1
|
Emmert ME, Emmert AS, Goh Q, Cornwall R. Sexual dimorphisms in skeletal muscle: current concepts and research horizons. J Appl Physiol (1985) 2024; 137:274-299. [PMID: 38779763 DOI: 10.1152/japplphysiol.00529.2023] [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: 07/31/2023] [Revised: 05/21/2024] [Accepted: 05/21/2024] [Indexed: 05/25/2024] Open
Abstract
The complex compositional and functional nature of skeletal muscle makes this organ an essential topic of study for biomedical researchers and clinicians. An additional layer of complexity is added with the consideration of sex as a biological variable. Recent research advances have revealed sexual dimorphisms in developmental biology, muscle homeostasis, adaptive responses, and disorders relating to skeletal muscle. Many of the observed sex differences have hormonal and molecular mechanistic underpinnings, whereas others have yet to be elucidated. Future research is needed to investigate the mechanisms dictating sex-based differences in the various aspects of skeletal muscle. As such, it is necessary that skeletal muscle biologists ensure that both female and male subjects are represented in biomedical and clinical studies to facilitate the successful testing and development of therapeutics for all patients.
Collapse
Affiliation(s)
- Marianne E Emmert
- Division of Orthopaedic Surgery, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, United States
| | - Andrew S Emmert
- Department of Orthopaedic Surgery, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States
| | - Qingnian Goh
- Division of Orthopaedic Surgery, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, United States
- Department of Orthopaedic Surgery, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States
| | - Roger Cornwall
- Division of Orthopaedic Surgery, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, United States
- Department of Orthopaedic Surgery, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States
- Division of Developmental Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, United States
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States
| |
Collapse
|
2
|
Beaudry K, De Lisio M. Sex-Based Differences in Muscle Stem Cell Regulation Following Exercise. Exerc Sport Sci Rev 2024; 52:87-94. [PMID: 38445901 DOI: 10.1249/jes.0000000000000337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/07/2024]
Abstract
Sexual dimorphism, driven by the sex hormones testosterone and estrogen, influences body composition, muscle fiber type, and inflammation. Research related to muscle stem cell (MuSC) responses to exercise has mainly focused on males. We propose a novel hypothesis that there are sex-based differences in MuSC regulation following exercise, such that males have more MuSCs, whereas females demonstrate a greater capacity for regeneration.
Collapse
Affiliation(s)
- Kayleigh Beaudry
- School of Human Kinetics , Department of Cellular and Molecular Medicine, Regenerative Medicine Program, Centre on Neuromuscular Disease , University of Ottawa, Ottawa, Ontario, Canada
| | | |
Collapse
|
3
|
Sterczala AJ, Rodriguez‐Ortiz N, Feigel ED, Krajewski K, Martin BJ, Sekel NM, Lovalekar M, Kargl CK, Koltun KJ, Van Eck C, Flanagan S, Connaboy C, Wardle SL, O'Leary TJ, Greeves JP, Nindl BC. Skeletal muscle adaptations to high-intensity, low-volume concurrent resistance and interval training in recreationally active men and women. Physiol Rep 2024; 12:e15953. [PMID: 38490811 PMCID: PMC10942853 DOI: 10.14814/phy2.15953] [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: 11/01/2023] [Revised: 12/16/2023] [Accepted: 12/16/2023] [Indexed: 03/17/2024] Open
Abstract
This study compared the structural and cellular skeletal muscle factors underpinning adaptations in maximal strength, power, aerobic capacity, and lean body mass to a 12-week concurrent resistance and interval training program in men and women. Recreationally active women and men completed three training sessions per week consisting of high-intensity, low-volume resistance training followed by interval training performed using a variety upper and lower body exercises representative of military occupational tasks. Pre- and post-training vastus lateralis muscle biopsies were analyzed for changes in muscle fiber type, cross-sectional area, capillarization, and mitochondrial biogenesis marker content. Changes in maximal strength, aerobic capacity, and lean body mass (LBM) were also assessed. Training elicited hypertrophy of type I (12.9%; p = 0.016) and type IIa (12.7%; p = 0.007) muscle fibers in men only. In both sexes, training decreased type IIx fiber expression (1.9%; p = 0.046) and increased total PGC-1α (29.7%, p < 0.001) and citrate synthase (11.0%; p < 0.014) content, but had no effect on COX IV content or muscle capillarization. In both sexes, training increased maximal strength and LBM but not aerobic capacity. The concurrent training program was effective at increasing strength and LBM but not at improving aerobic capacity or skeletal muscle adaptations underpinning aerobic performance.
