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Nguyen J, Gilbert PM. Decoding the forces that shape muscle stem cell function. Curr Top Dev Biol 2024; 158:279-306. [PMID: 38670710 DOI: 10.1016/bs.ctdb.2024.02.009] [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] [Indexed: 04/28/2024]
Abstract
Skeletal muscle is a force-producing organ composed of muscle tissues, connective tissues, blood vessels, and nerves, all working in synergy to enable movement and provide support to the body. While robust biomechanical descriptions of skeletal muscle force production at the body or tissue level exist, little is known about force application on microstructures within the muscles, such as cells. Among various cell types, skeletal muscle stem cells reside in the muscle tissue environment and play a crucial role in driving the self-repair process when muscle damage occurs. Early evidence indicates that the fate and function of skeletal muscle stem cells are controlled by both biophysical and biochemical factors in their microenvironments, but much remains to accomplish in quantitatively describing the biophysical muscle stem cell microenvironment. This book chapter aims to review current knowledge on the influence of biophysical stresses and landscape properties on muscle stem cells in heath, aging, and diseases.
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Affiliation(s)
- Jo Nguyen
- Institute of Biomedical Engineering, University of Toronto, Toronto, ON, Canada; Donnelly Centre, University of Toronto, Toronto, ON, Canada
| | - Penney M Gilbert
- Institute of Biomedical Engineering, University of Toronto, Toronto, ON, Canada; Donnelly Centre, University of Toronto, Toronto, ON, Canada; Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada.
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2
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Yoshihara T, Dobashi S, Naito H. Effects of preconditioning with heat stress on acute exercise-induced intracellular signaling in male rat gastrocnemius muscle. Physiol Rep 2024; 12:e15913. [PMID: 38185480 PMCID: PMC10771927 DOI: 10.14814/phy2.15913] [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: 05/25/2023] [Revised: 12/01/2023] [Accepted: 12/01/2023] [Indexed: 01/09/2024] Open
Abstract
Heat stress (HS) induces Akt/mTOR phosphorylation and FoxO3a signaling; however, whether a prior increase in heat shock protein 72 (HSP72) expression affects intracellular signaling following eccentric exercise remains unclear. We analyzed the effects of HS pretreatment on intramuscular signaling in response to acute exercise in 10-week-old male Wistar rats (n = 24). One leg of each rat was exposed to HS and the other served as an internal control (CT). Post-HS, rats were either rested or subjected to downhill treadmill running. Intramuscular signaling responses in the red and white regions of the gastrocnemius muscle were analyzed before, immediately after, or 1 h after exercise (n = 8/group). HS significantly increased HSP72 levels in both deep red and superficial white regions. Although HS did not affect exercise-induced mTOR signaling (S6K1/ERK) responses in the red region, mTOR phosphorylation in the white region was significantly higher in CT legs than in HS legs after exercise. Thr308 phosphorylation of Akt showed region-specific alteration with a decrease in the red region and an increase in the white region immediately after downhill running. Overall, a prior increase in HSP72 expression elicits fiber type-specific changes in exercise-induced Akt and mTOR phosphorylation in rat gastrocnemius muscle.
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Affiliation(s)
| | - Shohei Dobashi
- Graduate School of Health and Sports ScienceJuntendo UniversityChibaJapan
- Institute of Health and Sport SciencesUniversity of TsukubaIbarakiJapan
| | - Hisashi Naito
- Graduate School of Health and Sports ScienceJuntendo UniversityChibaJapan
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3
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Marr KD, Gard JMC, Harryman WL, Keeswood EJ, Paxson AI, Wolgemuth C, Knudsen BS, Nagle RB, Hazlehurst L, Sorbellini M, Cress AE. Biophysical phenotype mixtures reveal advantages for tumor muscle invasion in vivo. Biophys J 2023; 122:4194-4206. [PMID: 37766428 PMCID: PMC10645557 DOI: 10.1016/j.bpj.2023.09.016] [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] [Received: 03/13/2023] [Revised: 08/23/2023] [Accepted: 09/25/2023] [Indexed: 09/29/2023] Open
Abstract
Bladder, colon, gastric, prostate, and uterine cancers originate in organs surrounded by laminin-coated smooth muscle. In human prostate cancer, tumors that are organ confined, without extracapsular extension through muscle, have an overall cancer survival rate of up to 97% compared with 32% for metastatic disease. Our previous work modeling extracapsular extension reported the blocking of tumor invasion by mutation of a laminin-binding integrin called α6β1. Expression of the α6AA mutant resulted in a biophysical switch from cell-ECM (extracellular matrix) to cell-cell adhesion with drug sensitivity properties and an inability to invade muscle. Here we used different admixtures of α6AA and α6WT cells to test the cell heterogeneity requirements for muscle invasion. Time-lapse video microscopy revealed that tumor mixtures self-assembled into invasive networks in vitro, whereas α6AA cells assembled only as cohesive clusters. Invasion of α6AA cells into and through live muscle occurred using a 1:1 mixture of α6AA and α6WT cells. Electric cell-substrate impedance sensing measurements revealed that compared with α6AA cells, invasion-competent α6WT cells were 2.5-fold faster at closing a cell-ECM or cell-cell wound, respectively. Cell-ECM rebuilding kinetics show that an increased response occurred in mixtures since the response was eightfold greater compared with populations containing only one cell type. A synthetic cell adhesion cyclic peptide called MTI-101 completely blocked electric cell-substrate impedance sensing cell-ECM wound recovery that persisted in vitro up to 20 h after the wound. Treatment of tumor-bearing animals with 10 mg/kg MTI-101 weekly resulted in a fourfold decrease of muscle invasion by tumor and a decrease of the depth of invasion into muscle comparable to the α6AA cells. Taken together, these data suggest that mixed biophysical phenotypes of tumor cells within a population can provide functional advantages for tumor invasion into and through muscle that can be potentially inhibited by a synthetic cell adhesion molecule.
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Affiliation(s)
- Kendra D Marr
- Cancer Biology Graduate Interdisciplinary Program, University of Arizona, Tucson, Arizona; Medical Scientist Training Program, College of Medicine, University of Arizona, Tucson, Arizona
| | | | | | - Elijah J Keeswood
- University of Arizona Cancer Center, Tucson, Arizona; Partnership for Native American Cancer Prevention, University of Arizona, Tucson, Arizona
| | - Allan I Paxson
- Partnership for Native American Cancer Prevention, University of Arizona, Tucson, Arizona
| | | | - Beatrice S Knudsen
- Department of Pathology, Huntsman Cancer Institute, University of Utah, Salt Lake City, Utah
| | - Raymond B Nagle
- Department of Pathology, University of Arizona Cancer Center, Tucson, Arizona
| | - Lori Hazlehurst
- Associate Director of Basic Research, Co-Leader Alexander B. Osborn Hematopoietic Malignancy and Transplantation, West Virginia University, Morgantown, West Virginia
| | | | - Anne E Cress
- University of Arizona Cancer Center, Tucson, Arizona; Department of Cellular and Molecular Medicine and Department of Radiation Oncology, College of Medicine, University of Arizona, Tucson, Arizona.
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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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5
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Liu Q, Jin S, Li L, Ayi L, Ding H. Massage protects skeletal muscle from injury during long-term heavy-duty exercise via integrin β1 and laminin 2 channels of basement membrane. BMC Complement Med Ther 2023; 23:266. [PMID: 37495963 PMCID: PMC10369692 DOI: 10.1186/s12906-023-04094-6] [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: 11/27/2022] [Accepted: 07/15/2023] [Indexed: 07/28/2023] Open
Abstract
BACKGROUND Massage is widely used in exercise-induced skeletal muscle damage (EIMD). It has been proven that massage can improve the morphology and function of damaged skeletal muscle in multiple ways. However, whether massage can protect skeletal muscles from injury during long-term heavy-duty exercise has not yet been determined. METHODS In this study, a rat model of overuse injury was established by eccentric running for 4 weeks, and pressing at constant pressure and frequency and massage were used as intervention methods to explore whether massage could protect skeletal muscle from injury through upregulating integrin and the basement membrane laminin. RESULTS The results showed that compared with the model group, the ultrastructure of skeletal muscle in the massage group was relatively complete and clear, and the maximum isotonic and tetanic contraction forces were significantly increased (P < 0.01). In addition, in the massage group, β1 integrin expression was significantly increased, p-FAK protein expression was decreased, and the co-localization of β1 integrin and the basement membrane laminin 2 was significantly increased (P < 0.01). CONCLUSION Our study shows that during long-term heavy-duty exercise, massage can enhance the cell adhesion function mediated by integrin β1 and laminin 2 to protect skeletal muscle from injury and prevent the occurrence of overuse injury.
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Affiliation(s)
- Qingsong Liu
- Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, Chengdu, China
- School of Sports Medicine and Health, Chengdu Sport University, Chengdu, China
| | - Songlin Jin
- School of Sports Medicine and Health, Chengdu Sport University, Chengdu, China
| | - Lunyu Li
- School of Sports Medicine and Health, Chengdu Sport University, Chengdu, China
| | - Liubu Ayi
- School of Sports Medicine and Health, Chengdu Sport University, Chengdu, China
| | - Haili Ding
- Insititute of Sports Medicine and Health, Chengdu Sport University, Chengdu, China.
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Mavropalias G, Boppart M, Usher KM, Grounds MD, Nosaka K, Blazevich AJ. Exercise builds the scaffold of life: muscle extracellular matrix biomarker responses to physical activity, inactivity, and aging. Biol Rev Camb Philos Soc 2023; 98:481-519. [PMID: 36412213 DOI: 10.1111/brv.12916] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 10/23/2022] [Accepted: 10/25/2022] [Indexed: 11/23/2022]
Abstract
Skeletal muscle extracellular matrix (ECM) is critical for muscle force production and the regulation of important physiological processes during growth, regeneration, and remodelling. ECM remodelling is a tightly orchestrated process, sensitive to multi-directional tensile and compressive stresses and damaging stimuli, and its assessment can convey important information on rehabilitation effectiveness, injury, and disease. Despite its profound importance, ECM biomarkers are underused in studies examining the effects of exercise, disuse, or aging on muscle function, growth, and structure. This review examines patterns of short- and long-term changes in the synthesis and concentrations of ECM markers in biofluids and tissues, which may be useful for describing the time course of ECM remodelling following physical activity and disuse. Forces imposed on the ECM during physical activity critically affect cell signalling while disuse causes non-optimal adaptations, including connective tissue proliferation. The goal of this review is to inform researchers, and rehabilitation, medical, and exercise practitioners better about the role of ECM biomarkers in research and clinical environments to accelerate the development of targeted physical activity treatments, improve ECM status assessment, and enhance function in aging, injury, and disease.
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Affiliation(s)
- Georgios Mavropalias
- Centre for Human Performance, School of Medical and Health Sciences, Edith Cowan University, 270 Joondalup Drive, Joondalup, WA, 6027, Australia
- Centre for Molecular Medicine and Innovative Therapeutics, and Centre for Healthy Aging, Health Futures Institute, Murdoch University, Murdoch, WA, 6150, Australia
- Discipline of Exercise Science, Murdoch University, Murdoch, WA, 6150, Australia
| | - Marni Boppart
- Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, 1206 South Fourth St, Urbana, IL, 61801, USA
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana- Champaign, 405 N. Mathews Avenue, Urbana, IL, 61801, USA
| | - Kayley M Usher
- School of Biomedical Sciences, University of Western Australia (M504), 35 Stirling Highway, Crawley, WA, 6009, Australia
| | - Miranda D Grounds
- School of Human Sciences, University of Western Australia, 35 Stirling Highway, Crawley, WA, 6009, Australia
| | - Kazunori Nosaka
- Centre for Human Performance, School of Medical and Health Sciences, Edith Cowan University, 270 Joondalup Drive, Joondalup, WA, 6027, Australia
| | - Anthony J Blazevich
- Centre for Human Performance, School of Medical and Health Sciences, Edith Cowan University, 270 Joondalup Drive, Joondalup, WA, 6027, Australia
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Aujla PK, Hu M, Hartley B, Kranrod JW, Viveiros A, Kilic T, Owen CA, Oudit GY, Seubert JM, Julien O, Kassiri Z. Loss of ADAM15 Exacerbates Transition to Decompensated Myocardial Hypertrophy and Dilation Through Activation of the Calcineurin Pathway. Hypertension 2023; 80:97-110. [PMID: 36330793 DOI: 10.1161/hypertensionaha.122.19411] [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: 11/06/2022]
Abstract
BACKGROUND Myocardial hypertrophy and dilation are key features of cardiomyopathies and involve several cellular and molecular events. ADAMs (a disintegrin and metalloproteinases) are membrane-bound proteinases with diverse functions whose role in heart disease remains underexplored. ADAM15 is expressed in the heart and is downregulated in the failing human heart. We investigated the role ADAM15 in pressure overload cardiomyopathy. METHODS We assessed ADAM15 levels in myocardial specimens from patients. Its direct role in pressure overload was investigated by subjecting wildtype and Adam15-deficient mice to transverse aortic constriction (TAC). RESULTS ADAM15 levels did not change in patients with concentric hypertrophy, but markedly decreased in eccentric hypertrophy and heart failure. Loss of ADAM15 alone did not cause cardiomyopathy in mice (1 year old). After TAC, Adam15-/- mice exhibited worsened eccentric hypertrophy and dilation with greater increase in hypertrophy markers (pJNK, pERK1/2; Nppb, Nppa, Myh7, Acta1) compared with wildtype-TAC. Expression of integrin-α7 (but not integrin β1) increased significantly more in Adam15-/--TAC hearts, while the interaction of these integrins with basement membrane (laminin), decreased consistent with worsened left ventricle dilation. In vitro, ADAM15 knockdown increased cardiomyocyte hypertrophy in response to mechanical stretch. Adam15-/--TAC hearts exhibited increased calcineurin activity and de-phosphorylation of nuclear factor of activated T cells. Calcineurin inhibition (cyclosporin-A) blocked the excess hypertrophy and dilation in Adam15-/--TAC mice. Proteome profiling demonstrated the increased abundance of the key proteins linked to worsened DCM in Adam15-/--TAC. CONCLUSION This is the first report demonstrating that ADAM15 can suppress hypertrophy through regulating the integrin-laminin interaction and the calcineurin pathway.
