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Godwin JS, Michel JM, Ludlow AT, Frugé AD, Mobley CB, Nader GA, Roberts MD. Relative rDNA copy number is not associated with resistance training-induced skeletal muscle hypertrophy and does not affect myotube anabolism in vitro. Am J Physiol Regul Integr Comp Physiol 2024; 327:R338-R348. [PMID: 39005083 DOI: 10.1152/ajpregu.00131.2024] [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: 05/16/2024] [Revised: 06/18/2024] [Accepted: 07/01/2024] [Indexed: 07/16/2024]
Abstract
Ribosomal DNA (rDNA) copies exist across multiple chromosomes, and interindividual variation in copy number is speculated to influence the hypertrophic response to resistance training. Thus, we examined if rDNA copy number was associated with resistance training-induced skeletal muscle hypertrophy. Participants (n = 53 male, 21 ± 1 yr old; n = 29 female, 21 ± 2 yr old) performed 10-12 wk of full-body resistance training. Hypertrophy outcomes were determined, as was relative rDNA copy number from preintervention vastus lateralis (VL) biopsies. Pre- and postintervention VL biopsy total RNA was assayed in all participants, and mRNA/rRNA markers of ribosome content and biogenesis were also assayed in the 29 female participants before training, 24 h following training bout 1, and in the basal state after 10 wk of training. Across all participants, no significant associations were evident between relative rDNA copy number and training-induced changes in whole body lean mass (r = -0.034, P = 0.764), vastus lateralis thickness (r = 0.093, P = 0.408), mean myofiber cross-sectional area (r = -0.128, P = 0.259), or changes in muscle RNA concentrations (r = 0.026, P = 0.818), and these trends were similar when examining each gender. However, all Pol-I regulon mRNAs as well as 45S pre-rRNA, 28S rRNA, and 18S rRNA increased 24 h following the first training bout in female participants. Follow-up studies using LHCN-M2 myotubes demonstrated that a reduction in relative rDNA copy number induced by bisphenol A did not significantly affect insulin-like-growth factor-induced myotube hypertrophy. These findings suggest that relative rDNA copy number is not associated with myofiber hypertrophy.NEW & NOTEWORTHY We examined ribosomal DNA (rDNA) copy numbers in men and women who resistance trained for 10-12 wk and found no significant associations with skeletal muscle hypertrophy outcomes. These data, along with in vitro data in immortalized human myotubes whereby rDNA copy number was reduced, provide strong evidence that relative rDNA copy number is not associated with anabolism.
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Affiliation(s)
- Joshua S Godwin
- School of Kinesiology, Auburn University, Auburn, Alabama, United States
| | - J Max Michel
- School of Kinesiology, Auburn University, Auburn, Alabama, United States
| | - Andrew T Ludlow
- School of Kinesiology, University of Michigan, Ann Arbor, Michigan, United States
| | - Andrew D Frugé
- School of Kinesiology, Auburn University, Auburn, Alabama, United States
- College of Nursing, Auburn University, Auburn, Alabama, United States
| | - C Brooks Mobley
- School of Kinesiology, Auburn University, Auburn, Alabama, United States
| | - Gustavo A Nader
- Department of Kinesiology and Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, Pennsylvania, United States
| | - Michael D Roberts
- School of Kinesiology, Auburn University, Auburn, Alabama, United States
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2
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Plotkin DL, Mattingly ML, Anglin DA, Michel JM, Godwin JS, McIntosh MC, Kontos NJ, Bergamasco JGA, Scarpelli MC, Angleri V, Taylor LW, Willoughby DS, Mobley CB, Kavazis AN, Ugrinowitsch C, Libardi CA, Roberts MD. Skeletal muscle myosin heavy chain fragmentation as a potential marker of protein degradation in response to resistance training and disuse atrophy. Exp Physiol 2024. [PMID: 39180757 DOI: 10.1113/ep092093] [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: 06/04/2024] [Accepted: 07/23/2024] [Indexed: 08/26/2024]
Abstract
We examined how resistance exercise (RE), cycling exercise and disuse atrophy affect myosin heavy chain (MyHC) protein fragmentation. The 1boutRE study involved younger men (n = 8; 5 ± 2 years of RE experience) performing a lower body RE bout with vastus lateralis (VL) biopsies being obtained prior to and acutely following exercise. With the 10weekRT study, VL biopsies were obtained in 36 younger adults before and 24 h after their first/naïve RE bout. Participants also engaged in 10 weeks of resistance training and donated VL biopsies before and 24 h after their last RE bout. VL biopsies were also examined in an acute cycling study (n = 7) and a study involving 2 weeks of leg immobilization (n = 20). In the 1boutRE study, fragmentation of all MyHC isoforms (MyHCTotal) increased 3 h post-RE (∼200%, P = 0.018) and returned to pre-exercise levels by 6 h post-RE. Interestingly, a greater magnitude increase in MyHC type IIa versus I isoform fragmentation occurred 3 h post-RE (8.6 ± 6.3-fold vs. 2.1 ± 0.7-fold, P = 0.018). In 10weekRT participants, the first/naïve and last RE bouts increased MyHCTotal fragmentation 24 h post-RE (+65% and +36%, P < 0.001); however, the last RE bout response was attenuated compared to the first bout (P = 0.045). Although cycling exercise did not alter MyHCTotal fragmentation, ∼8% VL atrophy with 2 weeks of leg immobilization increased MyHCTotal fragmentation (∼108%, P < 0.001). Mechanistic C2C12 myotube experiments indicated that MyHCTotal fragmentation is likely due to calpain proteases. In summary, RE and disuse atrophy increase MyHC protein fragmentation. Research into how ageing and disease-associated muscle atrophy affect these outcomes is needed. HIGHLIGHTS: What is the central question of this study? How different exercise stressors and disuse affect skeletal muscle myosin heavy chain fragmentation. What is the main finding and its importance? This investigation is the first to demonstrate that resistance exercise and disuse atrophy lead to skeletal muscle myosin heavy chain protein fragmentation in humans. Mechanistic in vitro experiments provide additional evidence that MyHC fragmentation occurs through calpain proteases.
