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Marzetti E, Calvani R, Coelho-Júnior HJ, Landi F, Picca A. Mitochondrial Quantity and Quality in Age-Related Sarcopenia. Int J Mol Sci 2024; 25:2052. [PMID: 38396729 PMCID: PMC10889427 DOI: 10.3390/ijms25042052] [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: 12/19/2023] [Revised: 02/01/2024] [Accepted: 02/06/2024] [Indexed: 02/25/2024] Open
Abstract
Sarcopenia, the age-associated decline in skeletal muscle mass and strength, is a condition with a complex pathophysiology. Among the factors underlying the development of sarcopenia are the progressive demise of motor neurons, the transition from fast to slow myosin isoform (type II to type I fiber switch), and the decrease in satellite cell number and function. Mitochondrial dysfunction has been indicated as a key contributor to skeletal myocyte decline and loss of physical performance with aging. Several systems have been implicated in the regulation of muscle plasticity and trophism such as the fine-tuned and complex regulation between the stimulator of protein synthesis, mechanistic target of rapamycin (mTOR), and the inhibitor of mTOR, AMP-activated protein kinase (AMPK), that promotes muscle catabolism. Here, we provide an overview of the molecular mechanisms linking mitochondrial signaling and quality with muscle homeostasis and performance and discuss the main pathways elicited by their imbalance during age-related muscle wasting. We also discuss lifestyle interventions (i.e., physical exercise and nutrition) that may be exploited to preserve mitochondrial function in the aged muscle. Finally, we illustrate the emerging possibility of rescuing muscle tissue homeostasis through mitochondrial transplantation.
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Affiliation(s)
- Emanuele Marzetti
- Fondazione Policlinico Universitario “Agostino Gemelli” IRCCS, L.go A. Gemelli 8, 00168 Rome, Italy; (R.C.); (F.L.)
- Department of Geriatrics, Orthopedics and Rheumatology, Università Cattolica del Sacro Cuore, L.go F. Vito 1, 00618 Rome, Italy;
| | - Riccardo Calvani
- Fondazione Policlinico Universitario “Agostino Gemelli” IRCCS, L.go A. Gemelli 8, 00168 Rome, Italy; (R.C.); (F.L.)
- Department of Geriatrics, Orthopedics and Rheumatology, Università Cattolica del Sacro Cuore, L.go F. Vito 1, 00618 Rome, Italy;
| | - Hélio José Coelho-Júnior
- Department of Geriatrics, Orthopedics and Rheumatology, Università Cattolica del Sacro Cuore, L.go F. Vito 1, 00618 Rome, Italy;
| | - Francesco Landi
- Fondazione Policlinico Universitario “Agostino Gemelli” IRCCS, L.go A. Gemelli 8, 00168 Rome, Italy; (R.C.); (F.L.)
- Department of Geriatrics, Orthopedics and Rheumatology, Università Cattolica del Sacro Cuore, L.go F. Vito 1, 00618 Rome, Italy;
| | - Anna Picca
- Fondazione Policlinico Universitario “Agostino Gemelli” IRCCS, L.go A. Gemelli 8, 00168 Rome, Italy; (R.C.); (F.L.)
- Department of Medicine and Surgery, LUM University, SS100 km 18, 70010 Casamassima, Italy
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2
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Zhang X, Gao F. Exercise improves vascular health: Role of mitochondria. Free Radic Biol Med 2021; 177:347-359. [PMID: 34748911 DOI: 10.1016/j.freeradbiomed.2021.11.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 10/20/2021] [Accepted: 11/02/2021] [Indexed: 01/10/2023]
Abstract
Vascular mitochondria constantly integrate signals from environment and respond accordingly to match vascular function to metabolic requirements of the organ tissues, while mitochondrial dysfunction contributes to vascular aging and pathologies such as atherosclerosis, stenosis, and hypertension. As an effective lifestyle intervention, exercise induces extensive mitochondrial adaptations through vascular mechanical stress and the increased production and release of reactive oxygen species and nitric oxide that activate multiple intracellular signaling pathways, among which peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) plays a critical role. PGC-1α coordinates mitochondrial quality control mechanisms to maintain a healthy mitochondrial pool and promote endothelial nitric oxide synthase activity in vasculature. The mitochondrial adaptations to exercise improve bioenergetics, balance redox status, protect endothelial cells against detrimental insults, increase vascular plasticity, and ameliorate aging-related vascular dysfunction, thus benefiting vascular health. This review highlights recent findings of mitochondria as a central hub integrating exercise-afforded vascular benefits and its underlying mechanisms. A better understanding of the mitochondrial adaptations to exercise will not only shed light on the mechanisms of exercise-induced cardiovascular protection, but may also provide new clues to mitochondria-oriented precise exercise prescriptions for cardiovascular health.
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Affiliation(s)
- Xing Zhang
- Key Laboratory of Aerospace Medicine of the Ministry of Education, School of Aerospace Medicine, Fourth Military Medical University, Xi'an, 710032, China.
| | - Feng Gao
- Key Laboratory of Aerospace Medicine of the Ministry of Education, School of Aerospace Medicine, Fourth Military Medical University, Xi'an, 710032, China.
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3
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Vaishali K, Kumar N, Rao V, Kovela RK, Sinha MK. Exercise and Mitochondrial Function: Importance and InferenceA Mini Review. Curr Mol Med 2021; 22:755-760. [PMID: 34844538 DOI: 10.2174/1566524021666211129110542] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 10/06/2021] [Accepted: 11/05/2021] [Indexed: 11/22/2022]
Abstract
Skeletal muscles must generate and distribute energy properly in order to function perfectly. Mitochondria in skeletal muscle cells form vast networks to meet this need, and their functions may improve as a result of exercise. In the present review, we discussed exercise-induced mitochondrial adaptations, age-related mitochondrial decline, and a biomarker as a mitochondrial function indicator and exercise interference.
