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Herskind J, Ørtenblad N, Cheng AJ, Pedersen P, Overgaard K. Piperine enhances contractile force in slow- and fast-twitch muscle. J Physiol 2024; 602:2807-2822. [PMID: 38762879 DOI: 10.1113/jp285995] [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: 12/05/2023] [Accepted: 04/30/2024] [Indexed: 05/21/2024] Open
Abstract
Piperine has been shown to bind to myosin and shift the distribution of conformational states of myosin molecules from the super-relaxed state to the disordered relaxed state. However, little is known about the implications for muscle force production and potential underlying mechanisms. Muscle contractility experiments were performed using isolated muscles and single fibres from rats and mice. The dose-response effect of piperine on muscle force was assessed at several stimulation frequencies. The potentiation of muscle force was also tested in muscles fatigued by eccentric contractions. Potential mechanisms of force potentiation were assessed by measuring Ca2+ levels during stimulation in enzymatically dissociated muscle fibres, while myofibrillar Ca2+ sensitivity was assessed in chemically skinned muscle fibres. Piperine caused a dose-dependent increase in low-frequency force with no effect on high-frequency force in both slow- and fast-twitch muscle, with similar relative increases in twitch force, rate of force development and relaxation rate. The potentiating effect of piperine on low-frequency force was reversible, and piperine partially recovered low-frequency force in fatigued muscle. Piperine had no effect on myoplasmic free [Ca2+] levels in mouse muscle fibres, whereas piperine substantially augmented the force response to submaximal levels of [Ca2+] in rat MyHCII fibres and MyHCI fibres along with a minor increase in maximum Ca2+-activated force. Piperine enhances low-frequency force production in both fast- and slow-twitch muscle. The effects are reversible and can counteract muscle fatigue. The primary underlying mechanism appears to be an increase in Ca2+ sensitivity. KEY POINTS: Piperine is a plant alkaloid derived from black pepper. It is known to bind to skeletal muscle myosin and enhance resting ATP turnover but its effects on contractility are not well known. We showed for the first time a piperine-induced force potentiation that was pronounced during low-frequency electrical stimulation of isolated muscles. The effect of piperine was observed in both slow and fast muscle types, was reversible, and could counteract the force decrements observed after fatiguing muscle contractions. Piperine treatment caused an increase in myofibrillar Ca2+ sensitivity in chemically skinned muscle fibres, while we observed no effect on intracellular Ca2+ concentrations during electrical stimulation in enzymatically dissociated muscle fibres.
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Affiliation(s)
- Jon Herskind
- Exercise Biology, Department of Public Health, Aarhus University, Aarhus, Denmark
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Niels Ørtenblad
- Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark
| | - Arthur J Cheng
- Muscle Health Research Centre, School of Kinesiology and Health Science, Faculty of Health, York University, Toronto, Ontario, Canada
| | - Peter Pedersen
- Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark
| | - Kristian Overgaard
- Exercise Biology, Department of Public Health, Aarhus University, Aarhus, Denmark
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Elkrief D, Matusovsky O, Cheng YS, Rassier DE. From amino-acid to disease: the effects of oxidation on actin-myosin interactions in muscle. J Muscle Res Cell Motil 2023; 44:225-254. [PMID: 37805961 DOI: 10.1007/s10974-023-09658-0] [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: 06/07/2023] [Accepted: 08/15/2023] [Indexed: 10/10/2023]
Abstract
Actin-myosin interactions form the basis of the force-producing contraction cycle within the sarcomere, serving as the primary mechanism for muscle contraction. Post-translational modifications, such as oxidation, have a considerable impact on the mechanics of these interactions. Considering their widespread occurrence, the explicit contributions of these modifications to muscle function remain an active field of research. In this review, we aim to provide a comprehensive overview of the basic mechanics of the actin-myosin complex and elucidate the extent to which oxidation influences the contractile cycle and various mechanical characteristics of this complex at the single-molecule, myofibrillar and whole-muscle levels. We place particular focus on amino acids shown to be vulnerable to oxidation in actin, myosin, and some of their binding partners. Additionally, we highlight the differences between in vitro environments, where oxidation is controlled and limited to actin and myosin and myofibrillar or whole muscle environments, to foster a better understanding of oxidative modification in muscle. Thus, this review seeks to encompass a broad range of studies, aiming to lay out the multi layered effects of oxidation in in vitro and in vivo environments, with brief mention of clinical muscular disorders associated with oxidative stress.
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Affiliation(s)
- Daren Elkrief
- Department of Physiology, McGill University, Montreal, QC, Canada
| | - Oleg Matusovsky
- Department of Kinesiology and Physical Education, McGill University, Montreal, QC, Canada
| | - Yu-Shu Cheng
- Department of Kinesiology and Physical Education, McGill University, Montreal, QC, Canada
| | - Dilson E Rassier
- Department of Physiology, McGill University, Montreal, QC, Canada.
- Department of Kinesiology and Physical Education, McGill University, Montreal, QC, Canada.
- Simon Fraser University, Burnaby, BC, Canada.
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3
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Pinto AJ, Bergouignan A, Dempsey PC, Roschel H, Owen N, Gualano B, Dunstan DW. Physiology of sedentary behavior. Physiol Rev 2023; 103:2561-2622. [PMID: 37326297 PMCID: PMC10625842 DOI: 10.1152/physrev.00022.2022] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Revised: 05/10/2023] [Accepted: 06/14/2023] [Indexed: 06/17/2023] Open
Abstract
Sedentary behaviors (SB) are characterized by low energy expenditure while in a sitting or reclining posture. Evidence relevant to understanding the physiology of SB can be derived from studies employing several experimental models: bed rest, immobilization, reduced step count, and reducing/interrupting prolonged SB. We examine the relevant physiological evidence relating to body weight and energy balance, intermediary metabolism, cardiovascular and respiratory systems, the musculoskeletal system, the central nervous system, and immunity and inflammatory responses. Excessive and prolonged SB can lead to insulin resistance, vascular dysfunction, shift in substrate use toward carbohydrate oxidation, shift in muscle fiber from oxidative to glycolytic type, reduced cardiorespiratory fitness, loss of muscle mass and strength and bone mass, and increased total body fat mass and visceral fat depot, blood lipid concentrations, and inflammation. Despite marked differences across individual studies, longer term interventions aimed at reducing/interrupting SB have resulted in small, albeit marginally clinically meaningful, benefits on body weight, waist circumference, percent body fat, fasting glucose, insulin, HbA1c and HDL concentrations, systolic blood pressure, and vascular function in adults and older adults. There is more limited evidence for other health-related outcomes and physiological systems and for children and adolescents. Future research should focus on the investigation of molecular and cellular mechanisms underpinning adaptations to increasing and reducing/interrupting SB and the necessary changes in SB and physical activity to impact physiological systems and overall health in diverse population groups.
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Affiliation(s)
- Ana J Pinto
- Division of Endocrinology, Metabolism, and Diabetes, Anschutz Health and Wellness Center, University of Colorado Anschutz Medical Campus, Aurora, Colorado, United States
- Applied Physiology & Nutrition Research Group, Center of Lifestyle Medicine, Faculdade de Medicina FMUSP, Universidade de Sao Paulo, Sao Paulo, Brazil
| | - Audrey Bergouignan
- Division of Endocrinology, Metabolism, and Diabetes, Anschutz Health and Wellness Center, University of Colorado Anschutz Medical Campus, Aurora, Colorado, United States
- Institut Pluridisciplinaire Hubert Curien, Centre National de la Recherche Scientifique, Université de Strasbourg, Strasbourg, France
| | - Paddy C Dempsey
- Baker Heart & Diabetes Institute, Melbourne, Victoria, Australia
- Institute for Physical Activity and Nutrition (IPAN), School of Exercise and Nutrition Sciences, Deakin University, Geelong, Victoria, Australia
- MRC Epidemiology Unit, Institute of Metabolic Science, University of Cambridge, Cambridge Biomedical Campus, Cambridge, United Kingdom
- Diabetes Research Centre, College of Life Sciences, University of Leicester, Leicester, United Kingdom
| | - Hamilton Roschel
- Applied Physiology & Nutrition Research Group, Center of Lifestyle Medicine, Faculdade de Medicina FMUSP, Universidade de Sao Paulo, Sao Paulo, Brazil
| | - Neville Owen
- Baker Heart & Diabetes Institute, Melbourne, Victoria, Australia
- Centre for Urban Transitions, Swinburne University of Technology, Melbourne, Victoria, Australia
| | - Bruno Gualano
- Applied Physiology & Nutrition Research Group, Center of Lifestyle Medicine, Faculdade de Medicina FMUSP, Universidade de Sao Paulo, Sao Paulo, Brazil
- Food Research Center, University of Sao Paulo, Sao Paulo, Brazil
| | - David W Dunstan
- Baker Heart & Diabetes Institute, Melbourne, Victoria, Australia
- Institute for Physical Activity and Nutrition (IPAN), School of Exercise and Nutrition Sciences, Deakin University, Geelong, Victoria, Australia
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Lim JY, Frontera WR. Skeletal muscle aging and sarcopenia: Perspectives from mechanical studies of single permeabilized muscle fibers. J Biomech 2023; 152:111559. [PMID: 37027961 PMCID: PMC10164716 DOI: 10.1016/j.jbiomech.2023.111559] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Accepted: 03/21/2023] [Indexed: 03/29/2023]
Abstract
The decline in muscle mass and strength with age is well documented and associated with weakness, decreased flexibility, vulnerability to diseases and/or injuries, and impaired functional restoration. The term sarcopenia has been used to refer to the loss of muscle mass, strength and impaired physical performance with advanced adult age and recently has become a major clinical entity in a super-aged society. To understand the pathophysiology and clinical manifestations of sarcopenia, it is essential to explore the age-related changes in the intrinsic properties of muscle fibers. Mechanical experiments with single muscle fibers have been conducted during the last 80 years and applied to human muscle research in the last 45 years as an in-vitro muscle function test. Fundamental active and passive mechanical properties of skeletal muscle can be evaluated using the isolated permeabilized (chemically skinned) single muscle fiber preparation. Changes in the intrinsic properties of older human single muscle fibers can be useful biomarkers of aging and sarcopenia. In this review, we summarize the historical development of single muscle fiber mechanical studies, the definition and diagnosis of muscle aging and sarcopenia, and age-related change of active and passive mechanical properties in single muscle fibers and discuss how these changes can be used to assess muscle aging and sarcopenia.
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Affiliation(s)
- Jae-Young Lim
- Department of Rehabilitation Medicine, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam-si Gyeonggi-do, South Korea
| | - Walter R Frontera
- Department of Physiology and Department of Physical Medicine, Rehabilitation, and Sports Medicine, University of Puerto Rico School of Medicine, San Juan, Puerto Rico.
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Use of a novel technique to assess impact of age-related denervation on mouse soleus muscle function. Biogerontology 2023; 24:377-390. [PMID: 36790689 PMCID: PMC10147802 DOI: 10.1007/s10522-023-10021-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Accepted: 01/26/2023] [Indexed: 02/16/2023]
Abstract
Denervation contributes to loss of force-generating capacity in aged skeletal muscles, but problems with quantification of denervated fibers mean the precise impact of denervation on muscle function remains unclear. This study therefore looked to develop a reliable assay for identifying denervated muscle fibers, and used this to explore the impact of denervation on age-related force-generation in mouse skeletal muscle. Thirteen young (6-month-old) and 10 old (24-months-old) C57Bl/6 J female mice were utilized. Anaesthetized mice were infused with the fluorescent deoxyglucose analog 2[N-(7-nitrobenz-2-oxa-1,2-diaxol-4-yl)amino]-2-deoxyglucose (2-NBDG) and the tibial nerve was repeatedly stimulated to label active skeletal muscle fibers by activity-dependent uptake of 2-NBDG. Data on muscle force generation were acquired as part of the stimulation routine. Labeled muscles were removed, snap frozen, sectioned, and slide mounted. Sections were imaged to show accumulation of 2-NBDG in activated fibers and lack of 2-NBDG accumulation in quiescent (denervated) fibers, then processed using immunohistochemistry to allow collection of data on fiber number and morphology. Soleus muscles from older mice had nine times as many denervated fibers as those from young mice (average n = 36 vs 4, old vs young). Older muscles developed significantly more passive force and less specific force, but denervation only partly accounted for age-related deficits in specific force. Further investigations are required to definitively identify contributors to the decrease in force generation that remain unaccounted for.
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Mayfield DL, Cronin NJ, Lichtwark GA. Understanding altered contractile properties in advanced age: insights from a systematic muscle modelling approach. Biomech Model Mechanobiol 2023; 22:309-337. [PMID: 36335506 PMCID: PMC9958200 DOI: 10.1007/s10237-022-01651-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Accepted: 10/14/2022] [Indexed: 11/09/2022]
Abstract
Age-related alterations of skeletal muscle are numerous and present inconsistently, and the effect of their interaction on contractile performance can be nonintuitive. Hill-type muscle models predict muscle force according to well-characterised contractile phenomena. Coupled with simple, yet reasonably realistic activation dynamics, such models consist of parameters that are meaningfully linked to fundamental aspects of muscle excitation and contraction. We aimed to illustrate the utility of a muscle model for elucidating relevant mechanisms and predicting changes in output by simulating the individual and combined effects on isometric force of several known ageing-related adaptations. Simulating literature-informed reductions in free Ca2+ concentration and Ca2+ sensitivity generated predictions at odds qualitatively with the characteristic slowing of contraction speed. Conversely, incorporating slower Ca2+ removal or a fractional increase in type I fibre area emulated expected changes; the former was required to simulate slowing of the twitch measured experimentally. Slower Ca2+ removal more than compensated for force loss arising from a large reduction in Ca2+ sensitivity or moderate reduction in Ca2+ release, producing realistic age-related shifts in the force-frequency relationship. Consistent with empirical data, reductions in free Ca2+ concentration and Ca2+ sensitivity reduced maximum tetanic force only slightly, even when acting in concert, suggesting a modest contribution to lower specific force. Lower tendon stiffness and slower intrinsic shortening speed slowed and prolonged force development in a compliance-dependent manner without affecting force decay. This work demonstrates the advantages of muscle modelling for exploring sources of variation and identifying mechanisms underpinning the altered contractile properties of aged muscle.
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Affiliation(s)
- Dean L Mayfield
- Department of Evolution, Ecology, and Organismal Biology, University of California, Riverside, Riverside, USA.
| | - Neil J Cronin
- Neuromuscular Research Centre, Faculty of Sport and Health Sciences, University of Jyväskylä, Jyväskylä, Finland
- School of Sport and Exercise, University of Gloucestershire, Cheltenham, UK
| | - Glen A Lichtwark
- School of Human Movement and Nutrition Sciences, University of Queensland, Brisbane, Australia
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Grosicki GJ, Zepeda CS, Sundberg CW. Single muscle fibre contractile function with ageing. J Physiol 2022; 600:5005-5026. [PMID: 36268622 PMCID: PMC9722590 DOI: 10.1113/jp282298] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Accepted: 10/07/2022] [Indexed: 01/05/2023] Open
Abstract
Ageing is accompanied by decrements in the size and function of skeletal muscle that compromise independence and quality of life in older adults. Developing therapeutic strategies to ameliorate these changes is critical but requires an in-depth mechanistic understanding of the underlying physiology. Over the past 25 years, studies on the contractile mechanics of isolated human muscle fibres have been instrumental in facilitating our understanding of the cellular mechanisms contributing to age-related skeletal muscle dysfunction. The purpose of this review is to characterize the changes that occur in single muscle fibre size and contractile function with ageing and identify key areas for future research. Surprisingly, most studies observe that the size and contractile function of fibres expressing slow myosin heavy chain (MHC) I are well-preserved with ageing. In contrast, there are profound age-related decrements in the size and contractile function of the fibres expressing the MHC II isoforms. Notably, lifelong aerobic exercise training is unable to prevent most of the decrements in fast fibre contractile function, which have been implicated as a primary mechanism for the age-related loss in whole-muscle power output. These findings reveal a critical need to investigate the effectiveness of other nutritional, pharmaceutical or exercise strategies, such as lifelong resistance training, to preserve fast fibre size and function with ageing. Moreover, integrating single fibre contractile mechanics with the molecular profile and other parameters important to contractile function (e.g. phosphorylation of regulatory proteins, innervation status, mitochondrial function, fibre economy) is necessary to comprehensively understand the ageing skeletal muscle phenotype.
