio State University, Columbus, OH, United States of America.
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10
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Torres MJ, McLaughlin KL, Renegar RH, Valsaraj S, Whitehurst KS, Sharaf OM, Sharma UM, Horton JL, Sarathy B, Parks JC, Brault JJ, Fisher-Wellman KH, Neufer PD, Virag JAI. Intracardiac administration of ephrinA1-Fc preserves mitochondrial bioenergetics during acute ischemia/reperfusion injury. Life Sci 2019; 239:117053. [PMID: 31733316 DOI: 10.1016/j.lfs.2019.117053] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Revised: 11/06/2019] [Accepted: 11/08/2019] [Indexed: 12/18/2022]
Abstract
AIMS Intracardiac injection of recombinant EphrinA1-Fc immediately following coronary artery ligation in mice reduces infarct size in both reperfused and non-reperfused myocardium, but the cellular alterations behind this phenomenon remain unknown. MAIN METHODS Herein, 10 wk-old B6129SF2/J male mice were exposed to acute ischemia/reperfusion (30minI/24hrsR) injury immediately followed by intracardiac injection of either EphrinA1-Fc or IgG-Fc. After 24 h of reperfusion, sections of the infarct margin in the left ventricle were imaged via transmission electron microscopy, and mitochondrial function was assessed in both permeabilized fibers and isolated mitochondria, to examine mitochondrial structure, function, and energetics in the early stages of repair. KEY FINDINGS At a structural level, EphrinA1-Fc administration prevented the I/R-induced loss of sarcomere alignment and mitochondrial organization along the Z disks, as well as disorganization of the cristae and loss of inter-mitochondrial junctions. With respect to bioenergetics, loss of respiratory function induced by I/R was prevented by EphrinA1-Fc. Preservation of cardiac bioenergetics was not due to changes in mitochondrial JH2O2 emitting potential, membrane potential, ADP affinity, efficiency of ATP production, or activity of the main dehydrogenase enzymes, suggesting that EphrinA1-Fc indirectly maintains respiratory function via preservation of the mitochondrial network. Moreover, these protective effects were lost in isolated mitochondria, further emphasizing the importance of the intact cardiomyocyte ultrastructure in mitochondrial energetics. SIGNIFICANCE Collectively, these data suggest that intracardiac injection of EphrinA1-Fc protects cardiac function by preserving cardiomyocyte structure and mitochondrial bioenergetics, thus emerging as a potential therapeutic strategy in I/R injury.
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Affiliation(s)
- Maria J Torres
- East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, NC, 27834, USA
| | - Kelsey L McLaughlin
- East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, NC, 27834, USA; Dept of Physiology, Brody School of Medicine, East Carolina University, Greenville, NC, 27834, USA
| | - Randall H Renegar
- Dept of Anatomy and Cell Biology, Brody School of Medicine, East Carolina University, Greenville, NC, 27834, USA
| | - Smrithi Valsaraj
- Dept of Physiology, Brody School of Medicine, East Carolina University, Greenville, NC, 27834, USA
| | - K'Shylah S Whitehurst
- Dept of Physiology, Brody School of Medicine, East Carolina University, Greenville, NC, 27834, USA
| | - Omar M Sharaf
- Dept of Physiology, Brody School of Medicine, East Carolina University, Greenville, NC, 27834, USA
| | - Uma M Sharma
- Dept of Physiology, Brody School of Medicine, East Carolina University, Greenville, NC, 27834, USA
| | - Julie L Horton
- East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, NC, 27834, USA; Dept of Physiology, Brody School of Medicine, East Carolina University, Greenville, NC, 27834, USA
| | - Brinda Sarathy
- Dept of Physiology, Brody School of Medicine, East Carolina University, Greenville, NC, 27834, USA
| | - Justin C Parks
- Dept of Physiology, Brody School of Medicine, East Carolina University, Greenville, NC, 27834, USA
| | - Jeffrey J Brault
- Dept of Physiology, Brody School of Medicine, East Carolina University, Greenville, NC, 27834, USA; Dept of Kinesiology, College of Health and Human Performance, East Carolina University, Greenville, NC, 27834, USA
| | - Kelsey H Fisher-Wellman
- East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, NC, 27834, USA; Dept of Physiology, Brody School of Medicine, East Carolina University, Greenville, NC, 27834, USA
| | - P Darrell Neufer
- East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, NC, 27834, USA; Dept of Physiology, Brody School of Medicine, East Carolina University, Greenville, NC, 27834, USA
| | - Jitka A I Virag
- Dept of Physiology, Brody School of Medicine, East Carolina University, Greenville, NC, 27834, USA.
