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Egawa T, Ogawa T, Yokokawa T, Kido K, Iyama R, Zhao H, Kurogi E, Goto K, Hayashi T. Glycative stress inhibits hypertrophy and impairs cell membrane integrity in overloaded mouse skeletal muscle. J Cachexia Sarcopenia Muscle 2024; 15:883-896. [PMID: 38575520 DOI: 10.1002/jcsm.13444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Revised: 01/04/2024] [Accepted: 01/21/2024] [Indexed: 04/06/2024] Open
Abstract
BACKGROUND Glycative stress, characterized by the formation and accumulation of advanced glycation end products (AGEs) associated with protein glycation reactions, has been implicated in inducing a decline of muscle function. Although the inverse correlation between glycative stress and muscle mass and strength has been demonstrated, the underlying molecular mechanisms are not fully understood. This study aimed to elucidate how glycative stress affects the skeletal muscle, particularly the adaptive muscle response to hypertrophic stimuli and its molecular mechanism. METHODS Male C57BL/6NCr mice were randomly divided into the following two groups: the bovine serum albumin (BSA)-treated and AGE-treated groups. Mice in the AGE-treated group were intraperitoneally administered AGEs (0.5 mg/g) once daily, whereas those in the BSA-treated group received an equal amount of BSA (0.5 mg/g) as the vehicle control. After 7 days of continuous administration, the right leg plantaris muscle of mice in each group underwent functional overload treatment by synergist ablation for 7 days to induce muscle hypertrophy. In in vitro studies, cultured C2C12 myocytes were treated with AGEs (1 mg/mL) to examine cell adhesion and cell membrane permeability. RESULTS Continuous AGE administration increased the levels of fluorescent AGEs, Nε-(carboxymethyl) lysine, and methylglyoxal-derived hydroimidazolone-1 in both plasma and skeletal muscle. Plantaris muscle weight, muscle fibre cross-sectional area, protein synthesis rate, and the number of myonuclei increased with functional overload in both groups; however, the increase was significantly reduced by AGE treatment. Some muscles of AGE-treated mice were destroyed by functional overload. Proteomic analysis was performed to explore the mechanisms of muscle hypertrophy suppression and myofibre destruction by AGEs. When principal component analysis was performed on 4659 data obtained by proteomic analysis, AGE treatment was observed to affect protein expression only in functionally overloaded muscles. Enrichment analysis of the 436 proteins extracted using the K-means method further identified a group of proteins involved in cell adhesion. Consistent with this finding, dystrophin-glycoprotein complex proteins and cell adhesion-related proteins were confirmed to increase with functional overload; however, this was attenuated by AGE treatment. Additionally, the treatment of C2C12 muscle cells with AGEs inhibited their ability to adhere and increased cell membrane permeability. CONCLUSIONS This study indicates that glycative stress may be a novel pathogenic factor in skeletal muscle dysfunctions by causing loss of membrane integrity and preventing muscle mass gain.
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Affiliation(s)
- Tatsuro Egawa
- Laboratory of Health and Exercise Sciences, Graduate School of Human and Environmental Studies, Kyoto University, Kyoto, Japan
| | - Takeshi Ogawa
- Laboratory of Sports and Exercise Medicine, Graduate School of Human and Environmental Studies, Kyoto University, Kyoto, Japan
| | - Takumi Yokokawa
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
| | - Kohei Kido
- Health and Medical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Kagawa, Japan
- Institute for Physical Activity, Fukuoka University, Fukuoka, Japan
| | - Ryota Iyama
- Laboratory of Sports and Exercise Medicine, Graduate School of Human and Environmental Studies, Kyoto University, Kyoto, Japan
| | - Haiyu Zhao
- Laboratory of Sports and Exercise Medicine, Graduate School of Human and Environmental Studies, Kyoto University, Kyoto, Japan
| | - Eriko Kurogi
- Laboratory of Sports and Exercise Medicine, Graduate School of Human and Environmental Studies, Kyoto University, Kyoto, Japan
| | - Katsumasa Goto
- Laboratory of Physiology, Graduate School of Health Sciences, Toyohashi SOZO University, Toyohashi, Japan
| | - Tatsuya Hayashi
- Laboratory of Sports and Exercise Medicine, Graduate School of Human and Environmental Studies, Kyoto University, Kyoto, Japan
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Scarpelli MC, Bergamasco JGA, Godwin JS, Mesquita PHC, Chaves TS, Silva DG, Bittencourt D, Dias NF, Medalha Junior RA, Carello Filho PC, Angleri V, Costa LAR, Kavazis AN, Ugrinowitsch C, Roberts MD, Libardi CA. Resistance training-induced changes in muscle proteolysis and extracellular matrix remodeling biomarkers in the untrained and trained states. Eur J Appl Physiol 2024:10.1007/s00421-024-05484-5. [PMID: 38653795 DOI: 10.1007/s00421-024-05484-5] [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: 01/08/2024] [Accepted: 03/21/2024] [Indexed: 04/25/2024]
Abstract
PURPOSE Resistance training (RT) induces muscle growth at varying rates across RT phases, and evidence suggests that the muscle-molecular responses to training bouts become refined or attenuated in the trained state. This study examined how proteolysis-related biomarkers and extracellular matrix (ECM) remodeling factors respond to a bout of RT in the untrained (UT) and trained (T) state. METHODS Participants (19 women and 19 men) underwent 10 weeks of RT. Biopsies of vastus lateralis were collected before and after (24 h) the first (UT) and last (T) sessions. Vastus lateralis cross-sectional area (CSA) was assessed before and after the experimental period. RESULTS There were increases in muscle and type II fiber CSAs. In both the UT and T states, calpain activity was upregulated and calpain-1/-2 protein expression was downregulated from Pre to 24 h. Calpain-2 was higher in the T state. Proteasome activity and 20S proteasome protein expression were upregulated from Pre to 24 h in both the UT and T. However, proteasome activity levels were lower in the T state. The expression of poly-ubiquitinated proteins was unchanged. MMP activity was downregulated, and MMP-9 protein expression was elevated from Pre to 24 h in UT and T. Although MMP-14 protein expression was acutely unchanged, this marker was lower in T state. TIMP-1 protein levels were reduced Pre to 24 h in UT and T, while TIMP-2 protein levels were unchanged. CONCLUSION Our results are the first to show that RT does not attenuate the acute-induced response of proteolysis and ECM remodeling-related biomarkers.
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Affiliation(s)
- Maíra C Scarpelli
- MUSCULAB - Laboratory of Neuromuscular Adaptations to Resistance Training, Department of Physical Education, Federal University of São Carlos - UFSCar, Rod. Washington Luiz, km 235 - SP 310, São Carlos, SP, 13565-905, Brazil
- School of Kinesiology, Nutrabolt Applied and Molecular Sciences Laboratory, Auburn University, 301 Wire Road, Office 286, Auburn, AL, 36849, USA
| | - João G A Bergamasco
- MUSCULAB - Laboratory of Neuromuscular Adaptations to Resistance Training, Department of Physical Education, Federal University of São Carlos - UFSCar, Rod. Washington Luiz, km 235 - SP 310, São Carlos, SP, 13565-905, Brazil
- School of Kinesiology, Nutrabolt Applied and Molecular Sciences Laboratory, Auburn University, 301 Wire Road, Office 286, Auburn, AL, 36849, USA
| | - Joshua S Godwin
- School of Kinesiology, Nutrabolt Applied and Molecular Sciences Laboratory, Auburn University, 301 Wire Road, Office 286, Auburn, AL, 36849, USA
| | - Paulo H C Mesquita
- School of Kinesiology, Nutrabolt Applied and Molecular Sciences Laboratory, Auburn University, 301 Wire Road, Office 286, Auburn, AL, 36849, USA
| | - Talisson S Chaves
- MUSCULAB - Laboratory of Neuromuscular Adaptations to Resistance Training, Department of Physical Education, Federal University of São Carlos - UFSCar, Rod. Washington Luiz, km 235 - SP 310, São Carlos, SP, 13565-905, Brazil
| | - Deivid G Silva
- MUSCULAB - Laboratory of Neuromuscular Adaptations to Resistance Training, Department of Physical Education, Federal University of São Carlos - UFSCar, Rod. Washington Luiz, km 235 - SP 310, São Carlos, SP, 13565-905, Brazil
| | - Diego Bittencourt
- MUSCULAB - Laboratory of Neuromuscular Adaptations to Resistance Training, Department of Physical Education, Federal University of São Carlos - UFSCar, Rod. Washington Luiz, km 235 - SP 310, São Carlos, SP, 13565-905, Brazil
| | - Nathalia F Dias
- MUSCULAB - Laboratory of Neuromuscular Adaptations to Resistance Training, Department of Physical Education, Federal University of São Carlos - UFSCar, Rod. Washington Luiz, km 235 - SP 310, São Carlos, SP, 13565-905, Brazil
| | - Ricardo A Medalha Junior
- MUSCULAB - Laboratory of Neuromuscular Adaptations to Resistance Training, Department of Physical Education, Federal University of São Carlos - UFSCar, Rod. Washington Luiz, km 235 - SP 310, São Carlos, SP, 13565-905, Brazil
| | - Paulo C Carello Filho
- MUSCULAB - Laboratory of Neuromuscular Adaptations to Resistance Training, Department of Physical Education, Federal University of São Carlos - UFSCar, Rod. Washington Luiz, km 235 - SP 310, São Carlos, SP, 13565-905, Brazil
| | - Vitor Angleri
- MUSCULAB - Laboratory of Neuromuscular Adaptations to Resistance Training, Department of Physical Education, Federal University of São Carlos - UFSCar, Rod. Washington Luiz, km 235 - SP 310, São Carlos, SP, 13565-905, Brazil
| | - Luiz A R Costa
- School of Physical Education and Sport, University of São Paulo - USP, São Paulo, SP, Brazil
| | - Andreas N Kavazis
- School of Kinesiology, Nutrabolt Applied and Molecular Sciences Laboratory, Auburn University, 301 Wire Road, Office 286, Auburn, AL, 36849, USA
| | - Carlos Ugrinowitsch
- School of Physical Education and Sport, University of São Paulo - USP, São Paulo, SP, Brazil
- Department of Health Sciences and Human Performance, University of Tampa, Tampa, FL, USA
| | - Michael D Roberts
- School of Kinesiology, Nutrabolt Applied and Molecular Sciences Laboratory, Auburn University, 301 Wire Road, Office 286, Auburn, AL, 36849, USA.
| | - Cleiton A Libardi
- MUSCULAB - Laboratory of Neuromuscular Adaptations to Resistance Training, Department of Physical Education, Federal University of São Carlos - UFSCar, Rod. Washington Luiz, km 235 - SP 310, São Carlos, SP, 13565-905, Brazil.
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McLendon JM, Zhang X, Stein CS, Baehr LM, Bodine SC, Boudreau RL. A Specialized Centrosome-Proteasome Axis Mediates Proteostasis and Influences Cardiac Stress through Txlnb. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.12.580020. [PMID: 38405715 PMCID: PMC10888801 DOI: 10.1101/2024.02.12.580020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/27/2024]
Abstract
Background Centrosomes localize to perinuclear foci where they serve multifunctional roles, arranging the microtubule organizing center (MTOC) and anchoring ubiquitin-proteasome system (UPS) machinery. In mature cardiomyocytes, centrosomal proteins redistribute into a specialized perinuclear cage-like structure, and a potential centrosome-UPS interface has not been studied. Taxilin-beta (Txlnb), a cardiomyocyte-enriched protein, belongs to a family of centrosome adapter proteins implicated in protein quality control. We hypothesize that Txlnb plays a key role in centrosomal-proteasomal crosstalk in cardiomyocytes. Methods Integrative bioinformatics assessed centrosomal gene dysregulation in failing hearts. Txlnb gain/loss-of-function studies were conducted in cultured cardiomyocytes and mice. Txlnb's role in cardiac proteotoxicity and hypertrophy was examined using CryAB-R120G mice and transverse aortic constriction (TAC), respectively. Molecular modeling investigated Txlnb structure/function. Results Human failing hearts show consistent dysregulation of many centrosome-associated genes, alongside UPS-related genes. Txlnb emerged as a candidate regulator of cardiomyocyte proteostasis that localizes to the perinuclear centrosomal compartment. Txlnb's interactome strongly supports its involvement in cytoskeletal, microtubule, and UPS processes, particularly centrosome-related functions. Overexpressing Txlnb in cardiomyocytes reduced ubiquitinated protein accumulation and enhanced proteasome activity during hypertrophy. Txlnb-knockout (KO) mouse hearts exhibit proteasomal insufficiency and altered cardiac growth, evidenced by ubiquitinated protein accumulation, decreased 26Sβ5 proteasome activity, and lower mass with age. In Cryab-R120G mice, Txlnb loss worsened heart failure, causing lower ejection fractions. After TAC, Txlnb-KO mice also showed reduced ejection fraction, increased heart mass, and elevated ubiquitinated protein accumulation. Investigations into the molecular mechanisms revealed that Txlnb-KO did not affect proteasomal subunit expression but led to the upregulation of Txlna and several centrosomal proteins (Cep63, Ofd1, and Tubg) suggesting altered centrosomal dynamics. Structural predictions support Txlnb's role as a specialized centrosomal-adapter protein bridging centrosomes with proteasomes, confirmed by microtubule-dependent perinuclear localization. Conclusions Together, these data provide initial evidence connecting Txlnb to cardiac proteostasis, hinting at the potential importance of functional bridging between specialized centrosomes and UPS in cardiomyocytes.
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Larson KR, Jayakrishnan D, Soto Sauza KA, Goodson ML, Chaffin AT, Davidyan A, Pathak S, Fang Y, Gonzalez Magaña D, Miller BF, Ryan KK. FGF21 Induces Skeletal Muscle Atrophy and Increases Amino Acids in Female Mice: A Potential Role for Glucocorticoids. Endocrinology 2024; 165:bqae004. [PMID: 38244215 PMCID: PMC10849119 DOI: 10.1210/endocr/bqae004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 09/27/2023] [Accepted: 01/18/2024] [Indexed: 01/22/2024]
Abstract
Fibroblast growth factor-21 (FGF21) is an intercellular signaling molecule secreted by metabolic organs, including skeletal muscle, in response to intracellular stress. FGF21 crosses the blood-brain barrier and acts via the nervous system to coordinate aspects of the adaptive starvation response, including increased lipolysis, gluconeogenesis, fatty acid oxidation, and activation of the hypothalamic-pituitary-adrenocortical (HPA) axis. Given its beneficial effects for hepatic lipid metabolism, pharmaceutical FGF21 analogues are used in clinical trials treatment of fatty liver disease. We predicted pharmacologic treatment with FGF21 increases HPA axis activity and skeletal muscle glucocorticoid signaling and induces skeletal muscle atrophy in mice. Here we found a short course of systemic FGF21 treatment decreased muscle protein synthesis and reduced tibialis anterior weight; this was driven primarily by its effect in female mice. Similarly, intracerebroventricular FGF21 reduced tibialis anterior muscle fiber cross-sectional area; this was more apparent among female mice than male littermates. In agreement with the reduced muscle mass, the topmost enriched metabolic pathways in plasma collected from FGF21-treated females were related to amino acid metabolism, and the relative abundance of plasma proteinogenic amino acids was increased up to 3-fold. FGF21 treatment increased hypothalamic Crh mRNA, plasma corticosterone, and adrenal weight, and increased expression of glucocorticoid receptor target genes known to reduce muscle protein synthesis and/or promote degradation. Given the proposed use of FGF21 analogues for the treatment of metabolic disease, the study is both physiologically relevant and may have important clinical implications.
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Affiliation(s)
- Karlton R Larson
- Department of Neurobiology, Physiology, and Behavior, College of Biological Sciences, University of California Davis, Davis, CA 95616, USA
| | - Devi Jayakrishnan
- Department of Neurobiology, Physiology, and Behavior, College of Biological Sciences, University of California Davis, Davis, CA 95616, USA
| | - Karla A Soto Sauza
- Department of Neurobiology, Physiology, and Behavior, College of Biological Sciences, University of California Davis, Davis, CA 95616, USA
| | - Michael L Goodson
- Department of Neurobiology, Physiology, and Behavior, College of Biological Sciences, University of California Davis, Davis, CA 95616, USA
| | - Aki T Chaffin
- Department of Neurobiology, Physiology, and Behavior, College of Biological Sciences, University of California Davis, Davis, CA 95616, USA
| | - Arik Davidyan
- Department of Neurobiology, Physiology, and Behavior, College of Biological Sciences, University of California Davis, Davis, CA 95616, USA
- Department of Biological Sciences, California State University Sacramento, Sacramento, CA 95819, USA
| | - Suraj Pathak
- Department of Neurobiology, Physiology, and Behavior, College of Biological Sciences, University of California Davis, Davis, CA 95616, USA
| | - Yanbin Fang
- Department of Neurobiology, Physiology, and Behavior, College of Biological Sciences, University of California Davis, Davis, CA 95616, USA
| | - Diego Gonzalez Magaña
- Department of Neurobiology, Physiology, and Behavior, College of Biological Sciences, University of California Davis, Davis, CA 95616, USA
| | - Benjamin F Miller
- Aging & Metabolism Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA
- Oklahoma City Veterans Affairs Medical Center, Oklahoma City, OK 73104, USA
| | - Karen K Ryan
- Department of Neurobiology, Physiology, and Behavior, College of Biological Sciences, University of California Davis, Davis, CA 95616, USA
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Hughes DC, Goodman CA, Baehr LM, Gregorevic P, Bodine SC. A critical discussion on the relationship between E3 ubiquitin ligases, protein degradation, and skeletal muscle wasting: it's not that simple. Am J Physiol Cell Physiol 2023; 325:C1567-C1582. [PMID: 37955121 PMCID: PMC10861180 DOI: 10.1152/ajpcell.00457.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 11/07/2023] [Accepted: 11/07/2023] [Indexed: 11/14/2023]
Abstract
Ubiquitination is an important post-translational modification (PTM) for protein substrates, whereby ubiquitin is added to proteins through the coordinated activity of activating (E1), ubiquitin-conjugating (E2), and ubiquitin ligase (E3) enzymes. The E3s provide key functions in the recognition of specific protein substrates to be ubiquitinated and aid in determining their proteolytic or nonproteolytic fates, which has led to their study as indicators of altered cellular processes. MuRF1 and MAFbx/Atrogin-1 were two of the first E3 ubiquitin ligases identified as being upregulated in a range of different skeletal muscle atrophy models. Since their discovery, the expression of these E3 ubiquitin ligases has often been studied as a surrogate measure of changes to bulk protein degradation rates. However, emerging evidence has highlighted the dynamic and complex regulation of the ubiquitin proteasome system (UPS) in skeletal muscle and demonstrated that protein ubiquitination is not necessarily equivalent to protein degradation. These observations highlight the potential challenges of quantifying E3 ubiquitin ligases as markers of protein degradation rates or ubiquitin proteasome system (UPS) activation. This perspective examines the usefulness of monitoring E3 ubiquitin ligases for determining specific or bulk protein degradation rates in the settings of skeletal muscle atrophy. Specific questions that remain unanswered within the skeletal muscle atrophy field are also identified, to encourage the pursuit of new research that will be critical in moving forward our understanding of the molecular mechanisms that govern protein function and degradation in muscle.