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Affiliation(s)
- Vaishali K
- Department of Physiotherapy, Manipal College of Health Professions, Manipal Academy of Higher Education, Manipal, Karnataka. India
| | - Nitesh Kumar
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research, Hajipur, Bihar. India
| | - Vanishree Rao
- Department of Pharmacology, Manipal College of Pharmaceutical Sciences, Manipal Academy of Higher Education, Manipal, Karnataka. India
| | - Rakesh Krishna Kovela
- Department of Neurophysiotherapy, Ravi Nair Physiotherapy College, Datta Meghe Institute of Medical Sciences, Sawangi (Meghe), Wardha, Maharashtra. India
| | - Mukesh Kumar Sinha
- Department of Physiotherapy, Manipal College of Health Professions, Manipal Academy of Higher Education, Manipal, Karnataka. India
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Sutherland TC, Sefiani A, Horvat D, Huntington TE, Lei Y, West AP, Geoffroy CG. Age-Dependent Decline in Neuron Growth Potential and Mitochondria Functions in Cortical Neurons. Cells 2021; 10:1625. [PMID: 34209640 PMCID: PMC8306398 DOI: 10.3390/cells10071625] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 06/21/2021] [Accepted: 06/22/2021] [Indexed: 12/23/2022] Open
Abstract
The age of incidence of spinal cord injury (SCI) and the average age of people living with SCI is continuously increasing. However, SCI is extensively modeled in young adult animals, hampering translation of research to clinical applications. While there has been significant progress in manipulating axon growth after injury, the impact of aging is still unknown. Mitochondria are essential to successful neurite and axon growth, while aging is associated with a decline in mitochondrial functions. Using isolation and culture of adult cortical neurons, we analyzed mitochondrial changes in 2-, 6-, 12- and 18-month-old mice. We observed reduced neurite growth in older neurons. Older neurons also showed dysfunctional respiration, reduced membrane potential, and altered mitochondrial membrane transport proteins; however, mitochondrial DNA (mtDNA) abundance and cellular ATP were increased. Taken together, these data suggest that dysfunctional mitochondria in older neurons may be associated with the age-dependent reduction in neurite growth. Both normal aging and traumatic injury are associated with mitochondrial dysfunction, posing a challenge for an aging SCI population as the two elements can combine to worsen injury outcomes. The results of this study highlight this as an area of great interest in CNS trauma.
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Affiliation(s)
- Theresa C. Sutherland
- Department of Neuroscience and Experimental Therapeutics, Texas A&M Health Science Center, Bryan, TX 77807, USA; (T.C.S.); (A.S.); (D.H.); (T.E.H.)
| | - Arthur Sefiani
- Department of Neuroscience and Experimental Therapeutics, Texas A&M Health Science Center, Bryan, TX 77807, USA; (T.C.S.); (A.S.); (D.H.); (T.E.H.)
| | - Darijana Horvat
- Department of Neuroscience and Experimental Therapeutics, Texas A&M Health Science Center, Bryan, TX 77807, USA; (T.C.S.); (A.S.); (D.H.); (T.E.H.)
| | - Taylor E. Huntington
- Department of Neuroscience and Experimental Therapeutics, Texas A&M Health Science Center, Bryan, TX 77807, USA; (T.C.S.); (A.S.); (D.H.); (T.E.H.)
| | - Yuanjiu Lei
- Department of Microbial Pathogenesis and Immunology, Texas A&M Health Science Center, Bryan, TX 77807, USA; (Y.L.); (A.P.W.)
| | - A. Phillip West
- Department of Microbial Pathogenesis and Immunology, Texas A&M Health Science Center, Bryan, TX 77807, USA; (Y.L.); (A.P.W.)
| | - Cédric G. Geoffroy
- Department of Neuroscience and Experimental Therapeutics, Texas A&M Health Science Center, Bryan, TX 77807, USA; (T.C.S.); (A.S.); (D.H.); (T.E.H.)
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5
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Bellanti F, Lo Buglio A, Vendemiale G. Mitochondrial Impairment in Sarcopenia. BIOLOGY 2021; 10:biology10010031. [PMID: 33418869 PMCID: PMC7825073 DOI: 10.3390/biology10010031] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 12/21/2020] [Accepted: 12/25/2020] [Indexed: 02/07/2023]
Abstract
Sarcopenia is defined by the age-related loss of skeletal muscle quality, which relies on mitochondrial homeostasis. During aging, several mitochondrial features such as bioenergetics, dynamics, biogenesis, and selective autophagy (mitophagy) are altered and impinge on protein homeostasis, resulting in loss of muscle mass and function. Thus, mitochondrial dysfunction contributes significantly to the complex pathogenesis of sarcopenia, and mitochondria are indicated as potential targets to prevent and treat this age-related condition. After a concise presentation of the age-related modifications in skeletal muscle quality and mitochondrial homeostasis, the present review summarizes the most relevant findings related to mitochondrial alterations in sarcopenia.
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6
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Goyal S, Chaturvedi RK. Mitochondrial Protein Import Dysfunction in Pathogenesis of Neurodegenerative Diseases. Mol Neurobiol 2020; 58:1418-1437. [PMID: 33180216 DOI: 10.1007/s12035-020-02200-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 11/03/2020] [Indexed: 02/06/2023]
Abstract
Mitochondria play an essential role in maintaining energy homeostasis and cellular survival. In the brain, higher ATP production is required by mature neurons for communication. Most of the mitochondrial proteins transcribe in the nucleus and import in mitochondria through different pathways of the mitochondrial protein import machinery. This machinery plays a crucial role in determining mitochondrial morphology and functions through mitochondrial biogenesis. Failure of this machinery and any alterations during mitochondrial biogenesis underlies neurodegeneration resulting in Alzheimer's disease (AD), amyotrophic lateral sclerosis (ALS), and Parkinson's disease (PD) etc. Current knowledge has revealed the different pathways of mitochondrial protein import machinery such as translocase of the outer mitochondrial membrane complex, the presequence pathway, carrier pathway, β-barrel pathway, and mitochondrial import and assembly machinery etc. In this review, we have discussed the recent studies regarding protein import machinery, beyond the well-known effects of increased oxidative stress and bioenergetics dysfunctions. We have elucidated in detail how these types of machinery help to import and locate the precursor proteins to their specific location inside the mitochondria and play a major role in mitochondrial biogenesis. We further discuss their involvement in mitochondrial dysfunctioning and the induction of toxic aggregates in neurodegenerative diseases like AD and PD. The review supports the importance of import machinery in neuronal functions and its association with toxic aggregated proteins in mitochondrial impairment, suggesting a critical role in fostering and maintaining neurodegeneration and therapeutic response.
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Affiliation(s)
- Shweta Goyal
- Developmental Toxicology Laboratory, Systems Toxicology and Health Risk Assessment Group, CSIR-Indian Institute of Toxicology Research (CSIR-IITR), Vishvigyan Bhavan, 31, Mahatma Gandhi Marg, Lucknow, Uttar Pradesh, 226001, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - Rajnish Kumar Chaturvedi
- Developmental Toxicology Laboratory, Systems Toxicology and Health Risk Assessment Group, CSIR-Indian Institute of Toxicology Research (CSIR-IITR), Vishvigyan Bhavan, 31, Mahatma Gandhi Marg, Lucknow, Uttar Pradesh, 226001, India. .,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India.
