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Warneke K, Behm DG, Alizadeh S, Hillebrecht M, Konrad A, Wirth K. Discussing Conflicting Explanatory Approaches in Flexibility Training Under Consideration of Physiology: A Narrative Review. Sports Med 2024:10.1007/s40279-024-02043-y. [PMID: 38819597 DOI: 10.1007/s40279-024-02043-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/01/2024] [Indexed: 06/01/2024]
Abstract
The mechanisms underlying range of motion enhancements via flexibility training discussed in the literature show high heterogeneity in research methodology and study findings. In addition, scientific conclusions are mostly based on functional observations while studies considering the underlying physiology are less common. However, understanding the underlying mechanisms that contribute to an improved range of motion through stretching is crucial for conducting comparable studies with sound designs, optimising training routines and accurately interpreting resulting outcomes. While there seems to be no evidence to attribute acute range of motion increases as well as changes in muscle and tendon stiffness and pain perception specifically to stretching or foam rolling, the role of general warm-up effects is discussed in this paper. Additionally, the role of mechanical tension applied to greater muscle lengths for range of motion improvement will be discussed. Thus, it is suggested that physical training stressors can be seen as external stimuli that control gene expression via the targeted stimulation of transcription factors, leading to structural adaptations due to enhanced protein synthesis. Hence, the possible role of serial sarcomerogenesis in altering pain perception, reducing muscle stiffness and passive torque, or changes in the optimal joint angle for force development is considered as well as alternative interventions with a potential impact on anabolic pathways. As there are limited possibilities to directly measure serial sarcomere number, longitudinal muscle hypertrophy remains without direct evidence. The available literature does not demonstrate the necessity of only using specific flexibility training routines such as stretching to enhance acute or chronic range of motion.
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Affiliation(s)
- Konstantin Warneke
- Institute of Human Movement Science, Sport and Health, University of Graz, Graz, Austria.
- Department of Movement Sciences, Institute of Sport Science, University of Klagenfurt, Universitatsstraße 65, 9020, Klagenfurt Am Wörthersee, Austria.
- School of Human Kinetics and Recreation, Memorial University of Newfoundland, St. John's, NL, Canada.
| | - David G Behm
- School of Human Kinetics and Recreation, Memorial University of Newfoundland, St. John's, NL, Canada
| | - Shahab Alizadeh
- School of Human Kinetics and Recreation, Memorial University of Newfoundland, St. John's, NL, Canada
- Human Performance Lab, Department of Kinesiology, University of Calgary, Calgary, AB, Canada
| | - Martin Hillebrecht
- University Sports Center, Carl Von Ossietzky University Oldenburg, Oldenburg, Germany
| | - Andreas Konrad
- School of Human Kinetics and Recreation, Memorial University of Newfoundland, St. John's, NL, Canada
- University Sports Center, Carl Von Ossietzky University Oldenburg, Oldenburg, Germany
| | - Klaus Wirth
- University of Applied Sciences Wiener Neustadt, Vienna, Austria
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Ismaeel A, Thomas NT, McCashland M, Vechetti IJ, Edman S, Lanner JT, Figueiredo VC, Fry CS, McCarthy JJ, Wen Y, Murach KA, von Walden F. Coordinated Regulation of Myonuclear DNA Methylation, mRNA, and miRNA Levels Associates With the Metabolic Response to Rapid Synergist Ablation-Induced Skeletal Muscle Hypertrophy in Female Mice. FUNCTION 2023; 5:zqad062. [PMID: 38020067 PMCID: PMC10666992 DOI: 10.1093/function/zqad062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 10/16/2023] [Accepted: 11/01/2023] [Indexed: 12/01/2023] Open
Abstract
The central dogma of molecular biology dictates the general flow of molecular information from DNA that leads to a functional cellular outcome. In skeletal muscle fibers, the extent to which global myonuclear transcriptional alterations, accounting for epigenetic and post-transcriptional influences, contribute to an adaptive stress response is not clearly defined. In this investigation, we leveraged an integrated analysis of the myonucleus-specific DNA methylome and transcriptome, as well as myonuclear small RNA profiling to molecularly define the early phase of skeletal muscle fiber hypertrophy. The analysis of myonucleus-specific mature microRNA and other small RNA species provides new directions for exploring muscle adaptation and complemented the methylation and transcriptional information. Our integrated multi-omics interrogation revealed a coordinated myonuclear molecular landscape during muscle loading that coincides with an acute and rapid reduction of oxidative metabolism. This response may favor a biosynthesis-oriented metabolic program that supports rapid hypertrophic growth.