Collapse
Affiliation(s)
- Adam J. Sterczala
- Neuromuscular Research Laboratory and Warrior Human Performance Research CenterUniversity of PittsburghPittsburghPennsylvaniaUSA
- Present address:
Human Engineering Research LaboratoriesVA Pittsburgh Healthcare SystemPittsburghPennsylvaniaUSA
| | - Nathaniel Rodriguez‐Ortiz
- Neuromuscular Research Laboratory and Warrior Human Performance Research CenterUniversity of PittsburghPittsburghPennsylvaniaUSA
| | - Evan D. Feigel
- Neuromuscular Research Laboratory and Warrior Human Performance Research CenterUniversity of PittsburghPittsburghPennsylvaniaUSA
| | - Kellen T. Krajewski
- Neuromuscular Research Laboratory and Warrior Human Performance Research CenterUniversity of PittsburghPittsburghPennsylvaniaUSA
| | - Brian J. Martin
- Neuromuscular Research Laboratory and Warrior Human Performance Research CenterUniversity of PittsburghPittsburghPennsylvaniaUSA
| | - Nicole M. Sekel
- Neuromuscular Research Laboratory and Warrior Human Performance Research CenterUniversity of PittsburghPittsburghPennsylvaniaUSA
| | - Mita Lovalekar
- Neuromuscular Research Laboratory and Warrior Human Performance Research CenterUniversity of PittsburghPittsburghPennsylvaniaUSA
| | - Christopher K. Kargl
- Neuromuscular Research Laboratory and Warrior Human Performance Research CenterUniversity of PittsburghPittsburghPennsylvaniaUSA
| | - Kristen J. Koltun
- Neuromuscular Research Laboratory and Warrior Human Performance Research CenterUniversity of PittsburghPittsburghPennsylvaniaUSA
| | - Carola Van Eck
- Department of Orthopaedic SurgeryUniversity of PittsburghPittsburghPennsylvaniaUSA
| | - Shawn D. Flanagan
- Neuromuscular Research Laboratory and Warrior Human Performance Research CenterUniversity of PittsburghPittsburghPennsylvaniaUSA
- Present address:
Center for Lower Extremity Ambulatory ResearchRosalind Franklin University of Medicine & ScienceNorth ChicagoILUSA
| | - Christopher Connaboy
- Neuromuscular Research Laboratory and Warrior Human Performance Research CenterUniversity of PittsburghPittsburghPennsylvaniaUSA
- Present address:
Center for Lower Extremity Ambulatory ResearchRosalind Franklin University of Medicine & ScienceNorth ChicagoILUSA
| | - Sophie L. Wardle
- Army Health and Performance ResearchArmy HeadquartersAndoverUK
- Present address:
Norwich Medical School, Faculty of Medicine and Health SciencesUniversity of East AngliaNorwichUK
| | - Thomas J. O'Leary
- Army Health and Performance ResearchArmy HeadquartersAndoverUK
- Present address:
Norwich Medical School, Faculty of Medicine and Health SciencesUniversity of East AngliaNorwichUK
| | - Julie P. Greeves
- Army Health and Performance ResearchArmy HeadquartersAndoverUK
- Present address:
Norwich Medical School, Faculty of Medicine and Health SciencesUniversity of East AngliaNorwichUK
- Present address:
Division of Surgery and Interventional ScienceUniversity College LondonLondonUK
| | - Bradley C. Nindl
- Neuromuscular Research Laboratory and Warrior Human Performance Research CenterUniversity of PittsburghPittsburghPennsylvaniaUSA
| |
Collapse
|
4
|
Blemker SS, Brooks SV, Esser KA, Saul KR. Fiber-type traps: revisiting common misconceptions about skeletal muscle fiber types with application to motor control, biomechanics, physiology, and biology. J Appl Physiol (1985) 2024; 136:109-121. [PMID: 37994416 PMCID: PMC11212792 DOI: 10.1152/japplphysiol.00337.2023] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Revised: 10/24/2023] [Accepted: 11/13/2023] [Indexed: 11/24/2023] Open
Abstract