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Affiliation(s)
- Gregory J. Grosicki
- Biodynamics and Human Performance Center, Georgia Southern University (Armstrong Campus), Savannah, Georgia, USA
| | - Carlos S. Zepeda
- Exercise and Rehabilitation Sciences Graduate Program, Department of Physical Therapy, Marquette University, Milwaukee, Wisconsin, USA
| | - Christopher W. Sundberg
- Exercise and Rehabilitation Sciences Graduate Program, Department of Physical Therapy, Marquette University, Milwaukee, Wisconsin, USA
- Athletic and Human Performance Research Center, Marquette University, Milwaukee, Wisconsin, USA
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8
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Toth MJ, Savage PD, Voigt TB, Anair BM, Bunn JY, Smith IB, Tourville TW, Blankstein M, Stevens-Lapsley J, Nelms NJ. Effects of total knee arthroplasty on skeletal muscle structure and function at the cellular, organellar, and molecular levels. J Appl Physiol (1985) 2022; 133:647-660. [PMID: 35900327 PMCID: PMC9467475 DOI: 10.1152/japplphysiol.00323.2022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Revised: 07/11/2022] [Accepted: 07/20/2022] [Indexed: 11/22/2022] Open
Abstract
Total knee arthroplasty (TKA) is an important treatment option for knee osteoarthritis (OA) that improves self-reported pain and physical function, but objectively measured physical function typically remains reduced for years after surgery due, in part, to precipitous reductions in lower extremity neuromuscular function early after surgery. The present study examined intrinsic skeletal muscle adaptations during the first 5 weeks post-TKA to identify skeletal muscle attributes that may contribute to functional disability. Patients with advanced stage knee OA were evaluated prior to TKA and 5 weeks after surgery. Biopsies of the vastus lateralis were performed to assess muscle fiber size, contractility, and mitochondrial content, along with assessments of whole muscle size and function. TKA was accompanied by marked reductions in whole muscle size and strength. At the fiber (i.e., cellular) level, TKA caused profound muscle atrophy that was approximately twofold higher than that observed at the whole muscle level. TKA markedly reduced muscle fiber force production, contractile velocity, and power production, with force deficits persisting in myosin heavy chain (MHC) II fibers after expression relative to fiber size. Molecular level assessments suggest reduced strongly bound myosin-actin cross bridges and myofilament lattice stiffness as a mechanism underlying reduced force per unit fiber size. Finally, marked reductions in mitochondrial content were apparent and more prominent in the subsarcolemmal compartment. Our study represents the most comprehensive evaluation of skeletal muscle cellular adaptations to TKA and uncovers novel effects of TKA on muscle fiber size and intrinsic contractility early after surgery that may contribute to functional disability.NEW & NOTEWORTHY We report the first evaluation of the effects of total knee arthroplasty (TKA) on skeletal muscle at the cellular and subcellular levels. We found marked effects of TKA to cause skeletal muscle fiber atrophy and contractile dysfunction in older adults, as well as molecular mechanisms underlying impaired contractility. Our results reveal profound effects of TKA on muscle fiber size and intrinsic contractility early after surgery that may contribute to functional disability.
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Affiliation(s)
- Michael J Toth
- Department of Medicine, College of Medicine, University of Vermont, Burlington, Vermont
- Department of Orthopedics and Rehabilitation, College of Medicine, University of Vermont, Burlington, Vermont
| | - Patrick D Savage
- Department of Medicine, College of Medicine, University of Vermont, Burlington, Vermont
| | - Thomas B Voigt
- Department of Medicine, College of Medicine, University of Vermont, Burlington, Vermont
| | - Bradley M Anair
- Department of Medicine, College of Medicine, University of Vermont, Burlington, Vermont
| | - Janice Y Bunn
- Department of Medical Biostatistics, College of Engineering and Mathematical Sciences, University of Vermont, Burlington, Vermont
- Department of Mathematics and Statistics, College of Engineering and Mathematical Sciences, University of Vermont, Burlington, Vermont
| | - Isaac B Smith
- Department of Medicine, College of Medicine, University of Vermont, Burlington, Vermont
| | - Timothy W Tourville
- Department of Orthopedics and Rehabilitation, College of Medicine, University of Vermont, Burlington, Vermont
- Department of Rehabilitation and Movement Science, College of Nursing and Health Sciences, University of Vermont, Burlington, Vermont
| | - Michael Blankstein
- Department of Orthopedics and Rehabilitation, College of Medicine, University of Vermont, Burlington, Vermont
| | - Jennifer Stevens-Lapsley
- Department of Physical Medicine and Rehabilitation, University of Colorado Anschutz Medical Campus, Aurora, Colorado
- VA Eastern Colorado Geriatric Research Education and Clinical Center, Aurora, Colorado
| | - Nathaniel J Nelms
- Department of Orthopedics and Rehabilitation, College of Medicine, University of Vermont, Burlington, Vermont
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9
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Single skeletal muscle fiber mechanical properties: a muscle quality biomarker of human aging. Eur J Appl Physiol 2022; 122:1383-1395. [DOI: 10.1007/s00421-022-04924-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Accepted: 02/23/2022] [Indexed: 12/25/2022]
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10
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Effects of age on muscle power, postural control and functional capacity after short-term immobilization and retraining. JOURNAL OF MUSCULOSKELETAL & NEURONAL INTERACTIONS 2022; 22:486-497. [PMID: 36458386 PMCID: PMC9716293] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
OBJECTIVES This study investigated the effect of lower limb immobilization and retraining on postural control and muscle power in healthy old and young men. METHODS Twenty men, nine old (OM:67.3±4.4 years) and eleven young (YM:24.4±1.6 years) underwent 2 weeks of unilateral whole-leg casting, followed by 4 weeks of retraining. Measures included center of pressure (CoP) sway length and area during single- and double-leg stance, maximal leg extensor muscle power, habitual and maximal 10-m gait speed, sit-to-stand performance, and 2-min step test. RESULTS After immobilization, leg extension muscle power decreased by 15% in OM (from 2.68±0.60 to 2.29±0.63 W/kg, p<0.05) and 17% in YM (4.37±0.76 to 3.63±0.69 W/kg, p<0.05). Double-leg CoP sway area increased by 45% in OM (218±82 to 317±145 mm2; p<0.05), with no change in YM (p=0.43). Physical function did not change after immobilization but sit-to-stand performance (+20%, p<0.05) and 2-min step test (+28%, p<0.05) increased in OM following retraining. In both groups, all parameters returned to baseline levels after retraining. CONCLUSION Two weeks of lower limb immobilization led to decreases in maximal muscle power in both young and old, whereas postural control was impaired selectively in old men. All parameters were restored in both groups after 4 weeks of resistance-based retraining.
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11
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Kalakoutis M, Di Giulio I, Douiri A, Ochala J, Harridge SDR, Woledge RC. Methodological considerations in measuring specific force in human single skinned muscle fibres. Acta Physiol (Oxf) 2021; 233:e13719. [PMID: 34286921 DOI: 10.1111/apha.13719] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 07/14/2021] [Accepted: 07/15/2021] [Indexed: 02/02/2023]
Abstract
Chemically skinned fibres allow the study of human muscle contractile function in vitro. A particularly important parameter is specific force (SF), that is, maximal isometric force divided by cross-sectional area, representing contractile quality. Although SF varies substantially between studies, the magnitude and cause of this variability remains puzzling. Here, we aimed to summarize and explore the cause of variability in SF between studies. A systematic search was conducted in Medline, Embase and Web of Science databases in June 2020, yielding 137 data sets from 61 publications which studied healthy, young adults. Five-fold differences in mean SF data were observed. Adjustments to the reported data for key methodological differences allowed between-study comparisons to be made. However, adjustment for fibre shape, swelling and sarcomere length failed to significantly reduce SF variance (I2 = 96%). Interestingly, grouping papers based on shared authorship did reveal consistency within research groups. In addition, lower SF was found to be associated with higher phosphocreatine concentrations in the fibre activating solution and with Triton X-100 being used as a skinning agent. Although the analysis showed variance across the literature, the ratio of SF in single fibres containing myosin heavy chain isoforms IIA or I was found to be consistent across research groups. In conclusion, whilst the skinned fibre technique is reliable for studying in vitro force generation of single fibres, the composition of the solution used to activate fibres, which differs between research groups, is likely to heavily influence SF values.
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Affiliation(s)
- Michaeljohn Kalakoutis
- Centre for Human and Applied Physiological Sciences Faculty of Life Sciences & Medicine King’s College London London UK
| | - Irene Di Giulio
- Centre for Human and Applied Physiological Sciences Faculty of Life Sciences & Medicine King’s College London London UK
| | - Abdel Douiri
- School of Population Health and Environmental Sciences King’s College London London UK
| | - Julien Ochala
- Centre for Human and Applied Physiological Sciences Faculty of Life Sciences & Medicine King’s College London London UK
- Department of Biomedical Sciences Faculty of Health and Medical Sciences University of Copenhagen Copenhagen Denmark
| | - Stephen D. R. Harridge
- Centre for Human and Applied Physiological Sciences Faculty of Life Sciences & Medicine King’s College London London UK
| | - Roger C. Woledge
- Centre for Human and Applied Physiological Sciences Faculty of Life Sciences & Medicine King’s College London London UK
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Palke L, Schneider S, Karich B, Mende M, Josten C, Böhme J, Henkelmann R. Anti-gravity treadmill rehabilitation improves gait and muscle atrophy in patients with surgically treated ankle and tibial plateau fractures after one year: A randomised clinical trial. Clin Rehabil 2021; 36:87-98. [PMID: 34355605 DOI: 10.1177/02692155211037148] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
OBJECTIVE To compare the one-year postoperative outcomes of anti-gravity treadmill rehabilitation with those of standard rehabilitation in patients with ankle or tibial plateau fractures. DESIGN An open-label prospective randomised study. SETTING Three trauma centres. SUBJECTS Patients were randomised into the intervention (anti-gravity treadmill) or control (standard protocol) rehabilitation group. MAIN MEASURES The primary endpoint was changes in the Foot and Ankle Outcome Score for ankle fractures and Knee Injury and Osteoarthritis Outcome Score for tibial plateau fractures from baseline to 12 months after operation. Secondary endpoints were the subscores of these scores, muscle atrophy (leg circumference at 20 cm above and 10 cm below the knee joint) and the Dynamic Gait Index. RESULTS Initially, 73 patients (37 vs 36) underwent randomisation. After 12 months, 29 patients in the intervention group and 24 patients in the control group could be analysed. No significant difference was noted in the Foot and Ankle Outcome Score (80.8 ± 18.4 and 78.4 ± 21.1) and Knee Injury and Osteoarthritis Outcome Score (84.8 ± 15.2 and 81.7 ± 17.0). The change in the Dynamic Gait Index from 12 weeks to 12 months differed significantly between the groups (P = 0.04). Patients with tibial plateau fractures had a 3 cm wider thigh circumference in the intervention group than those in the control group (95% confidence interval: -0.2 to 6.3 cm, P = 0.08). CONCLUSION One year after surgery, patients who had undergone anti-gravity treadmill rehabilitation showed better gait than patients in the control group, and those with tibial plateau fractures had less muscle atrophy.
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Affiliation(s)
- Lisa Palke
- Department of Orthopedics, Trauma and Plastic Surgery, University of Leipzig, Leipzig, Germany
| | - Sebastian Schneider
- Hospital St. Georg GmbH, Clinic of Trauma, Orthopaedic and Septic Surgery, Leipzig, Germany; Ambulantes Reha Centrum Leipzig GmbH, Leipzig, Germany
| | - Bernhard Karich
- Department of Trauma and Physical Medicine, Heinrich-Braun-Klinikum GmbH, Zwickau, Germany
| | - Meinhard Mende
- Centre for Clinical Trials and Institute for Medical Informatics, Statistics and Epidemiology, University of Leipzig, Leipzig, Germany
| | - Christoph Josten
- Department of Orthopedics, Trauma and Plastic Surgery, University of Leipzig, Leipzig, Germany
| | - Jörg Böhme
- Hospital St. Georg GmbH, Clinic of Trauma, Orthopaedic and Septic Surgery, Leipzig, Germany; Ambulantes Reha Centrum Leipzig GmbH, Leipzig, Germany
| | - Ralf Henkelmann
- Department of Orthopedics, Trauma and Plastic Surgery, University of Leipzig, Leipzig, Germany
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13
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Gejl KD, Hvid LG, Andersson EP, Jensen R, Holmberg HC, Ørtenblad N. Contractile Properties of MHC I and II Fibers From Highly Trained Arm and Leg Muscles of Cross-Country Skiers. Front Physiol 2021; 12:682943. [PMID: 34220547 PMCID: PMC8242206 DOI: 10.3389/fphys.2021.682943] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Accepted: 05/18/2021] [Indexed: 11/13/2022] Open
Abstract
Introduction Little is known about potential differences in contractile properties of muscle fibers of the same type in arms and legs. Accordingly, the present study was designed to compare the force-generating capacity and Ca2+ sensitivity of fibers from arm and leg muscles of highly trained cross-country skiers. Method Single muscle fibers of m. vastus lateralis and m. triceps brachii of eight highly trained cross-country skiers were analyzed with respect to maximal Ca2+-activated force, specific force and Ca2+ sensitivity. Result The maximal Ca2+-activated force was greater for myosin heavy chain (MHC) II than MHC I fibers in both the arm (+62%, P < 0.001) and leg muscle (+77%, P < 0.001), with no differences between limbs for each MHC isoform. In addition, the specific force of MHC II fibers was higher than that of MHC I fibers in both arms (+41%, P = 0.002) and legs (+95%, P < 0.001). The specific force of MHC II fibers was the same in both limbs, whereas MHC I fibers from the m. triceps brachii were, on average, 39% stronger than fibers of the same type from the m. vastus lateralis (P = 0.003). pCa50 was not different between MHC I and II fibers in neither arms nor legs, but the MHC I fibers of m. triceps brachii demonstrated higher Ca2+ sensitivity than fibers of the same type from m. vastus lateralis (P = 0.007). Conclusion Comparison of muscles in limbs equally well trained revealed that MHC I fibers in the arm muscle exhibited a higher specific force-generating capacity and greater Ca2+ sensitivity than the same type of fiber in the leg, with no such difference in the case of MHC II fibers. These distinct differences in the properties of fibers of the same type in equally well-trained muscles open new perspectives in muscle physiology.
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Affiliation(s)
- Kasper Degn Gejl
- Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark
| | - Lars G Hvid
- Department of Public Health, Exercise Biology, Aarhus University, Aarhus, Denmark
| | - Erik P Andersson
- Swedish Winter Sports Research Centre, Department of Health Sciences, Mid Sweden University, Östersund, Sweden.,School of Sport Sciences, Faculty of Health Sciences, UiT The Arctic University of Norway, Tromsö, Norway
| | - Rasmus Jensen
- Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark
| | - Hans-Christer Holmberg
- Swedish Winter Sports Research Centre, Department of Health Sciences, Mid Sweden University, Östersund, Sweden.,Department of Health Sciences, Luleå University of Technology, Luleå, Sweden.,Department of Physiology and Pharmacology, Karolinska Institute, Stockholm, Sweden
| | - Niels Ørtenblad
- Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark
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14
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Monti E, Reggiani C, Franchi MV, Toniolo L, Sandri M, Armani A, Zampieri S, Giacomello E, Sarto F, Sirago G, Murgia M, Nogara L, Marcucci L, Ciciliot S, Šimunic B, Pišot R, Narici MV. Neuromuscular junction instability and altered intracellular calcium handling as early determinants of force loss during unloading in humans. J Physiol 2021; 599:3037-3061. [PMID: 33881176 PMCID: PMC8359852 DOI: 10.1113/jp281365] [Citation(s) in RCA: 49] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Accepted: 03/30/2021] [Indexed: 01/18/2023] Open
Abstract
Key points Few days of unloading are sufficient to induce a decline of skeletal muscle mass and function; notably, contractile force is lost at a faster rate than muscle mass. The reasons behind this disproportionate loss of muscle force are still poorly understood. We provide strong evidence of two mechanisms only hypothesized until now for the rapid muscle force loss in only 10 days of bed rest. Our results show that an initial neuromuscular junction instability, accompanied by alterations in the innervation status and impairment of single fibre sarcoplasmic reticulum function contribute to the loss of contractile force in front of a preserved myofibrillar function and central activation capacity. Early onset of neuromuscular junction instability and impairment in calcium dynamics involved in excitation–contraction coupling are proposed as eligible determinants to the greater decline in muscle force than in muscle size during unloading.