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Affiliation(s)
- Preetinder K Aujla
- Department of Physiology, Cardiovascular Research Center, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada (P.K.A., M.H., A.V., T.K., G.Y.O., Z.K.)
| | - Mei Hu
- Department of Physiology, Cardiovascular Research Center, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada (P.K.A., M.H., A.V., T.K., G.Y.O., Z.K.)
| | - Bridgette Hartley
- Department of Biochemistry, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada (B.H., O.J.)
| | - Joshua W Kranrod
- Department of Pharmacology, Faculty of Medicine and Dentistry; Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Canada (J.W.K., J.M.S.)
| | - Anissa Viveiros
- Department of Physiology, Cardiovascular Research Center, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada (P.K.A., M.H., A.V., T.K., G.Y.O., Z.K.)
| | - Tolga Kilic
- Department of Physiology, Cardiovascular Research Center, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada (P.K.A., M.H., A.V., T.K., G.Y.O., Z.K.)
| | - Caroline A Owen
- Brigham and Women's Hospital/Harvard Medical School, Boston, MA (C.A.O.)
| | - Gavin Y Oudit
- Department of Physiology, Cardiovascular Research Center, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada (P.K.A., M.H., A.V., T.K., G.Y.O., Z.K.).,Department of Medicine, Cardiovascular Research Center, Division of Cardiology, Mazankowski Alberta Heart Institute, Edmonton, AB, Canada (G.Y.O.)
| | - John M Seubert
- Department of Pharmacology, Faculty of Medicine and Dentistry; Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Canada (J.W.K., J.M.S.)
| | - Olivier Julien
- Department of Biochemistry, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada (B.H., O.J.)
| | - Zamaneh Kassiri
- Department of Physiology, Cardiovascular Research Center, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada (P.K.A., M.H., A.V., T.K., G.Y.O., Z.K.)
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Jacko D, Schaaf K, Masur L, Windoffer H, Aussieker T, Schiffer T, Zacher J, Bloch W, Gehlert S. Repeated and Interrupted Resistance Exercise Induces the Desensitization and Re-Sensitization of mTOR-Related Signaling in Human Skeletal Muscle Fibers. Int J Mol Sci 2022; 23:ijms23105431. [PMID: 35628242 PMCID: PMC9141560 DOI: 10.3390/ijms23105431] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 05/07/2022] [Accepted: 05/09/2022] [Indexed: 02/06/2023] Open
Abstract
The acute resistance exercise (RE)-induced phosphorylation of mTOR-related signaling proteins in skeletal muscle can be blunted after repeated RE. The time frame in which the phosphorylation (p) of mTORS2448, p70S6kT421/S424, and rpS6S235/236 will be reduced during an RE training period in humans and whether progressive (PR) loading can counteract such a decline has not been described. (1) To enclose the time frame in which pmTORS2448, prpS6S235/236, and pp70S6kT421/S424 are acutely reduced after RE occurs during repeated RE. (2) To test whether PR will prevent that reduction compared to constant loading (CO) and (3) whether 10 days without RE may re-increase blunted signaling. Fourteen healthy males (24 ± 2.8 yrs.; 1.83 ± 0.1 cm; 79.3 ± 8.5 kg) were subjected to RE with either PR (n = 8) or CO (n = 6) loading. Subjects performed RE thrice per week, conducting three sets with 10−12 repetitions on a leg press and leg extension machine. Muscle biopsies were collected at rest (T0), 45 min after the first (T1), seventh (T7), 13th (T13), and 14th (X-T14) RE session. No differences were found between PR and CO for any parameter. Thus, the groups were combined, and the results show the merged values. prpS6S235/236 and pp70s6kT421/S424 were increased at T1, but were already reduced at T7 and up to T13 compared to T1. Ten days without RE re-increased prpS6S235/236 and pp70S6kT421/S424 at X-T14 to a level comparable to that of T1. pmTORS2448 was increased from T1 to X-T14 and did not decline over the training period. Single-fiber immunohistochemistry revealed a reduction in prpS6S235/236 in type I fibers from T1 to T13 and a re-increase at X-T14, which was more augmented in type II fibers at T13 (p < 0.05). The entity of myofibers revealed a high heterogeneity in the level of prpS6S235/236, possibly reflecting individual contraction-induced stress during RE. The type I and II myofiber diameter increased from T0 and T1 to T13 and X-T14 (p < 0.05) prpS6S235/236 and pp70s6kT421/S424 reflect RE-induced states of desensitization and re-sensitization in dependency on frequent loading by RE, but also by its cessation.
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Affiliation(s)
- Daniel Jacko
- Department of Molecular and Cellular Sports Medicine, Institute of Cardiovascular Research and Sports Medicine, German Sport University Cologne, 50933 Cologne, Germany; (D.J.); (K.S.); (L.M.); (H.W.); (T.A.); (W.B.)
- Olympic Base Center NRW/Rhineland, 50933 Cologne, Germany
| | - Kirill Schaaf
- Department of Molecular and Cellular Sports Medicine, Institute of Cardiovascular Research and Sports Medicine, German Sport University Cologne, 50933 Cologne, Germany; (D.J.); (K.S.); (L.M.); (H.W.); (T.A.); (W.B.)
| | - Lukas Masur
- Department of Molecular and Cellular Sports Medicine, Institute of Cardiovascular Research and Sports Medicine, German Sport University Cologne, 50933 Cologne, Germany; (D.J.); (K.S.); (L.M.); (H.W.); (T.A.); (W.B.)
| | - Hannes Windoffer
- Department of Molecular and Cellular Sports Medicine, Institute of Cardiovascular Research and Sports Medicine, German Sport University Cologne, 50933 Cologne, Germany; (D.J.); (K.S.); (L.M.); (H.W.); (T.A.); (W.B.)
| | - Thorben Aussieker
- Department of Molecular and Cellular Sports Medicine, Institute of Cardiovascular Research and Sports Medicine, German Sport University Cologne, 50933 Cologne, Germany; (D.J.); (K.S.); (L.M.); (H.W.); (T.A.); (W.B.)
| | - Thorsten Schiffer
- Outpatient Clinic for Sports Traumatology and Public Health Consultation, German Sport University Cologne, 50933 Cologne, Germany;
| | - Jonas Zacher
- Department ofPreventative and Rehabilitative Sports and Performance Medicine, Institute of Cardiology and Sports Medicine, German Sports University Cologne, 50933 Cologne, Germany;
| | - Wilhelm Bloch
- Department of Molecular and Cellular Sports Medicine, Institute of Cardiovascular Research and Sports Medicine, German Sport University Cologne, 50933 Cologne, Germany; (D.J.); (K.S.); (L.M.); (H.W.); (T.A.); (W.B.)
- German Research Centre of Elite Sport (Momentum), German Sport University Cologne, 50933 Cologne, Germany
| | - Sebastian Gehlert
- Department of Molecular and Cellular Sports Medicine, Institute of Cardiovascular Research and Sports Medicine, German Sport University Cologne, 50933 Cologne, Germany; (D.J.); (K.S.); (L.M.); (H.W.); (T.A.); (W.B.)
- Institute of Sport Science, Biosciences of Sports, University of Hildesheim, 31141 Hildesheim, Germany
- Correspondence: ; Tel.: +49-(0)-5121-883-580; Fax: +49-(0)-5121-883-591
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9
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Nestin and osteocrin mRNA increases in human semitendinosus myotendinous junction 7 days after a single bout of eccentric exercise. Histochem Cell Biol 2022; 158:49-64. [DOI: 10.1007/s00418-022-02101-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/20/2022] [Indexed: 11/26/2022]
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10
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Harryman WL, Marr KD, Nagle RB, Cress AE. Integrins and Epithelial-Mesenchymal Cooperation in the Tumor Microenvironment of Muscle-Invasive Lethal Cancers. Front Cell Dev Biol 2022; 10:837585. [PMID: 35300411 PMCID: PMC8921537 DOI: 10.3389/fcell.2022.837585] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Accepted: 02/04/2022] [Indexed: 11/18/2022] Open
Abstract
Muscle-invasive lethal carcinomas traverse into and through this specialized biophysical and growth factor enriched microenvironment. We will highlight cancers that originate in organs surrounded by smooth muscle, which presents a barrier to dissemination, including prostate, bladder, esophageal, gastric, and colorectal cancers. We propose that the heterogeneity of cell-cell and cell-ECM adhesion receptors is an important driver of aggressive tumor networks with functional consequences for progression. Phenotype heterogeneity of the tumor provides a biophysical advantage for tumor network invasion through the tensile muscle and survival of the tumor network. We hypothesize that a functional epithelial-mesenchymal cooperation (EMC)exists within the tumor invasive network to facilitate tumor escape from the primary organ, invasion and traversing of muscle, and navigation to metastatic sites. Cooperation between specific epithelial cells within the tumor and stromal (mesenchymal) cells interacting with the tumor is illustrated using the examples of laminin-binding adhesion molecules—especially integrins—and their response to growth and inflammatory factors in the tumor microenvironment. The cooperation between cell-cell (E-cadherin, CDH1) and cell-ECM (α6 integrin, CD49f) expression and growth factor receptors is highlighted within poorly differentiated human tumors associated with aggressive disease. Cancer-associated fibroblasts are examined for their role in the tumor microenvironment in generating and organizing various growth factors. Cellular structural proteins are potential utility markers for future spatial profiling studies. We also examine the special characteristics of the smooth muscle microenvironment and how invasion by a primary tumor can alter this environment and contribute to tumor escape via cooperation between epithelial and stromal cells. This cooperative state allows the heterogenous tumor clusters to be shaped by various growth factors, co-opt or evade immune system response, adapt from hypoxic to normoxic conditions, adjust to varying energy sources, and survive radiation and chemotherapeutic interventions. Understanding the epithelial-mesenchymal cooperation in early tumor invasive networks holds potential for both identifying early biomarkers of the aggressive transition and identification of novel agents to prevent the epithelial-mesenchymal cooperation phenotype. Epithelial-mesenchymal cooperation is likely to unveil new tumor subtypes to aid in selection of appropriate therapeutic strategies.
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Affiliation(s)
- William L Harryman
- Cancer Biology Graduate Interdisciplinary Program, University of Arizona Cancer Center, Tucson, AZ, United States
| | - Kendra D Marr
- Cancer Biology Graduate Interdisciplinary Program, University of Arizona Cancer Center, Tucson, AZ, United States.,Cancer Biology Graduate Interdisciplinary Program, University of Arizona, Tucson, AZ, United States.,Medical Scientist Training Program, College of Medicine, University of Arizona, Tucson, AZ, United States
| | - Ray B Nagle
- Cancer Biology Graduate Interdisciplinary Program, University of Arizona Cancer Center, Tucson, AZ, United States.,Department of Pathology, College of Medicine, University of Arizona, Tucson, AZ, United States
| | - Anne E Cress
- Cancer Biology Graduate Interdisciplinary Program, University of Arizona Cancer Center, Tucson, AZ, United States.,Department of Cellular and Molecular Medicine and Department of Radiation Oncology, College of Medicine, University of Arizona, Tucson, AZ, United States
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11
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Attwaters M, Hughes SM. Cellular and molecular pathways controlling muscle size in response to exercise. FEBS J 2022; 289:1428-1456. [PMID: 33755332 DOI: 10.1111/febs.15820] [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: 02/02/2021] [Revised: 02/27/2021] [Accepted: 03/12/2021] [Indexed: 12/14/2022]
Abstract
From the discovery of ATP and motor proteins to synaptic neurotransmitters and growth factor control of cell differentiation, skeletal muscle has provided an extreme model system in which to understand aspects of tissue function. Muscle is one of the few tissues that can undergo both increase and decrease in size during everyday life. Muscle size depends on its contractile activity, but the precise cellular and molecular pathway(s) by which the activity stimulus influences muscle size and strength remain unclear. Four correlates of muscle contraction could, in theory, regulate muscle growth: nerve-derived signals, cytoplasmic calcium dynamics, the rate of ATP consumption and physical force. Here, we summarise the evidence for and against each stimulus and what is known or remains unclear concerning their molecular signal transduction pathways and cellular effects. Skeletal muscle can grow in three ways, by generation of new syncytial fibres, addition of nuclei from muscle stem cells to existing fibres or increase in cytoplasmic volume/nucleus. Evidence suggests the latter two processes contribute to exercise-induced growth. Fibre growth requires increase in sarcolemmal surface area and cytoplasmic volume at different rates. It has long been known that high-force exercise is a particularly effective growth stimulus, but how this stimulus is sensed and drives coordinated growth that is appropriately scaled across organelles remains a mystery.
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Affiliation(s)
- Michael Attwaters
- Randall Centre for Cell and Molecular Biophysics, School of Basic and Medical Biosciences, King's College London, UK
| | - Simon M Hughes
- Randall Centre for Cell and Molecular Biophysics, School of Basic and Medical Biosciences, King's College London, UK
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12
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Mavropalias G, Wu YF, Boppart MD, Blazevich AJ, Nosaka K. Increases in Integrin-ILK-RICTOR-Akt Proteins, Muscle Mass, and Strength after Eccentric Cycling Training. Med Sci Sports Exerc 2022; 54:89-97. [PMID: 34468415 PMCID: PMC8921492 DOI: 10.1249/mss.0000000000002778] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
PURPOSE Recently, it has been suggested that a cellular pathway composed of integrin, integrin-linked kinase (ILK), rapamycin-insensitive companion of mTOR (RICTOR), and Akt may facilitate long-term structural and functional adaptations associated with exercise, independent of the mTORC1 pathway. Therefore, we examined changes in integrin-ILK-RICTOR-Akt protein in vastus lateralis (VL) before and after 8 wk of eccentric cycling training (ECC), which was expected to increase muscle function and VL cross-sectional area (CSA). METHODS Eleven men (23 ± 4 yr) completed 24 sessions of ECC with progressive increases in intensity and duration, resulting in a twofold increase in work from the first three (75.4 ± 14.1 kJ) to the last three sessions (150.7 ± 28.4 kJ). Outcome measures included lower limb lean mass, VL CSA, static strength, and peak and average cycling power output. These measures and VL samples were taken before and 4-5 d after the last training session. RESULTS Significant (P < 0.05) increases in integrin-β1 (1.64-fold) and RICTOR (2.99-fold) protein as well as the phosphorylated-to-total ILK ratio (1.70-fold) were found, but integrin-α7 and Akt did not change. Increases in lower limb, thigh, and trunk lean mass (2.8%-5.3%, P < 0.05) and CSA (13.3% ± 9.0%, P < 0.001) were observed. Static strength (18.1% ± 10.8%) and both peak (8.6% ± 10.5%) and average power output (7.4% ± 8.3%) also increased (P < 0.05). However, no significant correlations were found between the magnitude of increases in protein and the magnitude of increases in CSA, static strength, or power output. CONCLUSIONS In addition to increased muscle mass, strength, and power, we demonstrate that ECC increases integrin-β1 and RICTOR total protein and p-ILK/t-ILK, which may play a role in protection against muscle damage as well as anabolic signaling to induce muscle adaptations.
