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Knockout of zebrafish desmin genes does not cause skeletal muscle degeneration but alters calcium flux. Sci Rep 2021; 11:7505. [PMID: 33820917 PMCID: PMC8021586 DOI: 10.1038/s41598-021-86974-w] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2020] [Accepted: 03/23/2021] [Indexed: 01/01/2023] Open
Abstract
Desmin is a muscle-specific intermediate filament protein that has fundamental role in muscle structure and force transmission. Whereas human desmin protein is encoded by a single gene, two desmin paralogs (desma and desmb) exist in zebrafish. Desma and desmb show differential spatiotemporal expression during zebrafish embryonic and larval development, being similarly expressed in skeletal muscle until hatching, after which expression of desmb shifts to gut smooth muscle. We generated knockout (KO) mutant lines carrying loss-of-function mutations for each gene by using CRISPR/Cas9. Mutants are viable and fertile, and lack obvious skeletal muscle, heart or intestinal defects. In contrast to morphants, knockout of each gene did not cause any overt muscular phenotype, but did alter calcium flux in myofibres. These results point to a possible compensation mechanism in these mutant lines generated by targeting nonsense mutations to the first coding exon.
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52
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Alevriadou BR, Patel A, Noble M, Ghosh S, Gohil VM, Stathopulos PB, Madesh M. Molecular nature and physiological role of the mitochondrial calcium uniporter channel. Am J Physiol Cell Physiol 2021; 320:C465-C482. [PMID: 33296287 PMCID: PMC8260355 DOI: 10.1152/ajpcell.00502.2020] [Citation(s) in RCA: 51] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Revised: 11/23/2020] [Accepted: 11/23/2020] [Indexed: 02/07/2023]
Abstract
Calcium (Ca2+) signaling is critical for cell function and cell survival. Mitochondria play a major role in regulating the intracellular Ca2+ concentration ([Ca2+]i). Mitochondrial Ca2+ uptake is an important determinant of cell fate and governs respiration, mitophagy/autophagy, and the mitochondrial pathway of apoptosis. Mitochondrial Ca2+ uptake occurs via the mitochondrial Ca2+ uniporter (MCU) complex. This review summarizes the present knowledge on the function of MCU complex, regulation of MCU channel, and the role of MCU in Ca2+ homeostasis and human disease pathogenesis. The channel core consists of four MCU subunits and essential MCU regulators (EMRE). Regulatory proteins that interact with them include mitochondrial Ca2+ uptake 1/2 (MICU1/2), MCU dominant-negative β-subunit (MCUb), MCU regulator 1 (MCUR1), and solute carrier 25A23 (SLC25A23). In addition to these proteins, cardiolipin, a mitochondrial membrane-specific phospholipid, has been shown to interact with the channel core. The dynamic interplay between the core and regulatory proteins modulates MCU channel activity after sensing local changes in [Ca2+]i, reactive oxygen species, and other environmental factors. Here, we highlight the structural details of the human MCU heteromeric assemblies and their known roles in regulating mitochondrial Ca2+ homeostasis. MCU dysfunction has been shown to alter mitochondrial Ca2+ dynamics, in turn eliciting cell apoptosis. Changes in mitochondrial Ca2+ uptake have been implicated in pathological conditions affecting multiple organs, including the heart, skeletal muscle, and brain. However, our structural and functional knowledge of this vital protein complex remains incomplete, and understanding the precise role for MCU-mediated mitochondrial Ca2+ signaling in disease requires further research efforts.
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Affiliation(s)
- B Rita Alevriadou
- Department of Biomedical Engineering, Jacobs School of Medicine and Biomedical Sciences and School of Engineering and Applied Sciences, University at Buffalo-State University of New York, Buffalo, New York
| | - Akshar Patel
- Department of Biomedical Engineering, Jacobs School of Medicine and Biomedical Sciences and School of Engineering and Applied Sciences, University at Buffalo-State University of New York, Buffalo, New York
| | - Megan Noble
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada
| | - Sagnika Ghosh
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas
| | - Vishal M Gohil
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas
| | - Peter B Stathopulos
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada
| | - Muniswamy Madesh
- Department of Medicine/Cardiology Division, Center for Precision Medicine, University of Texas Health San Antonio, San Antonio, Texas
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Di Marco G, Vallese F, Jourde B, Bergsdorf C, Sturlese M, De Mario A, Techer-Etienne V, Haasen D, Oberhauser B, Schleeger S, Minetti G, Moro S, Rizzuto R, De Stefani D, Fornaro M, Mammucari C. A High-Throughput Screening Identifies MICU1 Targeting Compounds. Cell Rep 2021; 30:2321-2331.e6. [PMID: 32075766 PMCID: PMC7034061 DOI: 10.1016/j.celrep.2020.01.081] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Revised: 01/08/2020] [Accepted: 01/22/2020] [Indexed: 01/01/2023] Open
Abstract
Mitochondrial Ca2+ uptake depends on the mitochondrial calcium uniporter (MCU) complex, a highly selective channel of the inner mitochondrial membrane (IMM). Here, we screen a library of 44,000 non-proprietary compounds for their ability to modulate mitochondrial Ca2+ uptake. Two of them, named MCU-i4 and MCU-i11, are confirmed to reliably decrease mitochondrial Ca2+ influx. Docking simulations reveal that these molecules directly bind a specific cleft in MICU1, a key element of the MCU complex that controls channel gating. Accordingly, in MICU1-silenced or deleted cells, the inhibitory effect of the two compounds is lost. Moreover, MCU-i4 and MCU-i11 fail to inhibit mitochondrial Ca2+ uptake in cells expressing a MICU1 mutated in the critical amino acids that forge the predicted binding cleft. Finally, these compounds are tested ex vivo, revealing a primary role for mitochondrial Ca2+ uptake in muscle growth. Overall, MCU-i4 and MCU-i11 represent leading molecules for the development of MICU1-targeting drugs. An HTS identifies MCU-i4 and MCU-i11 as negative modulators of the MCU MCU-i4 and MCU-i11 bind MICU1 MICU1 is required for the activity of MCU-i4 and MCU-i11 MCU-i4 and MCU-i11 impair muscle cell growth