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Affiliation(s)
| | | | - Derick A Anglin
- School of Kinesiology, Auburn University, Auburn, Alabama, USA
| | - J Max Michel
- School of Kinesiology, Auburn University, Auburn, Alabama, USA
| | - Joshua S Godwin
- School of Kinesiology, Auburn University, Auburn, Alabama, USA
| | | | | | - João G A Bergamasco
- MUSCULAB - Laboratory of Neuromuscular Adaptations to Resistance Training, Department of Physical Education, Federal University of São Carlos - UFSCar, São Carlos, SP, Brazil
| | - Maíra C Scarpelli
- MUSCULAB - Laboratory of Neuromuscular Adaptations to Resistance Training, Department of Physical Education, Federal University of São Carlos - UFSCar, São Carlos, SP, Brazil
| | - Vitor Angleri
- MUSCULAB - Laboratory of Neuromuscular Adaptations to Resistance Training, Department of Physical Education, Federal University of São Carlos - UFSCar, São Carlos, SP, Brazil
| | - Lemuel W Taylor
- School of Health Professions, University of Mary Hardin-Baylor, Belton, Texas, USA
| | - Darryn S Willoughby
- School of Health Professions, University of Mary Hardin-Baylor, Belton, Texas, USA
| | - C Brooks Mobley
- School of Kinesiology, Auburn University, Auburn, Alabama, USA
| | | | - Carlos Ugrinowitsch
- School of Physical Education and Sport, University of São Paulo - USP, São Paulo, SP, Brazil
- Department of Health Sciences and Human Performance, The University of Tampa, Tampa, Florida, USA
| | - Cleiton A Libardi
- MUSCULAB - Laboratory of Neuromuscular Adaptations to Resistance Training, Department of Physical Education, Federal University of São Carlos - UFSCar, São Carlos, SP, Brazil
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3
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Furrer R, Handschin C. Molecular aspects of the exercise response and training adaptation in skeletal muscle. Free Radic Biol Med 2024:S0891-5849(24)00572-0. [PMID: 39059515 DOI: 10.1016/j.freeradbiomed.2024.07.026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2024] [Revised: 07/13/2024] [Accepted: 07/21/2024] [Indexed: 07/28/2024]
Abstract
Skeletal muscle plasticity enables an enormous potential to adapt to various internal and external stimuli and perturbations. Most notably, changes in contractile activity evoke a massive remodeling of biochemical, metabolic and force-generating properties. In recent years, a large number of signals, sensors, regulators and effectors have been implicated in these adaptive processes. Nevertheless, our understanding of the molecular underpinnings of training adaptation remains rudimentary. Specifically, the mechanisms that underlie signal integration, output coordination, functional redundancy and other complex traits of muscle adaptation are unknown. In fact, it is even unclear how stimulus-dependent specification is brought about in endurance or resistance exercise. In this review, we will provide an overview on the events that describe the acute perturbations in single endurance and resistance exercise bouts. Furthermore, we will provide insights into the molecular principles of long-term training adaptation. Finally, current gaps in knowledge will be identified, and strategies for a multi-omic and -cellular analyses of the molecular mechanisms of skeletal muscle plasticity that are engaged in individual, acute exercise bouts and chronic training adaptation discussed.
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Affiliation(s)
- Regula Furrer
- Biozentrum, University of Basel, Spitalstrasse 41, 4056 Basel, Switzerland.
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4
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Sharples AP. A multi-epigenomic map of endurance exercise training. Trends Genet 2024:S0168-9525(24)00153-7. [PMID: 39003156 DOI: 10.1016/j.tig.2024.06.005] [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: 06/21/2024] [Accepted: 06/28/2024] [Indexed: 07/15/2024]
Abstract
The Molecular Transducers of Physical Activity Consortium (MoTrPAC) aims to comprehensively map molecular alterations in response to acute exercise and chronic training. In one of a recent series of papers from MoTrPAC, Nair et al. provide the first multi-epigenomic and transcriptomic integration across eight tissues in both sexes following adaptation to endurance exercise training (EET).
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5
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Knowles OE, Soria M, Saner NJ, Trewin AJ, Alexander SE, Roberts SSH, Hiam D, Garnham AP, Drinkwater EJ, Aisbett B, Lamon S. The interactive effect of sustained sleep restriction and resistance exercise on skeletal muscle transcriptomics in young females. Physiol Genomics 2024; 56:506-518. [PMID: 38766755 DOI: 10.1152/physiolgenomics.00010.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Revised: 05/03/2024] [Accepted: 05/09/2024] [Indexed: 05/22/2024] Open
Abstract
Both sleep loss and exercise regulate gene expression in skeletal muscle, yet little is known about how the interaction of these stressors affects the transcriptome. The aim of this study was to investigate the effect of nine nights of sleep restriction (SR), with repeated resistance exercise (REx) sessions, on the skeletal muscle transcriptome of young, trained females. Ten healthy females aged 18-35 yr old undertook a randomized cross-over study of nine nights of SR (5 h time in bed) and normal sleep (NS; ≥7 h time in bed) with a minimum 6-wk washout. Participants completed four REx sessions per condition (days 3, 5, 7, and 9). Muscle biopsies were collected both pre- and post-REx on days 3 and 9. Gene and protein expression were assessed by RNA sequencing and Western blot, respectively. Three or nine nights of SR had no effect on the muscle transcriptome independently of exercise. However, close to 3,000 transcripts were differentially regulated (false discovery rate < 0.05) 48 h after the completion of three resistance exercise sessions in both NS and SR conditions. Only 39% of downregulated genes and 18% of upregulated genes were common between both conditions, indicating a moderating effect of SR on the response to exercise. SR and REx interacted to alter the enrichment of skeletal muscle transcriptomic pathways in young, resistance-trained females. Performing exercise when sleep restricted may not provide the same adaptive response for individuals as if they were fully rested.NEW & NOTEWORTHY This study investigated the effect of nine nights of sleep restriction, with repeated resistance exercise sessions, on the skeletal muscle transcriptome of young, trained females. Sleep restriction and resistance exercise interacted to alter the enrichment of skeletal muscle transcriptomic pathways in young, resistance-trained females. Performing exercise when sleep restricted may not provide the same adaptive response for individuals as if they were fully rested.