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Affiliation(s)
- Georgios Mavropalias
- Exercise Medicine Research Institute, Edith Cowan University, Australia
- School of Medical and Health Sciences, Edith Cowan University, Australia
| | - Yu-Fu Wu
- Department of Kinesiology & Community Health, University of Illinois at Urbana-Champaign, IL
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, IL
| | - Marni D. Boppart
- Department of Kinesiology & Community Health, University of Illinois at Urbana-Champaign, IL
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, IL
| | | | - Kazunori Nosaka
- Exercise Medicine Research Institute, Edith Cowan University, Australia
- School of Medical and Health Sciences, Edith Cowan University, Australia
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13
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Leser JM, Harriot A, Buck HV, Ward CW, Stains JP. Aging, Osteo-Sarcopenia, and Musculoskeletal Mechano-Transduction. FRONTIERS IN REHABILITATION SCIENCES 2021; 2:782848. [PMID: 36004321 PMCID: PMC9396756 DOI: 10.3389/fresc.2021.782848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Accepted: 11/10/2021] [Indexed: 11/13/2022]
Abstract
The decline in the mass and function of bone and muscle is an inevitable consequence of healthy aging with early onset and accelerated decline in those with chronic disease. Termed osteo-sarcopenia, this condition predisposes the decreased activity, falls, low-energy fractures, and increased risk of co-morbid disease that leads to musculoskeletal frailty. The biology of osteo-sarcopenia is most understood in the context of systemic neuro-endocrine and immune/inflammatory alterations that drive inflammation, oxidative stress, reduced autophagy, and cellular senescence in the bone and muscle. Here we integrate these concepts to our growing understanding of how bone and muscle senses, responds and adapts to mechanical load. We propose that age-related alterations in cytoskeletal mechanics alter load-sensing and mechano-transduction in bone osteocytes and muscle fibers which underscores osteo-sarcopenia. Lastly, we examine the evidence for exercise as an effective countermeasure to osteo-sarcopenia.
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Affiliation(s)
| | | | | | | | - Joseph P. Stains
- Department of Orthopaedics, University of Maryland School of Medicine, Baltimore, MD, United States
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14
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Lagerwaard B, Nieuwenhuizen AG, Bunschoten A, de Boer VC, Keijer J. Matrisome, innervation and oxidative metabolism affected in older compared with younger males with similar physical activity. J Cachexia Sarcopenia Muscle 2021; 12:1214-1231. [PMID: 34219410 PMCID: PMC8517362 DOI: 10.1002/jcsm.12753] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 04/29/2021] [Accepted: 06/08/2021] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Due to the interaction between skeletal muscle ageing and lifestyle factors, it is often challenging to attribute the decline in muscle mass and quality to either changes in lifestyle or to advancing age itself. Because many of the physiological factors affecting muscle mass and quality are modulated by physical activity and physical activity declines with age, the aim of this study is to better understand the effects of early ageing on muscle function by comparing a population of healthy older and young males with similar physical activity patterns. METHODS Eighteen older (69 ± 2.0 years) and 20 young (22 ± 2.0 years) males were recruited based on similar self-reported physical activity, which was verified using accelerometry measurements. Gene expression profiles of vastus lateralis biopsies obtained by RNA sequencing were compared, and key results were validated using quantitative polymerase chain reaction and western blot. RESULTS Total physical activity energy expenditure was similar between the young and old group (404 ± 215 vs. 411 ± 189 kcal/day, P = 0.11). Three thousand seven hundred ninety-seven differentially expressed coding genes (DEGs) were identified (adjusted P-value cut-off of <0.05), of which 1891 were higher and 1906 were lower expressed in the older muscle. The matrisome, innervation and inflammation were the main upregulated processes, and oxidative metabolism was the main downregulated process in old compared with young muscle. Lower protein levels of mitochondrial transcription factor A (TFAM, P = 0.030) and mitochondrial respiratory Complexes IV and II (P = 0.011 and P = 0.0009, respectively) were observed, whereas a trend was observed for Complex I (P = 0.062), in older compared with young muscle. Protein expression of Complexes I and IV was significantly correlated to mitochondrial capacity in the vastus lateralis as measured in vivo (P = 0.017, R2 = 0.42 and P = 0.030, R2 = 0.36). A trend for higher muscle-specific receptor kinase (MUSK) protein levels in the older group was observed (P = 0.08). CONCLUSIONS There are clear differences in the transcriptome signatures of the vastus lateralis muscle of healthy older and young males with similar physical activity levels, including significant differences at the protein level. By disentangling physical activity and ageing, we appoint early skeletal muscle ageing processes that occur despite similar physical activity. Improved understanding of these processes will be key to design targeted anti-ageing therapies.
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Affiliation(s)
- Bart Lagerwaard
- Human and Animal PhysiologyWageningen University and ResearchWageningenThe Netherlands
- TI Food and NutritionWageningenThe Netherlands
| | - Arie G. Nieuwenhuizen
- Human and Animal PhysiologyWageningen University and ResearchWageningenThe Netherlands
| | - Annelies Bunschoten
- Human and Animal PhysiologyWageningen University and ResearchWageningenThe Netherlands
| | - Vincent C.J. de Boer
- Human and Animal PhysiologyWageningen University and ResearchWageningenThe Netherlands
| | - Jaap Keijer
- Human and Animal PhysiologyWageningen University and ResearchWageningenThe Netherlands
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15
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Chowdhury F, Huang B, Wang N. Cytoskeletal prestress: The cellular hallmark in mechanobiology and mechanomedicine. Cytoskeleton (Hoboken) 2021; 78:249-276. [PMID: 33754478 PMCID: PMC8518377 DOI: 10.1002/cm.21658] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 03/16/2021] [Accepted: 03/17/2021] [Indexed: 12/13/2022]
Abstract
Increasing evidence demonstrates that mechanical forces, in addition to soluble molecules, impact cell and tissue functions in physiology and diseases. How living cells integrate mechanical signals to perform appropriate biological functions is an area of intense investigation. Here, we review the evidence of the central role of cytoskeletal prestress in mechanotransduction and mechanobiology. Elevating cytoskeletal prestress increases cell stiffness and reinforces cell stiffening, facilitates long-range cytoplasmic mechanotransduction via integrins, enables direct chromatin stretching and rapid gene expression, spurs embryonic development and stem cell differentiation, and boosts immune cell activation and killing of tumor cells whereas lowering cytoskeletal prestress maintains embryonic stem cell pluripotency, promotes tumorigenesis and metastasis of stem cell-like malignant tumor-repopulating cells, and elevates drug delivery efficiency of soft-tumor-cell-derived microparticles. The overwhelming evidence suggests that the cytoskeletal prestress is the governing principle and the cellular hallmark in mechanobiology. The application of mechanobiology to medicine (mechanomedicine) is rapidly emerging and may help advance human health and improve diagnostics, treatment, and therapeutics of diseases.
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Affiliation(s)
- Farhan Chowdhury
- Department of Mechanical Engineering and Energy ProcessesSouthern Illinois University CarbondaleCarbondaleIllinoisUSA
| | - Bo Huang
- Department of Immunology, Institute of Basic Medical Sciences & State Key Laboratory of Medical Molecular BiologyChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina
| | - Ning Wang
- Department of Mechanical Science and EngineeringUniversity of Illinois at Urbana‐ChampaignUrbanaIllinoisUSA
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16
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Garg K, Mahmassani ZS, Dvoretskiy S, Valero MC, Huntsman HD, Lapp S, Wu YF, Hauschka SD, Burkin DJ, Boppart MD. Laminin-111 Improves the Anabolic Response to Mechanical Load in Aged Skeletal Muscle. J Gerontol A Biol Sci Med Sci 2021; 76:586-590. [PMID: 33284954 DOI: 10.1093/gerona/glaa308] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Indexed: 12/12/2022] Open
Abstract
Anabolic resistance to a mechanical stimulus may contribute to the loss of skeletal muscle mass observed with age. In this study, young and aged mice were injected with saline or human LM-111 (1 mg/kg). One week later, the myotendinous junction of the gastrocnemius muscle was removed via myotenectomy (MTE), thus placing a chronic mechanical stimulus on the remaining plantaris muscle for 2 weeks. LM-111 increased α7B integrin protein expression and clustering of the α7B integrin near DAPI+ nuclei in aged muscle in response to MTE. LM-111 reduced CD11b+ immune cells, enhanced repair, and improved the growth response to loading in aged plantaris muscle. These results suggest that LM-111 may represent a novel therapeutic approach to prevent and/or treat sarcopenia.
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Affiliation(s)
- Koyal Garg
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign
| | - Ziad S Mahmassani
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign.,Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign
| | - Svyatoslav Dvoretskiy
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign.,Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign
| | - M Carmen Valero
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign.,Institute for Genomic Biology, University of Illinois at Urbana-Champaign
| | - Heather D Huntsman
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign.,Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign
| | - Samuel Lapp
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign.,Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign
| | - Yu-Fu Wu
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign.,Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign
| | | | - Dean J Burkin
- Department of Pharmacology, University of Nevada School of Medicine, Reno
| | - Marni D Boppart
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign.,Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign.,Institute for Genomic Biology, University of Illinois at Urbana-Champaign
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17
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Jakobsen JR, Krogsgaard MR. The Myotendinous Junction-A Vulnerable Companion in Sports. A Narrative Review. Front Physiol 2021; 12:635561. [PMID: 33841171 PMCID: PMC8032995 DOI: 10.3389/fphys.2021.635561] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 02/15/2021] [Indexed: 01/17/2023] Open
Abstract
The incidence of strain injuries continues to be high in many popular sports, especially hamstring strain injuries in football, despite a documented important effect of eccentric exercise to prevent strains. Studies investigating the anatomical properties of these injuries in humans are sparse. The majority of strains are seen at the interface between muscle fibers and tendon: the myotendinous junction (MTJ). It has a unique morphology with a highly folded muscle membrane filled with invaginations of collagen fibrils from the tendon, establishing an increased area of force transmission between muscle and tendon. There is a very high rate of remodeling of the muscle cells approaching the MTJ, but little is known about how the tissue adapts to exercise and which structural changes heavy eccentric exercise may introduce. This review summarizes the current knowledge about the anatomy, composition and adaptability of the MTJ, and discusses reasons why strain injuries can be prevented by eccentric exercise.
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Affiliation(s)
- Jens Rithamer Jakobsen
- Section of Sports Traumatology, M51, A Part of IOC Research Center, Bispebjerg and Frederiksberg Hospital, Copenhagen University Hospital, Copenhagen, Denmark
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18
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Gibbs EM, McCourt JL, Shin KM, Hammond KG, Marshall JL, Crosbie RH. Loss of sarcospan exacerbates pathology in mdx mice, but does not affect utrophin amelioration of disease. Hum Mol Genet 2021; 30:149-159. [PMID: 33432327 PMCID: PMC8091037 DOI: 10.1093/hmg/ddaa264] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 10/26/2020] [Accepted: 11/30/2020] [Indexed: 01/02/2023] Open
Abstract
The dystrophin-glycoprotein complex (DGC) is a membrane adhesion complex that provides structural stability at the sarcolemma by linking the myocyte's internal cytoskeleton and external extracellular matrix. In Duchenne muscular dystrophy (DMD), the absence of dystrophin leads to the loss of the DGC at the sarcolemma, resulting in sarcolemmal instability and progressive muscle damage. Utrophin (UTRN), an autosomal homolog of dystrophin, is upregulated in dystrophic muscle and partially compensates for the loss of dystrophin in muscle from patients with DMD. Here, we examine the interaction between Utr and sarcospan (SSPN), a small transmembrane protein that is a core component of both UTRN-glycoprotein complex (UGC) and DGC. We show that additional loss of SSPN causes an earlier onset of disease in dystrophin-deficient mdx mice by reducing the expression of the UGC at the sarcolemma. In order to further evaluate the role of SSPN in maintaining therapeutic levels of Utr at the sarcolemma, we tested the effect of Utr transgenic overexpression in mdx mice lacking SSPN (mdx:SSPN -/-:Utr-Tg). We found that overexpression of Utr restored SSPN to the sarcolemma in mdx muscle but that the ablation of SSPN in mdx muscle reduced Utr at the membrane. Nevertheless, Utr overexpression reduced central nucleation and improved grip strength in both lines. These findings demonstrate that high levels of Utr transgenic overexpression ameliorate the mdx phenotype independently of SSPN expression but that loss of SSPN may impair Utr-based mechanisms that rely on lower levels of Utr protein.