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Affiliation(s)
- Giulia Di Marco
- Department of Biomedical Sciences, University of Padua, 35131 Padua, Italy
| | - Francesca Vallese
- Department of Biomedical Sciences, University of Padua, 35131 Padua, Italy
| | - Benjamin Jourde
- Novartis Institutes for Biomedical Research, Novartis Campus, 4056 Basel, Switzerland
| | - Christian Bergsdorf
- Novartis Institutes for Biomedical Research, Novartis Campus, 4056 Basel, Switzerland
| | - Mattia Sturlese
- Molecular Modeling Section, Department of Pharmaceutical and Pharmacological Sciences, University of Padua, 35131 Padua, Italy
| | - Agnese De Mario
- Department of Biomedical Sciences, University of Padua, 35131 Padua, Italy
| | | | - Dorothea Haasen
- Novartis Institutes for Biomedical Research, Novartis Campus, 4056 Basel, Switzerland
| | - Berndt Oberhauser
- Novartis Institutes for Biomedical Research, Novartis Campus, 4056 Basel, Switzerland
| | - Simone Schleeger
- Novartis Institutes for Biomedical Research, Novartis Campus, 4056 Basel, Switzerland
| | - Giulia Minetti
- Novartis Institutes for Biomedical Research, Novartis Campus, 4056 Basel, Switzerland
| | - Stefano Moro
- Molecular Modeling Section, Department of Pharmaceutical and Pharmacological Sciences, University of Padua, 35131 Padua, Italy
| | - Rosario Rizzuto
- Department of Biomedical Sciences, University of Padua, 35131 Padua, Italy
| | - Diego De Stefani
- Department of Biomedical Sciences, University of Padua, 35131 Padua, Italy
| | - Mara Fornaro
- Novartis Institutes for Biomedical Research, Novartis Campus, 4056 Basel, Switzerland.
| | - Cristina Mammucari
- Department of Biomedical Sciences, University of Padua, 35131 Padua, Italy.
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54
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Tanwar J, Singh JB, Motiani RK. Molecular machinery regulating mitochondrial calcium levels: The nuts and bolts of mitochondrial calcium dynamics. Mitochondrion 2021; 57:9-22. [PMID: 33316420 PMCID: PMC7610953 DOI: 10.1016/j.mito.2020.12.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2020] [Revised: 11/18/2020] [Accepted: 12/03/2020] [Indexed: 02/06/2023]
Abstract
Mitochondria play vital role in regulating the cellular energetics and metabolism. Further, it is a signaling hub for cell survival and apoptotic pathways. One of the key determinants that calibrate both cellular energetics and survival functions is mitochondrial calcium (Ca2+) dynamics. Mitochondrial Ca2+ regulates three Ca2+-sensitive dehydrogenase enzymes involved in tricarboxylic acid cycle (TCA) cycle thereby directly controlling ATP synthesis. On the other hand, excessive Ca2+ concentration within the mitochondrial matrix elevates mitochondrial reactive oxygen species (mROS) levels and causes mitochondrial membrane depolarization. This leads to opening of the mitochondrial permeability transition pore (mPTP) and release of cytochrome c into cytosol eventually triggering apoptosis. Therefore, it is critical for cell to maintain mitochondrial Ca2+ concentration. Since cells can neither synthesize nor metabolize Ca2+, it is the dynamic interplay of Ca2+ handling proteins involved in mitochondrial Ca2+ influx and efflux that take the center stage. In this review we would discuss the key molecular machinery regulating mitochondrial Ca2+ concentration. We would focus on the channel complex involved in bringing Ca2+ into mitochondrial matrix i.e. Mitochondrial Ca2+ Uniporter (MCU) and its key regulators Mitochondrial Ca2+ Uptake proteins (MICU1, 2 and 3), MCU regulatory subunit b (MCUb), Essential MCU Regulator (EMRE) and Mitochondrial Ca2+ Uniporter Regulator 1 (MCUR1). Further, we would deliberate on major mitochondrial Ca2+ efflux proteins i.e. Mitochondrial Na+/Ca2+/Li+ exchanger (NCLX) and Leucine zipper EF hand-containing transmembrane1 (Letm1). Moreover, we would highlight the physiological functions of these proteins and discuss their relevance in human pathophysiology. Finally, we would highlight key outstanding questions in the field.
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Affiliation(s)
- Jyoti Tanwar
- CSIR-Institute of Genomics and Integrative Biology (IGIB), New Delhi 10025, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Jaya Bharti Singh
- Laboratory of Calciomics and Systemic Pathophysiology (LCSP), Regional Centre for Biotechnology (RCB), Faridabad, Delhi-NCR, India
| | - Rajender K Motiani
- Laboratory of Calciomics and Systemic Pathophysiology (LCSP), Regional Centre for Biotechnology (RCB), Faridabad, Delhi-NCR, India.
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55
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Horn A, Raavicharla S, Shah S, Cox D, Jaiswal JK. Mitochondrial fragmentation enables localized signaling required for cell repair. J Cell Biol 2021; 219:151605. [PMID: 32236517 PMCID: PMC7199862 DOI: 10.1083/jcb.201909154] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Revised: 02/05/2020] [Accepted: 03/09/2020] [Indexed: 01/08/2023] Open
Abstract
Plasma membrane injury can cause lethal influx of calcium, but cells survive by mounting a polarized repair response targeted to the wound site. Mitochondrial signaling within seconds after injury enables this response. However, as mitochondria are distributed throughout the cell in an interconnected network, it is unclear how they generate a spatially restricted signal to repair the plasma membrane wound. Here we show that calcium influx and Drp1-mediated, rapid mitochondrial fission at the injury site help polarize the repair response. Fission of injury-proximal mitochondria allows for greater amplitude and duration of calcium increase in these mitochondria, allowing them to generate local redox signaling required for plasma membrane repair. Drp1 knockout cells and patient cells lacking the Drp1 adaptor protein MiD49 fail to undergo injury-triggered mitochondrial fission, preventing polarized mitochondrial calcium increase and plasma membrane repair. Although mitochondrial fission is considered to be an indicator of cell damage and death, our findings identify that mitochondrial fission generates localized signaling required for cell survival.