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Affiliation(s)
- Ahmed Ismaeel
- Department of Physiology, College of Medicine, University of Kentucky, Lexington, KY 40508, USA
- Center for Muscle Biology, University of Kentucky, Lexington, KY 40536, USA
| | - Nicholas T Thomas
- Center for Muscle Biology, University of Kentucky, Lexington, KY 40536, USA
- Department of Athletic Training and Clinical Nutrition, College of Health Sciences, University of Kentucky, Lexington, KY 40536, USA
| | - Mariah McCashland
- Department of Nutrition and Health Sciences, University of Nebraska–Lincoln, Lincoln, NE 68583, USA
| | - Ivan J Vechetti
- Department of Nutrition and Health Sciences, University of Nebraska–Lincoln, Lincoln, NE 68583, USA
| | - Sebastian Edman
- Department of Women’s and Children’s Health, Karolinska Institutet, Solna 17177, Sweden
| | - Johanna T Lanner
- Department of Physiology and Pharmacology, Karolinska Institutet, Solna 17177, Sweden
| | - Vandré C Figueiredo
- Department of Biological Sciences, Oakland University, Rochester, MI 48309, USA
| | - Christopher S Fry
- Center for Muscle Biology, University of Kentucky, Lexington, KY 40536, USA
- Department of Athletic Training and Clinical Nutrition, College of Health Sciences, University of Kentucky, Lexington, KY 40536, USA
| | - John J McCarthy
- Department of Physiology, College of Medicine, University of Kentucky, Lexington, KY 40508, USA
- Center for Muscle Biology, University of Kentucky, Lexington, KY 40536, USA
| | - Yuan Wen
- Department of Physiology, College of Medicine, University of Kentucky, Lexington, KY 40508, USA
- Center for Muscle Biology, University of Kentucky, Lexington, KY 40536, USA
- Division of Biomedical Informatics, Department of Internal Medicine, College of Medicine, University of Kentucky, Lexington, KY 40536, USA
| | - Kevin A Murach
- Department of Health, Human Performance, and Recreation, Exercise Science Research Center, University of Arkansas, Fayetteville, AR 72701, USA
| | - Ferdinand von Walden
- Department of Women’s and Children’s Health, Karolinska Institutet, Solna 17177, Sweden
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Li AL, Lian L, Chen XN, Cai WH, Fan XB, Fan YJ, Li TT, Xie YY, Zhang JP. The role of mitochondria in myocardial damage caused by energy metabolism disorders: From mechanisms to therapeutics. Free Radic Biol Med 2023; 208:236-251. [PMID: 37567516 DOI: 10.1016/j.freeradbiomed.2023.08.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Revised: 07/24/2023] [Accepted: 08/03/2023] [Indexed: 08/13/2023]
Abstract
Myocardial damage is the most serious pathological consequence of cardiovascular diseases and an important reason for their high mortality. In recent years, because of the high prevalence of systemic energy metabolism disorders (e.g., obesity, diabetes mellitus, and metabolic syndrome), complications of myocardial damage caused by these disorders have attracted widespread attention. Energy metabolism disorders are independent of traditional injury-related risk factors, such as ischemia, hypoxia, trauma, and infection. An imbalance of myocardial metabolic flexibility and myocardial energy depletion are usually the initial changes of myocardial injury caused by energy metabolism disorders, and abnormal morphology and functional destruction of the mitochondria are their important features. Specifically, mitochondria are the centers of energy metabolism, and recent evidence has shown that decreased mitochondrial function, caused by an imbalance in mitochondrial quality control, may play a key role in myocardial injury caused by energy metabolism disorders. Under chronic energy stress, mitochondria undergo pathological fission, while mitophagy, mitochondrial fusion, and biogenesis are inhibited, and mitochondrial protein balance and transfer are disturbed, resulting in the accumulation of nonfunctional and damaged mitochondria. Consequently, damaged mitochondria lead to myocardial energy depletion and the accumulation of large amounts of reactive oxygen species, further aggravating the imbalance in mitochondrial quality control and forming a vicious cycle. In addition, impaired mitochondria coordinate calcium homeostasis imbalance, and epigenetic alterations participate in the pathogenesis of myocardial damage. These pathological changes induce rapid progression of myocardial damage, eventually leading to heart failure or sudden cardiac death. To intervene more specifically in the myocardial damage caused by metabolic disorders, we need to understand the specific role of mitochondria in this context in detail. Accordingly, promising therapeutic strategies have been proposed. We also summarize the existing therapeutic strategies to provide a reference for clinical treatment and developing new therapies.
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Affiliation(s)
- Ao-Lin Li
- First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, Tianjin, 300183, China; National Clinical Research Center for Chinese Medicine Acupuncture and Moxibustion, Tianjin, 300193, China; Tianjin University of Traditional Chinese Medicine, Tianjin, 300193, China
| | - Lu Lian
- First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, Tianjin, 300183, China; National Clinical Research Center for Chinese Medicine Acupuncture and Moxibustion, Tianjin, 300193, China; Tianjin University of Traditional Chinese Medicine, Tianjin, 300193, China
| | - Xin-Nong Chen
- Department of Traditional Chinese Medicine, Tianjin First Central Hospital, Tianjin, 300190, China
| | - Wen-Hui Cai
- First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, Tianjin, 300183, China; National Clinical Research Center for Chinese Medicine Acupuncture and Moxibustion, Tianjin, 300193, China; Tianjin University of Traditional Chinese Medicine, Tianjin, 300193, China
| | - Xin-Biao Fan
- First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, Tianjin, 300183, China; National Clinical Research Center for Chinese Medicine Acupuncture and Moxibustion, Tianjin, 300193, China; Tianjin University of Traditional Chinese Medicine, Tianjin, 300193, China
| | - Ya-Jie Fan
- First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, Tianjin, 300183, China; National Clinical Research Center for Chinese Medicine Acupuncture and Moxibustion, Tianjin, 300193, China; Tianjin University of Traditional Chinese Medicine, Tianjin, 300193, China
| | - Ting-Ting Li
- First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, Tianjin, 300183, China; National Clinical Research Center for Chinese Medicine Acupuncture and Moxibustion, Tianjin, 300193, China; Tianjin University of Traditional Chinese Medicine, Tianjin, 300193, China
| | - Ying-Yu Xie
- College of Traditional Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin, 300193, China.
| | - Jun-Ping Zhang
- First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, Tianjin, 300183, China.