Abstract Unloading induces rapid skeletal muscle atrophy and functional decline. Importantly, force is lost at a much higher rate than muscle mass. We aimed to investigate the early determinants of the disproportionate loss of force compared to that of muscle mass in response to unloading. Ten young participants underwent 10 days of bed rest (BR). At baseline (BR0) and at 10 days (BR10), quadriceps femoris (QF) volume (VOL) and isometric maximum voluntary contraction (MVC) were assessed. At BR0 and BR10 blood samples and biopsies of vastus lateralis (VL) muscle were collected. Neuromuscular junction (NMJ) stability and myofibre innervation status were assessed, together with single fibre mechanical properties and sarcoplasmic reticulum (SR) calcium handling. From BR0 to BR10, QFVOL and MVC decreased by 5.2% (P = 0.003) and 14.3% (P < 0.001), respectively. Initial and partial denervation was detected from increased neural cell adhesion molecule (NCAM)‐positive myofibres at BR10 compared with BR0 (+3.4%, P = 0.016). NMJ instability was further inferred from increased C‐terminal agrin fragment concentration in serum (+19.2% at BR10, P = 0.031). Fast fibre cross‐sectional area (CSA) showed a trend to decrease by 15% (P = 0.055) at BR10, while single fibre maximal tension (force/CSA) was unchanged. However, at BR10 SR Ca2+ release in response to caffeine decreased by 35.1% (P < 0.002) and 30.2% (P < 0.001) in fast and slow fibres, respectively, pointing to an impaired excitation–contraction coupling. These findings support the view that the early onset of NMJ instability and impairment in SR function are eligible mechanisms contributing to the greater decline in muscle force than in muscle size during unloading. Few days of unloading are sufficient to induce a decline of skeletal muscle mass and function; notably, contractile force is lost at a faster rate than muscle mass. The reasons behind this disproportionate loss of muscle force are still poorly understood. We provide strong evidence of two mechanisms only hypothesized until now for the rapid muscle force loss in only 10 days of bed rest. Our results show that an initial neuromuscular junction instability, accompanied by alterations in the innervation status and impairment of single fibre sarcoplasmic reticulum function contribute to the loss of contractile force in front of a preserved myofibrillar function and central activation capacity. Early onset of neuromuscular junction instability and impairment in calcium dynamics involved in excitation–contraction coupling are proposed as eligible determinants to the greater decline in muscle force than in muscle size during unloading.
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Affiliation(s)
- Elena Monti
- Department of Biomedical Sciences, University of Padova, Padova, 35131, Italy
| | - Carlo Reggiani
- Department of Biomedical Sciences, University of Padova, Padova, 35131, Italy.,Science and Research Center Koper, Institute for Kinesiology Research, Koper, 6000, Slovenia
| | - Martino V Franchi
- Department of Biomedical Sciences, University of Padova, Padova, 35131, Italy
| | - Luana Toniolo
- Department of Biomedical Sciences, University of Padova, Padova, 35131, Italy
| | - Marco Sandri
- Department of Biomedical Sciences, University of Padova, Padova, 35131, Italy.,Department of Biomedical Sciences, Venetian Institute of Molecular Medicine, University of Padova, Via Orus 2, Padova, 35129, Italy
| | - Andrea Armani
- Department of Biomedical Sciences, University of Padova, Padova, 35131, Italy.,Department of Biomedical Sciences, Venetian Institute of Molecular Medicine, University of Padova, Via Orus 2, Padova, 35129, Italy
| | - Sandra Zampieri
- Department of Biomedical Sciences, University of Padova, Padova, 35131, Italy.,Department of Surgery, Oncology, and Gastroenterology, University of Padova, Padova, 35124, Italy
| | - Emiliana Giacomello
- Clinical Department of Medical, Surgical and Health Sciences, Strada di Fiume, 447, Trieste, 34149, Italy
| | - Fabio Sarto
- Department of Biomedical Sciences, University of Padova, Padova, 35131, Italy
| | - Giuseppe Sirago
- Department of Biomedical Sciences, University of Padova, Padova, 35131, Italy
| | - Marta Murgia
- Department of Biomedical Sciences, University of Padova, Padova, 35131, Italy.,Department of Proteomics and Signal Transduction, Max-Planck-Institute of Biochemistry Am Klopferspitz 18, Martinsried, 82152, Germany
| | - Leonardo Nogara
- Department of Biomedical Sciences, University of Padova, Padova, 35131, Italy
| | - Lorenzo Marcucci
- Department of Biomedical Sciences, University of Padova, Padova, 35131, Italy
| | - Stefano Ciciliot
- Department of Biomedical Sciences, University of Padova, Padova, 35131, Italy.,Department of Biomedical Sciences, Venetian Institute of Molecular Medicine, University of Padova, Via Orus 2, Padova, 35129, Italy
| | - Boštjan Šimunic
- Science and Research Center Koper, Institute for Kinesiology Research, Koper, 6000, Slovenia
| | - Rado Pišot
- Science and Research Center Koper, Institute for Kinesiology Research, Koper, 6000, Slovenia
| | - Marco V Narici
- Department of Biomedical Sciences, University of Padova, Padova, 35131, Italy.,Science and Research Center Koper, Institute for Kinesiology Research, Koper, 6000, Slovenia.,CIR-MYO Myology Center, University of Padova, Padova, 35131, Italy
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15
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Rate of force development is Ca 2+-dependent and influenced by Ca 2+-sensitivity in human single muscle fibres from older adults. Exp Gerontol 2021; 150:111348. [PMID: 33862138 DOI: 10.1016/j.exger.2021.111348] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 04/07/2021] [Accepted: 04/08/2021] [Indexed: 11/20/2022]
Abstract
Natural adult aging is associated with declines in skeletal muscle performance, including impaired Ca2+ sensitivity and a slowing of rapid force production (rate of force redevelopment; ktr). The purpose of this study was to investigate the relationship between impaired Ca2+ sensitivity and ktr of single muscle fibres from young and older adults. Participants included 8 young (22-35 yrs) and 8 older (60-81 yrs) males who were living independently. A percutaneous muscle biopsy of the vastus lateralis of each participant was performed. Single muscle fibre mechanical tests included maximal Ca2+-activated force (Po), force-pCa curves, and ktr. We showed a decrease in pCa50 in old type II fibres compared to young, indicating impaired Ca2+ sensitivity in older adults. The ktr behaved in a Ca2+-dependent manner such that with increasing [Ca2+], ktr increases, to a plateau. Interestingly, ktr was not different between young and old muscle fibres. Furthermore, we found strong associations between pCa50 and ktr in both old type I and type II fibres, such that those fibres with lower Ca2+ sensitivity had a slowed ktr. This Ca2+ association, combined with impaired Ca2+ handling in older adults suggests a potential Ca2+-dependent mechanism affecting the transition from weakly- to strongly-bound cross-bridge states, leading to a decline in skeletal muscle performance. Future research is needed to explore the role alterations to Ca2+ sensitivity/handling could be playing in age-related whole muscle performance declines.
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16
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Alcazar J, Aagaard P, Haddock B, Kamper RS, Hansen SK, Prescott E, Alegre LM, Frandsen U, Suetta C. Age- and Sex-Specific Changes in Lower-Limb Muscle Power Throughout the Lifespan. J Gerontol A Biol Sci Med Sci 2021; 75:1369-1378. [PMID: 31943003 DOI: 10.1093/gerona/glaa013] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Our main goal was to evaluate the pattern and time course of changes in relative muscle power and its constituting components throughout the life span. METHODS A total of 1,305 subjects (729 women and 576 men; aged 20-93 years) participating in the Copenhagen Sarcopenia Study took part. Body mass index (BMI), leg lean mass assessed by dual-energy X-ray absorptiometry (DXA), and leg extension muscle power (LEP) assessed by the Nottingham power rig were recorded. Relative muscle power (normalized to body mass) and specific muscle power (normalized to leg lean mass) were calculated. Segmented regression analyses were used to identify the onset and pattern of age-related changes in the recorded variables. RESULTS Relative muscle power began to decline above the age of 40 in both women and men, with women showing an attenuation of the decline above 75 years. Relative muscle power decreased with age due to (i) the loss of absolute LEP after the fourth decade of life and (ii) the increase in BMI up to the age of 75 years in women and 65 years in men. The decline in absolute LEP was caused by a decline in specific LEP up to the age of 75 in women and 65 in men, above which the loss in relative leg lean mass also contributed. CONCLUSIONS Relative power decreased (i) above 40 years by the loss in absolute power (specific power only) and the increase in body mass, and (ii) above ~70 years by the loss in absolute power (both specific power and leg lean mass).
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Affiliation(s)
- Julian Alcazar
- GENUD Toledo Research Group, Universidad de Castilla-La Mancha, Spain.,CIBER of Frailty and Healthy Aging (CIBERFES), Madrid, Spain.,Geriatric Research Unit, Geriatric Department, Bispebjerg University Hospital, Copenhagen, Denmark
| | - Per Aagaard
- Institute of Sports Science and Clinical Biomechanics, University of Southern Denmark. Odense
| | - Bryan Haddock
- Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet-Glostrup University Hospital, Copenhagen, Denmark
| | - Rikke S Kamper
- Geriatric Research Unit, Geriatric Department, Bispebjerg University Hospital, Copenhagen, Denmark
| | - Sofie K Hansen
- Geriatric Research Unit, Geriatric Department, Bispebjerg University Hospital, Copenhagen, Denmark
| | - Eva Prescott
- Department of Cardiology, Bispebjerg-Frederiksberg University Hospital, Copenhagen, Denmark.,Copenhagen City Heart Study, Frederiksberg University Hospital, Denmark
| | - Luis M Alegre
- GENUD Toledo Research Group, Universidad de Castilla-La Mancha, Spain.,CIBER of Frailty and Healthy Aging (CIBERFES), Madrid, Spain
| | - Ulrik Frandsen
- Institute of Sports Science and Clinical Biomechanics, University of Southern Denmark. Odense
| | - Charlotte Suetta
- Geriatric Research Unit, Geriatric Department, Bispebjerg University Hospital, Copenhagen, Denmark.,Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet-Glostrup University Hospital, Copenhagen, Denmark.,Geriatric Research Unit, Department of Internal Medicine, Herlev-Gentofte University Hospital, Copenhagen, Denmark
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17
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Howard EE, Pasiakos SM, Fussell MA, Rodriguez NR. Skeletal Muscle Disuse Atrophy and the Rehabilitative Role of Protein in Recovery from Musculoskeletal Injury. Adv Nutr 2020; 11:989-1001. [PMID: 32167129 PMCID: PMC7360452 DOI: 10.1093/advances/nmaa015] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Revised: 12/29/2019] [Accepted: 02/04/2020] [Indexed: 01/05/2023] Open
Abstract
Muscle atrophy and weakness occur as a consequence of disuse after musculoskeletal injury (MSI). The slow recovery and persistence of these deficits even after physical rehabilitation efforts indicate that interventions designed to attenuate muscle atrophy and protect muscle function are necessary to accelerate and optimize recovery from MSI. Evidence suggests that manipulating protein intake via dietary protein or free amino acid-based supplementation diminishes muscle atrophy and/or preserves muscle function in experimental models of disuse (i.e., immobilization and bed rest in healthy populations). However, this concept has rarely been considered in the context of disuse following MSI, which often occurs with some muscle activation during postinjury physical rehabilitation. Given that exercise sensitizes skeletal muscle to the anabolic effect of protein ingestion, early rehabilitation may act synergistically with dietary protein to protect muscle mass and function during postinjury disuse conditions. This narrative review explores mechanisms of skeletal muscle disuse atrophy and recent advances delineating the role of protein intake as a potential countermeasure. The possible synergistic effect of protein-based interventions and postinjury rehabilitation in attenuating muscle atrophy and weakness following MSI is also considered.
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Affiliation(s)
- Emily E Howard
- Department of Nutritional Sciences, University of Connecticut, Storrs, CT, USA,Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA, USA,Oak Ridge Institute for Science and Education, Oak Ridge, TN, USA
| | - Stefan M Pasiakos
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA, USA
| | - Maya A Fussell
- Department of Nutritional Sciences, University of Connecticut, Storrs, CT, USA
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18
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Hansen SK, Ratzer J, Nielsen JL, Suetta C, Karlsen A, Kvorning T, Frandsen U, Aagaard P. Effects of alternating blood flow restricted training and heavy-load resistance training on myofiber morphology and mechanical muscle function. J Appl Physiol (1985) 2020; 128:1523-1532. [PMID: 32324471 DOI: 10.1152/japplphysiol.00015.2020] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
To investigate if short-term block-structured training consisting of alternating weeks of blood flow restricted low-load resistance training (BFR-RT) and conventional free-flow heavy-load resistance training (HL-RT) leads to superior gains in mechanical muscle function, myofiber size, and satellite cell (SC) content and myonuclear number compared with HL-RT alone. Eighteen active young participants (women/men: 5/13, 23 ± 1.2 yr) were randomized to 6 wk (22 sessions) of lower limb HL-RT [70-90% one repetition maximum (1-RM)] (HRT, n = 9) or block-structured training alternating weekly between BFR-RT (20% 1-RM) and HL-RT (BFR-HRT, n = 9). Maximal isometric knee extensor strength (MVC) and muscle biopsies (VL) were obtained pre- and posttraining to examine changes in muscle strength, myofiber cross-sectional area (CSA), myonuclear (MN) number, and SC content. MVC increased in both training groups (BFR-HRT: +12%, HRT: +7%; P < 0.05). Type II myofiber CSA increased similarly (+16%) in BFR-HRT and HRT (P < 0.05), while gains in type I CSA were observed following HRT only (+12%, P < 0.05). In addition, myonuclear number remained unchanged, whereas SC content increased in type II myofibers following HRT (+59%, P < 0.05). Short-term alternating BFR-RT and HL-RT did not produce superior gains in muscle strength or myofiber size compared with HL-RT alone. Noticeably, however, conventional HL-RT could be periodically replaced by low-load BFR-RT without compromising training-induced gains in maximal muscle strength and type II myofiber size, respectively.NEW & NOTEWORTHY The present data demonstrate that periodically substituting heavy-load resistance training (HL-RT) with low-load blood flow restricted resistance training (BFR-RT) leads to similar gains in type II myofiber CSA and muscle strength as achieved by HL-RT alone. Furthermore, we have for the first time evaluated myonuclear content and myonuclear domain size before and after training intervention across separate fiber size clusters and found no within-cluster changes for these parameters with training.
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Affiliation(s)
- S K Hansen
- Institute of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark.,Geriatric Research Unit, Bispebjerg-Frederiksberg University Hospital, Copenhagen, Denmark
| | - J Ratzer
- Institute of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark
| | - J L Nielsen
- Institute of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark
| | - C Suetta
- Geriatric Research Unit, Bispebjerg-Frederiksberg University Hospital, Copenhagen, Denmark.,Geriatric Research Unit, Herlev-Gentofte University Hospital, Copenhagen, Denmark
| | - A Karlsen
- Institute of Sports Medicine Copenhagen, Denmark.,Department of Orthopaedic Surgery M, Bispebjerg Hospital, Copenhagen, Denmark.,Center of Healthy Aging, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - T Kvorning
- Institute of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark.,Team Danmark (The Danish Elite Sport Institution), Brøndby, Denmark
| | - U Frandsen
- Institute of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark
| | - P Aagaard
- Institute of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark
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19
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Marshall RN, Smeuninx B, Morgan PT, Breen L. Nutritional Strategies to Offset Disuse-Induced Skeletal Muscle Atrophy and Anabolic Resistance in Older Adults: From Whole-Foods to Isolated Ingredients. Nutrients 2020; 12:nu12051533. [PMID: 32466126 PMCID: PMC7284346 DOI: 10.3390/nu12051533] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 05/19/2020] [Accepted: 05/22/2020] [Indexed: 12/14/2022] Open
Abstract
Preserving skeletal muscle mass and functional capacity is essential for healthy ageing. Transient periods of disuse and/or inactivity in combination with sub-optimal dietary intake have been shown to accelerate the age-related loss of muscle mass and strength, predisposing to disability and metabolic disease. Mechanisms underlying disuse and/or inactivity-related muscle deterioration in the older adults, whilst multifaceted, ultimately manifest in an imbalance between rates of muscle protein synthesis and breakdown, resulting in net muscle loss. To date, the most potent intervention to mitigate disuse-induced muscle deterioration is mechanical loading in the form of resistance exercise. However, the feasibility of older individuals performing resistance exercise during disuse and inactivity has been questioned, particularly as illness and injury may affect adherence and safety, as well as accessibility to appropriate equipment and physical therapists. Therefore, optimising nutritional intake during disuse events, through the introduction of protein-rich whole-foods, isolated proteins and nutrient compounds with purported pro-anabolic and anti-catabolic properties could offset impairments in muscle protein turnover and, ultimately, the degree of muscle atrophy and recovery upon re-ambulation. The current review therefore aims to provide an overview of nutritional countermeasures to disuse atrophy and anabolic resistance in older individuals.
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Affiliation(s)
- Ryan N. Marshall
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK; (R.N.M.); (B.S.); (P.T.M.)
- Medical Research Council-Versus Arthritis Centre for Musculoskeletal Ageing, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
| | - Benoit Smeuninx
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK; (R.N.M.); (B.S.); (P.T.M.)