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Affiliation(s)
- Adam Horn
- Children's National Health System, Center for Genetic Medicine Research, Washington, DC
| | - Shreya Raavicharla
- Children's National Health System, Center for Genetic Medicine Research, Washington, DC
| | - Sonna Shah
- Children's National Health System, Center for Genetic Medicine Research, Washington, DC
| | - Dan Cox
- John Walton Muscular Dystrophy Research Centre, Newcastle University and Newcastle Hospitals National Health Service Foundation Trust, Newcastle upon Tyne, UK
| | - Jyoti K Jaiswal
- Children's National Health System, Center for Genetic Medicine Research, Washington, DC.,Department of Genomics and Precision Medicine, George Washington University School of Medicine and Health Sciences, Washington, DC
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56
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Abstract
Mitochondria are responsible for ATP production but are also known as regulators of cell death, and mitochondrial matrix Ca2+ is a key modulator of both ATP production and cell death. Although mitochondrial Ca2+ uptake and efflux have been studied for over 50 years, it is only in the past decade that the proteins responsible for mitochondrial Ca2+ uptake and efflux have been identified. The identification of the mitochondrial Ca2+ uniporter (MCU) led to an explosion of studies identifying regulators of the MCU. The levels of these regulators vary in a tissue- and disease-specific manner, providing new insight into how mitochondrial Ca2+ is regulated. This review focuses on the proteins responsible for mitochondrial transport and what we have learned from mouse studies with genetic alterations in these proteins.
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Affiliation(s)
- Elizabeth Murphy
- Cardiovascular Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892, USA;
| | - Charles Steenbergen
- Department of Pathology, Johns Hopkins Medicine, Baltimore, Maryland 21287, USA
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57
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Boyman L, Greiser M, Lederer WJ. Calcium influx through the mitochondrial calcium uniporter holocomplex, MCU cx. J Mol Cell Cardiol 2021; 151:145-154. [PMID: 33147447 PMCID: PMC7880866 DOI: 10.1016/j.yjmcc.2020.10.015] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/25/2020] [Revised: 10/20/2020] [Accepted: 10/28/2020] [Indexed: 12/11/2022]
Abstract
Ca2+ flux into the mitochondrial matrix through the MCU holocomplex (MCUcx) has recently been measured quantitatively and with milliseconds resolution for the first time under physiological conditions in both heart and skeletal muscle. Additionally, the dynamic levels of Ca2+ in the mitochondrial matrix ([Ca2+]m) of cardiomyocytes were measured as it was controlled by the balance between influx of Ca2+ into the mitochondrial matrix through MCUcx and efflux through the mitochondrial Na+ / Ca2+ exchanger (NCLX). Under these conditions [Ca2+]m was shown to regulate ATP production by the mitochondria at only a few critical sites. Additional functions attributed to [Ca2+]m continue to be reported in the literature. Here we review the new findings attributed to MCUcx function and provide a framework for understanding and investigating mitochondrial Ca2+ influx features, many of which remain controversial. The properties and functions of the MCUcx subunits that constitute the holocomplex are challenging to tease apart. Such distinct subunits include EMRE, MCUR1, MICUx (i.e. MICU1, MICU2, MICU3), and the pore-forming subunits (MCUpore). Currently, the specific set of functions of each subunit remains non-quantitative and controversial. The more contentious issues are discussed in the context of the newly measured native MCUcx Ca2+ flux from heart and skeletal muscle. These MCUcx Ca2+ flux measurements have been shown to be a highly-regulated, tissue-specific with femto-Siemens Ca2+ conductances and with distinct extramitochondrial Ca2+ ([Ca2+]i) dependencies. These data from cardiac and skeletal muscle mitochondria have been examined quantitatively for their threshold [Ca2+]i levels and for hypothesized gatekeeping function and are discussed in the context of model cell (e.g. HeLa, MEF, HEK293, COS7 cells) measurements. Our new findings on MCUcx dependent matrix [Ca2+]m signaling provide a quantitative basis for on-going and new investigations of the roles of MCUcx in cardiac function ranging from metabolic fuel selection, capillary blood-flow control and the pathological activation of the mitochondrial permeability transition pore (mPTP). Additionally, this review presents the use of advanced new methods that can be readily adapted by any investigator to enable them to carry out quantitative Ca2+ measurements in mitochondria while controlling the inner mitochondrial membrane potential, ΔΨm.
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Affiliation(s)
- Liron Boyman
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD, USA; The Department of Physiology, University of Maryland School of Medicine, Baltimore, MD, USA.
| | - Maura Greiser
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD, USA; The Department of Physiology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - W Jonathan Lederer
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD, USA; The Department of Physiology, University of Maryland School of Medicine, Baltimore, MD, USA.
