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Willis CRG, Gallagher IJ, Wilkinson DJ, Brook MS, Bass JJ, Phillips BE, Smith K, Etheridge T, Stokes T, McGlory C, Gorissen SHM, Szewczyk NJ, Phillips SM, Atherton PJ. Transcriptomic links to muscle mass loss and declines in cumulative muscle protein synthesis during short-term disuse in healthy younger humans. FASEB J 2021; 35:e21830. [PMID: 34342902 DOI: 10.1096/fj.202100276rr] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 07/05/2021] [Accepted: 07/19/2021] [Indexed: 12/13/2022]
Abstract
Muscle disuse leads to a rapid decline in muscle mass, with reduced muscle protein synthesis (MPS) considered the primary physiological mechanism. Here, we employed a systems biology approach to uncover molecular networks and key molecular candidates that quantitatively link to the degree of muscle atrophy and/or extent of decline in MPS during short-term disuse in humans. After consuming a bolus dose of deuterium oxide (D2 O; 3 mL.kg-1 ), eight healthy males (22 ± 2 years) underwent 4 days of unilateral lower-limb immobilization. Bilateral muscle biopsies were obtained post-intervention for RNA sequencing and D2 O-derived measurement of MPS, with thigh lean mass quantified using dual-energy X-ray absorptiometry. Application of weighted gene co-expression network analysis identified 15 distinct gene clusters ("modules") with an expression profile regulated by disuse and/or quantitatively connected to disuse-induced muscle mass or MPS changes. Module scans for candidate targets established an experimentally tractable set of candidate regulatory molecules (242 hub genes, 31 transcriptional regulators) associated with disuse-induced maladaptation, many themselves potently tied to disuse-induced reductions in muscle mass and/or MPS and, therefore, strong physiologically relevant candidates. Notably, we implicate a putative role for muscle protein breakdown-related molecular networks in impairing MPS during short-term disuse, and further establish DEPTOR (a potent mTOR inhibitor) as a critical mechanistic candidate of disuse driven MPS suppression in humans. Overall, these findings offer a strong benchmark for accelerating mechanistic understanding of short-term muscle disuse atrophy that may help expedite development of therapeutic interventions.
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Affiliation(s)
- Craig R G Willis
- Department of Sport and Health Sciences, College of Life and Environmental Sciences, University of Exeter, Exeter, UK
| | - Iain J Gallagher
- Faculty of Health Sciences and Sport, University of Stirling, Stirling, UK
| | - Daniel J Wilkinson
- MRC-Versus Arthritis Centre for Musculoskeletal Ageing Research and National Institute of Health Research, Nottingham Biomedical Research Centre, Royal Derby Hospital Centre, School of Medicine, University of Nottingham, Derby, UK
| | - Matthew S Brook
- MRC-Versus Arthritis Centre for Musculoskeletal Ageing Research and National Institute of Health Research, Nottingham Biomedical Research Centre, Royal Derby Hospital Centre, School of Medicine, University of Nottingham, Derby, UK
| | - Joseph J Bass
- MRC-Versus Arthritis Centre for Musculoskeletal Ageing Research and National Institute of Health Research, Nottingham Biomedical Research Centre, Royal Derby Hospital Centre, School of Medicine, University of Nottingham, Derby, UK
| | - Bethan E Phillips
- MRC-Versus Arthritis Centre for Musculoskeletal Ageing Research and National Institute of Health Research, Nottingham Biomedical Research Centre, Royal Derby Hospital Centre, School of Medicine, University of Nottingham, Derby, UK
| | - Kenneth Smith
- MRC-Versus Arthritis Centre for Musculoskeletal Ageing Research and National Institute of Health Research, Nottingham Biomedical Research Centre, Royal Derby Hospital Centre, School of Medicine, University of Nottingham, Derby, UK
| | - Timothy Etheridge
- Department of Sport and Health Sciences, College of Life and Environmental Sciences, University of Exeter, Exeter, UK
| | - Tanner Stokes
- Department of Kinesiology, McMaster University, Hamilton, ON, Canada
| | - Chris McGlory
- Department of Kinesiology, McMaster University, Hamilton, ON, Canada
| | | | - Nathaniel J Szewczyk
- MRC-Versus Arthritis Centre for Musculoskeletal Ageing Research and National Institute of Health Research, Nottingham Biomedical Research Centre, Royal Derby Hospital Centre, School of Medicine, University of Nottingham, Derby, UK.,Ohio Musculoskeletal and Neurological Institute (OMNI) and Department of Biomedical Sciences, Ohio University, Athens, OH, USA
| | - Stuart M Phillips
- Department of Kinesiology, McMaster University, Hamilton, ON, Canada
| | - Philip J Atherton
- MRC-Versus Arthritis Centre for Musculoskeletal Ageing Research and National Institute of Health Research, Nottingham Biomedical Research Centre, Royal Derby Hospital Centre, School of Medicine, University of Nottingham, Derby, UK
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Eftestøl E, Franchi MV, Kasper S, Flück M. JNK activation in TA and EDL muscle is load-dependent in rats receiving identical excitation patterns. Sci Rep 2021; 11:16405. [PMID: 34385505 PMCID: PMC8361015 DOI: 10.1038/s41598-021-94930-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 07/12/2021] [Indexed: 11/09/2022] Open
Abstract
As the excitation-contraction coupling is inseparable during voluntary exercise, the relative contribution of the mechanical and neural input on hypertrophy-related molecular signalling is still poorly understood. Herein, we use a rat in-vivo strength exercise model with an electrically-induced standardized excitation pattern, previously shown to induce a load-dependent increase in myonuclear number and hypertrophy, to study acute effects of load on molecular signalling. We assessed protein abundance and specific phosphorylation of the four protein kinases FAK, mTOR, p70S6K and JNK after 2, 10 and 28 min of a low- or high-load contraction, in order to assess the effects of load, exercise duration and muscle-type on their response to exercise. Specific phosphorylation of mTOR, p70S6K and JNK was increased after 28 min of exercise under the low- and high-load protocol. Elevated phosphorylation of mTOR and JNK was detectable already after 2 and 10 min of exercise, respectively, but greatest after 28 min of exercise, and JNK phosphorylation was highly load-dependent. The abundance of all four kinases was higher in TA compared to EDL muscle, p70S6K abundance was increased after exercise in a load-independent manner, and FAK and JNK abundance was reduced after 28 min of exercise in both the exercised and control muscles. In conclusion, the current study shows that JNK activation after a single resistance exercise is load-specific, resembling the previously reported degree of myonuclear accrual and muscle hypertrophy with repetition of the exercise stimulus.
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Affiliation(s)
- Einar Eftestøl
- Department of Biosciences, University of Oslo, Kristine Bonnevies hus, Blindernveien 31, 0371, Oslo, Norway.
| | - Martino V Franchi
- Laboratory for Muscle Plasticity, Department of Orthopaedics, University of Zürich, Zurich, Switzerland.,Department of Biomedical Sciences, University of Padova, Padua, Italy
| | - Stephanie Kasper
- Laboratory for Muscle Plasticity, Department of Orthopaedics, University of Zürich, Zurich, Switzerland
| | - Martin Flück
- Laboratory for Muscle Plasticity, Department of Orthopaedics, University of Zürich, Zurich, Switzerland
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Blackwell JEM, Gharahdaghi N, Brook MS, Watanabe S, Boereboom CL, Doleman B, Lund JN, Wilkinson DJ, Smith K, Atherton PJ, Williams JP, Phillips BE. The physiological impact of high-intensity interval training in octogenarians with comorbidities. J Cachexia Sarcopenia Muscle 2021; 12:866-879. [PMID: 34060253 PMCID: PMC8350218 DOI: 10.1002/jcsm.12724] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 04/22/2021] [Accepted: 05/07/2021] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Declines in cardiorespiratory fitness (CRF) and fat-free mass (FFM) with age are linked to mortality, morbidity and poor quality of life. High-intensity interval training (HIIT) has been shown to improve CRF and FFM in many groups, but its efficacy in the very old, in whom comorbidities are present is undefined. We aimed to assess the efficacy of and physiological/metabolic responses to HIIT, in a cohort of octogenarians with comorbidities (e.g. hypertension and osteoarthritis). METHODS Twenty-eight volunteers (18 men, 10 women, 81.2 ± 0.6 years, 27.1 ± 0.6 kg·m-2 ) with American Society of Anaesthesiology (ASA) Grade 2-3 status each completed 4 weeks (12 sessions) HIIT after a control period of equal duration. Before and after each 4 week period, subjects underwent body composition assessments and cardiopulmonary exercise testing. Quadriceps muscle biopsies (m. vastus lateralis) were taken to quantify anabolic signalling, mitochondrial oxidative phosphorylation, and cumulative muscle protein synthesis (MPS) over 4-weeks. RESULTS In comorbid octogenarians, HIIT elicited improvements in CRF (anaerobic threshold: +1.2 ± 0.4 ml·kg-1 ·min-1 , P = 0.001). HIIT also augmented total FFM (47.2 ± 1.4 to 47.6 ± 1.3 kg, P = 0.04), while decreasing total fat mass (24.8 ± 1.3 to 24 ± 1.2 kg, P = 0.0002) and body fat percentage (33.1 ± 1.5 to 32.1 ± 1.4%, P = 0.0008). Mechanistically, mitochondrial oxidative phosphorylation capacity increased after HIIT (i.e. citrate synthase activity: 52.4 ± 4 to 67.9 ± 5.1 nmol·min-1 ·mg-1 , P = 0.005; membrane protein complexes (C): C-II, 1.4-fold increase, P = 0.002; C-III, 1.2-fold increase, P = 0.03), as did rates of MPS (1.3 ± 0.1 to 1.5 ± 0.1%·day-1 , P = 0.03). The increase in MPS was supported by up-regulated phosphorylation of anabolic signalling proteins (e.g. AKT, p70S6K, and 4E-BP1; all P < 0.05). There were no changes in any of these parameters during the control period. No adverse events were reported throughout the study. CONCLUSIONS The HIIT enhances skeletal muscle mass and CRF in octogenarians with disease, with up-regulation of MPS and mitochondrial capacity likely underlying these improvements. HIIT can be safely delivered to octogenarians with disease and is an effective, time-efficient intervention to improve muscle mass and physical function in a short time frame.
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Affiliation(s)
- James E M Blackwell
- MRC-Versus Arthritis Centre for Musculoskeletal Ageing Research, Royal Derby Hospital Centre, University of Nottingham, Derby, UK.,Department of Surgery & Anaesthetics, Royal Derby Hospital, Derby, UK
| | - Nima Gharahdaghi
- MRC-Versus Arthritis Centre for Musculoskeletal Ageing Research, Royal Derby Hospital Centre, University of Nottingham, Derby, UK.,National Institute of Health Research (NIHR), Nottingham Biomedical Research Centre (BRC), Nottingham, UK
| | - Matthew S Brook
- MRC-Versus Arthritis Centre for Musculoskeletal Ageing Research, Royal Derby Hospital Centre, University of Nottingham, Derby, UK.,National Institute of Health Research (NIHR), Nottingham Biomedical Research Centre (BRC), Nottingham, UK
| | - Shinya Watanabe
- MRC-Versus Arthritis Centre for Musculoskeletal Ageing Research, Royal Derby Hospital Centre, University of Nottingham, Derby, UK
| | - Catherine L Boereboom
- MRC-Versus Arthritis Centre for Musculoskeletal Ageing Research, Royal Derby Hospital Centre, University of Nottingham, Derby, UK
| | - Brett Doleman
- Department of Surgery & Anaesthetics, Royal Derby Hospital, Derby, UK
| | - Jonathan N Lund
- MRC-Versus Arthritis Centre for Musculoskeletal Ageing Research, Royal Derby Hospital Centre, University of Nottingham, Derby, UK.,Department of Surgery & Anaesthetics, Royal Derby Hospital, Derby, UK
| | - Daniel J Wilkinson
- MRC-Versus Arthritis Centre for Musculoskeletal Ageing Research, Royal Derby Hospital Centre, University of Nottingham, Derby, UK.,National Institute of Health Research (NIHR), Nottingham Biomedical Research Centre (BRC), Nottingham, UK
| | - Kenneth Smith
- MRC-Versus Arthritis Centre for Musculoskeletal Ageing Research, Royal Derby Hospital Centre, University of Nottingham, Derby, UK.,National Institute of Health Research (NIHR), Nottingham Biomedical Research Centre (BRC), Nottingham, UK
| | - Philip J Atherton
- MRC-Versus Arthritis Centre for Musculoskeletal Ageing Research, Royal Derby Hospital Centre, University of Nottingham, Derby, UK.,National Institute of Health Research (NIHR), Nottingham Biomedical Research Centre (BRC), Nottingham, UK
| | - John P Williams
- MRC-Versus Arthritis Centre for Musculoskeletal Ageing Research, Royal Derby Hospital Centre, University of Nottingham, Derby, UK.,Department of Surgery & Anaesthetics, Royal Derby Hospital, Derby, UK
| | - Bethan E Phillips
- MRC-Versus Arthritis Centre for Musculoskeletal Ageing Research, Royal Derby Hospital Centre, University of Nottingham, Derby, UK.,National Institute of Health Research (NIHR), Nottingham Biomedical Research Centre (BRC), Nottingham, UK
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Figueiredo VC, McCarthy JJ. Targeting cancer via ribosome biogenesis: the cachexia perspective. Cell Mol Life Sci 2021; 78:5775-5787. [PMID: 34196731 PMCID: PMC11072391 DOI: 10.1007/s00018-021-03888-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 06/03/2021] [Accepted: 06/18/2021] [Indexed: 12/14/2022]
Abstract
Cancer cachexia afflicts many advanced cancer patients with many progressing to death. While there have been many advancements in understanding the molecular mechanisms that contribute to the development of cancer cachexia, substantial gaps still exist. Chemotherapy drugs often target ribosome biogenesis to slow or blunt tumor cell growth and proliferation. Some of the most frequent side-effects of chemotherapy are loss of skeletal muscle mass, muscular strength and an increase in fatigue. Given that ribosome biogenesis has emerged as a main mechanism regulating muscle hypertrophy, and more recently, also implicated in muscle atrophy, we propose that some chemotherapy drugs can cause further muscle wasting via its effect on skeletal muscle cells. Many chemotherapy drugs, including the most prescribed drugs such as doxorubicin and cisplatin, affect ribosomal DNA transcription, or other pathways related to ribosome biogenesis. Furthermore, middle-aged and older individuals are the most affected population with cancer, and advanced cancer patients often show reduced levels of physical inactivity. Thus, aging and inactivity can themselves affect muscle ribosome biogenesis, which can further worsen the effect of chemotherapy on skeletal muscle ribosome biogenesis and, ultimately, muscle mass and function. We propose that chemotherapy can accelerate the onset or worsen cancer cachexia via its inhibitory effects on skeletal muscle ribosome biogenesis. We end our review by providing recommendations that could be used to ameliorate the negative effects of chemotherapy on skeletal muscle ribosome biogenesis.
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Affiliation(s)
- Vandré Casagrande Figueiredo
- College of Health Sciences, University of Kentucky, Lexington, KY, USA.
- Center for Muscle Biology, University of Kentucky, Lexington, KY, USA.
| | - John J McCarthy
- Department of Physiology, College of Medicine, University of Kentucky, Lexington, KY, USA
- Center for Muscle Biology, University of Kentucky, Lexington, KY, USA
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55
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Shur NF, Creedon L, Skirrow S, Atherton PJ, MacDonald IA, Lund J, Greenhaff PL. Age-related changes in muscle architecture and metabolism in humans: The likely contribution of physical inactivity to age-related functional decline. Ageing Res Rev 2021; 68:101344. [PMID: 33872778 PMCID: PMC8140403 DOI: 10.1016/j.arr.2021.101344] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2020] [Revised: 03/15/2021] [Accepted: 04/13/2021] [Indexed: 12/21/2022]
Abstract
In the United Kingdom (UK), it is projected that by 2035 people aged >65 years will make up 23 % of the population, with those aged >85 years accounting for 5% of the total population. Ageing is associated with progressive changes in muscle metabolism and a decline in functional capacity, leading to a loss of independence. Muscle metabolic changes associated with ageing have been linked to alterations in muscle architecture and declines in muscle mass and insulin sensitivity. However, the biological features often attributed to muscle ageing are also seen in controlled studies of physical inactivity (e.g. reduced step-count and bed-rest), and it is currently unclear how many of these ageing features are due to ageing per se or sedentarism. This is particularly relevant at a time of home confinements reducing physical activity levels during the Covid-19 pandemic. Current knowledge gaps include the relative contribution that physical inactivity plays in the development of many of the negative features associated with muscle decline in older age. Similarly, data demonstrating positive effects of government recommended physical activity guidelines on muscle health are largely non-existent. It is imperative therefore that research examining interactions between ageing, physical activity and muscle mass and metabolic health is prioritised so that it can inform on the "normal" muscle ageing process and on strategies for improving health span and well-being. This review will focus on important changes in muscle architecture and metabolism that accompany ageing and highlight the likely contribution of physical inactivity to these changes.