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7
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Vesicular transport mediates the uptake of cytoplasmic proteins into mitochondria in Drosophila melanogaster. Nat Commun 2020; 11:2592. [PMID: 32444642 PMCID: PMC7244744 DOI: 10.1038/s41467-020-16335-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Accepted: 04/27/2020] [Indexed: 12/15/2022] Open
Abstract
Mitochondrial aging, which results in mitochondrial dysfunction, is strongly linked to many age-related diseases. Aging is associated with mitochondrial enlargement and transport of cytosolic proteins into mitochondria. The underlying homeostatic mechanisms that regulate mitochondrial morphology and function, and their breakdown during aging, remain unclear. Here, we identify a mitochondrial protein trafficking pathway in Drosophila melanogaster involving the mitochondria-associated protein Dosmit. Dosmit induces mitochondrial enlargement and the formation of double-membraned vesicles containing cytosolic protein within mitochondria. The rate of vesicle formation increases with age. Vesicles originate from the outer mitochondrial membrane as observed by tracking Tom20 localization, and the process is mediated by the mitochondria-associated Rab32 protein. Dosmit expression level is closely linked to the rate of ubiquitinated protein aggregation, which are themselves associated with age-related diseases. The mitochondrial protein trafficking route mediated by Dosmit offers a promising target for future age-related mitochondrial disease therapies. Mitochondrial dynamics change during ageing, with larger mitochondria and altered protein import in older animals. Here the authors show that Dosmit protein mediates mitochondrial morphology with Rab32 by inducing double-membraned vesicles that regulate protein trafficking into mitochondria.
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8
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Zhang Y, Oliveira AN, Hood DA. The intersection of exercise and aging on mitochondrial protein quality control. Exp Gerontol 2020; 131:110824. [PMID: 31911185 DOI: 10.1016/j.exger.2019.110824] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Revised: 12/13/2019] [Accepted: 12/31/2019] [Indexed: 12/23/2022]
Abstract
Skeletal muscle quality and quantity are negatively impacted with age. Part of this decline in function can be attributed to alterations in mitochondrial turnover, and in the mechanisms that regulate mitochondrial homeostasis. Protein quality control within the mitochondria relies on a number of interconnected processes, namely the mitochondrial unfolded protein response (UPRmt), protein import and mitophagy. In particular, the post-transcriptional regulation of protein import into the organelle has generated considerable recent interest in view of its dynamic versatility. The capacity for import can be increased by chronic exercise, and diminished by muscle disuse, and defects in the import pathway can be rescued by exercise. Within mitochondria, the unfolded protein response (UPR) is activated if protein import is altered, or if protein misfolding takes place. This UPR generates retrograde signaling to the nucleus to activate compensatory gene expression and protein synthesis. Mitophagy is also elevated with age, contributing to the lower mitochondrial content in aging muscle. However, mitophagy is amenable to exercise adaptations, as it is activated with each exercise bout, presumably to mediate mitochondrial quality control. However, this response is attenuated in older subjects. Although not yet completely elucidated, numerous molecular processes involved in mitochondrial biogenesis and turnover are affected with age. The contrasting and often opposite consequences of exercise and age suggest that exercise can serve as non-pharmacological "mitochondrial medicine" for aging muscle to ameliorate mitochondrial content and function, via pathways that implicate organelle protein quality control mechanisms.
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Affiliation(s)
- Yuan Zhang
- School of Sports and Health, Nanjing Sport Institute, Nanjing, Jiangsu, China
| | - Ashley N Oliveira
- Muscle Health Research Centre, School of Kinesiology and Health Science, York University, Toronto, Ontario M3J 1P3, Canada
| | - David A Hood
- Muscle Health Research Centre, School of Kinesiology and Health Science, York University, Toronto, Ontario M3J 1P3, Canada.
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9
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Impaired Mitochondrial Fusion and Oxidative Phosphorylation Triggered by High Glucose Is Mediated by Tom22 in Endothelial Cells. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2019; 2019:4508762. [PMID: 31236191 PMCID: PMC6545771 DOI: 10.1155/2019/4508762] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Revised: 02/22/2019] [Accepted: 03/18/2019] [Indexed: 11/18/2022]
Abstract
Much evidence demonstrates that mitochondrial dysfunction plays a crucial role in the pathogenesis of vascular complications of diabetes. However, the signaling pathways through which hyperglycemia leads to mitochondrial dysfunction of endothelial cells are not fully understood. Here, we treated human umbilical vein endothelial cells (HUVECs) with high glucose and examined the role of translocase of mitochondrial outer membrane (Tom) 22 on mitochondrial dynamics and cellular function. Impaired Tom22 expression and protein expression of oxidative phosphorylation (OXPHOS) as well as decreased mitochondrial fusion were observed in HUVECs treated with high glucose. The deletion of Tom22 resulted in reduced mitochondrial fusion and ATP production and increased apoptosis in HUVECs. The overexpression of Tom22 restored the balance of mitochondrial dynamics and OXPHOS disrupted by high glucose. Importantly, we found that Tom22 modulates mitochondrial dynamics and OXPHOS by interacting with mitofusin (Mfn) 1. Taken together, our findings demonstrate for the first time that Tom22 is a novel regulator of both mitochondrial dynamics and bioenergetic function and contributes to cell survival following high-glucose exposure.
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10
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Hood DA, Memme JM, Oliveira AN, Triolo M. Maintenance of Skeletal Muscle Mitochondria in Health, Exercise, and Aging. Annu Rev Physiol 2018; 81:19-41. [PMID: 30216742 DOI: 10.1146/annurev-physiol-020518-114310] [Citation(s) in RCA: 277] [Impact Index Per Article: 46.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Mitochondria are critical organelles responsible for regulating the metabolic status of skeletal muscle. These organelles exhibit remarkable plasticity by adapting their volume, structure, and function in response to chronic exercise, disuse, aging, and disease. A single bout of exercise initiates signaling to provoke increases in mitochondrial biogenesis, balanced by the onset of organelle turnover carried out by the mitophagy pathway. This accelerated turnover ensures the presence of a high functioning network of mitochondria designed for optimal ATP supply, with the consequence of favoring lipid metabolism, maintaining muscle mass, and reducing apoptotic susceptibility over the longer term. Conversely, aging and disuse are associated with reductions in muscle mass that are in part attributable to dysregulation of the mitochondrial network and impaired mitochondrial function. Therefore, exercise represents a viable, nonpharmaceutical therapy with the potential to reverse and enhance the impaired mitochondrial function observed with aging and chronic muscle disuse.