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58
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Márta K, Hasan P, Rodríguez-Prados M, Paillard M, Hajnóczky G. Pharmacological inhibition of the mitochondrial Ca 2+ uniporter: Relevance for pathophysiology and human therapy. J Mol Cell Cardiol 2021; 151:135-144. [PMID: 33035551 PMCID: PMC7880870 DOI: 10.1016/j.yjmcc.2020.09.014] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Revised: 09/26/2020] [Accepted: 09/28/2020] [Indexed: 12/20/2022]
Abstract
Mitochondrial Ca2+ uptake has long been considered crucial for meeting the fluctuating energy demands of cells in the heart and other tissues. Increases in mitochondrial matrix [Ca2+] drive mitochondrial ATP production via stimulation of Ca2+-sensitive dehydrogenases. Mitochondria-targeted sensors have revealed mitochondrial matrix [Ca2+] rises that closely follow the cytoplasmic [Ca2+] signals in many paradigms. Mitochondrial Ca2+ uptake is mediated by the Ca2+ uniporter (mtCU). Pharmacological manipulation of the mtCU is potentially key to understanding its physiological significance, but no specific, cell-permeable inhibitors were identified. In the past decade, as the molecular identity of the mtCU was brought to light, efforts have focused on genetic targeting. However, in the cells/animals that are able to survive impaired mtCU function, robust compensatory changes were found in the mtCU as well as other mechanisms. Thus, the discovery, through chemical library screens on normal and mtCU-deficient cells, of new small-molecule inhibitors with improved cell permeability and specificity might offer a better chance to test the relevance of mitochondrial Ca2+ uptake. Success with the development of small molecule mtCU inhibitors is also expected to have clinical impact, considering the growing evidence for the role of mitochondrial Ca2+ uptake in a variety of diseases, including heart attack, stroke and various neurodegenerative disorders. Here, we review the progress in pharmacological targeting of mtCU and illustrate the challenges in this field using data obtained with MCU-i11, a new small molecule inhibitor.
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Affiliation(s)
- Katalin Márta
- MitoCare Center, Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Prottoy Hasan
- MitoCare Center, Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Macarena Rodríguez-Prados
- MitoCare Center, Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Melanie Paillard
- MitoCare Center, Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA 19107, USA; Univ-Lyon, CarMeN Laboratory, INSERM, INRA, Université Claude Bernard Lyon-1, INSA-Lyon, HCL, 69500 Bron, France
| | - György Hajnóczky
- MitoCare Center, Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA 19107, USA.
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59
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De Mario A, Gherardi G, Rizzuto R, Mammucari C. Skeletal muscle mitochondria in health and disease. Cell Calcium 2021; 94:102357. [PMID: 33550207 DOI: 10.1016/j.ceca.2021.102357] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 01/07/2021] [Accepted: 01/07/2021] [Indexed: 12/28/2022]
Abstract
Mitochondrial activity warrants energy supply to oxidative myofibres to sustain endurance workload. The maintenance of mitochondrial homeostasis is ensured by the control of fission and fusion processes and by the mitophagic removal of aberrant organelles. Many diseases are due to or characterized by dysfunctional mitochondria, and altered mitochondrial dynamics or turnover trigger myopathy per se. In this review, we will tackle the role of mitochondrial dynamics, turnover and metabolism in skeletal muscle, both in health and disease.
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Affiliation(s)
- Agnese De Mario
- Department of Biomedical Sciences, University of Padua, Padua, Italy
| | - Gaia Gherardi
- Department of Biomedical Sciences, University of Padua, Padua, Italy
| | - Rosario Rizzuto
- Department of Biomedical Sciences, University of Padua, Padua, Italy
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60
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Zambon AA, Lemaigre A, Phadke R, Grunewald S, Sewry C, Sarkozy A, Clement E, Muntoni F. Persistently elevated CK and lysosomal storage myopathy associated with mucolipin 1 defects. Neuromuscul Disord 2021; 31:212-217. [PMID: 33454187 DOI: 10.1016/j.nmd.2020.12.009] [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: 10/22/2020] [Revised: 12/07/2020] [Accepted: 12/18/2020] [Indexed: 12/13/2022]
Abstract
Mucolipidosis type IV is a rare autosomal recessive lysosomal storage disorder caused by bi-allelic pathogenic variants in the gene MCOLN1. This encodes for mucolipin-1 (ML1), an endo-lysosomal transmembrane Ca++ channel involved in vesicular trafficking. Although experimental models suggest that defects in mucolipin-1 can cause muscular dystrophy, putatively due to defective lysosomal-mediated sarcolemma repair, the role of mucolipin-1 in human muscle is still poorly deciphered. Elevation of creatine kinase (CK) had been reported in a few cases in the past but comprehensive descriptions of muscle pathology are lacking. Here we report a 7-year-old boy who underwent muscle biopsy due to persistently elevated CK levels (780-15,000 UI/L). Muscle pathology revealed features of a lysosomal storage myopathy with mild regenerative changes. Next generation sequencing confirmed homozygous nonsense variants in MCOLN1. This is a comprehensive pathological description of ML1-related myopathy, supporting the role of mucolipin-1 in muscle homoeostasis.
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Affiliation(s)
- Alberto A Zambon
- Dubowitz Neuromuscular Centre, UCL Great Ormond Street Institute of Child Health & Great Ormond Street Hospital, 30 Guilford Street, London WC1N 1EH, UK
| | - Alexandra Lemaigre
- Great Ormond Street Institute of Child Health & Great Ormond Street Hospital, London, UK
| | - Rahul Phadke
- Dubowitz Neuromuscular Centre, UCL Great Ormond Street Institute of Child Health & Great Ormond Street Hospital, 30 Guilford Street, London WC1N 1EH, UK
| | - Stephanie Grunewald
- Metabolic Department Great Ormond Street Hospital, UCL Great Ormond Street Institute of Child Health, London, UK
| | - Caroline Sewry
- Dubowitz Neuromuscular Centre, UCL Great Ormond Street Institute of Child Health & Great Ormond Street Hospital, 30 Guilford Street, London WC1N 1EH, UK
| | - Anna Sarkozy
- Dubowitz Neuromuscular Centre, UCL Great Ormond Street Institute of Child Health & Great Ormond Street Hospital, 30 Guilford Street, London WC1N 1EH, UK
| | - Emma Clement
- Great Ormond Street Institute of Child Health & Great Ormond Street Hospital, London, UK
| | - Francesco Muntoni
- Dubowitz Neuromuscular Centre, UCL Great Ormond Street Institute of Child Health & Great Ormond Street Hospital, 30 Guilford Street, London WC1N 1EH, UK; NIHR Great Ormond Street Hospital Biomedical Research Centre, Great Ormond Street Institute of Child Health, University College London, & Great Ormond Street Hospital Trust, London, UK.