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Affiliation(s)
- N F Shur
- Versus Arthritis Centre for Sport, Exercise and Osteoarthritis, The University of Nottingham, UK; National Institute for Health Research (NIHR) Nottingham Biomedical Research Centre, UK; School of Life Sciences, University of Nottingham Medical School, Queen's Medical Centre, Nottingham NG7 2UH, UK
| | - L Creedon
- MRC/Versus Arthritis Centre for Musculoskeletal Ageing Research, UK; School of Life Sciences, University of Nottingham Medical School, Queen's Medical Centre, Nottingham NG7 2UH, UK
| | - S Skirrow
- MRC/Versus Arthritis Centre for Musculoskeletal Ageing Research, UK; School of Life Sciences, University of Nottingham Medical School, Queen's Medical Centre, Nottingham NG7 2UH, UK
| | - P J Atherton
- MRC/Versus Arthritis Centre for Musculoskeletal Ageing Research, UK; National Institute for Health Research (NIHR) Nottingham Biomedical Research Centre, UK; School of Medicine, University of Nottingham Medical School, Royal Derby Hospital, Derby DE22 3DT, UK
| | - I A MacDonald
- MRC/Versus Arthritis Centre for Musculoskeletal Ageing Research, UK; National Institute for Health Research (NIHR) Nottingham Biomedical Research Centre, UK; School of Life Sciences, University of Nottingham Medical School, Queen's Medical Centre, Nottingham NG7 2UH, UK
| | - J Lund
- National Institute for Health Research (NIHR) Nottingham Biomedical Research Centre, UK; School of Medicine, University of Nottingham Medical School, Royal Derby Hospital, Derby DE22 3DT, UK
| | - P L Greenhaff
- MRC/Versus Arthritis Centre for Musculoskeletal Ageing Research, UK; Versus Arthritis Centre for Sport, Exercise and Osteoarthritis, The University of Nottingham, UK; National Institute for Health Research (NIHR) Nottingham Biomedical Research Centre, UK; School of Life Sciences, University of Nottingham Medical School, Queen's Medical Centre, Nottingham NG7 2UH, UK.
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McKendry J, Stokes T, Mcleod JC, Phillips SM. Resistance Exercise, Aging, Disuse, and Muscle Protein Metabolism. Compr Physiol 2021; 11:2249-2278. [PMID: 34190341 DOI: 10.1002/cphy.c200029] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Skeletal muscle is the organ of locomotion, its optimal function is critical for athletic performance, and is also important for health due to its contribution to resting metabolic rate and as a site for glucose uptake and storage. Numerous endogenous and exogenous factors influence muscle mass. Much of what is currently known regarding muscle protein turnover is owed to the development and use of stable isotope tracers. Skeletal muscle mass is determined by the meal- and contraction-induced alterations of muscle protein synthesis and muscle protein breakdown. Increased loading as resistance training is the most potent nonpharmacological strategy by which skeletal muscle mass can be increased. Conversely, aging (sarcopenia) and muscle disuse lead to the development of anabolic resistance and contribute to the loss of skeletal muscle mass. Nascent omics-based technologies have significantly improved our understanding surrounding the regulation of skeletal muscle mass at the gene, transcript, and protein levels. Despite significant advances surrounding the mechanistic intricacies that underpin changes in skeletal muscle mass, these processes are complex, and more work is certainly needed. In this article, we provide an overview of the importance of skeletal muscle, describe the influence that resistance training, aging, and disuse exert on muscle protein turnover and the molecular regulatory processes that contribute to changes in muscle protein abundance. © 2021 American Physiological Society. Compr Physiol 11:2249-2278, 2021.
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Affiliation(s)
- James McKendry
- Exercise Metabolism Research Group, Department of Kinesiology, McMaster University, Hamilton, Ontario, Canada
| | - Tanner Stokes
- Exercise Metabolism Research Group, Department of Kinesiology, McMaster University, Hamilton, Ontario, Canada
| | - Jonathan C Mcleod
- Exercise Metabolism Research Group, Department of Kinesiology, McMaster University, Hamilton, Ontario, Canada
| | - Stuart M Phillips
- Exercise Metabolism Research Group, Department of Kinesiology, McMaster University, Hamilton, Ontario, Canada
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Mølmen KS, Hammarström D, Pedersen K, Lian Lie AC, Steile RB, Nygaard H, Khan Y, Hamarsland H, Koll L, Hanestadhaugen M, Eriksen AL, Grindaker E, Whist JE, Buck D, Ahmad R, Strand TA, Rønnestad BR, Ellefsen S. Vitamin D 3 supplementation does not enhance the effects of resistance training in older adults. J Cachexia Sarcopenia Muscle 2021; 12:599-628. [PMID: 33788419 PMCID: PMC8200443 DOI: 10.1002/jcsm.12688] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Revised: 12/30/2020] [Accepted: 01/26/2021] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Lifestyle therapy with resistance training is a potent measure to counteract age-related loss in muscle strength and mass. Unfortunately, many individuals fail to respond in the expected manner. This phenomenon is particularly common among older adults and those with chronic diseases (e.g. chronic obstructive pulmonary disease, COPD) and may involve endocrine variables such as vitamin D. At present, the effects of vitamin D supplementation on responses to resistance training remain largely unexplored. METHODS Ninety-five male and female participants (healthy, n = 71; COPD, n = 24; age 68 ± 5 years) were randomly assigned to receive either vitamin D3 or placebo supplementation for 28 weeks in a double-blinded manner (latitude 61°N, September-May). Seventy-eight participants completed the RCT, which was initiated by 12 weeks of supplementation-only (two weeks with 10 000 IU/day, followed by 2000 IU/day), followed by 13 weeks of combined supplementation (2000 IU/day) and supervised whole-body resistance training (twice weekly), interspersed with testing and measurements. Outcome measures included multiple assessments of muscle strength (nvariables = 7), endurance performance (n = 6), and muscle mass (n = 3, legs, primary), as well as muscle quality (legs), muscle biology (m. vastus lateralis; muscle fibre characteristics, transcriptome), and health-related variables (e.g. visceral fat mass and blood lipid profile). For main outcome domains such as muscle strength and muscle mass, weighted combined factors were calculated from the range of singular assessments. RESULTS Overall, 13 weeks of resistance training increased muscle strength (13% ± 8%), muscle mass (9% ± 8%), and endurance performance (one-legged, 23% ± 15%; whole-body, 8% ± 7%), assessed as weighted combined factors, and were associated with changes in health variables (e.g. visceral fat, -6% ± 21%; [LDL]serum , -4% ± 14%) and muscle tissue characteristics such as fibre type proportions (e.g. IIX, -3% points), myonuclei per fibre (30% ± 65%), total RNA/rRNA abundances (15%/6-19%), and transcriptome profiles (e.g. 312 differentially expressed genes). Vitamin D3 supplementation did not affect training-associated changes for any of the main outcome domains, despite robust increases in [25(OH)D]serum (∆49% vs. placebo). No conditional effects were observed for COPD vs. healthy or pre-RCT [25(OH)D]serum . In secondary analyses, vitamin D3 affected expression of gene sets involved in vascular functions in muscle tissue and strength gains in participants with high fat mass, which advocates further study. CONCLUSIONS Vitamin D3 supplementation did not affect muscular responses to resistance training in older adults with or without COPD.
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Affiliation(s)
- Knut Sindre Mølmen
- Section for Health and Exercise PhysiologyInland Norway University of Applied SciencesLillehammerNorway
| | - Daniel Hammarström
- Section for Health and Exercise PhysiologyInland Norway University of Applied SciencesLillehammerNorway
| | - Karianne Pedersen
- Section for Health and Exercise PhysiologyInland Norway University of Applied SciencesLillehammerNorway
| | - Anne Cecilie Lian Lie
- Section for Health and Exercise PhysiologyInland Norway University of Applied SciencesLillehammerNorway
| | - Ragnvald B. Steile
- Section for Health and Exercise PhysiologyInland Norway University of Applied SciencesLillehammerNorway
| | - Håvard Nygaard
- Section for Health and Exercise PhysiologyInland Norway University of Applied SciencesLillehammerNorway
| | - Yusuf Khan
- Section for Health and Exercise PhysiologyInland Norway University of Applied SciencesLillehammerNorway
- Department of BiotechnologyInland Norway University of Applied SciencesHamarNorway
| | - Håvard Hamarsland
- Section for Health and Exercise PhysiologyInland Norway University of Applied SciencesLillehammerNorway
| | - Lise Koll
- Innlandet Hospital TrustLillehammerNorway
| | | | | | - Eirik Grindaker
- Section for Health and Exercise PhysiologyInland Norway University of Applied SciencesLillehammerNorway
| | | | - Daniel Buck
- Section for Health and Exercise PhysiologyInland Norway University of Applied SciencesLillehammerNorway
| | - Rafi Ahmad
- Department of BiotechnologyInland Norway University of Applied SciencesHamarNorway
- Institute of Clinical Medicine, Faculty of Health SciencesUiT – The Arctic University of NorwayTromsøNorway
| | - Tor A. Strand
- Innlandet Hospital TrustLillehammerNorway
- Centre for International HealthUniversity of BergenBergenNorway
| | - Bent R. Rønnestad
- Section for Health and Exercise PhysiologyInland Norway University of Applied SciencesLillehammerNorway
| | - Stian Ellefsen
- Section for Health and Exercise PhysiologyInland Norway University of Applied SciencesLillehammerNorway
- Innlandet Hospital TrustLillehammerNorway
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Deane CS, Willis CRG, Phillips BE, Atherton PJ, Harries LW, Ames RM, Szewczyk NJ, Etheridge T. Transcriptomic meta-analysis of disuse muscle atrophy vs. resistance exercise-induced hypertrophy in young and older humans. J Cachexia Sarcopenia Muscle 2021; 12:629-645. [PMID: 33951310 PMCID: PMC8200445 DOI: 10.1002/jcsm.12706] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Revised: 02/26/2021] [Accepted: 03/29/2021] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Skeletal muscle atrophy manifests across numerous diseases; however, the extent of similarities/differences in causal mechanisms between atrophying conditions in unclear. Ageing and disuse represent two of the most prevalent and costly atrophic conditions, with resistance exercise training (RET) being the most effective lifestyle countermeasure. We employed gene-level and network-level meta-analyses to contrast transcriptomic signatures of disuse and RET, plus young and older RET to establish a consensus on the molecular features of, and therapeutic targets against, muscle atrophy in conditions of high socio-economic relevance. METHODS Integrated gene-level and network-level meta-analysis was performed on publicly available microarray data sets generated from young (18-35 years) m. vastus lateralis muscle subjected to disuse (unilateral limb immobilization or bed rest) lasting ≥7 days or RET lasting ≥3 weeks, and resistance-trained older (≥60 years) muscle. RESULTS Disuse and RET displayed predominantly separate transcriptional responses, and transcripts altered across conditions were mostly unidirectional. However, disuse and RET induced directly inverted expression profiles for mitochondrial function and translation regulation genes, with COX4I1, ENDOG, GOT2, MRPL12, and NDUFV2, the central hub components of altered mitochondrial networks, and ZMYND11, a hub gene of altered translation regulation. A substantial number of genes (n = 140) up-regulated post-RET in younger muscle were not similarly up-regulated in older muscle, with young muscle displaying a more pronounced extracellular matrix (ECM) and immune/inflammatory gene expression response. Both young and older muscle exhibited similar RET-induced ubiquitination/RNA processing gene signatures with associated PWP1, PSMB1, and RAF1 hub genes. CONCLUSIONS Despite limited opposing gene profiles, transcriptional signatures of disuse are not simply the converse of RET. Thus, the mechanisms of unloading cannot be derived from studying muscle loading alone and provides a molecular basis for understanding why RET fails to target all transcriptional features of disuse. Loss of RET-induced ECM mechanotransduction and inflammatory profiles might also contribute to suboptimal ageing muscle adaptations to RET. Disuse and age-dependent molecular candidates further establish a framework for understanding and treating disuse/ageing atrophy.
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Affiliation(s)
- Colleen S Deane
- Department of Sport and Health Sciences, College of Life and Environmental Sciences, University of Exeter, St. Luke's Campus, Exeter, UK.,Living Systems Institute, University of Exeter, Exeter, UK
| | - Craig R G Willis
- Department of Sport and Health Sciences, College of Life and Environmental Sciences, University of Exeter, St. Luke's Campus, Exeter, UK
| | - Bethan E Phillips
- MRC-ARUK Centre for Musculoskeletal Ageing Research and National Institute of Health Research, Biomedical Research Centre, Division of Medical Sciences and Graduate Entry Medicine, Royal Derby Hospital Centre, School of Medicine, University of Nottingham, Derby, UK
| | - Philip J Atherton
- MRC-ARUK Centre for Musculoskeletal Ageing Research and National Institute of Health Research, Biomedical Research Centre, Division of Medical Sciences and Graduate Entry Medicine, Royal Derby Hospital Centre, School of Medicine, University of Nottingham, Derby, UK
| | - Lorna W Harries
- RNA-Mediated Mechanisms of Disease Group, Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, University of Exeter, Exeter, UK
| | - Ryan M Ames
- Living Systems Institute, University of Exeter, Exeter, UK
| | - Nathaniel J Szewczyk
- MRC-ARUK Centre for Musculoskeletal Ageing Research and National Institute of Health Research, Biomedical Research Centre, Division of Medical Sciences and Graduate Entry Medicine, Royal Derby Hospital Centre, School of Medicine, University of Nottingham, Derby, UK.,Ohio Musculoskeletal and Neurological Institute & Department of Biomedical Sciences, Ohio University, Athens, OH, USA
| | - Timothy Etheridge
- Department of Sport and Health Sciences, College of Life and Environmental Sciences, University of Exeter, St. Luke's Campus, Exeter, UK
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Paulussen KJM, McKenna CF, Beals JW, Wilund KR, Salvador AF, Burd NA. Anabolic Resistance of Muscle Protein Turnover Comes in Various Shapes and Sizes. Front Nutr 2021; 8:615849. [PMID: 34026802 PMCID: PMC8131552 DOI: 10.3389/fnut.2021.615849] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2020] [Accepted: 03/01/2021] [Indexed: 12/18/2022] Open
Abstract
Anabolic resistance is defined by a blunted stimulation of muscle protein synthesis rates (MPS) to common anabolic stimuli in skeletal muscle tissue such as dietary protein and exercise. Generally, MPS is the target of most exercise and feeding interventions as muscle protein breakdown rates seem to be less responsive to these stimuli. Ultimately, the blunted responsiveness of MPS to dietary protein and exercise underpins the loss of the amount and quality of skeletal muscle mass leading to decrements in physical performance in these populations. The increase of both habitual physical activity (including structured exercise that targets general fitness characteristics) and protein dense food ingestion are frontline strategies utilized to support muscle mass, performance, and health. In this paper, we discuss anabolic resistance as a common denominator underpinning muscle mass loss with aging, obesity, and other disease states. Namely, we discuss the fact that anabolic resistance exists as a dimmer switch, capable of varying from higher to lower levels of resistance, to the main anabolic stimuli of feeding and exercise depending on the population. Moreover, we review the evidence on whether increased physical activity and targeted exercise can be leveraged to restore the sensitivity of skeletal muscle tissue to dietary amino acids regardless of the population.
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Affiliation(s)
- Kevin J. M. Paulussen
- Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Urbana, IL, United States
| | - Colleen F. McKenna
- Division of Nutritional Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, United States
| | - Joseph W. Beals
- Center for Human Nutrition, Washington University School of Medicine, St. Louis, MO, United States
| | - Kenneth R. Wilund
- Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Urbana, IL, United States
- Division of Nutritional Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, United States
| | - Amadeo F. Salvador
- Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Urbana, IL, United States
| | - Nicholas A. Burd
- Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Urbana, IL, United States
- Division of Nutritional Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, United States
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60
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Molecular Transducers of Human Skeletal Muscle Remodeling under Different Loading States. Cell Rep 2021; 32:107980. [PMID: 32755574 PMCID: PMC7408494 DOI: 10.1016/j.celrep.2020.107980] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Revised: 02/27/2020] [Accepted: 07/09/2020] [Indexed: 12/11/2022] Open
Abstract
Loading of skeletal muscle changes the tissue phenotype reflecting altered metabolic and functional demands. In humans, heterogeneous adaptation to loading complicates the identification of the underpinning molecular regulators. A within-person differential loading and analysis strategy reduces heterogeneity for changes in muscle mass by ∼40% and uses a genome-wide transcriptome method that models each mRNA from coding exons and 3' and 5' untranslated regions (UTRs). Our strategy detects ∼3-4 times more regulated genes than similarly sized studies, including substantial UTR-selective regulation undetected by other methods. We discover a core of 141 genes correlated to muscle growth, which we validate from newly analyzed independent samples (n = 100). Further validating these identified genes via RNAi in primary muscle cells, we demonstrate that members of the core genes were regulators of protein synthesis. Using proteome-constrained networks and pathway analysis reveals notable relationships with the molecular characteristics of human muscle aging and insulin sensitivity, as well as potential drug therapies.