- Medical Research Council-Versus Arthritis Centre for Musculoskeletal Ageing, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC 3052, Australia
| | - Paul T. Morgan
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK; (R.N.M.); (B.S.); (P.T.M.)
- Medical Research Council-Versus Arthritis Centre for Musculoskeletal Ageing, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
| | - Leigh Breen
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK; (R.N.M.); (B.S.); (P.T.M.)
- Medical Research Council-Versus Arthritis Centre for Musculoskeletal Ageing, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
- Correspondence: ; Tel.: +44-121-414-4109
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20
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Sun X, Wang W, Dong Y, Wang Y, Zhang M, Wang Z, Yu X, Huang J, Cai H. Relationship between calcium circulation-related factors and muscle strength in rat sciatic nerve injury model. IRANIAN JOURNAL OF BASIC MEDICAL SCIENCES 2020; 23:654-662. [PMID: 32742604 PMCID: PMC7375001 DOI: 10.22038/ijbms.2020.40915.9695] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVES The purpose of this study is to investigate the indication function of the calcium circulation-related factors on the damage to muscle strength and contraction function after nerve injury. The target factors include ryanodine receptor (RyR), inositol-1,4,5-triphosphate receptor (IP3R), phospholamban (PLN), cryptocalcitonin (CASQ), ATPase and troponin C (TNNC). MATERIALS AND METHODS Sprague-Dawley (SD) rats were randomly divided into sham-operated group (SO), sciatic nerve injury group (SNI) and sciatic nerve disconnection group (SNT). Sciatic nerve function index and stretching test were used to examine the changes to muscle strength; bilateral gastrocnemius muscles were extracted after execution for gastrocnemius wet weight ratio test. HE staining slides and average cross-sectional area of muscle fibers were acquired to analyze the muscle atrophy. The transcription level of the factors was also measured. RESULTS Sciatic nerve damage in SNI group was significantly higher than that in SO group in the 6 weeks, but there was no significant difference between SNT and SO groups fallowing sciatic nerve damage. Sciatic nerve function in SNT group was worse than that in SNI group. The average cross-sectional area of gastrocnemius muscle fibers in SNI and SNT groups was significantly reduced compared to that in SO group. The transcriptional levels of RyR, PLN, CASQ, ATPase and TNNC in SNI and SNT groups were significantly different from those in SO group. CONCLUSION Calcium circulation-related factors could be used as potential indicators for assessment of damages to muscle strength.
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Affiliation(s)
- Xiaoming Sun
- Department of Forensic Medicine, Xuzhou Medical University, Xuzhou, Jiangsu, P. R. China
| | - Wei Wang
- Department of Forensic Medicine, Xuzhou Medical University, Xuzhou, Jiangsu, P. R. China
| | - Yangyi Dong
- Department of Forensic Medicine, Xuzhou Medical University, Xuzhou, Jiangsu, P. R. China
| | - Yue Wang
- Department of Forensic Medicine, Xuzhou Medical University, Xuzhou, Jiangsu, P. R. China
| | - Meixiang Zhang
- Department of Forensic Medicine, Xuzhou Medical University, Xuzhou, Jiangsu, P. R. China
| | - Zhao Wang
- Department of Forensic Medicine, Xuzhou Medical University, Xuzhou, Jiangsu, P. R. China
| | - Xiaowei Yu
- Department of Forensic Medicine, Xuzhou Medical University, Xuzhou, Jiangsu, P. R. China
| | - Jiao Huang
- Department of Forensic Medicine, Xuzhou Medical University, Xuzhou, Jiangsu, P. R. China
| | - Hongxing Cai
- Department of Forensic Medicine, Xuzhou Medical University, Xuzhou, Jiangsu, P. R. China,Corresponding author: Hongxing Cai. Department of Forensic Medicine, Xuzhou Medical University, Xuzhou, Jiangsu, P. R. China. Tel: 0516-85748442
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21
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Teigen LE, Sundberg CW, Kelly LJ, Hunter SK, Fitts RH. Ca 2+ dependency of limb muscle fiber contractile mechanics in young and older adults. Am J Physiol Cell Physiol 2020; 318:C1238-C1251. [PMID: 32348175 DOI: 10.1152/ajpcell.00575.2019] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Age-induced declines in skeletal muscle contractile function have been attributed to multiple cellular factors, including lower peak force (Po), decreased Ca2+ sensitivity, and reduced shortening velocity (Vo). However, changes in these cellular properties with aging remain unresolved, especially in older women, and the effect of submaximal Ca2+ on contractile function is unknown. Thus, we compared contractile properties of muscle fibers from 19 young (24 ± 3 yr; 8 women) and 21 older adults (77 ± 7 yr; 7 women) under maximal and submaximal Ca2+ and assessed the abundance of three proteins thought to influence Ca2+ sensitivity. Fast fiber cross-sectional area was ~44% larger in young (6,479 ± 2,487 µm2) compared with older adults (4,503 ± 2,071 µm2, P < 0.001), which corresponded with a greater absolute Po (young = 1.12 ± 0.43 mN; old = 0.79 ± 0.33 mN, P < 0.001). There were no differences in fast fiber size-specific Po, indicating the age-related decline in force was explained by differences in fiber size. Except for fast fiber size and absolute Po, no age or sex differences were observed in Ca2+ sensitivity, rate of force development (ktr), or Vo in either slow or fast fibers. Submaximal Ca2+ depressed ktr and Vo, but the effects were not altered by age in either sex. Contrary to rodent studies, regulatory light chain (RLC) and myosin binding protein-C abundance and RLC phosphorylation were unaltered by age or sex. These data suggest the age-associated reductions in contractile function are primarily due to the atrophy of fast fibers and that caution is warranted when extending results from rodent studies to humans.
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Affiliation(s)
- Laura E Teigen
- Department of Biological Sciences, Marquette University, Milwaukee, Wisconsin
| | - Christopher W Sundberg
- Department of Biological Sciences, Marquette University, Milwaukee, Wisconsin.,Department of Physical Therapy, Marquette University, Milwaukee, Wisconsin
| | - Lauren J Kelly
- Department of Biological Sciences, Marquette University, Milwaukee, Wisconsin
| | - Sandra K Hunter
- Department of Physical Therapy, Marquette University, Milwaukee, Wisconsin
| | - Robert H Fitts
- Department of Biological Sciences, Marquette University, Milwaukee, Wisconsin
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22
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Abstract
BACKGROUND Muscle strength loss following immobilisation has been predominantly attributed to rapid muscle atrophy. However, this cannot fully explain the magnitude of muscle strength loss, so changes in neuromuscular function (NMF) may be involved. OBJECTIVES We systematically reviewed literature that quantified changes in muscle strength, size and NMF following periods of limb immobilisation in vivo in humans. METHODS Studies were identified following systematic searches, assessed for inclusion, data extracted and quality appraised by two reviewers. Data were tabulated and reported narratively. RESULTS Forty eligible studies were included, 22 immobilised lower and 18 immobilised upper limbs. Limb immobilisation ranged from 12 h to 56 days. Isometric muscle strength and muscle size declined following immobilisation; however, change magnitude was greater for strength than size. Evoked resting twitch force decreased for lower but increased for upper limbs. Rate of force development either remained unchanged or slowed for lower and typically slowed for upper limbs. Twitch relaxation rate slowed for both lower and upper limbs. Central motor drive typically decreased for both locations, while electromyography amplitude during maximum voluntary contractions decreased for the lower and presented mixed findings for the upper limbs. Trends imply faster rates of NMF loss relative to size earlier in immobilisation periods for all outcomes. CONCLUSIONS Limb immobilisation results in non-uniform loss of isometric muscle strength, size and NMF over time. Different outcomes between upper and lower limbs could be attributed to higher degrees of central neural control of upper limb musculature. Future research should focus on muscle function losses and mechanisms following acute immobilisation. REGISTRATION PROSPERO reference: CRD42016033692.
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Chang H, Peng X, Yan X, Zhang J, Xu S, Wang H, Wang Z, Ma X, Gao Y. Autophagy and Akt-mTOR signaling display periodic oscillations during torpor-arousal cycles in oxidative skeletal muscle of Daurian ground squirrels (Spermophilus dauricus). J Comp Physiol B 2019; 190:113-123. [PMID: 31729534 DOI: 10.1007/s00360-019-01245-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Revised: 10/20/2019] [Accepted: 11/06/2019] [Indexed: 12/29/2022]
Abstract
Whether hibernation accelerates or suppresses autophagy is still unknown. In the current study, we examined changes in autophagy in oxidative soleus (SOL) muscle in summer active (SA), pre-hibernation (PRE), torpor (TOR), interbout arousal (IBA), and post-hibernation groups of Daurian ground squirrels (Spermophilus dauricus). Here, the SOL muscle showed no significant atrophy during hibernation in regard to muscle wet weight, fiber cross-sectional area, or MuRF1 protein level. Autophagy-related proteins beclin1 and Atg7 increased significantly, whereas LC3-II decreased significantly in the PRE group compared with the SA group. However, neither the expression nor activity of cathepsin L showed any differences between the SA and PRE groups. In addition, beclin1, LC3-II, and the LC3-II/LC3-I ratio increased, p62 decreased, LC3 puncta increased, p62 puncta decreased, and cathepsin L activity increased in the TOR group compared with the PRE group. In contrast, beclin1, LC3-II, and the LC3-II/LC3-I ratio decreased, p62 increased, LC3 puncta decreased, p62 puncta increased, and cathepsin L activity declined in the IBA group compared with the TOR group. Moreover, the phosphorylation of Akt (Ser473) and mTOR (Ser2448) changed significantly during hibernation and showed an inverse relationship with autophagy changes. In conclusion, autophagy proteins displayed periodic oscillation in the torpor-arousal cycle, which may be advantageous in maintaining SOL muscle mass during the entire hibernation period. Furthermore, the Akt-mTOR signaling was decreased in TOR and increased in IBA group in the SOL muscle of Daurian ground squirrels during hibernation.
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Affiliation(s)
- Hui Chang
- Shaanxi Key Laboratory for Animal Conservation, Northwest University, Xi'an, 710069, People's Republic of China.,Key Laboratory of Resource Biology and Biotechnology in Western China, College of Life Sciences, Northwest University, Ministry of Education, 229# North Taibai Road, Xi'an, 710069, People's Republic of China
| | - Xin Peng
- Key Laboratory of Resource Biology and Biotechnology in Western China, College of Life Sciences, Northwest University, Ministry of Education, 229# North Taibai Road, Xi'an, 710069, People's Republic of China
| | - Xia Yan
- Key Laboratory of Resource Biology and Biotechnology in Western China, College of Life Sciences, Northwest University, Ministry of Education, 229# North Taibai Road, Xi'an, 710069, People's Republic of China
| | - Jie Zhang
- Key Laboratory of Resource Biology and Biotechnology in Western China, College of Life Sciences, Northwest University, Ministry of Education, 229# North Taibai Road, Xi'an, 710069, People's Republic of China
| | - Shenhui Xu
- Key Laboratory of Resource Biology and Biotechnology in Western China, College of Life Sciences, Northwest University, Ministry of Education, 229# North Taibai Road, Xi'an, 710069, People's Republic of China
| | - Huiping Wang
- Shaanxi Key Laboratory for Animal Conservation, Northwest University, Xi'an, 710069, People's Republic of China.,Key Laboratory of Resource Biology and Biotechnology in Western China, College of Life Sciences, Northwest University, Ministry of Education, 229# North Taibai Road, Xi'an, 710069, People's Republic of China
| | - Zhe Wang
- Key Laboratory of Resource Biology and Biotechnology in Western China, College of Life Sciences, Northwest University, Ministry of Education, 229# North Taibai Road, Xi'an, 710069, People's Republic of China
| | - Xiufeng Ma
- Key Laboratory of Resource Biology and Biotechnology in Western China, College of Life Sciences, Northwest University, Ministry of Education, 229# North Taibai Road, Xi'an, 710069, People's Republic of China
| | - Yunfang Gao
- Shaanxi Key Laboratory for Animal Conservation, Northwest University, Xi'an, 710069, People's Republic of China. .,Key Laboratory of Resource Biology and Biotechnology in Western China, College of Life Sciences, Northwest University, Ministry of Education, 229# North Taibai Road, Xi'an, 710069, People's Republic of China.
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24
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Gaffley M, Weaver AA, Talton JW, Barnard RT, Stitzel JD, Zonfrillo MR. Age-based differences in the disability of extremity injuries in pediatric and adult occupants. TRAFFIC INJURY PREVENTION 2019; 20:S63-S68. [PMID: 31560215 PMCID: PMC7035195 DOI: 10.1080/15389588.2019.1658873] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Revised: 08/13/2019] [Accepted: 08/17/2019] [Indexed: 06/10/2023]
Abstract
Objective: The objective was to develop a disability-based metric for motor vehicle crash (MVC) upper and lower extremity injuries and compare functional outcomes between children and adults.Methods: Disability risk (DR) was quantified using Functional Independence Measure (FIM) scores within the National Trauma Data Bank-Research Data System for the top 95% most frequently occurring Abbreviated Injury Scale (AIS) 3 extremity injuries (22 unique injuries). Pediatric (7-18 years), young adult (19-45 years), middle-aged (46-65 years), and older adult (66+ years) MVC occupants with an FIM score and at least one of the 22 extremity injuries were included. DR was calculated for each injury as the proportion of occupants who were disabled of those sustaining the injury. A maximum AIS-adjusted disability risk (DRMAIS) was also calculated for each injury, excluding occupants with AIS 4+ co-injuries.Results: Locomotion impairment was the most frequent disability type across all ages. DR and DRMAIS of the extremity injuries ranged from 0.06 to 1.00 (6%-100% disability risk). Disability risk increased with age, with DRMAIS increasing from 25.9% ± 8.6% (mean ± SD) in pediatric subjects to 30.4% ± 6.3% in young adults, 39.5% ± 6.6% in middle-aged adults, and 60.5 ± 13.3% in older adults. DRMAIS for upper extremity fractures differed significantly between age groups, with higher disability in older adults, followed by middle-aged adults. DRMAIS for pelvis, hip, shaft, knee, and other lower extremity fractures differed significantly between age groups, with older adult DRMAIS being significantly higher for each fracture type. DRMAIS for hip and lower extremity shaft fractures was also significantly higher in middle-aged occupants compared to pediatric and young adult occupants. The maximum AIS-adjusted mortality risk (MRMAIS, proportion of fatalities among occupants sustaining an MAIS 3 injury) was not correlated with DRMAIS for extremity injuries in pediatric, young adult, middle-aged, and older adult occupants (all R2 < 0.01). Disability associated with each extremity injury was higher than mortality risk.Conclusions: Older adults had significantly greater disability for MVC extremity injuries. Lower disability rates in children may stem from their increased physiological capacity for bone healing and relative lack of bone disease. The disability metrics developed can supplement AIS and other severity-based metrics by accounting for the age-specific functional implications of MVC extremity injuries.
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Affiliation(s)
- Michaela Gaffley
- General Surgery, Wake Forest School of Medicine, Winston–Salem, North Carolina
| | - Ashley A. Weaver
- School of Biomedical Engineering and Sciences, Virginia Tech–Wake Forest University, Winston–Salem, North Carolina
| | - Jennifer W. Talton
- Wake Forest School of Medicine, Division of Public Health Sciences, Winston–Salem, North Carolina
| | - Ryan T. Barnard
- Wake Forest School of Medicine, Division of Public Health Sciences, Winston–Salem, North Carolina
| | - Joel D. Stitzel
- School of Biomedical Engineering and Sciences, Virginia Tech–Wake Forest University, Winston–Salem, North Carolina
| | - Mark R. Zonfrillo
- Department of Emergency Medicine, Alpert Medical School of Brown University and Hasbro Children’s Hospital, Providence, Rhode Island
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25
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Jeon Y, Choi J, Kim HJ, Lee H, Lim JY, Choi SJ. Sex- and fiber-type-related contractile properties in human single muscle fiber. J Exerc Rehabil 2019; 15:537-545. [PMID: 31523674 PMCID: PMC6732543 DOI: 10.12965/jer.1938336.168] [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: 06/02/2019] [Accepted: 07/09/2019] [Indexed: 11/22/2022] Open
Abstract
This study aimed to examine the distribution and contractile properties of single muscle fiber sex/myosin heavy chain (MHC) type-related differences and to evaluate the correlation of cross-sectional area (CSA) and specific force (SF) in a single muscle fiber. Six young men and six young women were participated in this study. Muscle sample was obtained from vastus lateralis muscle. To examine potential gender differences within each fiber contractile properties (CSA, maximal isometric force, SF, maximal shortening velocity) and relationship between CSA and SF of single fiber using Pearson correlation. After mechanical measurements, single muscle fiber determined MHC isoforms using silver stain. MHC isoform composition did not differ by sex (chi-square=6.978, P=0.073). There were sex-related differences in CSA and maximal isometric force (P<0.05), but no fiber type-related differences (P>0.05). Related to SF and maximal shortening velocity, there were no sex-related differences only fiber type-related differences (P<0.05). However, there were differences in SF between single fiber types in men but not in women. A negative correlation was found between CSA and SF in both men and women (P<0.05). It is suggested that there might be different mechanical properties of cross-bridges according to sex.