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Ismaeel A, Valentino TR, Burke B, Goh J, Saliu TP, Albathi F, Owen A, McCarthy JJ, Wen Y. Acetate and succinate benefit host muscle energetics as exercise-associated post-biotics. Physiol Rep 2023; 11:e15848. [PMID: 37940330 PMCID: PMC10632089 DOI: 10.14814/phy2.15848] [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: 10/13/2023] [Revised: 10/19/2023] [Accepted: 10/19/2023] [Indexed: 11/10/2023] Open
Abstract
Recently, the gut microbiome has emerged as a potent modulator of exercise-induced systemic adaptation and appears to be crucial for mediating some of the benefits of exercise. This study builds upon previous evidence establishing a gut microbiome-skeletal muscle axis, identifying exercise-induced changes in microbiome composition. Metagenomics sequencing of fecal samples from non-exercise-trained controls or exercise-trained mice was conducted. Biodiversity indices indicated exercise training did not change alpha diversity. However, there were notable differences in beta-diversity between trained and untrained microbiomes. Exercise significantly increased the level of the bacterial species Muribaculaceae bacterium DSM 103720. Computation simulation of bacterial growth was used to predict metabolites that accumulate under in silico culture of exercise-responsive bacteria. We identified acetate and succinate as potential gut microbial metabolites that are produced by Muribaculaceae bacterium, which were then administered to mice during a period of mechanical overload-induced muscle hypertrophy. Although no differences were observed for the overall muscle growth response to succinate or acetate administration during the first 5 days of mechanical overload-induced hypertrophy, acetate and succinate increased skeletal muscle mitochondrial respiration. When given as post-biotics, succinate or acetate treatment may improve oxidative metabolism during muscle hypertrophy.
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Affiliation(s)
- Ahmed Ismaeel
- Department of Physiology, College of MedicineUniversity of KentuckyLexingtonKentuckyUSA
- Center for Muscle BiologyUniversity of KentuckyLexingtonKentuckyUSA
| | | | - Benjamin Burke
- Department of Physiology, College of MedicineUniversity of KentuckyLexingtonKentuckyUSA
- Center for Muscle BiologyUniversity of KentuckyLexingtonKentuckyUSA
| | - Jensen Goh
- Department of Physiology, College of MedicineUniversity of KentuckyLexingtonKentuckyUSA
- Center for Muscle BiologyUniversity of KentuckyLexingtonKentuckyUSA
| | - Tolulope P. Saliu
- Department of Physiology, College of MedicineUniversity of KentuckyLexingtonKentuckyUSA
- Center for Muscle BiologyUniversity of KentuckyLexingtonKentuckyUSA
| | - Fatmah Albathi
- Department of Pharmacology and Nutritional Sciences, College of MedicineUniversity of KentuckyLexingtonKentuckyUSA
| | - Allison Owen
- Center for Muscle BiologyUniversity of KentuckyLexingtonKentuckyUSA
- Department of Athletic TrainingCollege of Health SciencesUniversity of KentuckyLexingtonKentuckyUSA
| | - John J. McCarthy
- Department of Physiology, College of MedicineUniversity of KentuckyLexingtonKentuckyUSA
- Center for Muscle BiologyUniversity of KentuckyLexingtonKentuckyUSA
| | - Yuan Wen
- Department of Physiology, College of MedicineUniversity of KentuckyLexingtonKentuckyUSA
- Center for Muscle BiologyUniversity of KentuckyLexingtonKentuckyUSA
- Division of Biomedical Informatics, Department of Internal Medicine, College of MedicineUniversity of KentuckyLexingtonKentuckyUSA
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Warneke K, Lohmann LH, Lima CD, Hollander K, Konrad A, Zech A, Nakamura M, Wirth K, Keiner M, Behm DG. Physiology of Stretch-Mediated Hypertrophy and Strength Increases: A Narrative Review. Sports Med 2023; 53:2055-2075. [PMID: 37556026 PMCID: PMC10587333 DOI: 10.1007/s40279-023-01898-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/22/2023] [Indexed: 08/10/2023]
Abstract
Increasing muscle strength and cross-sectional area is of crucial importance to improve or maintain physical function in musculoskeletal rehabilitation and sports performance. Decreases in muscular performance are experienced in phases of reduced physical activity or immobilization. These decrements highlight the need for alternative, easily accessible training regimens for a sedentary population to improve rehabilitation and injury prevention routines. Commonly, muscle hypertrophy and strength increases are associated with resistance training, typically performed in a training facility. Mechanical tension, which is usually induced with resistance machines and devices, is known to be an important factor that stimulates the underlying signaling pathways to enhance protein synthesis. Findings from animal studies suggest an alternative means to induce mechanical tension to enhance protein synthesis, and therefore muscle hypertrophy by inducing high-volume stretching. Thus, this narrative review discusses mechanical tension-induced physiological adaptations and their impact on muscle hypertrophy and strength gains. Furthermore, research addressing stretch-induced hypertrophy is critically analyzed. Derived from animal research, the stretching literature exploring the impact of static stretching on morphological and functional adaptations was reviewed and critically discussed. No studies have investigated the underlying physiological mechanisms in humans yet, and thus the underlying mechanisms remain speculative and must be discussed in the light of animal research. However, studies that reported functional and morphological increases in humans commonly used stretching durations of > 30 min per session of the plantar flexors, indicating the importance of high stretching volume, if the aim is to increase muscle mass and maximum strength. Therefore, the practical applicability seems limited to settings without access to resistance training (e.g., in an immobilized state at the start of rehabilitation), as resistance training seems to be more time efficient. Nevertheless, further research is needed to generate evidence in different human populations (athletes, sedentary individuals, and rehabilitation patients) and to quantify stretching intensity.