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Mertz KH, Reitelseder S, Bechshoeft R, Bulow J, Højfeldt G, Jensen M, Schacht SR, Lind MV, Rasmussen MA, Mikkelsen UR, Tetens I, Engelsen SB, Nielsen DS, Jespersen AP, Holm L. The effect of daily protein supplementation, with or without resistance training for 1 year, on muscle size, strength, and function in healthy older adults: A randomized controlled trial. Am J Clin Nutr 2021; 113:790-800. [PMID: 33564844 DOI: 10.1093/ajcn/nqaa372] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Accepted: 11/16/2020] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Protein supplementation alone or combined with resistance training has been proposed to be effective in counteracting age-related losses of muscle mass and strength. OBJECTIVES To investigate the effect of protein supplementation alone or combined with light-intensity or heavy-load resistance exercise on muscle size, strength, and function in older adults. METHODS In a 1-y randomized controlled trial, 208 healthy older adults (>65 y) were randomly assigned to 1 of 5 interventions: 1) carbohydrate supplementation (CARB); 2) collagen protein supplementation (COLL); 3) whey protein supplementation (WHEY); 4) light-intensity resistance training 3-5 times/wk with whey protein supplementation (LITW); and 5) heavy resistance training 3 times weekly with whey protein supplementation (HRTW). Protein supplements contained 20 g protein + 10 g carbohydrate, whereas CARB contained 30 g of carbohydrates. All intervention groups received the supplement twice daily. The primary outcome was change in the quadriceps cross-sectional area (qCSA). Secondary outcomes included measures of lower extremity strength and power, functional capabilities, and body composition. RESULTS There were 184 participants who completed the study. COLL and WHEY did not affect any measured parameter compared to CARB. Compared to WHEY, HRTW improved the qCSA size (between-group difference, +1.68 cm2; 95% CI, +0.41 to +2.95 cm2; P = 0.03), as well as dynamic (+18.4 Nm; 95% CI, +10.1 to +26.6 Nm; P < 10-4) and isometric knee extensor strength (+23.9 Nm; 95% CI, +14.2 to +33.6 Nm; P < 10-5). LITW did not improve the qCSA size, but increased dynamic knee extensor strength compared to WHEY (+13.7 Nm; 95% CI, +5.3 and +22.1 Nm; P = 0.01). CONCLUSIONS Recommending protein supplementation as a stand-alone intervention for healthy older individuals seems ineffective in improving muscle mass and strength. Only HRTW was effective in both preserving muscle mass and increasing strength. Thus, we recommend that future studies investigate strategies to increase long-term compliance to heavy resistance exercise in healthy older adults. This trial was registered at clinicaltrials.gov as NCT02034760.
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Affiliation(s)
- Kenneth H Mertz
- Institute of Sports Medicine, Department of Orthopaedic Surgery M, Bispebjerg Hospital, Copenhagen, Denmark
| | - Søren Reitelseder
- Institute of Sports Medicine, Department of Orthopaedic Surgery M, Bispebjerg Hospital, Copenhagen, Denmark.,Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Rasmus Bechshoeft
- Institute of Sports Medicine, Department of Orthopaedic Surgery M, Bispebjerg Hospital, Copenhagen, Denmark
| | - Jacob Bulow
- Institute of Sports Medicine, Department of Orthopaedic Surgery M, Bispebjerg Hospital, Copenhagen, Denmark
| | - Grith Højfeldt
- Institute of Sports Medicine, Department of Orthopaedic Surgery M, Bispebjerg Hospital, Copenhagen, Denmark
| | - Mikkel Jensen
- Institute of Sports Medicine, Department of Orthopaedic Surgery M, Bispebjerg Hospital, Copenhagen, Denmark
| | - Simon R Schacht
- Vitality Centre for Good Older Lives, Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | - Mads Vendelbo Lind
- Vitality Centre for Good Older Lives, Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | - Morten A Rasmussen
- Department of Food Science, University of Copenhagen, Copenhagen, Denmark
| | | | - Inge Tetens
- Vitality Centre for Good Older Lives, Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | - Søren B Engelsen
- Department of Food Science, University of Copenhagen, Copenhagen, Denmark
| | - Dennis S Nielsen
- Department of Food Science, University of Copenhagen, Copenhagen, Denmark
| | - Astrid P Jespersen
- Copenhagen Center for Health Research in the Humanities, Saxo-Institute, University of Copenhagen, Copenhagen, Denmark
| | - Lars Holm
- Institute of Sports Medicine, Department of Orthopaedic Surgery M, Bispebjerg Hospital, Copenhagen, Denmark.,Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,School of Sport, Exercise, and Rehabilitation Sciences, University of Birmingham, Birmingham, United Kingdom
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62
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Chapple LAS, Dirks ML, Kouw IW. Stable isotope approaches to study muscle mass outcomes in clinical populations. CLINICAL NUTRITION OPEN SCIENCE 2021. [DOI: 10.1016/j.nutos.2021.01.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
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63
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Wilkinson DJ, Brook MS, Smith K. Principles of stable isotope research - with special reference to protein metabolism. CLINICAL NUTRITION OPEN SCIENCE 2021; 36:111-125. [PMID: 33969338 PMCID: PMC8083121 DOI: 10.1016/j.nutos.2021.02.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Accepted: 02/06/2021] [Indexed: 12/13/2022] Open
Abstract
The key to understanding the mechanisms regulating disease stems from the ability to accurately quantify the dynamic nature of the metabolism underlying the physiological and pathological changes occurring as a result of the disease. Stable isotope tracer technologies have been at the forefront of this for almost 80 years now, and through a combination of both intense theoretical and technological development over these decades, it is now possible to utilise stable isotope tracers to investigate the complexities of in vivo human metabolism from a whole body perspective, down to the regulation of sub-nanometer cellular components (i.e organelles, nucleotides and individual proteins). This review therefore aims to highlight; 1) the advances made in these stable isotope tracer approaches - with special reference given to their role in understanding the nutritional regulation of protein metabolism, 2) some considerations required for the appropriate application of these stable isotope techniques to study protein metabolism, 3) and finally how new stable isotopes approaches and instrument/technical developments will help to deliver greater clinical insight in the near future.
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Key Words
- A-V, Arterial Venous
- AA, Amino Acids
- AP(E), Atom percent (excess)
- FBR, Fractional Breakdown Rate
- FSR, Fractional Synthesis Rate
- GC-MS, Gas Chromatography Mass Spectrometry
- LC-MS, Liquid Chromatography Mass Spectrometry
- MPS, Muscle Protein Synthesis
- Muscle
- Protein turnover
- Ra, Rate of Appearance
- Rd, Rate of Disappearance
- Stable isotope tracers
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Affiliation(s)
- Daniel J. Wilkinson
- MRC-Versus Arthritis Centre for Musculoskeletal Ageing Research, NIHR Nottingham BRC, UK
- Division of Health Sciences and Graduate Entry Medicine, School of Medicine, University of Nottingham, Royal Derby Hospital Centre, Derby, UK
| | - Matthew S. Brook
- MRC-Versus Arthritis Centre for Musculoskeletal Ageing Research, NIHR Nottingham BRC, UK
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, Queen's Medical Centre, University of Nottingham, Nottingham, UK
| | - Ken Smith
- MRC-Versus Arthritis Centre for Musculoskeletal Ageing Research, NIHR Nottingham BRC, UK
- Division of Health Sciences and Graduate Entry Medicine, School of Medicine, University of Nottingham, Royal Derby Hospital Centre, Derby, UK
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64
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Solsona R, Pavlin L, Bernardi H, Sanchez AMJ. Molecular Regulation of Skeletal Muscle Growth and Organelle Biosynthesis: Practical Recommendations for Exercise Training. Int J Mol Sci 2021; 22:2741. [PMID: 33800501 PMCID: PMC7962973 DOI: 10.3390/ijms22052741] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 03/04/2021] [Accepted: 03/04/2021] [Indexed: 12/18/2022] Open
Abstract
The regulation of skeletal muscle mass and organelle homeostasis is dependent on the capacity of cells to produce proteins and to recycle cytosolic portions. In this investigation, the mechanisms involved in skeletal muscle mass regulation-especially those associated with proteosynthesis and with the production of new organelles-are presented. Thus, the critical roles of mammalian/mechanistic target of rapamycin complex 1 (mTORC1) pathway and its regulators are reviewed. In addition, the importance of ribosome biogenesis, satellite cells involvement, myonuclear accretion, and some major epigenetic modifications related to protein synthesis are discussed. Furthermore, several studies conducted on the topic of exercise training have recognized the central role of both endurance and resistance exercise to reorganize sarcomeric proteins and to improve the capacity of cells to build efficient organelles. The molecular mechanisms underlying these adaptations to exercise training are presented throughout this review and practical recommendations for exercise prescription are provided. A better understanding of the aforementioned cellular pathways is essential for both healthy and sick people to avoid inefficient prescriptions and to improve muscle function with emergent strategies (e.g., hypoxic training). Finally, current limitations in the literature and further perspectives, notably on epigenetic mechanisms, are provided to encourage additional investigations on this topic.
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Affiliation(s)
- Robert Solsona
- Laboratoire Interdisciplinaire Performance Santé Environnement de Montagne (LIPSEM), Faculty of Sports Sciences, University of Perpignan Via Domitia, UR 4640, 7 Avenue Pierre de Coubertin, 66120 Font-Romeu, France;
| | - Laura Pavlin
- DMEM, University of Montpellier, INRAE UMR866, 2 Place Pierre Viala, 34060 Montpellier, France; (L.P.); (H.B.)
| | - Henri Bernardi
- DMEM, University of Montpellier, INRAE UMR866, 2 Place Pierre Viala, 34060 Montpellier, France; (L.P.); (H.B.)
| | - Anthony MJ Sanchez
- Laboratoire Interdisciplinaire Performance Santé Environnement de Montagne (LIPSEM), Faculty of Sports Sciences, University of Perpignan Via Domitia, UR 4640, 7 Avenue Pierre de Coubertin, 66120 Font-Romeu, France;
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65
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Hunt LC, Schadeberg B, Stover J, Haugen B, Pagala V, Wang YD, Puglise J, Barton ER, Peng J, Demontis F. Antagonistic control of myofiber size and muscle protein quality control by the ubiquitin ligase UBR4 during aging. Nat Commun 2021; 12:1418. [PMID: 33658508 PMCID: PMC7930053 DOI: 10.1038/s41467-021-21738-8] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Accepted: 02/08/2021] [Indexed: 01/31/2023] Open
Abstract
Sarcopenia is a degenerative condition that consists in age-induced atrophy and functional decline of skeletal muscle cells (myofibers). A common hypothesis is that inducing myofiber hypertrophy should also reinstate myofiber contractile function but such model has not been extensively tested. Here, we find that the levels of the ubiquitin ligase UBR4 increase in skeletal muscle with aging, and that UBR4 increases the proteolytic activity of the proteasome. Importantly, muscle-specific UBR4 loss rescues age-associated myofiber atrophy in mice. However, UBR4 loss reduces the muscle specific force and accelerates the decline in muscle protein quality that occurs with aging in mice. Similarly, hypertrophic signaling induced via muscle-specific loss of UBR4/poe and of ESCRT members (HGS/Hrs, STAM, USP8) that degrade ubiquitinated membrane proteins compromises muscle function and shortens lifespan in Drosophila by reducing protein quality control. Altogether, these findings indicate that these ubiquitin ligases antithetically regulate myofiber size and muscle protein quality control.
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Affiliation(s)
- Liam C Hunt
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Bronwen Schadeberg
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Jared Stover
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Benard Haugen
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Vishwajeeth Pagala
- Department of Structural Biology, Center for Proteomics and Metabolomics, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Yong-Dong Wang
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Jason Puglise
- College of Health & Human Performance Applied Physiology & Kinesiology, University of Florida, Gainesville, FL, USA
| | - Elisabeth R Barton
- College of Health & Human Performance Applied Physiology & Kinesiology, University of Florida, Gainesville, FL, USA
| | - Junmin Peng
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN, USA
- Department of Structural Biology, Center for Proteomics and Metabolomics, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Fabio Demontis
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN, USA.
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66
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Allen SL, Quinlan JI, Dhaliwal A, Armstrong MJ, Elsharkawy AM, Greig CA, Lord JM, Lavery GG, Breen L. Sarcopenia in chronic liver disease: mechanisms and countermeasures. Am J Physiol Gastrointest Liver Physiol 2021; 320:G241-G257. [PMID: 33236953 PMCID: PMC8609568 DOI: 10.1152/ajpgi.00373.2020] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Sarcopenia, a condition of low muscle mass, quality, and strength, is commonly found in patients with cirrhosis and is associated with adverse clinical outcomes including reduction in quality of life, increased mortality, and posttransplant complications. In chronic liver disease (CLD), sarcopenia is most commonly defined through the measurement of the skeletal muscle index of the third lumbar spine. A major contributor to sarcopenia in CLD is the imbalance in muscle protein turnover, which likely occurs due to a decrease in muscle protein synthesis and an elevation in muscle protein breakdown. This imbalance is assumed to arise due to several factors including accelerated starvation, hyperammonemia, amino acid deprivation, chronic inflammation, excessive alcohol intake, and physical inactivity. In particular, hyperammonemia is a key mediator of the liver-gut axis and is known to contribute to mitochondrial dysfunction and an increase in myostatin expression. Currently, the use of nutritional interventions such as late-evening snacks, branched-chain amino acid supplementation, and physical activity have been proposed to help the management and treatment of sarcopenia. However, little evidence exists to comprehensively support their use in clinical settings. Several new pharmacological strategies, including myostatin inhibition and the nutraceutical Urolithin A, have recently been proposed to treat age-related sarcopenia and may also be of use in CLD. This review highlights the potential molecular mechanisms contributing to sarcopenia in CLD alongside a discussion of existing and potential new treatment strategies.
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Affiliation(s)
- Sophie L. Allen
- 1School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, United Kingdom,2National Institute for Health Research, Birmingham Biomedical Research Centre, University Hospitals Birmingham NHS Foundation Trust, Birmingham, United Kingdom
| | - Jonathan I. Quinlan
- 1School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, United Kingdom,2National Institute for Health Research, Birmingham Biomedical Research Centre, University Hospitals Birmingham NHS Foundation Trust, Birmingham, United Kingdom
| | - Amritpal Dhaliwal
- 2National Institute for Health Research, Birmingham Biomedical Research Centre, University Hospitals Birmingham NHS Foundation Trust, Birmingham, United Kingdom,3Institute of Inflammation and Ageing, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom,4Liver Unit, Queen Elizabeth Hospital Birmingham, Birmingham, United Kingdom
| | - Matthew J. Armstrong
- 2National Institute for Health Research, Birmingham Biomedical Research Centre, University Hospitals Birmingham NHS Foundation Trust, Birmingham, United Kingdom,4Liver Unit, Queen Elizabeth Hospital Birmingham, Birmingham, United Kingdom
| | - Ahmed M. Elsharkawy
- 2National Institute for Health Research, Birmingham Biomedical Research Centre, University Hospitals Birmingham NHS Foundation Trust, Birmingham, United Kingdom,3Institute of Inflammation and Ageing, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom,4Liver Unit, Queen Elizabeth Hospital Birmingham, Birmingham, United Kingdom
| | - Carolyn A. Greig
- 1School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, United Kingdom,2National Institute for Health Research, Birmingham Biomedical Research Centre, University Hospitals Birmingham NHS Foundation Trust, Birmingham, United Kingdom,5MRC-Versus Arthritis Centre for Musculoskeletal Ageing Research, University of Birmingham, Birmingham, United Kingdom
| | - Janet M. Lord
- 2National Institute for Health Research, Birmingham Biomedical Research Centre, University Hospitals Birmingham NHS Foundation Trust, Birmingham, United Kingdom,3Institute of Inflammation and Ageing, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom,5MRC-Versus Arthritis Centre for Musculoskeletal Ageing Research, University of Birmingham, Birmingham, United Kingdom
| | - Gareth G. Lavery
- 2National Institute for Health Research, Birmingham Biomedical Research Centre, University Hospitals Birmingham NHS Foundation Trust, Birmingham, United Kingdom,6Institute of Metabolism and Systems Research, University of Birmingham, Birmingham, United Kingdom,7Centre for Endocrinology, Diabetes and Metabolism, Birmingham Health Partner, Birmingham, United Kingdom
| | - Leigh Breen
- 1School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, United Kingdom,2National Institute for Health Research, Birmingham Biomedical Research Centre, University Hospitals Birmingham NHS Foundation Trust, Birmingham, United Kingdom,5MRC-Versus Arthritis Centre for Musculoskeletal Ageing Research, University of Birmingham, Birmingham, United Kingdom
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67
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Daily Myofibrillar Protein Synthesis Rates in Response to Low- and High-Frequency Resistance Exercise Training in Healthy, Young Men. Int J Sport Nutr Exerc Metab 2021; 31:209-216. [PMID: 33601335 DOI: 10.1123/ijsnem.2020-0274] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 11/21/2020] [Accepted: 11/21/2020] [Indexed: 11/18/2022]
Abstract
The impact of resistance exercise frequency on muscle protein synthesis rates remains unknown. The aim of this study was to compare daily myofibrillar protein synthesis rates over a 7-day period of low-frequency (LF) versus high-frequency (HF) resistance exercise training. Nine young men (21 ± 2 years) completed a 7-day period of habitual physical activity (BASAL). This was followed by a 7-day exercise period of volume-matched, LF (10 × 10 repetitions at 70% one-repetition maximum, once per week) or HF (2 × 10 repetitions at ∼70% one-repetition maximum, five times per week) resistance exercise training. The participants had one leg randomly allocated to LF and the other to HF. Skeletal muscle biopsies and daily saliva samples were collected to determine myofibrillar protein synthesis rates using 2H2O, with intracellular signaling determined using Western blotting. The myofibrillar protein synthesis rates did not differ between the LF (1.46 ± 0.26%/day) and HF (1.48 ± 0.33%/day) conditions over the 7-day exercise training period (p > .05). There were no significant differences between the LF and HF conditions over the first 2 days (1.45 ± 0.41%/day vs. 1.25 ± 0.46%/day) or last 5 days (1.47 ± 0.30%/day vs. 1.50 ± 0.41%/day) of the exercise training period (p > .05). Daily myofibrillar protein synthesis rates were not different from BASAL at any time point during LF or HF (p > .05). The phosphorylation status and total protein content of selected proteins implicated in skeletal muscle ribosomal biogenesis were not different between conditions (p > .05). Under the conditions of the present study, resistance exercise training frequency did not modulate daily myofibrillar protein synthesis rates in young men.