Skeletal muscle is a highly complex tissue that is studied by scientists from a wide spectrum of disciplines, including motor control, biomechanics, exercise science, physiology, cell biology, genetics, regenerative medicine, orthopedics, and engineering. Although this diversity in perspectives has led to many important discoveries, historically, there has been limited overlap in discussions across fields. This has led to misconceptions and oversimplifications about muscle biology that can create confusion and potentially slow scientific progress across fields. The purpose of this synthesis paper is to bring together research perspectives across multiple muscle fields to identify common assumptions related to muscle fiber type that are points of concern to clarify. These assumptions include 1) classification by myosin isoform and fiber oxidative capacity is equivalent, 2) fiber cross-sectional area (CSA) is a surrogate marker for myosin isoform or oxidative capacity, and 3) muscle force-generating capacity can be inferred from myosin isoform. We address these three fiber-type traps and provide some context for how these misunderstandings can and do impact experimental design, computational modeling, and interpretations of findings, from the perspective of a range of fields. We stress the dangers of generalizing findings about "muscle fiber types" among muscles or across species or sex, and we note the importance for precise use of common terminology across the muscle fields.
Collapse
Affiliation(s)
- Silvia S Blemker
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia, United States
| | - Susan V Brooks
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan, United States
| | - Karyn A Esser
- Department of Physiology and Aging, University of Florida, Gainesville, Florida, United States
| | - Katherine R Saul
- Department of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, North Carolina, United States
| |
Collapse
|
5
|
Fennel ZJ, Ducharme JB, Berkemeier QN, Specht JW, McKenna ZJ, Simpson SE, Nava RC, Escobar KA, Hafen PS, Deyhle MR, Amorim FT, Mermier CM. Effect of heat stress on heat shock protein expression and hypertrophy-related signaling in the skeletal muscle of trained individuals. Am J Physiol Regul Integr Comp Physiol 2023; 325:R735-R749. [PMID: 37842742 DOI: 10.1152/ajpregu.00031.2023] [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: 01/30/2023] [Revised: 10/04/2023] [Accepted: 10/05/2023] [Indexed: 10/17/2023]
Abstract
Muscle mass is balanced between hypertrophy and atrophy by cellular processes, including activation of the protein kinase B-mechanistic target of rapamycin (Akt-mTOR) signaling cascade. Stressors apart from exercise and nutrition, such as heat stress, can stimulate the heat shock protein A (HSPA) and C (HSPC) families alongside hypertrophic signaling factors and muscle growth. The effects of heat stress on HSP expression and Akt-mTOR activation in human skeletal muscle and their magnitude of activation compared with known hypertrophic stimuli are unclear. Here, we show a single session of whole body heat stress following resistance exercise increases the expression of HSPA and activation of the Akt-mTOR cascade in skeletal muscle compared with resistance exercise in a healthy, resistance-trained population. Heat stress alone may also exert similar effects, though the responses are notably variable and require further investigation. In addition, acute heat stress in C2C12 muscle cells enhanced myotube growth and myogenic fusion, albeit to a lesser degree than growth factor-mediated hypertrophy. Though the mechanisms by which heat stress stimulates hypertrophy-related signaling and the potential mechanistic role of HSPs remain unclear, these findings provide additional evidence implicating heat stress as a novel growth stimulus when combined with resistance exercise in human skeletal muscle and alone in isolated murine muscle cells. We believe these findings will help drive further applied and mechanistic investigation into how heat stress influences muscular hypertrophy and atrophy.NEW & NOTEWORTHY We show that acute resistance exercise followed by whole body heat stress increases the expression of HSPA and increases activation of the Akt-mTOR cascade in a physically active and resistance-trained population.