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Affiliation(s)
- David C Hughes
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma, United States
| | - Craig A Goodman
- Centre for Muscle Research (CMR), Department of Anatomy and Physiology, The University of Melbourne, Parkville, Victoria, Australia
| | - Leslie M Baehr
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma, United States
| | - Paul Gregorevic
- Centre for Muscle Research (CMR), Department of Anatomy and Physiology, The University of Melbourne, Parkville, Victoria, Australia
- Department of Neurology, The University of Washington School of Medicine, Seattle, Washington, United States
| | - Sue C Bodine
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma, United States
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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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Tokuda N, Watanabe D, Naito A, Yamauchi N, Ashida Y, Cheng AJ, Yamada T. Intrinsic contractile dysfunction due to impaired sarcoplasmic reticulum Ca 2+ release in compensatory hypertrophied muscle fibers following synergist ablation. Am J Physiol Cell Physiol 2023; 325:C599-C612. [PMID: 37486068 DOI: 10.1152/ajpcell.00127.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Revised: 07/12/2023] [Accepted: 07/12/2023] [Indexed: 07/25/2023]
Abstract
Synergist ablation (SA) is an experimental procedure for the induction of hypertrophy. However, SA causes a decrease in specific force (i.e., force per cross-sectional area), likely due to excessive muscle use. Here, we investigated the mechanisms behind the SA-induced intrinsic contractile dysfunction, especially focusing on the excitation-contraction (EC) coupling. Male Wistar rats had unilateral surgical ablation of gastrocnemius and soleus muscles to induce compensatory hypertrophy in the plantaris muscles. Two weeks after SA, plantaris muscle was dissected from each animal and used for later analyses. SA significantly increased the mean fiber cross-sectional area (+18%). On the other hand, the ratio of depolarization-induced force to the maximum Ca2+-activated specific force, an indicator of sarcoplasmic reticulum (SR) Ca2+ release, was markedly reduced in mechanically skinned fibers from the SA group (-51%). These functional defects were accompanied by an extensive fragmentation of the SR Ca2+ release channel, the ryanodine receptor 1 (RyR1), and a decrease in the amount of other triad proteins (i.e., DHPR, STAC3, and junctophilin1). SA treatment also caused activation of calpain-1 and increased the amount of NADPH oxidase 2, endoplasmic reticulum (ER) stress proteins (i.e., Grp78, Grp94, PDI, and Ero1), and lipid peroxidation [i.e., 4-hydroxynonenal (4-HNE)] in SA-treated muscles. Our findings show that SA causes skeletal muscle weakness due to impaired EC coupling. This is likely to be induced by Ca2+-dependent degradation of triad proteins, which may result from Ca2+ leak from fragmented RyR1 triggered by increased oxidative stress.NEW & NOTEWORTHY Synergist ablation (SA) has widely been used to understand the mechanisms behind skeletal muscle hypertrophy. However, compensatory hypertrophied muscles display intrinsic contractile dysfunction, i.e., a hallmark of overuse. Here, we demonstrate that SA-induced compensatory hypertrophy is accompanied by muscle weakness due to impaired sarcoplasmic reticulum Ca2+ release. This dysfunction may be caused by the degradation of triad proteins due to the reciprocal amplification of reactive oxygen species and Ca2+ signaling at the junctional space microdomain.
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Affiliation(s)
- Nao Tokuda
- Graduate School of Health Sciences, Sapporo Medical University, Sapporo, Japan
| | - Daiki Watanabe
- Graduate School of Sport and Health Sciences, Osaka University of Health and Sport Sciences, Osaka, Japan
| | - Azuma Naito
- Graduate School of Health Sciences, Sapporo Medical University, Sapporo, Japan
| | - Nao Yamauchi
- Graduate School of Health Sciences, Sapporo Medical University, Sapporo, Japan
| | - Yuki Ashida
- Graduate School of Health Sciences, Sapporo Medical University, Sapporo, Japan
- The Japan Society for the Promotion of Science (JSPS), Tokyo, Japan
| | - Arthur J Cheng
- School of Kinesiology and Health Sciences, York University, Toronto, Ontario, Canada
| | - Takashi Yamada
- Graduate School of Health Sciences, Sapporo Medical University, Sapporo, Japan
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Emerging Mechanisms of Skeletal Muscle Homeostasis and Cachexia: The SUMO Perspective. Cells 2023; 12:cells12040644. [PMID: 36831310 PMCID: PMC9953977 DOI: 10.3390/cells12040644] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 02/10/2023] [Accepted: 02/14/2023] [Indexed: 02/19/2023] Open
Abstract
Mobility is an intrinsic feature of the animal kingdom that stimulates evolutionary processes and determines the biological success of animals. Skeletal muscle is the primary driver of voluntary movements. Besides, skeletal muscles have an immense impact on regulating glucose, amino acid, and lipid homeostasis. Muscle atrophy/wasting conditions are accompanied by a drastic effect on muscle function and disrupt steady-state muscle physiology. Cachexia is a complex multifactorial muscle wasting syndrome characterized by extreme loss of skeletal muscle mass, resulting in a dramatic decrease in life quality and reported mortality in more than 30% of patients with advanced cancers. The lack of directed treatments to prevent or relieve muscle loss indicates our inadequate knowledge of molecular mechanisms involved in muscle cell organization and the molecular etiology of cancer-induced cachexia (CIC). This review highlights the latest knowledge of regulatory mechanisms involved in maintaining muscle function and their deregulation in wasting syndromes, particularly in cachexia. Recently, protein posttranslational modification by the small ubiquitin-like modifier (SUMO) has emerged as a key regulatory mechanism of protein function with implications for different aspects of cell physiology and diseases. We also review an atypical association of SUMO-mediated pathways in this context and deliberate on potential treatment strategies to alleviate muscle atrophy.
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Ubiquitin Ligases in Longevity and Aging Skeletal Muscle. Int J Mol Sci 2022; 23:ijms23147602. [PMID: 35886949 PMCID: PMC9315556 DOI: 10.3390/ijms23147602] [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: 06/22/2022] [Revised: 07/07/2022] [Accepted: 07/08/2022] [Indexed: 12/07/2022] Open
Abstract
The development and prevalence of diseases associated with aging presents a global health burden on society. One hallmark of aging is the loss of proteostasis which is caused in part by alterations to the ubiquitin-proteasome system (UPS) and lysosome-autophagy system leading to impaired function and maintenance of mass in tissues such as skeletal muscle. In the instance of skeletal muscle, the impairment of function occurs early in the aging process and is dependent on proteostatic mechanisms. The UPS plays a pivotal role in degradation of misfolded and aggregated proteins. For the purpose of this review, we will discuss the role of the UPS system in the context of age-related loss of muscle mass and function. We highlight the significant role that E3 ubiquitin ligases play in the turnover of key components (e.g., mitochondria and neuromuscular junction) essential to skeletal muscle function and the influence of aging. In addition, we will briefly discuss the contribution of the UPS system to lifespan. By understanding the UPS system as part of the proteostasis network in age-related diseases and disorders such as sarcopenia, new discoveries can be made and new interventions can be developed which will preserve muscle function and maintain quality of life with advancing age.
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10
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Horwath O, Moberg M, Hirschberg AL, Ekblom B, Apró W. Molecular Regulators of Muscle Mass and Mitochondrial Remodeling Are Not Influenced by Testosterone Administration in Young Women. Front Endocrinol (Lausanne) 2022; 13:874748. [PMID: 35498440 PMCID: PMC9046720 DOI: 10.3389/fendo.2022.874748] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/12/2022] [Accepted: 03/18/2022] [Indexed: 01/07/2023] Open
Abstract
Testosterone (T) administration has previously been shown to improve muscle size and oxidative capacity. However, the molecular mechanisms underlying these adaptations in human skeletal muscle remain to be determined. Here, we examined the effect of moderate-dose T administration on molecular regulators of muscle protein turnover and mitochondrial remodeling in muscle samples collected from young women. Forty-eight healthy, physically active, young women (28 ± 4 years) were assigned in a random double-blind fashion to receive either T (10 mg/day) or placebo for 10-weeks. Muscle biopsies collected before and after the intervention period were divided into sub-cellular fractions and total protein levels of molecular regulators of muscle protein turnover and mitochondrial remodeling were analyzed using Western blotting. T administration had no effect on androgen receptor or 5α-reductase levels, nor on proteins involved in the mTORC1-signaling pathway (mTOR, S6K1, eEF2 and RPS6). Neither did it affect the abundance of proteins associated with proteasomal protein degradation (MAFbx, MuRF-1 and UBR5) and autophagy-lysosomal degradation (AMPK, ULK1 and p62). T administration also had no effect on proteins in the mitochondria enriched fraction regulating mitophagy (Beclin, BNIP3, LC3B-I, LC3B-II and LC3B-II/I ratio) and morphology (Mitofilin), and it did not alter the expression of mitochondrial fission- (FIS1 and DRP1) or fusion factors (OPA1 and MFN2). In summary, these data indicate that improvements in muscle size and oxidative capacity in young women in response to moderate-dose T administration cannot be explained by alterations in total expression of molecular factors known to regulate muscle protein turnover or mitochondrial remodeling.
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Affiliation(s)
- Oscar Horwath
- Department of Physiology, Nutrition and Biomechanics, Åstrand Laboratory, Swedish School of Sport and Health Sciences, Stockholm, Sweden
- *Correspondence: Oscar Horwath,
| | - Marcus Moberg
- Department of Physiology, Nutrition and Biomechanics, Åstrand Laboratory, Swedish School of Sport and Health Sciences, Stockholm, Sweden
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Angelica Lindén Hirschberg
- Department of Women´s and Children´s Health, Division of Neonatology, Obstetrics and Gynaecology, Karolinska Institutet, Stockholm, Sweden
- Department of Gynaecology and Reproductive Medicine, Karolinska University Hospital, Stockholm, Sweden
| | - Björn Ekblom
- Department of Physiology, Nutrition and Biomechanics, Åstrand Laboratory, Swedish School of Sport and Health Sciences, Stockholm, Sweden
| | - William Apró
- Department of Physiology, Nutrition and Biomechanics, Åstrand Laboratory, Swedish School of Sport and Health Sciences, Stockholm, Sweden
- Department of Clinical Science, Intervention and Technology, Karolinska Institutet, Stockholm, Sweden
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11
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Borg ML, Massart J, De Castro Barbosa T, Archilla-Ortega A, Smith JAB, Lanner JT, Alsina-Fernandez J, Yaden B, Culver AE, Karlsson HKR, Brozinick JT, Zierath JR. Modified UCN2 peptide treatment improves skeletal muscle mass and function in mouse models of obesity-induced insulin resistance. J Cachexia Sarcopenia Muscle 2021; 12:1232-1248. [PMID: 34342159 PMCID: PMC8517345 DOI: 10.1002/jcsm.12746] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 05/25/2021] [Accepted: 06/08/2021] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Type 2 diabetes and obesity are often seen concurrently with skeletal muscle wasting, leading to further derangements in function and metabolism. Muscle wasting remains an unmet need for metabolic disease, and new approaches are warranted. The neuropeptide urocortin 2 (UCN2) and its receptor corticotropin releasing factor receptor 2 (CRHR2) are highly expressed in skeletal muscle and play a role in regulating energy balance, glucose metabolism, and muscle mass. The aim of this study was to investigate the effects of modified UCN2 peptides as a pharmaceutical therapy to counteract the loss of skeletal muscle mass associated with obesity and casting immobilization. METHODS High-fat-fed mice (C57Bl/6J; 26 weeks old) and ob/ob mice (11 weeks old) were injected daily with a PEGylated (Compound A) and non-PEGylated (Compound B) modified human UCN2 at 0.3 mg/kg subcutaneously for 14 days. A separate group of chow-fed C57Bl/6J mice (12 weeks old) was subjected to hindlimb cast immobilization and, after 1 week, received daily injections with Compound A. In vivo functional tests were performed to measure protein synthesis rates and skeletal muscle function. Ex vivo functional and molecular tests were performed to measure contractile force and signal transduction of catabolic and anabolic pathways in skeletal muscle. RESULTS Skeletal muscles (extensor digitorum longus, soleus, and tibialis anterior) from high-fat-fed mice treated with Compound A were ~14% heavier than muscles from vehicle-treated mice. Chronic treatment with modified UCN2 peptides altered the expression of structural genes and transcription factors in skeletal muscle in high-fat diet-induced obesity including down-regulation of Trim63 and up-regulation of Nr4a2 and Igf1 (P < 0.05 vs. vehicle). Signal transduction via both catabolic and anabolic pathways was increased in tibialis anterior muscle, with increased phosphorylation of ribosomal protein S6 at Ser235/236 , FOXO1 at Ser256 , and ULK1 at Ser317 , suggesting that UCN2 treatment modulates protein synthesis and degradation pathways (P < 0.05 vs. vehicle). Acutely, a single injection of Compound A in drug-naïve mice had no effect on the rate of protein synthesis in skeletal muscle, as measured via the surface sensing of translation method, while the expression of Nr4a3 and Ppargc1a4 was increased (P < 0.05 vs. vehicle). Compound A treatment prevented the loss of force production from disuse due to casting. Compound B treatment increased time to fatigue during ex vivo contractions of fast-twitch extensor digitorum longus muscle. Compound A and B treatment increased lean mass and rates of skeletal muscle protein synthesis in ob/ob mice. CONCLUSIONS Modified human UCN2 is a pharmacological candidate for the prevention of the loss of skeletal muscle mass associated with obesity and immobilization.
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Affiliation(s)
- Melissa L Borg
- Department of Physiology and Pharmacology, Section for Integrative Physiology, Karolinska Institutet, Stockholm, Sweden
| | - Julie Massart
- Department of Molecular Medicine and Surgery, Section for Integrative Physiology, Karolinska Institutet, Stockholm, Sweden
| | - Thais De Castro Barbosa
- Department of Physiology and Pharmacology, Section for Integrative Physiology, Karolinska Institutet, Stockholm, Sweden
| | - Adrià Archilla-Ortega
- Department of Physiology and Pharmacology, Section for Integrative Physiology, Karolinska Institutet, Stockholm, Sweden
| | - Jonathon A B Smith
- Department of Physiology and Pharmacology, Section for Integrative Physiology, Karolinska Institutet, Stockholm, Sweden
| | - Johanna T Lanner
- Department of Physiology and Pharmacology, Section for Molecular Muscle Physiology and Pathophysiology, Karolinska Institutet, Stockholm, Sweden
| | | | - Benjamin Yaden
- Lilly Research Laboratories, Division of Eli Lilly and Company, Indianapolis, IN, USA
| | - Alexander E Culver
- Lilly Research Laboratories, Division of Eli Lilly and Company, Indianapolis, IN, USA
| | - Håkan K R Karlsson
- Department of Molecular Medicine and Surgery, Section for Integrative Physiology, Karolinska Institutet, Stockholm, Sweden
| | - Joseph T Brozinick
- Lilly Research Laboratories, Division of Eli Lilly and Company, Indianapolis, IN, USA
| | - Juleen R Zierath
- Department of Physiology and Pharmacology, Section for Integrative Physiology, Karolinska Institutet, Stockholm, Sweden.,Department of Molecular Medicine and Surgery, Section for Integrative Physiology, Karolinska Institutet, Stockholm, Sweden
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12
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Turner DC, Gorski PP, Seaborne RA, Viggars M, Murphy M, Jarvis JC, Martin NR, Stewart CE, Sharples AP. Mechanical loading of bioengineered skeletal muscle in vitro recapitulates gene expression signatures of resistance exercise in vivo. J Cell Physiol 2021; 236:6534-6547. [PMID: 33586196 PMCID: PMC8653897 DOI: 10.1002/jcp.30328] [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] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Revised: 01/17/2021] [Accepted: 02/03/2021] [Indexed: 11/10/2022]
Abstract
Understanding the role of mechanical loading and exercise in skeletal muscle (SkM) is paramount for delineating the molecular mechanisms that govern changes in muscle mass. However, it is unknown whether loading of bioengineered SkM in vitro adequately recapitulates the molecular responses observed after resistance exercise (RE) in vivo. To address this, the transcriptional and epigenetic (DNA methylation) responses were compared after mechanical loading in bioengineered SkM in vitro and after RE in vivo. Specifically, genes known to be upregulated/hypomethylated after RE in humans were analyzed. Ninety-three percent of these genes demonstrated similar changes in gene expression post-loading in the bioengineered muscle when compared to acute RE in humans. Furthermore, similar differences in gene expression were observed between loaded bioengineered SkM and after programmed RT in rat SkM tissue. Hypomethylation occurred for only one of the genes analysed (GRIK2) post-loading in bioengineered SkM. To further validate these findings, DNA methylation and mRNA expression of known hypomethylated and upregulated genes post-acute RE in humans were also analyzed at 0.5, 3, and 24 h post-loading in bioengineered muscle. The largest changes in gene expression occurred at 3 h, whereby 82% and 91% of genes responded similarly when compared to human and rodent SkM respectively. DNA methylation of only a small proportion of genes analyzed (TRAF1, MSN, and CTTN) significantly increased post-loading in bioengineered SkM alone. Overall, mechanical loading of bioengineered SkM in vitro recapitulates the gene expression profile of human and rodent SkM after RE in vivo. Although some genes demonstrated differential DNA methylation post-loading in bioengineered SkM, such changes across the majority of genes analyzed did not closely mimic the epigenetic response to acute-RE in humans.