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68
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Lees MJ, Nolan D, Amigo-Benavent M, Raleigh CJ, Khatib N, Harnedy-Rothwell P, FitzGerald RJ, Egan B, Carson BP. A Fish-Derived Protein Hydrolysate Induces Postprandial Aminoacidaemia and Skeletal Muscle Anabolism in an In Vitro Cell Model Using Ex Vivo Human Serum. Nutrients 2021; 13:nu13020647. [PMID: 33671235 PMCID: PMC7922518 DOI: 10.3390/nu13020647] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 02/09/2021] [Accepted: 02/12/2021] [Indexed: 12/19/2022] Open
Abstract
Fish-derived proteins, particularly fish protein hydrolysates (FPH), offer potential as high-quality sources of dietary protein, whilst enhancing economic and environmental sustainability. This study investigated the impact of a blue whiting-derived protein hydrolysate (BWPH) on aminoacidaemia in vivo and skeletal muscle anabolism in vitro compared with whey protein isolate (WPI) and an isonitrogenous, non-essential amino acid (NEAA) control (0.33 g·kg−1·body mass−1) in an ex vivo, in vitro experimental design. Blood was obtained from seven healthy older adults (two males, five females; age: 72 ± 5 years, body mass index: 24.9 ± 1.6 kg·m2) in three separate trials in a randomised, counterbalanced, double-blind design. C2C12 myotubes were treated with ex vivo human serum-conditioned media (20%) for 4 h. Anabolic signalling (phosphorylation of mTOR, p70S6K, and 4E-BP1) and puromycin incorporation were determined by immunoblotting. Although BWPH and WPI both induced postprandial essential aminoacidaemia in older adults above the NEAA control, peak and area under the curve (AUC) leucine and essential amino acids were more pronounced following WPI ingestion. Insulin was elevated above baseline in WPI and BWPH only, a finding reinforced by higher peak and AUC values compared with NEAA. Muscle protein synthesis, as measured by puromycin incorporation, was greater after incubation with WPI-fed serum compared with fasted serum (P = 0.042), and delta change was greater in WPI (P = 0.028) and BWPH (P = 0.030) compared with NEAA. Myotube hypertrophy was greater in WPI and BWPH compared with NEAA (both P = 0.045), but was similar between bioactive conditions (P = 0.853). Taken together, these preliminary findings demonstrate the anabolic potential of BWPH in vivo and ex vivo, thus providing justification for larger studies in older adults using gold-standard measures of acute and chronic MPS in vivo.
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Affiliation(s)
- Matthew J. Lees
- Department of Physical Education and Sport Sciences, Faculty of Education and Health Sciences, University of Limerick, V94 T9PX Limerick, Ireland; (M.J.L.); (C.J.R.)
| | - David Nolan
- School of Health and Human Performance, Dublin City University, D09 V209 Dublin, Ireland; (D.N.); (B.E.)
| | - Miryam Amigo-Benavent
- Health Research Institute, University of Limerick, V94 T9PX Limerick, Ireland;
- Department of Biological Sciences, University of Limerick, V94 T9PX Limerick, Ireland; (N.K.); (P.H.-R.); (R.J.F.)
| | - Conor J. Raleigh
- Department of Physical Education and Sport Sciences, Faculty of Education and Health Sciences, University of Limerick, V94 T9PX Limerick, Ireland; (M.J.L.); (C.J.R.)
| | - Neda Khatib
- Department of Biological Sciences, University of Limerick, V94 T9PX Limerick, Ireland; (N.K.); (P.H.-R.); (R.J.F.)
| | - Pádraigín Harnedy-Rothwell
- Department of Biological Sciences, University of Limerick, V94 T9PX Limerick, Ireland; (N.K.); (P.H.-R.); (R.J.F.)
| | - Richard J. FitzGerald
- Department of Biological Sciences, University of Limerick, V94 T9PX Limerick, Ireland; (N.K.); (P.H.-R.); (R.J.F.)
| | - Brendan Egan
- School of Health and Human Performance, Dublin City University, D09 V209 Dublin, Ireland; (D.N.); (B.E.)
| | - Brian P. Carson
- Department of Physical Education and Sport Sciences, Faculty of Education and Health Sciences, University of Limerick, V94 T9PX Limerick, Ireland; (M.J.L.); (C.J.R.)
- Health Research Institute, University of Limerick, V94 T9PX Limerick, Ireland;
- Correspondence:
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69
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Sarcopenia in Inflammatory Bowel Disease: A Narrative Overview. Nutrients 2021; 13:nu13020656. [PMID: 33671473 PMCID: PMC7922969 DOI: 10.3390/nu13020656] [Citation(s) in RCA: 50] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 02/11/2021] [Accepted: 02/11/2021] [Indexed: 02/06/2023] Open
Abstract
Malnutrition is a common condition encountered in patients with inflammatory bowel disease (IBD) and is often associated with sarcopenia (the reduction of muscle mass and strength) which is an ever-growing consideration in chronic diseases. Recent data suggest the prevalence of sarcopenia is 52% and 37% in Crohn's disease and ulcerative colitis, respectively, however it is challenging to fully appreciate the prevalence of sarcopenia in IBD. Sarcopenia is an important consideration in the management of IBD, including the impact on quality of life, prognostication, and treatment such as surgical interventions, biologics and immunomodulators. There is evolving research in many chronic inflammatory states, such as chronic liver disease and rheumatoid arthritis, whereby interventions have begun to be developed to counteract sarcopenia. The purpose of this review is to evaluate the current literature regarding the impact of sarcopenia in the management of IBD, from mechanistic drivers through to assessment and management.
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Bass JJ, Kazi AA, Deane CS, Nakhuda A, Ashcroft SP, Brook MS, Wilkinson DJ, Phillips BE, Philp A, Tarum J, Kadi F, Andersen D, Garcia AM, Smith K, Gallagher IJ, Szewczyk NJ, Cleasby ME, Atherton PJ. The mechanisms of skeletal muscle atrophy in response to transient knockdown of the vitamin D receptor in vivo. J Physiol 2021; 599:963-979. [PMID: 33258480 PMCID: PMC7986223 DOI: 10.1113/jp280652] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Accepted: 11/25/2020] [Indexed: 12/12/2022] Open
Abstract
KEY POINTS Reduced vitamin D receptor (VDR) expression prompts skeletal muscle atrophy. Atrophy occurs through catabolic processes, namely the induction of autophagy, while anabolism remains unchanged. In response to VDR-knockdown mitochondrial function and related gene-set expression is impaired. In vitro VDR knockdown induces myogenic dysregulation occurring through impaired differentiation. These results highlight the autonomous role the VDR has within skeletal muscle mass regulation. ABSTRACT Vitamin D deficiency is estimated to affect ∼40% of the world's population and has been associated with impaired muscle maintenance. Vitamin D exerts its actions through the vitamin D receptor (VDR), the expression of which was recently confirmed in skeletal muscle, and its down-regulation is linked to reduced muscle mass and functional decline. To identify potential mechanisms underlying muscle atrophy, we studied the impact of VDR knockdown (KD) on mature skeletal muscle in vivo, and myogenic regulation in vitro in C2C12 cells. Male Wistar rats underwent in vivo electrotransfer (IVE) to knock down the VDR in hind-limb tibialis anterior (TA) muscle for 10 days. Comprehensive metabolic and physiological analysis was undertaken to define the influence loss of the VDR on muscle fibre composition, protein synthesis, anabolic and catabolic signalling, mitochondrial phenotype and gene expression. Finally, in vitro lentiviral transfection was used to induce sustained VDR-KD in C2C12 cells to analyse myogenic regulation. Muscle VDR-KD elicited atrophy through a reduction in total protein content, resulting in lower myofibre area. Activation of autophagic processes was observed, with no effect upon muscle protein synthesis or anabolic signalling. Furthermore, RNA-sequencing analysis identified systematic down-regulation of multiple mitochondrial respiration-related protein and genesets. Finally, in vitro VDR-knockdown impaired myogenesis (cell cycling, differentiation and myotube formation). Together, these data indicate a fundamental regulatory role of the VDR in the regulation of myogenesis and muscle mass, whereby it acts to maintain muscle mitochondrial function and limit autophagy.
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Affiliation(s)
- Joseph J. Bass
- MRC/ARUK Centre for Musculoskeletal Ageing Research and National Institute for Health Research (NIHR)Nottingham Biomedical Research Centre (BRC)School of MedicineUniversity of NottinghamNottinghamUK
| | - Abid A. Kazi
- Department of Cellular and Molecular PhysiologyPennsylvania State University College of MedicineHersheyPAUSA
| | - Colleen S. Deane
- Department of Sport and Health SciencesUniversity of ExeterExeterUK
- Living Systems InstituteUniversity of ExeterExeterUK
| | - Asif Nakhuda
- MRC/ARUK Centre for Musculoskeletal Ageing Research and National Institute for Health Research (NIHR)Nottingham Biomedical Research Centre (BRC)School of MedicineUniversity of NottinghamNottinghamUK
| | - Stephen P. Ashcroft
- School of Sport, Exercise and Rehabilitation SciencesUniversity of BirminghamBirminghamUK
| | - Matthew S. Brook
- MRC/ARUK Centre for Musculoskeletal Ageing Research and National Institute for Health Research (NIHR)Nottingham Biomedical Research Centre (BRC)School of MedicineUniversity of NottinghamNottinghamUK
| | - Daniel J. Wilkinson
- MRC/ARUK Centre for Musculoskeletal Ageing Research and National Institute for Health Research (NIHR)Nottingham Biomedical Research Centre (BRC)School of MedicineUniversity of NottinghamNottinghamUK
| | - Bethan E. Phillips
- MRC/ARUK Centre for Musculoskeletal Ageing Research and National Institute for Health Research (NIHR)Nottingham Biomedical Research Centre (BRC)School of MedicineUniversity of NottinghamNottinghamUK
| | - Andrew Philp
- School of Sport, Exercise and Rehabilitation SciencesUniversity of BirminghamBirminghamUK
- Mitochondrial Metabolism & Ageing Laboratory, Diabetes and Metabolism DivisionGarvan Institute of Medical ResearchNew South WalesAustralia
- St Vincent's Medical School, UNSW Medicine, UNSWSydneyAustralia
| | - Janelle Tarum
- School of Health SciencesÖrebro UniversityÖrebroSweden
| | - Fawzi Kadi
- School of Health SciencesÖrebro UniversityÖrebroSweden
| | - Ditte Andersen
- Molecular Physiology of Diabetes LaboratoryDepartment of Comparative Biomedical SciencesRoyal Veterinary CollegeLondonUK
| | - Amadeo Muñoz Garcia
- Institute of Metabolism and Systems ResearchThe University of BirminghamBirminghamUK
- Department of Bioinformatics – BiGCaTNUTRIM School of Nutrition and Metabolism in Translational ResearchMaastricht UniversityMaastrichtThe Netherlands
| | - Ken Smith
- MRC/ARUK Centre for Musculoskeletal Ageing Research and National Institute for Health Research (NIHR)Nottingham Biomedical Research Centre (BRC)School of MedicineUniversity of NottinghamNottinghamUK
| | - Iain J. Gallagher
- Physiology, Exercise and Nutrition Research GroupFaculty of Health Sciences and SportUniversity of StirlingStirlingUK
| | - Nathaniel J. Szewczyk
- MRC/ARUK Centre for Musculoskeletal Ageing Research and National Institute for Health Research (NIHR)Nottingham Biomedical Research Centre (BRC)School of MedicineUniversity of NottinghamNottinghamUK
| | - Mark E. Cleasby
- Molecular Physiology of Diabetes LaboratoryDepartment of Comparative Biomedical SciencesRoyal Veterinary CollegeLondonUK
| | - Philip J Atherton
- MRC/ARUK Centre for Musculoskeletal Ageing Research and National Institute for Health Research (NIHR)Nottingham Biomedical Research Centre (BRC)School of MedicineUniversity of NottinghamNottinghamUK
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A collagen hydrolysate/milk protein-blend stimulates muscle anabolism equivalently to an isoenergetic milk protein-blend containing a greater quantity of essential amino acids in older men. Clin Nutr 2021; 40:4456-4464. [PMID: 33487503 PMCID: PMC8251659 DOI: 10.1016/j.clnu.2021.01.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 10/30/2020] [Accepted: 01/05/2021] [Indexed: 12/25/2022]
Abstract
Background & aims Nutritional composition is key for skeletal muscle maintenance into older age. Yet the acute effects of collagen protein blended with other protein sources, in relation to skeletal muscle anabolism, are ill-defined. We investigated human muscle protein synthesis (MPS) responses to a 20 g blend of collagen protein hydrolysate + milk protein (CP+MP, 125 ml) oral nutritional supplement (ONS) vs. 20 g non-blended milk protein source (MP, 200 ml) ONS, in older adults. Methods Healthy older men (N = 8, 71±1 y, BMI: 27±1 kg·m−2) underwent a randomized trial of 20 g protein, from either a CP+MP blend (Fresubin®3.2 kcal DRINK), or a kcal-matched (higher in essential amino acids (EAA) ONS of MP alone. Vastus lateralis (VL) MPS and plasma AA were determined using stable isotope-tracer mass spectrometry; anabolic signaling was quantified via immuno-blotting in VL biopsies taken at baseline and 2/4 h after ONS feeding. Plasma insulin was measured via enzyme-linked immunosorbent assay (ELISA). Measures were taken at rest, after the feed (FED) and after the feed + exercise (FED-EX) conditions (unilateral leg exercise, 6 × 8, 75% 1-RM). Results MP resulted in a greater increase in plasma leucine (MP mean: 152 ± 6 μM, CP+MP mean: 113 ± 4 μM (Feed P < 0.001) and EAA (MP mean: 917 ± 25 μM, CP+MP mean: 786 ± 15 μM (Feed P < 0.01) than CP+MP. CP + MP increased plasma glycine (peak 385 ± 57 μM (P < 0.05)), proline (peak 323 ± 29 μM (P < 0.01)) and non-essential amino acids (NEAA) (peak 1621 ± 107 μM (P < 0.01)) with MP showing no increase. Plasma insulin increased in both trials (CP+MP: 58 ± 10 mU/mL (P < 0.01), MP: 42 ± 6 mU/mL (P < 0.01), with peak insulin greater with CP+MP vs. MP (P < 0.01). MPS demonstrated equivalent increases in response to CP+MP and MP under both FED (MP: 0.039 ± 0.005%/h to 0.081 ± 0.014%/h (P < 0.05), CP+MP: 0.042 ± 0.004%/h to 0.085 ± 0.007%/h (P < 0.05)) and FED-EX (MP: 0.039 ± 0.005%/h to 0.093 ± 0.013%/h (P < 0.01), CP+MP: 0.042 ± 0.004%/h to 0.105 ± 0.015%/h, (P < 0.01)) conditions. FED muscle p-mTOR fold-change from baseline increased to a greater extent with CP+MP vs. MP (P < 0.05), whilst FED-EX muscle p-eEF2 fold-change from baseline decreased to a greater extent with CP+MP vs. MP (P < 0.05); otherwise anabolic signaling responses were indistinguishable. Conclusion Fresubin®3.2 kcal DRINK, which contains a 20 g mixed blend of CP+MP, resulted in equivalent MPS responses to MP alone. Fresubin® 3.2 Kcal DRINK may provide a suitable alternative to MP for use in older adults and a convenient way to supplement calories and protein to improve patient adherence and mitigate muscle mass loss.
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Gharahdaghi N, Phillips BE, Szewczyk NJ, Smith K, Wilkinson DJ, Atherton PJ. Links Between Testosterone, Oestrogen, and the Growth Hormone/Insulin-Like Growth Factor Axis and Resistance Exercise Muscle Adaptations. Front Physiol 2021; 11:621226. [PMID: 33519525 PMCID: PMC7844366 DOI: 10.3389/fphys.2020.621226] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2020] [Accepted: 12/18/2020] [Indexed: 12/13/2022] Open
Abstract
Maintenance of skeletal muscle mass throughout the life course is key for the regulation of health, with physical activity a critical component of this, in part, due to its influence upon key hormones such as testosterone, estrogen, growth hormone (GH), and insulin-like growth factor (IGF). Despite the importance of these hormones for the regulation of skeletal muscle mass in response to different types of exercise, their interaction with the processes controlling muscle mass remain unclear. This review presents evidence on the importance of these hormones in the regulation of skeletal muscle mass and their responses, and involvement in muscle adaptation to resistance exercise. Highlighting the key role testosterone plays as a primary anabolic hormone in muscle adaptation following exercise training, through its interaction with anabolic signaling pathways and other hormones via the androgen receptor (AR), this review also describes the potential importance of fluctuations in other hormones such as GH and IGF-1 in concert with dietary amino acid availability; and the role of estrogen, under the influence of the menstrual cycle and menopause, being especially important in adaptive exercise responses in women. Finally, the downstream mechanisms by which these hormones impact regulation of muscle protein turnover (synthesis and breakdown), and thus muscle mass are discussed. Advances in our understanding of hormones that impact protein turnover throughout life offers great relevance, not just for athletes, but also for the general and clinical populations alike.