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61
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Jahnke VE, Peterson JM, Van Der Meulen JH, Boehler J, Uaesoontrachoon K, Johnston HK, Defour A, Phadke A, Yu Q, Jaiswal JK, Nagaraju K. Mitochondrial dysfunction and consequences in calpain-3-deficient muscle. Skelet Muscle 2020; 10:37. [PMID: 33308300 PMCID: PMC7730798 DOI: 10.1186/s13395-020-00254-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Accepted: 11/16/2020] [Indexed: 01/19/2023] Open
Abstract
BACKGROUND Nonsense or loss-of-function mutations in the non-lysosomal cysteine protease calpain-3 result in limb-girdle muscular dystrophy type 2A (LGMD2A). While calpain-3 is implicated in muscle cell differentiation, sarcomere formation, and muscle cytoskeletal remodeling, the physiological basis for LGMD2A has remained elusive. METHODS Cell growth, gene expression profiling, and mitochondrial content and function were analyzed using muscle and muscle cell cultures established from healthy and calpain-3-deficient mice. Calpain-3-deficient mice were also treated with PPAR-delta agonist (GW501516) to assess mitochondrial function and membrane repair. The unpaired t test was used to assess the significance of the differences observed between the two groups or treatments. ANOVAs were used to assess significance over time. RESULTS We find that calpain-3 deficiency causes mitochondrial dysfunction in the muscles and myoblasts. Calpain-3-deficient myoblasts showed increased proliferation, and their gene expression profile showed aberrant mitochondrial biogenesis. Myotube gene expression analysis further revealed altered lipid metabolism in calpain-3-deficient muscle. Mitochondrial defects were validated in vitro and in vivo. We used GW501516 to improve mitochondrial biogenesis in vivo in 7-month-old calpain-3-deficient mice. This treatment improved satellite cell activity as indicated by increased MyoD and Pax7 mRNA expression. It also decreased muscle fatigability and reduced serum creatine kinase levels. The decreased mitochondrial function also impaired sarcolemmal repair in the calpain-3-deficient skeletal muscle. Improving mitochondrial activity by acute pyruvate treatment improved sarcolemmal repair. CONCLUSION Our results provide evidence that calpain-3 deficiency in the skeletal muscle is associated with poor mitochondrial biogenesis and function resulting in poor sarcolemmal repair. Addressing this deficit by drugs that improve mitochondrial activity offers new therapeutic avenues for LGMD2A.
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Affiliation(s)
- Vanessa E Jahnke
- Center for Genetic Medicine Research, Children's National Research Institute, Children's National Hospital, Washington, D.C., USA
| | - Jennifer M Peterson
- School of Exercise and Rehabilitation Sciences, The University of Toledo, Toledo, OH, USA
| | - Jack H Van Der Meulen
- Center for Genetic Medicine Research, Children's National Research Institute, Children's National Hospital, Washington, D.C., USA
| | - Jessica Boehler
- Center for Genetic Medicine Research, Children's National Research Institute, Children's National Hospital, Washington, D.C., USA
| | - Kitipong Uaesoontrachoon
- Center for Genetic Medicine Research, Children's National Research Institute, Children's National Hospital, Washington, D.C., USA
| | - Helen K Johnston
- Center for Genetic Medicine Research, Children's National Research Institute, Children's National Hospital, Washington, D.C., USA
- Department of Genomics and Precision Medicine, George Washington University School of Medicine and Health Sciences, Washington, D.C., USA
| | - Aurelia Defour
- Center for Genetic Medicine Research, Children's National Research Institute, Children's National Hospital, Washington, D.C., USA
| | - Aditi Phadke
- Center for Genetic Medicine Research, Children's National Research Institute, Children's National Hospital, Washington, D.C., USA
| | - Qing Yu
- Center for Genetic Medicine Research, Children's National Research Institute, Children's National Hospital, Washington, D.C., USA
| | - Jyoti K Jaiswal
- Center for Genetic Medicine Research, Children's National Research Institute, Children's National Hospital, Washington, D.C., USA
- Department of Genomics and Precision Medicine, George Washington University School of Medicine and Health Sciences, Washington, D.C., USA
| | - Kanneboyina Nagaraju
- Center for Genetic Medicine Research, Children's National Research Institute, Children's National Hospital, Washington, D.C., USA.
- Department of Genomics and Precision Medicine, George Washington University School of Medicine and Health Sciences, Washington, D.C., USA.
- School of Pharmacy and Pharmaceutical Sciences, SUNY Binghamton University, PO Box 6000, Binghamton, NY, 13902, USA.
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62
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Yang Y, Du J, Xu R, Shen Y, Yang D, Li D, Hu H, Pei H, Yang Y. Melatonin alleviates angiotensin-II-induced cardiac hypertrophy via activating MICU1 pathway. Aging (Albany NY) 2020; 13:493-515. [PMID: 33259334 PMCID: PMC7834983 DOI: 10.18632/aging.202159] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2020] [Accepted: 08/19/2020] [Indexed: 01/19/2023]
Abstract
Mitochondrial calcium uptake 1 (MICU1) is a pivotal molecule in maintaining mitochondrial homeostasis under stress conditions. However, it is unclear whether MICU1 attenuates mitochondrial stress in angiotensin II (Ang-II)-induced cardiac hypertrophy or if it has a role in the function of melatonin. Here, small-interfering RNAs against MICU1 or adenovirus-based plasmids encoding MICU1 were delivered into left ventricles of mice or incubated with neonatal murine ventricular myocytes (NMVMs) for 48 h. MICU1 expression was depressed in hypertrophic myocardia and MICU1 knockdown aggravated Ang-II-induced cardiac hypertrophy in vivo and in vitro. In contrast, MICU1 upregulation decreased cardiomyocyte susceptibility to hypertrophic stress. Ang-II administration, particularly in NMVMs with MICU1 knockdown, led to significantly increased reactive oxygen species (ROS) overload, altered mitochondrial morphology, and suppressed mitochondrial function, all of which were reversed by MICU1 supplementation. Moreover, peroxisome proliferator-activated receptor gamma coactivator 1-α (PGC-1α)/MICU1 expression in hypertrophic myocardia increased with melatonin. Melatonin ameliorated excessive ROS generation, promoted mitochondrial function, and attenuated cardiac hypertrophy in control but not MICU1 knockdown NMVMs or mice. Collectively, our results demonstrate that MICU1 attenuates Ang-II-induced cardiac hypertrophy by inhibiting mitochondria-derived oxidative stress. MICU1 activation may be the mechanism underlying melatonin-induced protection against myocardial hypertrophy.