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Affiliation(s)
- Olivia E Knowles
- Institute for Physical Activity and Nutrition, School of Exercise and Nutrition Sciences, Deakin University, Geelong, Victoria, Australia
| | - Megan Soria
- School of Life and Environmental Sciences, Deakin University, Geelong, Victoria, Australia
| | - Nicholas J Saner
- Institute for Health and Sport, Victoria University, Melbourne, Victoria, Australia
| | - Adam J Trewin
- Institute for Physical Activity and Nutrition, School of Exercise and Nutrition Sciences, Deakin University, Geelong, Victoria, Australia
| | - Sarah E Alexander
- Cardiometabolic Health and Exercise Physiology, Baker Heart and Diabetes Institute, Melbourne, Victoria, Australia
| | - Spencer S H Roberts
- Institute for Physical Activity and Nutrition, School of Exercise and Nutrition Sciences, Deakin University, Geelong, Victoria, Australia
| | - Danielle Hiam
- Institute for Physical Activity and Nutrition, School of Exercise and Nutrition Sciences, Deakin University, Geelong, Victoria, Australia
| | - Andrew P Garnham
- Institute for Physical Activity and Nutrition, School of Exercise and Nutrition Sciences, Deakin University, Geelong, Victoria, Australia
| | - Eric J Drinkwater
- Institute for Physical Activity and Nutrition, School of Exercise and Nutrition Sciences, Deakin University, Geelong, Victoria, Australia
| | - Brad Aisbett
- Institute for Physical Activity and Nutrition, School of Exercise and Nutrition Sciences, Deakin University, Geelong, Victoria, Australia
| | - Séverine Lamon
- Institute for Physical Activity and Nutrition, School of Exercise and Nutrition Sciences, Deakin University, Geelong, Victoria, Australia
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6
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Nair VD, Pincas H, Smith GR, Zaslavsky E, Ge Y, Amper MAS, Vasoya M, Chikina M, Sun Y, Raja AN, Mao W, Gay NR, Esser KA, Smith KS, Zhao B, Wiel L, Singh A, Lindholm ME, Amar D, Montgomery S, Snyder MP, Walsh MJ, Sealfon SC. Molecular adaptations in response to exercise training are associated with tissue-specific transcriptomic and epigenomic signatures. CELL GENOMICS 2024; 4:100421. [PMID: 38697122 PMCID: PMC11228891 DOI: 10.1016/j.xgen.2023.100421] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 07/07/2023] [Accepted: 09/12/2023] [Indexed: 05/04/2024]
Abstract
Regular exercise has many physical and brain health benefits, yet the molecular mechanisms mediating exercise effects across tissues remain poorly understood. Here we analyzed 400 high-quality DNA methylation, ATAC-seq, and RNA-seq datasets from eight tissues from control and endurance exercise-trained (EET) rats. Integration of baseline datasets mapped the gene location dependence of epigenetic control features and identified differing regulatory landscapes in each tissue. The transcriptional responses to 8 weeks of EET showed little overlap across tissues and predominantly comprised tissue-type enriched genes. We identified sex differences in the transcriptomic and epigenomic changes induced by EET. However, the sex-biased gene responses were linked to shared signaling pathways. We found that many G protein-coupled receptor-encoding genes are regulated by EET, suggesting a role for these receptors in mediating the molecular adaptations to training across tissues. Our findings provide new insights into the mechanisms underlying EET-induced health benefits across organs.
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Affiliation(s)
- Venugopalan D Nair
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.
| | - Hanna Pincas
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Gregory R Smith
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Elena Zaslavsky
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Yongchao Ge
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Mary Anne S Amper
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Mital Vasoya
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Maria Chikina
- Department of Computational and Systems Biology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Yifei Sun
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | | | - Weiguang Mao
- Department of Computational and Systems Biology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Nicole R Gay
- Department of Genetics, Stanford School of Medicine, Stanford, CA 94305, USA
| | - Karyn A Esser
- Department of Physiology and Aging, University of Florida, Gainesville, FL 32610, USA
| | - Kevin S Smith
- Departments of Pathology and Genetics, Stanford School of Medicine, Stanford, CA 94305, USA
| | - Bingqing Zhao
- Department of Genetics, Stanford School of Medicine, Stanford, CA 94305, USA
| | - Laurens Wiel
- Department of Medicine, Stanford School of Medicine, Stanford, CA 94305, USA
| | - Aditya Singh
- Department of Medicine, Stanford School of Medicine, Stanford, CA 94305, USA
| | - Malene E Lindholm
- Department of Medicine, Stanford School of Medicine, Stanford, CA 94305, USA
| | - David Amar
- Department of Medicine, Stanford School of Medicine, Stanford, CA 94305, USA
| | - Stephen Montgomery
- Departments of Pathology and Genetics, Stanford School of Medicine, Stanford, CA 94305, USA
| | - Michael P Snyder
- Department of Genetics, Stanford School of Medicine, Stanford, CA 94305, USA
| | - Martin J Walsh
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Stuart C Sealfon
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.