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Affiliation(s)
- Daniel C. Turner
- Institute for Science and Technology in Medicine (ISTM), School of Pharmacy and BioengineeringKeele UniversityStaffordshireUK
- Stem Cells, Ageing and Molecular Physiology Unit (SCAMP), Exercise Metabolism and Adaptation Research Group (EMARG), Research Institute for Sport and Exercise Sciences (RISES)Liverpool John Moores UniversityLiverpoolUK
- Randall Centre for Cell and Molecular Biophysics, School of Basic and Medical BiosciencesKing's College LondonLondonUK
| | - Piotr P. Gorski
- Institute for Science and Technology in Medicine (ISTM), School of Pharmacy and BioengineeringKeele UniversityStaffordshireUK
- Institute for Physical PerformanceNorwegian School of Sport Sciences (NiH)OsloNorway
| | - Robert A. Seaborne
- Stem Cells, Ageing and Molecular Physiology Unit (SCAMP), Exercise Metabolism and Adaptation Research Group (EMARG), Research Institute for Sport and Exercise Sciences (RISES)Liverpool John Moores UniversityLiverpoolUK
- Center for Genomics and Child Health, Blizard Institute, Barts and the London School of Medicine and DentistryQueen Mary University of LondonLondonUK
| | - Mark Viggars
- Stem Cells, Ageing and Molecular Physiology Unit (SCAMP), Exercise Metabolism and Adaptation Research Group (EMARG), Research Institute for Sport and Exercise Sciences (RISES)Liverpool John Moores UniversityLiverpoolUK
| | - Mark Murphy
- School of Pharmacy and Biomolecular SciencesLiverpool John Moores UniversityLiverpoolUK
| | - Jonathan C. Jarvis
- Stem Cells, Ageing and Molecular Physiology Unit (SCAMP), Exercise Metabolism and Adaptation Research Group (EMARG), Research Institute for Sport and Exercise Sciences (RISES)Liverpool John Moores UniversityLiverpoolUK
| | - Neil R.W. Martin
- School of Sport, Exercise and Health SciencesLoughborough UniversityLoughboroughUK
| | - Claire E. Stewart
- Stem Cells, Ageing and Molecular Physiology Unit (SCAMP), Exercise Metabolism and Adaptation Research Group (EMARG), Research Institute for Sport and Exercise Sciences (RISES)Liverpool John Moores UniversityLiverpoolUK
| | - Adam P. Sharples
- Institute for Physical PerformanceNorwegian School of Sport Sciences (NiH)OsloNorway
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13
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Vann CG, Haun CT, Osburn SC, Romero MA, Roberson PA, Mumford PW, Mobley CB, Holmes HM, Fox CD, Young KC, Roberts MD. Molecular Differences in Skeletal Muscle After 1 Week of Active vs. Passive Recovery From High-Volume Resistance Training. J Strength Cond Res 2021; 35:2102-2113. [PMID: 34138821 DOI: 10.1519/jsc.0000000000004071] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
ABSTRACT Vann, CG, Haun, CT, Osburn, SC, Romero, MA, Roberson, PA, Mumford, PW, Mobley, CB, Holmes, HM, Fox, CD, Young, KC, and Roberts, MD. Molecular differences in skeletal muscle after 1 week of active vs. passive recovery from high-volume resistance training. J Strength Cond Res 35(8): 2102-2113, 2021-Numerous studies have evaluated how deloading after resistance training (RT) affects strength and power outcomes. However, the molecular adaptations that occur after deload periods remain understudied. Trained, college-aged men (n = 30) performed 6 weeks of whole-body RT starting at 10 sets of 10 repetitions per exercise per week and finishing at 32 sets of 10 repetitions per exercise per week. After this period, subjects performed either active (AR; n = 16) or passive recovery (PR; n = 14) for 1 week where AR completed ∼15% of the week 6 training volume and PR ceased training. Variables related to body composition and recovery examined before RT (PRE), after 6 weeks of RT (POST), and after the 1-week recovery period (DL). Vastus lateralis (VL) muscle biopsies and blood samples were collected at each timepoint, and various biochemical and histological assays were performed. Group × time interactions (p < 0.05) existed for skeletal muscle myosin heavy chain (MHC)-IIa mRNA (AR > PR at POST and DL) and 20S proteasome activity (post-hoc tests revealed no significance in groups over time). Time effects (P < 0.05) existed for total mood disturbance and serum creatine kinase and mechano growth factor mRNA (POST > PRE &D L), VL pressure to pain threshold and MHC-IIx mRNA (PRE&DL > POST), Atrogin-1 and MuRF-1 mRNA (PRE < POST < DL), MHC-I mRNA (PRE < POST & DL), myostatin mRNA (PRE & POST < DL), and mechanistic target of rapamycin (PRE > POST & DL). No interactions or time effects were observed for barbell squat velocity, various hormones, histological metrics, polyubiquitinated proteins, or phosphorylated/pan protein levels of 4E-BP1, p70S6k, and AMPK. One week of AR after a high-volume training block instigates marginal molecular differences in skeletal muscle relative to PR. From a practical standpoint, however, both paradigms elicited largely similar responses.
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Affiliation(s)
| | - Cody T Haun
- Department of Exercise Science, LaGrange College, Lagrange, Georgia
| | | | - Matthew A Romero
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, Los Angeles, California
| | - Paul A Roberson
- Department of Cellular and Molecular Physiology, College of Medicine, The Pennsylvania State University, Hershey, Pennsylvania
| | - Petey W Mumford
- Department of Exercise Science, Lindenwood University, St. Charles, Missouri
| | - C Brooks Mobley
- Department of Physiology, University of Kentucky, Lexington, Kentucky; and
| | | | - Carlton D Fox
- School of Kinesiology, Auburn University, Auburn, Alabama
| | - Kaelin C Young
- School of Kinesiology, Auburn University, Auburn, Alabama
- Edward Via College of Osteopathic Medicine-Auburn Campus, Auburn, Alabama
| | - Michael D Roberts
- School of Kinesiology, Auburn University, Auburn, Alabama
- Edward Via College of Osteopathic Medicine-Auburn Campus, Auburn, Alabama
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14
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Nishimura Y, Musa I, Holm L, Lai YC. Recent advances in measuring and understanding the regulation of exercise-mediated protein degradation in skeletal muscle. Am J Physiol Cell Physiol 2021; 321:C276-C287. [PMID: 34038244 DOI: 10.1152/ajpcell.00115.2021] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Skeletal muscle protein turnover plays a crucial role in controlling muscle mass and protein quality control, including sarcomeric (structural and contractile) proteins. Protein turnover is a dynamic and continual process of protein synthesis and degradation. The ubiquitin proteasome system (UPS) is a key degradative system for protein degradation and protein quality control in skeletal muscle. UPS-mediated protein quality control is known to be impaired in aging and diseases. Exercise is a well-recognized, nonpharmacological approach to promote muscle protein turnover rates. Over the past decades, we have acquired substantial knowledge of molecular mechanisms of muscle protein synthesis after exercise. However, there have been considerable gaps in the mechanisms of how muscle protein degradation is regulated at the molecular level. The main challenge to understand muscle protein degradation is due in part to the lack of solid stable isotope tracer methodology to measure muscle protein degradation rate. Understanding the mechanisms of UPS with the concomitant measurement of protein degradation rate in skeletal muscle will help identify novel therapeutic strategies to ameliorate impaired protein turnover and protein quality control in aging and diseases. Thus, the goal of this present review was to highlight how recent advances in the field may help improve our understanding of exercise-mediated protein degradation. We discuss 1) the emerging roles of protein phosphorylation and ubiquitylation modifications in regulating proteasome-mediated protein degradation after exercise and 2) methodological advances to measure in vivo myofibrillar protein degradation rate using stable isotope tracer methods.
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Affiliation(s)
- Yusuke Nishimura
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Ibrahim Musa
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Lars Holm
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, United Kingdom
- MRC Versus Arthritis Centre for Musculoskeletal Ageing Research, University of Birmingham, Birmingham, United Kingdom
| | - Yu-Chiang Lai
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, United Kingdom
- MRC Versus Arthritis Centre for Musculoskeletal Ageing Research, University of Birmingham, Birmingham, United Kingdom
- Institute of Metabolism and Systems Research, University of Birmingham, Birmingham, United Kingdom
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15
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Joanne P, Hovhannisyan Y, Bencze M, Daher MT, Parlakian A, Toutirais G, Gao-Li J, Lilienbaum A, Li Z, Kordeli E, Ferry A, Agbulut O. Absence of Desmin Results in Impaired Adaptive Response to Mechanical Overloading of Skeletal Muscle. Front Cell Dev Biol 2021; 9:662133. [PMID: 34336827 PMCID: PMC8320001 DOI: 10.3389/fcell.2021.662133] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Accepted: 06/23/2021] [Indexed: 11/13/2022] Open
Abstract
Background: Desmin is a muscle-specific protein belonging to the intermediate filament family. Desmin mutations are linked to skeletal muscle defects, including inherited myopathies with severe clinical manifestations. The aim of this study was to examine the role of desmin in skeletal muscle remodeling and performance gain induced by muscle mechanical overloading which mimics resistance training. Methods: Plantaris muscles were overloaded by surgical ablation of gastrocnemius and soleus muscles. The functional response of plantaris muscle to mechanical overloading in desmin-deficient mice (DesKO, n = 32) was compared to that of control mice (n = 36) after 7-days or 1-month overloading. To elucidate the molecular mechanisms implicated in the observed partial adaptive response of DesKO muscle, we examined the expression levels of genes involved in muscle growth, myogenesis, inflammation and oxidative energetic metabolism. Moreover, ultrastructure and the proteolysis pathway were explored. Results: Contrary to control, absolute maximal force did not increase in DesKO muscle following 1-month mechanical overloading. Fatigue resistance was also less increased in DesKO as compared to control muscle. Despite impaired functional adaptive response of DesKO mice to mechanical overloading, muscle weight and the number of oxidative MHC2a-positive fibers per cross-section similarly increased in both genotypes after 1-month overloading. However, mechanical overloading-elicited remodeling failed to activate a normal myogenic program after 7-days overloading, resulting in proportionally reduced activation and differentiation of muscle stem cells. Ultrastructural analysis of the plantaris muscle after 1-month overloading revealed muscle fiber damage in DesKO, as indicated by the loss of sarcomere integrity and mitochondrial abnormalities. Moreover, the observed accumulation of autophagosomes and lysosomes in DesKO muscle fibers could indicate a blockage of autophagy. To address this issue, two main proteolysis pathways, the ubiquitin-proteasome system and autophagy, were explored in DesKO and control muscle. Our results suggested an alteration of proteolysis pathways in DesKO muscle in response to mechanical overloading. Conclusion: Taken together, our results show that mechanical overloading increases the negative impact of the lack of desmin on myofibril organization and mitochondria. Furthermore, our results suggest that under these conditions, the repairing activity of autophagy is disturbed. Consequently, force generation is not improved despite muscle growth, suggesting that desmin is required for a complete response to resistance training in skeletal muscle.
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Affiliation(s)
- Pierre Joanne
- Sorbonne Université, Institut de Biologie Paris-Seine (IBPS), CNRS UMR 8256, Inserm ERL U1164, Biological Adaptation and Ageing, Paris, France
| | - Yeranuhi Hovhannisyan
- Sorbonne Université, Institut de Biologie Paris-Seine (IBPS), CNRS UMR 8256, Inserm ERL U1164, Biological Adaptation and Ageing, Paris, France
| | - Maximilien Bencze
- U955-IMRB, Team 10, Biology of the Neuromuscular System, Inserm, UPEC, ENVA, EFS, Créteil, France
| | - Marie-Thérèse Daher
- Sorbonne Université, Institut de Biologie Paris-Seine (IBPS), CNRS UMR 8256, Inserm ERL U1164, Biological Adaptation and Ageing, Paris, France
| | - Ara Parlakian
- Sorbonne Université, Institut de Biologie Paris-Seine (IBPS), CNRS UMR 8256, Inserm ERL U1164, Biological Adaptation and Ageing, Paris, France
| | - Geraldine Toutirais
- Muséum National d'Histoire Naturelle (MNHN), Unité Molécules de Communication et Adaptation des Micro-organismes (MCAM), CNRS UMR 7245, Plateau technique de Microscopie Electronique (PtME), Paris, France
| | - Jacqueline Gao-Li
- Sorbonne Université, Institut de Biologie Paris-Seine (IBPS), CNRS UMR 8256, Inserm ERL U1164, Biological Adaptation and Ageing, Paris, France
| | - Alain Lilienbaum
- Unité de Biologie Fonctionnelle et Adaptative, CNRS UMR 8251, Université de Paris, Paris, France
| | - Zhenlin Li
- Sorbonne Université, Institut de Biologie Paris-Seine (IBPS), CNRS UMR 8256, Inserm ERL U1164, Biological Adaptation and Ageing, Paris, France
| | - Ekaterini Kordeli
- Sorbonne Université, Institut de Biologie Paris-Seine (IBPS), CNRS UMR 8256, Inserm ERL U1164, Biological Adaptation and Ageing, Paris, France
| | - Arnaud Ferry
- Institut de Myologie, INSERM U974, Centre de Recherche en Myologie, Sorbonne Université, Paris, France.,Université de Paris, Paris, France
| | - Onnik Agbulut
- Sorbonne Université, Institut de Biologie Paris-Seine (IBPS), CNRS UMR 8256, Inserm ERL U1164, Biological Adaptation and Ageing, Paris, France
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16
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Gouvêa AL, Gracindo Silva M, Cabral B, Martinez CG, Lauthartte LC, Rodrigues Bastos W, Kurtenbach E. Progressive resistance exercise prevents muscle strength loss due to muscle atrophy induced by methylmercury systemic intoxication. JCSM CLINICAL REPORTS 2021. [DOI: 10.1002/crt2.34] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Affiliation(s)
- André Luiz Gouvêa
- Instituto de Biofísica Carlos Chagas Filho Universidade Federal do Rio de Janeiro Rio de Janeiro Rio de Janeiro 21941‐902 Brazil
- Instituto de Bioquímica Médica Leopoldo de Meis Universidade Federal do Rio de Janeiro Rio de Janeiro Rio de Janeiro 21941‐902 Brazil
| | - Marcia Gracindo Silva
- Instituto de Biofísica Carlos Chagas Filho Universidade Federal do Rio de Janeiro Rio de Janeiro Rio de Janeiro 21941‐902 Brazil
- Instituto de Bioquímica Médica Leopoldo de Meis Universidade Federal do Rio de Janeiro Rio de Janeiro Rio de Janeiro 21941‐902 Brazil
| | - Bruno Cabral
- Instituto de Biofísica Carlos Chagas Filho Universidade Federal do Rio de Janeiro Rio de Janeiro Rio de Janeiro 21941‐902 Brazil
| | - Camila Guerra Martinez
- Instituto de Biofísica Carlos Chagas Filho Universidade Federal do Rio de Janeiro Rio de Janeiro Rio de Janeiro 21941‐902 Brazil
| | | | - Waderley Rodrigues Bastos
- Laboratório de Biogeoquímica Ambiental Universidade Federal de Rondônia Porto Velho Rondônia 76801‐974 Brazil
| | - Eleonora Kurtenbach
- Instituto de Biofísica Carlos Chagas Filho Universidade Federal do Rio de Janeiro Rio de Janeiro Rio de Janeiro 21941‐902 Brazil
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17
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Baehr LM, Hughes DC, Lynch SA, Van Haver D, Maia TM, Marshall AG, Radoshevich L, Impens F, Waddell DS, Bodine SC. Identification of the MuRF1 Skeletal Muscle Ubiquitylome Through Quantitative Proteomics. FUNCTION (OXFORD, ENGLAND) 2021; 2:zqab029. [PMID: 34179788 PMCID: PMC8218097 DOI: 10.1093/function/zqab029] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 05/12/2021] [Accepted: 05/17/2021] [Indexed: 02/07/2023]
Abstract
MuRF1 (TRIM63) is a muscle-specific E3 ubiquitin ligase and component of the ubiquitin proteasome system. MuRF1 is transcriptionally upregulated under conditions that cause muscle loss, in both rodents and humans, and is a recognized marker of muscle atrophy. In this study, we used in vivo electroporation to determine whether MuRF1 overexpression alone can cause muscle atrophy and, in combination with ubiquitin proteomics, identify the endogenous MuRF1 substrates in skeletal muscle. Overexpression of MuRF1 in adult mice increases ubiquitination of myofibrillar and sarcoplasmic proteins, increases expression of genes associated with neuromuscular junction instability, and causes muscle atrophy. A total of 169 ubiquitination sites on 56 proteins were found to be regulated by MuRF1. MuRF1-mediated ubiquitination targeted both thick and thin filament contractile proteins, as well as, glycolytic enzymes, deubiquitinases, p62, and VCP. These data reveal a potential role for MuRF1 in not only the breakdown of the sarcomere but also the regulation of metabolism and other proteolytic pathways in skeletal muscle.
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Affiliation(s)
| | | | - Sarah A Lynch
- Department of Biology, University of North Florida, 1 UNF Drive, Jacksonville, FL 32224, USA
| | - Delphi Van Haver
- Department of Biomolecular Medicine, Ghent University, Ghent, Belgium,VIB Center for Medical Biotechnology, Ghent, Belgium,VIB Proteomics Core, Ghent, Belgium
| | - Teresa Mendes Maia
- Department of Biomolecular Medicine, Ghent University, Ghent, Belgium,VIB Center for Medical Biotechnology, Ghent, Belgium,VIB Proteomics Core, Ghent, Belgium
| | - Andrea G Marshall
- Department of Internal Medicine, Division of Endocrinology and Metabolism, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
| | - Lilliana Radoshevich
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
| | - Francis Impens
- Department of Biomolecular Medicine, Ghent University, Ghent, Belgium,VIB Center for Medical Biotechnology, Ghent, Belgium,VIB Proteomics Core, Ghent, Belgium
| | - David S Waddell
- Department of Biology, University of North Florida, 1 UNF Drive, Jacksonville, FL 32224, USA
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18
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Wallace MA, Aguirre NW, Marcotte GR, Marshall AG, Baehr LM, Hughes DC, Hamilton KL, Roberts MN, Lopez‐Dominguez JA, Miller BF, Ramsey JJ, Baar K. The ketogenic diet preserves skeletal muscle with aging in mice. Aging Cell 2021; 20:e13322. [PMID: 33675103 PMCID: PMC8045940 DOI: 10.1111/acel.13322] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 01/11/2021] [Accepted: 01/23/2021] [Indexed: 12/20/2022] Open
Abstract
The causes of the decline in skeletal muscle mass and function with age, known as sarcopenia, are poorly understood. Nutrition (calorie restriction) interventions impact many cellular processes and increase lifespan and preserve muscle mass and function with age. As we previously observed an increase in life span and muscle function in aging mice on a ketogenic diet (KD), we aimed to investigate the effect of a KD on the maintenance of skeletal muscle mass with age and the potential molecular mechanisms of this action. Twelve‐month‐old mice were assigned to an isocaloric control or KD until 16 or 26 months of age, at which time skeletal muscle was collected for evaluating mass, morphology, and biochemical properties. Skeletal muscle mass was significantly greater at 26 months in the gastrocnemius of mice on the KD. This result in KD mice was associated with a shift in fiber type from type IIb to IIa fibers and a range of molecular parameters including increased markers of NMJ remodeling, mitochondrial biogenesis, oxidative metabolism, and antioxidant capacity, while decreasing endoplasmic reticulum (ER) stress, protein synthesis, and proteasome activity. Overall, this study shows the effectiveness of a long‐term KD in mitigating sarcopenia. The diet preferentially preserved oxidative muscle fibers and improved mitochondrial and antioxidant capacity. These adaptations may result in a healthier cellular environment, decreasing oxidative and ER stress resulting in less protein turnover. These shifts allow mice to better maintain muscle mass and function with age.