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Affiliation(s)
- Yi Yang
- Department of Cardiology, The General Hospital of Western Theater Command, Chengdu 610083, China
| | - Jin Du
- Department of Cardiology, The General Hospital of Western Theater Command, Chengdu 610083, China
| | - Rui Xu
- Department of Cardiology, The General Hospital of Western Theater Command, Chengdu 610083, China
| | - Yang Shen
- Department of Cardiology, The General Hospital of Western Theater Command, Chengdu 610083, China
| | - Dachun Yang
- Department of Cardiology, The General Hospital of Western Theater Command, Chengdu 610083, China
| | - De Li
- Department of Cardiology, The General Hospital of Western Theater Command, Chengdu 610083, China
| | - Houxiang Hu
- Department of Cardiology, Affiliated Hospital of North Sichuan Medical College, Nanchong 637000, China
| | - Haifeng Pei
- Department of Cardiology, The General Hospital of Western Theater Command, Chengdu 610083, China
| | - Yongjian Yang
- Department of Cardiology, The General Hospital of Western Theater Command, Chengdu 610083, China
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63
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Gherardi G, Monticelli H, Rizzuto R, Mammucari C. The Mitochondrial Ca 2+ Uptake and the Fine-Tuning of Aerobic Metabolism. Front Physiol 2020; 11:554904. [PMID: 33117189 PMCID: PMC7575740 DOI: 10.3389/fphys.2020.554904] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Accepted: 09/14/2020] [Indexed: 12/13/2022] Open
Abstract
Recently, the role of mitochondrial activity in high-energy demand organs and in the orchestration of whole-body metabolism has received renewed attention. In mitochondria, pyruvate oxidation, ensured by efficient mitochondrial pyruvate entry and matrix dehydrogenases activity, generates acetyl CoA that enters the TCA cycle. TCA cycle activity, in turn, provides reducing equivalents and electrons that feed the electron transport chain eventually producing ATP. Mitochondrial Ca2+ uptake plays an essential role in the control of aerobic metabolism. Mitochondrial Ca2+ accumulation stimulates aerobic metabolism by inducing the activity of three TCA cycle dehydrogenases. In detail, matrix Ca2+ indirectly modulates pyruvate dehydrogenase via pyruvate dehydrogenase phosphatase 1, and directly activates isocitrate and α-ketoglutarate dehydrogenases. Here, we will discuss the contribution of mitochondrial Ca2+ uptake to the metabolic homeostasis of organs involved in systemic metabolism, including liver, skeletal muscle, and adipose tissue. We will also tackle the role of mitochondrial Ca2+ uptake in the heart, a high-energy consuming organ whose function strictly depends on appropriate Ca2+ signaling.
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Affiliation(s)
- Gaia Gherardi
- Department of Biomedical Sciences, University of Padua, Padua, Italy
| | | | - Rosario Rizzuto
- Department of Biomedical Sciences, University of Padua, Padua, Italy
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64
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Bittel AJ, Sreetama SC, Bittel DC, Horn A, Novak JS, Yokota T, Zhang A, Maruyama R, Rowel Q. Lim K, Jaiswal JK, Chen YW. Membrane Repair Deficit in Facioscapulohumeral Muscular Dystrophy. Int J Mol Sci 2020; 21:E5575. [PMID: 32759720 PMCID: PMC7432481 DOI: 10.3390/ijms21155575] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2020] [Revised: 07/28/2020] [Accepted: 07/30/2020] [Indexed: 12/14/2022] Open
Abstract
Deficits in plasma membrane repair have been identified in dysferlinopathy and Duchenne Muscular Dystrophy, and contribute to progressive myopathy. Although Facioscapulohumeral Muscular Dystrophy (FSHD) shares clinicopathological features with these muscular dystrophies, it is unknown if FSHD is characterized by plasma membrane repair deficits. Therefore, we exposed immortalized human FSHD myoblasts, immortalized myoblasts from unaffected siblings, and myofibers from a murine model of FSHD (FLExDUX4) to focal, pulsed laser ablation of the sarcolemma. Repair kinetics and success were determined from the accumulation of intracellular FM1-43 dye post-injury. We subsequently treated FSHD myoblasts with a DUX4-targeting antisense oligonucleotide (AON) to reduce DUX4 expression, and with the antioxidant Trolox to determine the role of DUX4 expression and oxidative stress in membrane repair. Compared to unaffected myoblasts, FSHD myoblasts demonstrate poor repair and a greater percentage of cells that failed to repair, which was mitigated by AON and Trolox treatments. Similar repair deficits were identified in FLExDUX4 myofibers. This is the first study to identify plasma membrane repair deficits in myoblasts from individuals with FSHD, and in myofibers from a murine model of FSHD. Our results suggest that DUX4 expression and oxidative stress may be important targets for future membrane-repair therapies.