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Affiliation(s)
- Konstantin Warneke
- Institute for Exercise, Sport and Health, Leuphana University, Universitätsallee 1, 21335, Lüneburg, Deutschland, Germany.
- School of Human Kinetics and Recreation, Memorial University of Newfoundland, St. John's, NL, Canada.
- Institute of Sport Science, Alpen-Adria University Klagenfurt, Klagenfurt, Germany.
| | - Lars H Lohmann
- University Sports Center, Carl von Ossietzky University Oldenburg, Oldenburg, Germany
| | - Camila D Lima
- School of Medical and Health Sciences, Edith Cowan University, Joondalup, WA, Australia
| | - Karsten Hollander
- Institute of Interdisciplinary Exercise Science and Sports Medicine, MSH Medical School Hamburg, Hamburg, Germany
| | - Andreas Konrad
- Institute of Human Movement Science, Sport and Health, University of Graz, Graz, Austria
- School of Human Kinetics and Recreation, Memorial University of Newfoundland, St. John's, NL, Canada
| | - Astrid Zech
- Department of Human Motion Science and Exercise Physiology, Friedrich Schiller University, Jena, Germany
| | - Masatoshi Nakamura
- Faculty of Rehabilitation Sciences, Nishi Kyushu University, Ozaki, Kanzaki, Saga, Japan
| | - Klaus Wirth
- Institute of Sport Science, University of Applied Sciences Wiener Neustadt, Wiener Neustadt, Austria
| | - Michael Keiner
- Department of Sport Science, German University of Health and Sport, Ismaning, Germany
| | - David G Behm
- School of Human Kinetics and Recreation, Memorial University of Newfoundland, St. John's, NL, Canada
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Roberts MD, McCarthy JJ, Hornberger TA, Phillips SM, Mackey AL, Nader GA, Boppart MD, Kavazis AN, Reidy PT, Ogasawara R, Libardi CA, Ugrinowitsch C, Booth FW, Esser KA. Mechanisms of mechanical overload-induced skeletal muscle hypertrophy: current understanding and future directions. Physiol Rev 2023; 103:2679-2757. [PMID: 37382939 PMCID: PMC10625844 DOI: 10.1152/physrev.00039.2022] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Revised: 06/12/2023] [Accepted: 06/21/2023] [Indexed: 06/30/2023] Open
Abstract
Mechanisms underlying mechanical overload-induced skeletal muscle hypertrophy have been extensively researched since the landmark report by Morpurgo (1897) of "work-induced hypertrophy" in dogs that were treadmill trained. Much of the preclinical rodent and human resistance training research to date supports that involved mechanisms include enhanced mammalian/mechanistic target of rapamycin complex 1 (mTORC1) signaling, an expansion in translational capacity through ribosome biogenesis, increased satellite cell abundance and myonuclear accretion, and postexercise elevations in muscle protein synthesis rates. However, several lines of past and emerging evidence suggest that additional mechanisms that feed into or are independent of these processes are also involved. This review first provides a historical account of how mechanistic research into skeletal muscle hypertrophy has progressed. A comprehensive list of mechanisms associated with skeletal muscle hypertrophy is then outlined, and areas of disagreement involving these mechanisms are presented. Finally, future research directions involving many of the discussed mechanisms are proposed.