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11
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Cosi FG, Giese W, Neubert W, Luther S, Chamakuri N, Parlitz U, Falcke M. Multiscale Modeling of Dyadic Structure-Function Relation in Ventricular Cardiac Myocytes. Biophys J 2019; 117:2409-2419. [PMID: 31635789 PMCID: PMC6990380 DOI: 10.1016/j.bpj.2019.09.023] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 09/11/2019] [Accepted: 09/16/2019] [Indexed: 01/20/2023] Open
Abstract
Cardiovascular disease is often related to defects of subcellular components in cardiac myocytes, specifically in the dyadic cleft, which include changes in cleft geometry and channel placement. Modeling of these pathological changes requires both spatially resolved cleft as well as whole cell level descriptions. We use a multiscale model to create dyadic structure-function relationships to explore the impact of molecular changes on whole cell electrophysiology and calcium cycling. This multiscale model incorporates stochastic simulation of individual L-type calcium channels and ryanodine receptor channels, spatially detailed concentration dynamics in dyadic clefts, rabbit membrane potential dynamics, and a system of partial differential equations for myoplasmic and lumenal free Ca2+ and Ca2+-binding molecules in the bulk of the cell. We found action potential duration, systolic, and diastolic [Ca2+] to respond most sensitively to changes in L-type calcium channel current. The ryanodine receptor channel cluster structure inside dyadic clefts was found to affect all biomarkers investigated. The shape of clusters observed in experiments by Jayasinghe et al. and channel density within the cluster (characterized by mean occupancy) showed the strongest correlation to the effects on biomarkers.
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Affiliation(s)
- Filippo G Cosi
- Max Planck Institute for Dynamics and Self-Organization, Göttingen, Germany; Georg-August-Universität Göttingen, Institute for the Dynamics of Complex Systems, Göttingen, Germany; DZHK (German Center for Cardiovascular Research), Partner Site Göttingen, Göttingen, Germany
| | - Wolfgang Giese
- Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Wilhelm Neubert
- Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Stefan Luther
- Max Planck Institute for Dynamics and Self-Organization, Göttingen, Germany; Georg-August-Universität Göttingen, Institute for the Dynamics of Complex Systems, Göttingen, Germany; DZHK (German Center for Cardiovascular Research), Partner Site Göttingen, Göttingen, Germany
| | - Nagaiah Chamakuri
- Institute of Applied Mathematics, University of Hohenheim, Stuttgart, Germany
| | - Ulrich Parlitz
- Max Planck Institute for Dynamics and Self-Organization, Göttingen, Germany; Georg-August-Universität Göttingen, Institute for the Dynamics of Complex Systems, Göttingen, Germany; DZHK (German Center for Cardiovascular Research), Partner Site Göttingen, Göttingen, Germany
| | - Martin Falcke
- Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany; DZHK (German Center for Cardiovascular Research), Partner Site Berlin, Berlin, Germany; Department of Physics, Humboldt University Berlin, Germany.