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Affiliation(s)
- Marita A. Wallace
- Department of Neurobiology, Physiology and Behavior University of California Davis CA USA
- CellMet Performance Health Perth WA Australia
| | - Nicholas W. Aguirre
- Department of Neurobiology, Physiology and Behavior University of California Davis CA USA
| | - George R. Marcotte
- Department of Neurobiology, Physiology and Behavior University of California Davis CA USA
| | - Andrea G. Marshall
- Department of Neurobiology, Physiology and Behavior University of California Davis CA USA
| | - Leslie M. Baehr
- Department of Neurobiology, Physiology and Behavior University of California Davis CA USA
| | - David C. Hughes
- Department of Neurobiology, Physiology and Behavior University of California Davis CA USA
| | - Karyn L. Hamilton
- Department of Health and Exercise Science Colorado State University Fort Collins CO USA
| | - Megan N. Roberts
- Department of Molecular Biosciences School of Veterinary Medicine University of California Davis CA USA
| | | | - Benjamin F. Miller
- Aging and Metabolism Research Program Oklahoma Medical Research Foundation Oklahoma City OK USA
| | - Jon J. Ramsey
- Department of Molecular Biosciences School of Veterinary Medicine University of California Davis CA USA
| | - Keith Baar
- Department of Neurobiology, Physiology and Behavior University of California Davis CA USA
- Department of Physiology and Membrane Biology School of Medicine University of California Davis CA USA
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19
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Zanella BTT, Magiore IC, Duran BOS, Pereira GG, Vicente IST, Carvalho PLPF, Salomão RAS, Mareco EA, Carvalho RF, de Paula TG, Barros MM, Dal-Pai-Silva M. Ascorbic Acid Supplementation Improves Skeletal Muscle Growth in Pacu ( Piaractus mesopotamicus) Juveniles: In Vivo and In Vitro Studies. Int J Mol Sci 2021; 22:2995. [PMID: 33804272 PMCID: PMC7998472 DOI: 10.3390/ijms22062995] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 03/11/2021] [Accepted: 03/12/2021] [Indexed: 02/06/2023] Open
Abstract
In fish, fasting leads to loss of muscle mass. This condition triggers oxidative stress, and therefore, antioxidants can be an alternative to muscle recovery. We investigated the effects of antioxidant ascorbic acid (AA) on the morphology, antioxidant enzyme activity, and gene expression in the skeletal muscle of pacu (Piaractus mesopotamicus) following fasting, using in vitro and in vivo strategies. Isolated muscle cells of the pacu were subjected to 72 h of nutrient restriction, followed by 24 h of incubation with nutrients or nutrients and AA (200 µM). Fish were fasted for 15 days, followed by 6 h and 15 and 30 days of refeeding with 100, 200, and 400 mg/kg of AA supplementation. AA addition increased cell diameter and the expression of anabolic and cell proliferation genes in vitro. In vivo, 400 mg/kg of AA increased anabolic and proliferative genes expression at 6 h of refeeding, the fiber diameter and the expression of genes related to cell proliferation at 15 days, and the expression of catabolic and oxidative metabolism genes at 30 days. Catalase activity remained low in the higher supplementation group. In conclusion, AA directly affected the isolated muscle cells, and the higher AA supplementation positively influenced muscle growth after fasting.
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Affiliation(s)
- Bruna Tereza Thomazini Zanella
- Department of Structural and Functional Biology, Institute of Biosciences, São Paulo State University, UNESP, Botucatu 18618-689, São Paulo, Brazil; (B.T.T.Z.); (I.C.M.); (G.G.P.); (R.F.C.); (T.G.d.P.)
| | - Isabele Cristina Magiore
- Department of Structural and Functional Biology, Institute of Biosciences, São Paulo State University, UNESP, Botucatu 18618-689, São Paulo, Brazil; (B.T.T.Z.); (I.C.M.); (G.G.P.); (R.F.C.); (T.G.d.P.)
| | - Bruno Oliveira Silva Duran
- Department of Histology, Embryology and Cell Biology, Institute of Biological Sciences, Federal University of Goiás (UFG), Goiânia 74690-900, Goiás, Brazil;
| | - Guilherme Gutierrez Pereira
- Department of Structural and Functional Biology, Institute of Biosciences, São Paulo State University, UNESP, Botucatu 18618-689, São Paulo, Brazil; (B.T.T.Z.); (I.C.M.); (G.G.P.); (R.F.C.); (T.G.d.P.)
| | - Igor Simões Tiagua Vicente
- Department of Breeding and Animal Nutrition, School of Veterinary Medicine and Animal Science, São Paulo State University, UNESP, Botucatu 18618-681, São Paulo, Brazil; (I.S.T.V.); (P.L.P.F.C.); (M.M.B.)
| | - Pedro Luiz Pucci Figueiredo Carvalho
- Department of Breeding and Animal Nutrition, School of Veterinary Medicine and Animal Science, São Paulo State University, UNESP, Botucatu 18618-681, São Paulo, Brazil; (I.S.T.V.); (P.L.P.F.C.); (M.M.B.)
| | - Rondinelle Artur Simões Salomão
- Environment and Regional Development Graduate Program, University of Western São Paulo, Presidente Prudente 19050-680, São Paulo, Brazil; (R.A.S.S.); (E.A.M.)
| | - Edson Assunção Mareco
- Environment and Regional Development Graduate Program, University of Western São Paulo, Presidente Prudente 19050-680, São Paulo, Brazil; (R.A.S.S.); (E.A.M.)
| | - Robson Francisco Carvalho
- Department of Structural and Functional Biology, Institute of Biosciences, São Paulo State University, UNESP, Botucatu 18618-689, São Paulo, Brazil; (B.T.T.Z.); (I.C.M.); (G.G.P.); (R.F.C.); (T.G.d.P.)
| | - Tassiana Gutierrez de Paula
- Department of Structural and Functional Biology, Institute of Biosciences, São Paulo State University, UNESP, Botucatu 18618-689, São Paulo, Brazil; (B.T.T.Z.); (I.C.M.); (G.G.P.); (R.F.C.); (T.G.d.P.)
| | - Margarida Maria Barros
- Department of Breeding and Animal Nutrition, School of Veterinary Medicine and Animal Science, São Paulo State University, UNESP, Botucatu 18618-681, São Paulo, Brazil; (I.S.T.V.); (P.L.P.F.C.); (M.M.B.)
| | - Maeli Dal-Pai-Silva
- Department of Structural and Functional Biology, Institute of Biosciences, São Paulo State University, UNESP, Botucatu 18618-689, São Paulo, Brazil; (B.T.T.Z.); (I.C.M.); (G.G.P.); (R.F.C.); (T.G.d.P.)
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20
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Lawrence MM, Van Pelt DW, Confides AL, Hettinger ZR, Hunt ER, Reid JJ, Laurin JL, Peelor FF, Butterfield TA, Miller BF, Dupont-Versteegden EE. Muscle from aged rats is resistant to mechanotherapy during atrophy and reloading. GeroScience 2021; 43:65-83. [PMID: 32588343 PMCID: PMC8050124 DOI: 10.1007/s11357-020-00215-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Accepted: 06/09/2020] [Indexed: 12/22/2022] Open
Abstract
Massage is a viable mechanotherapy to improve protein turnover during disuse atrophy and improve muscle regrowth during recovery from disuse atrophy in adult muscle. Therefore, we investigated whether massage can cause beneficial adaptations in skeletal muscle from aged rats during normal weight-bearing (WB) conditions, hindlimb suspension (HS), or reloading (RE) following HS. Aged (30 months) male Fischer 344/Brown Norway rats were divided into two experiments: (1) WB for 7 days (WB, n = 8), WB with massage (WBM, n = 8), HS for 7 days (HS7, n = 8), or HS with massage (HSM, n = 8), and (2) WB for 14 days (WB14, n = 8), HS for 14 days (HS14, n = 8), reloading (RE, n = 10), or reloading with massage (REM, n = 10) for 7 days following HS. Deuterium oxide (D2O) labeling was used to assess dynamic protein and ribosome turnover in each group and anabolic signaling pathways were assessed. Massage did have an anabolic benefit during RE or WB. In contrast, massage during HS enhanced myofibrillar protein turnover in both the massaged limb and contralateral non-massaged limb compared with HS, but this did not prevent muscle loss. Overall, the data demonstrate that massage is not an effective mechanotherapy for prevention of atrophy during muscle disuse or recovery of muscle mass during reloading in aged rats.
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Affiliation(s)
- Marcus M Lawrence
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, 73104, USA
| | - Douglas W Van Pelt
- Department of Physical Therapy, University of Kentucky, Lexington, KY, 40536, USA
- Center for Muscle Biology, University of Kentucky, Lexington, KY, 40536, USA
| | - Amy L Confides
- Department of Physical Therapy, University of Kentucky, Lexington, KY, 40536, USA
- Center for Muscle Biology, University of Kentucky, Lexington, KY, 40536, USA
| | - Zachary R Hettinger
- Department of Physical Therapy, University of Kentucky, Lexington, KY, 40536, USA
- Center for Muscle Biology, University of Kentucky, Lexington, KY, 40536, USA
| | - Emily R Hunt
- Department of Physical Therapy, University of Kentucky, Lexington, KY, 40536, USA
- Center for Muscle Biology, University of Kentucky, Lexington, KY, 40536, USA
| | - Justin J Reid
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, 73104, USA
| | - Jaime L Laurin
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, 73104, USA
| | - Frederick F Peelor
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, 73104, USA
| | - Timothy A Butterfield
- Center for Muscle Biology, University of Kentucky, Lexington, KY, 40536, USA
- Department of Athletic Training and Clinical Nutrition, University of Kentucky, Lexington, KY, 40536, USA
| | - Benjamin F Miller
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, 73104, USA
| | - Esther E Dupont-Versteegden
- Department of Physical Therapy, University of Kentucky, Lexington, KY, 40536, USA.
- Center for Muscle Biology, University of Kentucky, Lexington, KY, 40536, USA.
- College of Health Sciences, University of Kentucky, 900 S. Limestone CTW210E, Lexington, KY, 40536-0200, USA.
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21
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Bass JJ, Nakhuda A, Deane CS, Brook MS, Wilkinson DJ, Phillips BE, Philp A, Tarum J, Kadi F, Andersen D, Garcia AM, Smith K, Gallagher IJ, Szewczyk NJ, Cleasby ME, Atherton PJ. Overexpression of the vitamin D receptor (VDR) induces skeletal muscle hypertrophy. Mol Metab 2020; 42:101059. [PMID: 32771696 PMCID: PMC7475200 DOI: 10.1016/j.molmet.2020.101059] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Revised: 07/23/2020] [Accepted: 07/28/2020] [Indexed: 12/30/2022] Open
Abstract
OBJECTIVE The Vitamin D receptor (VDR) has been positively associated with skeletal muscle mass, function and regeneration. Mechanistic studies have focused on the loss of the receptor, with in vivo whole-body knockout models demonstrating reduced myofibre size and function and impaired muscle development. To understand the mechanistic role upregulation of the VDR elicits in muscle mass/health, we studied the impact of VDR over-expression (OE) in vivo before exploring the importance of VDR expression upon muscle hypertrophy in humans. METHODS Wistar rats underwent in vivo electrotransfer (IVE) to overexpress the VDR in the Tibialis anterior (TA) muscle for 10 days, before comprehensive physiological and metabolic profiling to characterise the influence of VDR-OE on muscle protein synthesis (MPS), anabolic signalling and satellite cell activity. Stable isotope tracer (D2O) techniques were used to assess sub-fraction protein synthesis, alongside RNA-Seq analysis. Finally, human participants underwent 20 wks of resistance exercise training, with body composition and transcriptomic analysis. RESULTS Muscle VDR-OE yielded total protein and RNA accretion, manifesting in increased myofibre area, i.e., hypertrophy. The observed increases in MPS were associated with enhanced anabolic signalling, reflecting translational efficiency (e.g., mammalian target of rapamycin (mTOR-signalling), with no effects upon protein breakdown markers being observed. Additionally, RNA-Seq illustrated marked extracellular matrix (ECM) remodelling, while satellite cell content, markers of proliferation and associated cell-cycled related gene-sets were upregulated. Finally, induction of VDR mRNA correlated with muscle hypertrophy in humans following long-term resistance exercise type training. CONCLUSION VDR-OE stimulates muscle hypertrophy ostensibly via heightened protein synthesis, translational efficiency, ribosomal expansion and upregulation of ECM remodelling-related gene-sets. Furthermore, VDR expression is a robust marker of the hypertrophic response to resistance exercise in humans. The VDR is a viable target of muscle maintenance through testable Vitamin D molecules, as active molecules and analogues.
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Affiliation(s)
- Joseph J Bass
- MRC/ARUK Centre for Musculoskeletal Ageing Research and National Institute for Health Research (NIHR), Nottingham Biomedical Research Centre (BRC), School of Medicine, University of Nottingham, DE22 3DT, UK
| | - Asif Nakhuda
- MRC/ARUK Centre for Musculoskeletal Ageing Research and National Institute for Health Research (NIHR), Nottingham Biomedical Research Centre (BRC), School of Medicine, University of Nottingham, DE22 3DT, UK
| | - Colleen S Deane
- Department of Sport and Health Sciences, University of Exeter, EX1 2LU, UK
| | - Matthew S Brook
- MRC/ARUK Centre for Musculoskeletal Ageing Research and National Institute for Health Research (NIHR), Nottingham Biomedical Research Centre (BRC), School of Medicine, University of Nottingham, DE22 3DT, UK
| | - Daniel J Wilkinson
- MRC/ARUK Centre for Musculoskeletal Ageing Research and National Institute for Health Research (NIHR), Nottingham Biomedical Research Centre (BRC), School of Medicine, University of Nottingham, DE22 3DT, UK
| | - Bethan E Phillips
- MRC/ARUK Centre for Musculoskeletal Ageing Research and National Institute for Health Research (NIHR), Nottingham Biomedical Research Centre (BRC), School of Medicine, University of Nottingham, DE22 3DT, UK
| | - Andrew Philp
- Mitochondrial Metabolism and Ageing Laboratory, Diabetes and Metabolism Division, Garvan Institute of Medical Research, NSW, 2010, Australia; School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, B15 2TT, UK
| | - Janelle Tarum
- School of Health Sciences, Örebro University, 70182, Sweden
| | - Fawzi Kadi
- School of Health Sciences, Örebro University, 70182, Sweden
| | - Ditte Andersen
- Molecular Physiology of Diabetes Laboratory, Dept. of Comparative Biomedical Sciences, Royal Veterinary College, NW1 0TU, UK
| | - Amadeo Muñoz Garcia
- Institute of Metabolism and Systems Research, The University of Birmingham, Birmingham, UK; Department of Bioinformatics - BiGCaT, NUTRIM School of Nutrition and Metabolism in Translational Research, Maastricht University, Maastricht, the Netherlands
| | - Ken Smith
- MRC/ARUK Centre for Musculoskeletal Ageing Research and National Institute for Health Research (NIHR), Nottingham Biomedical Research Centre (BRC), School of Medicine, University of Nottingham, DE22 3DT, UK
| | - Iain J Gallagher
- Physiology, Exercise and Nutrition Research Group, Faculty of Health Sciences and Sport, University of Stirling, FK9 4LA, UK
| | - Nathaniel J Szewczyk
- MRC/ARUK Centre for Musculoskeletal Ageing Research and National Institute for Health Research (NIHR), Nottingham Biomedical Research Centre (BRC), School of Medicine, University of Nottingham, DE22 3DT, UK
| | - Mark E Cleasby
- Molecular Physiology of Diabetes Laboratory, Dept. of Comparative Biomedical Sciences, Royal Veterinary College, NW1 0TU, UK
| | - Philip J Atherton
- MRC/ARUK Centre for Musculoskeletal Ageing Research and National Institute for Health Research (NIHR), Nottingham Biomedical Research Centre (BRC), School of Medicine, University of Nottingham, DE22 3DT, UK.
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22
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Nakai N, Kitai S, Iida N, Inoue S, Higashida K. Autophagy under glucose starvation enhances protein translation initiation in response to re-addition of glucose in C2C12 myotubes. FEBS Open Bio 2020; 10:2149-2156. [PMID: 32882752 PMCID: PMC7530399 DOI: 10.1002/2211-5463.12970] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 08/21/2020] [Accepted: 08/25/2020] [Indexed: 01/02/2023] Open
Abstract
Proteolysis is known to play a crucial role in maintaining skeletal muscle mass and function. Autophagy is a conserved intracellular process for the bulk degradation of proteins in lysosomes. Although nutrient starvation is known to induce autophagy, the effect of nutrient repletion following starvation on the mTOR pathway‐mediated protein translation remains unclear. In the present study, we examined the effect of glucose starvation on the initiation of protein translation in response to glucose re‐addition in C2C12 myotubes. Glucose starvation decreased the phosphorylation of p70 S6 kinase (p70S6K), a bonafide marker for protein translation initiation. Following re‐addition of glucose, phosphorylation of p70S6K markedly increased only in glucose‐starved cells. Inhibiting autophagy using pharmacological inhibitors diminished the effect of glucose re‐addition on the phosphorylation of p70S6K, whereas inhibition of the ubiquitin‐proteasome system did not exert any effect. In conclusion, autophagy under glucose starvation partially accounts for the activation of translation initiation by re‐addition of glucose.
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Affiliation(s)
- Naoya Nakai
- Laboratory of Exercise Nutrition, Department of Nutrition, University of Shiga Prefecture, Hikone, Japan
| | - Saki Kitai
- Laboratory of Exercise Nutrition, Department of Nutrition, University of Shiga Prefecture, Hikone, Japan
| | - Noriko Iida
- Laboratory of Exercise Nutrition, Department of Nutrition, University of Shiga Prefecture, Hikone, Japan
| | - Sachika Inoue
- Laboratory of Exercise Nutrition, Department of Nutrition, University of Shiga Prefecture, Hikone, Japan
| | - Kazuhiko Higashida
- Laboratory of Exercise Nutrition, Department of Nutrition, University of Shiga Prefecture, Hikone, Japan
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23
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Bodine SC. Edward F. Adolph Distinguished Lecture. Skeletal muscle atrophy: Multiple pathways leading to a common outcome. J Appl Physiol (1985) 2020; 129:272-282. [PMID: 32644910 DOI: 10.1152/japplphysiol.00381.2020] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Skeletal muscle atrophy continues to be a serious consequence of many diseases and conditions for which there is no treatment. Our understanding of the mechanisms regulating skeletal muscle mass has improved considerably over the past two decades. For many years it was known that skeletal muscle atrophy resulted from an imbalance between protein synthesis and protein breakdown, with the net balance shifting toward protein breakdown. However, the molecular and cellular mechanisms underlying the increased breakdown of myofibrils was unknown. Over the past two decades, numerous reports have identified novel genes and signaling pathways that are upregulated and activated in response to stimuli such as disuse, inflammation, metabolic stress, starvation and others that induce muscle atrophy. This review summarizes the discovery efforts performed in the identification of several pathways involved in the regulation of skeletal muscle mass: the mammalian target of rapamycin (mTORC1) and the ubiquitin proteasome pathway and the E3 ligases, MuRF1 and MAFbx. While muscle atrophy is a common outcome of many diseases, it is doubtful that a single gene or pathway initiates or mediates the breakdown of myofibrils. Interestingly, however, is the observation that upregulation of the E3 ligases, MuRF1 and MAFbx, is a common feature of many divergent atrophy conditions. The challenge for the field of muscle biology is to understand how all of the various molecules, transcription factors, and signaling pathways interact to produce muscle atrophy and to identify the critical factors for intervention.
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Affiliation(s)
- Sue C Bodine
- Department of Internal Medicine/Endocrinology and Metabolism, University of Iowa Carver College of Medicine, Iowa City, Iowa
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24
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Tan KT, Ang STJ, Tsai SY. Sarcopenia: Tilting the Balance of Protein Homeostasis. Proteomics 2019; 20:e1800411. [PMID: 31722440 DOI: 10.1002/pmic.201800411] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Revised: 11/04/2019] [Indexed: 12/14/2022]
Abstract
Sarcopenia, defined as age-associated decline of muscle mass and function, is a risk factor for mortality and disability, and comorbid with several chronic diseases such as type II diabetes and cardiovascular diseases. Clinical trials showed that nutritional supplements had positive effects on muscle mass, but not on muscle function and strength, demonstrating our limited understanding of the molecular events involved in the ageing muscle. Protein homeostasis, the equilibrium between protein synthesis and degradation, is proposed as the major mechanism underlying the development of sarcopenia. As the key central regulator of protein homeostasis, the mammalian target of rapamycin (mTOR) is proposed to be essential for muscle hypertrophy. Paradoxically, sustained activation of mTOR complex 1 (mTORC1) is associated with a loss of sensitivity to extracellular signaling in the elderly. It is not understood why sustained mTORC1 activity, which should induce muscle hypertrophy, instead results in muscle atrophy. Here, recent findings on the implications of disrupting protein homeostasis on muscle physiology and sarcopenia development in the context of mTOR/protein kinase B (AKT) signaling are reviewed. Understanding the role of these molecular mechanisms during the ageing process will contribute towards the development of targeted therapies that will improve protein metabolism and reduce sarcopenia.