Collapse
Affiliation(s)
- Zachary J Fennel
- Department of Health, Exercise & Sports Sciences, University of New Mexico, Albuquerque, New Mexico, United States
- Molecular Medicine Program, University of Utah, Salt Lake City, Utah, United States
| | - Jeremy B Ducharme
- Department of Health, Exercise & Sports Sciences, University of New Mexico, Albuquerque, New Mexico, United States
| | - Quint N Berkemeier
- Department of Health, Exercise & Sports Sciences, University of New Mexico, Albuquerque, New Mexico, United States
| | - Jonathan W Specht
- Department of Health, Exercise & Sports Sciences, University of New Mexico, Albuquerque, New Mexico, United States
| | - Zachary J McKenna
- Department of Health, Exercise & Sports Sciences, University of New Mexico, Albuquerque, New Mexico, United States
- Institute for Exercise and Environmental Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, United States
| | - Shandy E Simpson
- Department of Health, Exercise & Sports Sciences, University of New Mexico, Albuquerque, New Mexico, United States
| | - Roberto C Nava
- Fulcrum Therapeutics, Cambridge, Massachusetts, United States
| | - Kurt A Escobar
- Department of Kinesiology, California State University Long Beach, Long Beach, California, United States
| | - Paul S Hafen
- Division of Science, Indiana University Purdue University Columbus, Columbus, Indiana, United States
- Department of Anatomy, Cell Biology, and Physiology, Indiana Center for Musculoskeletal Health, Indiana University School of Medicine Indianapolis, Indianapolis, Indiana, United States
| | - Michael R Deyhle
- Department of Health, Exercise & Sports Sciences, University of New Mexico, Albuquerque, New Mexico, United States
- Department of Cell Biology and Physiology, School of Medicine, University of New Mexico, Albuquerque, New Mexico, United States
| | - Fabiano T Amorim
- Department of Health, Exercise & Sports Sciences, University of New Mexico, Albuquerque, New Mexico, United States
| | - Christine M Mermier
- Department of Health, Exercise & Sports Sciences, University of New Mexico, Albuquerque, New Mexico, United States
| |
Collapse
|
6
|
Jomard C, Gondin J. Influence of sexual dimorphism on satellite cell regulation and inflammatory response during skeletal muscle regeneration. Physiol Rep 2023; 11:e15798. [PMID: 37798097 PMCID: PMC10555529 DOI: 10.14814/phy2.15798] [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: 05/17/2023] [Revised: 08/02/2023] [Accepted: 08/02/2023] [Indexed: 10/07/2023] Open
Abstract
After injury, skeletal muscle regenerates thanks to the key role of satellite cells (SC). The regeneration process is supported and coordinated by other cell types among which immune cells. Among the mechanisms involved in skeletal muscle regeneration, a sexual dimorphism, involving sex hormones and more particularly estrogens, has been suggested. However, the role of sexual dimorphism on skeletal muscle regeneration is not fully understood, likely to the use of various experimental settings in both animals and human. This review aims at addressing how sex and estrogens regulate both the SC and the inflammatory response during skeletal muscle regeneration by considering the different experimental designs used in both animal models (i.e., ovarian hormone deficiency, estrogen replacement or supplementation, treatments with estrogen receptors agonists/antagonists and models knockout for estrogen receptors) and human (hormone therapy replacement, pre vs. postmenopausal, menstrual cycle variation…).
Collapse
Affiliation(s)
- Charline Jomard
- Institut NeuroMyoGène (INMG), Physiopathologie et Génétique du Neurone et du Muscle (PGNM), Université Claude Bernard LyonLyonFrance
| | - Julien Gondin
- Institut NeuroMyoGène (INMG), Physiopathologie et Génétique du Neurone et du Muscle (PGNM), Université Claude Bernard LyonLyonFrance
| |
Collapse
|
7
|
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.
Collapse
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.
| |
Collapse
|