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Affiliation(s)
- David A Hood
- Muscle Health Research Centre, School of Kinesiology and Health Science, York University, Toronto, Ontario, M3J 1P3, Canada;
| | - Jonathan M Memme
- Muscle Health Research Centre, School of Kinesiology and Health Science, York University, Toronto, Ontario, M3J 1P3, Canada;
| | - Ashley N Oliveira
- Muscle Health Research Centre, School of Kinesiology and Health Science, York University, Toronto, Ontario, M3J 1P3, Canada;
| | - Matthew Triolo
- Muscle Health Research Centre, School of Kinesiology and Health Science, York University, Toronto, Ontario, M3J 1P3, Canada;
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11
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Perry CGR, Hawley JA. Molecular Basis of Exercise-Induced Skeletal Muscle Mitochondrial Biogenesis: Historical Advances, Current Knowledge, and Future Challenges. Cold Spring Harb Perspect Med 2018; 8:cshperspect.a029686. [PMID: 28507194 DOI: 10.1101/cshperspect.a029686] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
We provide an overview of groundbreaking studies that laid the foundation for our current understanding of exercise-induced mitochondrial biogenesis and its contribution to human skeletal muscle fitness. We highlight the mechanisms by which skeletal muscle responds to the acute perturbations in cellular energy homeostasis evoked by a single bout of endurance-based exercise and the adaptations resulting from the repeated demands of exercise training that ultimately promote mitochondrial biogenesis through hormetic feedback loops. Despite intense research efforts to elucidate the cellular mechanisms underpinning mitochondrial biogenesis in skeletal muscle, translating this basic knowledge into improved metabolic health at the population level remains a future challenge.
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Affiliation(s)
- Christopher G R Perry
- School of Kinesiology and Health Science, Muscle Health Research Centre, York University, Toronto, Ontario M3J 1P3, Canada
| | - John A Hawley
- Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne 3000, Australia.,Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Merseyside L3 5UA, United Kingdom
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12
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Hornberger TA, Carter HN, Hood DA, Figueiredo VC, Dupont-Versteegden EE, Peterson CA, McCarthy JJ, Camera DM, Hawley JA, Chaillou T, Cheng AJ, Nader GA, Wüst RCI, Houtkooper RH. Commentaries on Viewpoint: The rigorous study of exercise adaptations: Why mRNA might not be enough. J Appl Physiol (1985) 2018; 121:597-600. [PMID: 27543661 DOI: 10.1152/japplphysiol.00509.2016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Affiliation(s)
- Troy A Hornberger
- University of Wisconsin-MadisonYork UniversityUniversity of KentuckyAustralian Catholic UniversityAustralian Catholic University, Liverpool John Moores UniversityKarolinska InstitutetPennsylvania State UniversityAcademic Medical Center, University of Amsterdam
| | - Heather N Carter
- University of Wisconsin-MadisonYork UniversityUniversity of KentuckyAustralian Catholic UniversityAustralian Catholic University, Liverpool John Moores UniversityKarolinska InstitutetPennsylvania State UniversityAcademic Medical Center, University of Amsterdam
| | - David A Hood
- University of Wisconsin-MadisonYork UniversityUniversity of KentuckyAustralian Catholic UniversityAustralian Catholic University, Liverpool John Moores UniversityKarolinska InstitutetPennsylvania State UniversityAcademic Medical Center, University of Amsterdam
| | - Vandré Casagrande Figueiredo
- University of Wisconsin-MadisonYork UniversityUniversity of KentuckyAustralian Catholic UniversityAustralian Catholic University, Liverpool John Moores UniversityKarolinska InstitutetPennsylvania State UniversityAcademic Medical Center, University of Amsterdam
| | - Esther E Dupont-Versteegden
- University of Wisconsin-MadisonYork UniversityUniversity of KentuckyAustralian Catholic UniversityAustralian Catholic University, Liverpool John Moores UniversityKarolinska InstitutetPennsylvania State UniversityAcademic Medical Center, University of Amsterdam
| | - Charlotte A Peterson
- University of Wisconsin-MadisonYork UniversityUniversity of KentuckyAustralian Catholic UniversityAustralian Catholic University, Liverpool John Moores UniversityKarolinska InstitutetPennsylvania State UniversityAcademic Medical Center, University of Amsterdam
| | - John J McCarthy
- University of Wisconsin-MadisonYork UniversityUniversity of KentuckyAustralian Catholic UniversityAustralian Catholic University, Liverpool John Moores UniversityKarolinska InstitutetPennsylvania State UniversityAcademic Medical Center, University of Amsterdam
| | - Donny M Camera
- University of Wisconsin-MadisonYork UniversityUniversity of KentuckyAustralian Catholic UniversityAustralian Catholic University, Liverpool John Moores UniversityKarolinska InstitutetPennsylvania State UniversityAcademic Medical Center, University of Amsterdam
| | - John A Hawley
- University of Wisconsin-MadisonYork UniversityUniversity of KentuckyAustralian Catholic UniversityAustralian Catholic University, Liverpool John Moores UniversityKarolinska InstitutetPennsylvania State UniversityAcademic Medical Center, University of Amsterdam
| | - Thomas Chaillou
- University of Wisconsin-MadisonYork UniversityUniversity of KentuckyAustralian Catholic UniversityAustralian Catholic University, Liverpool John Moores UniversityKarolinska InstitutetPennsylvania State UniversityAcademic Medical Center, University of Amsterdam
| | - Arthur J Cheng
- University of Wisconsin-MadisonYork UniversityUniversity of KentuckyAustralian Catholic UniversityAustralian Catholic University, Liverpool John Moores UniversityKarolinska InstitutetPennsylvania State UniversityAcademic Medical Center, University of Amsterdam
| | - Gustavo A Nader
- University of Wisconsin-MadisonYork UniversityUniversity of KentuckyAustralian Catholic UniversityAustralian Catholic University, Liverpool John Moores UniversityKarolinska InstitutetPennsylvania State UniversityAcademic Medical Center, University of Amsterdam
| | - Rob C I Wüst
- University of Wisconsin-MadisonYork UniversityUniversity of KentuckyAustralian Catholic UniversityAustralian Catholic University, Liverpool John Moores UniversityKarolinska InstitutetPennsylvania State UniversityAcademic Medical Center, University of Amsterdam
| | - Riekelt H Houtkooper
- University of Wisconsin-MadisonYork UniversityUniversity of KentuckyAustralian Catholic UniversityAustralian Catholic University, Liverpool John Moores UniversityKarolinska InstitutetPennsylvania State UniversityAcademic Medical Center, University of Amsterdam
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13
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Impact of Aging and Exercise on Mitochondrial Quality Control in Skeletal Muscle. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2017; 2017:3165396. [PMID: 28656072 PMCID: PMC5471566 DOI: 10.1155/2017/3165396] [Citation(s) in RCA: 84] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Accepted: 05/03/2017] [Indexed: 12/17/2022]
Abstract
Mitochondria are characterized by its pivotal roles in managing energy production, reactive oxygen species, and calcium, whose aging-related structural and functional deteriorations are observed in aging muscle. Although it is still unclear how aging alters mitochondrial quality and quantity in skeletal muscle, dysregulation of mitochondrial biogenesis and dynamic controls has been suggested as key players for that. In this paper, we summarize current understandings on how aging regulates muscle mitochondrial biogenesis, while focusing on transcriptional regulations including PGC-1α, AMPK, p53, mtDNA, and Tfam. Further, we review current findings on the muscle mitochondrial dynamic systems in aging muscle: fusion/fission, autophagy/mitophagy, and protein import. Next, we also discuss how endurance and resistance exercises impact on the mitochondrial quality controls in aging muscle, suggesting possible effective exercise strategies to improve/maintain mitochondrial health.
