1
|
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.
Collapse
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
| |
Collapse
|
2
|
Wu L, Su C, Yang C, Liu J, Ye Y. TBX3 regulates the transcription of VEGFA to promote osteoblasts proliferation and microvascular regeneration. PeerJ 2022; 10:e13722. [PMID: 35846885 PMCID: PMC9281600 DOI: 10.7717/peerj.13722] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Accepted: 06/22/2022] [Indexed: 01/17/2023] Open
Abstract
Objective Osteochondral decellularization can promote local vascular regeneration, but the exact mechanism is unknown. The aim of this study is to study osteogenic microvascular regeneration in single cells. Methods The scRNA-seq dataset of human periosteal-derived cells (hPDCs) were analyzed by pySCENIC. To examine the role of TBX3 in osteogenesis and vascularization, cell transfection, qRT-PCR, western blot, and CCK-8 cell proliferation assays were performed. Results TCF7L2, TBX3, FLI1, NFKB2, and EZH2 were found to be transcription factors (TFs) most closely associated with corresponding cells. The regulatory network of these TFs was then visualized. Our study knocked down the expression of TBX3 in human osteoblast cell lines. In the TBX3 knockdown group, we observed decreased expression of VEGFA, VEGFB, and VEGFC. Moreover, Western blot analysis showed that downregulating TBX3 resulted in a reduction of VEGFA expression. And TBX3 stimulated osteoblast proliferation in CCK-8 assays. Conclusion TBX3 regulates VEGFA expression and promotes osteoblast proliferation in skeletal microvasculature formation. The findings provide a theoretical basis for investigating the role of TBX3 in promoting local vascular regeneration.
Collapse
Affiliation(s)
- Lichuang Wu
- Department of Trauma/Joint Surgery, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Chenxian Su
- Department of Trauma/Joint Surgery, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Chuanhua Yang
- The Affiliated Hospital of Shandong University of Traditional Chinese Medicine, Shandong, China
| | - Jinxing Liu
- Shanghai ninth people’s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yiheng Ye
- Department of Trauma/Joint Surgery, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| |
Collapse
|
3
|
Dungan CM, Brightwell CR, Wen Y, Zdunek CJ, Latham CM, Thomas NT, Zagzoog AM, Brightwell BD, Nolt GL, Keeble AR, Watowich SJ, Murach KA, Fry CS. Muscle-Specific Cellular and Molecular Adaptations to Late-Life Voluntary Concurrent Exercise. FUNCTION 2022; 3:zqac027. [PMID: 35774589 PMCID: PMC9233305 DOI: 10.1093/function/zqac027] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Revised: 05/06/2022] [Accepted: 05/08/2022] [Indexed: 01/07/2023] Open
Abstract
Murine exercise models can provide information on factors that influence muscle adaptability with aging, but few translatable solutions exist. Progressive weighted wheel running (PoWeR) is a simple, voluntary, low-cost, high-volume endurance/resistance exercise approach for training young mice. In the current investigation, aged mice (22-mo-old) underwent a modified version of PoWeR for 8 wk. Muscle functional, cellular, biochemical, transcriptional, and myonuclear DNA methylation analyses provide an encompassing picture of how muscle from aged mice responds to high-volume combined training. Mice run 6-8 km/d, and relative to sedentary mice, PoWeR increases plantarflexor muscle strength. The oxidative soleus of aged mice responds to PoWeR similarly to young mice in every parameter measured in previous work; this includes muscle mass, glycolytic-to-oxidative fiber type transitioning, fiber size, satellite cell frequency, and myonuclear number. The oxidative/glycolytic plantaris adapts according to fiber type, but with modest overall changes in muscle mass. Capillarity increases markedly with PoWeR in both muscles, which may be permissive for adaptability in advanced age. Comparison to published PoWeR RNA-sequencing data in young mice identified conserved regulators of adaptability across age and muscles; this includes Aldh1l1 which associates with muscle vasculature. Agrn and Samd1 gene expression is upregulated after PoWeR simultaneous with a hypomethylated promoter CpG in myonuclear DNA, which could have implications for innervation and capillarization. A promoter CpG in Rbm10 is hypomethylated by late-life exercise in myonuclei, consistent with findings in muscle tissue. PoWeR and the data herein are a resource for uncovering cellular and molecular regulators of muscle adaptation with aging.
Collapse
Affiliation(s)
- Cory M Dungan
- Department of Physical Therapy, University of Kentucky, Lexington 40536, KY, USA
- Center for Muscle Biology, University of Kentucky, Lexington 40536, KY, USA
| | - Camille R Brightwell
- Center for Muscle Biology, University of Kentucky, Lexington 40536, KY, USA
- Department of Athletic Training and Clinical Nutrition, University of Kentucky, Lexington 40536, KY, USA
| | - Yuan Wen
- Department of Physical Therapy, University of Kentucky, Lexington 40536, KY, USA
- Center for Muscle Biology, University of Kentucky, Lexington 40536, KY, USA
| | | | - Christine M Latham
- Center for Muscle Biology, University of Kentucky, Lexington 40536, KY, USA
- Department of Athletic Training and Clinical Nutrition, University of Kentucky, Lexington 40536, KY, USA
| | - Nicholas T Thomas
- Center for Muscle Biology, University of Kentucky, Lexington 40536, KY, USA
- Department of Athletic Training and Clinical Nutrition, University of Kentucky, Lexington 40536, KY, USA
| | - Alyaa M Zagzoog
- Center for Muscle Biology, University of Kentucky, Lexington 40536, KY, USA
- Department of Athletic Training and Clinical Nutrition, University of Kentucky, Lexington 40536, KY, USA
| | - Benjamin D Brightwell
- Kinesiology and Health Promotion Graduate Program, University of Kentucky, Lexington 40536, KY, USA
| | - Georgia L Nolt
- Center for Muscle Biology, University of Kentucky, Lexington 40536, KY, USA
| | - Alexander R Keeble
- Center for Muscle Biology, University of Kentucky, Lexington 40536, KY, USA
- Department of Athletic Training and Clinical Nutrition, University of Kentucky, Lexington 40536, KY, USA
| | - Stanley J Watowich
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston 77555, TX, USA
| | - Kevin A Murach
- Center for Muscle Biology, University of Kentucky, Lexington 40536, KY, USA
- Department of Health, Human Performance, and Recreation, University of Arkansas, Fayetteville 72701, AR, USA
- Cell and Molecular Biology Program, University of Arkansas, Fayetteville 72701, AR, USA
| | - Christopher S Fry
- Center for Muscle Biology, University of Kentucky, Lexington 40536, KY, USA
- Department of Athletic Training and Clinical Nutrition, University of Kentucky, Lexington 40536, KY, USA
| |
Collapse
|