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Affiliation(s)
| | | | | | | | - Daniel J. Wilkinson
- Medical Research Council-Versus Arthritis Centre for Musculoskeletal Ageing Research and Nottingham National Institute for Health Research Nottingham Biomedical Research Centre, School of Medicine, University of Nottingham, Derby, United Kingdom
| | - Philip J. Atherton
- Medical Research Council-Versus Arthritis Centre for Musculoskeletal Ageing Research and Nottingham National Institute for Health Research Nottingham Biomedical Research Centre, School of Medicine, University of Nottingham, Derby, United Kingdom
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Bass JJ, Nakhuda A, Deane CS, Brook MS, Wilkinson DJ, Phillips BE, Philp A, Tarum J, Kadi F, Andersen D, Garcia AM, Smith K, Gallagher IJ, Szewczyk NJ, Cleasby ME, Atherton PJ. Overexpression of the vitamin D receptor (VDR) induces skeletal muscle hypertrophy. Mol Metab 2020; 42:101059. [PMID: 32771696 PMCID: PMC7475200 DOI: 10.1016/j.molmet.2020.101059] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Revised: 07/23/2020] [Accepted: 07/28/2020] [Indexed: 12/30/2022] Open
Abstract
OBJECTIVE The Vitamin D receptor (VDR) has been positively associated with skeletal muscle mass, function and regeneration. Mechanistic studies have focused on the loss of the receptor, with in vivo whole-body knockout models demonstrating reduced myofibre size and function and impaired muscle development. To understand the mechanistic role upregulation of the VDR elicits in muscle mass/health, we studied the impact of VDR over-expression (OE) in vivo before exploring the importance of VDR expression upon muscle hypertrophy in humans. METHODS Wistar rats underwent in vivo electrotransfer (IVE) to overexpress the VDR in the Tibialis anterior (TA) muscle for 10 days, before comprehensive physiological and metabolic profiling to characterise the influence of VDR-OE on muscle protein synthesis (MPS), anabolic signalling and satellite cell activity. Stable isotope tracer (D2O) techniques were used to assess sub-fraction protein synthesis, alongside RNA-Seq analysis. Finally, human participants underwent 20 wks of resistance exercise training, with body composition and transcriptomic analysis. RESULTS Muscle VDR-OE yielded total protein and RNA accretion, manifesting in increased myofibre area, i.e., hypertrophy. The observed increases in MPS were associated with enhanced anabolic signalling, reflecting translational efficiency (e.g., mammalian target of rapamycin (mTOR-signalling), with no effects upon protein breakdown markers being observed. Additionally, RNA-Seq illustrated marked extracellular matrix (ECM) remodelling, while satellite cell content, markers of proliferation and associated cell-cycled related gene-sets were upregulated. Finally, induction of VDR mRNA correlated with muscle hypertrophy in humans following long-term resistance exercise type training. CONCLUSION VDR-OE stimulates muscle hypertrophy ostensibly via heightened protein synthesis, translational efficiency, ribosomal expansion and upregulation of ECM remodelling-related gene-sets. Furthermore, VDR expression is a robust marker of the hypertrophic response to resistance exercise in humans. The VDR is a viable target of muscle maintenance through testable Vitamin D molecules, as active molecules and analogues.
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Affiliation(s)
- Joseph J Bass
- MRC/ARUK Centre for Musculoskeletal Ageing Research and National Institute for Health Research (NIHR), Nottingham Biomedical Research Centre (BRC), School of Medicine, University of Nottingham, DE22 3DT, UK
| | - Asif Nakhuda
- MRC/ARUK Centre for Musculoskeletal Ageing Research and National Institute for Health Research (NIHR), Nottingham Biomedical Research Centre (BRC), School of Medicine, University of Nottingham, DE22 3DT, UK
| | - Colleen S Deane
- Department of Sport and Health Sciences, University of Exeter, EX1 2LU, UK
| | - Matthew S Brook
- MRC/ARUK Centre for Musculoskeletal Ageing Research and National Institute for Health Research (NIHR), Nottingham Biomedical Research Centre (BRC), School of Medicine, University of Nottingham, DE22 3DT, UK
| | - Daniel J Wilkinson
- MRC/ARUK Centre for Musculoskeletal Ageing Research and National Institute for Health Research (NIHR), Nottingham Biomedical Research Centre (BRC), School of Medicine, University of Nottingham, DE22 3DT, UK
| | - Bethan E Phillips
- MRC/ARUK Centre for Musculoskeletal Ageing Research and National Institute for Health Research (NIHR), Nottingham Biomedical Research Centre (BRC), School of Medicine, University of Nottingham, DE22 3DT, UK
| | - Andrew Philp
- Mitochondrial Metabolism and Ageing Laboratory, Diabetes and Metabolism Division, Garvan Institute of Medical Research, NSW, 2010, Australia; School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, B15 2TT, UK
| | - Janelle Tarum
- School of Health Sciences, Örebro University, 70182, Sweden
| | - Fawzi Kadi
- School of Health Sciences, Örebro University, 70182, Sweden
| | - Ditte Andersen
- Molecular Physiology of Diabetes Laboratory, Dept. of Comparative Biomedical Sciences, Royal Veterinary College, NW1 0TU, UK
| | - Amadeo Muñoz Garcia
- Institute of Metabolism and Systems Research, The University of Birmingham, Birmingham, UK; Department of Bioinformatics - BiGCaT, NUTRIM School of Nutrition and Metabolism in Translational Research, Maastricht University, Maastricht, the Netherlands
| | - Ken Smith
- MRC/ARUK Centre for Musculoskeletal Ageing Research and National Institute for Health Research (NIHR), Nottingham Biomedical Research Centre (BRC), School of Medicine, University of Nottingham, DE22 3DT, UK
| | - Iain J Gallagher
- Physiology, Exercise and Nutrition Research Group, Faculty of Health Sciences and Sport, University of Stirling, FK9 4LA, UK
| | - Nathaniel J Szewczyk
- MRC/ARUK Centre for Musculoskeletal Ageing Research and National Institute for Health Research (NIHR), Nottingham Biomedical Research Centre (BRC), School of Medicine, University of Nottingham, DE22 3DT, UK
| | - Mark E Cleasby
- Molecular Physiology of Diabetes Laboratory, Dept. of Comparative Biomedical Sciences, Royal Veterinary College, NW1 0TU, UK
| | - Philip J Atherton
- MRC/ARUK Centre for Musculoskeletal Ageing Research and National Institute for Health Research (NIHR), Nottingham Biomedical Research Centre (BRC), School of Medicine, University of Nottingham, DE22 3DT, UK.
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Musci RV, Walsh MA, Konopka AR, Wolff CA, Peelor FF, Reiser RF, Santangelo KS, Hamilton KL. The Dunkin Hartley Guinea Pig Is a Model of Primary Osteoarthritis That Also Exhibits Early Onset Myofiber Remodeling That Resembles Human Musculoskeletal Aging. Front Physiol 2020; 11:571372. [PMID: 33192568 PMCID: PMC7658338 DOI: 10.3389/fphys.2020.571372] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Accepted: 10/09/2020] [Indexed: 12/11/2022] Open
Abstract
Skeletal muscle dysfunction, articular cartilage degeneration, and bone loss occur essentially in parallel during aging. Mechanisms contributing to this systemic musculoskeletal decline remain incompletely understood, limiting progress toward developing effective therapeutics. Because the progression of human musculoskeletal aging is slow, researchers rely on rodent models to identify mechanisms and test interventions. The Dunkin Hartley guinea pig is an outbred strain that begins developing primary osteoarthritis by 4 months of age with a progression and pathology similar to aging humans. The purpose of this study was to determine if skeletal muscle remodeling during the progression of osteoarthritis in these guinea pigs resembles musculoskeletal aging in humans. We compared Dunkin Hartley guinea pigs to Strain 13 guinea pigs, which develop osteoarthritis much later in the lifespan. We measured myofiber type and size, muscle density, and long-term fractional protein synthesis rates of the gastrocnemius and soleus muscles in 5, 9, and 15-month-old guinea pigs. There was an age-related decline in skeletal muscle density, a greater proportion of smaller myofibers, and a decline in type II concomitant with a rise in type I myofibers in the gastrocnemius muscles from Dunkin Hartley guinea pigs only. These changes were accompanied by age-related declines in myofibrillar and mitochondrial protein synthesis in the gastrocnemius and soleus. Collectively, these findings suggest Dunkin Hartley guinea pigs experience myofiber remodeling alongside the progression of osteoarthritis, consistent with human musculoskeletal aging. Thus, Dunkin Hartley guinea pigs may be a model to advance discovery and therapeutic development for human musculoskeletal aging.
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Affiliation(s)
- Robert V Musci
- Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, United States
| | - Maureen A Walsh
- Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, United States
| | - Adam R Konopka
- Department of Medicine, University of Wisconsin-Madison, Madison, WI, United States.,GRECC, William S Middleton Memorial Veterans Hospital, Madison, WI, United States
| | - Christopher A Wolff
- Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, FL, United States
| | - Frederick F Peelor
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, United States
| | - Raoul F Reiser
- Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, United States
| | - Kelly S Santangelo
- Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, CO, United States
| | - Karyn L Hamilton
- Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, United States.,Columbine Health Systems Center for Healthy Aging, Colorado State University, Fort Collins, CO, United States
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Dietary protein, exercise, ageing and physical inactivity: interactive influences on skeletal muscle proteostasis. Proc Nutr Soc 2020; 80:106-117. [PMID: 33023679 DOI: 10.1017/s0029665120007879] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Dietary protein is a pre-requisite for the maintenance of skeletal muscle mass; stimulating increases in muscle protein synthesis (MPS), via essential amino acids (EAA), and attenuating muscle protein breakdown, via insulin. Muscles are receptive to the anabolic effects of dietary protein, and in particular the EAA leucine, for only a short period (i.e. about 2-3 h) in the rested state. Thereafter, MPS exhibits tachyphylaxis despite continued EAA availability and sustained mechanistic target of rapamycin complex 1 signalling. Other notable characteristics of this 'muscle full' phenomenon include: (i) it cannot be overcome by proximal intake of additional nutrient signals/substrates regulating MPS; meaning a refractory period exists before a next stimulation is possible, (ii) it is refractory to pharmacological/nutraceutical enhancement of muscle blood flow and thus is not induced by muscle hypo-perfusion, (iii) it manifests independently of whether protein intake occurs in a bolus or intermittent feeding pattern, and (iv) it does not appear to be dependent on protein dose per se. Instead, the main factor associated with altering muscle full is physical activity. For instance, when coupled to protein intake, resistance exercise delays the muscle full set-point to permit additional use of available EAA for MPS to promote muscle remodelling/growth. In contrast, ageing is associated with blunted MPS responses to protein/exercise (anabolic resistance), while physical inactivity (e.g. immobilisation) induces a premature muscle full, promoting muscle atrophy. It is crucial that in catabolic scenarios, anabolic strategies are sought to mitigate muscle decline. This review highlights regulatory protein turnover interactions by dietary protein, exercise, ageing and physical inactivity.
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76
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Sayda MH, Phillips BE, Williams JP, Greenhaff PL, Wilkinson DJ, Smith K, Atherton PJ. Associations between Plasma Branched Chain Amino Acids and Health Biomarkers in Response to Resistance Exercise Training Across Age. Nutrients 2020; 12:nu12103029. [PMID: 33023275 PMCID: PMC7601782 DOI: 10.3390/nu12103029] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/1970] [Revised: 09/24/2020] [Accepted: 09/30/2020] [Indexed: 01/10/2023] Open
Abstract
Leucine, isoleucine and valine (i.e., the branched chain amino acids, BCAA) play a key role in the support and regulation of tissue protein regulation and also as energy substrates. However, positive relationships exist between elevated levels of BCAA and insulin resistance (IR). Thus, we sought to investigate the links between fasting plasma BCAA following a progressive resistance exercise training (RET) programme, an intervention known to improve metabolic health. Fasting plasma BCAA were quantified in adults (young: 18-28 y, n = 8; middle-aged: 45-55 y, n = 9; older: 65-75 y, n = 15; BMI: 23-28 kg/m2, both males and females (~50:50), in a cross-sectional, intervention study. Participants underwent 20-weeks whole-body RET. Measurements of body composition, muscle strength (1-RM) and metabolic health biomarkers (e.g., HOMA-IR) were made pre- and post-RET. BCAA concentrations were determined by gas-chromatography mass spectrometry (GC-MS). No associations were observed across age with BCAA; however, RET elicited (p < 0.05) increases in plasma BCAA (all age-groups), while HOMA-IR scores reduced (p < 0.05) following RET. After RET, positive correlations in lean body mass (p = 0.007) and strength gains (p = 0.001) with fasting BCAA levels were observed. Elevated BCAA are not a robust marker of ageing nor IR in those with a healthy BMI; rather, despite decreasing IR, RET was associated with increased BCAA.
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Affiliation(s)
- Mariwan H. Sayda
- MRC-Versus Arthritis Centre for Musculoskeletal Ageing Research, University of Nottingham, Nottingham NG7 2RD, UK; (M.H.S.); (B.E.P.); (J.P.W.); (P.L.G.); (D.J.W.); (K.S.)
- The National Centre for Sport and Exercise Medicine—East Midlands, University of Nottingham, Nottingham NG7 2UH, UK
| | - Bethan E. Phillips
- MRC-Versus Arthritis Centre for Musculoskeletal Ageing Research, University of Nottingham, Nottingham NG7 2RD, UK; (M.H.S.); (B.E.P.); (J.P.W.); (P.L.G.); (D.J.W.); (K.S.)
- The National Centre for Sport and Exercise Medicine—East Midlands, University of Nottingham, Nottingham NG7 2UH, UK
- NIHR Biomedical Research Centre, University of Nottingham, Nottingham NG7 2UH, UK
| | - John P. Williams
- MRC-Versus Arthritis Centre for Musculoskeletal Ageing Research, University of Nottingham, Nottingham NG7 2RD, UK; (M.H.S.); (B.E.P.); (J.P.W.); (P.L.G.); (D.J.W.); (K.S.)
| | - Paul L. Greenhaff
- MRC-Versus Arthritis Centre for Musculoskeletal Ageing Research, University of Nottingham, Nottingham NG7 2RD, UK; (M.H.S.); (B.E.P.); (J.P.W.); (P.L.G.); (D.J.W.); (K.S.)
- The National Centre for Sport and Exercise Medicine—East Midlands, University of Nottingham, Nottingham NG7 2UH, UK
- NIHR Biomedical Research Centre, University of Nottingham, Nottingham NG7 2UH, UK
| | - Daniel J. Wilkinson
- MRC-Versus Arthritis Centre for Musculoskeletal Ageing Research, University of Nottingham, Nottingham NG7 2RD, UK; (M.H.S.); (B.E.P.); (J.P.W.); (P.L.G.); (D.J.W.); (K.S.)
- The National Centre for Sport and Exercise Medicine—East Midlands, University of Nottingham, Nottingham NG7 2UH, UK
- NIHR Biomedical Research Centre, University of Nottingham, Nottingham NG7 2UH, UK
| | - Ken Smith
- MRC-Versus Arthritis Centre for Musculoskeletal Ageing Research, University of Nottingham, Nottingham NG7 2RD, UK; (M.H.S.); (B.E.P.); (J.P.W.); (P.L.G.); (D.J.W.); (K.S.)
- The National Centre for Sport and Exercise Medicine—East Midlands, University of Nottingham, Nottingham NG7 2UH, UK
- NIHR Biomedical Research Centre, University of Nottingham, Nottingham NG7 2UH, UK
| | - Philip J. Atherton
- MRC-Versus Arthritis Centre for Musculoskeletal Ageing Research, University of Nottingham, Nottingham NG7 2RD, UK; (M.H.S.); (B.E.P.); (J.P.W.); (P.L.G.); (D.J.W.); (K.S.)
- The National Centre for Sport and Exercise Medicine—East Midlands, University of Nottingham, Nottingham NG7 2UH, UK
- NIHR Biomedical Research Centre, University of Nottingham, Nottingham NG7 2UH, UK
- Correspondence: ; Tel.: +01-332-724-725
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Angulo J, El Assar M, Álvarez-Bustos A, Rodríguez-Mañas L. Physical activity and exercise: Strategies to manage frailty. Redox Biol 2020; 35:101513. [PMID: 32234291 PMCID: PMC7284931 DOI: 10.1016/j.redox.2020.101513] [Citation(s) in RCA: 264] [Impact Index Per Article: 66.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Revised: 03/13/2020] [Accepted: 03/17/2020] [Indexed: 12/25/2022] Open
Abstract
Frailty, a consequence of the interaction of the aging process and certain chronic diseases, compromises functional outcomes in the elderly and substantially increases their risk for developing disabilities and other adverse outcomes. Frailty follows from the combination of several impaired physiological mechanisms affecting multiple organs and systems. And, though frailty and sarcopenia are related, they are two different conditions. Thus, strategies to preserve or improve functional status should consider systemic function in addition to muscle conditioning. Physical activity/exercise is considered one of the main strategies to counteract frailty-related physical impairment in the elderly. Exercise reduces age-related oxidative damage and chronic inflammation, increases autophagy, and improves mitochondrial function, myokine profile, insulin-like growth factor-1 (IGF-1) signaling pathway, and insulin sensitivity. Exercise interventions target resistance (strength and power), aerobic, balance, and flexibility work. Each type improves different aspects of physical functioning, though they could be combined according to need and prescribed as a multicomponent intervention. Therefore, exercise intervention programs should be prescribed based on an individual's physical functioning and adapted to the ensuing response.