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Affiliation(s)
- Elizabeth M Gibbs
- Department of Integrative Biology and Physiology, University of California, Los Angeles, CA 90095, USA
| | - Jackie L McCourt
- Department of Integrative Biology and Physiology, University of California, Los Angeles, CA 90095, USA
| | - Kara M Shin
- Department of Integrative Biology and Physiology, University of California, Los Angeles, CA 90095, USA
| | - Katherine G Hammond
- Department of Integrative Biology and Physiology, University of California, Los Angeles, CA 90095, USA
| | - Jamie L Marshall
- Department of Integrative Biology and Physiology, University of California, Los Angeles, CA 90095, USA
| | - Rachelle H Crosbie
- Department of Integrative Biology and Physiology, University of California, Los Angeles, CA 90095, USA.,Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA.,Molecular Biology Institute, University of California, Los Angeles, CA, USA
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19
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Cohesive cancer invasion of the biophysical barrier of smooth muscle. Cancer Metastasis Rev 2021; 40:205-219. [PMID: 33398621 DOI: 10.1007/s10555-020-09950-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2020] [Accepted: 12/15/2020] [Indexed: 01/22/2023]
Abstract
Smooth muscle is found around organs in the digestive, respiratory, and reproductive tracts. Cancers arising in the bladder, prostate, stomach, colon, and other sites progress from low-risk disease to high-risk, lethal metastatic disease characterized by tumor invasion into, within, and through the biophysical barrier of smooth muscle. We consider here the unique biophysical properties of smooth muscle and how cohesive clusters of tumor use mechanosensing cell-cell and cell-ECM (extracellular matrix) adhesion receptors to move through a structured muscle and withstand the biophysical forces to reach distant sites. Understanding integrated mechanosensing features within tumor cluster and smooth muscle and potential triggers within adjacent adipose tissue, such as the unique damage-associated molecular pattern protein (DAMP), eNAMPT (extracellular nicotinamide phosphoribosyltransferase), or visfatin, offers an opportunity to prevent the first steps of invasion and metastasis through the structured muscle.
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20
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Corpuz AD, Ramos JW, Matter ML. PTRH2: an adhesion regulated molecular switch at the nexus of life, death, and differentiation. Cell Death Discov 2020; 6:124. [PMID: 33298880 PMCID: PMC7661711 DOI: 10.1038/s41420-020-00357-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 10/02/2020] [Accepted: 10/21/2020] [Indexed: 12/12/2022] Open
Abstract
Peptidyl-tRNA hydrolase 2 (PTRH2; Bit-1; Bit1) is an underappreciated regulator of adhesion signals and Bcl2 expression. Its key roles in muscle differentiation and integrin-mediated signaling are central to the pathology of a recently identified patient syndrome caused by a cluster of Ptrh2 gene mutations. These loss-of-function mutations were identified in patients presenting with severe deleterious phenotypes of the skeletal muscle, endocrine, and nervous systems resulting in a syndrome called Infantile-onset Multisystem Nervous, Endocrine, and Pancreatic Disease (IMNEPD). In contrast, in cancer PTRH2 is a potential oncogene that promotes malignancy and metastasis. PTRH2 modulates PI3K/AKT and ERK signaling in addition to Bcl2 expression and thereby regulates key cellular processes in response to adhesion including cell survival, growth, and differentiation. In this Review, we discuss the state of the science on this important cell survival, anoikis and differentiation regulator, and opportunities for further investigation and translation. We begin with a brief overview of the structure, regulation, and subcellular localization of PTRH2. We discuss the cluster of gene mutations thus far identified which cause developmental delays and multisystem disease. We then discuss the role of PTRH2 and adhesion in breast, lung, and esophageal cancers focusing on signaling pathways involved in cell survival, cell growth, and cell differentiation.
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Affiliation(s)
- Austin D Corpuz
- Cancer Biology Program, University of Hawaii Cancer Center, Honolulu, 96813, HI, USA.,Cell and Molecular Biology Graduate Program, John A. Burns School of Medicine University of Hawaii at Mānoa, Honolulu, HI, 96813, USA
| | - Joe W Ramos
- Cancer Biology Program, University of Hawaii Cancer Center, Honolulu, 96813, HI, USA
| | - Michelle L Matter
- Cancer Biology Program, University of Hawaii Cancer Center, Honolulu, 96813, HI, USA.
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21
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Purslow PP. The Structure and Role of Intramuscular Connective Tissue in Muscle Function. Front Physiol 2020; 11:495. [PMID: 32508678 PMCID: PMC7248366 DOI: 10.3389/fphys.2020.00495] [Citation(s) in RCA: 73] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Accepted: 04/23/2020] [Indexed: 12/12/2022] Open
Abstract
Extracellular matrix (ECM) structures within skeletal muscle play an important, but under-appreciated, role in muscle development, function and adaptation. Each individual muscle is surrounded by epimysial connective tissue and within the muscle there are two distinct extracellular matrix (ECM) structures, the perimysium and endomysium. Together, these three ECM structures make up the intramuscular connective tissue (IMCT). There are large variations in the amount and composition of IMCT between functionally different muscles. Although IMCT acts as a scaffold for muscle fiber development and growth and acts as a carrier for blood vessels and nerves to the muscle cells, the variability in IMCT between different muscles points to a role in the variations in active and passive mechanical properties of muscles. Some traditional measures of the contribution of endomysial IMCT to passive muscle elasticity relied upon tensile measurements on single fiber preparations. These types of measurements may now be thought to be missing the important point that endomysial IMCT networks within a muscle fascicle coordinate forces and displacements between adjacent muscle cells by shear and that active contractile forces can be transmitted by this route (myofascial force transmission). The amount and geometry of the perimysial ECM network separating muscle fascicles varies more between different muscle than does the amount of endomysium. While there is some evidence for myofascial force transmission between fascicles via the perimysium, the variations in this ECM network appears to be linked to the amount of shear displacements between fascicles that must necessarily occur when the whole muscle contracts and changes shape. Fast growth of muscle by fiber hypertrophy is not always associated with a high turnover of ECM components, but slower rates of growth and muscle wasting may be associated with IMCT remodeling. A hypothesis arising from this observation is that the level of cell signaling via shear between integrin and dystroglycan linkages on the surface of the muscle cells and the overlying endomysium may be the controlling factor for IMCT turnover, although this idea is yet to be tested.
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Affiliation(s)
- Peter P Purslow
- Centro de Investigacion Veterinaria de Tandil, Facultad de Ciencias Veterinarias, Universidad Nacional del Centro de la Provincia de Buenos Aires, Tandil, Argentina
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22
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Etienne J, Liu C, Skinner CM, Conboy MJ, Conboy IM. Skeletal muscle as an experimental model of choice to study tissue aging and rejuvenation. Skelet Muscle 2020; 10:4. [PMID: 32033591 PMCID: PMC7007696 DOI: 10.1186/s13395-020-0222-1] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Accepted: 01/12/2020] [Indexed: 12/16/2022] Open
Abstract
Skeletal muscle is among the most age-sensitive tissues in mammal organisms. Significant changes in its resident stem cells (i.e., satellite cells, SCs), differentiated cells (i.e., myofibers), and extracellular matrix cause a decline in tissue homeostasis, function, and regenerative capacity. Based on the conservation of aging across tissues and taking advantage of the relatively well-characterization of the myofibers and associated SCs, skeletal muscle emerged as an experimental system to study the decline in function and maintenance of old tissues and to explore rejuvenation strategies. In this review, we summarize the approaches for understanding the aging process and for assaying the success of rejuvenation that use skeletal muscle as the experimental system of choice. We further discuss (and exemplify with studies of skeletal muscle) how conflicting results might be due to variations in the techniques of stem cell isolation, differences in the assays of functional rejuvenation, or deciding on the numbers of replicates and experimental cohorts.
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Affiliation(s)
- Jessy Etienne
- Department of Bioengineering and QB3 Institute, University of California, Berkeley, Berkeley, CA, 94720-3220, USA
| | - Chao Liu
- Department of Bioengineering and QB3 Institute, University of California, Berkeley, Berkeley, CA, 94720-3220, USA
| | - Colin M Skinner
- Department of Bioengineering and QB3 Institute, University of California, Berkeley, Berkeley, CA, 94720-3220, USA
| | - Michael J Conboy
- Department of Bioengineering and QB3 Institute, University of California, Berkeley, Berkeley, CA, 94720-3220, USA
| | - Irina M Conboy
- Department of Bioengineering and QB3 Institute, University of California, Berkeley, Berkeley, CA, 94720-3220, USA.
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23
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Mukund K, Subramaniam S. Skeletal muscle: A review of molecular structure and function, in health and disease. WILEY INTERDISCIPLINARY REVIEWS. SYSTEMS BIOLOGY AND MEDICINE 2020; 12:e1462. [PMID: 31407867 PMCID: PMC6916202 DOI: 10.1002/wsbm.1462] [Citation(s) in RCA: 216] [Impact Index Per Article: 54.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Revised: 07/03/2019] [Accepted: 07/03/2019] [Indexed: 12/11/2022]
Abstract
Decades of research in skeletal muscle physiology have provided multiscale insights into the structural and functional complexity of this important anatomical tissue, designed to accomplish the task of generating contraction, force and movement. Skeletal muscle can be viewed as a biomechanical device with various interacting components including the autonomic nerves for impulse transmission, vasculature for efficient oxygenation, and embedded regulatory and metabolic machinery for maintaining cellular homeostasis. The "omics" revolution has propelled a new era in muscle research, allowing us to discern minute details of molecular cross-talk required for effective coordination between the myriad interacting components for efficient muscle function. The objective of this review is to provide a systems-level, comprehensive mapping the molecular mechanisms underlying skeletal muscle structure and function, in health and disease. We begin this review with a focus on molecular mechanisms underlying muscle tissue development (myogenesis), with an emphasis on satellite cells and muscle regeneration. We next review the molecular structure and mechanisms underlying the many structural components of the muscle: neuromuscular junction, sarcomere, cytoskeleton, extracellular matrix, and vasculature surrounding muscle. We highlight aberrant molecular mechanisms and their possible clinical or pathophysiological relevance. We particularly emphasize the impact of environmental stressors (inflammation and oxidative stress) in contributing to muscle pathophysiology including atrophy, hypertrophy, and fibrosis. This article is categorized under: Physiology > Mammalian Physiology in Health and Disease Developmental Biology > Developmental Processes in Health and Disease Models of Systems Properties and Processes > Cellular Models.
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Affiliation(s)
- Kavitha Mukund
- Department of BioengineeringUniversity of CaliforniaSan DiegoCalifornia
| | - Shankar Subramaniam
- Department of Bioengineering, Bioinformatics & Systems BiologyUniversity of CaliforniaSan DiegoCalifornia
- Department of Computer Science and EngineeringUniversity of CaliforniaSan DiegoCalifornia
- Department of Cellular and Molecular Medicine and NanoengineeringUniversity of CaliforniaSan DiegoCalifornia
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24
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Hughes DC, Marcotte GR, Baehr LM, West DWD, Marshall AG, Ebert SM, Davidyan A, Adams CM, Bodine SC, Baar K. Alterations in the muscle force transfer apparatus in aged rats during unloading and reloading: impact of microRNA-31. J Physiol 2019; 596:2883-2900. [PMID: 29726007 DOI: 10.1113/jp275833] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Accepted: 03/16/2018] [Indexed: 12/14/2022] Open
Abstract
KEY POINTS Force transfer is integral for maintaining skeletal muscle structure and function. One important component is dystrophin. There is limited understanding of how force transfer is impacted by age and loading. Here, we investigate the force transfer apparatus in muscles of adult and old rats exposed to periods of disuse and reloading. Our results demonstrate an increase in dystrophin protein during the reloading phase in the adult tibialis anterior muscle that is delayed in the old muscle. The consequence of this delay is an increased susceptibility towards contraction-induced muscle injury. Central to the lack of dystrophin protein is an increase in miR-31, a microRNA that inhibits dystrophin translation. In vivo electroporation with a miR-31 sponge led to increased dystrophin protein and decreased contraction-induced muscle injury in old skeletal muscle. Overall, our results detail the importance of the force transfer apparatus and provide new mechanisms for contraction-induced injury in ageing skeletal muscle. ABSTRACT In healthy muscle, the dystrophin-associated glycoprotein complex (DGC), the integrin/focal adhesion complex, intermediate filaments and Z-line proteins transmit force from the contractile proteins to the extracellular matrix. How loading and age affect these proteins is poorly understood. The experiments reported here sought to determine the effect of ageing on the force transfer apparatus following muscle unloading and reloading. Adult (9 months) and old (28 months) rats were subjected to 14 days of hindlimb unloading and 1, 3, 7 and 14 days of reloading. The DGC complex, intermediate filament and Z-line protein and mRNA levels, as well as dystrophin-targeting miRNAs (miR-31, -146b and -374) were examined in the tibialis anterior (TA) and medial gastrocnemius muscles at both ages. There was a significant increase in dystrophin protein levels (2.79-fold) upon 3 days of reloading in the adult TA muscle that did not occur in the old rats (P ≤ 0.05), and the rise in dystrophin protein occurred independent of dystrophin mRNA. The disconnect between dystrophin protein and mRNA levels can partially be explained by age-dependent differences in miR-31. The impaired dystrophin response in aged muscle was followed by an increase in other force transfer proteins (β-dystroglycan, desmuslin and LIM) that was not sufficient to prevent membrane disruption and muscle injury early in the reloading period. Inserting a miR-31 sponge increased dystrophin protein and decreased contraction-induced injury in the TA (P ≤ 0.05). Collectively, these data suggest that increased miR-31 with age contributes to an impaired dystrophin response and increased muscle injury after disuse.