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Affiliation(s)
- Adam J. Bittel
- Research Center for Genetic Medicine, Children’s National Hospital, 111 Michigan Ave NW, Washington, DC 20010, USA; (A.J.B.); (S.C.S.); (D.C.B.); (A.H.); (J.S.N.); (A.Z.)
| | - Sen Chandra Sreetama
- Research Center for Genetic Medicine, Children’s National Hospital, 111 Michigan Ave NW, Washington, DC 20010, USA; (A.J.B.); (S.C.S.); (D.C.B.); (A.H.); (J.S.N.); (A.Z.)
| | - Daniel C. Bittel
- Research Center for Genetic Medicine, Children’s National Hospital, 111 Michigan Ave NW, Washington, DC 20010, USA; (A.J.B.); (S.C.S.); (D.C.B.); (A.H.); (J.S.N.); (A.Z.)
| | - Adam Horn
- Research Center for Genetic Medicine, Children’s National Hospital, 111 Michigan Ave NW, Washington, DC 20010, USA; (A.J.B.); (S.C.S.); (D.C.B.); (A.H.); (J.S.N.); (A.Z.)
| | - James S. Novak
- Research Center for Genetic Medicine, Children’s National Hospital, 111 Michigan Ave NW, Washington, DC 20010, USA; (A.J.B.); (S.C.S.); (D.C.B.); (A.H.); (J.S.N.); (A.Z.)
- Department of Genomics and Precision Medicine, The George Washington University School of Medicine and Health Science, 111 Michigan Ave NW, Washington, DC 20010, USA
| | - Toshifumi Yokota
- Department of Medical Genetics, University of Alberta, 116 St. & 85 Ave., Edmonton, AB T6G 2R3, Canada; (T.Y.); (R.M.); (K.R.Q.L.)
| | - Aiping Zhang
- Research Center for Genetic Medicine, Children’s National Hospital, 111 Michigan Ave NW, Washington, DC 20010, USA; (A.J.B.); (S.C.S.); (D.C.B.); (A.H.); (J.S.N.); (A.Z.)
| | - Rika Maruyama
- Department of Medical Genetics, University of Alberta, 116 St. & 85 Ave., Edmonton, AB T6G 2R3, Canada; (T.Y.); (R.M.); (K.R.Q.L.)
| | - Kenji Rowel Q. Lim
- Department of Medical Genetics, University of Alberta, 116 St. & 85 Ave., Edmonton, AB T6G 2R3, Canada; (T.Y.); (R.M.); (K.R.Q.L.)
| | - Jyoti K. Jaiswal
- Research Center for Genetic Medicine, Children’s National Hospital, 111 Michigan Ave NW, Washington, DC 20010, USA; (A.J.B.); (S.C.S.); (D.C.B.); (A.H.); (J.S.N.); (A.Z.)
- Department of Integrative Systems Biology, Institute for Biomedical Sciences, The George Washington University, 2121 I St. NW, Washington, DC 20052, USA
| | - Yi-Wen Chen
- Research Center for Genetic Medicine, Children’s National Hospital, 111 Michigan Ave NW, Washington, DC 20010, USA; (A.J.B.); (S.C.S.); (D.C.B.); (A.H.); (J.S.N.); (A.Z.)
- Department of Integrative Systems Biology, Institute for Biomedical Sciences, The George Washington University, 2121 I St. NW, Washington, DC 20052, USA
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65
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Noble M, Lin QT, Sirko C, Houpt JA, Novello MJ, Stathopulos PB. Structural Mechanisms of Store-Operated and Mitochondrial Calcium Regulation: Initiation Points for Drug Discovery. Int J Mol Sci 2020; 21:E3642. [PMID: 32455637 PMCID: PMC7279490 DOI: 10.3390/ijms21103642] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Revised: 05/11/2020] [Accepted: 05/17/2020] [Indexed: 12/18/2022] Open
Abstract
Calcium (Ca2+) is a universal signaling ion that is essential for the life and death processes of all eukaryotes. In humans, numerous cell stimulation pathways lead to the mobilization of sarco/endoplasmic reticulum (S/ER) stored Ca2+, resulting in the propagation of Ca2+ signals through the activation of processes, such as store-operated Ca2+ entry (SOCE). SOCE provides a sustained Ca2+ entry into the cytosol; moreover, the uptake of SOCE-mediated Ca2+ by mitochondria can shape cytosolic Ca2+ signals, function as a feedback signal for the SOCE molecular machinery, and drive numerous mitochondrial processes, including adenosine triphosphate (ATP) production and distinct cell death pathways. In recent years, tremendous progress has been made in identifying the proteins mediating these signaling pathways and elucidating molecular structures, invaluable for understanding the underlying mechanisms of function. Nevertheless, there remains a disconnect between using this accumulating protein structural knowledge and the design of new research tools and therapies. In this review, we provide an overview of the Ca2+ signaling pathways that are involved in mediating S/ER stored Ca2+ release, SOCE, and mitochondrial Ca2+ uptake, as well as pinpoint multiple levels of crosstalk between these pathways. Further, we highlight the significant protein structures elucidated in recent years controlling these Ca2+ signaling pathways. Finally, we describe a simple strategy that aimed at applying the protein structural data to initiating drug design.
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Affiliation(s)
- Megan Noble
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, ON N6A5C1, Canada; (M.N.); (Q.-T.L.); (C.S.); (M.J.N.)
| | - Qi-Tong Lin
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, ON N6A5C1, Canada; (M.N.); (Q.-T.L.); (C.S.); (M.J.N.)
| | - Christian Sirko
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, ON N6A5C1, Canada; (M.N.); (Q.-T.L.); (C.S.); (M.J.N.)
| | - Jacob A. Houpt
- Department of Medicine, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, ON N6A5C1, Canada;
| | - Matthew J. Novello
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, ON N6A5C1, Canada; (M.N.); (Q.-T.L.); (C.S.); (M.J.N.)
| | - Peter B. Stathopulos
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, ON N6A5C1, Canada; (M.N.); (Q.-T.L.); (C.S.); (M.J.N.)