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Affiliation(s)
- Javier Angulo
- Servicio de Histología-Investigación, Unidad de Investigación Traslacional en Cardiología (IRYCIS-UFV), Hospital Universitario Ramón y Cajal, Madrid, Spain; Centro de Investigación Biomédica en Red de Fragilidad y Envejecimiento Saludable (CIBERFES), Instituto de Salud Carlos III, Madrid, Spain
| | - Mariam El Assar
- Centro de Investigación Biomédica en Red de Fragilidad y Envejecimiento Saludable (CIBERFES), Instituto de Salud Carlos III, Madrid, Spain; Fundación para la Investigación Biomédica del Hospital Universitario de Getafe, Getafe, Spain
| | | | - Leocadio Rodríguez-Mañas
- Centro de Investigación Biomédica en Red de Fragilidad y Envejecimiento Saludable (CIBERFES), Instituto de Salud Carlos III, Madrid, Spain; Servicio de Geriatría, Hospital Universitario de Getafe, Getafe, Spain.
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78
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Marshall RN, Morgan PT, Martinez-Valdes E, Breen L. Quadriceps muscle electromyography activity during physical activities and resistance exercise modes in younger and older adults. Exp Gerontol 2020; 136:110965. [PMID: 32360986 PMCID: PMC7264709 DOI: 10.1016/j.exger.2020.110965] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 04/17/2020] [Accepted: 04/23/2020] [Indexed: 02/06/2023]
Abstract
BACKGROUND Understanding the root cause of the age-related impairment in muscle adaptive remodelling with resistance exercise training (RET) and developing pragmatic and accessible resistance exercise for older adults, are essential research directives. METHODS We sought to determine whether indices of quadriceps muscle EMG activity in response to different modes of RET and activities of daily living (ADL), differed between 15 healthy younger (25 ± 3 years) and 15 older (70 ± 5 years) adults. On four separate days, participants completed a maximal voluntary contraction (MVC) of the knee extensors, followed by a 15 m walking task, stair climbing task (i.e. ADL) and lower-limb RET through body-weight squats (BW-RET) and seated knee extensions on a machine (MN-RET) or via elastic bands (EB-RET). Surface quadriceps electromyography (EMG) was measured throughout all tasks to provide indirect estimates of changes in muscle activity. RESULTS MVC was significantly greater in young vs. older adults (Young: 256 ± 72 vs. Old: 137 ± 48 N·m, P < 0.001). EMG activity during all exercise tasks was significantly higher in older vs. younger adults when expressed relative to maximal EMG achieved during MVC (P < 0.01, for all). In addition, relative quadriceps muscle EMG activity was significantly greater in EB-RET (Young: 20.3 ± 8.7 vs. Old: 37.0 ± 10.7%) and MN-RET (Young: 22.9 ± 10.3, vs. Old: 37.8 ± 10.8%) compared with BW-RET (Young: 8.6 ± 2.9 vs. Old: 27.0 ± 9.3%), in young and older adults (P < 0.001). However, there was no significant difference in quadriceps EMG between EB-RET and MN-RET (P > 0.05). CONCLUSIONS In conclusion, relative quadriceps muscle EMG activity was higher across a range of activities/exercise modes in older vs. younger adults. The similar quadriceps muscle EMG activity between EB-RET and MN-RET provides a platform for detailed investigation of the neuromuscular and muscle metabolic responses to such pragmatic forms of RET to strengthen the evidence-base for this mode of RET as a potential countermeasure to sarcopenia.
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Affiliation(s)
- Ryan N Marshall
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, United Kingdom; MRC-Versus Arthritis Centre for Musculoskeletal Ageing Research, University of Birmingham, United Kingdom
| | - Paul T Morgan
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, United Kingdom; MRC-Versus Arthritis Centre for Musculoskeletal Ageing Research, University of Birmingham, United Kingdom
| | - Eduardo Martinez-Valdes
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, United Kingdom; Centre of Precision Rehabilitation for Spinal Pain (CPR Spine), School of Sport, Exercise and Rehabilitation Sciences, College of Life and Environmental Sciences, University of Birmingham, United Kingdom
| | - Leigh Breen
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, United Kingdom; MRC-Versus Arthritis Centre for Musculoskeletal Ageing Research, University of Birmingham, United Kingdom; NIHR, Birmingham Biomedical Research Centre, Birmingham, United Kingdom.
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79
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Novel Essential Amino Acid Supplements Following Resistance Exercise Induce Aminoacidemia and Enhance Anabolic Signaling Irrespective of Age: A Proof-of-Concept Trial. Nutrients 2020; 12:nu12072067. [PMID: 32664648 PMCID: PMC7400893 DOI: 10.3390/nu12072067] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Revised: 07/09/2020] [Accepted: 07/10/2020] [Indexed: 12/13/2022] Open
Abstract
We investigated the effects of ingesting a leucine-enriched essential amino acid (EAA) gel alone or combined with resistance exercise (RE) versus RE alone (control) on plasma aminoacidemia and intramyocellular anabolic signaling in healthy younger (28 ± 4 years) and older (71 ± 3 years) adults. Blood samples were obtained throughout the three trials, while muscle biopsies were collected in the postabsorptive state and 2 h following RE, following the consumption of two 50 mL EAA gels (40% leucine, 15 g total EAA), and following RE with EAA (combination (COM)). Protein content and the phosphorylation status of key anabolic signaling proteins were determined via immunoblotting. Irrespective of age, during EAA and COM peak leucinemia (younger: 454 ± 32 µM and 537 ± 111 µM; older: 417 ± 99 µM and 553 ± 136 µM) occurred ~60–120 min post-ingestion (younger: 66 ± 6 min and 120 ± 60 min; older: 90 ± 13 min and 78 ± 12 min). In the pooled sample, the area under the curve for plasma leucine and the sum of branched-chain amino acids was significantly greater in EAA and COM compared with RE. For intramyocellular signaling, significant main effects were found for condition (mTOR (Ser2481), rpS6 (Ser235/236)) and age (S6K1 (Thr421/Ser424), 4E-BP1 (Thr37/46)) in age group analyses. The phosphorylation of rpS6 was of similar magnitude (~8-fold) in pooled and age group data 2 h following COM. Our findings suggest that a gel-based, leucine-enriched EAA supplement is associated with aminoacidemia and a muscle anabolic signaling response, thus representing an effective means of stimulating muscle protein anabolism in younger and older adults following EAA and COM.
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80
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Fritzen AM, Thøgersen FD, Qadri KAN, Krag T, Sveen ML, Vissing J, Jeppesen TD. Preserved Capacity for Adaptations in Strength and Muscle Regulatory Factors in Elderly in Response to Resistance Exercise Training and Deconditioning. J Clin Med 2020; 9:jcm9072188. [PMID: 32664402 PMCID: PMC7408999 DOI: 10.3390/jcm9072188] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Revised: 07/07/2020] [Accepted: 07/09/2020] [Indexed: 12/12/2022] Open
Abstract
Aging is related to an inevitable loss of muscle mass and strength. The mechanisms behind age-related loss of muscle tissue are not fully understood but may, among other things, be induced by age-related differences in myogenic regulatory factors. Resistance exercise training and deconditioning offers a model to investigate differences in myogenic regulatory factors that may be important for age-related loss of muscle mass and strength. Nine elderly (82 ± 7 years old) and nine young, healthy persons (22 ± 2 years old) participated in the study. Exercise consisted of six weeks of resistance training of the quadriceps muscle followed by eight weeks of deconditioning. Muscle biopsy samples before and after training and during the deconditioning period were analyzed for MyoD, myogenin, insulin-like growth-factor I receptor, activin receptor IIB, smad2, porin, and citrate synthase. Muscle strength improved with resistance training by 78% (95.0 ± 22.0 kg) in the elderly to a similar extent as in the young participants (83.5%; 178.2 ± 44.2 kg) and returned to baseline in both groups after eight weeks of deconditioning. No difference was seen in expression of muscle regulatory factors between elderly and young in response to exercise training and deconditioning. In conclusion, the capacity to gain muscle strength with resistance exercise training in elderly was not impaired, highlighting this as a potent tool to combat age-related loss of muscle function, possibly due to preserved regulation of myogenic factors in elderly compared with young muscle.
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Affiliation(s)
- Andreas Mæchel Fritzen
- Department of Neurology, Copenhagen Neuromuscular Center, Rigshospitalet, DK-2100 Copenhagen, Denmark; (F.D.T.); (K.A.N.Q.); (T.K.); (M.-L.S.); (J.V.); (T.D.J.)
- Molecular Physiology Group, Department of Nutrition, Exercise, and Sports, Faculty of Science, University of Copenhagen, DK-2100 Copenhagen, Denmark
- Correspondence: ; Tel.: +45-42633359
| | - Frank D. Thøgersen
- Department of Neurology, Copenhagen Neuromuscular Center, Rigshospitalet, DK-2100 Copenhagen, Denmark; (F.D.T.); (K.A.N.Q.); (T.K.); (M.-L.S.); (J.V.); (T.D.J.)
| | - Khaled Abdul Nasser Qadri
- Department of Neurology, Copenhagen Neuromuscular Center, Rigshospitalet, DK-2100 Copenhagen, Denmark; (F.D.T.); (K.A.N.Q.); (T.K.); (M.-L.S.); (J.V.); (T.D.J.)
| | - Thomas Krag
- Department of Neurology, Copenhagen Neuromuscular Center, Rigshospitalet, DK-2100 Copenhagen, Denmark; (F.D.T.); (K.A.N.Q.); (T.K.); (M.-L.S.); (J.V.); (T.D.J.)
| | - Marie-Louise Sveen
- Department of Neurology, Copenhagen Neuromuscular Center, Rigshospitalet, DK-2100 Copenhagen, Denmark; (F.D.T.); (K.A.N.Q.); (T.K.); (M.-L.S.); (J.V.); (T.D.J.)
- Novo Nordisk A/S, DK-2860 Søborg, Denmark
| | - John Vissing
- Department of Neurology, Copenhagen Neuromuscular Center, Rigshospitalet, DK-2100 Copenhagen, Denmark; (F.D.T.); (K.A.N.Q.); (T.K.); (M.-L.S.); (J.V.); (T.D.J.)
| | - Tina D. Jeppesen
- Department of Neurology, Copenhagen Neuromuscular Center, Rigshospitalet, DK-2100 Copenhagen, Denmark; (F.D.T.); (K.A.N.Q.); (T.K.); (M.-L.S.); (J.V.); (T.D.J.)
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81
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McKendry J, Currier BS, Lim C, Mcleod JC, Thomas AC, Phillips SM. Nutritional Supplements to Support Resistance Exercise in Countering the Sarcopenia of Aging. Nutrients 2020; 12:E2057. [PMID: 32664408 PMCID: PMC7399875 DOI: 10.3390/nu12072057] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Revised: 07/07/2020] [Accepted: 07/08/2020] [Indexed: 12/17/2022] Open
Abstract
Skeletal muscle plays an indispensable role in metabolic health and physical function. A decrease in muscle mass and function with advancing age exacerbates the likelihood of mobility impairments, disease development, and early mortality. Therefore, the development of non-pharmacological interventions to counteract sarcopenia warrant significant attention. Currently, resistance training provides the most effective, low cost means by which to prevent sarcopenia progression and improve multiple aspects of overall health. Importantly, the impact of resistance training on skeletal muscle mass may be augmented by specific dietary components (i.e., protein), feeding strategies (i.e., timing, per-meal doses of specific macronutrients) and nutritional supplements (e.g., creatine, vitamin-D, omega-3 polyunsaturated fatty acids etc.). The purpose of this review is to provide an up-to-date, evidence-based account of nutritional strategies to enhance resistance training-induced adaptations in an attempt to combat age-related muscle mass loss. In addition, we provide insight on how to incorporate the aforementioned nutritional strategies that may support the growth or maintenance of skeletal muscle and subsequently extend the healthspan of older individuals.
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Affiliation(s)
| | | | | | | | | | - Stuart M. Phillips
- Exercise Metabolism Research Group, Department of Kinesiology, McMaster University, Hamilton, ON L8S 4L8, Canada; (J.M.); (B.S.C.); (C.L.); (J.C.M.); (A.C.Q.T.)
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82
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Lundberg TR, Martínez-Aranda LM, Sanz G, Hansson B, von Walden F, Tesch PA, Fernandez-Gonzalo R. Early accentuated muscle hypertrophy is strongly associated with myonuclear accretion. Am J Physiol Regul Integr Comp Physiol 2020; 319:R50-R58. [DOI: 10.1152/ajpregu.00061.2020] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The current study explored whether the marked hypertrophic response noted with a short-term unilateral concurrent exercise paradigm was associated with more prominent changes in myonuclei accretion, ribosome biogenesis, and capillarization compared with resistance exercise alone (RE). Ten men (age 25 ± 4 yr) performed aerobic and resistance exercise (AE + RE) for one leg while the other leg did RE. Muscle biopsies were obtained before and after 5 wk of training and subjected to fiber-type specific immunohistochemical analysis, and quantification of total RNA content and mRNA/rRNA transcript abundance. Type II fiber cross-sectional area (CSA) increased with both AE + RE (22%) and RE (16%), while type I fiber CSA increased mainly with AE + RE (16%). The change score tended to differ between legs for type I CSA ( P = 0.099), and the increase in smallest fiber diameter was greater in AE + RE than RE ( P = 0.029). The number of nuclei per fiber increased after AE + RE in both fiber types, and this increase was greater ( P = 0.027) than after RE. A strong correlation was observed between changes in number of nuclei per fiber and fiber CSA in both fiber types, for both AE + RE and RE ( r > 0.8, P < 0.004). RNA content increased after AE + RE (24%, P = 0.019), but the change-scores did not differ across legs. The capillary variables generally increased in both fiber types, with no difference across legs. In conclusion, the accentuated hypertrophic response to AE + RE was associated with more pronounced myonuclear accretion, which was strongly correlated with the degree of fiber hypertrophy. This suggests that myonuclear accretion could play a role in facilitating muscle hypertrophy also during very short training periods.
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Affiliation(s)
- Tommy R. Lundberg
- Division of Clinical Physiology, Department of Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden
- Unit of Clinical Physiology, Karolinska University Hospital, Stockholm, Sweden
| | - Luis Manuel Martínez-Aranda
- Division of Clinical Physiology, Department of Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden
- Unit of Clinical Physiology, Karolinska University Hospital, Stockholm, Sweden
- Faculty of Sport, Neuroscience of Human Movement Research Group (Neuromove), Catholic University of San Antonio, Murcia, Spain
| | - Gema Sanz
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
- Gnomics, Murcia, Spain
| | - Björn Hansson
- Division of Clinical Physiology, Department of Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden
- Unit of Clinical Physiology, Karolinska University Hospital, Stockholm, Sweden
| | - Ferdinand von Walden
- Neuropediatrics Unit, Department of Women’s and Children’s Health, Karolinska Institutet, Stockholm, Sweden
| | - Per A. Tesch
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Rodrigo Fernandez-Gonzalo
- Division of Clinical Physiology, Department of Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden
- Unit of Clinical Physiology, Karolinska University Hospital, Stockholm, Sweden
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83
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Farrash W, Brook M, Crossland H, Phillips BE, Cegielski J, Wilkinson DJ, Constantin-Teodosiu D, Greenhaff PL, Smith K, Cleasby M, Atherton PJ. Impacts of rat hindlimb Fndc5/irisin overexpression on muscle and adipose tissue metabolism. Am J Physiol Endocrinol Metab 2020; 318:E943-E955. [PMID: 32369414 PMCID: PMC7311674 DOI: 10.1152/ajpendo.00034.2020] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Myokines, such as irisin, have been purported to exert physiological effects on skeletal muscle in an autocrine/paracrine fashion. In this study, we aimed to investigate the mechanistic role of in vivo fibronectin type III domain-containing 5 (Fndc5)/irisin upregulation in muscle. Overexpression (OE) of Fndc5 in rat hindlimb muscle was achieved by in vivo electrotransfer, i.e., bilateral injections of Fndc5 harboring vectors for OE rats (n = 8) and empty vector for control rats (n = 8). Seven days later, a bolus of D2O (7.2 mL/kg) was administered via oral gavage to quantify muscle protein synthesis. After an overnight fast, on day 9, 2-deoxy-d-glucose-6-phosphate (2-DG6P; 6 mg/kg) was provided during an intraperitoneal glucose tolerance test (2 g/kg) to assess glucose handling. Animals were euthanized, musculus tibialis cranialis muscles and subcutaneous fat (inguinal) were harvested, and metabolic and molecular effects were evaluated. Muscle Fndc5 mRNA increased with OE (~2-fold; P = 0.014), leading to increased circulating irisin (1.5 ± 0.9 to 3.5 ± 1.2 ng/mL; P = 0.049). OE had no effect on protein anabolism or mitochondrial biogenesis; however, muscle glycogen was increased, along with glycogen synthase 1 gene expression (P = 0.04 and 0.02, respectively). In addition to an increase in glycogen synthase activation in OE (P = 0.03), there was a tendency toward increased glucose transporter 4 protein (P = 0.09). However, glucose uptake (accumulation of 2-DG6P) was identical. Irisin elicited no endocrine effect on mitochondrial biogenesis or uncoupling proteins in white adipose tissue. Hindlimb overexpression led to physiological increases in Fndc5/irisin. However, our data indicate limited short-term impacts of irisin in relation to muscle anabolism, mitochondrial biogenesis, glucose uptake, or adipose remodeling.