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Affiliation(s)
- David C Hughes
- Department of Neurobiology, Physiology and Behavior, University of California Davis, Davis, CA, USA
| | - George R Marcotte
- Department of Neurobiology, Physiology and Behavior, University of California Davis, Davis, CA, USA
| | - Leslie M Baehr
- Department of Physiology and Membrane Biology, University of California Davis, Davis, CA, USA.,VA Northern California Health Care System, Mather, CA, USA
| | - Daniel W D West
- Department of Physiology and Membrane Biology, University of California Davis, Davis, CA, USA.,VA Northern California Health Care System, Mather, CA, USA
| | - Andrea G Marshall
- Department of Neurobiology, Physiology and Behavior, University of California Davis, Davis, CA, USA.,Department of Physiology and Membrane Biology, University of California Davis, Davis, CA, USA
| | - Scott M Ebert
- Department of Internal Medicine, University of Iowa, Iowa City, IA, USA.,Fraternal Order of Eagles Diabetes Research Center, University of Iowa, Iowa City, IA, USA.,Iowa City Veterans Affairs Medical Center, Iowa City, IA, USA
| | - Arik Davidyan
- Molecular, Cellular, and Integrative Physiology Graduate Group, University of California Davis, Davis, CA, USA
| | - Christopher M Adams
- Department of Internal Medicine, University of Iowa, Iowa City, IA, USA.,Fraternal Order of Eagles Diabetes Research Center, University of Iowa, Iowa City, IA, USA.,Iowa City Veterans Affairs Medical Center, Iowa City, IA, USA
| | - Sue C Bodine
- Department of Neurobiology, Physiology and Behavior, University of California Davis, Davis, CA, USA.,Department of Physiology and Membrane Biology, University of California Davis, Davis, CA, USA.,VA Northern California Health Care System, Mather, CA, USA
| | - Keith Baar
- Department of Neurobiology, Physiology and Behavior, University of California Davis, Davis, CA, USA.,Department of Physiology and Membrane Biology, University of California Davis, Davis, CA, USA.,VA Northern California Health Care System, Mather, CA, USA
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25
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Takegaki J, Sase K, Fujita S. Repeated bouts of resistance exercise attenuate mitogen-activated protein-kinase signal responses in rat skeletal muscle. Biochem Biophys Res Commun 2019; 520:73-78. [PMID: 31582215 DOI: 10.1016/j.bbrc.2019.09.050] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Accepted: 09/12/2019] [Indexed: 11/24/2022]
Abstract
Resistance exercise training induces skeletal muscle hypertrophy, but repeated bouts gradually attenuate this anabolic effect. Attenuation of mechanistic target of rapamycin complex 1 (mTORC1) activation by repetitive resistance exercise is involved in this process, but the mechanism leading to inactivation of mTORC1 remains unclear. In this study, we investigated repetition-dependent changes in mitogen-activated protein kinases (MAPKs) and the 90-kDa ribosomal S6 kinase (p90RSK), upstream regulators of mTORC1, in a rat resistance-exercise model. Resistance exercise was associated with increased phosphorylation of 70-kDa ribosomal protein S6 kinase (Thr389), but its magnitude was decreased with repeated bouts. Additionally, phosphorylation of extracellular signal-regulated kinase (ERK) 1/2 (Thr202/Tyr204) and p38 MAPK (Thr180/Tyr182), which are MAPKs, decreased with repeated bouts. A similar result was also observed for p90RSK phosphorylation (Thr573). These observations indicate that repeated bouts desensitized ERK1/2 and p38 MAPK, subsequently attenuating p90RSK phosphorylation. This reduction in p90RSK phosphorylation may have been partly responsible for the blunting of mTORC1 activation by resistance exercise.
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Affiliation(s)
- Junya Takegaki
- Ritsumeikan Global Innovation Research Organization, Ritsumeikan University, 1-1-1 Noji-higashi, Kusatsu, Shiga, 525-8577, Japan.
| | - Kohei Sase
- Ritsumeikan Global Innovation Research Organization, Ritsumeikan University, 1-1-1 Noji-higashi, Kusatsu, Shiga, 525-8577, Japan; Faculty of Sport and Health Science, Ritsumeikan University, 1-1-1 Noji-higashi, Kusatsu, Shiga, 525-8577, Japan.
| | - Satoshi Fujita
- Faculty of Sport and Health Science, Ritsumeikan University, 1-1-1 Noji-higashi, Kusatsu, Shiga, 525-8577, Japan.
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Boppart MD, Mahmassani ZS. Integrin signaling: linking mechanical stimulation to skeletal muscle hypertrophy. Am J Physiol Cell Physiol 2019; 317:C629-C641. [PMID: 31314586 DOI: 10.1152/ajpcell.00009.2019] [Citation(s) in RCA: 71] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The α7β1-integrin is a transmembrane adhesion protein that connects laminin in the extracellular matrix (ECM) with actin in skeletal muscle fibers. The α7β1-integrin is highly expressed in skeletal muscle and is concentrated at costameres and myotendious junctions, providing the opportunity to transmit longitudinal and lateral forces across the membrane. Studies have demonstrated that α7-integrin subunit mRNA and protein are upregulated following eccentric contractions as a mechanism to reinforce load-bearing structures and resist injury with repeated bouts of exercise. It has been hypothesized for many years that the integrin can also promote protein turnover in a manner that can promote beneficial adaptations with resistance exercise training, including hypertrophy. This review provides basic information about integrin structure and activation and then explores its potential to serve as a critical mechanosensor and activator of muscle protein synthesis and growth. Overall, the hypothesis is proposed that the α7β1-integrin can contribute to mechanical-load induced skeletal muscle growth via an mammalian target of rapamycin complex 1-independent mechanism.
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Affiliation(s)
- Marni D Boppart
- Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Urbana, Illinois.,Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois
| | - Ziad S Mahmassani
- Department of Physical Therapy and Athletic Training, University of Utah, Salt Lake City, Utah
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27
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Hansson B, Olsen LA, Nicoll JX, von Walden F, Melin M, Strömberg A, Rullman E, Gustafsson T, Fry AC, Fernandez-Gonzalo R, Lundberg TR. Skeletal muscle signaling responses to resistance exercise of the elbow extensors are not compromised by a preceding bout of aerobic exercise. Am J Physiol Regul Integr Comp Physiol 2019; 317:R83-R92. [DOI: 10.1152/ajpregu.00022.2019] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The current study examined the effects of a preceding bout of aerobic exercise (AE) on subsequent molecular signaling to resistance exercise (RE) of the elbow extensors. Eleven men performed unilateral elbow-extensor AE (~45 min at 70% peak workload) followed by unilateral RE (4 × 7 maximal repetitions) for both arms. Thus, one arm performed AE+RE interspersed with 15 min recovery, whereas the other arm conducted RE alone. Muscle biopsies were taken from the triceps brachii of each arm immediately before (PRE) and 15 min (POST1) and 3 h (POST2) after RE. Molecular markers involved in translation initiation, protein breakdown, mechanosignaling, and ribosome biogenesis were analyzed. Peak power during RE was reduced by 24% (±19%) when preceded by AE ( P < 0.05). Increases in PGC1a and MuRF1 expression were greater from PRE to POST2 in AE+RE compared with RE (18- vs. 3.5- and 4- vs. 2-fold, respectively, interaction, P < 0.05). Myostatin mRNA decreased in both arms ( P < 0.05). Phosphorylation of AMPK (Thr172) increased (2.5-fold), and 4E-BP1 (Thr37/46) decreased (2.0-fold), after AE (interactions, P < 0.05). p70 S6K, yes-associated protein, and c-Jun NH2-terminal kinase phosphorylation were unaltered, whereas focal adhesion kinase decreased ~1.5-fold, and β1-integrin increased ~1.3- to 1.5-fold, (time effect, P < 0.05). Abundance of 45S pre-ribosomal (r)RNA (internally transcribed spacer, ITS) decreased (~30%) after AE (interaction, P < 0.05), whereas CMYC mRNA was greater in AE+RE compared with RE (12-fold, P < 0.05). POLR1B abundance increased after both AE+RE and RE. All together, our results suggest that a single bout of AE leads to an immediate decrease in signaling for translation initiation and ribosome biogenesis. Yet, this did not translate into altered RE-induced signaling during the 3-h postexercise recovery period.
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Affiliation(s)
- Björn Hansson
- Division of Clinical Physiology, Department of Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden
- Unit of Clinical Physiology, Karolinska University Hospital, Stockholm, Sweden
| | - Luke A. Olsen
- Department of Biomedical Sciences, University of Kansas Medical Center, Kansas City, Kansas
| | - Justin X. Nicoll
- Department of Kinesiology, California State University, Northridge, California
| | - Ferdinand von Walden
- Department of Women’s and Children’s Health, Karolinska Institutet, Stockholm, Sweden
| | - Michael Melin
- Division of Clinical Physiology, Department of Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden
- Unit of Clinical Physiology, Karolinska University Hospital, Stockholm, Sweden
- Heart and Vascular Theme, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden
| | - Anna Strömberg
- Division of Clinical Physiology, Department of Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden
- Unit of Clinical Physiology, Karolinska University Hospital, Stockholm, Sweden
| | - Eric Rullman
- Division of Clinical Physiology, Department of Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden
- Unit of Clinical Physiology, Karolinska University Hospital, Stockholm, Sweden
- Heart and Vascular Theme, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden
| | - Thomas Gustafsson
- Division of Clinical Physiology, Department of Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden
- Unit of Clinical Physiology, Karolinska University Hospital, Stockholm, Sweden
| | - Andrew C. Fry
- Osness Human Performance Laboratories, University of Kansas, Lawrence, Kansas
| | - Rodrigo Fernandez-Gonzalo
- Division of Clinical Physiology, Department of Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden
- Unit of Clinical Physiology, Karolinska University Hospital, Stockholm, Sweden
| | - Tommy R. Lundberg
- Division of Clinical Physiology, Department of Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden
- Unit of Clinical Physiology, Karolinska University Hospital, Stockholm, Sweden
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28
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Naimo MA, Rader EP, Ensey J, Kashon ML, Baker BA. Reduced frequency of resistance-type exercise training promotes adaptation of the aged skeletal muscle microenvironment. J Appl Physiol (1985) 2019; 126:1074-1087. [PMID: 30676867 DOI: 10.1152/japplphysiol.00582.2018] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The purpose of this study was to characterize the growth and remodeling molecular signaling response in aged skeletal muscle following 1 mo of "resistance-type exercise" training. Male Fischer 344 × Brown Norway hybrid rats aged 3 (young) and 30 mo (old) underwent stretch-shortening contraction (SSC) loading 2 or 3 days/wk; muscles were removed 72 h posttraining. Young rats SSC loaded 3 (Y3x) or 2 days/wk (Y2x) adapted via increased work performance. Old rats SSC loaded 3 days/wk (O3x) maladapted via decreased negative work; however, old rats SSC loaded 2 days/wk (O2x) adapted through improved negative and positive work. Y3x, Y2x, and O2x, but not O3x, displayed hypertrophy via larger fiber area and myonuclear domains. Y3x, Y2x, and O2x differentially expressed 19, 30, and 8 phosphatidylinositol 3-kinase-Akt genes, respectively, whereas O3x only expressed 2. Bioinformatics analysis revealed that rats in the adapting groups presented growth and remodeling processes (i.e., increased protein synthesis), whereas O3x demonstrated inflammatory signaling. In conclusion, reducing SSC-loading frequency in aged rodents positively influences the molecular signaling microenvironment, promoting muscle adaptation. NEW & NOTEWORTHY Decreasing resistance-type exercise training frequency in old rodents led to adaptation through enhancements in performance, fiber areas, and myonuclear domains. Modifying frequency influenced the molecular environment through improvements in phosphatidylinositol 3-kinase-Akt pathway-specific expression and bioinformatics indicating increased protein synthesis. Reducing training frequency may be appropriate in older individuals who respond unfavorably to higher frequencies (i.e., maladaptation); overall, modifying the parameters of the exercise prescription can affect the cellular environment, ultimately leading to adaptive or maladaptive outcomes.
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Affiliation(s)
- Marshall A Naimo
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention , Morgantown, West Virginia.,Division of Exercise Physiology, School of Medicine, West Virginia University , Morgantown, West Virginia
| | - Erik P Rader
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention , Morgantown, West Virginia
| | - James Ensey
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention , Morgantown, West Virginia
| | - Michael L Kashon
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention , Morgantown, West Virginia
| | - Brent A Baker
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention , Morgantown, West Virginia
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29
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Pardo-Saganta A, Calvo IA, Saez B, Prosper F. Role of the Extracellular Matrix in Stem Cell Maintenance. CURRENT STEM CELL REPORTS 2019. [DOI: 10.1007/s40778-019-0149-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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30
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Silva Garcia JM, Panitch A, Calve S. Functionalization of hyaluronic acid hydrogels with ECM-derived peptides to control myoblast behavior. Acta Biomater 2019; 84:169-179. [PMID: 30508655 DOI: 10.1016/j.actbio.2018.11.030] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Revised: 10/31/2018] [Accepted: 11/19/2018] [Indexed: 01/07/2023]
Abstract
Volumetric muscle loss (VML) occurs when skeletal muscle injury is too large for the body to fully self-repair. Typically, fibrotic tissue fills the void, which reduces muscle functionality and limb movement. Although a wide variety of natural and synthetic scaffolds have been studied with the purpose of providing the appropriate structural support, to date no scaffold has significantly restored muscle functionality after VML. Satellite cells, adult stem cells within the muscle capable of restoring smaller injuries, are sensitive to the stiffness and composition of the surrounding environment. Scaffolds that only address structural support are not sufficient to restore functionality and instead need to be designed to both promote satellite cell activation and prevent excessive fibroblast recruitment. The objective of this study was to design a scaffold that mimicked the regenerative environment and determine how the biomechanical properties differentially influence myogenic precursor and connective tissue cells. One of the main extracellular matrix (ECM) molecules upregulated during regeneration is hyaluronic acid (HA). Therefore, thiol-modified HA and poly(ethylene glycol) diacrylate hydrogels were generated and functionalized with peptides based on ECM known to influence regeneration, including fibronectin, laminin and tenascin-C. Scaffolds with different stiffness were created by varying HA content. The influence of HA stiffness and peptide functionalization on myogenic precursor and connective tissue cell proliferation, migration and gene expression was quantified. Our results indicated that HA hydrogels functionalized with the laminin peptide, IKVAV, show potential due to the enhanced promotion of myogenic cell behaviors including migration, proliferation and an increase in relevant transcription factors. STATEMENT OF SIGNIFICANCE: The goal of this study was to identify hyaluronic acid (HA) hydrogels with peptide and stiffness combinations that will direct muscle-derived cells towards regenerating phenotypes. While the interaction of skeletal muscle with RGD-functionalized HA hydrogels has been investigated, none of the other peptides described in this study had been used in the context of HA-based scaffolds and skeletal muscle-derived cells. Notably, the response of cells to variations in mechanics was dependent on ECM coating and lineage. The 3% HA functionalized with the laminin peptide, IKVAV, showed the most promise for future in vivo studies, as these hydrogels best promoted myoblast cell proliferation, attachment and spreading, enhanced migration over connective tissue cells and upregulated transcription factors associated with activated satellite cells.