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14
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Layne AS, Krehbiel LM, Mankowski RT, Anton SD, Leeuwenburgh C, Pahor M, Sandesara B, Wu SS, Buford TW. Resveratrol and exercise to treat functional limitations in late life: design of a randomized controlled trial. Contemp Clin Trials Commun 2017; 6:58-63. [PMID: 28944303 PMCID: PMC5608101 DOI: 10.1016/j.conctc.2017.03.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Revised: 02/20/2017] [Accepted: 03/12/2017] [Indexed: 11/22/2022] Open
Abstract
Skeletal muscle mitochondrial function declines with age and is a key factor in the maintenance of physical function among older adults. Research studies from animals and humans have consistently demonstrated that exercise improves skeletal muscle mitochondrial function in early and middle adulthood. However, mitochondrial adaptations to both acute and chronic exercise are attenuated in late life. Thus, there is an important need to identify adjuvant therapies capable of augmenting mitochondrial adaptations to exercise (e.g. improved mitochondrial respiration, muscle mitochondria biogenesis) among older adults. This study is investigating the potential of resveratrol supplementation for this purpose. The objective of this randomized, double-masked pilot trial is to evaluate the efficacy of resveratrol supplementation combined with a comprehensive supervised exercise program exercise for improving physical function among older adults. Moderately functioning, sedentary participants aged ≥60 years will perform 24 sessions (2 day/wk for 12 weeks) of center-based walking and resistance training and are randomly assigned to receive either (1) 500 mg/day resveratrol (2) 1000 mg/day resveratrol or (3) placebo. Study dependent outcomes include changes in 1) knee extensor strength, 2) objective measures of physical function (e.g. 4m walk test, Short Physical Performance Battery), 3) subjective measures of physical function assessed by Late Life Function and Disability Instrument, and 4) skeletal muscle mitochondrial function. This study will provide novel information regarding the therapeutic potential of resveratrol supplementation combined with exercise while also informing about the long-term clinical viability of the intervention by evaluating participant safety and willingness to engage in the intervention.
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15
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Koo JH, Cho JY, Lee UB. Treadmill exercise alleviates motor deficits and improves mitochondrial import machinery in an MPTP-induced mouse model of Parkinson's disease. Exp Gerontol 2017; 89:20-29. [PMID: 28062370 DOI: 10.1016/j.exger.2017.01.001] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Revised: 11/26/2016] [Accepted: 01/02/2017] [Indexed: 11/16/2022]
Abstract
Alpha-synuclein (α-Syn) accumulation is significantly correlated with motor deficits and mitochondrial dysfunction in Parkinson's disease (PD), but the molecular mechanism underlying its pathogenesis is unclear. In this study, we investigated the effects of treadmill exercise on motor deficits and mitochondrial dysfunction in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced mouse model of PD. Treadmill exercise inhibited dopaminergic neuron loss by promoting the expression of tyrosine hydroxylase (TH) and dopamine transporter (DAT) and seemed to improve cell survival by reducing α-Syn expression. Most importantly, treadmill exercise increased expression of the mitochondrial import machinery proteins TOM-40, TOM-20, and TIM-23. This was associated with decreased α-Syn expression and subsequent upregulation of the mitochondrial proteins COX-I, COX-IV, and mtHSP70. Taken together, these results indicate that treadmill exercise may ameliorate motor deficits and improve mitochondrial dysfunction by reducing α-Syn expression in the MPTP-induced mouse model of PD.
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Affiliation(s)
- Jung-Hoon Koo
- Department of Exercise Biochemistry, Korea National Sport University, Seoul 138-763, Republic of Korea; Institute of Sport Science, Korea National Sport University, Seoul, 138-763, Republic of Korea
| | - Joon-Yong Cho
- Department of Exercise Biochemistry, Korea National Sport University, Seoul 138-763, Republic of Korea
| | - Ung-Bae Lee
- Department of Beauty Health Science, Shinhan University, Gyeonggi-do, Republic of Korea.
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16
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Unravelling the mechanisms regulating muscle mitochondrial biogenesis. Biochem J 2016; 473:2295-314. [DOI: 10.1042/bcj20160009] [Citation(s) in RCA: 350] [Impact Index Per Article: 43.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Accepted: 04/18/2016] [Indexed: 11/17/2022]
Abstract
Skeletal muscle is a tissue with a low mitochondrial content under basal conditions, but it is responsive to acute increases in contractile activity patterns (i.e. exercise) which initiate the signalling of a compensatory response, leading to the biogenesis of mitochondria and improved organelle function. Exercise also promotes the degradation of poorly functioning mitochondria (i.e. mitophagy), thereby accelerating mitochondrial turnover, and preserving a pool of healthy organelles. In contrast, muscle disuse, as well as the aging process, are associated with reduced mitochondrial quality and quantity in muscle. This has strong negative implications for whole-body metabolic health and the preservation of muscle mass. A number of traditional, as well as novel regulatory pathways exist in muscle that control both biogenesis and mitophagy. Interestingly, although the ablation of single regulatory transcription factors within these pathways often leads to a reduction in the basal mitochondrial content of muscle, this can invariably be overcome with exercise, signifying that exercise activates a multitude of pathways which can respond to restore mitochondrial health. This knowledge, along with growing realization that pharmacological agents can also promote mitochondrial health independently of exercise, leads to an optimistic outlook in which the maintenance of mitochondrial and whole-body metabolic health can be achieved by taking advantage of the broad benefits of exercise, along with the potential specificity of drug action.
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17
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Erlich AT, Tryon LD, Crilly MJ, Memme JM, Moosavi ZSM, Oliveira AN, Beyfuss K, Hood DA. Function of specialized regulatory proteins and signaling pathways in exercise-induced muscle mitochondrial biogenesis. Integr Med Res 2016; 5:187-197. [PMID: 28462117 PMCID: PMC5390460 DOI: 10.1016/j.imr.2016.05.003] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Accepted: 05/04/2016] [Indexed: 12/19/2022] Open
Abstract
Skeletal muscle mitochondrial content and function are regulated by a number of specialized molecular pathways that remain to be fully defined. Although a number of proteins have been identified to be important for the maintenance of mitochondria in quiescent muscle, the requirement for these appears to decrease with the activation of multiple overlapping signaling events that are triggered by exercise. This makes exercise a valuable therapeutic tool for the treatment of mitochondrially based metabolic disorders. In this review, we summarize some of the traditional and more recently appreciated pathways that are involved in mitochondrial biogenesis in muscle, particularly during exercise.