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Affiliation(s)
- W Farrash
- Medical Research Council Versus Arthritis Centre for Musculoskeletal Ageing Research and Nottingham National Institute for Health Research Biomedical Research Centre, School of Medicine, University of Nottingham, Derby, United Kingdom
- College of Applied Medical Sciences, Umm Al-Qura University, Makkah, Saudi Arabia
| | - M Brook
- Medical Research Council Versus Arthritis Centre for Musculoskeletal Ageing Research and Nottingham National Institute for Health Research Biomedical Research Centre, School of Medicine, University of Nottingham, Derby, United Kingdom
| | - H Crossland
- Medical Research Council Versus Arthritis Centre for Musculoskeletal Ageing Research and Nottingham National Institute for Health Research Biomedical Research Centre, School of Medicine, University of Nottingham, Derby, United Kingdom
| | - B E Phillips
- Medical Research Council Versus Arthritis Centre for Musculoskeletal Ageing Research and Nottingham National Institute for Health Research Biomedical Research Centre, School of Medicine, University of Nottingham, Derby, United Kingdom
| | - J Cegielski
- Medical Research Council Versus Arthritis Centre for Musculoskeletal Ageing Research and Nottingham National Institute for Health Research Biomedical Research Centre, School of Medicine, University of Nottingham, Derby, United Kingdom
| | - D J Wilkinson
- Medical Research Council Versus Arthritis Centre for Musculoskeletal Ageing Research and Nottingham National Institute for Health Research Biomedical Research Centre, School of Medicine, University of Nottingham, Derby, United Kingdom
| | - D Constantin-Teodosiu
- Medical Research Council Versus Arthritis Centre for Musculoskeletal Ageing Research, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - P L Greenhaff
- Medical Research Council Versus Arthritis Centre for Musculoskeletal Ageing Research, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - K Smith
- Medical Research Council Versus Arthritis Centre for Musculoskeletal Ageing Research and Nottingham National Institute for Health Research Biomedical Research Centre, School of Medicine, University of Nottingham, Derby, United Kingdom
| | - M Cleasby
- Molecular Physiology of Diabetes Laboratory, Department of Comparative Biomedical Sciences, Royal Veterinary College, University of London, London, United Kingdom
| | - P J Atherton
- Medical Research Council Versus Arthritis Centre for Musculoskeletal Ageing Research and Nottingham National Institute for Health Research Biomedical Research Centre, School of Medicine, University of Nottingham, Derby, United Kingdom
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84
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Brook MS, Wilkinson DJ. Contemporary stable isotope tracer approaches: Insights into skeletal muscle metabolism in health and disease. Exp Physiol 2020; 105:1081-1089. [PMID: 32362047 DOI: 10.1113/ep087492] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Accepted: 04/27/2020] [Indexed: 12/18/2022]
Abstract
NEW FINDINGS What is the topic of this review? This review discusses the application of new stable isotope tracer techniques in understanding the control of skeletal muscle mass. What advances does it highlight? This review highlights current advances in stable isotope tracer techniques through their combination with high-throughput proteomics technologies. ABSTRACT Beyond its primary locomotory and key structural functions, skeletal muscle provides additional vital roles for maintenance of metabolic health, acting as a storage point for glucose and intramuscular lipids for energy production, alongside being the largest reservoir for amino acids in the body. Therefore, maintenance of muscle mass is key to the promotion of health and well-being across the lifespan and in several disease states. As such, when skeletal muscle is lost, in either clinical (cancer, organ failure etc.) or non-clinical (ageing, inactivity) situations, there are potentially devastating consequences attached, with robust links existing between muscle mass loss and mortality. Great efforts are being made to reverse or slow muscle mass declines in health and disease, through combinations of lifestyle changes and nutritional and/or pharmaceutical intervention. However, despite this comprehensive research effort, the underlying metabolic and molecular mechanisms have yet to be defined properly. However, with the rapid acceleration of analytical developments over recent years, the application of stable isotope tracers to the study of human muscle metabolism is providing unique insights into the mechanisms controlling skeletal muscle loss and allowing more targeted therapeutic strategies to be developed. The aim of this review is to highlight the technical breakthroughs in our understanding of muscle wasting in health and disease and how future directions and developments incorporating 'omics' with stable isotope tracers will allow for a more personalized and stratified therapeutic approach.
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Affiliation(s)
- Matthew S Brook
- MRC-Versus Arthritis Centre for Musculoskeletal Ageing Research, National Institute for Health Research Nottingham Biomedical Research Centre, University of Nottingham, Nottingham, UK.,School of Life Science, Queen's Medical Centre, Nottingham, UK
| | - Daniel J Wilkinson
- MRC-Versus Arthritis Centre for Musculoskeletal Ageing Research, National Institute for Health Research Nottingham Biomedical Research Centre, University of Nottingham, Nottingham, UK.,Division of Health Sciences and Graduate Entry Medicine, School of Medicine, Royal Derby Hospital Centre, Derby, UK
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85
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Davies RW, Bass JJ, Carson BP, Norton C, Kozior M, Wilkinson DJ, Brook MS, Atherton PJ, Smith K, Jakeman PM. The Effect of Whey Protein Supplementation on Myofibrillar Protein Synthesis and Performance Recovery in Resistance-Trained Men. Nutrients 2020; 12:nu12030845. [PMID: 32245197 PMCID: PMC7146144 DOI: 10.3390/nu12030845] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 03/18/2020] [Accepted: 03/20/2020] [Indexed: 01/25/2023] Open
Abstract
BACKGROUND The aim of this study was to investigate the effect of whey protein supplementation on myofibrillar protein synthesis (myoPS) and muscle recovery over a 7-d period of intensified resistance training (RT). METHODS In a double-blind randomised parallel group design, 16 resistance-trained men aged 18 to 35 years completed a 7-d RT protocol, consisting of three lower-body RT sessions on non-consecutive days. Participants consumed a controlled diet (146 kJ·kg-1·d-1, 1.7 g·kg-1·d-1 protein) with either a whey protein supplement or an isonitrogenous control (0.33 g·kg-1·d-1 protein). To measure myoPS, 400 ml of deuterium oxide (D2O) (70 atom %) was ingested the day prior to starting the study and m. vastus lateralis biopsies were taken before and after RT-intervention. Myofibrillar fractional synthetic rate (myoFSR) was calculated via deuterium labelling of myofibrillar-bound alanine, measured by gas chromatography-pyrolysis-isotope ratio mass spectrometry (GC-Pyr-IRMS). Muscle recovery parameters (i.e., countermovement jump height, isometric-squat force, muscle soreness and serum creatine kinase) were assessed daily. RESULTS MyoFSR PRE was 1.6 (0.2) %∙d-1 (mean (SD)). Whey protein supplementation had no effect on myoFSR (p = 0.771) or any recovery parameter (p = 0.390-0.989). CONCLUSIONS Over an intense 7-d RT protocol, 0.33 g·kg-1·d-1 of supplemental whey protein does not enhance day-to-day measures of myoPS or postexercise recovery in resistance-trained men.
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Affiliation(s)
- Robert W. Davies
- Department of Physical Education & Sport Sciences, University of Limerick, V94 T9PX Limerick, Ireland; (J.J.B.); (B.P.C.); (C.N.); (M.K.); (P.M.J.)
- Food for Health Ireland (FHI), Centre for Interventions in Infection, Inflammation & Immunity, University of Limerick, V94 T9PX Limerick, Ireland
- Correspondence: ; Tel.: +353-6123-3203
| | - Joseph J. Bass
- Department of Physical Education & Sport Sciences, University of Limerick, V94 T9PX Limerick, Ireland; (J.J.B.); (B.P.C.); (C.N.); (M.K.); (P.M.J.)
- Food for Health Ireland (FHI), Centre for Interventions in Infection, Inflammation & Immunity, University of Limerick, V94 T9PX Limerick, Ireland
- Medical Research Council (MRC) and Arthritis Research United Kingdom (ARUK) Centre for Musculoskeletal Aging Research and National Institute for Health Research, Nottingham Biomedical Research Centre, University of Nottingham, Nottingham NG7 2UH, UK; (D.J.W.); (M.S.B.); (P.J.A.); (K.S.)
| | - Brian P. Carson
- Department of Physical Education & Sport Sciences, University of Limerick, V94 T9PX Limerick, Ireland; (J.J.B.); (B.P.C.); (C.N.); (M.K.); (P.M.J.)
- Food for Health Ireland (FHI), Centre for Interventions in Infection, Inflammation & Immunity, University of Limerick, V94 T9PX Limerick, Ireland
- Health Research Institute (HRI), University of Limerick, V94 T9PX Ireland, Ireland
| | - Catherine Norton
- Department of Physical Education & Sport Sciences, University of Limerick, V94 T9PX Limerick, Ireland; (J.J.B.); (B.P.C.); (C.N.); (M.K.); (P.M.J.)
- Food for Health Ireland (FHI), Centre for Interventions in Infection, Inflammation & Immunity, University of Limerick, V94 T9PX Limerick, Ireland
- Health Research Institute (HRI), University of Limerick, V94 T9PX Ireland, Ireland
| | - Marta Kozior
- Department of Physical Education & Sport Sciences, University of Limerick, V94 T9PX Limerick, Ireland; (J.J.B.); (B.P.C.); (C.N.); (M.K.); (P.M.J.)
- Food for Health Ireland (FHI), Centre for Interventions in Infection, Inflammation & Immunity, University of Limerick, V94 T9PX Limerick, Ireland
| | - Daniel J. Wilkinson
- Medical Research Council (MRC) and Arthritis Research United Kingdom (ARUK) Centre for Musculoskeletal Aging Research and National Institute for Health Research, Nottingham Biomedical Research Centre, University of Nottingham, Nottingham NG7 2UH, UK; (D.J.W.); (M.S.B.); (P.J.A.); (K.S.)
| | - Matthew S. Brook
- Medical Research Council (MRC) and Arthritis Research United Kingdom (ARUK) Centre for Musculoskeletal Aging Research and National Institute for Health Research, Nottingham Biomedical Research Centre, University of Nottingham, Nottingham NG7 2UH, UK; (D.J.W.); (M.S.B.); (P.J.A.); (K.S.)
| | - Philip J. Atherton
- Medical Research Council (MRC) and Arthritis Research United Kingdom (ARUK) Centre for Musculoskeletal Aging Research and National Institute for Health Research, Nottingham Biomedical Research Centre, University of Nottingham, Nottingham NG7 2UH, UK; (D.J.W.); (M.S.B.); (P.J.A.); (K.S.)
| | - Ken Smith
- Medical Research Council (MRC) and Arthritis Research United Kingdom (ARUK) Centre for Musculoskeletal Aging Research and National Institute for Health Research, Nottingham Biomedical Research Centre, University of Nottingham, Nottingham NG7 2UH, UK; (D.J.W.); (M.S.B.); (P.J.A.); (K.S.)
| | - Philip M. Jakeman
- Department of Physical Education & Sport Sciences, University of Limerick, V94 T9PX Limerick, Ireland; (J.J.B.); (B.P.C.); (C.N.); (M.K.); (P.M.J.)
- Food for Health Ireland (FHI), Centre for Interventions in Infection, Inflammation & Immunity, University of Limerick, V94 T9PX Limerick, Ireland
- Health Research Institute (HRI), University of Limerick, V94 T9PX Ireland, Ireland
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86
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Karlsen A, Soendenbroe C, Malmgaard-Clausen NM, Wagener F, Moeller CE, Senhaji Z, Damberg K, Andersen JL, Schjerling P, Kjaer M, Mackey AL. Preserved capacity for satellite cell proliferation, regeneration, and hypertrophy in the skeletal muscle of healthy elderly men. FASEB J 2020; 34:6418-6436. [PMID: 32167202 DOI: 10.1096/fj.202000196r] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Revised: 03/02/2020] [Accepted: 03/03/2020] [Indexed: 01/30/2023]
Abstract
Blunted muscle hypertrophy and impaired regeneration with aging have been partly attributed to satellite cell (SC) dysfunction. However, true muscle regeneration has not yet been studied in elderly individuals. To investigate this, muscle injury was induced by 200 electrically stimulated (ES) eccentric contractions of the vastus lateralis (VL) of one leg in seven young (20-31 years) and 19 elderly men (60-73 years). This was followed by 13 weeks of resistance training (RT) for both legs to investigate the capacity for hypertrophy. Muscle biopsies were collected Pre- and Post-RT, and 9 days after ES, for immunohistochemistry and RT-PCR. Hypertrophy was assessed by MRI, DEXA, and immunohistochemistry. Overall, surprisingly comparable responses were observed between the young and elderly. Nine days after ES, Pax7+ SC number had doubled (P < .05), alongside necrosis and substantial changes in expression of genes related to matrix, myogenesis, and innervation (P < .05). Post-RT, VL cross-sectional area had increased in both legs (~15%, P < .05) and SCs/type II fiber had increased ~2-4 times more with ES+RT vs RT alone (P < .001). Together these novel findings demonstrate "youthful" regeneration and hypertrophy responses in human elderly muscle. Furthermore, boosting SC availability in healthy elderly men does not enhance the subsequent muscle hypertrophy response to RT.
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Affiliation(s)
- Anders Karlsen
- Department of Orthopaedic Surgery M, Institute of Sports Medicine Copenhagen, Bispebjerg Hospital, Copenhagen, Denmark.,Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Faculty of Health and Medical Sciences, Center for Healthy Aging, University of Copenhagen, Copenhagen, Denmark
| | - Casper Soendenbroe
- Department of Orthopaedic Surgery M, Institute of Sports Medicine Copenhagen, Bispebjerg Hospital, Copenhagen, Denmark.,Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Faculty of Health and Medical Sciences, Center for Healthy Aging, University of Copenhagen, Copenhagen, Denmark
| | - Nikolaj M Malmgaard-Clausen
- Department of Orthopaedic Surgery M, Institute of Sports Medicine Copenhagen, Bispebjerg Hospital, Copenhagen, Denmark.,Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Faculty of Health and Medical Sciences, Center for Healthy Aging, University of Copenhagen, Copenhagen, Denmark
| | - Frederik Wagener
- Department of Orthopaedic Surgery M, Institute of Sports Medicine Copenhagen, Bispebjerg Hospital, Copenhagen, Denmark
| | - Casper Emil Moeller
- Department of Orthopaedic Surgery M, Institute of Sports Medicine Copenhagen, Bispebjerg Hospital, Copenhagen, Denmark
| | - Zouhir Senhaji
- Department of Orthopaedic Surgery M, Institute of Sports Medicine Copenhagen, Bispebjerg Hospital, Copenhagen, Denmark
| | - Kristine Damberg
- Department of Orthopaedic Surgery M, Institute of Sports Medicine Copenhagen, Bispebjerg Hospital, Copenhagen, Denmark
| | - Jesper Løvind Andersen
- Department of Orthopaedic Surgery M, Institute of Sports Medicine Copenhagen, Bispebjerg Hospital, Copenhagen, Denmark.,Faculty of Health and Medical Sciences, Center for Healthy Aging, University of Copenhagen, Copenhagen, Denmark
| | - Peter Schjerling
- Department of Orthopaedic Surgery M, Institute of Sports Medicine Copenhagen, Bispebjerg Hospital, Copenhagen, Denmark.,Faculty of Health and Medical Sciences, Center for Healthy Aging, University of Copenhagen, Copenhagen, Denmark
| | - Michael Kjaer
- Department of Orthopaedic Surgery M, Institute of Sports Medicine Copenhagen, Bispebjerg Hospital, Copenhagen, Denmark.,Faculty of Health and Medical Sciences, Center for Healthy Aging, University of Copenhagen, Copenhagen, Denmark
| | - Abigail L Mackey
- Department of Orthopaedic Surgery M, Institute of Sports Medicine Copenhagen, Bispebjerg Hospital, Copenhagen, Denmark.,Xlab, Department of Biomedical Sciences, Faculty of Health and Medical Sciences, Center for Healthy Aging, University of Copenhagen, Copenhagen, Denmark
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87
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Joanisse S, Lim C, McKendry J, Mcleod JC, Stokes T, Phillips SM. Recent advances in understanding resistance exercise training-induced skeletal muscle hypertrophy in humans. F1000Res 2020; 9. [PMID: 32148775 PMCID: PMC7043134 DOI: 10.12688/f1000research.21588.1] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 02/18/2020] [Indexed: 12/22/2022] Open
Abstract
Skeletal muscle plays a pivotal role in the maintenance of physical and metabolic health and, critically, mobility. Accordingly, strategies focused on increasing the quality and quantity of skeletal muscle are relevant, and resistance exercise is foundational to the process of functional hypertrophy. Much of our current understanding of skeletal muscle hypertrophy can be attributed to the development and utilization of stable isotopically labeled tracers. We know that resistance exercise and sufficient protein intake act synergistically and provide the most effective stimuli to enhance skeletal muscle mass; however, the molecular intricacies that underpin the tremendous response variability to resistance exercise-induced hypertrophy are complex. The purpose of this review is to discuss recent studies with the aim of shedding light on key regulatory mechanisms that dictate hypertrophic gains in skeletal muscle mass. We also aim to provide a brief up-to-date summary of the recent advances in our understanding of skeletal muscle hypertrophy in response to resistance training in humans.