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31
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Olsen LA, Nicoll JX, Fry AC. The skeletal muscle fiber: a mechanically sensitive cell. Eur J Appl Physiol 2019; 119:333-349. [PMID: 30612167 DOI: 10.1007/s00421-018-04061-x] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Accepted: 12/21/2018] [Indexed: 12/12/2022]
Abstract
The plasticity of skeletal muscle, whether an increase in size, change in metabolism, or alteration in structural properties, is in a continuous state of flux largely dependent upon physical activity. Much of the past research has expounded upon these ever-changing aspects of the muscle fiber following exercise. Specifically, endocrine and paracrine signaling have been heavily investigated lending to much of the past literature comprised of such endocrinological dynamics following muscle activity. Mechanotransduction, the ability of a cell to convert a mechanical stimulus into an intracellular biochemical response, has garnered much less attention. Recent work, however, has demonstrated the physical continuity of the muscle fiber, specifically demonstrating a continuous physical link between the extracellular matrix (ECM), cytoskeleton, and nuclear matrix as a means to rapidly regulate gene expression following a mechanical stimulus. Similarly, research has shown mechanical stimuli to directly influence cytoplasmic signaling whether through oxidative adaptations, increased muscle size, or enhanced muscle integrity. Regrettably, minimal research has investigated the role that exercise may play within the mechanotransducing signaling cascades. This proposed line of study may prove paramount as muscle-related diseases greatly impact one's ability to lead an independent lifestyle along with contributing a substantial burden upon the economy. Thus, this review explores both biophysical and biochemical mechanotransduction, and how these signaling pathways may be influenced following exercise.
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Affiliation(s)
- Luke A Olsen
- Biomedical Sciences, University of Kansas Medical Center, Kansas City, KS, 66160, USA
| | - Justin X Nicoll
- Department of Kinesiology, California State University, Northridge, CA, 91330-8287, USA
| | - Andrew C Fry
- Department of Health, Sport, and Exercise Sciences, University of Kansas, Lawrence, KS, 66045, USA.
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32
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So WK, Cheung TH. Molecular Regulation of Cellular Quiescence: A Perspective from Adult Stem Cells and Its Niches. Methods Mol Biol 2018; 1686:1-25. [PMID: 29030809 DOI: 10.1007/978-1-4939-7371-2_1] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Cellular quiescence is a reversible growth arrest state. In response to extracellular environment, quiescent cells are capable of resuming proliferation for tissue homeostasis and tissue regeneration. Subpopulations of adult stem cells remain quiescent and reside in their specialized stem cell niches. Within the niche, they interact with a repertoire of niche components. Niche integrates signals to maintain quiescence or gear stem cells toward regeneration. Recent studies provide insights into the regulatory components of stem cell niche and their influence on residing stem cells. Aberrant niche activities perturb stem cell quiescence and activation, compromise stem cell functions, and contribute to tissue aging and disease pathogenesis. This review covers current knowledge regarding cellular quiescence with a focus on original and emerging concepts of how niches influence stem cell quiescence.
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Affiliation(s)
- Wai-Kin So
- Division of Life Science, Center for Stem Cell Research, State Key Laboratory of Molecular Neuroscience, Center of Systems Biology and Human Health, Institute for Advanced Study, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Tom H Cheung
- Division of Life Science, Center for Stem Cell Research, State Key Laboratory of Molecular Neuroscience, Center of Systems Biology and Human Health, Institute for Advanced Study, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China.
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33
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Bamman MM, Roberts BM, Adams GR. Molecular Regulation of Exercise-Induced Muscle Fiber Hypertrophy. Cold Spring Harb Perspect Med 2018; 8:cshperspect.a029751. [PMID: 28490543 DOI: 10.1101/cshperspect.a029751] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Skeletal muscle hypertrophy is a widely sought exercise adaptation to counteract the muscle atrophy of aging and disease, or to improve athletic performance. While this desired muscle enlargement is a well-known adaptation to resistance exercise training (RT), the mechanistic underpinnings are not fully understood. The purpose of this review is thus to provide the reader with a summary of recent advances in molecular mechanisms-based on the most current literature-that are thought to promote RT-induced muscle hypertrophy. We have therefore focused this discussion on the following areas of fertile investigation: ribosomal function and biogenesis, muscle stem (satellite) cell activity, transcriptional regulation, mechanotransduction, and myokine signaling.
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Affiliation(s)
- Marcas M Bamman
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama 35294.,UAB Center for Exercise Medicine, University of Alabama at Birmingham, Birmingham, Alabama 35205.,Geriatric Research, Education, and Clinical Center, Veterans' Affairs Medical Center, Birmingham, Alabama 35233
| | - Brandon M Roberts
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama 35294.,UAB Center for Exercise Medicine, University of Alabama at Birmingham, Birmingham, Alabama 35205
| | - Gregory R Adams
- Department of Physiology and Biophysics, University of California Irvine, Irvine, California 92617
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34
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Hughes DC, Ellefsen S, Baar K. Adaptations to Endurance and Strength Training. Cold Spring Harb Perspect Med 2018; 8:cshperspect.a029769. [PMID: 28490537 DOI: 10.1101/cshperspect.a029769] [Citation(s) in RCA: 152] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The capacity for human exercise performance can be enhanced with prolonged exercise training, whether it is endurance- or strength-based. The ability to adapt through exercise training allows individuals to perform at the height of their sporting event and/or maintain peak physical condition throughout the life span. Our continued drive to understand how to prescribe exercise to maximize health and/or performance outcomes means that our knowledge of the adaptations that occur as a result of exercise continues to evolve. This review will focus on current and new insights into endurance and strength-training adaptations and will highlight important questions that remain as far as how we adapt to training.
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Affiliation(s)
- David C Hughes
- Department of Neurobiology, Physiology and Behavior, Functional Molecular Biology Laboratory, University of California Davis, Davis, California 95616
| | - Stian Ellefsen
- Section of Sports Sciences, Lillehammer University College, 2604 Lillehammer, Norway.,Innlandet Hospital Trust, 2380 Brumunddal, Norway
| | - Keith Baar
- Department of Neurobiology, Physiology and Behavior, Functional Molecular Biology Laboratory, University of California Davis, Davis, California 95616
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35
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Takagi R, Ogasawara R, Takegaki J, Tamura Y, Tsutaki A, Nakazato K, Ishii N. Past injurious exercise attenuates activation of primary calcium-dependent injury pathways in skeletal muscle during subsequent exercise. Physiol Rep 2018; 6:e13660. [PMID: 29595913 PMCID: PMC5875535 DOI: 10.14814/phy2.13660] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2018] [Accepted: 02/22/2018] [Indexed: 11/24/2022] Open
Abstract
Past contraction‐induced skeletal muscle injury reduces the degree of subsequent injury; this phenomenon is called the “repeated bout effect (RBE).” This study addresses the mechanisms underlying the RBE, focusing on primary calcium‐dependent injury pathways. Wistar rats were subdivided into single injury (SI) and repeated injury (RI) groups. At age 10 weeks, the right gastrocnemius muscle in each rat in the RI group was subjected to strenuous eccentric contractions (ECs). Subsequently, mild ECs were imposed on the same muscle of each rat at 14 weeks of age in both groups. One day after the exercise, the RI group showed a lower strength deficit than did the SI group, and neither group manifested any increase in membrane permeability. The concentration of protein carbonyls and activation of total calpain increased after ECs given at the age of 14 weeks. Nonetheless, these increases were lower in the RI group than in the SI group. Furthermore, calcium‐dependent autolysis of calpain‐1 and calpain‐3 in the RI group was diminished as compared with that in the SI group. Although peak ankle joint torque and total force generation during ECs at the age of 14 weeks were similar between the two groups, phosphorylation of JNK (Thr183/Tyr185), an indicator of mechanical stress applied to a muscle, was lower in the RI group than in the SI group. These findings suggest that activation of the primary calcium‐dependent injury pathways is attenuated by past injurious exercise, and mechanical stress applied to muscle fibers during ECs may decrease in the RBE.
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Affiliation(s)
- Ryo Takagi
- Graduate School of Health and Sport Science, Nippon Sport Science University, Tokyo, Japan.,Department of Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Riki Ogasawara
- Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Aichi, Japan
| | - Junya Takegaki
- Department of Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Yuki Tamura
- Graduate School of Health and Sport Science, Nippon Sport Science University, Tokyo, Japan
| | - Arata Tsutaki
- Graduate School of Health and Sport Science, Nippon Sport Science University, Tokyo, Japan
| | - Koichi Nakazato
- Graduate School of Health and Sport Science, Nippon Sport Science University, Tokyo, Japan
| | - Naokata Ishii
- Department of Life Sciences, The University of Tokyo, Tokyo, Japan
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Takagi R, Ogasawara R, Takegaki J, Tsutaki A, Nakazato K, Ishii N. Influence of past injurious exercise on fiber type-specific acute anabolic response to resistance exercise in skeletal muscle. J Appl Physiol (1985) 2018; 124:16-22. [PMID: 28912360 DOI: 10.1152/japplphysiol.00480.2017] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
We investigated the influence of past injurious exercise on anabolic response of skeletal muscle fibers to resistance exercise (RE). Wistar rats were divided into exercise (E) and exercise-after-injury (I-E) groups. At age 10 wk, the right gastrocnemius muscle in each rat in the I-E group was subjected to strenuous eccentric contractions. Subsequently, RE was imposed on the same muscle of each rat at 14 wk of age in both groups. Peak joint torque and total force generation per body mass during RE were similar between the groups. Muscle protein synthesis (MPS) in the I-E group was higher than that in the E group 6 h after RE. Furthermore, levels of phospho-p70S6 kinase (Thr389) and phospho-ribosomal protein S6 (phospho-rpS6) (Ser240/244), a downstream target of p70S6 kinase, were higher in the I-E group than in the E group. For the anabolic response in each fiber type, the I-E group showed a higher MPS response in type IIb, IIa, and I fibers and a higher phospho-rpS6 response in type IIx, IIa, and I fibers than the E group. In the I-E group, the relative content of myosin heavy chain (MHC) IIa was higher and that of MHC IIb was lower than those in the E group. In addition, type IIa fibers showed a lower MPS response to RE than type IIb fibers in the I-E group. In conclusion, the past injurious exercise enhanced the MPS and phospho-rpS6 responses in type IIb, IIa, and I fibers and type IIx, IIa, and I fibers, respectively. NEW & NOTEWORTHY Past injurious exercise increased the muscle protein synthesis (MPS) response and mammalian target of rapamycin complex 1 (mTORC1) signaling activation to resistance exercise. In the responses of each fiber type, the past injurious exercise increased the MPS and phosphorylation ribosomal protein (Ser240/244) responses in type IIb, IIa, and I fibers and type IIx, IIa, and I fibers, respectively.
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Affiliation(s)
- Ryo Takagi
- Graduate School of Health and Sport Science, Nippon Sport Science University , Tokyo , Japan.,Department of Life Sciences, The University of Tokyo , Tokyo , Japan
| | - Riki Ogasawara
- Department of Life Science and Applied Chemistry, Nagoya Institute of Technology , Aichi , Japan
| | - Junya Takegaki
- Department of Life Sciences, The University of Tokyo , Tokyo , Japan
| | - Arata Tsutaki
- Graduate School of Health and Sport Science, Nippon Sport Science University , Tokyo , Japan
| | - Koichi Nakazato
- Graduate School of Health and Sport Science, Nippon Sport Science University , Tokyo , Japan
| | - Naokata Ishii
- Department of Life Sciences, The University of Tokyo , Tokyo , Japan
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Pingel J, Suhr F. Are mechanically sensitive regulators involved in the function and (patho)physiology of cerebral palsy-related contractures? J Muscle Res Cell Motil 2017; 38:317-330. [PMID: 29190010 DOI: 10.1007/s10974-017-9489-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Accepted: 11/21/2017] [Indexed: 12/17/2022]
Abstract
Skeletal muscle tissue is mechanosensitive, as it is able to sense mechanical impacts and to translate these into biochemical signals making the tissue adapt. Among its mechanosensitive nature, skeletal muscle tissue is the largest metabolic organ of the human body. Disturbances in skeletal muscle mechanosensing and metabolism cause and contribute to many diseases, i.e. muscular dystrophies/myopathies, cardiovascular diseases, COPD or diabetes mellitus type 2. A less commonly focused muscle-related disorder is clinically known as muscle contractures that derive from cerebral palsy (CP) conditions in young and adults. Muscle contractures are characterized by gradually increasing passive muscle stiffness resulting in complete fixation of joints. Different mechanisms have been identified in CP-related contractures, i.e. altered calcium handling, altered metabolism or altered titin regulation. The muscle-related extracellular matrix (ECM), specifically collagens, plays a role in CP-related contractures. Herein, we focus on mechanically sensitive complexes, known as costameres (Cstms), and discuss their potential role in CP-related contractures. We extend our discussion to the ECM due to the limited knowledge of its role in CP-related contractures. The aims of this review are (1) to summarize CP-related contracture mechanisms, (2) to raise novel hypotheses on the genesis of contractures with a focus on Cstms, and (3) to stimulate novel approaches to study CP-related contractures.
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Affiliation(s)
- Jessica Pingel
- Motor Control Lab, Department of Neuroscience and Pharmacology, University of Copenhagen, Blegdamsvej 3b, 2200, Copenhagen N, Denmark.
| | - Frank Suhr
- Exercise Physiology Research Group, Department of Movement Sciences, Biomedical Sciences Group, KU Leuven, Tervuursevest 101, box 1500, 3001, Leuven, Belgium.