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7
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Bittel AJ, Chen YW. DNA Methylation in the Adaptive Response to Exercise. Sports Med 2024; 54:1419-1458. [PMID: 38561436 DOI: 10.1007/s40279-024-02011-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/23/2024] [Indexed: 04/04/2024]
Abstract
Emerging evidence published over the past decade has highlighted the role of DNA methylation in skeletal muscle function and health, including as an epigenetic transducer of the adaptive response to exercise. In this review, we aim to synthesize the latest findings in this field to highlight: (1) the shifting understanding of the genomic localization of altered DNA methylation in response to acute and chronic aerobic and resistance exercise in skeletal muscle (e.g., promoter, gene bodies, enhancers, intergenic regions, un-annotated regions, and genome-wide methylation); (2) how these global/regional methylation changes relate to transcriptional activity following exercise; and (3) the factors (e.g., individual demographic or genetic features, dietary, training history, exercise parameters, local epigenetic characteristics, circulating hormones) demonstrated to alter both the pattern of DNA methylation after exercise, and the relationship between DNA methylation and gene expression. Finally, we discuss the changes in non-CpG methylation and 5-hydroxymethylation after exercise, as well as the importance of emerging single-cell analyses to future studies-areas of increasing focus in the field of epigenetics. We anticipate that this review will help generate a framework for clinicians and researchers to begin developing and testing exercise interventions designed to generate targeted changes in DNA methylation as part of a personalized exercise regimen.
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Affiliation(s)
- Adam J Bittel
- Research Center for Genetic Medicine, Children's National Hospital, 111 Michigan Ave NW, Washington, DC, 20010, USA.
| | - Yi-Wen Chen
- Research Center for Genetic Medicine, Children's National Hospital, 111 Michigan Ave NW, Washington, DC, 20010, USA
- Department of Genomics and Precision Medicine, The George Washington University School of Medicine and Health Science, 111 Michigan Ave NW, Washington, DC, 20010, USA
- Department of Integrative Systems Biology, Institute for Biomedical Sciences, The George Washington University, 2121 I St NW, Washington, DC, 20052, USA
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8
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Plotkin DL, Mattingly ML, Anglin DA, Michel JM, Godwin JS, McIntosh MC, Bergamasco JGA, Scarpelli MC, Angleri V, Taylor LW, Willoughby DS, Mobley CB, Kavazis AN, Ugrinowitsch C, Libardi CA, Roberts MD. Skeletal muscle myosin heavy chain protein fragmentation as a potential marker of protein degradation in response to resistance training and disuse atrophy. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.24.595789. [PMID: 38826385 PMCID: PMC11142278 DOI: 10.1101/2024.05.24.595789] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2024]
Abstract
We sought to examine how resistance exercise (RE), cycling exercise, and disuse atrophy affect myosin heavy chain (MyHC) protein fragmentation in humans. In the first study (1boutRE), younger adult men (n=8; 5±2 years of RE experience) performed a lower body RE bout with vastus lateralis (VL) biopsies obtained immediately before, 3-, and 6-hours post-exercise. In the second study (10weekRT), VL biopsies were obtained in untrained younger adults (n=36, 18 men and 18 women) before and 24 hours (24h) after their first/naïve RE bout. These participants also engaged in 10 weeks (24 sessions) of resistance training and donated VL biopsies before and 24h after their last RE bout. VL biopsies were also examined from a third acute cycling study (n=7) and a fourth study involving two weeks of leg immobilization (n=20, 15 men and 5 women) to determine how MyHC fragmentation was affected. In the 1boutRE study, the fragmentation of all MyHC isoforms (MyHCTotal) increased 3 hours post-RE (~ +200%, p=0.018) and returned to pre-exercise levels by 6 hours post-RE. Immunoprecipitation of MyHCTotal revealed ubiquitination levels remained unaffected at the 3- and 6-hour post-RE time points. Interestingly, a greater increase in magnitude for MyHC type IIa versus I isoform fragmentation occurred 3-hours post-RE (8.6±6.3-fold versus 2.1±0.7-fold, p=0.018). In all 10weekRT participants, the first/naïve and last RE bouts increased MyHCTotal fragmentation 24h post-RE (+65% and +36%, respectively; p<0.001); however, the last RE bout response was attenuated compared to the first bout (p=0.045). The first/naïve bout response was significantly elevated in females only (p<0.001), albeit females also demonstrated a last bout attenuation response (p=0.002). Although an acute cycling bout did not alter MyHCTotal fragmentation, ~8% VL atrophy with two weeks of leg immobilization led to robust MyHCTotal fragmentation (+108%, p<0.001), and no sex-based differences were observed. In summary, RE and disuse atrophy increase MyHC protein fragmentation. A dampened response with 10 weeks of resistance training, and more refined responses in well-trained men, suggest this is an adaptive process. Given the null polyubiquitination IP findings, more research is needed to determine how MyHC fragments are processed. Moreover, further research is needed to determine how aging and disease-associated muscle atrophy affect these outcomes, and whether MyHC fragmentation is a viable surrogate for muscle protein turnover rates.