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Affiliation(s)
- Yunah Jeon
- Division of Sports and Health Science, Kyungsung University, Busan, Korea.,Mechanical & Molecular Myology Lab, Department of Rehabilitation Medicine, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Korea
| | - Junghwa Choi
- Division of Sports and Health Science, Kyungsung University, Busan, Korea
| | - Hee Jaeng Kim
- Division of Sports and Health Science, Kyungsung University, Busan, Korea
| | - Hojun Lee
- Division of Sports and Health Science, Kyungsung University, Busan, Korea.,Mechanical & Molecular Myology Lab, Department of Rehabilitation Medicine, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Korea
| | - Jae-Young Lim
- Mechanical & Molecular Myology Lab, Department of Rehabilitation Medicine, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Korea
| | - Seung-Jun Choi
- Division of Sports and Health Science, Kyungsung University, Busan, Korea
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26
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Friedrich O, Haug M, Reischl B, Prölß G, Kiriaev L, Head SI, Reid MB. Single muscle fibre biomechanics and biomechatronics - The challenges, the pitfalls and the future. Int J Biochem Cell Biol 2019; 114:105563. [PMID: 31255723 DOI: 10.1016/j.biocel.2019.105563] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Revised: 06/25/2019] [Accepted: 06/27/2019] [Indexed: 11/19/2022]
Abstract
Interest in muscle biomechanics is growing with availabilities of patient biopsies and animal models related to muscle diseases, muscle wasting (sarcopenia, cachexia), exercise and drug effects. However, development of technologies or facilitated systems required to measure biomechanical and contractile properties of single fibres has not kept pace with this demand. Most studies use manual mechatronics systems that have not changed in decades and are confined to a few labs worldwide. Available commercial systems are expensive and limited in versatility, throughput and user-friendliness. We review major standard systems available from research labs and commercial sources, and benchmark those to our recently developed automated MyoRobot biomechatronics platform that provides versatility to cover multiple organ scales, is flexible in programming for active/passive muscle biomechanics using custom-made graphics user interfaces, employs on-the-fly data analyses and does not rely on external research microscopes. With higher throughput, this system blends Industry 4.0 automation principles into myology.
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Affiliation(s)
- Oliver Friedrich
- Institute of Medical Biotechnology, Friedrich-Alexander University Erlangen-Nürnberg, Paul-Gordan-Str. 3, 91052 Erlangen, Germany; School of Medical Sciences, University of New South Wales (USNW), Wallace Wurth Building, 2052 NSW, Sydney Australia; Muscle Research Centre Erlangen (MURCE), Henkestr. 91, 91052 Erlangen, Germany.
| | - Michael Haug
- Institute of Medical Biotechnology, Friedrich-Alexander University Erlangen-Nürnberg, Paul-Gordan-Str. 3, 91052 Erlangen, Germany
| | - B Reischl
- Institute of Medical Biotechnology, Friedrich-Alexander University Erlangen-Nürnberg, Paul-Gordan-Str. 3, 91052 Erlangen, Germany
| | - G Prölß
- Institute of Medical Biotechnology, Friedrich-Alexander University Erlangen-Nürnberg, Paul-Gordan-Str. 3, 91052 Erlangen, Germany
| | - Leon Kiriaev
- School of Medical Sciences, University of New South Wales (USNW), Wallace Wurth Building, 2052 NSW, Sydney Australia
| | - Stewart I Head
- School of Medical Sciences, University of New South Wales (USNW), Wallace Wurth Building, 2052 NSW, Sydney Australia; Department of Physiology, School of Medicine, University of Western Sydney, Campbelltown Campus, Western Sydney, 2751 NSW, Australia
| | - Michael B Reid
- College of Health and Human Performance, University of Florida, Gainesville, FL, USA
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27
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Naro F, Venturelli M, Monaco L, Toniolo L, Muti E, Milanese C, Zhao J, Richardson RS, Schena F, Reggiani C. Skeletal Muscle Fiber Size and Gene Expression in the Oldest-Old With Differing Degrees of Mobility. Front Physiol 2019; 10:313. [PMID: 30971947 PMCID: PMC6443969 DOI: 10.3389/fphys.2019.00313] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Accepted: 03/07/2019] [Indexed: 12/22/2022] Open
Abstract
The oldest-old, in the ninth and tenth decades of their life, represent a population characterized by neuromuscular impairment, which often implies a loss of mobility and independence. As recently documented by us and others, muscle atrophy and weakness are accompanied by an unexpected preservation of the size and contractile function of skeletal muscle fibers. This suggests that, while most fibers are likely lost with their respective motoneurons, the surviving fibers are well preserved. Here, we investigated the mechanisms behind this fiber preservation and the relevance of physical activity, by comparing a group of 6 young healthy controls (YG: 22-28 years) with two groups of oldest-old (81-96 years), one able to walk (OW: n = 6, average 86 years) and one confined to a wheelchair (ONW n = 9, average 88 years). We confirmed previous results of fiber preservation and, additionally, observed a shift in fiber type, toward slow predominance in OW and fast predominance in ONW. Myonuclear density was increased in muscles of ONW, compared to YG and OW, potentially indicative of an ongoing atrophy process. We analyzed, by RT-qPCR, the expression of genes relevant for fiber size and type regulation in a biopsy sample from the vastus lateralis. In all oldest-old both myostatin and IGF-1 expression were attenuated compared to YG, however, in ONW two specific IGF-1 isoforms, IGF-1EA and MGF, demonstrated a further significant decrease compared to OW. Surprisingly, atrogenes (MURF1 and atrogin) expression was also significantly reduced compared to YG and this was accompanied by a close to statistically significantly attenuated marker of autophagy, LC3. Among the determinants of the metabolic fiber type, PGC1α was significantly reduced in both OW and ONW compared to YG, while AMPK was down-regulated only in ONW. We conclude that, in contrast to the shift of the balance in favor of pro-atrophy factors found by other studies in older adults (decreased IGF-1, increase of myostatin, increase of atrogenes), in the oldest-old the pro-atrophy factors also appear to be down-regulated, allowing a partial recovery of the proteostasis balance. Furthermore, the impact of muscle activity, as a consequence of lost or preserved walking ability, is limited.
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Affiliation(s)
- Fabio Naro
- Department of Anatomical, Histological, Forensic and Orthopedic Sciences, Sapienza University of Rome, Rome, Italy
| | - Massimo Venturelli
- Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Lucia Monaco
- Department of Physiology and Pharmacology, Sapienza University of Rome, Rome, Italy
| | - Luana Toniolo
- Department of Biomedical Sciences, University of Padova, Padua, Italy
| | - Ettore Muti
- Monsignor Arrigo Mazzali Foundation, Mantova, Italy
| | - Chiara Milanese
- Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Jia Zhao
- Division of Geriatrics, Department of Internal Medicine, The University of Utah, Salt Lake City, UT, United States.,Department of Nutrition and Integrative Physiology, The University of Utah, Salt Lake City, UT, United States.,Geriatric Research, Education, and Clinical Center, George E. Whalen VA Medical Center, Salt Lake City, UT, United States
| | - Russell S Richardson
- Division of Geriatrics, Department of Internal Medicine, The University of Utah, Salt Lake City, UT, United States.,Department of Nutrition and Integrative Physiology, The University of Utah, Salt Lake City, UT, United States.,Geriatric Research, Education, and Clinical Center, George E. Whalen VA Medical Center, Salt Lake City, UT, United States
| | - Federico Schena
- Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Carlo Reggiani
- Department of Biomedical Sciences, University of Padova, Padua, Italy.,Institute for Kinesiology Research, Science and Research Center of Koper, Koper, Slovenia
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28
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Muscle-specific activation of calpain system in hindlimb unloading rats and hibernating Daurian ground squirrels: a comparison between artificial and natural disuse. J Comp Physiol B 2018; 188:863-876. [PMID: 30039299 DOI: 10.1007/s00360-018-1176-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Revised: 06/14/2018] [Accepted: 07/17/2018] [Indexed: 01/28/2023]
Abstract
To determine whether the regulation of calpain system is involved in non-hibernators and hibernators in disused condition, the soleus (SOL) and extensor digitorum longus (EDL) muscles were used for investigating the muscle mass, the ratio of muscle wet weight/body weight (MWW/BW), fiber-type distribution, fiber cross-sectional area (CSA), and the protein expression of MuRF1, calpain-1, calpain-2, calpastatin, desmin, troponin T, and troponin C in hindlimb unloading rats and hibernating Daurian ground squirrels. The muscle mass, MWW/BW, and fiber CSA were found significantly decreased in SOL and EDL of hindlimb unloading rats, but unchanged in hibernating ground squirrels. The MuRF1 expression was increased in both SOL and EDL of unloading rats, while it was only increased in SOL, but maintained in EDL of hibernating ground squirrels. The expression levels of calpain-1 and calpain-2 were increased in different degrees in unloaded SOL and EDL in rats, while they were maintained in EDL and even reduced in SOL of hibernating ground squirrels. Besides, the expression of calpastatin was decreased in unloaded rats, but increased in hibernating ground squirrels. The desmin expression was decreased in unloaded rats, but maintained in hibernating squirrels. Interestingly, the levels of troponin T and troponin C were decreased in both SOL and EDL of unloaded rats, but increased in hibernating ground squirrels with muscle-type specificity. In conclusion, differential calpain activation and substrate-selective degradation in slow and fast muscles are involved in the mechanisms of muscle atrophy of unloaded rats and remarkable ability of muscle maintenance of hibernating ground squirrels.
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29
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Rejc E, Floreani M, Taboga P, Botter A, Toniolo L, Cancellara L, Narici M, Šimunič B, Pišot R, Biolo G, Passaro A, Rittweger J, Reggiani C, Lazzer S. Loss of maximal explosive power of lower limbs after 2 weeks of disuse and incomplete recovery after retraining in older adults. J Physiol 2018; 596:647-665. [PMID: 29266264 DOI: 10.1113/jp274772] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Accepted: 12/11/2017] [Indexed: 01/01/2023] Open
Abstract
KEY POINTS Disuse in older adults can critically decrease lower limb muscle power, leading to compromised mobility and overall quality of life. We studied how muscle power and its determinants (muscle mass, single muscle fibre properties and motor control) adapted to 2 weeks of disuse and subsequent 2 weeks of physical training in young and older people. Disuse decreased lower limb muscle power in both groups; however, different adaptations in single muscle fibre properties and co-contraction of leg muscles were observed between young and older individuals. Six physical training sessions performed after disuse promoted the recovery of muscle mass and power. However, they were not sufficient to restore muscle power to pre-disuse values in older individuals, suggesting that further countermeasures are required to counteract the disuse-induced loss of muscle power in older adults. ABSTRACT Disuse-induced loss of muscle power can be detrimental in older individuals, seriously impairing functional capacity. In this study, we examined the changes in maximal explosive power (MEP) of lower limbs induced by a 14-day disuse (bed-rest, BR) and a subsequent 14-day retraining, to assess whether the impact of disuse was greater in older than in young men, and to analyse the causes of such adaptations. Sixteen older adults (Old: 55-65 years) and seven Young (18-30 years) individuals participated in this study. In a subgroup of eight Old subjects, countermeasures based on cognitive training and protein supplementation were applied. MEP was measured with an explosive ergometer, muscle mass was determined by magnetic resonance, motor control was studied by EMG, and single muscle fibres were analysed in vastus lateralis biopsy samples. MEP was ∼33% lower in Old than in Young individuals, and remained significantly lower (-19%) when normalized by muscle volume. BR significantly affected MEP in Old (-15%) but not in Young. Retraining tended to increase MEP; however, this intervention was not sufficient to restore pre-BR values in Old. Ankle co-contraction increased after BR in Old only, and remained elevated after retraining (+30%). Significant atrophy occurred in slow fibres in Old, and in fast fibres in Young. After retraining, the recovery of muscle fibre thickness was partial. The proposed countermeasures were not sufficient to affect muscle mass and power. The greater impact of disuse and smaller retraining-induced recovery observed in Old highlight the importance of designing suitable rehabilitation protocols for older individuals.
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Affiliation(s)
- Enrico Rejc
- Department of Medicine, University of Udine, Udine, Italy.,Kentucky Spinal Cord Injury Research Center, University of Louisville, Louisville, KY, USA
| | - Mirco Floreani
- Department of Medicine, University of Udine, Udine, Italy.,School of Sport Sciences, University of Udine, Udine, Italy
| | - Paolo Taboga
- Department of Medicine, University of Udine, Udine, Italy.,Department of Kinesiology and Health Science, California State University, Sacramento, CA, USA
| | - Alberto Botter
- Department of Medicine, University of Udine, Udine, Italy.,School of Sport Sciences, University of Udine, Udine, Italy
| | - Luana Toniolo
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Lina Cancellara
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Marco Narici
- Department of Biomedical Sciences, University of Padova, Padova, Italy.,MRC/ARUK Centre for Musculoskeletal Ageing Research, University of Nottingham, Derby Royal Hospital, Derby, UK
| | - Boštjan Šimunič
- Institute for Kinesiology Research, Science and Research Center of Koper, Koper, Slovenia
| | - Rado Pišot
- Institute for Kinesiology Research, Science and Research Center of Koper, Koper, Slovenia
| | - Gianni Biolo
- Department of Medical Sciences, Surgical and Health Sciences, Clinica Medica AOUTS, University of Trieste, Italy
| | - Angelina Passaro
- Department of Medical Sciences, Section of Internal and Cardiorespiratory Medicine, University of Ferrara, Ferrara, Italy
| | - Joern Rittweger
- Institute of Aerospace Medicine, German Aerospace Center (DLR), Cologne, Germany
| | - Carlo Reggiani
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Stefano Lazzer
- Department of Medicine, University of Udine, Udine, Italy.,School of Sport Sciences, University of Udine, Udine, Italy
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30
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Age-related reduction in single muscle fiber calcium sensitivity is associated with decreased muscle power in men and women. Exp Gerontol 2017; 102:84-92. [PMID: 29247790 DOI: 10.1016/j.exger.2017.12.007] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Revised: 11/17/2017] [Accepted: 12/11/2017] [Indexed: 01/06/2023]
Abstract
Age-related declines in human skeletal muscle performance may be caused, in part, by decreased responsivity of muscle fibers to calcium (Ca2+). This study examined the contractile properties of single vastus lateralis muscle fibers with various myosin heavy chain (MHC) isoforms (I, I/IIA, IIA and IIAX) across a range of Ca2+ concentrations in 11 young (24.1±1.1years) and 10 older (68.8±0.8years) men and women. The normalized pCa-force curve shifted rightward with age, leading to decreased activation threshold (pCa10) and/or Ca2+ sensitivity (pCa50) for all MHC isoforms examined. In older adults, the slope of the pCa-force curve was unchanged in MHC I-containing fibers (I, I/IIA), but was steeper in MHC II-containing fibers (IIA, IIAX), indicating greater cooperativity compared to young adults. At sub-maximal [Ca2+], specific force was reduced in MHC I-containing fibers, but was minimally decreased in MHC IIA fibers as older adults produced greater specific forces at high [Ca2+] in these fibers. Lessor pCa50 in MHC I fibers independently predicted reduced isokinetic knee extensor power across a range of contractile velocities, suggesting that the Ca2+ response of slow-twitch fibers contributes to whole muscle dysfunction. Our findings show that aging attenuates Ca2+ responsiveness across fiber types and that these cellular alterations may lead to age-related reductions in whole muscle power output.
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31
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Dirks ML, Wall BT, van Loon LJC. Interventional strategies to combat muscle disuse atrophy in humans: focus on neuromuscular electrical stimulation and dietary protein. J Appl Physiol (1985) 2017; 125:850-861. [PMID: 28970205 DOI: 10.1152/japplphysiol.00985.2016] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Numerous situations, such as the recovery from illness or rehabilitation after injury, necessitate a period of muscle disuse in otherwise healthy individuals. Even a few days of immobilization or bed rest can lead to substantial loss of skeletal muscle tissue and compromise metabolic health. The decline in muscle mass is attributed largely to a decline in postabsorptive and postprandial muscle protein synthesis rates. Reintroduction of some level of muscle contraction by the application of neuromuscular electrical stimulation (NMES) can augment both postabsorptive and postprandial muscle protein synthesis rates and, as such, prevent or attenuate muscle loss during short-term disuse in various clinical populations. Whereas maintenance of habitual dietary protein consumption is a prerequisite for muscle mass maintenance, supplementing dietary protein above habitual intake levels does not prevent muscle loss during disuse in otherwise healthy humans. Combining the anabolic properties of physical activity (or surrogates) with appropriate nutritional support likely further increases the capacity to preserve skeletal muscle mass during a period of disuse. Therefore, effective interventional strategies to prevent or alleviate muscle disuse atrophy should include both exercise (mimetics) and appropriate nutritional support.