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Affiliation(s)
- Michael D Roberts
- School of Kinesiology, Auburn University, Auburn, Alabama, United States
| | - John J McCarthy
- Department of Physiology, College of Medicine, University of Kentucky, Lexington, Kentucky, United States
| | - Troy A Hornberger
- Department of Comparative Biosciences, University of Wisconsin-Madison, Madison, Wisconsin, United States
| | - Stuart M Phillips
- Department of Kinesiology, McMaster University, Hamilton, Ontario, Canada
| | - Abigail L Mackey
- Institute of Sports Medicine Copenhagen, Department of Orthopedic Surgery, Copenhagen University Hospital-Bispebjerg and Frederiksberg, and Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Gustavo A Nader
- Department of Kinesiology and Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, Pennsylvania, United States
| | - Marni D Boppart
- Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States
| | - Andreas N Kavazis
- School of Kinesiology, Auburn University, Auburn, Alabama, United States
| | - Paul T Reidy
- Department of Kinesiology, Nutrition and Health, Miami University, Oxford, Ohio, United States
| | - Riki Ogasawara
- Healthy Food Science Research Group, Cellular and Molecular Biotechnology Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Japan
| | - Cleiton A Libardi
- MUSCULAB-Laboratory of Neuromuscular Adaptations to Resistance Training, Department of Physical Education, Federal University of São Carlos, São Carlos, Brazil
| | - Carlos Ugrinowitsch
- School of Physical Education and Sport, University of São Paulo, São Paulo, Brazil
| | - Frank W Booth
- Department of Biomedical Sciences, University of Missouri, Columbia, Missouri, United States
| | - Karyn A Esser
- Department of Physiology and Aging, College of Medicine, University of Florida, Gainesville, Florida, United States
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Chen X, Ji Y, Liu R, Zhu X, Wang K, Yang X, Liu B, Gao Z, Huang Y, Shen Y, Liu H, Sun H. Mitochondrial dysfunction: roles in skeletal muscle atrophy. J Transl Med 2023; 21:503. [PMID: 37495991 PMCID: PMC10373380 DOI: 10.1186/s12967-023-04369-z] [Citation(s) in RCA: 23] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Accepted: 07/18/2023] [Indexed: 07/28/2023] Open
Abstract
Mitochondria play important roles in maintaining cellular homeostasis and skeletal muscle health, and damage to mitochondria can lead to a series of pathophysiological changes. Mitochondrial dysfunction can lead to skeletal muscle atrophy, and its molecular mechanism leading to skeletal muscle atrophy is complex. Understanding the pathogenesis of mitochondrial dysfunction is useful for the prevention and treatment of skeletal muscle atrophy, and finding drugs and methods to target and modulate mitochondrial function are urgent tasks in the prevention and treatment of skeletal muscle atrophy. In this review, we first discussed the roles of normal mitochondria in skeletal muscle. Importantly, we described the effect of mitochondrial dysfunction on skeletal muscle atrophy and the molecular mechanisms involved. Furthermore, the regulatory roles of different signaling pathways (AMPK-SIRT1-PGC-1α, IGF-1-PI3K-Akt-mTOR, FoxOs, JAK-STAT3, TGF-β-Smad2/3 and NF-κB pathways, etc.) and the roles of mitochondrial factors were investigated in mitochondrial dysfunction. Next, we analyzed the manifestations of mitochondrial dysfunction in muscle atrophy caused by different diseases. Finally, we summarized the preventive and therapeutic effects of targeted regulation of mitochondrial function on skeletal muscle atrophy, including drug therapy, exercise and diet, gene therapy, stem cell therapy and physical therapy. This review is of great significance for the holistic understanding of the important role of mitochondria in skeletal muscle, which is helpful for researchers to further understanding the molecular regulatory mechanism of skeletal muscle atrophy, and has an important inspiring role for the development of therapeutic strategies for muscle atrophy targeting mitochondria in the future.
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Affiliation(s)
- Xin Chen
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-Innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Department of Neurology, Affiliated Hospital of Nantong University, Nantong University, Nantong, 226001, Jiangsu, People's Republic of China
| | - Yanan Ji
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-Innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Department of Neurology, Affiliated Hospital of Nantong University, Nantong University, Nantong, 226001, Jiangsu, People's Republic of China
| | - Ruiqi Liu
- Department of Clinical Medicine, Medical College, Nantong University, Nantong, Jiangsu, 226001, People's Republic of China
| | - Xucheng Zhu
- Department of Clinical Medicine, Medical College, Nantong University, Nantong, Jiangsu, 226001, People's Republic of China
| | - Kexin Wang
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-Innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Department of Neurology, Affiliated Hospital of Nantong University, Nantong University, Nantong, 226001, Jiangsu, People's Republic of China
| | - Xiaoming Yang
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-Innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Department of Neurology, Affiliated Hospital of Nantong University, Nantong University, Nantong, 226001, Jiangsu, People's Republic of China
| | - Boya Liu
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-Innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Department of Neurology, Affiliated Hospital of Nantong University, Nantong University, Nantong, 226001, Jiangsu, People's Republic of China
| | - Zihui Gao
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-Innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Department of Neurology, Affiliated Hospital of Nantong University, Nantong University, Nantong, 226001, Jiangsu, People's Republic of China
| | - Yan Huang
- Department of Clinical Medicine, Medical College, Nantong University, Nantong, Jiangsu, 226001, People's Republic of China
| | - Yuntian Shen
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-Innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Department of Neurology, Affiliated Hospital of Nantong University, Nantong University, Nantong, 226001, Jiangsu, People's Republic of China.
| | - Hua Liu
- Department of Orthopedics, Haian Hospital of Traditional Chinese Medicine, 55 Ninghai Middle Road, Nantong, Jiangsu, 226600, People's Republic of China.
| | - Hualin Sun
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-Innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Department of Neurology, Affiliated Hospital of Nantong University, Nantong University, Nantong, 226001, Jiangsu, People's Republic of China.