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Affiliation(s)
| | | | | | - J. Max Michel
- School of Kinesiology, Auburn University, Auburn, Alabama, USA
| | | | | | - João G. A. Bergamasco
- MUSCULAB – Laboratory of Neuromuscular Adaptations to Resistance Training, Department of Physical Education, Federal University of São Carlos – UFSCar, São Carlos, SP, Brazil
| | - Maíra C. Scarpelli
- MUSCULAB – Laboratory of Neuromuscular Adaptations to Resistance Training, Department of Physical Education, Federal University of São Carlos – UFSCar, São Carlos, SP, Brazil
| | - Vitor Angleri
- MUSCULAB – Laboratory of Neuromuscular Adaptations to Resistance Training, Department of Physical Education, Federal University of São Carlos – UFSCar, São Carlos, SP, Brazil
| | - Lemuel W. Taylor
- School of Health Professions, University of Mary Hardin-Baylor, Belton, Texas, USA
| | - Darryn S. Willoughby
- School of Health Professions, University of Mary Hardin-Baylor, Belton, Texas, USA
| | | | | | - Carlos Ugrinowitsch
- School of Physical Education and Sport, University of São Paulo – USP, São Paulo, SP, Brazil
- Department of Health Sciences and Human Performance, The University of Tampa, Tampa, FL, USA
| | - Cleiton A. Libardi
- MUSCULAB – Laboratory of Neuromuscular Adaptations to Resistance Training, Department of Physical Education, Federal University of São Carlos – UFSCar, São Carlos, SP, Brazil
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9
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Li J, Zhang Z, Bo H, Zhang Y. Exercise couples mitochondrial function with skeletal muscle fiber type via ROS-mediated epigenetic modification. Free Radic Biol Med 2024; 213:409-425. [PMID: 38295887 DOI: 10.1016/j.freeradbiomed.2024.01.036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Revised: 01/15/2024] [Accepted: 01/21/2024] [Indexed: 02/04/2024]
Abstract
Skeletal muscle is a heterogeneous tissue composed of different types of muscle fibers, demonstrating substantial plasticity. Physiological or pathological stimuli can induce transitions in muscle fiber types. However, the precise regulatory mechanisms behind these transitions remains unclear. This paper reviews the classification and characteristics of muscle fibers, along with the classical mechanisms of muscle fiber type transitions. Additionally, the role of exercise-induced muscle fiber type transitions in disease intervention is reviewed. Epigenetic pathways mediate cellular adaptations and thus represent potential targets for regulating muscle fiber type transitions. This paper focuses on the mechanisms by which epigenetic modifications couple mitochondrial function and contraction characteristics. Reactive Oxygen Species (ROS) are critical signaling regulators for the health-promoting effects of exercise. Finally, we discuss the role of exercise-induced ROS in regulating epigenetic modifications and the transition of muscle fiber types.
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Affiliation(s)
- Jialin Li
- Tianjin Key Laboratory of Exercise Physiology and Sports Medicine, Institute of Exercise and Health, Tianjin University of Sport, Tianjin, 301617, China
| | - Ziyi Zhang
- Tianjin Key Laboratory of Exercise Physiology and Sports Medicine, Institute of Exercise and Health, Tianjin University of Sport, Tianjin, 301617, China.
| | - Hai Bo
- Department of Military Training Medicines, Logistics University of Chinese People's Armed Police Force, Tianjin, 300162, China.
| | - Yong Zhang
- Tianjin Key Laboratory of Exercise Physiology and Sports Medicine, Institute of Exercise and Health, Tianjin University of Sport, Tianjin, 301617, China.
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10
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McIntosh MC, Anglin DA, Robinson AT, Beck DT, Roberts MD. Making the case for resistance training in improving vascular function and skeletal muscle capillarization. Front Physiol 2024; 15:1338507. [PMID: 38405119 PMCID: PMC10884331 DOI: 10.3389/fphys.2024.1338507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Accepted: 01/26/2024] [Indexed: 02/27/2024] Open
Abstract
Through decades of empirical data, it has become evident that resistance training (RT) can improve strength/power and skeletal muscle hypertrophy. Yet, until recently, vascular outcomes have historically been underemphasized in RT studies, which is underscored by several exercise-related reviews supporting the benefits of endurance training on vascular measures. Several lines of evidence suggest large artery diameter and blood flow velocity increase after a single bout of resistance exercise, and these events are mediated by vasoactive substances released from endothelial cells and myofibers (e.g., nitric oxide). Weeks to months of RT can also improve basal limb blood flow and arterial diameter while lowering blood pressure. Although several older investigations suggested RT reduces skeletal muscle capillary density, this is likely due to most of these studies being cross-sectional in nature. Critically, newer evidence from longitudinal studies contradicts these findings, and a growing body of mechanistic rodent and human data suggest skeletal muscle capillarity is related to mechanical overload-induced skeletal muscle hypertrophy. In this review, we will discuss methods used by our laboratories and others to assess large artery size/function and skeletal muscle capillary characteristics. Next, we will discuss data by our groups and others examining large artery and capillary responses to a single bout of resistance exercise and chronic RT paradigms. Finally, we will discuss RT-induced mechanisms associated with acute and chronic vascular outcomes.