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Affiliation(s)
- Marlou L Dirks
- NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, Maastricht , The Netherlands
| | - Benjamin T Wall
- NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, Maastricht , The Netherlands
| | - Luc J C van Loon
- NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, Maastricht , The Netherlands
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Arazpour M, Soflaei M, Ahmadi Bani M, Madani SP, Sattari M, Biglarian A, Mosallanezhad Z. The effect of thumb splinting on thenar muscles atrophy, pain, and function in subjects with thumb carpometacarpal joint osteoarthritis. Prosthet Orthot Int 2017; 41:379-386. [PMID: 27647603 DOI: 10.1177/0309364616664149] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
BACKGROUND When the first carpometacarpal joint of the wrist is immobilized using an orthosis to combat the effects of osteoarthritis, atrophy of the thenar muscles may occur. OBJECTIVES The aim of this study was to evaluate the thenar muscle diameter and cross-sectional area, joint function, and pain, before and after being supplied with an orthosis in patients with grades 1 and 2 carpometacarpal osteoarthritis compared to a control group. STUDY DESIGN Randomized clinical trial. METHODS A total of 25 volunteer patients were randomized into two groups (an orthosis group and a control group) using a randomization table. A visual analog scale, the Michigan Hand Questionnaire, and ultrasound were used to measure pain, function, and specific muscle cross-sectional areas at baseline and after 4 weeks in both groups. RESULTS Mean visual analog scale pain scores decreased by 20% after 4 weeks of splinting, while those in the control group decreased by 3%. Changes in scores were significantly different between both groups ( p = 0.001). There was no significant difference between the groups in either the Michigan Hand Questionnaire score or the muscle cross-sectional area. CONCLUSION A large and significant effect on perceived pain in patients with first carpometacarpal joint osteoarthritis was observed after 4 weeks of splint use. Differences in treatment effects were found with regard to muscle cross-sectional areas, but these were not significant. Clinical relevance Custom-made splints may be recommended for the treatment of first carpometacarpal joint osteoarthritis. Moderate to large but non-significant treatment effects were found with regard to muscle cross-sectional areas.
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Affiliation(s)
- Mokhtar Arazpour
- 1 Pediatric Neurorehabilitation Research Center, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran.,2 University of Social Welfare and Rehabilitation Sciences, Tehran, Islamic Republic of Iran
| | - Mohaddeseh Soflaei
- 2 University of Social Welfare and Rehabilitation Sciences, Tehran, Islamic Republic of Iran
| | - Monireh Ahmadi Bani
- 2 University of Social Welfare and Rehabilitation Sciences, Tehran, Islamic Republic of Iran
| | | | - Mahsa Sattari
- 4 Zanjan University of Medical Sciences, Zanjan, Islamic Republic of Iran
| | - Akbar Biglarian
- 2 University of Social Welfare and Rehabilitation Sciences, Tehran, Islamic Republic of Iran
| | - Zahra Mosallanezhad
- 2 University of Social Welfare and Rehabilitation Sciences, Tehran, Islamic Republic of Iran
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Voluntary activation of the trapezius muscle in cases with neck/shoulder pain compared to healthy controls. J Electromyogr Kinesiol 2017; 36:56-64. [PMID: 28735103 DOI: 10.1016/j.jelekin.2017.07.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Revised: 07/12/2017] [Accepted: 07/13/2017] [Indexed: 11/22/2022] Open
Abstract
Subjects reporting neck/shoulder pain have been shown to generate less force during maximal voluntary isometric contractions (MVC) of the shoulder muscles compared to healthy controls. This has been suggested to be caused by a pain-related decrease in voluntary activation (VA) rather than lack of muscle mass. The aim of the present study was to investigate VA of the trapezius muscle during MVCs in subjects with and without neck/shoulder pain by use of the twitch interpolation technique. Ten cases suffering from pain and ten age and gender matched, healthy controls were included in the study. Upper trapezius muscle thickness was measured using ultrasonography and pain intensity was measured on a 100mm visual analog scale (VAS). VA was calculated from five maximal muscle activation attempts. Superimposed stimuli were delivered to the accessory nerve at peak force and during a 2% MVC following the maximal contraction. Presented as mean±SD for cases and controls, respectively: VAS; 16.0±14.4mm and 2.1±4.1mm (P=0.004), MVC; 545±161N and 664±195N (P=0.016), upper trapezius muscle thickness; 10.9±1.9mm and 10.4±1.5mm (P=0.20), VA; 93.6±14.2% and 96.3±6.0% (P=0.29). In spite of significantly eight-fold higher pain intensity and ∼20% lower MVC for cases compared to controls, no difference was found in VA. Possible explanations for the reduction in MVC could be differences in co-activation of antagonists and synergists as well as muscle quality.
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Brocca L, McPhee JS, Longa E, Canepari M, Seynnes O, De Vito G, Pellegrino MA, Narici M, Bottinelli R. Structure and function of human muscle fibres and muscle proteome in physically active older men. J Physiol 2017; 595:4823-4844. [PMID: 28452077 DOI: 10.1113/jp274148] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Accepted: 04/21/2017] [Indexed: 12/20/2022] Open
Abstract
KEY POINTS Loss of muscle mass and strength in the growing population of elderly people is a major health concern for modern societies. This condition, termed sarcopenia, is a major cause of falls and of the subsequent increase in morbidity and mortality. Despite numerous studies on the impact of ageing on individual muscle fibres, the contribution of single muscle fibre adaptations to ageing-induced atrophy and functional impairment is still unsettled. The level of physical function and disuse is often associated with ageing. We studied relatively healthy older adults in order to understand the effects of ageing per se without the confounding impact of impaired physical function. We found that in healthy ageing, structural and functional alterations of muscle fibres occur. Protein post-translational modifications, oxidation and phosphorylation contribute to such alterations more than loss of myosin and other muscle protein content. ABSTRACT Contradictory results have been reported on the impact of ageing on structure and functions of skeletal muscle fibres, likely to be due to a complex interplay between ageing and other phenomena such as disuse and diseases. Here we recruited healthy, physically and socially active young (YO) and elderly (EL) men in order to study ageing per se without the confounding effects of impaired physical function. In vivo analyses of quadriceps and in vitro analyses of vastus lateralis muscle biopsies were performed. In EL subjects, our results show that (i) quadriceps volume, maximum voluntary contraction isometric torque and patellar tendon force were significantly lower; (ii) muscle fibres went through significant atrophy and impairment of specific force (isometric force/cross-sectional area) and unloaded shortening velocity; (iii) myosin/actin ratio and myosin content in individual muscle fibres were not altered; (iv) the muscle proteome went through quantitative adaptations, namely an up-regulation of the content of several groups of proteins among which were myofibrillar proteins and antioxidant defence systems; (v) the muscle proteome went through qualitative adaptations, namely phosphorylation of several proteins, including myosin light chain-2 slow and troponin T and carbonylation of myosin heavy chains. The present results indicate that impairment of individual muscle fibre structure and function is a major feature of ageing per se and that qualitative adaptations of muscle proteome are likely to be more involved than quantitative adaptations in determining such a phenomenon.
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Affiliation(s)
- Lorenza Brocca
- Department of Molecular Medicine, University of Pavia, Pavia, Italy.,Interuniversity Institute of Myology, University of Pavia, Pavia, Italy
| | - Jamie S McPhee
- School of Healthcare Science, Manchester Metropolitan University, Manchester, UK
| | - Emanuela Longa
- Department of Molecular Medicine, University of Pavia, Pavia, Italy
| | - Monica Canepari
- Department of Molecular Medicine, University of Pavia, Pavia, Italy.,Interuniversity Institute of Myology, University of Pavia, Pavia, Italy
| | - Olivier Seynnes
- Department of Physical Performance, Norwegian School of Sport Sciences, Oslo, Norway
| | - Giuseppe De Vito
- Institute for Sport and Health, University College Dublin, Ireland
| | - Maria Antonietta Pellegrino
- Department of Molecular Medicine, University of Pavia, Pavia, Italy.,Interuniversity Institute of Myology, University of Pavia, Pavia, Italy.,Interdipartimental Centre for Biology and Sport Medicine, University of Pavia, Pavia, Italy
| | - Marco Narici
- School of Graduate Entry to Medicine and Health, Division of Clinical Physiology, University of Nottingham, Derby, UK
| | - Roberto Bottinelli
- Department of Molecular Medicine, University of Pavia, Pavia, Italy.,Interdipartimental Centre for Biology and Sport Medicine, University of Pavia, Pavia, Italy.,Fondazione Salvatore Maugeri (IRCCS), Scientific Institute of Pavia, Pavia, Italy
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Chang H, Jiang SF, Dang K, Wang HP, Xu SH, Gao YF. iTRAQ-based proteomic analysis of myofibrillar contents and relevant synthesis and proteolytic proteins in soleus muscle of hibernating Daurian ground squirrels ( Spermophilus dauricus). Proteome Sci 2016; 14:16. [PMID: 27833457 PMCID: PMC5101720 DOI: 10.1186/s12953-016-0105-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Accepted: 11/01/2016] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND Daurian ground squirrels (Spermophilus dauricus) deviate from significant increase of protein catabolism and loss of myofibrillar contents during long period of hibernation inactivity. METHODS Here we use iTRAQ based quantitative analysis to examine proteomic changes in the soleus of squirrels in pre-hibernation, hibernation and post-hibernation states. The total proteolysis rate of soleus was measured by the release of the essential amino acid tyrosine from isolated muscles. Immunofluorescent analysis was used to determine muscle fiber cross-sectional area. Western blot was used for the validation of the quantitative proteomic analysis. RESULTS The proteomic responses to hibernation had a 0.4- to 0.8-fold decrease in the myofibrillar contractile protein levels of myosin-3, myosin-13 and actin, but a 2.1-fold increase in myosin-2 compared to pre-hibernation group. Regulatory proteins such as troponin C and tropomodulin-1 were 1.4-fold up-regulated and 0.7-fold down-regulated, respectively, in hibernation compared to pre-hibernation group. Moreover, 10 proteins with proteolytic function in hibernation, which was less than 14 proteins in the post-hibernation group, were up-regulated relative to the pre-hibernation group. The total proteolysis rates of soleus in hibernation and post-hibernation groups were significantly inhibited as compared with pre-hibernation group. CONCLUSION These findings suggest that the myofibrillar remodeling and partial suppression of myofibrillar proteolysis were likely responsible for preventing skeletal muscle atrophy during prolonged disuse in hibernation. This is the first study where the myofibrillar contents and relevant synthesis and proteolytic proteins in slow soleus was discussed based on proteomic investigation performed on wild Daurian ground squirrels. Our results lay the foundation for further research in preventing disuse-induced skeletal muscle atrophy in mammals.
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Affiliation(s)
- Hui Chang
- Key Laboratory of Resource Biology and Biotechnology in Western China (College of Life Sciences, Northwest University), Ministry of Education, Xi’an, 710069 People’s Republic of China
- Shaanxi Key Laboratory for Animal Conservation, Northwest University, Xi’an, 710069 People’s Republic of China
| | - Shan-Feng Jiang
- Key Laboratory of Resource Biology and Biotechnology in Western China (College of Life Sciences, Northwest University), Ministry of Education, Xi’an, 710069 People’s Republic of China
| | - Kai Dang
- Key Laboratory of Resource Biology and Biotechnology in Western China (College of Life Sciences, Northwest University), Ministry of Education, Xi’an, 710069 People’s Republic of China
| | - Hui-Ping Wang
- Key Laboratory of Resource Biology and Biotechnology in Western China (College of Life Sciences, Northwest University), Ministry of Education, Xi’an, 710069 People’s Republic of China
| | - Shen-Hui Xu
- Key Laboratory of Resource Biology and Biotechnology in Western China (College of Life Sciences, Northwest University), Ministry of Education, Xi’an, 710069 People’s Republic of China
| | - Yun-Fang Gao
- Key Laboratory of Resource Biology and Biotechnology in Western China (College of Life Sciences, Northwest University), Ministry of Education, Xi’an, 710069 People’s Republic of China
- Shaanxi Key Laboratory for Animal Conservation, Northwest University, Xi’an, 710069 People’s Republic of China
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36
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Hvid LG, Brocca L, Ørtenblad N, Suetta C, Aagaard P, Kjaer M, Bottinelli R, Pellegrino MA. Myosin content of single muscle fibers following short-term disuse and active recovery in young and old healthy men. Exp Gerontol 2016; 87:100-107. [PMID: 27794458 DOI: 10.1016/j.exger.2016.10.009] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Revised: 10/05/2016] [Accepted: 10/24/2016] [Indexed: 01/11/2023]
Abstract
Short-term disuse and subsequent recovery affect whole muscle and single myofiber contractile function in young and old. While the loss and recovery of single myofiber specific force (SF) following disuse and rehabilitation has been shown to correlate with alterations in myosin concentrations in young, it is unknown whether similar relationships exist in old. Therefore, the purpose of the present study was to examine the effect of 14days lower limb disuse followed by 28days of active recovery on single muscle fiber myosin content in old (68yrs) and young (24yrs) recreationally physically active healthy men. Following disuse, myosin content decreased (p<0.05) in MHC 1 (young -28%, old -19%) and 2a fibers (young -23%, old -32%). In old, myosin content decreased more (p<0.05) in MHC 2a vs 1 fibers. Following recovery, myosin content increased (p<0.05) and returned to pre-disuse levels for both young and old in both fiber types, with MHC 2a fibers demonstrating an overshooting in young (+31%, p<0.05) but not old. Strong correlations were observed between myosin content and single fiber SF in both young and old, with greater slope steepness in MHC 2a vs 1 fibers indicating an enhanced intrinsic contractile capacity of MHC 2a fibers. In conclusion, adaptive changes in myofiber myosin content appear to occur rapidly following brief periods of disuse (2wks) and after subsequent active recovery (4wks) in young and old, which contribute to alterations in contractile function at the single muscle fiber level. Changes in myosin content appear to occur independently of age, while influenced by fiber type (MHC isoform) in young but not old.
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Affiliation(s)
- Lars G Hvid
- Department of Sports Science and Clinical Biomechanics, University of Southern Denmark (SDU), Denmark.
| | - Lorenza Brocca
- Department of Molecular Medicine, University of Pavia, Italy
| | - Niels Ørtenblad
- Department of Sports Science and Clinical Biomechanics, University of Southern Denmark (SDU), Denmark; Swedish Winter Sports Research Centre, Department of Health Sciences, Mid Sweden University, Sweden
| | - Charlotte Suetta
- Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet Glostrup, University of Copenhagen, Denmark
| | - Per Aagaard
- Department of Sports Science and Clinical Biomechanics, University of Southern Denmark (SDU), Denmark
| | - Michael Kjaer
- Institute of Sports Medicine, Copenhagen and Center of Healthy Aging, Bispebjerg Hospital, University of Copenhagen, Denmark
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37
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Lamboley CR, Wyckelsma VL, Perry BD, McKenna MJ, Lamb GD. Effect of 23-day muscle disuse on sarcoplasmic reticulum Ca2+ properties and contractility in human type I and type II skeletal muscle fibers. J Appl Physiol (1985) 2016; 121:483-92. [DOI: 10.1152/japplphysiol.00337.2016] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Accepted: 06/28/2016] [Indexed: 11/22/2022] Open
Abstract
Inactivity negatively impacts on skeletal muscle function mainly through muscle atrophy. However, recent evidence suggests that the quality of individual muscle fibers is also altered. This study examined the effects of 23 days of unilateral lower limb suspension (ULLS) on specific force and sarcoplasmic reticulum (SR) Ca2+ content in individual skinned muscle fibers. Muscle biopsies of the vastus lateralis were taken from six young healthy adults prior to and following ULLS. After disuse, the endogenous SR Ca2+ content was ∼8% lower in type I fibers and maximal SR Ca2+ capacity was lower in both type I and type II fibers (−11 and −5%, respectively). The specific force, measured in single skinned fibers from three subjects, decreased significantly after ULLS in type II fibers (−23%) but not in type I fibers (−9%). Western blot analyses showed no significant change in the amounts of myosin heavy chain (MHC) I and MHC IIa following the disuse, whereas the amounts of sarco(endo)plasmic reticulum Ca2+-ATPase 1 (SERCA1) and calsequestrin increased by ∼120 and ∼20%, respectively, and the amount of troponin I decreased by ∼21%. These findings suggest that the decline in force and power occurring with muscle disuse is likely to be exacerbated in part by reductions in maximum specific force in type II fibers, and in the amount of releasable SR Ca2+ in both fiber types, the latter not being attributable to a reduced calsequestrin level. Furthermore, the ∼3-wk disuse in human elicits change in SR properties, in particular a more than twofold upregulation in SERCA1 density, before any fiber-type shift.