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Affiliation(s)
| | | | | | | | | | | | | | - David A. Hood
- Corresponding author. Muscle Health Research Centre, School of Kinesiology and Health Science York University, Toronto, Ontario M3J1P3, Canada.
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18
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Carter HN, Chen CCW, Hood DA. Mitochondria, muscle health, and exercise with advancing age. Physiology (Bethesda) 2016; 30:208-23. [PMID: 25933821 DOI: 10.1152/physiol.00039.2014] [Citation(s) in RCA: 105] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Skeletal muscle health is dependent on the optimal function of its mitochondria. With advancing age, decrements in numerous mitochondrial variables are evident in muscle. Part of this decline is due to reduced physical activity, whereas the remainder appears to be attributed to age-related alterations in mitochondrial synthesis and degradation. Exercise is an important strategy to stimulate mitochondrial adaptations in older individuals to foster improvements in muscle function and quality of life.
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Affiliation(s)
- Heather N Carter
- Muscle Health Research Centre, School of Kinesiology and Health Science, York University, Toronto, Ontario, Canada
| | - Chris C W Chen
- Muscle Health Research Centre, School of Kinesiology and Health Science, York University, Toronto, Ontario, Canada
| | - David A Hood
- Muscle Health Research Centre, School of Kinesiology and Health Science, York University, Toronto, Ontario, Canada
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19
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Su J, Ekman C, Oskolkov N, Lahti L, Ström K, Brazma A, Groop L, Rung J, Hansson O. A novel atlas of gene expression in human skeletal muscle reveals molecular changes associated with aging. Skelet Muscle 2015; 5:35. [PMID: 26457177 PMCID: PMC4600214 DOI: 10.1186/s13395-015-0059-1] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Accepted: 09/28/2015] [Indexed: 12/17/2022] Open
Abstract
Background Although high-throughput studies of gene expression have generated large amounts of data, most of which is freely available in public archives, the use of this valuable resource is limited by computational complications and non-homogenous annotation. To address these issues, we have performed a complete re-annotation of public microarray data from human skeletal muscle biopsies and constructed a muscle expression compendium consisting of nearly 3000 samples. The created muscle compendium is a publicly available resource including all curated annotation. Using this data set, we aimed to elucidate the molecular mechanism of muscle aging and to describe how physical exercise may alleviate negative physiological effects. Results We find 957 genes to be significantly associated with aging (p < 0.05, FDR = 5 %, n = 361). Aging was associated with perturbation of many central metabolic pathways like mitochondrial function including reduced expression of genes in the ATP synthase, NADH dehydrogenase, cytochrome C reductase and oxidase complexes, as well as in glucose and pyruvate processing. Among the genes with the strongest association with aging were H3 histone, family 3B (H3F3B, p = 3.4 × 10−13), AHNAK nucleoprotein, desmoyokin (AHNAK, p = 6.9 × 10−12), and histone deacetylase 4 (HDAC4, p = 4.0 × 10−9). We also discover genes previously not linked to muscle aging and metabolism, such as fasciculation and elongation protein zeta 2 (FEZ2, p = 2.8 × 10−8). Out of the 957 genes associated with aging, 21 (p < 0.001, false discovery rate = 5 %, n = 116) were also associated with maximal oxygen consumption (VO2MAX). Strikingly, 20 out of those 21 genes are regulated in opposite direction when comparing increasing age with increasing VO2MAX. Conclusions These results support that mitochondrial dysfunction is a major age-related factor and also highlight the beneficial effects of maintaining a high physical capacity for prevention of age-related sarcopenia. Electronic supplementary material The online version of this article (doi:10.1186/s13395-015-0059-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Jing Su
- European Molecular Biology Laboratory-European Bioinformatics Institute, Wellcome Trust Genome Campus Hinxton, Cambridge, CB10 1SD UK
| | - Carl Ekman
- Lund University Diabetes Center, Department of Clinical Sciences, Diabetes and Endocrinology, Skåne University Hospital Malmö, Lund University, Malmö, 20502 Sweden
| | - Nikolay Oskolkov
- Lund University Diabetes Center, Department of Clinical Sciences, Diabetes and Endocrinology, Skåne University Hospital Malmö, Lund University, Malmö, 20502 Sweden
| | - Leo Lahti
- Department of Veterinary Biosciences, University of Helsinki, PO Box 66, FI-00014 Helsinki, Finland
| | - Kristoffer Ström
- Lund University Diabetes Center, Department of Clinical Sciences, Diabetes and Endocrinology, Skåne University Hospital Malmö, Lund University, Malmö, 20502 Sweden.,Swedish Winter Sports Research Centre, Department of Health Sciences, Mid Sweden University, SE-83125 Östersund, Sweden
| | - Alvis Brazma
- European Molecular Biology Laboratory-European Bioinformatics Institute, Wellcome Trust Genome Campus Hinxton, Cambridge, CB10 1SD UK
| | - Leif Groop
- Lund University Diabetes Center, Department of Clinical Sciences, Diabetes and Endocrinology, Skåne University Hospital Malmö, Lund University, Malmö, 20502 Sweden
| | - Johan Rung
- European Molecular Biology Laboratory-European Bioinformatics Institute, Wellcome Trust Genome Campus Hinxton, Cambridge, CB10 1SD UK.,Department of Immunology, Genetics and Pathology, Science for Life Laboratory, Rudbeck Laboratory, Uppsala University, 751 85 Uppsala, Sweden
| | - Ola Hansson
- Lund University Diabetes Center, Department of Clinical Sciences, Diabetes and Endocrinology, Skåne University Hospital Malmö, Lund University, Malmö, 20502 Sweden
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20
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Hepple RT. Mitochondrial involvement and impact in aging skeletal muscle. Front Aging Neurosci 2014; 6:211. [PMID: 25309422 PMCID: PMC4159998 DOI: 10.3389/fnagi.2014.00211] [Citation(s) in RCA: 102] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Accepted: 07/30/2014] [Indexed: 01/07/2023] Open
Abstract
Atrophy is a defining feature of aging skeletal muscle that contributes to progressive weakness and an increased risk of mobility impairment, falls, and physical frailty in very advanced age. Amongst the most frequently implicated mechanisms of aging muscle atrophy is mitochondrial dysfunction. Recent studies employing methods that are well-suited to interrogating intrinsic mitochondrial function find that mitochondrial respiration and reactive oxygen species emission changes are inconsistent between aging rat muscles undergoing atrophy and appear normal in human skeletal muscle from septuagenarian physically active subjects. On the other hand, a sensitization to permeability transition seems to be a general property of atrophying muscle with aging and this effect is even seen in atrophying muscle from physically active septuagenarian subjects. In addition to this intrinsic alteration in mitochondrial function, factors extrinsic to the mitochondria may also modulate mitochondrial function in aging muscle. In particular, recent evidence implicates oxidative stress in the aging milieu as a factor that depresses respiratory function in vivo (an effect that is not present ex vivo). Furthermore, in very advanced age, not only does muscle atrophy become more severe and clinically relevant in terms of its impact, but also there is evidence that this is driven by an accumulation of severely atrophied denervated myofibers. As denervation can itself modulate mitochondrial function and recruit mitochondrial-mediated atrophy pathways, future investigations need to address the degree to which skeletal muscle mitochondrial alterations in very advanced age are a consequence of denervation, rather than a primary organelle defect, to refine our understanding of the relevance of mitochondria as a therapeutic target at this more advanced age.