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66
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Wilton KM, Morales‐Rosado JA, Selcen D, Muthusamy K, Ewing S, Agre K, Nickels K, Klee EW, Ho M, Morava E. Developmental brain abnormalities and acute encephalopathy in a patient with myopathy with extrapyramidal signs secondary to pathogenic variants in MICU1. JIMD Rep 2020; 53:22-28. [PMID: 32395406 PMCID: PMC7203647 DOI: 10.1002/jmd2.12114] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2020] [Revised: 02/09/2020] [Accepted: 03/03/2020] [Indexed: 01/01/2023] Open
Abstract
Mitochondria play a variety of roles in the cell, far beyond their widely recognized role in ATP generation. One such role is the regulation and sequestration of calcium, which is done with the help of the mitochondrial calcium uniporter (MCU) and its regulators, MICU1 and MICU2. Genetic variations in MICU1 and MICU2 have been reported to cause myopathy, developmental disability and neurological symptoms typical of mitochondrial disorders. The symptoms of MICU1/2 deficiency have generally been attributed to calcium regulation in the metabolic and biochemical roles of mitochondria. Here, we report a female child with heterozygous MICU1 variants and multiple congenital brain malformations on MRI. Specifically, she shows anterior perisylvian polymicrogyria, dysmorphic basal ganglia, and cerebellar dysplasia in addition to white matter abnormalities. These novel findings suggest that MICU1 is necessary for proper neurodevelopment through a variety of potential mechanisms, including calcium-mediated regulation of the neuronal cytoskeleton, Miro1-MCU complex-mediated mitochondrial movement, or enhancing ATP production. This case provides new insight into the molecular pathogenesis of MCU dysfunction and may represent a novel diagnostic feature of calcium-based mitochondrial disease.
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Affiliation(s)
- Katelynn M. Wilton
- Medical Scientist Training Program, Mayo Clinic Alix College of MedicineMayo ClinicRochesterMinnesotaUSA
| | - Joel A. Morales‐Rosado
- Center for Individualized MedicineMayo ClinicRochesterMinnesotaUSA
- Department of Health Science Research, Division of Biomedical Statistics and InformaticsMayo ClinicRochesterMinnesotaUSA
| | - Duygu Selcen
- Department of NeurologyMayo ClinicRochesterMinnesotaUSA
| | | | - Sarah Ewing
- Department of Clinical GenomicsMayo ClinicRochesterMinnesotaUSA
| | - Katherine Agre
- Department of Clinical GenomicsMayo ClinicRochesterMinnesotaUSA
| | | | - Eric W. Klee
- Center for Individualized MedicineMayo ClinicRochesterMinnesotaUSA
- Department of Health Science Research, Division of Biomedical Statistics and InformaticsMayo ClinicRochesterMinnesotaUSA
- Department of Clinical GenomicsMayo ClinicRochesterMinnesotaUSA
| | - Mai‐Lan Ho
- Department of RadiologyNationwide Children's HospitalColumbusOhioUSA
| | - Eva Morava
- Center for Individualized MedicineMayo ClinicRochesterMinnesotaUSA
- Department of Clinical GenomicsMayo ClinicRochesterMinnesotaUSA
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67
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Garbincius JF, Luongo TS, Elrod JW. The debate continues - What is the role of MCU and mitochondrial calcium uptake in the heart? J Mol Cell Cardiol 2020; 143:163-174. [PMID: 32353353 DOI: 10.1016/j.yjmcc.2020.04.029] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Revised: 04/15/2020] [Accepted: 04/24/2020] [Indexed: 12/12/2022]
Abstract
Since the identification of the mitochondrial calcium uniporter (MCU) in 2011, several studies utilizing genetic models have attempted to decipher the role of mitochondrial calcium uptake in cardiac physiology. Confounding results in various mutant mouse models have led to an ongoing debate regarding the function of MCU in the heart. In this review, we evaluate and discuss the totality of evidence for mitochondrial calcium uptake in the cardiac stress response and highlight recent reports that implicate MCU in the control of homeostatic cardiac metabolism and function. This review concludes with a discussion of current gaps in knowledge and remaining experiments to define how MCU contributes to contractile function, cell death, metabolic regulation, and heart failure progression.
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Affiliation(s)
- Joanne F Garbincius
- Center for Translational Medicine, Lewis Katz School of Medicine at Temple University, Philadelphia, PA 19140, USA.
| | - Timothy S Luongo
- Center for Translational Medicine, Lewis Katz School of Medicine at Temple University, Philadelphia, PA 19140, USA.
| | - John W Elrod
- Center for Translational Medicine, Lewis Katz School of Medicine at Temple University, Philadelphia, PA 19140, USA.
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68
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Shally A, McDonagh B. The redox environment and mitochondrial dysfunction in age-related skeletal muscle atrophy. Biogerontology 2020; 21:461-473. [PMID: 32323076 DOI: 10.1007/s10522-020-09879-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Accepted: 04/09/2020] [Indexed: 12/12/2022]
Abstract
Medical advancements have extended human life expectancy, which is not always accompanied by an improved quality of life or healthspan. A decline in muscle mass and function is a consequence of ageing and can result in a loss of independence in elderly individuals while increasing their risk of falls. Multiple cellular pathways have been implicated in age-related muscle atrophy, including the contribution of reactive oxygen species (ROS) and disrupted redox signalling. Aberrant levels of ROS disrupts the redox environment in older muscle, potentially disrupting cellular signalling and in some cases blunting the adaptive response to exercise. Age-related muscle atrophy is associated with disrupted mitochondrial content and function, one of the hallmarks of age-related diseases. There is a critical link between abnormal ROS generation and dysfunctional mitochondrial dynamics including mitochondrial biogenesis, fusion and fission. In order to develop effective treatments or preventative strategies, it is important to gain a comprehensive understanding of the mechanistic pathways implicated in age associated loss of muscle.
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Affiliation(s)
- Alice Shally
- Discipline of Physiology, School of Medicine, National University of Ireland Galway, Galway, Ireland
| | - Brian McDonagh
- Discipline of Physiology, School of Medicine, National University of Ireland Galway, Galway, Ireland.
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