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Affiliation(s)
- Kuan Ting Tan
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, 2 Medical Drive, MD9 Admin Office, Singapore, 117597, Singapore
| | - Seok-Ting Jamie Ang
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, 2 Medical Drive, MD9 Admin Office, Singapore, 117597, Singapore
| | - Shih-Yin Tsai
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, 2 Medical Drive, MD9 Admin Office, Singapore, 117597, Singapore
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25
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Van Pelt DW, Confides AL, Abshire SM, Hunt ER, Dupont-Versteegden EE, Butterfield TA. Age-related responses to a bout of mechanotherapy in skeletal muscle of rats. J Appl Physiol (1985) 2019; 127:1782-1791. [PMID: 31670600 PMCID: PMC6962605 DOI: 10.1152/japplphysiol.00641.2019] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Revised: 10/14/2019] [Accepted: 10/24/2019] [Indexed: 12/25/2022] Open
Abstract
Cyclic compressive loading (CCL) is a massage mimetic that improves muscle regrowth from atrophy in adult rats. Therefore, we tested if a single bout of CCL increases anabolic signaling and protein synthesis in muscle during normal, weight-bearing conditions in gastrocnemius muscle from adult and aged rats. Male Brown Norway/F344 rats at 10 (adult) and 30 (aged) months of age were assigned control or CCL (receiving a single bout of CCL). Twenty-four hours following a single bout of CCL there was no change in protein synthesis, Akt, or GSK3β signaling at either age, despite adult rats having higher abundance and activation of mechanosensitive pathways (integrins and integrin-linked kinase). Murf1 was elevated in response to CCL in both age groups, potentially indicating muscle remodeling. Muscle from aged rats exhibited an increase in heat shock protein (HSP) 25 and HSP70 and in the cold shock protein RNA-binding motif 3 (RBM3), demonstrating a unique stress response to CCL in aged muscle only. Finally, muscle from aged rats exhibited higher basal protein synthesis that was corroborated by elevated eIF2Bε and rpS6 signaling, without an additional effect of CCL. In summary, a single bout of CCL does not have anabolic effects on skeletal muscle during normal, weight-bearing conditions, even though it has previously been shown to improve regrowth from atrophy. These data demonstrate that interventions that may help recover from atrophy do not necessarily induce muscle hypertrophy in unperturbed conditions.NEW & NOTEWORTHY Massage has been demonstrated to be an effective mechanotherapy to improve recovery from atrophy in adult skeletal muscle; however, this study shows that a single bout of massage fails to increase protein synthesis or anabolic signaling in adult or aged skeletal muscle during normal, weight-bearing conditions. Altogether, our data suggest massage is a useful mechanotherapy for preserving skeletal muscle when combined with other interventions but is not an anabolic stimulus on its own.
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Affiliation(s)
- Douglas W Van Pelt
- Department of Physical Therapy, University of Kentucky, Lexington, Kentucky
- Center for Muscle Biology, University of Kentucky, Lexington, Kentucky
| | - Amy L Confides
- Department of Physical Therapy, University of Kentucky, Lexington, Kentucky
- Center for Muscle Biology, University of Kentucky, Lexington, Kentucky
| | - Sarah M Abshire
- Center for Muscle Biology, University of Kentucky, Lexington, Kentucky
- Department of Athletic Training and Clinical Nutrition, University of Kentucky, Lexington, Kentucky
| | - Emily R Hunt
- Center for Muscle Biology, University of Kentucky, Lexington, Kentucky
- Rehabilitation Sciences PhD Program, University of Kentucky, Lexington, Kentucky
| | - Esther E Dupont-Versteegden
- Department of Physical Therapy, University of Kentucky, Lexington, Kentucky
- Center for Muscle Biology, University of Kentucky, Lexington, Kentucky
| | - Timothy A Butterfield
- Center for Muscle Biology, University of Kentucky, Lexington, Kentucky
- Department of Athletic Training and Clinical Nutrition, University of Kentucky, Lexington, Kentucky
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26
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Figueiredo VC. Revisiting the roles of protein synthesis during skeletal muscle hypertrophy induced by exercise. Am J Physiol Regul Integr Comp Physiol 2019; 317:R709-R718. [PMID: 31508978 DOI: 10.1152/ajpregu.00162.2019] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Protein synthesis is deemed the underpinning mechanism enhancing protein balance required for skeletal muscle hypertrophy in response to resistance exercise. The current model of skeletal muscle hypertrophy induced by resistance training states that the acute increase in the rates of protein synthesis after each bout of resistance exercise is the basis for muscle growth. Within this paradigm, each resistance exercise session would add a specific amount of muscle mass; therefore, muscle hypertrophy could be defined as the result of intermittent and short-lived increases in muscle protein synthesis rates following each resistance exercise session. Although a substantial amount of data has accumulated in the last decades regarding the acute changes in protein synthesis (or translational efficiency) following resistance exercise, considerable gaps on the mechanism of muscle growth still exist. Ribosome biogenesis and translational capacity have emerged as important mediators of skeletal muscle hypertrophy. Recent advances in the field have demonstrated that skeletal muscle hypertrophy is associated with markers of translational capacity and long-term changes in protein synthesis under resting conditions. This review will discuss the caveats of the current model of skeletal muscle hypertrophy induced by resistance training while proposing a working model that takes into consideration the novel data generated by independent laboratories utilizing different methodologies. It is argued, herein, that the role of protein synthesis in the current model of muscle hypertrophy warrants revisiting.
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Affiliation(s)
- Vandré Casagrande Figueiredo
- College of Health Sciences, Department of Rehabilitation Sciences, the Center for Muscle Biology, University of Kentucky, Lexington, Kentucky
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27
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Ato S, Kido K, Sato K, Fujita S. Type 2 diabetes causes skeletal muscle atrophy but does not impair resistance training-mediated myonuclear accretion and muscle mass gain in rats. Exp Physiol 2019; 104:1518-1531. [PMID: 31328833 PMCID: PMC6790689 DOI: 10.1113/ep087585] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2019] [Accepted: 07/19/2019] [Indexed: 12/12/2022]
Abstract
New Findings What is the central question of this study? Type 2 diabetes mellitus (T2DM) causes skeletal muscle atrophy; does it affect resistance training (RT)‐mediated molecular adaptations and subsequent muscle hypertrophy? What is the main finding and its importance? Although skeletal muscle mass and regulation were not preserved under conditions of T2DM, the response of RT‐induced skeletal muscle hypertrophy was not impaired in T2DM rat skeletal muscle. These findings suggest that the capacity of RT‐mediated muscle mass gain is not diminished in the T2DM condition.
Abstract Type 2 diabetes mellitus (T2DM) is known to cause skeletal muscle atrophy. However, it is not known whether T2DM affects resistance training (RT)‐mediated molecular adaptations and subsequent muscle hypertrophy. Therefore, we investigated the effect of T2DM on response of skeletal muscle hypertrophy to chronic RT using a rat resistance exercise mimetic model. T2DM and healthy control rats were subjected to 18 bouts (3 times per week) of chronic RT on unilateral lower legs. RT significantly increased gastrocnemius muscle mass and myonuclei in both T2DM and healthy control rats to the same extent, even though T2DM caused muscle atrophy in the resting condition. Further, T2DM significantly reduced mechanistic target of rapamycin complex 1 (mTORC1) activity (phosphorylation of p70S6KThr389 and 4E‐BP1Thr37/46) to insulin stimulation and the number of myonuclei in the untrained basal condition, but RT‐mediated adaptations were not affected by T2DM. These findings suggested that although the skeletal muscle mass and regulation were not preserved under basal conditions of T2DM, the response of RT‐induced skeletal muscle hypertrophy was not impaired in T2DM rat skeletal muscle.
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Affiliation(s)
- Satoru Ato
- Graduate School of Sport and Health Science, Ritsumeikan University, Kusatsu, Japan
| | - Kohei Kido
- Graduate School of Sport and Health Science, Ritsumeikan University, Kusatsu, Japan
| | - Koji Sato
- Faculty of Human Development, Kobe University, Kobe, Japan
| | - Satoshi Fujita
- Graduate School of Sport and Health Science, Ritsumeikan University, Kusatsu, Japan
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28
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Hunt LC, Stover J, Haugen B, Shaw TI, Li Y, Pagala VR, Finkelstein D, Barton ER, Fan Y, Labelle M, Peng J, Demontis F. A Key Role for the Ubiquitin Ligase UBR4 in Myofiber Hypertrophy in Drosophila and Mice. Cell Rep 2019; 28:1268-1281.e6. [PMID: 31365869 PMCID: PMC6697171 DOI: 10.1016/j.celrep.2019.06.094] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Revised: 05/07/2019] [Accepted: 06/26/2019] [Indexed: 12/31/2022] Open
Abstract
Skeletal muscle cell (myofiber) atrophy is a detrimental component of aging and cancer that primarily results from muscle protein degradation via the proteasome and ubiquitin ligases. Transcriptional upregulation of some ubiquitin ligases contributes to myofiber atrophy, but little is known about the role that most other ubiquitin ligases play in this process. To address this question, we have used RNAi screening in Drosophila to identify the function of > 320 evolutionarily conserved ubiquitin ligases in myofiber size regulation in vivo. We find that whereas RNAi for some ubiquitin ligases induces myofiber atrophy, loss of others (including the N-end rule ubiquitin ligase UBR4) promotes hypertrophy. In Drosophila and mouse myofibers, loss of UBR4 induces hypertrophy via decreased ubiquitination and degradation of a core set of target proteins, including the HAT1/RBBP4/RBBP7 histone-binding complex. Together, this study defines the repertoire of ubiquitin ligases that regulate myofiber size and the role of UBR4 in myofiber hypertrophy.
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Affiliation(s)
- Liam C Hunt
- Division of Developmental Biology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA; Department of Developmental Neurobiology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
| | - Jared Stover
- Division of Developmental Biology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA; Department of Developmental Neurobiology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
| | - Benard Haugen
- Division of Developmental Biology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA; Department of Developmental Neurobiology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
| | - Timothy I Shaw
- Department of Structural Biology, Center for Proteomics and Metabolomics, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
| | - Yuxin Li
- Department of Structural Biology, Center for Proteomics and Metabolomics, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
| | - Vishwajeeth R Pagala
- Department of Structural Biology, Center for Proteomics and Metabolomics, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
| | - David Finkelstein
- Department of Computational Biology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
| | - Elisabeth R Barton
- College of Health & Human Performance Applied Physiology & Kinesiology, University of Florida, 124 Florida Gym, 1864 Stadium Road, Gainesville, FL 32611, USA
| | - Yiping Fan
- Department of Computational Biology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
| | - Myriam Labelle
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA; Solid Tumor Program, Comprehensive Cancer Center, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
| | - Junmin Peng
- Department of Structural Biology, Center for Proteomics and Metabolomics, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA; Department of Developmental Neurobiology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
| | - Fabio Demontis
- Division of Developmental Biology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA; Department of Developmental Neurobiology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA.
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29
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Seaborne RA, Hughes DC, Turner DC, Owens DJ, Baehr LM, Gorski P, Semenova EA, Borisov OV, Larin AK, Popov DV, Generozov EV, Sutherland H, Ahmetov II, Jarvis JC, Bodine SC, Sharples AP. UBR5 is a novel E3 ubiquitin ligase involved in skeletal muscle hypertrophy and recovery from atrophy. J Physiol 2019; 597:3727-3749. [PMID: 31093990 DOI: 10.1113/jp278073] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Accepted: 05/10/2019] [Indexed: 01/03/2023] Open
Abstract
KEY POINTS We have recently identified that a HECT domain E3 ubiquitin ligase, named UBR5, is altered epigenetically (via DNA methylation) after human skeletal muscle hypertrophy, where its gene expression is positively correlated with increasing lean leg mass after training and retraining. In the present study we extensively investigate this novel and uncharacterised E3 ubiquitin ligase (UBR5) in skeletal muscle atrophy, recovery from atrophy and injury, anabolism and hypertrophy. We demonstrated that UBR5 was epigenetically altered via DNA methylation during recovery from atrophy. We also determined that UBR5 was alternatively regulated versus well characterised E3 ligases, MuRF1/MAFbx, at the gene expression level during atrophy, recovery from atrophy and hypertrophy. UBR5 also increased at the protein level during recovery from atrophy and injury, hypertrophy and during human muscle cell differentiation. Finally, in humans, genetic variations of the UBR5 gene were strongly associated with larger fast-twitch muscle fibres and strength/power performance versus endurance/untrained phenotypes. ABSTRACT We aimed to investigate a novel and uncharacterized E3 ubiquitin ligase in skeletal muscle atrophy, recovery from atrophy/injury, anabolism and hypertrophy. We demonstrated an alternate gene expression profile for UBR5 vs. well characterized E3-ligases, MuRF1/MAFbx, where, after atrophy evoked by continuous-low-frequency electrical-stimulation in rats, MuRF1/MAFbx were both elevated, yet UBR5 was unchanged. Furthermore, after recovery of muscle mass post TTX-induced atrophy in rats, UBR5 was hypomethylated and increased at the gene expression level, whereas a suppression of MuRF1/MAFbx was observed. At the protein level, we also demonstrated a significant increase in UBR5 after recovery of muscle mass from hindlimb unloading in both adult and aged rats, as well as after recovery from atrophy evoked by nerve crush injury in mice. During anabolism and hypertrophy, UBR5 gene expression increased following acute loading in three-dimensional bioengineered mouse muscle in vitro, and after chronic electrical stimulation-induced hypertrophy in rats in vivo, without increases in MuRF1/MAFbx. Additionally, UBR5 protein abundance increased following functional overload-induced hypertrophy of the plantaris muscle in mice and during differentiation of primary human muscle cells. Finally, in humans, genetic association studies (>700,000 single nucleotide polymorphisms) demonstrated that the A alleles of rs10505025 and rs4734621 single nucleotide polymorphisms in the UBR5 gene were strongly associated with larger cross-sectional area of fast-twitch muscle fibres and favoured strength/power vs. endurance/untrained phenotypes. Overall, we suggest that: (i) UBR5 comprises a novel E3 ubiquitin ligase that is inversely regulated to MuRF1/MAFbx; (ii) UBR5 is epigenetically regulated; and (iii) UBR5 is elevated at both the gene expression and protein level during recovery from skeletal muscle atrophy and hypertrophy.
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Affiliation(s)
- Robert A Seaborne
- Stem Cells, Ageing and Molecular Physiology Unit, Exercise Metabolism and Adaptation Research Group, Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, UK.,Institute for Science and Technology in Medicine (ISTM), School of Medicine, Keele University, Keele, UK.,Centre for Genomics and Child Health, Blizard Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - David C Hughes
- Department of Internal Medicine, Division of Endocrinology and Metabolism, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Daniel C Turner
- Stem Cells, Ageing and Molecular Physiology Unit, Exercise Metabolism and Adaptation Research Group, Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, UK.,Institute for Science and Technology in Medicine (ISTM), School of Medicine, Keele University, Keele, UK
| | - Daniel J Owens
- Stem Cells, Ageing and Molecular Physiology Unit, Exercise Metabolism and Adaptation Research Group, Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, UK
| | - Leslie M Baehr
- Department of Internal Medicine, Division of Endocrinology and Metabolism, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Piotr Gorski
- Stem Cells, Ageing and Molecular Physiology Unit, Exercise Metabolism and Adaptation Research Group, Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, UK.,Institute for Science and Technology in Medicine (ISTM), School of Medicine, Keele University, Keele, UK
| | - Ekaterina A Semenova
- Department of Molecular Biology and Genetics, Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, Moscow, Russia
| | - Oleg V Borisov
- Department of Molecular Biology and Genetics, Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, Moscow, Russia.,Institute for Genomic Statistics and Bioinformatics, University Hospital Bonn, Bonn, Germany
| | - Andrey K Larin
- Department of Molecular Biology and Genetics, Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, Moscow, Russia
| | - Daniil V Popov
- Laboratory of Exercise Physiology, Institute of Biomedical Problems of the Russian Academy of Sciences, Moscow, Russia
| | - Edward V Generozov
- Department of Molecular Biology and Genetics, Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, Moscow, Russia
| | - Hazel Sutherland
- Exercise Metabolism and Adaptation Research Group, Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, UK
| | - Ildus I Ahmetov
- Department of Molecular Biology and Genetics, Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, Moscow, Russia.,Laboratory of Molecular Genetics, Kazan State Medical University, Kazan, Russia.,Department of Physical Education, Plekhanov Russian University of Economics, Moscow, Russia.,Exercise Metabolism and Adaptation Research Group, Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, UK
| | - Jonathan C Jarvis
- Exercise Metabolism and Adaptation Research Group, Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, UK
| | - Sue C Bodine
- Department of Internal Medicine, Division of Endocrinology and Metabolism, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Adam P Sharples
- Stem Cells, Ageing and Molecular Physiology Unit, Exercise Metabolism and Adaptation Research Group, Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, UK.,Institute for Science and Technology in Medicine (ISTM), School of Medicine, Keele University, Keele, UK
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30
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Møller AB, Lønbro S, Farup J, Voss TS, Rittig N, Wang J, Højris I, Mikkelsen UR, Jessen N. Molecular and cellular adaptations to exercise training in skeletal muscle from cancer patients treated with chemotherapy. J Cancer Res Clin Oncol 2019; 145:1449-1460. [PMID: 30968255 DOI: 10.1007/s00432-019-02911-5] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Accepted: 03/28/2019] [Indexed: 02/06/2023]
Abstract
BACKGROUND A growing body of evidence suggests that exercise training has beneficial effects in cancer patients. The aim of the present study was to investigate the molecular basis underlying these beneficial effects in skeletal muscle from cancer patients. METHODS We investigated expression of selected proteins involved in cellular processes known to orchestrate adaptation to exercise training by western blot. Skeletal muscle biopsies were sampled from ten cancer patients before and after 4-7 weeks of ongoing chemotherapy, and subsequently after 10 weeks of continued chemotherapy in combination with exercise training. Biopsies from ten healthy matched subjects served as reference. RESULTS The expression of the insulin-regulated glucose transporter, GLUT4, increased during chemotherapy and continued to increase during exercise training. A similar trend was observed for ACC, a key enzyme in the biosynthesis and oxidation of fatty acids, but we did not observe any changes in other regulators of substrate metabolism (AMPK and PDH) or mitochondrial proteins (Cyt-C, COX-IV, SDHA, and VDAC). Markers of proteasomal proteolysis (MURF1 and ATROGIN-1) decreased during chemotherapy, but did not change further during chemotherapy combined with exercise training. A similar pattern was observed for autophagy-related proteins such as ATG5, p62, and pULK1 Ser757, but not ULK1 and LC3BII/LC3BI. Phosphorylation of FOXO3a at Ser318/321 did not change during chemotherapy, but decreased during exercise training. This could suggest that FOXO3a-mediated transcriptional regulation of MURF1 and ATROGIN-1 serves as a mechanism by which exercise training maintains proteolytic systems in skeletal muscle in cancer patients. Phosphorylation of proteins that regulate protein synthesis (mTOR at Ser2448 and 4EBP1 at Thr37/46) increased during chemotherapy and leveled off during exercise training. Finally, chemotherapy tended to increase the number of satellite cells in type 1 fibers, without any further change during chemotherapy and exercise training. Conversely, the number of satellite cells in type 2 fibers did not change during chemotherapy, but increased during chemotherapy combined with exercise training. CONCLUSIONS Molecular signaling cascades involved in exercise training are disturbed during cancer and chemotherapy, and exercise training may prevent further disruption of these pathways. TRIAL REGISTRATION The study was approved by the local Scientific Ethics Committee of the Central Denmark Region (Project ID: M-2014-15-14; date of approval: 01/27/2014) and the Danish Data Protection Agency (case number 2007-58-0010; date of approval: 01/28/2015). The trial was registered at http//www.clinicaltrials.gov (registration number: NCT02192216; date of registration 07/17-2014).