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8
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Uemichi K, Shirai T, Takemasa T. Combined effects of functional overload and denervation on skeletal muscle mass and its regulatory proteins in mice. Physiol Rep 2023; 11:e15689. [PMID: 37161590 PMCID: PMC10169777 DOI: 10.14814/phy2.15689] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Revised: 03/29/2023] [Accepted: 03/31/2023] [Indexed: 05/11/2023] Open
Abstract
Skeletal muscle is a highly pliable tissue and various adaptations such as muscle hypertrophy or atrophy are induced by overloading or disuse, respectively. However, the combined effect of overloading and disuse on the quantitative adaptation of skeletal muscle is unknown. Thus, the aim of this study was to investigate the effects of the combined stimuli of overloading and disuse on mouse skeletal muscle mass and the expression of regulatory factors for muscle protein anabolism or catabolism. Male mice from the Institute Cancer Research were subjected to denervation concomitant with unilateral functional overload or functional overload concomitant with unilateral denervation. Disuse and functional overload were induced by sciatic nerve transection (denervation) and synergist ablation, respectively, and the plantaris muscle was harvested 14 days after the operation. Our results showed that denervation attenuated functional overload-induced muscle hypertrophy and functional overload partially ameliorated the denervation-induced muscle atrophy. P70S6K phosphorylation, an indicator of mechanistic target of rapamycin complex 1 (mTORC1) activation, was not increased by unilateral functional overload in denervated muscles or by unilateral denervation in functional overloaded muscles. Denervation did not affect the increase of LC3-II, a marker of autophagy activation, and ubiquitinated protein expression upon unilateral functional overload. Also, functional overload did not affect ubiquitinated protein expression during unilateral denervation. Thus, our findings suggest that functional overload-induced muscle hypertrophy or denervation-induced muscle atrophy was attenuated by the combined stimuli of overload and denervation.
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Affiliation(s)
- Kazuki Uemichi
- Graduate School of Comprehensive Human Sciences, University of Tsukuba, Ibaraki, Japan
| | - Takanaga Shirai
- Faculty of Health and Sport Sciences, University of Tsukuba, Ibaraki, Japan
| | - Tohru Takemasa
- Faculty of Health and Sport Sciences, University of Tsukuba, Ibaraki, Japan
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9
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Uemichi K, Shirai T, Matsuno R, Iwata T, Tanimura R, Takemasa T. The role of the mechanistic target of rapamycin complex 1 in the regulation of mitochondrial adaptation during skeletal muscle atrophy under denervation or calorie restriction in mice. Appl Physiol Nutr Metab 2023; 48:241-255. [PMID: 36786420 DOI: 10.1139/apnm-2022-0336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
Mechanistic target of rapamycin complex 1 (mTORC1) is a protein complex that regulates skeletal muscle protein synthesis and hypertrophy. mTORC1-mediated signaling activities are activated during denervation-induced skeletal muscle atrophy and suppressed during calorie restriction-induced atrophy. Mitochondria control the qualitative plasticity of skeletal muscles primarily through biogenesis, fusion, and fission. We recently showed that mTORC1 activation contributes toward mitochondrial homeostasis. In this study, we examined the role of mTORC1 in mitochondrial adaptation during denervation- or calorie restriction-induced skeletal muscle atrophy. Seven-week-old Institute of Cancer Research mice were subjected to 14 days of denervation or calorie restriction combined with the administration of the mTORC1 inhibitor-"rapamycin". Our results showed that although mTORC1 inhibition did not alter mitochondrial biogenesis, content and enzyme activity, it suppressed the activation of dynamin-related protein 1 (DRP1), a mitochondrial fission-related protein in denervated muscle, and reduced DRP1 expression in calorie-restricted muscle. Furthermore, calorie restriction-induced mitochondrial fragmentation was partially suppressed by mTORC1 inhibition. Taken together, our results indicate that mTORC1 activation upon denervation and inhibition upon calorie restriction contributes to qualitative changes in muscle plasticity by at least partially regulating the mitochondrial fission response.
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Affiliation(s)
- Kazuki Uemichi
- Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, Japan
| | - Takanaga Shirai
- Research Fellow of the Japan Society for the Promotion of Science, Tokyo, Japan.,Faculty of Health and Sports Sciences, University of Tsukuba, Tsukuba, Japan
| | - Ryunosuke Matsuno
- School of Physical Education, Health and Sports Sciences, University of Tsukuba, Tsukuba, Japan.,Terumo Corporation, Tokyo, Japan
| | - Tomohiro Iwata
- Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, Japan
| | - Riku Tanimura
- Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, Japan
| | - Tohru Takemasa
- Faculty of Health and Sports Sciences, University of Tsukuba, Tsukuba, Japan
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10
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Shirai T, Kitaoka Y, Uemichi K, Tokinoya K, Takeda K, Takemasa T. Effects of lactate administration on hypertrophy and mTOR signaling activation in mouse skeletal muscle. Physiol Rep 2022; 10:e15436. [PMID: 35993446 PMCID: PMC9393907 DOI: 10.14814/phy2.15436] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Revised: 05/01/2022] [Accepted: 05/16/2022] [Indexed: 04/12/2023] Open
Abstract
Lactate is a metabolic product of glycolysis and has recently been shown to act as a signaling molecule that induces adaptations in oxidative metabolism. In this study, we investigated whether lactate administration enhanced muscle hypertrophy and protein synthesis responses during resistance exercise in animal models. We used male ICR mice (7-8 weeks old) were used for chronic (mechanical overload induced by synergist ablation: [OL]) and acute (high-intensity muscle contraction by electrical stimulation: [ES]) resistance exercise models. The animals were intraperitoneally administrated a single dose of sodium lactate (1 g/kg of body weight) in the ES study, and once a day for 14 consecutive days in the OL study. Two weeks of mechanical overload increased plantaris muscle wet weight (main effect of OL: p < 0.05) and fiber cross-sectional area (main effect of OL: p < 0.05), but those were not affected by lactate administration. Following the acute resistance exercise by ES, protein synthesis and phosphorylation of p70 S6 kinase and ribosomal protein S6, which are downstream molecules in the anabolic signaling cascade, were increased (main effect of ES: p < 0.05), but lactate administration had no effect. This study demonstrated that exogenous lactate administration has little effect on the muscle hypertrophic response during resistance exercise using acute ES and chronic OL models. Our results do not support the hypothesis that elevated blood lactate concentration induces protein synthesis responses in skeletal muscle.