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Affiliation(s)
- Russell T Hepple
- Department of Kinesiology, McGill University Health Center, McGill University , Montreal, QC , Canada
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21
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Tom70 serves as a molecular switch to determine pathological cardiac hypertrophy. Cell Res 2014; 24:977-93. [PMID: 25022898 DOI: 10.1038/cr.2014.94] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2014] [Revised: 03/05/2014] [Accepted: 06/06/2014] [Indexed: 01/06/2023] Open
Abstract
Pathological cardiac hypertrophy is an inevitable forerunner of heart failure. Regardless of the etiology of cardiac hypertrophy, cardiomyocyte mitochondrial alterations are always observed in this context. The translocases of mitochondrial outer membrane (Tom) complex governs the import of mitochondrial precursor proteins to maintain mitochondrial function under pathophysiological conditions; however, its role in the development of pathological cardiac hypertrophy remains unclear. Here, we showed that Tom70 was downregulated in pathological hypertrophic hearts from humans and experimental animals. The reduction in Tom70 expression produced distinct pathological cardiomyocyte hypertrophy both in vivo and in vitro. The defective mitochondrial import of Tom70-targeted optic atrophy-1 triggered intracellular oxidative stress, which led to a pathological cellular response. Importantly, increased Tom70 levels provided cardiomyocytes with full resistance to diverse pro-hypertrophic insults. Together, these results reveal that Tom70 acts as a molecular switch that orchestrates hypertrophic stresses and mitochondrial responses to determine pathological cardiac hypertrophy.
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22
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Hood DA, Uguccioni G, Vainshtein A, D'souza D. Mechanisms of exercise-induced mitochondrial biogenesis in skeletal muscle: implications for health and disease. Compr Physiol 2013; 1:1119-34. [PMID: 23733637 DOI: 10.1002/cphy.c100074] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Mitochondria have paradoxical functions within cells. Essential providers of energy for cellular survival, they are also harbingers of cell death (apoptosis). Mitochondria exhibit remarkable dynamics, undergoing fission, fusion, and reticular expansion. Both nuclear and mitochondrial DNA (mtDNA) encode vital sets of proteins which, when incorporated into the inner mitochondrial membrane, provide electron transport capacity for ATP production, and when mutated lead to a broad spectrum of diseases. Acute exercise can activate a set of signaling cascades in skeletal muscle, leading to the activation of the gene expression pathway, from transcription, to post-translational modifications. Research has begun to unravel the important signals and their protein targets that trigger the onset of mitochondrial adaptations to exercise. Exercise training leads to an accumulation of nuclear- and mtDNA-encoded proteins that assemble into functional complexes devoted to mitochondrial respiration, reactive oxygen species (ROS) production, the import of proteins and metabolites, or apoptosis. This process of biogenesis has important consequences for metabolic health, the oxidative capacity of muscle, and whole body fitness. In contrast, the chronic muscle disuse that accompanies aging or muscle wasting diseases provokes a decline in mitochondrial content and function, which elicits excessive ROS formation and apoptotic signaling. Research continues to seek the molecular underpinnings of how regular exercise can be used to attenuate these decrements in organelle function, maintain skeletal muscle health, and improve quality of life.
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Affiliation(s)
- David A Hood
- School of Kinesiology and Health Science, York University, Toronto, Ontario, Canada.
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23
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Joseph AM, Adhihetty PJ, Buford TW, Wohlgemuth SE, Lees HA, Nguyen LMD, Aranda JM, Sandesara BD, Pahor M, Manini TM, Marzetti E, Leeuwenburgh C. The impact of aging on mitochondrial function and biogenesis pathways in skeletal muscle of sedentary high- and low-functioning elderly individuals. Aging Cell 2012; 11:801-9. [PMID: 22681576 DOI: 10.1111/j.1474-9726.2012.00844.x] [Citation(s) in RCA: 246] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
Abstract
Age-related loss of muscle mass and strength (sarcopenia) leads to a decline in physical function and frailty in the elderly. Among the many proposed underlying causes of sarcopenia, mitochondrial dysfunction is inherent in a variety of aged tissues. The intent of this study was to examine the effect of aging on key groups of regulatory proteins involved in mitochondrial biogenesis and how this relates to physical performance in two groups of sedentary elderly participants, classified as high- and low-functioning based on the Short Physical Performance Battery test. Muscle mass was decreased by 38% and 30% in low-functioning elderly (LFE) participants when compared to young and high-functioning elderly participants, respectively, and positively correlated to physical performance. Mitochondrial respiration in permeabilized muscle fibers was reduced (41%) in the LFE group when compared to the young, and this was associated with a 30% decline in cytochrome c oxidase activity. Levels of key metabolic regulators, SIRT3 and PGC-1α, were significantly reduced (50%) in both groups of elderly participants when compared to young. Similarly, the fusion protein OPA1 was lower in muscle from elderly subjects; however, no changes were detected in Mfn2, Drp1 or Fis1 among the groups. In contrast, protein import machinery components Tom22 and cHsp70 were increased in the LFE group when compared to the young. This study suggests that aging in skeletal muscle is associated with impaired mitochondrial function and altered biogenesis pathways and that this may contribute to muscle atrophy and the decline in muscle performance observed in the elderly population.
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Affiliation(s)
- Anna-Maria Joseph
- Department of Aging and Geriatric Research, University of Florida, Gainesville, FL 32610, USA
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24
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Joseph AM, Hood DA. Plasticity of TOM complex assembly in skeletal muscle mitochondria in response to chronic contractile activity. Mitochondrion 2011; 12:305-12. [PMID: 22142511 DOI: 10.1016/j.mito.2011.11.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2011] [Revised: 11/10/2011] [Accepted: 11/17/2011] [Indexed: 10/15/2022]
Abstract
We investigated the assembly of the TOM complex within skeletal muscle under conditions of chronic contractile activity-induced mitochondrial biogenesis. Tom40 import into mitochondria was increased by chronic contractile activity, as was its time-dependent assembly into the TOM complex. These changes coincided with contractile activity-induced augmentations in the expression of key protein import machinery components Tim17, Tim23, and Tom22, as well as the cytosolic chaperone Hsp90. These data indicate the adaptability of the TOM protein import complex and suggest a regulatory role for the assembly of this complex in exercise-induced mitochondrial biogenesis.