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12
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Ghosh S, Tran K, Delbridge LMD, Hickey AJR, Hanssen E, Crampin EJ, Rajagopal V. Insights on the impact of mitochondrial organisation on bioenergetics in high-resolution computational models of cardiac cell architecture. PLoS Comput Biol 2018; 14:e1006640. [PMID: 30517098 PMCID: PMC6296675 DOI: 10.1371/journal.pcbi.1006640] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Revised: 12/17/2018] [Accepted: 11/13/2018] [Indexed: 01/05/2023] Open
Abstract
Recent electron microscopy data have revealed that cardiac mitochondria are not arranged in crystalline columns but are organised with several mitochondria aggregated into columns of varying sizes spanning the cell cross-section. This raises the question—how does the mitochondrial arrangement affect the metabolite distributions within cardiomyocytes and what is its impact on force dynamics? Here, we address this question by employing finite element modeling of cardiac bioenergetics on computational meshes derived from electron microscope images. Our results indicate that heterogeneous mitochondrial distributions can lead to significant spatial variation across the cell in concentrations of inorganic phosphate, creatine (Cr) and creatine phosphate (PCr). However, our model predicts that sufficient activity of the creatine kinase (CK) system, coupled with rapid diffusion of Cr and PCr, maintains near uniform ATP and ADP ratios across the cell cross sections. This homogenous distribution of ATP and ADP should also evenly distribute force production and twitch duration with contraction. These results suggest that the PCr shuttle and associated enzymatic reactions act to maintain uniform force dynamics in the cell despite the heterogeneous mitochondrial organization. However, our model also predicts that under hypoxia activity of mitochondrial CK enzymes and diffusion of high-energy phosphate compounds may be insufficient to sustain uniform ATP/ADP distribution and hence force generation. Mammalian cardiomyocytes contain a high volume of mitochondria, which maintains the continuous and bulk supply of ATP to sustain normal heart function. Previously, cardiac mitochondria were understood to be distributed in a regular, crystalline pattern, which facilitated a steady supply of ATP at different workloads. Using electron microscopy images of cell cross sections, we recently found that they are not regularly distributed inside cardiomyocytes. We created new spatially accurate computational models of cardiac cell bioenergetics and tested whether this heterogeneous distribution of mitochondria causes non-uniform energy supply and contractile force production in the cardiomyocyte. We found that ATP and ADP concentrations remain uniform throughout the cell because of the activity of creatine kinase (CK) enzymes that convert ATP produced in the mitochondria into creatine phosphate. Creatine phosphate rapidly diffuses to the myofibril region where it can be converted back to ATP for the contraction cycle in a timely manner. This mechanism is called the phosphocreatine shuttle (PCr shuttle). The PCr shuttle ensures that different areas of the cell produce the same amount of force regardless of the mitochondrial distribution. However, our model also shows that when the cellular oxygen supply is limited—as can be the case in conditions such as heart failure—the PCr shuttle cannot maintain uniform ATP and ADP concentrations across the cell. This causes a non-uniform acto-myosin force distribution and non-uniform twitch duration across the cell cross section. Our study suggests that mechanisms other than the PCr shuttle may be necessary to maintain uniform supply of ATP in a hypoxic environment.
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Affiliation(s)
- Shouryadipta Ghosh
- Cell Structure and Mechanobiology Group, Dept. of Biomedical Engineering, Melbourne School of Engineering, University of Melbourne, Melbourne, Australia
- Systems Biology Laboratory, School of Mathematics and Statistics, and Melbourne School of Engineering, University of Melbourne, Melbourne, Australia
| | - Kenneth Tran
- Auckland Bioengineering Institute, University of Auckland, Auckland New Zealand
| | | | | | - Eric Hanssen
- Advanced Microscopy Facility, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Melbourne, Australia
| | - Edmund J. Crampin
- Systems Biology Laboratory, School of Mathematics and Statistics, and Melbourne School of Engineering, University of Melbourne, Melbourne, Australia
- ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, University of Melbourne, Melbourne, Australia
| | - Vijay Rajagopal
- Cell Structure and Mechanobiology Group, Dept. of Biomedical Engineering, Melbourne School of Engineering, University of Melbourne, Melbourne, Australia
- * E-mail:
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13
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Daghistani HM, Rajab BS, Kitmitto A. Three-dimensional electron microscopy techniques for unravelling mitochondrial dysfunction in heart failure and identification of new pharmacological targets. Br J Pharmacol 2018; 176:4340-4359. [PMID: 30225980 PMCID: PMC6887664 DOI: 10.1111/bph.14499] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Revised: 07/30/2018] [Accepted: 08/18/2018] [Indexed: 12/23/2022] Open
Abstract