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Affiliation(s)
- Takanaga Shirai
- Faculty of Health and Sport SciencesUniversity of TsukubaTsukubaIbarakiJapan
- Research Fellow of Japan Society for Promotion ScienceChiyoda‐kuTokyoJapan
| | - Yu Kitaoka
- Department of Human SciencesKanagawa UniversityYokohama‐shiKanagawaJapan
| | - Kazuki Uemichi
- Graduate School of Comprehensive Human SciencesUniversity of TsukubaTsukubaIbarakiJapan
| | - Katsuyuki Tokinoya
- Research Fellow of Japan Society for Promotion ScienceChiyoda‐kuTokyoJapan
- Division of Clinical Medicine, Faculty of MedicineUniversity of TsukubaTsukubaIbarakiJapan
- Department of Health Promotion SciencesGraduate School of Human Health SciencesTokyo Metropolitan UniversityHachiojiTokyoJapan
| | - Kohei Takeda
- School of Political Science and EconomicsMeiji UniversitySuginami‐kuTokyoJapan
| | - Tohru Takemasa
- Faculty of Health and Sport SciencesUniversity of TsukubaTsukubaIbarakiJapan
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11
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Zumbaugh MD, Johnson SE, Shi TH, Gerrard DE. Molecular and biochemical regulation of skeletal muscle metabolism. J Anim Sci 2022; 100:6652332. [PMID: 35908794 PMCID: PMC9339271 DOI: 10.1093/jas/skac035] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Accepted: 02/02/2022] [Indexed: 12/13/2022] Open
Abstract
Skeletal muscle hypertrophy is a culmination of catabolic and anabolic processes that are interwoven into major metabolic pathways, and as such modulation of skeletal muscle metabolism may have implications on animal growth efficiency. Muscle is composed of a heterogeneous population of muscle fibers that can be classified by metabolism (oxidative or glycolytic) and contractile speed (slow or fast). Although slow fibers (type I) rely heavily on oxidative metabolism, presumably to fuel long or continuous bouts of work, fast fibers (type IIa, IIx, and IIb) vary in their metabolic capability and can range from having a high oxidative capacity to a high glycolytic capacity. The plasticity of muscle permits continuous adaptations to changing intrinsic and extrinsic stimuli that can shift the classification of muscle fibers, which has implications on fiber size, nutrient utilization, and protein turnover rate. The purpose of this paper is to summarize the major metabolic pathways in skeletal muscle and the associated regulatory pathways.
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Affiliation(s)
- Morgan D Zumbaugh
- Department of Animal and Poultry Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
| | - Sally E Johnson
- Department of Animal and Poultry Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
| | - Tim H Shi
- Department of Animal and Poultry Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
| | - David E Gerrard
- Department of Animal and Poultry Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
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12
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Shirai T, Uemichi K, Hidaka Y, Kitaoka Y, Takemasa T. Effect of lactate administration on mouse skeletal muscle under calorie restriction. Curr Res Physiol 2021; 4:202-208. [PMID: 34746839 PMCID: PMC8562144 DOI: 10.1016/j.crphys.2021.09.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 08/25/2021] [Accepted: 09/03/2021] [Indexed: 12/18/2022] Open
Abstract
Calorie restriction (CR) involves a reductions of calorie intake without altering the nutritional balance, and has many beneficial effects, such as improving oxidative metabolism and extending lifespan. However, CR decreases in skeletal muscle mass and fat mass in correlation with the reduction in food intake. Lactate is known to have potential as a signaling molecule rather than a metabolite during exercise. In this study, we examined the effects of the combination of caloric restriction and lactate administration on skeletal muscle adaptation in order to elucidate a novel role of lactate. We first demonstrated that daily lactate administration (equivalent to 1 g/kg of body weight) for 2 weeks suppressed CR-induced muscle atrophy by activating mammalian/mechanistic target of rapamycin (mTOR) signaling, a muscle protein synthesis pathway, and inhibited autophagy-induced muscle degradation. Next, we found that lactate administration under calorie restriction enhanced mitochondrial enzyme activity (citrate synthase and succinate dehydrogenase) and the expression of oxidative phosphorylation (OXPHOS) protein expression. Our results suggest that lactate administration under caloric restriction not only suppresses muscle atrophy but also improves mitochondrial function.