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Hughes DC, Marcotte GR, Marshall AG, West DWD, Baehr LM, Wallace MA, Saleh PM, Bodine SC, Baar K. Age-related Differences in Dystrophin: Impact on Force Transfer Proteins, Membrane Integrity, and Neuromuscular Junction Stability. J Gerontol A Biol Sci Med Sci 2017; 72:640-648. [PMID: 27382038 DOI: 10.1093/gerona/glw109] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Accepted: 05/27/2016] [Indexed: 11/13/2022] Open
Abstract
The loss of muscle strength with age has been studied from the perspective of a decline in muscle mass and neuromuscular junction (NMJ) stability. A third potential factor is force transmission. The purpose of this study was to determine the changes in the force transfer apparatus within aging muscle and the impact on membrane integrity and NMJ stability. We measured an age-related loss of dystrophin protein that was greatest in the flexor muscles. The loss of dystrophin protein occurred despite a twofold increase in dystrophin mRNA. Importantly, this disparity could be explained by the four- to fivefold upregulation of the dystromir miR-31. To compensate for the loss of dystrophin protein, aged muscle contained increased α-sarcoglycan, syntrophin, sarcospan, laminin, β1-integrin, desmuslin, and the Z-line proteins α-actinin and desmin. In spite of the adaptive increase in other force transfer proteins, over the 48 hours following lengthening contractions, the old muscles showed more signs of impaired membrane integrity (fourfold increase in immunoglobulin G-positive fibers and 70% greater dysferlin mRNA) and NMJ instability (14- to 96-fold increases in Runx1, AchRδ, and myogenin mRNA). Overall, these data suggest that age-dependent alterations in dystrophin leave the muscle membrane and NMJ more susceptible to contraction-induced damage even before changes in muscle mass are obvious.
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Affiliation(s)
| | | | - Andrea G Marshall
- Department of Neurobiology, Physiology and Behavior and.,Department of Physiology and Membrane Biology, University of California, Davis.,VA Northern California Health Care System, Mather
| | - Daniel W D West
- Department of Physiology and Membrane Biology, University of California, Davis.,VA Northern California Health Care System, Mather
| | - Leslie M Baehr
- Department of Physiology and Membrane Biology, University of California, Davis.,VA Northern California Health Care System, Mather
| | | | | | - Sue C Bodine
- Department of Neurobiology, Physiology and Behavior and.,Department of Physiology and Membrane Biology, University of California, Davis.,VA Northern California Health Care System, Mather
| | - Keith Baar
- Department of Neurobiology, Physiology and Behavior and.,Department of Physiology and Membrane Biology, University of California, Davis.,VA Northern California Health Care System, Mather
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SU9516 Increases α7β1 Integrin and Ameliorates Disease Progression in the mdx Mouse Model of Duchenne Muscular Dystrophy. Mol Ther 2017; 25:1395-1407. [PMID: 28391962 DOI: 10.1016/j.ymthe.2017.03.022] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Revised: 03/10/2017] [Accepted: 03/14/2017] [Indexed: 01/06/2023] Open
Abstract
Duchenne muscular dystrophy (DMD) is a fatal muscle disease caused by mutations in the dystrophin gene, resulting in a complete loss of the dystrophin protein. Dystrophin is a critical component of the dystrophin glycoprotein complex (DGC), which links laminin in the extracellular matrix to the actin cytoskeleton within myofibers and provides resistance to shear stresses during muscle activity. Loss of dystrophin in DMD patients results in a fragile sarcolemma prone to contraction-induced muscle damage. The α7β1 integrin is a laminin receptor protein complex in skeletal and cardiac muscle and a major modifier of disease progression in DMD. In a muscle cell-based screen for α7 integrin transcriptional enhancers, we identified a small molecule, SU9516, that promoted increased α7β1 integrin expression. Here we show that SU9516 leads to increased α7B integrin in murine C2C12 and human DMD patient myogenic cell lines. Oral administration of SU9516 in the mdx mouse model of DMD increased α7β1 integrin in skeletal muscle, ameliorated pathology, and improved muscle function. We show that these improvements are mediated through SU9516 inhibitory actions on the p65-NF-κB pro-inflammatory and Ste20-related proline alanine rich kinase (SPAK)/OSR1 signaling pathways. This study identifies a first in-class α7 integrin-enhancing small-molecule compound with potential for the treatment of DMD.
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Mahmassani ZS, Son K, Pincu Y, Munroe M, Drnevich J, Chen J, Boppart MD. α 7β 1 Integrin regulation of gene transcription in skeletal muscle following an acute bout of eccentric exercise. Am J Physiol Cell Physiol 2017; 312:C638-C650. [PMID: 28274919 DOI: 10.1152/ajpcell.00106.2016] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Revised: 02/27/2017] [Accepted: 02/28/2017] [Indexed: 02/06/2023]
Abstract
The α7β1 integrin is concentrated at the costameres of skeletal muscle and provides a critical link between the actin cytoskeleton and laminin in the basement membrane. We previously demonstrated that expression of the α7BX2 integrin subunit (MCK:α7BX2) preserves muscle integrity and enhances myofiber cross-sectional area following eccentric exercise. The purpose of this study was to utilize gene expression profiling to reveal potential mechanisms by which the α7BX2-integrin contributes to improvements in muscle growth after exercise. A microarray analysis was performed using RNA extracted from skeletal muscle of wild-type or transgenic mice under sedentary conditions and 3 h following an acute bout of downhill running. Genes with false discovery rate probability values below the cutoff of P < 0.05 (n = 73) were found to be regulated by either exercise or transgene expression. KEGG pathway analysis detected upregulation of genes involved in endoplasmic reticulum protein processing with integrin overexpression. Targeted analyses verified increased transcription of Rpl13a, Nosip, Ang, Scl7a5, Gys1, Ndrg2, Hspa5, and Hsp40 as a result of integrin overexpression alone or in combination with exercise (P < 0.05). A significant increase in HSPA5 protein and a decrease in CAAT-enhancer-binding protein homologous protein (CHOP) were detected in transgenic muscle (P < 0.05). In vitro knockdown experiments verified integrin-mediated regulation of Scl7a5 The results from this study suggest that the α7β1 integrin initiates transcription of genes that allow for protection from stress, including activation of a beneficial unfolded protein response and modulation of protein synthesis, both which may contribute to positive adaptations in skeletal muscle as a result of engagement in eccentric exercise.
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Affiliation(s)
- Ziad S Mahmassani
- Department of Kinesiology and Community Health and Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois
| | - Kook Son
- Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois; and
| | - Yair Pincu
- Department of Kinesiology and Community Health and Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois
| | - Michael Munroe
- Department of Kinesiology and Community Health and Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois
| | - Jenny Drnevich
- Roy J. Carver Biotechnology Center, High Performance Biological Computing, University of Illinois at Urbana-Champaign, Urbana, Illinois
| | - Jie Chen
- Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois; and
| | - Marni D Boppart
- Department of Kinesiology and Community Health and Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois;
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Baumann CW, Rogers RG, Otis JS, Ingalls CP. Recovery of strength is dependent on mTORC1 signaling after eccentric muscle injury. Muscle Nerve 2016; 54:914-924. [PMID: 27015597 DOI: 10.1002/mus.25121] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/22/2016] [Indexed: 01/14/2023]
Abstract
INTRODUCTION Eccentric contractions may cause immediate and long-term reductions in muscle strength that can be recovered through increased protein synthesis rates. The purpose of this study was to determine whether the mechanistic target-of-rapamycin complex 1 (mTORC1), a vital controller of protein synthesis rates, is required for return of muscle strength after injury. METHODS Isometric muscle strength was assessed before, immediately after, and then 3, 7, and 14 days after a single bout of 150 eccentric contractions in mice that received daily injections of saline or rapamycin. RESULTS The bout of eccentric contractions increased the phosphorylation of mTORC1 (1.8-fold) and p70s6k1 (13.8-fold), mTORC1's downstream effector, 3 days post-injury. Rapamycin blocked mTORC1 and p70s6k1 phosphorylation and attenuated recovery of muscle strength (∼20%) at 7 and 14 days. CONCLUSION mTORC1 signaling is instrumental in the return of muscle strength after a single bout of eccentric contractions in mice. Muscle Nerve 54: 914-924, 2016.
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Affiliation(s)
- Cory Walter Baumann
- Muscle Biology Laboratory, Department of Kinesiology and Health, Georgia State University, Atlanta, Georgia, 30302-3975, USA
| | - Russell George Rogers
- Muscle Biology Laboratory, Department of Kinesiology and Health, Georgia State University, Atlanta, Georgia, 30302-3975, USA
| | - Jeffrey Scott Otis
- Muscle Biology Laboratory, Department of Kinesiology and Health, Georgia State University, Atlanta, Georgia, 30302-3975, USA
| | - Christopher Paul Ingalls
- Muscle Biology Laboratory, Department of Kinesiology and Health, Georgia State University, Atlanta, Georgia, 30302-3975, USA.
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Takagi R, Ogasawara R, Tsutaki A, Nakazato K, Ishii N. Regional adaptation of collagen in skeletal muscle to repeated bouts of strenuous eccentric exercise. Pflugers Arch 2016; 468:1565-72. [DOI: 10.1007/s00424-016-1860-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Revised: 07/13/2016] [Accepted: 07/21/2016] [Indexed: 10/21/2022]
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Allen DG, Whitehead NP, Froehner SC. Absence of Dystrophin Disrupts Skeletal Muscle Signaling: Roles of Ca2+, Reactive Oxygen Species, and Nitric Oxide in the Development of Muscular Dystrophy. Physiol Rev 2016; 96:253-305. [PMID: 26676145 DOI: 10.1152/physrev.00007.2015] [Citation(s) in RCA: 272] [Impact Index Per Article: 34.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Dystrophin is a long rod-shaped protein that connects the subsarcolemmal cytoskeleton to a complex of proteins in the surface membrane (dystrophin protein complex, DPC), with further connections via laminin to other extracellular matrix proteins. Initially considered a structural complex that protected the sarcolemma from mechanical damage, the DPC is now known to serve as a scaffold for numerous signaling proteins. Absence or reduced expression of dystrophin or many of the DPC components cause the muscular dystrophies, a group of inherited diseases in which repeated bouts of muscle damage lead to atrophy and fibrosis, and eventually muscle degeneration. The normal function of dystrophin is poorly defined. In its absence a complex series of changes occur with multiple muscle proteins showing reduced or increased expression or being modified in various ways. In this review, we will consider the various proteins whose expression and function is changed in muscular dystrophies, focusing on Ca(2+)-permeable channels, nitric oxide synthase, NADPH oxidase, and caveolins. Excessive Ca(2+) entry, increased membrane permeability, disordered caveolar function, and increased levels of reactive oxygen species are early changes in the disease, and the hypotheses for these phenomena will be critically considered. The aim of the review is to define the early damage pathways in muscular dystrophy which might be appropriate targets for therapy designed to minimize the muscle degeneration and slow the progression of the disease.
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Affiliation(s)
- David G Allen
- Sydney Medical School & Bosch Institute, University of Sydney, New South Wales, Australia; and Department of Physiology & Biophysics, University of Washington, Seattle, Washington
| | - Nicholas P Whitehead
- Sydney Medical School & Bosch Institute, University of Sydney, New South Wales, Australia; and Department of Physiology & Biophysics, University of Washington, Seattle, Washington
| | - Stanley C Froehner
- Sydney Medical School & Bosch Institute, University of Sydney, New South Wales, Australia; and Department of Physiology & Biophysics, University of Washington, Seattle, Washington
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da Rocha AL, Pereira BC, Pauli JR, de Souza CT, Teixeira GR, Lira FS, Cintra DE, Ropelle ER, Júnior CR, da Silva AS. Downhill Running Excessive Training Inhibits Hypertrophy in Mice Skeletal Muscles with Different Fiber Type Composition. J Cell Physiol 2015; 231:1045-56. [DOI: 10.1002/jcp.25197] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Accepted: 09/16/2015] [Indexed: 02/06/2023]
Affiliation(s)
- Alisson L. da Rocha
- Postgraduate Program in Rehabilitation and Functional Performance; Ribeirão Preto Medical School; University of São Paulo (USP); Ribeirão Preto São Paulo Brazil
| | - Bruno C. Pereira
- Postgraduate Program in Rehabilitation and Functional Performance; Ribeirão Preto Medical School; University of São Paulo (USP); Ribeirão Preto São Paulo Brazil
| | - José R. Pauli
- Sport Sciences Course; Faculty of Applied Sciences; State University of Campinas (UNICAMP); Limeira São Paulo Brazil
| | - Claudio T. de Souza
- Exercise Biochemistry and Physiology Laboratory Postgraduate Program in Health Sciences; Health Sciences Unit; University of Far Southern Santa Catarina; Criciúma Santa Catarina Brazil
| | - Giovana R. Teixeira
- Department of Physical Education; State University of São Paulo (UNESP); Presidente Prudente São Paulo Brazil
| | - Fábio S. Lira
- Department of Physical Education; State University of São Paulo (UNESP); Presidente Prudente São Paulo Brazil
| | - Dennys E. Cintra
- Sport Sciences Course; Faculty of Applied Sciences; State University of Campinas (UNICAMP); Limeira São Paulo Brazil
| | - Eduardo R. Ropelle
- Sport Sciences Course; Faculty of Applied Sciences; State University of Campinas (UNICAMP); Limeira São Paulo Brazil
| | - Carlos R.B. Júnior
- School of Physical Education and Sport of Ribeirão Preto; USP; Ribeirão Preto São Paulo Brazil
| | - Adelino S.R. da Silva
- Postgraduate Program in Rehabilitation and Functional Performance; Ribeirão Preto Medical School; University of São Paulo (USP); Ribeirão Preto São Paulo Brazil
- School of Physical Education and Sport of Ribeirão Preto; USP; Ribeirão Preto São Paulo Brazil
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Gawlik KI, Durbeej M. Deletion of integrin α7 subunit does not aggravate the phenotype of laminin α2 chain-deficient mice. Sci Rep 2015; 5:13916. [PMID: 26355035 PMCID: PMC4564817 DOI: 10.1038/srep13916] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Accepted: 08/10/2015] [Indexed: 11/09/2022] Open
Abstract
Laminin-211 is a major constituent of the skeletal muscle basement membrane, exerting its biological functions by binding to cell surface receptors integrin α7β1 and dystroglycan (the latter is part of the dystrophin-glycoprotein complex). The importance of these molecules for normal muscle function is underscored by the fact that their respective deficiency leads to different forms of muscular dystrophy with different severity in humans and animal models. We recently demonstrated that laminin α2 chain and members of the dystrophin-glycoprotein complex have overlapping but non-redundant roles despite being part of the same adhesion complex. To analyse whether laminin-211 and integrin α7 subunit have non-redundant functions we generated mice deficient in laminin α2 chain and integrin α7 subunit (dy3K/itga7). We show that lack of both molecules did not exacerbate the severe phenotype of laminin α2-chain deficient animals. They displayed the same weight, survival and dystrophic pattern of muscle biopsy, with similar degree of inflammation and fibrosis. These data suggest that laminin-211 and integrin α7β1 have intersecting roles in skeletal muscle.