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Affiliation(s)
- C. R. Lamboley
- Institute of Sport, Exercise and Active Living, Victoria University, Melbourne, Victoria, Australia
- School of Life Sciences, La Trobe University, Melbourne, Victoria, Australia
| | - V. L. Wyckelsma
- Institute of Sport, Exercise and Active Living, Victoria University, Melbourne, Victoria, Australia
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria, Australia; and
| | - B. D. Perry
- Institute of Sport, Exercise and Active Living, Victoria University, Melbourne, Victoria, Australia
- Renal Division, Department of Medicine, Emory University, Atlanta, Georgia
| | - M. J. McKenna
- Institute of Sport, Exercise and Active Living, Victoria University, Melbourne, Victoria, Australia
| | - G. D. Lamb
- School of Life Sciences, La Trobe University, Melbourne, Victoria, Australia
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38
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Fu W, Hu H, Dang K, Chang H, Du B, Wu X, Gao Y. Remarkable preservation of Ca(2+) homeostasis and inhibition of apoptosis contribute to anti-muscle atrophy effect in hibernating Daurian ground squirrels. Sci Rep 2016; 6:27020. [PMID: 27256167 PMCID: PMC4891705 DOI: 10.1038/srep27020] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Accepted: 05/12/2016] [Indexed: 01/16/2023] Open
Abstract
The underlying mechanisms that hibernators deviated from muscle atrophy during prolonged hibernating inactivity remain elusive. This study tested the hypothesis that the maintenance of intracellular Ca2+ homeostasis and inhibition of apoptosis would be responsible for preventing muscle atrophy in hibernating Daurian ground squirrels. The results showed that intracellular Ca2+ homeostasis was maintained in soleus and extensor digitorum longus (EDL) in hibernation and post-hibernation, while cytosolic Ca2+ was overloaded in gastrocnemius (GAS) in hibernation with a recovery in post-hibernation. The Ca2+ overload was also observed in interbout arousals in all three type muscles. Besides, the Bax/Bcl-2 ratio was unchanged in transcriptional level among pre-hibernation, hibernation and interbout arousals, and reduced to a minimum in post-hibernation. Furthermore, the Bax/Bcl-2 ratio in protein level was reduced in hibernation but recovered in interbout arousals. Although cytochrome C was increased in GAS and EDL in post-hibernation, no apoptosis was observed by TUNEL assay. These findings suggested that the intracellular Ca2+ homeostasis in hibernation might be regulated by the cytosolic Ca2+ overload during interbout arousals, which were likely responsible for preventing muscle atrophy via inhibition of apoptosis. Moreover, the muscle-specificity indicated that the different mechanisms against disuse-induced atrophy might be involved in different muscles in hibernation.
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Affiliation(s)
- Weiwei Fu
- Key Laboratory of Resource Biology and Biotechnology in Western China (Northwest University), Ministry of Education, Xi'an 710069, China
| | - Huanxin Hu
- National Research Center for Veterinary Medicine, Luo Yang 471003, China
| | - Kai Dang
- Key Laboratory of Resource Biology and Biotechnology in Western China (Northwest University), Ministry of Education, Xi'an 710069, China
| | - Hui Chang
- Key Laboratory of Resource Biology and Biotechnology in Western China (Northwest University), Ministry of Education, Xi'an 710069, China
| | - Bei Du
- Shaanxi Institute of International Trade and Commerce, Xian Yang 712046, China
| | - Xue Wu
- Department of Burns and Cutaneous Surgery, Xijing Hospital, Fourth Military Medical University, Xi'an 710032, China
| | - Yunfang Gao
- Key Laboratory of Resource Biology and Biotechnology in Western China (Northwest University), Ministry of Education, Xi'an 710069, China
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39
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Maffiuletti NA, Aagaard P, Blazevich AJ, Folland J, Tillin N, Duchateau J. Rate of force development: physiological and methodological considerations. Eur J Appl Physiol 2016; 116:1091-116. [PMID: 26941023 PMCID: PMC4875063 DOI: 10.1007/s00421-016-3346-6] [Citation(s) in RCA: 748] [Impact Index Per Article: 93.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Accepted: 02/17/2016] [Indexed: 11/26/2022]
Abstract
The evaluation of rate of force development during rapid contractions has recently become quite popular for characterising explosive strength of athletes, elderly individuals and patients. The main aims of this narrative review are to describe the neuromuscular determinants of rate of force development and to discuss various methodological considerations inherent to its evaluation for research and clinical purposes. Rate of force development (1) seems to be mainly determined by the capacity to produce maximal voluntary activation in the early phase of an explosive contraction (first 50–75 ms), particularly as a result of increased motor unit discharge rate; (2) can be improved by both explosive-type and heavy-resistance strength training in different subject populations, mainly through an improvement in rapid muscle activation; (3) is quite difficult to evaluate in a valid and reliable way. Therefore, we provide evidence-based practical recommendations for rational quantification of rate of force development in both laboratory and clinical settings.
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Affiliation(s)
- Nicola A Maffiuletti
- Human Performance Lab, Schulthess Clinic, Lengghalde 6, 8008, Zurich, Switzerland.
| | - Per Aagaard
- Department of Sports Science and Clinical Biomechanics, SDU Muscle Research Cluster (SMRC), University of Southern Denmark, Odense, Denmark
| | - Anthony J Blazevich
- Centre for Exercise and Sports Science Research (CESSR), School of Medical and Health Sciences, Edith Cowan University, Joondalup, Australia
| | - Jonathan Folland
- School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UK
| | - Neale Tillin
- Department of Life Sciences, University of Roehampton, London, UK
| | - Jacques Duchateau
- Laboratory of Applied Biology, ULB Neurosciences Institute, Université Libre de Bruxelles (ULB), Brussels, Belgium
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40
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Lamboley CR, Wyckelsma VL, McKenna MJ, Murphy RM, Lamb GD. Ca(2+) leakage out of the sarcoplasmic reticulum is increased in type I skeletal muscle fibres in aged humans. J Physiol 2015; 594:469-81. [PMID: 26574292 DOI: 10.1113/jp271382] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Accepted: 11/11/2015] [Indexed: 12/16/2022] Open
Abstract
KEY POINTS The amount of Ca(2+) stored in the sarcoplasmic reticulum (SR) of muscle fibres is decreased in aged individuals, and an important question is whether this results from increased Ca(2+) leakage out through the Ca(2+) release channels (ryanodine receptors; RyRs). The present study examined the effects of blocking the RyRs with Mg(2+), or applying a strong reducing treatment, on net Ca(2+) accumulation by the SR in skinned muscle fibres from Old (∼70 years) and Young (∼24 years) adults. Raising cytoplasmic [Mg(2+)] and reducing treatment increased net SR Ca(2+) accumulation in type I fibres of Old subjects relative to that in Young. The densities of RyRs and dihydropyridine receptors were not significantly changed in the muscle of Old subjects. These findings indicate that oxidative modification of the RyRs causes increased Ca(2+) leakage from the SR in muscle fibres in Old subjects, which probably deleteriously affects normal muscle function both directly and indirectly. ABSTRACT The present study examined whether the lower Ca(2+) storage levels in the sarcoplasmic reticulum (SR) in vastus lateralis muscle fibres in Old (70 ± 4 years) relative to Young (24 ± 4 years) human subjects is the result of increased leakage of Ca(2+) out of the SR through the Ca(2+) release channels/ryanodine receptors (RyRs) and due to oxidative modification of the RyRs. SR Ca(2+) accumulation in mechanically skinned muscle fibres was examined in the presence of 1, 3 or 10 mm cytoplasmic Mg(2+) because raising [Mg(2+)] strongly inhibits Ca(2+) efflux through the RyRs. In type I fibres of Old subjects, SR Ca(2+) accumulation in the presence of 1 mm Mg(2+) approached saturation at shorter loading times than in Young subjects, consistent with Ca(2+) leakage limiting net uptake, and raising [Mg(2+)] to 10 mm in such fibres increased maximal SR Ca(2+) accumulation. No significant differences were seen in type II fibres. Treatment with dithiothreitol (10 mm for 5 min), a strong reducing agent, also increased maximal SR Ca(2+) accumulation at 1 mm Mg(2+) in type I fibres of Old subjects but not in other fibres. The densities of dihydropyridine receptors and RyRs were not significantly different in muscles of Old relative to Young subjects. These findings indicate that Ca(2+) leakage from the SR is increased in type I fibres in Old subjects by reversible oxidative modification of the RyRs; this increased SR Ca(2+) leak is expected to have both direct and indirect deleterious effects on Ca(2+) movements and muscle function.
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Affiliation(s)
- C R Lamboley
- Institute of Sport, Exercise and Active Living (ISEAL), Victoria University, Melbourne, VIC, Australia.,School of Life Sciences, La Trobe University, Melbourne, VIC 3086, Australia
| | - V L Wyckelsma
- Institute of Sport, Exercise and Active Living (ISEAL), Victoria University, Melbourne, VIC, Australia.,Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC, Australia
| | - M J McKenna
- Institute of Sport, Exercise and Active Living (ISEAL), Victoria University, Melbourne, VIC, Australia
| | - R M Murphy
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC, Australia
| | - G D Lamb
- School of Life Sciences, La Trobe University, Melbourne, VIC 3086, Australia
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41
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Venturelli M, Saggin P, Muti E, Naro F, Cancellara L, Toniolo L, Tarperi C, Calabria E, Richardson RS, Reggiani C, Schena F. In vivo and in vitro evidence that intrinsic upper- and lower-limb skeletal muscle function is unaffected by ageing and disuse in oldest-old humans. Acta Physiol (Oxf) 2015; 215:58-71. [PMID: 25965867 DOI: 10.1111/apha.12524] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2015] [Revised: 02/06/2015] [Accepted: 05/07/2015] [Indexed: 12/17/2022]
Abstract
AIM To parse out the impact of advanced ageing and disuse on skeletal muscle function, we utilized both in vivo and in vitro techniques to comprehensively assess upper- and lower-limb muscle contractile properties in 8 young (YG; 25 ± 6 years) and 8 oldest-old mobile (OM; 87 ± 5 years) and 8 immobile (OI; 88 ± 4 years) women. METHODS In vivo, maximal voluntary contraction (MVC), electrically evoked resting twitch force (RT), and physiological cross-sectional area (PCSA) of the quadriceps and elbow flexors were assessed. Muscle biopsies of the vastus lateralis and biceps brachii facilitated the in vitro assessment of single fibre-specific tension (Po). RESULTS In vivo, compared to the young, both the OM and OI exhibited a more pronounced loss of MVC in the lower limb [OM (-60%) and OI (-75%)] than the upper limb (OM = -51%; OI = -47%). Taking into account the reduction in muscle PCSA (OM = -10%; OI = -18%), only evident in the lower limb, by calculating voluntary muscle-specific force, the lower limb of the OI (-40%) was more compromised than the OM (-13%). However, in vivo, RT in both upper and lower limbs (approx. 9.8 N m cm(-2) ) and Po (approx. 123 mN mm(-2) ), assessed in vitro, implies preserved intrinsic contractile function in all muscles of the oldest-old and were well correlated (r = 0.81). CONCLUSION These findings suggest that in the oldest-old, neither advanced ageing nor disuse, per se, impacts intrinsic skeletal muscle function, as assessed in vitro. However, in vivo, muscle function is attenuated by age and exacerbated by disuse, implicating factors other than skeletal muscle, such as neuromuscular control, in this diminution of function.