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Affiliation(s)
| | - Derick A. Anglin
- School of Kinesiology, Auburn University, Auburn, AL, United States
| | | | - Darren T. Beck
- School of Kinesiology, Auburn University, Auburn, AL, United States
- Edward Via College of Osteopathic Medicine–Auburn Campus, Auburn, AL, United States
| | - Michael D. Roberts
- School of Kinesiology, Auburn University, Auburn, AL, United States
- Edward Via College of Osteopathic Medicine–Auburn Campus, Auburn, AL, United States
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11
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Radak Z, Pan L, Zhou L, Mozaffaritabar S, Gu Y, A Pinho R, Zheng X, Ba X, Boldogh I. Epigenetic and "redoxogenetic" adaptation to physical exercise. Free Radic Biol Med 2024; 210:65-74. [PMID: 37977212 DOI: 10.1016/j.freeradbiomed.2023.11.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Revised: 11/03/2023] [Accepted: 11/10/2023] [Indexed: 11/19/2023]
Abstract
Exercise-induced adaptation is achieved by altering the epigenetic landscape of the entire genome leading to the expression of genes involved in various processes including regulatory, metabolic, adaptive, immune, and myogenic functions. Clinical and experimental data suggest that the methylation pattern/levels of promoter/enhancer is not linearly correlated with gene expression and proteome levels during physical activity implying a level of complexity and interplay with other regulatory modulators. It has been shown that a higher level of physical fitness is associated with a slower DNA methylation-based aging clock. There is strong evidence supporting exercise-induced ROS being a key regulatory mediator through overlapping events, both as signaling entities and through oxidative modifications to various protein mediators and DNA molecules. ROS generated by physical activity shapes epigenome both directly and indirectly, a complexity we are beginning to unravel within the epigenetic arrangement. Oxidative modification of guanine to 8-oxoguanine is a non-genotoxic alteration, does not distort DNA helix and serves as an epigenetic-like mark. The reader and eraser of oxidized guanine is the 8-oxoguanine DNA glycosylase 1, contributing to changes in gene expression. In fact, it can modulate methylation patterns of promoters/enhancers consequently leading to multiple phenotypic changes. Here, we provide evidence and discuss the potential roles of exercise-induced ROS in altering cytosine methylation patterns during muscle adaptation processes.
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Affiliation(s)
- Zsolt Radak
- Research Center for Molecular Exercise Science, Hungarian University of Sport Science, 1123, Budapest, Hungary; Faculty of Sport Sciences, Waseda University, Tokorozawa, 359-1192, Japan.
| | - Lang Pan
- Department of Microbiology and Immunology, University of Texas Medical Branch at Galveston, Galveston, TX77555, USA
| | - Lei Zhou
- Research Center for Molecular Exercise Science, Hungarian University of Sport Science, 1123, Budapest, Hungary
| | - Soroosh Mozaffaritabar
- Research Center for Molecular Exercise Science, Hungarian University of Sport Science, 1123, Budapest, Hungary
| | - Yaodong Gu
- Faculty of Sports Science, Ningbo University, Ningbo, China
| | - Ricardo A Pinho
- Laboratory of Exercise Biochemistry in Health, Graduate Program in Health Sciences, School of Medicine, Pontifícia Universidade Católica do Paraná, Curitiba, Paraná, Brazil
| | - Xu Zheng
- Key Laboratory of Molecular Epigenetics of Ministry of Education, School of Life Science, Northeast Normal University, Changchun, Jilin, China; Department of Microbiology and Immunology, University of Texas Medical Branch at Galveston, Galveston, TX77555, USA
| | - Xueqing Ba
- Key Laboratory of Molecular Epigenetics of Ministry of Education, School of Life Science, Northeast Normal University, Changchun, Jilin, China; Department of Microbiology and Immunology, University of Texas Medical Branch at Galveston, Galveston, TX77555, USA
| | - Istvan Boldogh
- Department of Microbiology and Immunology, University of Texas Medical Branch at Galveston, Galveston, TX77555, USA
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12
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Yoon JH, Kim S. Learning gene networks under SNP perturbation using SNP and allele-specific expression data. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.23.563661. [PMID: 37961468 PMCID: PMC10634764 DOI: 10.1101/2023.10.23.563661] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
Allele-specific expression quantification from RNA-seq reads provides opportunities to study the control of gene regulatory networks by cis-acting and trans-acting genetic variants. Many existing methods performed a single-gene and single-SNP association analysis to identify expression quantitative trait loci (eQTLs), and placed the eQTLs against known gene networks for functional interpretation. Instead, we view eQTL data as a capture of the effects of perturbation of gene regulatory system by a large number of genetic variants and reconstruct a gene network perturbed by eQTLs. We introduce a statistical framework called CiTruss for simultaneously learning a gene network and cis-acting and trans-acting eQTLs that perturb this network, given population allele-specific expression and SNP data. CiTruss uses a multi-level conditional Gaussian graphical model to model trans-acting eQTLs perturbing the expression of both alleles in gene network at the top level and cis-acting eQTLs perturbing the expression of each allele at the bottom level. We derive a transformation of this model that allows efficient learning for large-scale human data. Our analysis of the GTEx and LG×SM advanced intercross line mouse data for multiple tissue types with CiTruss provides new insights into genetics of gene regulation. CiTruss revealed that gene networks consist of local subnetworks over proximally located genes and global subnetworks over genes scattered across genome, and that several aspects of gene regulation by eQTLs such as the impact of genetic diversity, pleiotropy, tissue-specific gene regulation, and local and long-range linkage disequilibrium among eQTLs can be explained through these local and global subnetworks.