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Affiliation(s)
- Kinga I Gawlik
- Department of Experimental Medical Science, Muscle Biology Unit, Lund University, Sweden
| | - Madeleine Durbeej
- Department of Experimental Medical Science, Muscle Biology Unit, Lund University, Sweden
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De Lisio M, Farup J, Sukiennik RA, Clevenger N, Nallabelli J, Nelson B, Ryan K, Rahbek SK, de Paoli F, Vissing K, Boppart MD. The acute response of pericytes to muscle-damaging eccentric contraction and protein supplementation in human skeletal muscle. J Appl Physiol (1985) 2015. [PMID: 26205545 DOI: 10.1152/japplphysiol.01112.2014] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Skeletal muscle pericytes increase in quantity following eccentric exercise (ECC) and contribute to myofiber repair and adaptation in mice. The purpose of the present investigation was to examine pericyte quantity in response to muscle-damaging ECC and protein supplementation in human skeletal muscle. Male subjects were divided into protein supplement (WHY; n = 12) or isocaloric placebo (CHO; n = 12) groups and completed ECC using an isokinetic dynamometer. Supplements were consumed 3 times/day throughout the experimental time course. Biopsies were collected prior to (PRE) and 3, 24, 48, and 168 h following ECC. Reflective of the damaging protocol, integrin subunits, including α7, β1A, and β1D, increased (3.8-fold, 3.6-fold and 3.9-fold, respectively, P < 0.01) 24 h post-ECC with no difference between supplements. Pericyte quantity did not change post-ECC. WHY resulted in a small, but significant, decrease in ALP(+) pericytes when expressed as a percentage of myonuclei (CHO 6.8 ± 0.3% vs. WHY 5.8 ± 0.3%, P < 0.05) or per myofiber (CHO 0.119 ± 0.01 vs. WHY 0.098 ± 0.01, P < 0.05). The quantity of myonuclei expressing serum response factor and the number of pericytes expressing serum response factor, did not differ as a function of time post-ECC or supplement. These data demonstrate that acute muscle-damaging ECC increases α7β1 integrin content in human muscle, yet pericyte quantity is largely unaltered. Future studies should focus on the capacity for ECC to influence pericyte function, specifically paracrine factor release as a mechanism toward pericyte contribution to repair and adaptation postexercise.
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Affiliation(s)
- Michael De Lisio
- Department of Kinesiology and Community Health and Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois; and
| | - Jean Farup
- Section of Sport Science, Department of Public Health, Aarhus University, Aarhus, Denmark; and
| | - Richard A Sukiennik
- Department of Kinesiology and Community Health and Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois; and
| | - Nicole Clevenger
- Department of Kinesiology and Community Health and Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois; and
| | - Julian Nallabelli
- Department of Kinesiology and Community Health and Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois; and
| | - Brett Nelson
- Department of Kinesiology and Community Health and Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois; and
| | - Kelly Ryan
- Department of Kinesiology and Community Health and Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois; and
| | - Stine K Rahbek
- Section of Sport Science, Department of Public Health, Aarhus University, Aarhus, Denmark; and
| | - Frank de Paoli
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Kristian Vissing
- Section of Sport Science, Department of Public Health, Aarhus University, Aarhus, Denmark; and
| | - Marni D Boppart
- Department of Kinesiology and Community Health and Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois; and
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Hughes DC, Wallace MA, Baar K. Effects of aging, exercise, and disease on force transfer in skeletal muscle. Am J Physiol Endocrinol Metab 2015; 309:E1-E10. [PMID: 25968577 PMCID: PMC4490334 DOI: 10.1152/ajpendo.00095.2015] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Accepted: 05/08/2015] [Indexed: 11/22/2022]
Abstract
The loss of muscle strength and increased injury rate in aging skeletal muscle has previously been attributed to loss of muscle protein (cross-sectional area) and/or decreased neural activation. However, it is becoming clear that force transfer within and between fibers plays a significant role in this process as well. Force transfer involves a secondary matrix of proteins that align and transmit the force produced by the thick and thin filaments along muscle fibers and out to the extracellular matrix. These specialized networks of cytoskeletal proteins aid in passing force through the muscle and also serve to protect individual fibers from injury. This review discusses the cytoskeleton proteins that have been identified as playing a role in muscle force transmission, both longitudinally and laterally, and where possible highlights how disease, aging, and exercise influence the expression and function of these proteins.
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Affiliation(s)
- David C Hughes
- Department of Neurobiology, Physiology and Behavior, University of California Davis, Davis, California
| | - Marita A Wallace
- Department of Neurobiology, Physiology and Behavior, University of California Davis, Davis, California
| | - Keith Baar
- Department of Neurobiology, Physiology and Behavior, University of California Davis, Davis, California
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Hyldahl RD, Nelson B, Xin L, Welling T, Groscost L, Hubal MJ, Chipkin S, Clarkson PM, Parcell AC. Extracellular matrix remodeling and its contribution to protective adaptation following lengthening contractions in human muscle. FASEB J 2015; 29:2894-904. [PMID: 25808538 DOI: 10.1096/fj.14-266668] [Citation(s) in RCA: 93] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2014] [Accepted: 03/09/2015] [Indexed: 11/11/2022]
Abstract
This study determined the contribution of extracellular matrix (ECM) remodeling to the protective adaptation of human skeletal muscle known as the repeated-bout effect (RBE). Muscle biopsies were obtained 3 hours, 2 days, and 27 days following an initial bout (B1) of lengthening contractions (LCs) and 2 days following a repeated bout (B2) in 2 separate studies. Biopsies from the nonexercised legs served as controls. In the first study, global transcriptomic analysis indicated widespread changes in ECM structural, deadhesive, and signaling transcripts, 3 hours following LC. To determine if ECM remodeling is involved in the RBE, we conducted a second study by use of a repeated-bout paradigm. TNC immunoreactivity increased 10.8-fold following B1, was attenuated following B2, and positively correlated with LC-induced strength loss (r(2) = 0.45; P = 0.009). Expression of collagen I, III, and IV (COL1A1, COL3A1, COL4A1) transcripts was unchanged early but increased 5.7 ± 2.5-, 3.2 ± 0.9-, and 2.1 ± 0.4-fold (P < 0.05), respectively, 27 days post-B1 and were unaffected by B2. Likewise, TGF-β signaling demonstrated a delayed response following LC. Satellite cell content increased 80% (P < 0.05) 2 days post-B1 (P < 0.05), remained elevated 27 days post-B1, and was unaffected by B2. Collectively, the data suggest sequential ECM remodeling characterized by early deadhesion and delayed reconstructive activity that appear to contribute to the RBE.
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Affiliation(s)
- Robert D Hyldahl
- *Department of Exercise Sciences, Brigham Young University, Provo, Utah, USA; Department of Natural Sciences, Ohio Dominican University, Columbus, Ohio, USA; Department of Kinesiology, University of Massachusetts Amherst, Massachusetts, USA; and Department of Integrative Systems Biology, George Washington University, Washington, DC, USA
| | - Brad Nelson
- *Department of Exercise Sciences, Brigham Young University, Provo, Utah, USA; Department of Natural Sciences, Ohio Dominican University, Columbus, Ohio, USA; Department of Kinesiology, University of Massachusetts Amherst, Massachusetts, USA; and Department of Integrative Systems Biology, George Washington University, Washington, DC, USA
| | - Ling Xin
- *Department of Exercise Sciences, Brigham Young University, Provo, Utah, USA; Department of Natural Sciences, Ohio Dominican University, Columbus, Ohio, USA; Department of Kinesiology, University of Massachusetts Amherst, Massachusetts, USA; and Department of Integrative Systems Biology, George Washington University, Washington, DC, USA
| | - Tyson Welling
- *Department of Exercise Sciences, Brigham Young University, Provo, Utah, USA; Department of Natural Sciences, Ohio Dominican University, Columbus, Ohio, USA; Department of Kinesiology, University of Massachusetts Amherst, Massachusetts, USA; and Department of Integrative Systems Biology, George Washington University, Washington, DC, USA
| | - Logan Groscost
- *Department of Exercise Sciences, Brigham Young University, Provo, Utah, USA; Department of Natural Sciences, Ohio Dominican University, Columbus, Ohio, USA; Department of Kinesiology, University of Massachusetts Amherst, Massachusetts, USA; and Department of Integrative Systems Biology, George Washington University, Washington, DC, USA
| | - Monica J Hubal
- *Department of Exercise Sciences, Brigham Young University, Provo, Utah, USA; Department of Natural Sciences, Ohio Dominican University, Columbus, Ohio, USA; Department of Kinesiology, University of Massachusetts Amherst, Massachusetts, USA; and Department of Integrative Systems Biology, George Washington University, Washington, DC, USA
| | - Stuart Chipkin
- *Department of Exercise Sciences, Brigham Young University, Provo, Utah, USA; Department of Natural Sciences, Ohio Dominican University, Columbus, Ohio, USA; Department of Kinesiology, University of Massachusetts Amherst, Massachusetts, USA; and Department of Integrative Systems Biology, George Washington University, Washington, DC, USA
| | - Priscilla M Clarkson
- *Department of Exercise Sciences, Brigham Young University, Provo, Utah, USA; Department of Natural Sciences, Ohio Dominican University, Columbus, Ohio, USA; Department of Kinesiology, University of Massachusetts Amherst, Massachusetts, USA; and Department of Integrative Systems Biology, George Washington University, Washington, DC, USA
| | - Allen C Parcell
- *Department of Exercise Sciences, Brigham Young University, Provo, Utah, USA; Department of Natural Sciences, Ohio Dominican University, Columbus, Ohio, USA; Department of Kinesiology, University of Massachusetts Amherst, Massachusetts, USA; and Department of Integrative Systems Biology, George Washington University, Washington, DC, USA
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Farup J, de Paoli F, Bjerg K, Riis S, Ringgard S, Vissing K. Blood flow restricted and traditional resistance training performed to fatigue produce equal muscle hypertrophy. Scand J Med Sci Sports 2015; 25:754-63. [PMID: 25603897 DOI: 10.1111/sms.12396] [Citation(s) in RCA: 128] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/26/2014] [Indexed: 12/29/2022]
Abstract
This study investigated the hypertrophic potential of load-matched blood-flow restricted resistance training (BFR) vs free-flow traditional resistance training (low-load TRT) performed to fatigue. Ten healthy young subjects performed unilateral BFR and contralateral low-load TRT elbow flexor dumbbell curl with 40% of one repetition maximum until volitional concentric failure 3 days per week for 6 weeks. Prior to and at 3 (post-3) and 10 (post-10) days post-training, magnetic resonance imaging (MRI) was used to estimate elbow flexor muscle volume and muscle water content accumulation through training. Acute changes in muscle thickness following an early vs a late exercise bout were measured with ultrasound to determine muscle swelling during the immediate 0-48 h post-exercise. Total work was threefold lower for BFR compared with low-load TRT (P < 0.001). Both BRF and low-load TRT increased muscle volume by approximately 12% at post-3 and post-10 (P < 0.01) with no changes in MRI-determined water content. Training increased muscle thickness during the immediate 48 h post-exercise (P < 0.001) and to greater extent with BRF (P < 0.05) in the early training phase. In conclusion, BFR and low-load TRT, when performed to fatigue, produce equal muscle hypertrophy, which may partly rely on transient exercise-induced increases in muscle water content.
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Affiliation(s)
- J Farup
- Section for Sport Science, Department of Public Health, Aarhus University, Aarhus, Denmark
| | - F de Paoli
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - K Bjerg
- Section for Sport Science, Department of Public Health, Aarhus University, Aarhus, Denmark
| | - S Riis
- Section for Sport Science, Department of Public Health, Aarhus University, Aarhus, Denmark
| | - S Ringgard
- MR-Research Centre, Department of Clinical Medicine, Aarhus University Hospital, Aarhus, Denmark
| | - K Vissing
- Section for Sport Science, Department of Public Health, Aarhus University, Aarhus, Denmark
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Graham ZA, Touchberry CD, Gupte AA, Bomhoff GL, Geiger PC, Gallagher PM. Changes in α7β1 integrin signaling after eccentric exercise in heat-shocked rat soleus. Muscle Nerve 2015; 51:562-8. [PMID: 24956997 DOI: 10.1002/mus.24324] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/18/2014] [Indexed: 12/16/2022]
Abstract
INTRODUCTION α7β1 integrin links the extracellular matrix to the focal adhesion (FA) in skeletal muscle and serves as a stabilizing and signal relayer. Heat shock (HS) induces expression of proteins that interact with the FA. METHODS Male Wistar rats were assigned to 1 of 3 groups: control (CON); eccentric exercise (EE); or EE+HS (HS). Soleus muscle was analyzed at 2 h and 48 h post-exercise. RESULTS The 120-kDa α7 integrin decreased in the EE and HS groups, and the 70-kDa peptide decreased in the EE group at 2 h post-exercise. Total expression of focal adhesion kinase (FAK) and RhoA were decreased in EE and HS at 2 h post-exercise. Expression of phosphorylated FAK(397) decreased in the EE group but not the HS group at 2 h post-exercise. CONCLUSIONS Long-duration EE may cause alterations in the FA in rat soleus muscle through the α7 integrin subunit and FAK.
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Affiliation(s)
- Zachary A Graham
- Applied Physiology Laboratory, Department of Health, Sport, and Exercise Sciences, University of Kansas, 101DJ Robinson Center, 1301 Sunnyside Avenue, Lawrence, Kansas, 66045, USA
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