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Affiliation(s)
- Andreas Buch Møller
- Research Laboratory for Biochemical Pathology, Department of Clinical Medicine, HEALTH, Aarhus University Hospital, Palle Juul-Jensen Blvd., 8200, Aarhus N, Denmark.,Steno Diabetes Center Aarhus, Aarhus University Hospital, Aarhus, Denmark
| | - Simon Lønbro
- Section of Sports Science, Department of Public Health, HEALTH, Aarhus University, Aarhus, Denmark.,Department of Experimental Clinical Oncology, Aarhus University Hospital, Aarhus, Denmark
| | - Jean Farup
- Research Laboratory for Biochemical Pathology, Department of Clinical Medicine, HEALTH, Aarhus University Hospital, Palle Juul-Jensen Blvd., 8200, Aarhus N, Denmark
| | - Thomas Schmidt Voss
- Steno Diabetes Center Aarhus, Aarhus University Hospital, Aarhus, Denmark.,Medical Research Laboratory, Department of Clinical Medicine, HEALTH, Aarhus University, Aarhus, Denmark
| | - Nikolaj Rittig
- Steno Diabetes Center Aarhus, Aarhus University Hospital, Aarhus, Denmark.,Medical Research Laboratory, Department of Clinical Medicine, HEALTH, Aarhus University, Aarhus, Denmark
| | - Jakob Wang
- Section of Sports Science, Department of Public Health, HEALTH, Aarhus University, Aarhus, Denmark
| | - Inger Højris
- Department of Oncology, Aarhus University Hospital, Aarhus, Denmark
| | - Ulla Ramer Mikkelsen
- Section of Sports Science, Department of Public Health, HEALTH, Aarhus University, Aarhus, Denmark.,Department of Orthopedic Surgery, Bispebjerg Hospital and Center for Healthy Aging, Institute of Sports Medicine, Faculty of Health Science, University of Copenhagen, Copenhagen, Denmark
| | - Niels Jessen
- Research Laboratory for Biochemical Pathology, Department of Clinical Medicine, HEALTH, Aarhus University Hospital, Palle Juul-Jensen Blvd., 8200, Aarhus N, Denmark. .,Steno Diabetes Center Aarhus, Aarhus University Hospital, Aarhus, Denmark. .,Department of Clinical Pharmacology, Aarhus University Hospital, Aarhus, Denmark.
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31
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West DWD, Marcotte GR, Chason CM, Juo N, Baehr LM, Bodine SC, Baar K. Normal Ribosomal Biogenesis but Shortened Protein Synthetic Response to Acute Eccentric Resistance Exercise in Old Skeletal Muscle. Front Physiol 2019; 9:1915. [PMID: 30692935 PMCID: PMC6339931 DOI: 10.3389/fphys.2018.01915] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Accepted: 12/18/2018] [Indexed: 01/06/2023] Open
Abstract
Anabolic resistance to feeding in aged muscle is well-characterized; however, whether old skeletal muscle is intrinsically resistant to acute mechanical loading is less clear. The aim of this study was to determine the impact of aging on muscle protein synthesis (MPS), ribosome biogenesis, and protein breakdown in skeletal muscle following a single bout of resistance exercise. Adult male F344/BN rats aged 10 (Adult) and 30 (Old) months underwent unilateral maximal eccentric contractions of the hindlimb. Precursor rRNA increased early post-exercise (6-18 h), preceding elevations in ribosomal mass at 48 h in Adult and Old; there were no age-related differences in these responses. MPS increased early post-exercise in both Adult and Old; however, at 48 h of recovery, MPS returned to baseline in Old but not Adult. This abbreviated protein synthesis response in Old was associated with decreased levels of IRS1 protein and increased BiP, CHOP and eIF2α levels. Other than these responses, anabolic signaling was similar in Adult and Old muscle in the acute recovery phase. Basal proteasome activity was lower in Old, and resistance exercise did not increase the activity of either the ATP-dependent or independent proteasome, or autophagy (Cathepsin L activity) in either Adult or Old muscle. We conclude that MPS and ribosome biogenesis in response to maximal resistance exercise in old skeletal muscle are initially intact; however, the MPS response is abbreviated in Old, which may be the result of ER stress and/or blunted exercise-induced potentiation of the MPS response to feeding.
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Affiliation(s)
- Daniel W D West
- Department of Physiology and Membrane Biology, University of California, Davis, Davis, CA, United States
| | - George R Marcotte
- Department of Neurobiology, Physiology and Behavior, University of California, Davis, Davis, CA, United States
| | - Courtney M Chason
- Department of Neurobiology, Physiology and Behavior, University of California, Davis, Davis, CA, United States
| | - Natalie Juo
- Department of Neurobiology, Physiology and Behavior, University of California, Davis, Davis, CA, United States
| | - Leslie M Baehr
- Department of Physiology and Membrane Biology, University of California, Davis, Davis, CA, United States
| | - Sue C Bodine
- Department of Physiology and Membrane Biology, University of California, Davis, Davis, CA, United States.,Department of Neurobiology, Physiology and Behavior, University of California, Davis, Davis, CA, United States.,VA Northern California Health Care System, Mather, CA, United States
| | - Keith Baar
- Department of Physiology and Membrane Biology, University of California, Davis, Davis, CA, United States.,Department of Neurobiology, Physiology and Behavior, University of California, Davis, Davis, CA, United States.,VA Northern California Health Care System, Mather, CA, United States
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32
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El-Kadi SW, Boutry C, Suryawan A, Gazzaneo MC, Orellana RA, Srivastava N, Nguyen HV, Kimball SR, Fiorotto ML, Davis TA. Intermittent bolus feeding promotes greater lean growth than continuous feeding in a neonatal piglet model. Am J Clin Nutr 2018; 108:830-841. [PMID: 30239549 PMCID: PMC6186212 DOI: 10.1093/ajcn/nqy133] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Accepted: 05/18/2018] [Indexed: 12/21/2022] Open
Abstract
Background Orogastric tube feeding is indicated in neonates with an impaired ability to ingest food normally and can be administered with an intermittent bolus or continuous feeding schedule. Objectives The objectives were to 1) compare the long-term effect of continuous with intermittent feeding on growth using the newborn pig as a model, 2) determine whether feeding frequency alters lean tissue and fat mass gain, and 3) identify the signaling mechanisms by which protein deposition is controlled in skeletal muscle in response to feeding frequency. Design Neonatal pigs were fed the same amount of a balanced formula by orogastric tube either as an intermittent bolus meal every 4 h (INT) or as a continuous infusion (CON). Body composition was assessed at the start and end of the study by dual-energy X-ray absorptiometry, and hormone and substrate profiles, muscle mass, protein synthesis, and indexes of nutrient and insulin signaling were measured after 21 d. Results Body weight, lean mass, spine length, and skeletal muscle mass were greater in the INT group than in the CON group. Skeletal muscle fractional protein synthesis rates were greater in the INT group after a meal than in the CON group and were associated with higher circulating branched-chain amino acid and insulin concentrations. Skeletal muscle protein kinase B (PKB) and ribosomal protein S6 kinase phosphorylation and eukaryotic initiation factor (eIF) 4E-eIF4G complex formation were higher, whereas eIF2α phosphorylation was lower in the INT group than in the CON group, indicating enhanced activation of insulin and amino acid signaling to translation initiation. Conclusions These results suggest that when neonates are fed the same amounts of nutrients as intermittent meals rather than continuously there is greater lean growth. This response can be ascribed, in part, to the pulsatile pattern of amino acids, insulin, or both induced by INT, which enables the responsiveness of anabolic pathways to feeding to be sustained chronically in skeletal muscle.
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Affiliation(s)
- Samer W El-Kadi
- USDA–Agricultural Research Service, Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX,Department of Animal and Poultry Sciences, Virginia Tech, Blacksburg, VA
| | - Claire Boutry
- USDA–Agricultural Research Service, Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX
| | - Agus Suryawan
- USDA–Agricultural Research Service, Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX
| | - Maria C Gazzaneo
- USDA–Agricultural Research Service, Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX
| | - Renán A Orellana
- USDA–Agricultural Research Service, Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX
| | - Neeraj Srivastava
- USDA–Agricultural Research Service, Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX
| | - Hanh V Nguyen
- USDA–Agricultural Research Service, Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX
| | - Scot R Kimball
- Department of Cellular and Molecular Physiology, Penn State College of Medicine, Hershey, PA
| | - Marta L Fiorotto
- USDA–Agricultural Research Service, Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX
| | - Teresa A Davis
- USDA–Agricultural Research Service, Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX,Address correspondence to TAD (e-mail: )
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Larsen MS, Couppé C, Møller AB, Schjerling P, Andersen JL, Nygaard RH, Langberg H, Kjaer M, Hansen M. Response to resistance training following immobilization-Influence of delaying post-exercise meal. TRANSLATIONAL SPORTS MEDICINE 2018. [DOI: 10.1002/tsm2.41] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Mads Sørensen Larsen
- Department of Public Health; Section for Sport Science; Aarhus University; Aarhus Denmark
| | - Christian Couppé
- Department of Orthopaedic Surgery M; Faculty of Health and Medical Sciences; Institute of Sports Medicine; Bispebjerg Hospital & Center for Healthy Aging; University of Copenhagen; Copenhagen Denmark
- Department of Physical Therapy; Musculoskeletal Rehabilitation Research Unit; Bispebjerg Hospital; Copenhagen Denmark
| | - Andreas Buch Møller
- Research Laboratory for Biochemical Pathology; Department of Clinical Medicine; Aarhus University; Aarhus Denmark
| | - Peter Schjerling
- Department of Orthopaedic Surgery M; Faculty of Health and Medical Sciences; Institute of Sports Medicine; Bispebjerg Hospital & Center for Healthy Aging; University of Copenhagen; Copenhagen Denmark
- Department of Physical Therapy; Musculoskeletal Rehabilitation Research Unit; Bispebjerg Hospital; Copenhagen Denmark
| | - Jesper Løvind Andersen
- Department of Orthopaedic Surgery M; Faculty of Health and Medical Sciences; Institute of Sports Medicine; Bispebjerg Hospital & Center for Healthy Aging; University of Copenhagen; Copenhagen Denmark
- Department of Physical Therapy; Musculoskeletal Rehabilitation Research Unit; Bispebjerg Hospital; Copenhagen Denmark
| | - Rie Harboe Nygaard
- Department of Orthopaedic Surgery M; Faculty of Health and Medical Sciences; Institute of Sports Medicine; Bispebjerg Hospital & Center for Healthy Aging; University of Copenhagen; Copenhagen Denmark
- Department of Physical Therapy; Musculoskeletal Rehabilitation Research Unit; Bispebjerg Hospital; Copenhagen Denmark
| | - Henning Langberg
- Department of Orthopaedic Surgery M; Faculty of Health and Medical Sciences; Institute of Sports Medicine; Bispebjerg Hospital & Center for Healthy Aging; University of Copenhagen; Copenhagen Denmark
- Department of Physical Therapy; Musculoskeletal Rehabilitation Research Unit; Bispebjerg Hospital; Copenhagen Denmark
| | - Michael Kjaer
- Department of Orthopaedic Surgery M; Faculty of Health and Medical Sciences; Institute of Sports Medicine; Bispebjerg Hospital & Center for Healthy Aging; University of Copenhagen; Copenhagen Denmark
- Department of Physical Therapy; Musculoskeletal Rehabilitation Research Unit; Bispebjerg Hospital; Copenhagen Denmark
| | - Mette Hansen
- Department of Orthopaedic Surgery M; Faculty of Health and Medical Sciences; Institute of Sports Medicine; Bispebjerg Hospital & Center for Healthy Aging; University of Copenhagen; Copenhagen Denmark
- Department of Physical Therapy; Musculoskeletal Rehabilitation Research Unit; Bispebjerg Hospital; Copenhagen Denmark
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Moberg M, Hendo G, Jakobsson M, Mattsson CM, Ekblom-Bak E, Flockhart M, Pontén M, Söderlund K, Ekblom B. Increased autophagy signaling but not proteasome activity in human skeletal muscle after prolonged low-intensity exercise with negative energy balance. Physiol Rep 2018; 5. [PMID: 29208687 PMCID: PMC5727276 DOI: 10.14814/phy2.13518] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Accepted: 11/02/2017] [Indexed: 01/01/2023] Open
Abstract
Little is known about the molecular regulation of skeletal muscle protein turnover during exercise in field conditions where energy is intake inadequate. Here, 17 male and 7 female soldiers performed an 8 days long field-based military operation. Vastus lateralis muscle biopsies, in which autophagy, the ubiquitin-proteasome system, and the mTORC1 signaling pathway were studied, were collected before and after the operation. The 187 h long operation resulted in a 15% and 29% negative energy balance as well as a 4.1% and 4.6% loss of body mass in women and men, respectively. After the operation protein levels of ULK1 as well as the phosphorylation of ULK1Ser317 and ULK1Ser555 had increased by 11%, 39%, and 13%, respectively, and this was supported by a 17% increased phosphorylation of AMPKThr172 (P < 0.05). The LC3b-I/II ratio was threefold higher after compared to before the operation (P < 0.05), whereas protein levels of p62/SQSTM1 were unchanged. The β1, β2, and β5 activity of the proteasome and protein levels of MAFbx did not change, whereas levels of MuRF-1 were slightly reduced (6%, P < 0.05). Protein levels and phosphorylation status of key components in the mTORC1 signaling pathway remained at basal levels after the operation. Muscle levels of glycogen decreased from 269 ± 12 to 181 ± 9 mmol·kg dry·muscle-1 after the exercise period (P < 0.05). In conclusion, the 8 days of field-based exercise resulted in induction of autophagy without any increase in proteasome activity or protein ubiquitination. Simultaneously, the regulation of protein synthesis through the mTORC1 signaling pathway was maintained.
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Affiliation(s)
- Marcus Moberg
- Åstrand Laboratory of Work Physiology, the Swedish School of Sport and Health Sciences, Stockholm, Sweden
| | - Gina Hendo
- Åstrand Laboratory of Work Physiology, the Swedish School of Sport and Health Sciences, Stockholm, Sweden
| | - Madelene Jakobsson
- Åstrand Laboratory of Work Physiology, the Swedish School of Sport and Health Sciences, Stockholm, Sweden
| | - C Mikael Mattsson
- Åstrand Laboratory of Work Physiology, the Swedish School of Sport and Health Sciences, Stockholm, Sweden
| | - Elin Ekblom-Bak
- Åstrand Laboratory of Work Physiology, the Swedish School of Sport and Health Sciences, Stockholm, Sweden
| | - Mikael Flockhart
- Åstrand Laboratory of Work Physiology, the Swedish School of Sport and Health Sciences, Stockholm, Sweden
| | - Marjan Pontén
- Åstrand Laboratory of Work Physiology, the Swedish School of Sport and Health Sciences, Stockholm, Sweden
| | - Karin Söderlund
- Åstrand Laboratory of Work Physiology, the Swedish School of Sport and Health Sciences, Stockholm, Sweden
| | - Björn Ekblom
- Åstrand Laboratory of Work Physiology, the Swedish School of Sport and Health Sciences, Stockholm, Sweden
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You JS, Dooley MS, Kim CR, Kim EJ, Xu W, Goodman CA, Hornberger TA. A DGKζ-FoxO-ubiquitin proteolytic axis controls fiber size during skeletal muscle remodeling. Sci Signal 2018; 11:11/530/eaao6847. [PMID: 29764991 DOI: 10.1126/scisignal.aao6847] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Skeletal muscle rapidly remodels in response to various stresses, and the resulting changes in muscle mass profoundly influence our health and quality of life. We identified a diacylglycerol kinase ζ (DGKζ)-mediated pathway that regulated muscle mass during remodeling. During mechanical overload, DGKζ abundance was increased and required for effective hypertrophy. DGKζ not only augmented anabolic responses but also suppressed ubiquitin-proteasome system (UPS)-dependent proteolysis. We found that DGKζ inhibited the transcription factor FoxO that promotes the induction of the UPS. This function was mediated through a mechanism that was independent of kinase activity but dependent on the nuclear localization of DGKζ. During denervation, DGKζ abundance was also increased and was required for mitigating the activation of FoxO-UPS and the induction of atrophy. Conversely, overexpression of DGKζ prevented fasting-induced atrophy. Therefore, DGKζ is an inhibitor of the FoxO-UPS pathway, and interventions that increase its abundance could prevent muscle wasting.