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Affiliation(s)
- Jun Ho Yoon
- Computational Biology Department, Carnegie Mellon University, Pittsburgh, PA 15213, United States of America
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13
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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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14
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Mattingly ML, Ruple BA, Sexton CL, Godwin JS, McIntosh MC, Smith MA, Plotkin DL, Michel JM, Anglin DA, Kontos NJ, Fei S, Phillips SM, Mobley CB, Vechetti I, Vann CG, Roberts MD. Resistance training in humans and mechanical overload in rodents do not elevate muscle protein lactylation. Front Physiol 2023; 14:1281702. [PMID: 37841321 PMCID: PMC10569119 DOI: 10.3389/fphys.2023.1281702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Accepted: 09/20/2023] [Indexed: 10/17/2023] Open
Abstract
Although several reports have hypothesized that exercise may increase skeletal muscle protein lactylation, empirical evidence in humans is lacking. Thus, we adopted a multi-faceted approach to examine if acute and subchronic resistance training (RT) altered skeletal muscle protein lactylation levels. In mice, we also sought to examine if surgical ablation-induced plantaris hypertrophy coincided with increases in muscle protein lactylation. To examine acute responses, participants' blood lactate concentrations were assessed before, during, and after eight sets of an exhaustive lower body RT bout (n = 10 trained college-aged men). Vastus lateralis biopsies were also taken before, 3-h post, and 6-h post-exercise to assess muscle protein lactylation. To identify training responses, another cohort of trained college-aged men (n = 14) partook in 6 weeks of lower-body RT (3x/week) and biopsies were obtained before and following the intervention. Five-month-old C57BL/6 mice were subjected to 10 days of plantaris overload (OV, n = 8) or served as age-matched sham surgery controls (Sham, n = 8). Although acute resistance training significantly increased blood lactate responses ∼7.2-fold (p < 0.001), cytoplasmic and nuclear protein lactylation levels were not significantly altered at the post-exercise time points, and no putative lactylation-dependent mRNA was altered following exercise. Six weeks of RT did not alter cytoplasmic protein lactylation (p = 0.800) despite significantly increasing VL muscle size (+3.5%, p = 0.037), and again, no putative lactylation-dependent mRNA was significantly affected by training. Plantaris muscles were larger in OV versus Sham mice (+43.7%, p < 0.001). However, cytoplasmic protein lactylation was similar between groups (p = 0.369), and nuclear protein lactylation was significantly lower in OV versus Sham mice (p < 0.001). The current null findings, along with other recent null findings in the literature, challenge the thesis that lactate has an appreciable role in promoting skeletal muscle hypertrophy.
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Affiliation(s)
| | - Bradley A. Ruple
- School of Kinesiology, Auburn University, Auburn, AL, United States
| | - Casey L. Sexton
- Department of Physiology and Aging, University of Florida, Gainesville, FL, United States
| | - Joshua S. Godwin
- School of Kinesiology, Auburn University, Auburn, AL, United States
| | | | - Morgan A. Smith
- Department of Genetics, Standford University, Stanford, CA, United States
| | | | - J. Max Michel
- School of Kinesiology, Auburn University, Auburn, AL, United States
| | - Derick A. Anglin
- School of Kinesiology, Auburn University, Auburn, AL, United States
| | | | - Shengyi Fei
- Department of Nutrition and Health Sciences, University of Nebraska-Lincoln, Lincoln, NE, United States
| | | | - C. Brooks Mobley
- School of Kinesiology, Auburn University, Auburn, AL, United States
| | - Ivan Vechetti
- Department of Nutrition and Health Sciences, University of Nebraska-Lincoln, Lincoln, NE, United States
| | - Christopher G. Vann
- Duke Molecular Physiology Institute, Duke University School of Medicine, Duke University, Durham, NC, United States
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15
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Smith JAB, Murach KA, Dyar KA, Zierath JR. Exercise metabolism and adaptation in skeletal muscle. Nat Rev Mol Cell Biol 2023; 24:607-632. [PMID: 37225892 PMCID: PMC10527431 DOI: 10.1038/s41580-023-00606-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/30/2023] [Indexed: 05/26/2023]
Abstract
Viewing metabolism through the lens of exercise biology has proven an accessible and practical strategy to gain new insights into local and systemic metabolic regulation. Recent methodological developments have advanced understanding of the central role of skeletal muscle in many exercise-associated health benefits and have uncovered the molecular underpinnings driving adaptive responses to training regimens. In this Review, we provide a contemporary view of the metabolic flexibility and functional plasticity of skeletal muscle in response to exercise. First, we provide background on the macrostructure and ultrastructure of skeletal muscle fibres, highlighting the current understanding of sarcomeric networks and mitochondrial subpopulations. Next, we discuss acute exercise skeletal muscle metabolism and the signalling, transcriptional and epigenetic regulation of adaptations to exercise training. We address knowledge gaps throughout and propose future directions for the field. This Review contextualizes recent research of skeletal muscle exercise metabolism, framing further advances and translation into practice.
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Affiliation(s)
- Jonathon A B Smith
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Kevin A Murach
- Molecular Mass Regulation Laboratory, Exercise Science Research Center, Department of Health, Human Performance and Recreation, University of Arkansas, Fayetteville, AR, USA
| | - Kenneth A Dyar
- Metabolic Physiology, Institute for Diabetes and Cancer, Helmholtz Diabetes Center, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
- German Center for Diabetes Research (DZD), Neuherberg, Germany
| | - Juleen R Zierath
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden.
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
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16
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Reece TM, Godwin JS, Strube MJ, Ciccone AB, Stout KW, Pearson JR, Vopat BG, Gallagher PM, Roberts MD, Herda TJ. Myofiber hypertrophy adaptations following 6 weeks of low-load resistance training with blood flow restriction in untrained males and females. J Appl Physiol (1985) 2023; 134:1240-1255. [PMID: 37022967 PMCID: PMC10190928 DOI: 10.1152/japplphysiol.00704.2022] [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: 11/20/2022] [Revised: 03/30/2023] [Accepted: 03/31/2023] [Indexed: 04/07/2023] Open
Abstract
The effects of low-load resistance training with blood flow restriction (BFR) on hypertrophy of type I/II myofibers remains unclear, especially in females. The purpose of the present study is to examine changes in type I/II myofiber cross-sectional area (fCSA) and muscle CSA (mCSA) of the vastus lateralis (VL) from before (Pre) to after (Post) 6 wk of high-load resistance training (HL; n = 15, 8 females) and low-load resistance training with BFR (n = 16, 8 females). Mixed-effects models were used to analyze fCSA with group (HL, BFR), sex (M, F), fiber type (I, II), and time (Pre, Post) included as factors. mCSA increased from pre- to posttraining (P < 0.001, d = 0.91) and was greater in males compared with females (P < 0.001, d = 2.26). Type II fCSA increased pre- to post-HL (P < 0.05, d = 0.46) and was greater in males compared with females (P < 0.05, d = 0.78). There were no significant increases in fCSA pre- to post-BFR for either fiber type or sex. Cohen's d, however, revealed moderate effect sizes in type I and II fCSA for males (d = 0.59 and 0.67), although this did not hold true for females (d = 0.29 and 0.34). Conversely, the increase in type II fCSA was greater for females than for males after HL. In conclusion, low-load resistance training with BFR may not promote myofiber hypertrophy to the level of HL resistance training, and similar responses were generally observed for males and females. In contrast, comparable effect sizes for mCSA and 1-repetition maximum (1RM) between groups suggest that BFR could play a role in a resistance training program.NEW & NOTEWORTHY This is the first study, to our knowledge, to examine myofiber hypertrophy from low-load resistance training with blood flow restriction (BFR) in females. Although this type of training did not result in myofiber hypertrophy, there were comparable increases in muscle cross-sectional area compared with high-load resistance training. These findings possibly highlight that males and females respond in a similar manner to high-load resistance training and low-load resistance training with BFR.