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Affiliation(s)
- Takanaga Shirai
- Graduate School of Comprehensive Human Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, 305-8574, Ibaraki, Japan.,Faculty of Health and Sport Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, 305-8577, Ibaraki, Japan.,Research Fellow of Japan Society for Promotion Science, Japan
| | - Kazuki Uemichi
- Graduate School of Comprehensive Human Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, 305-8574, Ibaraki, Japan
| | - Yuki Hidaka
- School of Physical Education, Health and Sport Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, 305-8574, Ibaraki, Japan
| | - Yu Kitaoka
- Department of Human Sciences, Kanagawa University, 3-27-1 Rokkakubashi, Kanagawa-ku, Yokohama-shi, Kanagawa, 221-8686 Japan
| | - Tohru Takemasa
- Faculty of Health and Sport Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, 305-8577, Ibaraki, Japan
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13
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Gombos Z, Koltai E, Torma F, Bakonyi P, Kolonics A, Aczel D, Ditroi T, Nagy P, Kawamura T, Radak Z. Hypertrophy of Rat Skeletal Muscle Is Associated with Increased SIRT1/Akt/mTOR/S6 and Suppressed Sestrin2/SIRT3/FOXO1 Levels. Int J Mol Sci 2021; 22:ijms22147588. [PMID: 34299206 PMCID: PMC8305659 DOI: 10.3390/ijms22147588] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2021] [Revised: 07/12/2021] [Accepted: 07/13/2021] [Indexed: 11/16/2022] Open
Abstract
Despite the intensive investigation of the molecular mechanism of skeletal muscle hypertrophy, the underlying signaling processes are not completely understood. Therefore, we used an overload model, in which the main synergist muscles (gastrocnemius, soleus) of the plantaris muscle were surgically removed, to cause a significant overload in the remaining plantaris muscle of 8-month-old Wistar male rats. SIRT1-associated pro-anabolic, pro-catabolic molecular signaling pathways, NAD and H2S levels of this overload-induced hypertrophy were studied. Fourteen days of overload resulted in a significant 43% (p < 0.01) increase in the mass of plantaris muscle compared to sham operated animals. Cystathionine-β-synthase (CBS) activities and bioavailable H2S levels were not modified by overload. On the other hand, overload-induced hypertrophy of skeletal muscle was associated with increased SIRT1 (p < 0.01), Akt (p < 0.01), mTOR, S6 (p < 0.01) and suppressed sestrin 2 levels (p < 0.01), which are mostly responsible for anabolic signaling. Decreased FOXO1 and SIRT3 signaling (p < 0.01) suggest downregulation of protein breakdown and mitophagy. Decreased levels of NAD+, sestrin2, OGG1 (p < 0.01) indicate that the redox milieu of skeletal muscle after 14 days of overloading is reduced. The present investigation revealed novel cellular interactions that regulate anabolic and catabolic processes in the hypertrophy of skeletal muscle.
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Affiliation(s)
- Zoltan Gombos
- Research Center of Molecular Exercise Science, University of Physical Education, H-1123 Budapest, Hungary; (Z.G.); (E.K.); (F.T.); (P.B.); (A.K.); (D.A.)
| | - Erika Koltai
- Research Center of Molecular Exercise Science, University of Physical Education, H-1123 Budapest, Hungary; (Z.G.); (E.K.); (F.T.); (P.B.); (A.K.); (D.A.)
| | - Ferenc Torma
- Research Center of Molecular Exercise Science, University of Physical Education, H-1123 Budapest, Hungary; (Z.G.); (E.K.); (F.T.); (P.B.); (A.K.); (D.A.)
| | - Peter Bakonyi
- Research Center of Molecular Exercise Science, University of Physical Education, H-1123 Budapest, Hungary; (Z.G.); (E.K.); (F.T.); (P.B.); (A.K.); (D.A.)
| | - Attila Kolonics
- Research Center of Molecular Exercise Science, University of Physical Education, H-1123 Budapest, Hungary; (Z.G.); (E.K.); (F.T.); (P.B.); (A.K.); (D.A.)
| | - Dora Aczel
- Research Center of Molecular Exercise Science, University of Physical Education, H-1123 Budapest, Hungary; (Z.G.); (E.K.); (F.T.); (P.B.); (A.K.); (D.A.)
| | - Tamas Ditroi
- Department of Molecular Immunology and Toxicology, National Institute of Oncology, H-1122 Budapest, Hungary; (T.D.); (P.N.)
| | - Peter Nagy
- Department of Molecular Immunology and Toxicology, National Institute of Oncology, H-1122 Budapest, Hungary; (T.D.); (P.N.)
- Department of Anatomy and Histology, University of Veterinary Medicine, H-1078 Budapest, Hungary
| | - Takuji Kawamura
- Faculty of Sport Sciences, Waseda University, Tokorozawa 2-579-15, Japan;
| | - Zsolt Radak
- Research Center of Molecular Exercise Science, University of Physical Education, H-1123 Budapest, Hungary; (Z.G.); (E.K.); (F.T.); (P.B.); (A.K.); (D.A.)
- Faculty of Sport Sciences, Waseda University, Tokorozawa 2-579-15, Japan;
- Correspondence: ; Tel.: +36-1-3565764; Fax: +36-1-3566337
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