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Affiliation(s)
- Anna-Maria Joseph
- Department of Biology, York University, Toronto, Ontario, Canada M3J 1P3
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25
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Picard M, Taivassalo T, Ritchie D, Wright KJ, Thomas MM, Romestaing C, Hepple RT. Mitochondrial structure and function are disrupted by standard isolation methods. PLoS One 2011; 6:e18317. [PMID: 21512578 PMCID: PMC3065478 DOI: 10.1371/journal.pone.0018317] [Citation(s) in RCA: 225] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2011] [Accepted: 02/24/2011] [Indexed: 01/28/2023] Open
Abstract
Mitochondria regulate critical components of cellular function via ATP production, reactive oxygen species production, Ca2+ handling and apoptotic signaling. Two classical methods exist to study mitochondrial function of skeletal muscles: isolated mitochondria and permeabilized myofibers. Whereas mitochondrial isolation removes a portion of the mitochondria from their cellular environment, myofiber permeabilization preserves mitochondrial morphology and functional interactions with other intracellular components. Despite this, isolated mitochondria remain the most commonly used method to infer in vivo mitochondrial function. In this study, we directly compared measures of several key aspects of mitochondrial function in both isolated mitochondria and permeabilized myofibers of rat gastrocnemius muscle. Here we show that mitochondrial isolation i) induced fragmented organelle morphology; ii) dramatically sensitized the permeability transition pore sensitivity to a Ca2+ challenge; iii) differentially altered mitochondrial respiration depending upon the respiratory conditions; and iv) dramatically increased H2O2 production. These alterations are qualitatively similar to the changes in mitochondrial structure and function observed in vivo after cellular stress-induced mitochondrial fragmentation, but are generally of much greater magnitude. Furthermore, mitochondrial isolation markedly altered electron transport chain protein stoichiometry. Collectively, our results demonstrate that isolated mitochondria possess functional characteristics that differ fundamentally from those of intact mitochondria in permeabilized myofibers. Our work and that of others underscores the importance of studying mitochondrial function in tissue preparations where mitochondrial structure is preserved and all mitochondria are represented.
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Affiliation(s)
- Martin Picard
- Department of Kinesiology, McGill University, Montreal, Quebec, Canada
| | - Tanja Taivassalo
- Department of Kinesiology, McGill University, Montreal, Quebec, Canada
| | - Darmyn Ritchie
- Muscle and Aging Laboratory, Faculty of Kinesiology and Faculty of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Kathryn J. Wright
- Muscle and Aging Laboratory, Faculty of Kinesiology and Faculty of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Melissa M. Thomas
- Muscle and Aging Laboratory, Faculty of Kinesiology and Faculty of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Caroline Romestaing
- Laboratoire de Physiologie Intégrative, Cellulaire et Moléculaire, Université de Lyon, Villeurbanne, France
| | - Russell T. Hepple
- Muscle and Aging Laboratory, Faculty of Kinesiology and Faculty of Medicine, University of Calgary, Calgary, Alberta, Canada
- * E-mail:
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26
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Singh K, Hood DA. Effect of denervation-induced muscle disuse on mitochondrial protein import. Am J Physiol Cell Physiol 2011; 300:C138-45. [DOI: 10.1152/ajpcell.00181.2010] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
This study determined whether muscle disuse affects mitochondrial protein import and whether changes in protein import are related to mitochondrial content and function. Protein import was measured using a model of unilateral peroneal nerve denervation in rats for 3 ( n = 10), 7 ( n = 12), or 14 ( n = 14) days. We compared the import of preproteins into the matrix of subsarcolemmal (SS) and intermyofibrillar (IMF) mitochondria isolated from the denervated and the contralateral control tibialis anterior muscles. Denervation led to 50% and 29% reductions in protein import after 14 days of disuse in SS and IMF mitochondria, respectively. This was accompanied by significant decreases in mitochondrial state 3 respiration, muscle mass, and whole muscle cytochrome c oxidase activity. To investigate the mechanisms involved, we assessed disuse-related changes in 1) protein import machinery components and 2) mitochondrial function, reflected by respiration and reactive oxygen species (ROS) production. Denervation significantly reduced the expression of translocases localized in the inner membrane (Tim23), outer membrane (Tom20), and mitochondrial heat shock protein 70 (mtHsp70), especially in the SS subfraction. Denervation also resulted in elevated ROS generation, and exogenous ROS was found to markedly reduce protein import. Thus our data indicate that protein import kinetics are closely related to alterations in mitochondrial respiratory capacity ( r = 0.95) and are negatively impacted by ROS. Deleterious changes in the protein import system likely facilitate the reduction in mitochondrial content and the increase in organelle dysfunction (i.e., increased ROS production and decreased respiration) during chronic disuse, which likely contribute to the activation of degradative pathways leading to muscle atrophy.
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Affiliation(s)
- Kaustabh Singh
- Muscle Health Research Center,
- School of Kinesiology and Health Science, and
| | - David A. Hood
- Muscle Health Research Center,
- School of Kinesiology and Health Science, and
- Department of Biology, York University, Toronto, Ontario, Canada
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27
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Hepple RT. Mitochondrial protein import in aging muscle: can Tom still do it? Focus on "Biogenesis of the mitochondrial Tom40 channel in skeletal muscle from aged animals and its adaptability to chronic contractile activity". Am J Physiol Cell Physiol 2010; 298:C1298-300. [PMID: 20219952 DOI: 10.1152/ajpcell.00070.2010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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28
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Huang JH, Joseph AM, Ljubicic V, Iqbal S, Hood DA. Effect of age on the processing and import of matrix-destined mitochondrial proteins in skeletal muscle. J Gerontol A Biol Sci Med Sci 2010; 65:138-46. [PMID: 20045872 DOI: 10.1093/gerona/glp201] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Deregulation of muscle mitochondrial biogenesis may explain the altered mitochondrial properties associated with aging. Maintenance of the mitochondrial network requires the continuous incorporation of nascent proteins into their subcompartments via the protein import pathway. We examined whether this pathway was impaired in muscle of aged animals, focusing on the subsarcolemmal and intermyofibrillar mitochondrial populations. Our results indicate that the import of proteins into the mitochondrial matrix was unaltered with age. Interestingly, import assays supplemented with the cytosolic fraction illustrated an attenuation of protein import, and this effect was similar between age groups. We observed a 2.5-fold increase in protein degradation in the presence of the cytosolic fraction obtained from aged animals. Thus, the reduction of mitochondrial content and/or function observed with aging may not rely on altered activity of the import pathway but rather on the availability of preproteins that are susceptible to elevated rates of degradation by cytosolic factors.
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Affiliation(s)
- Julianna H Huang
- School of Kinesiology & Health Science, York University, 4700 Keele Street, Toronto, Ontario, Canada
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