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Affiliation(s)
- Tanner M Reece
- Program in Physical Therapy, Washington University School of Medicine, St. Louis, Missouri, United States
| | - Joshua S Godwin
- School of Kinesiology, Auburn University, Auburn, Alabama, United States
| | - Michael J Strube
- Department of Psychological and Brain Sciences, Washington University, St. Louis, Missouri, United States
| | - Anthony B Ciccone
- Department of Exercise Science and Outdoor Recreation, Utah Valley University, Orem, Utah, United States
| | - Kevan W Stout
- Department of Health, Sport, and Exercise Sciences, University of Kansas, Lawrence, Kansas, United States
| | - Jeremy R Pearson
- Department of Health, Sport, and Exercise Sciences, University of Kansas, Lawrence, Kansas, United States
| | - Bryan G Vopat
- University of Kansas School of Medicine-Wichita, Wichita, Kansas, United States
| | - Philip M Gallagher
- Department of Health, Sport, and Exercise Sciences, University of Kansas, Lawrence, Kansas, United States
| | - Michael D Roberts
- School of Kinesiology, Auburn University, Auburn, Alabama, United States
| | - Trent J Herda
- Department of Health, Sport, and Exercise Sciences, University of Kansas, Lawrence, Kansas, United States
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17
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McIntosh MC, Sexton CL, Godwin JS, Ruple BA, Michel JM, Plotkin DL, Ziegenfuss TN, Lopez HL, Smith R, Dwaraka VB, Sharples AP, Dalbo VJ, Mobley CB, Vann CG, Roberts MD. Different Resistance Exercise Loading Paradigms Similarly Affect Skeletal Muscle Gene Expression Patterns of Myostatin-Related Targets and mTORC1 Signaling Markers. Cells 2023; 12:898. [PMID: 36980239 PMCID: PMC10047349 DOI: 10.3390/cells12060898] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Revised: 03/10/2023] [Accepted: 03/14/2023] [Indexed: 03/17/2023] Open
Abstract
Although transcriptome profiling has been used in several resistance training studies, the associated analytical approaches seldom provide in-depth information on individual genes linked to skeletal muscle hypertrophy. Therefore, a secondary analysis was performed herein on a muscle transcriptomic dataset we previously published involving trained college-aged men (n = 11) performing two resistance exercise bouts in a randomized and crossover fashion. The lower-load bout (30 Fail) consisted of 8 sets of lower body exercises to volitional fatigue using 30% one-repetition maximum (1 RM) loads, whereas the higher-load bout (80 Fail) consisted of the same exercises using 80% 1 RM loads. Vastus lateralis muscle biopsies were collected prior to (PRE), 3 h, and 6 h after each exercise bout, and 58 genes associated with skeletal muscle hypertrophy were manually interrogated from our prior microarray data. Select targets were further interrogated for associated protein expression and phosphorylation induced-signaling events. Although none of the 58 gene targets demonstrated significant bout x time interactions, ~57% (32 genes) showed a significant main effect of time from PRE to 3 h (15↑ and 17↓, p < 0.01), and ~26% (17 genes) showed a significant main effect of time from PRE to 6 h (8↑ and 9↓, p < 0.01). Notably, genes associated with the myostatin (9 genes) and mammalian target of rapamycin complex 1 (mTORC1) (9 genes) signaling pathways were most represented. Compared to mTORC1 signaling mRNAs, more MSTN signaling-related mRNAs (7 of 9) were altered post-exercise, regardless of the bout, and RHEB was the only mTORC1-associated mRNA that was upregulated following exercise. Phosphorylated (phospho-) p70S6K (Thr389) (p = 0.001; PRE to 3 h) and follistatin protein levels (p = 0.021; PRE to 6 h) increased post-exercise, regardless of the bout, whereas phospho-AKT (Thr389), phospho-mTOR (Ser2448), and myostatin protein levels remained unaltered. These data continue to suggest that performing resistance exercise to volitional fatigue, regardless of load selection, elicits similar transient mRNA and signaling responses in skeletal muscle. Moreover, these data provide further evidence that the transcriptional regulation of myostatin signaling is an involved mechanism in response to resistance exercise.
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Affiliation(s)
| | - Casey L. Sexton
- School of Kinesiology, Auburn University, Auburn, AL 36849, USA
| | | | | | - J. Max Michel
- School of Kinesiology, Auburn University, Auburn, AL 36849, USA
| | | | | | | | | | | | - Adam P. Sharples
- Institute for Physical Performance, Norwegian School of Sport Sciences, 0164 Oslo, Norway
| | - Vincent J. Dalbo
- School of Health, Medical and Applied Sciences, Central Queensland University, Rockhampton 4700, Australia
| | | | - Christopher G. Vann
- Duke Molecular Physiology Institute, Duke University School of Medicine, Durham, NC 03824, USA
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