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Affiliation(s)
- Jae-Sung You
- Program in Cellular and Molecular Biology, University of Wisconsin-Madison, 2015 Linden Drive, Madison, WI 53706, USA. .,Department of Comparative Biosciences in the School of Veterinary Medicine, University of Wisconsin-Madison, 2015 Linden Drive, Madison, WI 53706, USA.,Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, 601 South Goodwin Avenue, Urbana, IL 61801, USA
| | - Matthew S Dooley
- Department of Comparative Biosciences in the School of Veterinary Medicine, University of Wisconsin-Madison, 2015 Linden Drive, Madison, WI 53706, USA
| | - Chan-Ran Kim
- Department of Comparative Biosciences in the School of Veterinary Medicine, University of Wisconsin-Madison, 2015 Linden Drive, Madison, WI 53706, USA
| | - Eui-Jun Kim
- McArdle Laboratory for Cancer Research, University of Wisconsin-Madison, 1111 Highland Avenue, Madison, WI 53705, USA
| | - Wei Xu
- McArdle Laboratory for Cancer Research, University of Wisconsin-Madison, 1111 Highland Avenue, Madison, WI 53705, USA
| | - Craig A Goodman
- Department of Comparative Biosciences in the School of Veterinary Medicine, University of Wisconsin-Madison, 2015 Linden Drive, Madison, WI 53706, USA.,College of Health and Biomedicine, Victoria University, Melbourne, Victoria 8001, Australia.,Institute for Sport, Exercise and Active Living, Victoria University, Melbourne, Victoria 8001, Australia.,Australian Institute of Musculoskeletal Science, Victoria University, St. Albans, Victoria 3021, Australia
| | - Troy A Hornberger
- Program in Cellular and Molecular Biology, University of Wisconsin-Madison, 2015 Linden Drive, Madison, WI 53706, USA. .,Department of Comparative Biosciences in the School of Veterinary Medicine, University of Wisconsin-Madison, 2015 Linden Drive, Madison, WI 53706, USA
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36
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Ceelen JJM, Schols AMWJ, Thielen NGM, Haegens A, Gray DA, Kelders MCJM, de Theije CC, Langen RCJ. Pulmonary inflammation-induced loss and subsequent recovery of skeletal muscle mass require functional poly-ubiquitin conjugation. Respir Res 2018; 19:80. [PMID: 29720191 PMCID: PMC5932886 DOI: 10.1186/s12931-018-0753-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Accepted: 03/18/2018] [Indexed: 01/24/2023] Open
Abstract
BACKGROUND Pulmonary inflammation in response to respiratory infections can evoke muscle wasting. Increased activity of the ubiquitin (Ub)-proteasome system (UPS) and the autophagy lysosome pathway (ALP) have been implicated in inflammation-induced muscle atrophy. Since poly-Ub conjugation is required for UPS-mediated proteolysis and has been implicated in the ALP, we assessed the effect of impaired ubiquitin conjugation on muscle atrophy and recovery following pulmonary inflammation, and compared activation and suppression of these proteolytic systems to protein synthesis regulation. METHODS Pulmonary inflammation was induced in mice by an intratracheal instillation of LPS. Proteolysis (UPS and ALP) and synthesis signaling were examined in gastrocnemius muscle homogenates. Ub-conjugation-dependency of muscle atrophy and recovery was addressed using Ub-K48R (K48R) mice with attenuated poly-ubiquitin conjugation, and compared to UBWT control mice. RESULTS Pulmonary inflammation caused a decrease in skeletal muscle mass which was accompanied by a rapid increase in expression of UPS and ALP constituents and reduction in protein synthesis signaling acutely after LPS. Muscle atrophy was attenuated in K48R mice, while ALP and protein synthesis signaling were not affected. Muscle mass recovery starting 72 h post LPS, correlated with reduced expression of UPS and ALP constituents and restoration of protein synthesis signaling. K48R mice however displayed impaired recovery of muscle mass. CONCLUSION Pulmonary inflammation-induced muscle atrophy is in part attributable to UPS-mediated proteolysis, as activation of ALP- and suppression of protein synthesis signaling occur independently of poly-Ub conjugation during muscle atrophy. Recovery of muscle mass following pulmonary inflammation involves inverse regulation of proteolysis and protein synthesis signaling, and requires a functional poly-Ub conjugation.
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Affiliation(s)
- Judith J. M. Ceelen
- Department of Respiratory Medicine, School of Nutrition and Translational Research in Metabolism (NUTRIM), Maastricht University Medical Centre (MUMC+), Maastricht, the Netherlands
| | - Annemie M. W. J. Schols
- Department of Respiratory Medicine, School of Nutrition and Translational Research in Metabolism (NUTRIM), Maastricht University Medical Centre (MUMC+), Maastricht, the Netherlands
| | - Nathalie G. M. Thielen
- Department of Respiratory Medicine, School of Nutrition and Translational Research in Metabolism (NUTRIM), Maastricht University Medical Centre (MUMC+), Maastricht, the Netherlands
| | - Astrid Haegens
- Department of Respiratory Medicine, School of Nutrition and Translational Research in Metabolism (NUTRIM), Maastricht University Medical Centre (MUMC+), Maastricht, the Netherlands
| | - Douglas A. Gray
- Department of Biochemistry, Microbiology and Immunology, Ottawa Hospital Research Institute, Ottawa, Canada
| | - Marco C. J. M. Kelders
- Department of Respiratory Medicine, School of Nutrition and Translational Research in Metabolism (NUTRIM), Maastricht University Medical Centre (MUMC+), Maastricht, the Netherlands
| | - Chiel C. de Theije
- Department of Respiratory Medicine, School of Nutrition and Translational Research in Metabolism (NUTRIM), Maastricht University Medical Centre (MUMC+), Maastricht, the Netherlands
| | - Ramon C. J. Langen
- Department of Respiratory Medicine, School of Nutrition and Translational Research in Metabolism (NUTRIM), Maastricht University Medical Centre (MUMC+), Maastricht, the Netherlands
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Fortes MAS, Scervino MVM, Marzuca-Nassr GN, Vitzel KF, da Justa Pinheiro CH, Curi R. Hypertrophy Stimulation at the Onset of Type I Diabetes Maintains the Soleus but Not the EDL Muscle Mass in Wistar Rats. Front Physiol 2017; 8:830. [PMID: 29123487 PMCID: PMC5662641 DOI: 10.3389/fphys.2017.00830] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Accepted: 10/06/2017] [Indexed: 12/17/2022] Open
Abstract
Diabetes mellitus induces a reduction in skeletal muscle mass and strength. Strength training is prescribed as part of treatment since it improves glycemic control and promotes increase of skeletal muscle mass. The mechanisms involved in overload-induced muscle hypertrophy elicited at the establishment of the type I diabetic state was investigated in Wistar rats. The purpose was to examine whether the overload-induced hypertrophy can counteract the hypotrophy associated to the diabetic state. The experiments were performed in oxidative (soleus) or glycolytic (EDL) muscles. PI3K/Akt/mTOR protein synthesis pathway was evaluated 7 days after overload-induced hypertrophy of soleus and of EDL muscles. The mRNA expression of genes associated with different signaling pathways that control muscle hypertrophy was also evaluated: mechanotransduction (FAK), Wnt/β-catenin, myostatin, and follistatin. The soleus and EDL muscles when submitted to overload had similar hypertrophic responses in control and diabetic animals. The increase of absolute and specific twitch and tetanic forces had the same magnitude as muscle hypertrophic response. Hypertrophy of the EDL muscle from diabetic animals mostly involved mechanical loading-stimulated PI3K/Akt/mTOR pathway besides the reduced activation of AMP-activated protein kinase (AMPK) and decrease of myostatin expression. Hypertrophy was more pronounced in the soleus muscle of diabetic animals due to a more potent activation of rpS6 and increased mRNA expression of insulin-like growth factor-1 (IGF-1), mechano-growth factor (MGF) and follistatin, and decrease of myostatin, MuRF-1 and atrogin-1 contents. The signaling changes enabled the soleus muscle mass and force of the diabetic rats to reach the values of the control group.
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Affiliation(s)
- Marco A S Fortes
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Maria V M Scervino
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Gabriel N Marzuca-Nassr
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil.,Department of Internal Medicine, Faculty of Medicine, Universidad de La Frontera, Temuco, Chile
| | - Kaio F Vitzel
- School of Health Sciences, College of Health, Massey University, Albany, New Zealand
| | - Carlos H da Justa Pinheiro
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Rui Curi
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil.,Interdisciplinary Post-Graduate Program in Health Sciences, Cruzeiro do Sul University, São Paulo, Brazil
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38
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Pereira RO, Tadinada SM, Zasadny FM, Oliveira KJ, Pires KMP, Olvera A, Jeffers J, Souvenir R, Mcglauflin R, Seei A, Funari T, Sesaki H, Potthoff MJ, Adams CM, Anderson EJ, Abel ED. OPA1 deficiency promotes secretion of FGF21 from muscle that prevents obesity and insulin resistance. EMBO J 2017; 36:2126-2145. [PMID: 28607005 PMCID: PMC5510002 DOI: 10.15252/embj.201696179] [Citation(s) in RCA: 145] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2016] [Revised: 05/08/2017] [Accepted: 05/09/2017] [Indexed: 12/21/2022] Open
Abstract
Mitochondrial dynamics is a conserved process by which mitochondria undergo repeated cycles of fusion and fission, leading to exchange of mitochondrial genetic content, ions, metabolites, and proteins. Here, we examine the role of the mitochondrial fusion protein optic atrophy 1 (OPA1) in differentiated skeletal muscle by reducing OPA1 gene expression in an inducible manner. OPA1 deficiency in young mice results in non-lethal progressive mitochondrial dysfunction and loss of muscle mass. Mutant mice are resistant to age- and diet-induced weight gain and insulin resistance, by mechanisms that involve activation of ER stress and secretion of fibroblast growth factor 21 (FGF21) from skeletal muscle, resulting in increased metabolic rates and improved whole-body insulin sensitivity. OPA1-elicited mitochondrial dysfunction activates an integrated stress response that locally induces muscle atrophy, but via secretion of FGF21 acts distally to modulate whole-body metabolism.
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Affiliation(s)
- Renata Oliveira Pereira
- Fraternal Order of Eagles Diabetes Research Center and Division of Endocrinology and Metabolism, Roy J. and Lucille A. Carver College of Medicine University of Iowa, Iowa City, IA, USA
| | - Satya M Tadinada
- Fraternal Order of Eagles Diabetes Research Center and Division of Endocrinology and Metabolism, Roy J. and Lucille A. Carver College of Medicine University of Iowa, Iowa City, IA, USA
| | - Frederick M Zasadny
- Fraternal Order of Eagles Diabetes Research Center and Division of Endocrinology and Metabolism, Roy J. and Lucille A. Carver College of Medicine University of Iowa, Iowa City, IA, USA
| | - Karen Jesus Oliveira
- Division of Endocrinology, Metabolism and Diabetes, and Program in Molecular Medicine, University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Karla Maria Pereira Pires
- Division of Endocrinology, Metabolism and Diabetes, and Program in Molecular Medicine, University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Angela Olvera
- Fraternal Order of Eagles Diabetes Research Center and Division of Endocrinology and Metabolism, Roy J. and Lucille A. Carver College of Medicine University of Iowa, Iowa City, IA, USA
| | - Jennifer Jeffers
- Fraternal Order of Eagles Diabetes Research Center and Division of Endocrinology and Metabolism, Roy J. and Lucille A. Carver College of Medicine University of Iowa, Iowa City, IA, USA
| | - Rhonda Souvenir
- Fraternal Order of Eagles Diabetes Research Center and Division of Endocrinology and Metabolism, Roy J. and Lucille A. Carver College of Medicine University of Iowa, Iowa City, IA, USA
| | - Rose Mcglauflin
- Fraternal Order of Eagles Diabetes Research Center and Division of Endocrinology and Metabolism, Roy J. and Lucille A. Carver College of Medicine University of Iowa, Iowa City, IA, USA
| | - Alec Seei
- Fraternal Order of Eagles Diabetes Research Center and Division of Endocrinology and Metabolism, Roy J. and Lucille A. Carver College of Medicine University of Iowa, Iowa City, IA, USA
| | - Trevor Funari
- Fraternal Order of Eagles Diabetes Research Center and Division of Endocrinology and Metabolism, Roy J. and Lucille A. Carver College of Medicine University of Iowa, Iowa City, IA, USA
| | - Hiromi Sesaki
- Department of Cell Biology, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - Matthew J Potthoff
- Fraternal Order of Eagles Diabetes Research Center and Division of Endocrinology and Metabolism, Roy J. and Lucille A. Carver College of Medicine University of Iowa, Iowa City, IA, USA
- Department of Pharmacology, Roy J. and Lucille A. Carver College of Medicine University of Iowa, Iowa City, IA, USA
| | - Christopher M Adams
- Fraternal Order of Eagles Diabetes Research Center and Division of Endocrinology and Metabolism, Roy J. and Lucille A. Carver College of Medicine University of Iowa, Iowa City, IA, USA
| | - Ethan J Anderson
- Fraternal Order of Eagles Diabetes Research Center and Division of Endocrinology and Metabolism, Roy J. and Lucille A. Carver College of Medicine University of Iowa, Iowa City, IA, USA
- College of Pharmacy, University of Iowa, Iowa City, IA, USA
| | - E Dale Abel
- Fraternal Order of Eagles Diabetes Research Center and Division of Endocrinology and Metabolism, Roy J. and Lucille A. Carver College of Medicine University of Iowa, Iowa City, IA, USA
- Division of Endocrinology, Metabolism and Diabetes, and Program in Molecular Medicine, University of Utah School of Medicine, Salt Lake City, UT, USA
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Baehr LM, West DWD, Marshall AG, Marcotte GR, Baar K, Bodine SC. Muscle-specific and age-related changes in protein synthesis and protein degradation in response to hindlimb unloading in rats. J Appl Physiol (1985) 2017; 122:1336-1350. [PMID: 28336537 DOI: 10.1152/japplphysiol.00703.2016] [Citation(s) in RCA: 73] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Revised: 02/16/2017] [Accepted: 02/26/2017] [Indexed: 12/19/2022] Open
Abstract
Disuse is a potent inducer of muscle atrophy, but the molecular mechanisms driving this loss of muscle mass are highly debated. In particular, the extent to which disuse triggers decreases in protein synthesis or increases in protein degradation, and whether these changes are uniform across muscles or influenced by age, is unclear. We aimed to determine the impact of disuse on protein synthesis and protein degradation in lower limb muscles of varied function and fiber type in adult and old rats. Alterations in protein synthesis and degradation were measured in the soleus, medial gastrocnemius, and tibialis anterior (TA) muscles of adult and old rats subjected to hindlimb unloading (HU) for 3, 7, or 14 days. Loss of muscle mass was progressive during the unloading period, but highly variable (-9 to -38%) across muscle types and between ages. Protein synthesis decreased significantly in all muscles, except for the old TA. Atrophy-associated gene expression was only loosely associated with protein degradation as muscle RING finger-1, muscle atrophy F-box (MAFbx), and Forkhead box O1 expression significantly increased in all muscles, but an increase in proteasome activity was only observed in the adult soleus. MAFbx protein levels were significantly higher in the old muscles compared with adult muscles, despite the old having higher expression of microRNA-23a. These results indicate that adult and old muscles respond similarly to HU, and the greatest loss in muscle mass occurs in predominantly slow-twitch extensor muscles due to a concomitant decrease in protein synthesis and increase in protein degradation.NEW & NOTEWORTHY In this study, we showed that age did not intensify the atrophy response to unloading in rats, but rather that the degree of atrophy was highly variable across muscles, indicating that changes in protein synthesis and protein degradation occur in a muscle-specific manner. Our data emphasize the importance of studying muscles of varying fiber-type and physiological function at multiple time points to fully understand the molecular mechanisms responsible for disuse atrophy.
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Affiliation(s)
- Leslie M Baehr
- Veterans Affairs Northern California Health Care System, Mather, California.,Department of Physiology and Membrane Biology, University of California Davis, Davis, California; and
| | - Daniel W D West
- Veterans Affairs Northern California Health Care System, Mather, California.,Department of Physiology and Membrane Biology, University of California Davis, Davis, California; and
| | - Andrea G Marshall
- Department of Physiology and Membrane Biology, University of California Davis, Davis, California; and
| | - George R Marcotte
- Veterans Affairs Northern California Health Care System, Mather, California
| | - Keith Baar
- Veterans Affairs Northern California Health Care System, Mather, California.,Department of Physiology and Membrane Biology, University of California Davis, Davis, California; and.,Department of Neurobiology, Physiology and Behavior, University of California Davis, Davis, California
| | - Sue C Bodine
- Veterans Affairs Northern California Health Care System, Mather, California; .,Department of Physiology and Membrane Biology, University of California Davis, Davis, California; and.,Department of Neurobiology, Physiology and Behavior, University of California Davis, Davis, California
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40
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Sakuma K, Aoi W, Yamaguchi A. Molecular mechanism of sarcopenia and cachexia: recent research advances. Pflugers Arch 2017; 469:573-591. [PMID: 28101649 DOI: 10.1007/s00424-016-1933-3] [Citation(s) in RCA: 94] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Revised: 12/28/2016] [Accepted: 12/29/2016] [Indexed: 12/17/2022]
Abstract
Skeletal muscle provides a fundamental basis for human function, enabling locomotion and respiration. Muscle loss occurs as a consequence of several chronic diseases (cachexia) and normal aging (sarcopenia). Although many negative regulators (atrogin-1, muscle ring finger-1, nuclear factor-kappaB (NF-κB), myostatin, etc.) have been proposed to enhance protein degradation during both sarcopenia and cachexia, the adaptation of these mediators markedly differs within both conditions. Sarcopenia and cachectic muscles have been demonstrated to be abundant in myostatin-linked molecules. The ubiquitin-proteasome system (UPS) is activated during rapid atrophy model (cancer cachexia), but few mediators of the UPS change during sarcopenia. NF-κB signaling is activated in cachectic, but not in sarcopenic, muscle. Recent studies have indicated the age-related defect of autophagy signaling in skeletal muscle, whereas autophagic activation occurs in cachectic muscle. This review provides recent research advances dealing with molecular mediators modulating muscle mass in both sarcopenia and cachexia.
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Affiliation(s)
- Kunihiro Sakuma
- Institute for Liberal Arts, Environment and Society, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo, 152-8550, Japan.
| | - Wataru Aoi
- Laboratory of Health Science, Graduate School of Life and Environmental Sciences, Kyoto Prefectural University, 1-5 Hangi-cho Shimogamo, Sakyo-ku, Kyoto, 606-8522, Japan
| | - Akihiko Yamaguchi
- Department of Physical Therapy, Health Sciences University of Hokkaido, Kanazawa, Ishikari-Tobetsu, Hokkaido, 061-0293, Japan
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41
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Age-related deficits in skeletal muscle recovery following disuse are associated with neuromuscular junction instability and ER stress, not impaired protein synthesis. Aging (Albany NY) 2016; 8:127-46. [PMID: 26826670 PMCID: PMC4761718 DOI: 10.18632/aging.100879] [Citation(s) in RCA: 138] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Age-related loss of muscle mass and strength can be accelerated by impaired recovery of muscle mass following a transient atrophic stimulus. The aim of this study was to identify the mechanisms underlying the attenuated recovery of muscle mass and strength in old rats following disuse-induced atrophy. Adult (9 month) and old (29 month) male F344BN rats underwent hindlimb unloading (HU) followed by reloading. HU induced significant atrophy of the hindlimb muscles in both adult (17-38%) and old (8-29%) rats, but only the adult rats exhibited full recovery of muscle mass and strength upon reloading. Upon reloading, total RNA and protein synthesis increased to a similar extent in adult and old muscles. At baseline and upon reloading, however, proteasome-mediated degradation was suppressed leading to an accumulation of ubiquitin-tagged proteins and p62. Further, ER stress, as measured by CHOP expression, was elevated at baseline and upon reloading in old rats. Analysis of mRNA expression revealed increases in HDAC4, Runx1, myogenin, Gadd45a, and the AChRs in old rats, suggesting neuromuscular junction instability/denervation. Collectively, our data suggests that with aging, impaired neuromuscular transmission and deficits in the proteostasis network contribute to defects in muscle fiber remodeling and functional recovery of muscle mass and strength.