A hallmark of heart failure is mitochondrial dysfunction leading to a bioenergetics imbalance in the myocardium. Consequently, there is much interest in targeting mitochondrial abnormalities to attenuate the pathogenesis of heart failure. This review discusses (i) how electron microscopy (EM) techniques have been fundamental for the current understanding of mitochondrial structure–function, (ii) the paradigm shift in resolutions now achievable by 3‐D EM techniques due to the introduction of direct detection devices and phase plate technology, and (iii) the application of EM for unravelling mitochondrial pathological remodelling in heart failure. We further consider the tremendous potential of multi‐scale EM techniques for the development of therapeutics, structure‐based ligand design and for delineating how a drug elicits nanostructural effects at the molecular, organelle and cellular levels. In conclusion, 3‐D EM techniques have entered a new era of structural biology and are poised to play a pivotal role in discovering new therapies targeting mitochondria for treating heart failure. Linked Articles This article is part of a themed section on Mitochondrial Pharmacology: Featured Mechanisms and Approaches for Therapy Translation. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v176.22/issuetoc
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Affiliation(s)
- Hussam M Daghistani
- Division of Cardiovascular Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, Manchester, UK
| | - Bodour S Rajab
- Division of Cardiovascular Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, Manchester, UK
| | - Ashraf Kitmitto
- Division of Cardiovascular Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, Manchester, UK
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14
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Shepherd DL, Hathaway QA, Pinti MV, Nichols CE, Durr AJ, Sreekumar S, Hughes KM, Stine SM, Martinez I, Hollander JM. Exploring the mitochondrial microRNA import pathway through Polynucleotide Phosphorylase (PNPase). J Mol Cell Cardiol 2017; 110:15-25. [PMID: 28709769 PMCID: PMC5854179 DOI: 10.1016/j.yjmcc.2017.06.012] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Revised: 06/20/2017] [Accepted: 06/27/2017] [Indexed: 01/01/2023]
Abstract
Cardiovascular disease is the primary cause of mortality for individuals with type 2 diabetes mellitus. During the diabetic condition, cardiovascular dysfunction can be partially attributed to molecular changes in the tissue, including alterations in microRNA (miRNA) interactions. MiRNAs have been reported in the mitochondrion and their presence may influence cellular bioenergetics, creating decrements in functional capacity. In this study, we examined the roles of Argonaute 2 (Ago2), a protein associated with cytosolic and mitochondrial miRNAs, and Polynucleotide Phosphorylase (PNPase), a protein found in the inner membrane space of the mitochondrion, to determine their role in mitochondrial miRNA import. In cardiac tissue from human and mouse models of type 2 diabetes mellitus, Ago2 protein levels were unchanged while PNPase protein expression levels were increased; also, there was an increase in the association between both proteins in the diabetic state. MiRNA-378 was found to be significantly increased in db/db mice, leading to decrements in ATP6 levels and ATP synthase activity, which was also exhibited when overexpressing PNPase in HL-1 cardiomyocytes and in HL-1 cells with stable miRNA-378 overexpression (HL-1-378). To assess potential therapeutic interventions, flow cytometry evaluated the capacity for targeting miRNA-378 species in mitochondria through antimiR treatment, revealing miRNA-378 level-dependent inhibition. Our study establishes PNPase as a contributor to mitochondrial miRNA import through the transport of miRNA-378, which may regulate bioenergetics during type 2 diabetes mellitus. Further, our data provide evidence that manipulation of PNPase levels may enhance the delivery of antimiR therapeutics to mitochondria in physiological and pathological conditions.
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Affiliation(s)
- Danielle L Shepherd
- Division of Exercise Physiology, West Virginia University School of Medicine, Morgantown, WV 26506, United States; Mitochondria, Metabolism & Bioenergetics Working Group, West Virginia University School of Medicine, Morgantown, WV 26506, United States
| | - Quincy A Hathaway
- Division of Exercise Physiology, West Virginia University School of Medicine, Morgantown, WV 26506, United States; Mitochondria, Metabolism & Bioenergetics Working Group, West Virginia University School of Medicine, Morgantown, WV 26506, United States
| | - Mark V Pinti
- Mitochondria, Metabolism & Bioenergetics Working Group, West Virginia University School of Medicine, Morgantown, WV 26506, United States
| | - Cody E Nichols
- Division of Exercise Physiology, West Virginia University School of Medicine, Morgantown, WV 26506, United States
| | - Andrya J Durr
- Division of Exercise Physiology, West Virginia University School of Medicine, Morgantown, WV 26506, United States; Mitochondria, Metabolism & Bioenergetics Working Group, West Virginia University School of Medicine, Morgantown, WV 26506, United States
| | - Shruthi Sreekumar
- Division of Exercise Physiology, West Virginia University School of Medicine, Morgantown, WV 26506, United States
| | - Kristen M Hughes
- Division of Exercise Physiology, West Virginia University School of Medicine, Morgantown, WV 26506, United States
| | - Seth M Stine
- Division of Exercise Physiology, West Virginia University School of Medicine, Morgantown, WV 26506, United States
| | - Ivan Martinez
- Cancer Cell Biology, West Virginia University School of Medicine, Morgantown, WV 26506, United States
| | - John M Hollander
- Division of Exercise Physiology, West Virginia University School of Medicine, Morgantown, WV 26506, United States; Mitochondria, Metabolism & Bioenergetics Working Group, West Virginia University School of Medicine, Morgantown, WV 26506, United States.