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Affiliation(s)
- M. Venturelli
- Department of Biomedical Sciences for Health; University of Milan; Milan Italy
- Department of Neurological, and Movement Sciences; University of Verona; Verona Italy
| | - P. Saggin
- Division of Radiology and Imaging; City of Verona Diagnostic Center; Verona Italy
| | - E. Muti
- Mons. Mazzali Foundation; Mantova Italy
| | - F. Naro
- DAHFMO Unit of Histology and Medical Embryology; Sapienza University; Rome Italy
| | - L. Cancellara
- Department of Biomedical Sciences; University of Padova; Padova Italy
| | - L. Toniolo
- Department of Biomedical Sciences; University of Padova; Padova Italy
| | - C. Tarperi
- Department of Neurological, and Movement Sciences; University of Verona; Verona Italy
| | - E. Calabria
- Department of Neurological, and Movement Sciences; University of Verona; Verona Italy
| | - R. S. Richardson
- Division of Geriatrics; Department of Internal Medicine; University of Utah School of Medicine; Salt Lake City UT USA
- Geriatric Research, Education, and Clinical Center; George E. Wahlen Department of Veterans Affairs Medical Center; Salt Lake City UT USA
- Department of Exercise and Sport Science; University of Utah; Salt Lake City UT USA
| | - C. Reggiani
- Department of Biomedical Sciences; University of Padova; Padova Italy
- CNR (Consiglio Nazionale delle Ricerche); Institute of Neuroscience; Padua Italy
| | - F. Schena
- Department of Neurological, and Movement Sciences; University of Verona; Verona Italy
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42
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Grounds MD, Pinniger GJ. What is the mechanism for in vivo loss of skeletal muscle function in elderly women? Acta Physiol (Oxf) 2015; 215:9-12. [PMID: 26132503 DOI: 10.1111/apha.12547] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- M. D. Grounds
- School of Anatomy, Physiology and Human Biology; The University of Western Australia; Perth WA Australia
| | - G. J. Pinniger
- School of Anatomy, Physiology and Human Biology; The University of Western Australia; Perth WA Australia
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Olsson K, Cheng AJ, Alam S, Al-Ameri M, Rullman E, Westerblad H, Lanner JT, Bruton JD, Gustafsson T. Intracellular Ca(2+)-handling differs markedly between intact human muscle fibers and myotubes. Skelet Muscle 2015; 5:26. [PMID: 26301072 PMCID: PMC4545874 DOI: 10.1186/s13395-015-0050-x] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Accepted: 07/21/2015] [Indexed: 12/14/2022] Open
Abstract
Background In skeletal muscle, intracellular Ca2+ is an important regulator of contraction as well as gene expression and metabolic processes. Because of the difficulties to obtain intact human muscle fibers, human myotubes have been extensively employed for studies of Ca2+-dependent processes in human adult muscle. Despite this, it is unknown whether the Ca2+-handling properties of myotubes adequately represent those of adult muscle fibers. Methods To enable a comparison of the Ca2+-handling properties of human muscle fibers and myotubes, we developed a model of dissected intact single muscle fibers obtained from human intercostal muscle biopsies. The intracellular Ca2+-handling of human muscle fibers was compared with that of myotubes generated by the differentiation of primary human myoblasts obtained from vastus lateralis muscle biopsies. Results The intact single muscle fibers all demonstrated strictly regulated cytosolic free [Ca2+] ([Ca2+]i) transients and force production upon electrical stimulation. In contrast, despite a more mature Ca2+-handling in myotubes than in myoblasts, myotubes lacked fundamental aspects of adult Ca2+-handling and did not contract. These functional differences were explained by discrepancies in the quantity and localization of Ca2+-handling proteins, as well as ultrastructural differences between muscle fibers and myotubes. Conclusions Intact single muscle fibers that display strictly regulated [Ca2+]i transients and force production upon electrical stimulation can be obtained from human intercostal muscle biopsies. In contrast, human myotubes lack important aspects of adult Ca2+-handling and are thus an inappropriate model for human adult muscle when studying Ca2+-dependent processes, such as gene expression and metabolic processes. Electronic supplementary material The online version of this article (doi:10.1186/s13395-015-0050-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Karl Olsson
- Department of Laboratory Medicine, Karolinska Institutet, Karolinska University Hospital Huddinge, Stockholm, 141 86 Sweden ; Department of Physiology and Pharmacology, Karolinska Institutet, von Eulers väg 8, Stockholm, 171 77 Sweden
| | - Arthur J Cheng
- Department of Physiology and Pharmacology, Karolinska Institutet, von Eulers väg 8, Stockholm, 171 77 Sweden
| | - Seher Alam
- Department of Laboratory Medicine, Karolinska Institutet, Karolinska University Hospital Huddinge, Stockholm, 141 86 Sweden
| | - Mamdoh Al-Ameri
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Karolinska University Hospital Solna, Stockholm, 171 76 Sweden
| | - Eric Rullman
- Department of Laboratory Medicine, Karolinska Institutet, Karolinska University Hospital Huddinge, Stockholm, 141 86 Sweden
| | - Håkan Westerblad
- Department of Physiology and Pharmacology, Karolinska Institutet, von Eulers väg 8, Stockholm, 171 77 Sweden
| | - Johanna T Lanner
- Department of Physiology and Pharmacology, Karolinska Institutet, von Eulers väg 8, Stockholm, 171 77 Sweden
| | - Joseph D Bruton
- Department of Physiology and Pharmacology, Karolinska Institutet, von Eulers väg 8, Stockholm, 171 77 Sweden
| | - Thomas Gustafsson
- Department of Laboratory Medicine, Karolinska Institutet, Karolinska University Hospital Huddinge, Stockholm, 141 86 Sweden
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44
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Gejl KD, Hvid LG, Willis SJ, Andersson E, Holmberg HC, Jensen R, Frandsen U, Hansen J, Plomgaard P, Ørtenblad N. Repeated high-intensity exercise modulates Ca2+sensitivity of human skeletal muscle fibers. Scand J Med Sci Sports 2015; 26:488-97. [DOI: 10.1111/sms.12483] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/26/2015] [Indexed: 12/17/2022]
Affiliation(s)
- K. D. Gejl
- Department of Sports Science and Clinical Biomechanics; SDU Muscle Research Cluster; University of Southern Denmark; Odense Denmark
| | - L. G. Hvid
- Department of Sports Science and Clinical Biomechanics; SDU Muscle Research Cluster; University of Southern Denmark; Odense Denmark
| | - S. J. Willis
- Department of Health Sciences; Swedish Winter Sports Research Centre; Mid Sweden University; Östersund Sweden
| | - E. Andersson
- Department of Health Sciences; Swedish Winter Sports Research Centre; Mid Sweden University; Östersund Sweden
| | - H.-C. Holmberg
- Department of Health Sciences; Swedish Winter Sports Research Centre; Mid Sweden University; Östersund Sweden
- Swedish Olympic Committee; Stockholm Sweden
| | - R. Jensen
- Department of Sports Science and Clinical Biomechanics; SDU Muscle Research Cluster; University of Southern Denmark; Odense Denmark
| | - U. Frandsen
- Department of Sports Science and Clinical Biomechanics; SDU Muscle Research Cluster; University of Southern Denmark; Odense Denmark
| | - J. Hansen
- Department of Infectious Diseases and CMRC; The Centre of Inflammation and Metabolism; Rigshospitalet; Copenhagen Denmark
- Department of Clinical Biochemistry; Rigshospitalet; Copenhagen Denmark
| | - P. Plomgaard
- Department of Infectious Diseases and CMRC; The Centre of Inflammation and Metabolism; Rigshospitalet; Copenhagen Denmark
- Department of Clinical Biochemistry; Rigshospitalet; Copenhagen Denmark
| | - N. Ørtenblad
- Department of Sports Science and Clinical Biomechanics; SDU Muscle Research Cluster; University of Southern Denmark; Odense Denmark
- Department of Health Sciences; Swedish Winter Sports Research Centre; Mid Sweden University; Östersund Sweden
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45
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Lamboley CR, Wyckelsma VL, Dutka TL, McKenna MJ, Murphy RM, Lamb GD. Contractile properties and sarcoplasmic reticulum calcium content in type I and type II skeletal muscle fibres in active aged humans. J Physiol 2015; 593:2499-514. [PMID: 25809942 DOI: 10.1113/jp270179] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Accepted: 03/23/2015] [Indexed: 01/25/2023] Open
Abstract
KEY POINTS Muscle weakness in old age is due in large part to an overall loss of skeletal muscle tissue, but it remains uncertain how much also stems from alterations in the properties of the individual muscle fibres. This study examined the contractile properties and amount of stored intracellular calcium in single muscle fibres of Old (70 ± 4 years) and Young (22 ± 3 years) adults. The maximum level of force production (per unit cross-sectional area) in fast twitch fibres in Old subjects was lower than in Young subjects, and the fibres were also less sensitive to activation by calcium. The amount of calcium stored inside muscle fibres and available to trigger contraction was also lower in both fast- and slow-twitch muscle fibres in the Old subjects. These findings indicate that muscle weakness in old age stems in part from an impaired capacity for force production in the individual muscle fibres. ABSTRACT This study examined the contractile properties and sarcoplasmic reticulum (SR) Ca(2+) content in mechanically skinned vastus lateralis muscle fibres of Old (70 ± 4 years) and Young (22 ± 3 years) humans to investigate whether changes in muscle fibre properties contribute to muscle weakness in old age. In type II fibres of Old subjects, specific force was reduced by ∼17% and Ca(2+) sensitivity was also reduced (pCa50 decreased ∼0.05 pCa units) relative to that in Young. S-Glutathionylation of fast troponin I (TnIf ) markedly increased Ca(2+) sensitivity in type II fibres, but the increase was significantly smaller in Old versus Young (+0.136 and +0.164 pCa unit increases, respectively). Endogenous and maximal SR Ca(2+) content were significantly smaller in both type I and type II fibres in Old subjects. In fibres of Young, the SR could be nearly fully depleted of Ca(2+) by a combined caffeine and low Mg(2+) stimulus, whereas in fibres of Old the amount of non-releasable Ca(2+) was significantly increased (by > 12% of endogenous Ca(2+) content). Western blotting showed an increased proportion of type I fibres in Old subjects, and increased amounts of calsequestrin-2 and calsequestrin-like protein. The findings suggest that muscle weakness in old age is probably attributable in part to (i) an increased proportion of type I fibres, (ii) a reduction in both maximum specific force and Ca(2+) sensitivity in type II fibres, and also a decreased ability of S-glutathionylation of TnIf to counter the fatiguing effects of metabolites on Ca(2+) sensitivity, and (iii) a reduction in the amount of releasable SR Ca(2+) in both fibre types.
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Affiliation(s)
- C R Lamboley
- Institute of Sport, Exercise and Active Living (ISEAL), Victoria University, PO Box 14428, Melbourne, Victoria, 8001, Australia
| | - V L Wyckelsma
- Institute of Sport, Exercise and Active Living (ISEAL), Victoria University, PO Box 14428, Melbourne, Victoria, 8001, Australia.,La Trobe Rural Health School, La Trobe University, Melbourne, Victoria, 3086, Australia
| | - T L Dutka
- School of Life Sciences, La Trobe University, Melbourne, Victoria, 3086, Australia
| | - M J McKenna
- Institute of Sport, Exercise and Active Living (ISEAL), Victoria University, PO Box 14428, Melbourne, Victoria, 8001, Australia
| | - R M Murphy
- School of Molecular Sciences, La Trobe University, Melbourne, Victoria, 3086, Australia
| | - G D Lamb
- School of Life Sciences, La Trobe University, Melbourne, Victoria, 3086, Australia
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46
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Callahan DM, Tourville TW, Miller MS, Hackett SB, Sharma H, Cruickshank NC, Slauterbeck JR, Savage PD, Ades PA, Maughan DW, Beynnon BD, Toth MJ. Chronic disuse and skeletal muscle structure in older adults: sex-specific differences and relationships to contractile function. Am J Physiol Cell Physiol 2015; 308:C932-43. [PMID: 25810256 DOI: 10.1152/ajpcell.00014.2015] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Accepted: 03/24/2015] [Indexed: 11/22/2022]
Abstract
In older adults, we examined the effect of chronic muscle disuse on skeletal muscle structure at the tissue, cellular, organellar, and molecular levels and its relationship to muscle function. Volunteers with advanced-stage knee osteoarthritis (OA, n = 16) were recruited to reflect the effects of chronic lower extremity muscle disuse and compared with recreationally active controls (n = 15) without knee OA but similar in age, sex, and health status. In the OA group, quadriceps muscle and single-fiber cross-sectional area were reduced, with the largest reduction in myosin heavy chain IIA fibers. Myosin heavy chain IIAX fibers were more prevalent in the OA group, and their atrophy was sex-specific: men showed a reduction in cross-sectional area, and women showed no differences. Myofibrillar ultrastructure, myonuclear content, and mitochondrial content and morphology generally did not differ between groups, with the exception of sex-specific adaptations in subsarcolemmal (SS) mitochondria, which were driven by lower values in OA women. SS mitochondrial content was also differently related to cellular and molecular functional parameters by sex: greater SS mitochondrial content was associated with improved contractility in women but reduced function in men. Collectively, these results demonstrate sex-specific structural phenotypes at the cellular and organellar levels with chronic disuse in older adults, with novel associations between energetic and contractile systems.
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Affiliation(s)
- Damien M Callahan
- Department of Medicine, College of Medicine, University of Vermont, Burlington, Vermont
| | - Timothy W Tourville
- Department of Orthopaedics and Rehabilitation, College of Medicine, University of Vermont, Burlington, Vermont
| | - Mark S Miller
- Department of Molecular Physiology and Biophysics, College of Medicine, University of Vermont, Burlington, Vermont; and
| | - Sarah B Hackett
- Department of Medicine, College of Medicine, University of Vermont, Burlington, Vermont
| | - Himani Sharma
- Department of Medicine, College of Medicine, University of Vermont, Burlington, Vermont
| | | | - James R Slauterbeck
- Department of Orthopaedics and Rehabilitation, College of Medicine, University of Vermont, Burlington, Vermont
| | - Patrick D Savage
- Department of Medicine, College of Medicine, University of Vermont, Burlington, Vermont
| | - Philip A Ades
- Department of Medicine, College of Medicine, University of Vermont, Burlington, Vermont
| | - David W Maughan
- Department of Molecular Physiology and Biophysics, College of Medicine, University of Vermont, Burlington, Vermont; and
| | - Bruce D Beynnon
- Department of Orthopaedics and Rehabilitation, College of Medicine, University of Vermont, Burlington, Vermont
| | - Michael J Toth
- Department of Medicine, College of Medicine, University of Vermont, Burlington, Vermont; Department of Molecular Physiology and Biophysics, College of Medicine, University of Vermont, Burlington, Vermont; and
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47
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Kristensen DE, Albers PH, Prats C, Baba O, Birk JB, Wojtaszewski JFP. Human muscle fibre type-specific regulation of AMPK and downstream targets by exercise. J Physiol 2015; 593:2053-69. [PMID: 25640469 DOI: 10.1113/jphysiol.2014.283267] [Citation(s) in RCA: 81] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2014] [Accepted: 01/23/2015] [Indexed: 11/08/2022] Open
Abstract
AMP-activated protein kinase (AMPK) is a regulator of energy homeostasis during exercise. Studies suggest muscle fibre type-specific AMPK expression. However, fibre type-specific regulation of AMPK and downstream targets during exercise has not been demonstrated. We hypothesized that AMPK subunits are expressed in a fibre type-dependent manner and that fibre type-specific activation of AMPK and downstream targets is dependent on exercise intensity. Pools of type I and II fibres were prepared from biopsies of vastus lateralis muscle from healthy men before and after two exercise trials: (1) continuous cycling (CON) for 30 min at 69 ± 1% peak rate of O2 consumption (V̇O2 peak ) or (2) interval cycling (INT) for 30 min with 6 × 1.5 min high-intensity bouts peaking at 95 ± 2% V̇O2 peak . In type I vs. II fibres a higher β1 AMPK (+215%) and lower γ3 AMPK expression (-71%) was found. α1 , α2 , β2 and γ1 AMPK expression was similar between fibre types. In type I vs. II fibres phosphoregulation after CON was similar (AMPK(Thr172) , ACC(Ser221) , TBC1D1(Ser231) and GS(2+2a) ) or lower (TBC1D4(Ser704) ). Following INT, phosphoregulation in type I vs. II fibres was lower (AMPK(Thr172) , TBC1D1(Ser231) , TBC1D4(Ser704) and ACC(Ser221) ) or higher (GS(2+2a) ). Exercise-induced glycogen degradation in type I vs. II fibres was similar (CON) or lower (INT). In conclusion, a differentiated response to exercise of metabolic signalling/effector proteins in human type I and II fibres was evident during interval exercise. This could be important for exercise type-specific adaptations, i.e. insulin sensitivity and mitochondrial density, and highlights the potential for new discoveries when investigating fibre type-specific signalling.
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Affiliation(s)
- Dorte E Kristensen
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, August Krogh Centre, University of Copenhagen, Copenhagen, Denmark
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48
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Miller MS, Bedrin NG, Ades PA, Palmer BM, Toth MJ. Molecular determinants of force production in human skeletal muscle fibers: effects of myosin isoform expression and cross-sectional area. Am J Physiol Cell Physiol 2015; 308:C473-84. [PMID: 25567808 DOI: 10.1152/ajpcell.00158.2014] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Skeletal muscle contractile performance is governed by the properties of its constituent fibers, which are, in turn, determined by the molecular interactions of the myofilament proteins. To define the molecular determinants of contractile function in humans, we measured myofilament mechanics during maximal Ca(2+)-activated and passive isometric conditions in single muscle fibers with homogenous (I and IIA) and mixed (I/IIA and IIA/X) myosin heavy chain (MHC) isoforms from healthy, young adult male (n = 5) and female (n = 7) volunteers. Fibers containing only MHC II isoforms (IIA and IIA/X) produced higher maximal Ca(2+)-activated forces over the range of cross-sectional areas (CSAs) examined than MHC I fibers, resulting in higher (24-42%) specific forces. The number and/or stiffness of the strongly bound myosin-actin cross bridges increased in the higher force-producing MHC II isoforms and, in all isoforms, better predicted force than CSA. In men and women, cross-bridge kinetics, in terms of myosin attachment time and rate of myosin force production, were independent of CSA, although women had faster (7-15%) kinetics. The relative proportion of cross bridges and/or their stiffness was reduced as fiber size increased, causing a decline in specific force. Results from our examination of molecular mechanisms across the range of physiological CSAs explain the variation in specific force among the different fiber types in human skeletal muscle, which may have relevance to understanding how various physiological and pathophysiological conditions modulate single-fiber and whole muscle contractility.
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Affiliation(s)
- Mark S Miller
- Department of Molecular Physiology and Biophysics, College of Medicine, University of Vermont, Burlington, Vermont; Department of Kinesiology, School of Public Health and Health Sciences, University of Massachusetts, Amherst, Massachusetts
| | - Nicholas G Bedrin
- Department of Molecular Physiology and Biophysics, College of Medicine, University of Vermont, Burlington, Vermont
| | - Philip A Ades
- Department of Medicine, College of Medicine, University of Vermont, Burlington, Vermont; and
| | - Bradley M Palmer
- Department of Molecular Physiology and Biophysics, College of Medicine, University of Vermont, Burlington, Vermont
| | - Michael J Toth
- Department of Molecular Physiology and Biophysics, College of Medicine, University of Vermont, Burlington, Vermont; Department of Medicine, College of Medicine, University of Vermont, Burlington, Vermont; and
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49
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Wall BT, Dirks ML, Snijders T, Stephens FB, Senden JM, Verscheijden ML, van Loon LJ. Short-term muscle disuse atrophy is not associated with increased intramuscular lipid deposition or a decline in the maximal activity of key mitochondrial enzymes in young and older males. Exp Gerontol 2015; 61:76-83. [DOI: 10.1016/j.exger.2014.11.019] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2014] [Revised: 11/11/2014] [Accepted: 11/27/2014] [Indexed: 01/06/2023]
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50
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Skeletal muscle work efficiency with age: the role of non-contractile processes. Clin Sci (Lond) 2014; 128:213-23. [PMID: 25134525 DOI: 10.1042/cs20140274] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Although skeletal muscle work efficiency probably plays a key role in limiting mobility of the elderly, the physiological mechanisms responsible for this diminished function remain incompletely understood. Thus, in the quadriceps of young (n=9) and old (n=10) subjects, we measured the cost of muscle contraction (ATP cost) with 31P-magnetic resonance spectroscopy (31P-MRS) during (i) maximal intermittent contractions to elicit a metabolic demand from both cross-bridge cycling and ion pumping and (ii) a continuous maximal contraction to predominantly tax cross-bridge cycling. The ATP cost of the intermittent contractions was significantly greater in the old (0.30±0.22 mM·min-1·N·m-1) compared with the young (0.13±0.03 mM·min-1·N·m-1, P<0.05). In contrast, at the end of the continuous contraction protocol, the ATP cost in the old (0.10±0.07 mM·min-1·N·m-1) was not different from the young (0.06±0.02 mM·min-1·N·m-1, P=0.2). In addition, the ATP cost of the intermittent contractions correlated significantly with the single leg peak power of the knee-extensors assessed during incremental dynamic exercise (r=-0.55; P<0.05). Overall, this study reveals an age-related increase in the ATP cost of contraction, probably mediated by an excessive energy demand from ion pumping, which probably contributes to both the decline in muscle efficiency and functional capacity associated with aging.
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