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42
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Steiner JL, Fukuda DH, Rossetti ML, Hoffman JR, Gordon BS. Castration alters protein balance after high-frequency muscle contraction. J Appl Physiol (1985) 2016; 122:264-272. [PMID: 27909227 DOI: 10.1152/japplphysiol.00740.2016] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Revised: 11/07/2016] [Accepted: 11/23/2016] [Indexed: 01/07/2023] Open
Abstract
Resistance exercise increases muscle mass by shifting protein balance in favor of protein accretion. Androgens independently alter protein balance, but it is unknown whether androgens alter this measure after resistance exercise. To answer this, male mice were subjected to sham or castration surgery 7-8 wk before undergoing a bout of unilateral, high-frequency, electrically induced muscle contractions in the fasted or refed state. Puromycin was injected 30 min before euthanasia to measure protein synthesis. The tibialis anterior was analyzed 4 h postcontraction. In fasted mice, neither basal nor stimulated rates of protein synthesis were affected by castration despite lower phosphorylation of mechanistic target of rapamycin in complex 1 (mTORC1) substrates [p70S6K1 (Thr389) and 4E-BP1 (Ser65)]. Markers of autophagy (LC3 II/I ratio and p62 protein content) were elevated by castration, and these measures remained elevated above sham values after contractions. Furthermore, in fasted mice, the protein content of Regulated in Development and DNA Damage 1 (REDD1) was correlated with LC3 II/I in noncontracted muscle, whereas phosphorylation of uncoordinated like kinase 1 (ULK1) (Ser757) was correlated with LC3 II/I in the contracted muscle. When mice were refed before contractions, protein synthesis and mTORC1 signaling were not affected by castration in either the noncontracted or contracted muscle. Conversely, markers of autophagy remained elevated in the muscles of refed, castrated mice even after contractions. These data suggest the castration-mediated elevation in baseline autophagy reduces the absolute positive shift in protein balance after muscle contractions in the refed or fasted states. NEW & NOTEWORTHY In the absence of androgens, markers of autophagy were elevated, and these could not be normalized by muscle contractions. In the fasted state, REDD1 was identified as a potential contributor to autophagy in noncontracted muscle, whereas phosphorylation of ULK1 may contribute to this process in the contracted muscle. In the refed state, markers of autophagy remain elevated in both noncontracted and contracted muscles, but the relationship with REDD1 and ULK1 (Ser757) no longer existed.
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Affiliation(s)
- Jennifer L Steiner
- Department of Cellular and Molecular Physiology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania
| | - David H Fukuda
- Institute of Exercise Physiology and Wellness, The University of Central Florida, Orlando, Florida; and
| | - Michael L Rossetti
- Institute of Exercise Physiology and Wellness, The University of Central Florida, Orlando, Florida; and
| | - Jay R Hoffman
- Institute of Exercise Physiology and Wellness, The University of Central Florida, Orlando, Florida; and.,Burnett School of Biomedical Sciences, The University of Central Florida, Orlando, Florida
| | - Bradley S Gordon
- Institute of Exercise Physiology and Wellness, The University of Central Florida, Orlando, Florida; and
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Anderson MJ, Diko S, Baehr LM, Baar K, Bodine SC, Christiansen BA. Contribution of mechanical unloading to trabecular bone loss following non-invasive knee injury in mice. J Orthop Res 2016; 34:1680-1687. [PMID: 26826014 PMCID: PMC5603199 DOI: 10.1002/jor.23178] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Accepted: 01/28/2016] [Indexed: 02/04/2023]
Abstract
Development of osteoarthritis commonly involves degeneration of epiphyseal trabecular bone. In previous studies, we observed 30-44% loss of epiphyseal trabecular bone (BV/TV) from the distal femur within 1 week following non-invasive knee injury in mice. Mechanical unloading (disuse) may contribute to this bone loss; however, it is unclear to what extent the injured limb is unloaded following injury, and whether disuse can fully account for the observed magnitude of bone loss. In this study, we investigated the contribution of mechanical unloading to trabecular bone changes observed following non-invasive knee injury in mice (female C57BL/6N). We investigated changes in gait during treadmill walking, and changes in voluntary activity level using Open Field analysis at 4, 14, 28, and 42 days post-injury. We also quantified epiphyseal trabecular bone using μCT and weighed lower-limb muscles to quantify atrophy following knee injury in both ground control and hindlimb unloaded (HLU) mice. Gait analysis revealed a slightly altered stride pattern in the injured limb, with a decreased stance phase and increased swing phase. However, Open Field analysis revealed no differences in voluntary movement between injured and sham mice at any time point. Both knee injury and HLU resulted in comparable magnitudes of trabecular bone loss; however, HLU resulted in considerably more muscle loss than knee injury, suggesting another mechanism contributing to bone loss following injury. Altogether, these data suggest that mechanical unloading likely contributes to trabecular bone loss following non-invasive knee injury, but the magnitude of this bone loss cannot be fully explained by disuse. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:1680-1687, 2016.
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Affiliation(s)
- Matthew J. Anderson
- University of California-Davis Medical Center, Department of Orthopaedic Surgery
| | - Sindi Diko
- University of California-Davis Medical Center, Department of Orthopaedic Surgery
| | - Leslie M. Baehr
- University of California-Davis, Department of Neurobiology, Physiology, and Behavior; Department of Physiology and Membrane Biology
| | - Keith Baar
- University of California-Davis, Department of Neurobiology, Physiology, and Behavior; Department of Physiology and Membrane Biology
| | - Sue C. Bodine
- University of California-Davis, Department of Neurobiology, Physiology, and Behavior; Department of Physiology and Membrane Biology
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44
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Disrupted autophagy undermines skeletal muscle adaptation and integrity. Mamm Genome 2016; 27:525-537. [PMID: 27484057 PMCID: PMC5110612 DOI: 10.1007/s00335-016-9659-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Accepted: 07/12/2016] [Indexed: 12/18/2022]
Abstract
This review assesses the importance of proteostasis in skeletal muscle maintenance with a specific emphasis on autophagy. Skeletal muscle appears to be particularly vulnerable to genetic defects in basal and induced autophagy, indicating that autophagy is co-substantial to skeletal muscle maintenance and adaptation. We discuss emerging evidence that tension-induced protein unfolding may act as a direct link between mechanical stress and autophagic pathways. Mechanistic links between protein damage, autophagy and muscle hypertrophy, which is also induced by mechanical stress, are still poorly understood. However, some mouse models of muscle disease show ameliorated symptoms upon effective targeting of basal autophagy. These findings highlight the importance of autophagy as therapeutic target and suggest that elucidating connections between protein unfolding and mTOR-dependent or mTOR-independent hypertrophic responses is likely to reveal specific therapeutic windows for the treatment of muscle wasting disorders.
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Bell RAV, Al-Khalaf M, Megeney LA. The beneficial role of proteolysis in skeletal muscle growth and stress adaptation. Skelet Muscle 2016; 6:16. [PMID: 27054028 PMCID: PMC4822268 DOI: 10.1186/s13395-016-0086-6] [Citation(s) in RCA: 76] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Accepted: 03/17/2016] [Indexed: 12/17/2022] Open
Abstract
Muscle atrophy derived from excessive proteolysis is a hallmark of numerous disease conditions. Accordingly, the negative consequences of skeletal muscle protein breakdown often overshadow the critical nature of proteolytic systems in maintaining normal cellular function. Here, we discuss the major cellular proteolysis machinery-the ubiquitin/proteosome system, the autophagy/lysosomal system, and caspase-mediated protein cleavage-and the critical role of these protein machines in establishing and preserving muscle health. We examine how ordered degradation modifies (1) the spatiotemporal expression of myogenic regulatory factors during myoblast differentiation, (2) membrane fusion during myotube formation, (3) sarcomere remodeling and muscle growth following physical stress, and (4) energy homeostasis during nutrient deprivation. Finally, we review the origin and etiology of a number of myopathies and how these devastating conditions arise from inborn errors in proteolysis.
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Affiliation(s)
- Ryan A V Bell
- Regenerative Medicine Program, Sprott Center for Stem Cell Research, Ottawa Hospital Research Institute, The Ottawa Hospital, Ottawa, ON K1H 8L6 Canada ; Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON Canada
| | - Mohammad Al-Khalaf
- Regenerative Medicine Program, Sprott Center for Stem Cell Research, Ottawa Hospital Research Institute, The Ottawa Hospital, Ottawa, ON K1H 8L6 Canada ; Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON Canada
| | - Lynn A Megeney
- Regenerative Medicine Program, Sprott Center for Stem Cell Research, Ottawa Hospital Research Institute, The Ottawa Hospital, Ottawa, ON K1H 8L6 Canada ; Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON Canada ; Department of Medicine, Division of Cardiology, University of Ottawa, Ottawa, ON Canada
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West DWD, Baehr LM, Marcotte GR, Chason CM, Tolento L, Gomes AV, Bodine SC, Baar K. Acute resistance exercise activates rapamycin-sensitive and -insensitive mechanisms that control translational activity and capacity in skeletal muscle. J Physiol 2015; 594:453-68. [PMID: 26548696 DOI: 10.1113/jp271365] [Citation(s) in RCA: 108] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Accepted: 10/29/2015] [Indexed: 12/19/2022] Open
Abstract
KEY POINTS Ribosome biogenesis is the primary determinant of translational capacity, but its regulation in skeletal muscle following acute resistance exercise is poorly understood. Resistance exercise increases muscle protein synthesis acutely, and muscle mass with training, but the role of translational capacity in these processes is unclear. Here, we show that acute resistance exercise activated pathways controlling translational activity and capacity through both rapamycin-sensitive and -insensitive mechanisms. Transcription factor c-Myc and its downstream targets, which are known to regulate ribosome biogenesis in other cell types, were upregulated after resistance exercise in a rapamycin-independent manner and may play a role in determining translational capacity in skeletal muscle. Local inhibition of myostatin was also not affected by rapamycin and may contribute to the rapamycin-independent effects of resistance exercise. ABSTRACT This study aimed to determine (1) the effect of acute resistance exercise on mechanisms of ribosome biogenesis, and (2) the impact of mammalian target of rapamycin on ribosome biogenesis, and muscle protein synthesis (MPS) and degradation. Female F344BN rats underwent unilateral electrical stimulation of the sciatic nerve to mimic resistance exercise in the tibialis anterior (TA) muscle. TA muscles were collected at intervals over the 36 h of exercise recovery (REx); separate groups of animals were administered rapamycin pre-exercise (REx+Rapamycin). Resistance exercise led to a prolonged (6-36 h) elevation (30-50%) of MPS that was fully blocked by rapamycin at 6 h but only partially at 18 h. REx also altered pathways that regulate protein homeostasis and mRNA translation in a manner that was both rapamycin-sensitive (proteasome activity; phosphorylation of S6K1 and rpS6) and rapamycin-insensitive (phosphorylation of eEF2, ERK1/2 and UBF; gene expression of the myostatin target Mighty as well as c-Myc and its targets involved in ribosome biogenesis). The role of c-Myc was tested in vitro using the inhibitor 10058-F4, which, over time, decreased basal RNA and MPS in a dose-dependent manner (correlation of RNA and MPS, r(2) = 0.98), even though it had no effect on the acute stimulation of protein synthesis. In conclusion, acute resistance exercise stimulated rapamycin-sensitive and -insensitive mechanisms that regulate translation activity and capacity.
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Affiliation(s)
- Daniel W D West
- Department of Physiology & Membrane Biology, University of California Davis, Davis, CA, USA
| | - Leslie M Baehr
- Department of Physiology & Membrane Biology, University of California Davis, Davis, CA, USA
| | - George R Marcotte
- Department of Physiology & Membrane Biology, University of California Davis, Davis, CA, USA
| | - Courtney M Chason
- Department of Neurobiology, Physiology & Behavior, University of California Davis, Davis, CA, USA
| | - Luis Tolento
- Department of Neurobiology, Physiology & Behavior, University of California Davis, Davis, CA, USA
| | - Aldrin V Gomes
- Department of Physiology & Membrane Biology, University of California Davis, Davis, CA, USA.,Department of Neurobiology, Physiology & Behavior, University of California Davis, Davis, CA, USA
| | - Sue C Bodine
- Department of Physiology & Membrane Biology, University of California Davis, Davis, CA, USA.,Department of Neurobiology, Physiology & Behavior, University of California Davis, Davis, CA, USA.,VA Northern California Health Care System, Mather, CA, USA
| | - Keith Baar
- Department of Physiology & Membrane Biology, University of California Davis, Davis, CA, USA.,Department of Neurobiology, Physiology & Behavior, University of California Davis, Davis, CA, USA.,VA Northern California Health Care System, Mather, CA, USA
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Pereira MG, Silva MT, da Cunha FM, Moriscot AS, Aoki MS, Miyabara EH. Leucine supplementation improves regeneration of skeletal muscles from old rats. Exp Gerontol 2015; 72:269-77. [DOI: 10.1016/j.exger.2015.10.006] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2015] [Revised: 10/06/2015] [Accepted: 10/15/2015] [Indexed: 12/11/2022]
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Effects of ageing on expression of the muscle-specific E3 ubiquitin ligases and Akt-dependent regulation of Foxo transcription factors in skeletal muscle. Mol Cell Biochem 2015; 412:59-72. [PMID: 26590085 DOI: 10.1007/s11010-015-2608-7] [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] [Received: 09/11/2015] [Accepted: 11/14/2015] [Indexed: 12/11/2022]
Abstract
Controversy exists as to whether the muscle-specific E3 ubiquitin ligases MAFbx and MuRF1 are transcriptionally upregulated in the process of sarcopenia. In the present study, we investigated the effects of ageing on mRNA/protein expression of muscle-specific E3 ubiquitin ligases and Akt/Foxo signalling in gastrocnemius muscles of female mice. Old mice exhibited a typical sarcopenic phenotype, characterized by loss of muscle mass and strength, decreased amount of myofibrillar proteins, incidence of aberrant muscle fibres, and genetic signature to sarcopenia. Activation levels of Akt were lower in adult and old mice than in young mice. Consequently, Akt-mediated phosphorylation levels of Foxo1 and Foxo3 proteins were decreased. Nuclear levels of Foxo1 and Foxo3 proteins showed an overall increasing trend in old mice. MAFbx mRNA expression was decreased in old mice relative to adult mice, whereas MuRF1 mRNA expression was less affected by ageing. At the protein level, MAFbx was less affected by ageing, whereas MuRF1 was increased in old mice relative to adult mice, with ubiquitin-protein conjugates being increased with ageing. In conclusion, we provided evidence for no mRNA upregulation of muscle-specific E3 ubiquitin ligases and disconnection between their expression and Akt/Foxo signalling in sarcopenic mice. Their different responsiveness to ageing may reflect different roles in sarcopenia.
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West DWD, Lee-Barthel A, McIntyre T, Shamim B, Lee CA, Baar K. The exercise-induced biochemical milieu enhances collagen content and tensile strength of engineered ligaments. J Physiol 2015; 593:4665-75. [PMID: 26282066 DOI: 10.1113/jp270737] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Accepted: 08/10/2015] [Indexed: 01/27/2023] Open
Abstract
Exercise stimulates a dramatic change in the concentration of circulating hormones, such as growth hormone (GH), but the biological functions of this response are unclear. Pharmacological GH administration stimulates collagen synthesis; however, whether the post-exercise systemic milieu has a similar action is unknown. We aimed to determine whether the collagen content and tensile strength of tissue-engineered ligaments is enhanced by serum obtained post-exercise. Primary cells from a human anterior cruciate ligament (ACL) were used to engineer ligament constructs in vitro. Blood obtained from 12 healthy young men 15 min after resistance exercise contained GH concentrations that were ∼7-fold greater than resting serum (P < 0.001), whereas IGF-1 was not elevated at this time point (P = 0.21 vs. rest). Ligament constructs were treated for 7 days with medium supplemented with serum obtained at rest (RestTx) or 15 min post-exercise (ExTx), before tensile testing and collagen content analysis. Compared with RestTx, ExTx enhanced collagen content (+19%; 181 ± 33 vs. 215 ± 40 μg per construct P = 0.001) and ligament mechanical properties - maximal tensile load (+17%, P = 0.03 vs. RestTx) and ultimate tensile strength (+10%, P = 0.15 vs. RestTx). In a separate set of engineered ligaments, recombinant IGF-1, but not GH, enhanced collagen content and mechanics. Bioassays in 2D culture revealed that acute treatment with post-exercise serum activated mTORC1 and ERK1/2. In conclusion, the post-exercise biochemical milieu, but not recombinant GH, enhances collagen content and tensile strength of engineered ligaments, in association with mTORC1 and ERK1/2 activation.
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Affiliation(s)
- Daniel W D West
- Department of Physiology and Membrane Biology, University of California Davis, One Shields Ave, Davis, CA, 95616, USA
| | - Ann Lee-Barthel
- Department of Biomedical Engineering, University of California Davis, One Shields Ave, Davis, CA, 95616, USA
| | - Todd McIntyre
- Department of Biomedical Engineering, University of California Davis, One Shields Ave, Davis, CA, 95616, USA
| | - Baubak Shamim
- Department of Neurobiology, Physiology and Behaviour, University of California Davis, One Shields Ave, Davis, CA, 95616, USA
| | - Cassandra A Lee
- Department of Orthopaedic Surgery, University of California Davis, One Shields Ave, Davis, CA, 95616, USA
| | - Keith Baar
- Department of Physiology and Membrane Biology, University of California Davis, One Shields Ave, Davis, CA, 95616, USA.,Department of Biomedical Engineering, University of California Davis, One Shields Ave, Davis, CA, 95616, USA.,Department of Neurobiology, Physiology and Behaviour, University of California Davis, One Shields Ave, Davis, CA, 95616, USA
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Fortes MAS, Pinheiro CHJ, Guimarães-Ferreira L, Vitzel KF, Vasconcelos DAA, Curi R. Overload-induced skeletal muscle hypertrophy is not impaired in STZ-diabetic rats. Physiol Rep 2015. [PMID: 26197932 PMCID: PMC4552534 DOI: 10.14814/phy2.12457] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The aim of this study was to evaluate the effect of overload-induced hypertrophy on extensor digitorum longus (EDL) and soleus muscles of streptozotocin-induced diabetic rats. The overload-induced hypertrophy and absolute tetanic and twitch forces increases in EDL and soleus muscles were not different between diabetic and control rats. Phospho-Akt and rpS6 contents were increased in EDL muscle after 7 days of overload and returned to the pre-overload values after 30 days. In the soleus muscle, the contents of total and phospho-Akt and total rpS6 were increased in both groups after 7 days. The contents of total Akt in controls and total rpS6 and phospho-Akt in the diabetic rats remained increased after 30 days. mRNA expression after 7 days of overload in the EDL muscle of control and diabetic animals showed an increase in MGF and follistatin and a decrease in myostatin and Axin2. The expression of FAK was increased and of MuRF-1 and atrogin-1 decreased only in the control group, whereas Ankrd2 expression was enhanced only in diabetic rats. In the soleus muscle caused similar changes in both groups: increase in FAK and MGF and decrease in Wnt7a, MuRF-1, atrogin-1, and myostatin. Differences between groups were observed only in the increased expression of follistatin in diabetic animals and decreased Ankrd2 expression in the control group. So, insulin deficiency does not impair the overload-induced hypertrophic response in soleus and EDL muscles. However, different mechanisms seem to be involved in the comparable hypertrophic responses of skeletal muscle in control and diabetic animals.
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Affiliation(s)
- Marco Aurélio S Fortes
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Carlos Hermano J Pinheiro
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Lucas Guimarães-Ferreira
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil Exercise Metabolism Research Group, Center of Physical Education and Sports, Federal University of Espírito Santo, Vitória, Brazil
| | - Kaio F Vitzel
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Diogo A A Vasconcelos
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Rui Curi
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
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