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15
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Sivakumar A, Subbiah R, Balakrishnan R, Rajendhran J. Cardiac mitochondrial dynamics: miR-mediated regulation during cardiac injury. J Mol Cell Cardiol 2017; 110:26-34. [PMID: 28705612 DOI: 10.1016/j.yjmcc.2017.07.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Revised: 07/06/2017] [Accepted: 07/07/2017] [Indexed: 12/20/2022]
Abstract
Mitochondrial integrity is indispensable for cardiac health. With the advent of modern imaging technologies, mitochondrial motility and dynamics within the cell are extensively studied. Terminally differentiated and well-structured cardiomyocytes depict little mitochondrial division and fusion, questioning the contribution of mitochondrial fusion proteins (Mitofusin 1/2 and Optic Atrophy 1 protein) and fission factors (Dynamin-like protein 1 and mitochondrial fission 1 protein) in cardiomyocyte homeostasis. Emerging evidences suggest that alterations in mitochondrial morphology from globular, elongated network to punctate fragmented disconnected structures are a pathological response to ensuing cardiac stress and cardiomyocyte cell death, bringing forth the following question, "what maintains this balance between fusion and fission?" The answer hinges upon the classical "junk" DNA: microRNAs, the endogenous non-coding RNAs. Because of their essential role in numerous signaling pathways, microRNAs are considered to play major roles in the pathogenesis of various diseases. Mitochondria are not exempted from microRNA-mediated regulation. This review defines the importance of mitochondrial structural integrity and the microRNA-mitochondrial dynamics tandem, an imminent dimension of the cardiac homeostasis network. Elucidating their coordinated interaction could spur RNA-based therapeutics for resuscitating functional mitochondrial population during cardiovascular disorders.
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Affiliation(s)
- Anusha Sivakumar
- Cardiac Hypertrophy Laboratory, Department of Molecular Biology, School of Biological Sciences, Madurai Kamaraj University, Madurai 625 021, Tamilnadu, India
| | - Ramasamy Subbiah
- Cardiac Hypertrophy Laboratory, Department of Molecular Biology, School of Biological Sciences, Madurai Kamaraj University, Madurai 625 021, Tamilnadu, India.
| | - Rekha Balakrishnan
- Cardiac Hypertrophy Laboratory, Department of Molecular Biology, School of Biological Sciences, Madurai Kamaraj University, Madurai 625 021, Tamilnadu, India
| | - Jeyaprakash Rajendhran
- Department of Genetics, School of Biological Sciences, Madurai Kamaraj University, Madurai 625 021, Tamil Nadu, India
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16
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Mitochondrial Heterogeneity: Evaluating Mitochondrial Subpopulation Dynamics in Stem Cells. Stem Cells Int 2017; 2017:7068567. [PMID: 28757879 PMCID: PMC5516713 DOI: 10.1155/2017/7068567] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Accepted: 05/03/2017] [Indexed: 01/29/2023] Open
Abstract
Although traditionally viewed as the “powerhouse” of the cell, an accruing body of evidence in the rapidly growing field of mitochondrial biology supports additional roles of mitochondria as key participants in a multitude of cellular functions. While it has been well established that mitochondria in different tissues have distinctive ultrastructural features consistent with differential bioenergetic demands, recent and emerging technical advances in flow cytometry, imaging, and “-omics”-based bioinformatics have only just begun to explore the complex and divergent properties of mitochondria within tissues and cell types. Moreover, contemporary studies evaluating the role of mitochondria in pluripotent stem cells, cellular reprogramming, and differentiation point to a potential importance of mitochondrial subpopulations and heterogeneity in the field of stem cell biology. This review assesses the current literature regarding mitochondrial subpopulations within cell and tissue types and evaluates the current understanding of how mitochondrial diversity and heterogeneity might impact cell fate specification in pluripotent stem cells.
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