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Affiliation(s)
- Sophie Joanisse
- Exercise Metabolism Research Group, Department of Kinesiology, McMaster University, Hamilton, ON, Canada
| | - Changhyun Lim
- Exercise Metabolism Research Group, Department of Kinesiology, McMaster University, Hamilton, ON, Canada
| | - James McKendry
- Exercise Metabolism Research Group, Department of Kinesiology, McMaster University, Hamilton, ON, Canada
| | - Jonathan C Mcleod
- Exercise Metabolism Research Group, Department of Kinesiology, McMaster University, Hamilton, ON, Canada
| | - Tanner Stokes
- Exercise Metabolism Research Group, Department of Kinesiology, McMaster University, Hamilton, ON, Canada
| | - Stuart M Phillips
- Exercise Metabolism Research Group, Department of Kinesiology, McMaster University, Hamilton, ON, Canada
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88
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Hammarström D, Øfsteng S, Koll L, Hanestadhaugen M, Hollan I, Apró W, Whist JE, Blomstrand E, Rønnestad BR, Ellefsen S. Benefits of higher resistance-training volume are related to ribosome biogenesis. J Physiol 2020; 598:543-565. [PMID: 31813190 DOI: 10.1113/jp278455] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Accepted: 12/03/2019] [Indexed: 12/25/2022] Open
Abstract
KEY POINTS For individuals showing suboptimal adaptations to resistance training, manipulation of training volume is a potential measure to facilitate responses. This remains unexplored. Here, 34 untrained individuals performed contralateral resistance training with moderate and low volume for 12 weeks. Moderate volume led to larger increases in muscle cross-sectional area, strength and type II fibre-type transitions. These changes coincided with greater activation of signalling pathways controlling muscle growth and greater induction of ribosome synthesis. Out of 34 participants, thirteen displayed clear benefit of MOD on muscle hypertrophy and sixteen showed clear benefit of MOD on muscle strength gains. This coincided with greater total RNA accumulation in the early phase of the training period, suggesting that ribosomal biogenesis regulates the dose-response relationship between training volume and muscle hypertrophy. These results demonstrate that there is a dose-dependent relationship between training volume and outcomes. On the individual level, benefits of higher training volume were associated with increased ribosomal biogenesis. ABSTRACT Resistance-exercise volume is a determinant of training outcomes. However not all individuals respond in a dose-dependent fashion. In this study, 34 healthy individuals (males n = 16, 23.6 (4.1) years; females n = 18, 22.0 (1.3) years) performed moderate- (3 sets per exercise, MOD) and low-volume (1 set, LOW) resistance training in a contralateral fashion for 12 weeks (2-3 sessions per week). Muscle cross-sectional area (CSA) and strength were assessed at Weeks 0 and 12, along with biopsy sampling (m. vastus lateralis). Muscle biopsies were also sampled before and 1 h after the fifth session (Week 2). MOD resulted in larger increases in muscle CSA (5.2 (3.8)% versus 3.7 (3.7)%, P < 0.001) and strength (3.4-7.7% difference, all P < 0.05. This coincided with greater reductions in type IIX fibres from Week 0 to Week 12 (MOD, -4.6 percentage points; LOW -3.2 percentage points), greater phosphorylation of S6-kinase 1 (p85 S6K1Thr412 , 19%; p70 S6K1Thr389 , 58%) and ribosomal protein S6Ser235/236 (37%), greater rested-state total RNA (8.8%) and greater exercise-induced c-Myc mRNA expression (25%; Week 2, all P < 0.05). Thirteen and sixteen participants, respectively, displayed clear benefits in response to MOD on muscle hypertrophy and strength. Benefits were associated with greater accumulation of total RNA at Week 2 in the MOD leg, with every 1% difference increasing the odds of MOD benefit by 7.0% (P = 0.005) and 9.8% (P = 0.002). In conclusion, MOD led to greater functional and biological adaptations than LOW. Associations between dose-dependent total RNA accumulation and increases in muscle mass and strength point to ribosome biogenesis as a determinant of dose-dependent training responses.
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Affiliation(s)
- Daniel Hammarström
- Section for Health and Exercise Physiology, Department of Public Health and Sport Sciences, Inland Norway University of Applied Sciences, Elverum, Norway.,Swedish School of Sport and Health Sciences, Box 5626, SE-114 86, Stockholm, Sweden
| | - Sjur Øfsteng
- Section for Health and Exercise Physiology, Department of Public Health and Sport Sciences, Inland Norway University of Applied Sciences, Elverum, Norway
| | - Lise Koll
- Innlandet Hospital Trust, Postboks 990, 2629, Lillehammer, Norway
| | | | - Ivana Hollan
- Hospital for Rheumatic Diseases, Magrethe Grundtvigsvei 6, 2609, Lillehammer, Norway.,Brigham and Women's Hospital, 75 Francis Street, Boston, MA, 02115, USA
| | - William Apró
- Swedish School of Sport and Health Sciences, Box 5626, SE-114 86, Stockholm, Sweden
| | - Jon Elling Whist
- Innlandet Hospital Trust, Postboks 990, 2629, Lillehammer, Norway
| | - Eva Blomstrand
- Swedish School of Sport and Health Sciences, Box 5626, SE-114 86, Stockholm, Sweden
| | - Bent R Rønnestad
- Section for Health and Exercise Physiology, Department of Public Health and Sport Sciences, Inland Norway University of Applied Sciences, Elverum, Norway
| | - Stian Ellefsen
- Section for Health and Exercise Physiology, Department of Public Health and Sport Sciences, Inland Norway University of Applied Sciences, Elverum, Norway.,Innlandet Hospital Trust, Postboks 990, 2629, Lillehammer, Norway
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89
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Willis CR, Ames RM, Deane CS, Phillips BE, Boereboom CL, Abdulla H, Bukhari SS, Lund JN, Williams JP, Wilkinson DJ, Smith K, Kadi F, Szewczyk NJ, Atherton PJ, Etheridge T. Network analysis of human muscle adaptation to aging and contraction. Aging (Albany NY) 2020; 12:740-755. [PMID: 31910159 PMCID: PMC6977671 DOI: 10.18632/aging.102653] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Accepted: 12/24/2019] [Indexed: 12/21/2022]
Abstract
Resistance exercise (RE) remains a primary approach for minimising aging muscle decline. Understanding muscle adaptation to individual contractile components of RE (eccentric, concentric) might optimise RE-based intervention strategies. Herein, we employed a network-driven pipeline to identify putative molecular drivers of muscle aging and contraction mode responses. RNA-sequencing data was generated from young (21±1 y) and older (70±1 y) human skeletal muscle before and following acute unilateral concentric and contralateral eccentric contractions. Application of weighted gene co-expression network analysis identified 33 distinct gene clusters ('modules') with an expression profile regulated by aging, contraction and/or linked to muscle strength. These included two contraction 'responsive' modules (related to 'cell adhesion' and 'transcription factor' processes) that also correlated with the magnitude of post-exercise muscle strength decline. Module searches for 'hub' genes and enriched transcription factor binding sites established a refined set of candidate module-regulatory molecules (536 hub genes and 60 transcription factors) as possible contributors to muscle aging and/or contraction responses. Thus, network-driven analysis can identify new molecular candidates of functional relevance to muscle aging and contraction mode adaptations.
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Affiliation(s)
- Craig R.G. Willis
- Department of Sport and Health Sciences, College of Life and Environmental Sciences, University of Exeter, Exeter EX1 2LU, UK
| | - Ryan M. Ames
- Biosciences, University of Exeter, Exeter EX4 4QD, UK
| | - Colleen S. Deane
- Department of Sport and Health Sciences, College of Life and Environmental Sciences, University of Exeter, Exeter EX1 2LU, UK
| | - Bethan E. Phillips
- MRC-ARUK Centre for Musculoskeletal aging Research and National Institute of Health Research, Biomedical Research Centre, Royal Derby Hospital Centre, School of Medicine, University of Nottingham, Derby DE22 3DT, UK
| | - Catherine L. Boereboom
- MRC-ARUK Centre for Musculoskeletal aging Research and National Institute of Health Research, Biomedical Research Centre, Royal Derby Hospital Centre, School of Medicine, University of Nottingham, Derby DE22 3DT, UK
| | - Haitham Abdulla
- MRC-ARUK Centre for Musculoskeletal aging Research and National Institute of Health Research, Biomedical Research Centre, Royal Derby Hospital Centre, School of Medicine, University of Nottingham, Derby DE22 3DT, UK
| | - Syed S.I. Bukhari
- MRC-ARUK Centre for Musculoskeletal aging Research and National Institute of Health Research, Biomedical Research Centre, Royal Derby Hospital Centre, School of Medicine, University of Nottingham, Derby DE22 3DT, UK
| | - Jonathan N. Lund
- Department of Surgery, Postgraduate Entry Medical School, Royal Derby Hospital Centre, School of Medicine, University of Nottingham, Derby DE22 3DT, UK
| | - John P. Williams
- MRC-ARUK Centre for Musculoskeletal aging Research and National Institute of Health Research, Biomedical Research Centre, Royal Derby Hospital Centre, School of Medicine, University of Nottingham, Derby DE22 3DT, UK
- Department of Surgery, Postgraduate Entry Medical School, Royal Derby Hospital Centre, School of Medicine, University of Nottingham, Derby DE22 3DT, UK
| | - Daniel J. Wilkinson
- MRC-ARUK Centre for Musculoskeletal aging Research and National Institute of Health Research, Biomedical Research Centre, Royal Derby Hospital Centre, School of Medicine, University of Nottingham, Derby DE22 3DT, UK
| | - Kenneth Smith
- MRC-ARUK Centre for Musculoskeletal aging Research and National Institute of Health Research, Biomedical Research Centre, Royal Derby Hospital Centre, School of Medicine, University of Nottingham, Derby DE22 3DT, UK
| | - Fawzi Kadi
- School of Health Sciences, Örebro University, Örebro 70182, Sweden
| | - Nathaniel J. Szewczyk
- MRC-ARUK Centre for Musculoskeletal aging Research and National Institute of Health Research, Biomedical Research Centre, Royal Derby Hospital Centre, School of Medicine, University of Nottingham, Derby DE22 3DT, UK
| | - Philip J. Atherton
- MRC-ARUK Centre for Musculoskeletal aging Research and National Institute of Health Research, Biomedical Research Centre, Royal Derby Hospital Centre, School of Medicine, University of Nottingham, Derby DE22 3DT, UK
| | - Timothy Etheridge
- Department of Sport and Health Sciences, College of Life and Environmental Sciences, University of Exeter, Exeter EX1 2LU, UK
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90
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Hackney AC, Smith-Ryan AE, Fink JE. Methodological Considerations in Exercise Endocrinology. ENDOCRINOLOGY OF PHYSICAL ACTIVITY AND SPORT 2020. [DOI: 10.1007/978-3-030-33376-8_1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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91
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Kraemer WJ, Ratamess NA, Hymer WC, Nindl BC, Fragala MS. Growth Hormone(s), Testosterone, Insulin-Like Growth Factors, and Cortisol: Roles and Integration for Cellular Development and Growth With Exercise. Front Endocrinol (Lausanne) 2020; 11:33. [PMID: 32158429 PMCID: PMC7052063 DOI: 10.3389/fendo.2020.00033] [Citation(s) in RCA: 121] [Impact Index Per Article: 30.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Accepted: 01/16/2020] [Indexed: 12/16/2022] Open
Abstract
Hormones are largely responsible for the integrated communication of several physiological systems responsible for modulating cellular growth and development. Although the specific hormonal influence must be considered within the context of the entire endocrine system and its relationship with other physiological systems, three key hormones are considered the "anabolic giants" in cellular growth and repair: testosterone, the growth hormone superfamily, and the insulin-like growth factor (IGF) superfamily. In addition to these anabolic hormones, glucocorticoids, mainly cortisol must also be considered because of their profound opposing influence on human skeletal muscle anabolism in many instances. This review presents emerging research on: (1) Testosterone signaling pathways, responses, and adaptations to resistance training; (2) Growth hormone: presents new complexity with exercise stress; (3) Current perspectives on IGF-I and physiological adaptations and complexity these hormones as related to training; and (4) Glucocorticoid roles in integrated communication for anabolic/catabolic signaling. Specifically, the review describes (1) Testosterone as the primary anabolic hormone, with an anabolic influence largely dictated primarily by genomic and possible non-genomic signaling, satellite cell activation, interaction with other anabolic signaling pathways, upregulation or downregulation of the androgen receptor, and potential roles in co-activators and transcriptional activity; (2) Differential influences of growth hormones depending on the "type" of the hormone being assayed and the magnitude of the physiological stress; (3) The exquisite regulation of IGF-1 by a family of binding proteins (IGFBPs 1-6), which can either stimulate or inhibit biological action depending on binding; and (4) Circadian patterning and newly discovered variants of glucocorticoid isoforms largely dictating glucocorticoid sensitivity and catabolic, muscle sparing, or pathological influence. The downstream integrated anabolic and catabolic mechanisms of these hormones not only affect the ability of skeletal muscle to generate force; they also have implications for pharmaceutical treatments, aging, and prevalent chronic conditions such as metabolic syndrome, insulin resistance, and hypertension. Thus, advances in our understanding of hormones that impact anabolic: catabolic processes have relevance for athletes and the general population, alike.
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Affiliation(s)
- William J. Kraemer
- Department of Human Sciences, The Ohio State University, Columbus, OH, United States
- *Correspondence: William J. Kraemer
| | - Nicholas A. Ratamess
- Department of Health and Exercise Science, The College of New Jersey, Ewing, NJ, United States
| | - Wesley C. Hymer
- Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, United States
| | - Bradley C. Nindl
- Department of Sports Medicine, School of Health and Rehabilitation Sciences, University of Pittsburgh, Pittsburgh, PA, United States
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92
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Groennebaek T, Sieljacks P, Nielsen R, Pryds K, Jespersen NR, Wang J, Carlsen CR, Schmidt MR, de Paoli FV, Miller BF, Vissing K, Bøtker HE. Effect of Blood Flow Restricted Resistance Exercise and Remote Ischemic Conditioning on Functional Capacity and Myocellular Adaptations in Patients With Heart Failure. Circ Heart Fail 2019; 12:e006427. [PMID: 31830830 DOI: 10.1161/circheartfailure.119.006427] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
BACKGROUND Patients with congestive heart failure (CHF) have impaired functional capacity and inferior quality of life. The clinical manifestations are associated with structural and functional impairments in skeletal muscle, emphasizing a need for feasible rehabilitation strategies beyond optimal anticongestive medical treatment. We investigated whether low-load blood flow restricted resistance exercise (BFRRE) or remote ischemic conditioning (RIC) could improve functional capacity and quality of life in patients with CHF and stimulate skeletal muscle myofibrillar and mitochondrial adaptations. METHODS We randomized 36 patients with CHF to BFRRE, RIC, or nontreatment control. BFRRE and RIC were performed 3× per week for 6 weeks. Before and after intervention, muscle biopsies, tests of functional capacity, and quality of life assessments were performed. Deuterium oxide was administered throughout the intervention to measure cumulative RNA and subfraction protein synthesis. Changes in muscle fiber morphology and mitochondrial respiratory function were also assessed. RESULTS BFRRE improved 6-minute walk test by 39.0 m (CI, 7.0-71.1, P=0.019) compared with control. BFRRE increased maximum isometric strength by 29.7 Nm (CI, 10.8-48.6, P=0.003) compared with control. BFRRE improved quality of life by 5.4 points (CI, -0.04 to 10.9; P=0.052) compared with control. BFRRE increased mitochondrial function by 19.1 pmol/s per milligram (CI, 7.3-30.8; P=0.002) compared with control. RIC did not produce similar changes. CONCLUSIONS Our results demonstrate that BFRRE, but not RIC, improves functional capacity, quality of life, and muscle mitochondrial function. Our findings have clinical implications for rehabilitation of patients with CHF and provide new insights on the myopathy accompanying CHF. CLINICAL TRIAL REGISTRATION URL: https://www.clinicaltrials.gov. Unique identifier: NCT03380663.
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Affiliation(s)
- Thomas Groennebaek
- Section for Sports Science, Department of Public Health, Aarhus University, Aarhus, Denmark (T.G., P.S., J.W., C.R.C., K.V.)
| | - Peter Sieljacks
- Section for Sports Science, Department of Public Health, Aarhus University, Aarhus, Denmark (T.G., P.S., J.W., C.R.C., K.V.)
| | - Roni Nielsen
- Department of Cardiology (R.N., K.P., N.R.J., M.R.S., H.E.B.), Aarhus University Hospital, Denmark
| | - Kasper Pryds
- Department of Cardiology (R.N., K.P., N.R.J., M.R.S., H.E.B.), Aarhus University Hospital, Denmark
| | - Nichlas R Jespersen
- Department of Cardiology (R.N., K.P., N.R.J., M.R.S., H.E.B.), Aarhus University Hospital, Denmark
| | - Jakob Wang
- Section for Sports Science, Department of Public Health, Aarhus University, Aarhus, Denmark (T.G., P.S., J.W., C.R.C., K.V.)
| | - Caroline R Carlsen
- Section for Sports Science, Department of Public Health, Aarhus University, Aarhus, Denmark (T.G., P.S., J.W., C.R.C., K.V.)
| | - Michael R Schmidt
- Department of Cardiology (R.N., K.P., N.R.J., M.R.S., H.E.B.), Aarhus University Hospital, Denmark
| | - Frank V de Paoli
- Department of Biomedicine (F.V.d.P.), Aarhus University Hospital, Denmark.,Department of Cardiothoracic and Vascular Surgery (F.V.d.P.), Aarhus University Hospital, Denmark
| | - Benjamin F Miller
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City (B.F.M.)
| | - Kristian Vissing
- Section for Sports Science, Department of Public Health, Aarhus University, Aarhus, Denmark (T.G., P.S., J.W., C.R.C., K.V.)
| | - Hans Erik Bøtker
- Department of Cardiology (R.N., K.P., N.R.J., M.R.S., H.E.B.), Aarhus University Hospital, Denmark
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93
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Miller BF, Baehr LM, Musci RV, Reid JJ, Peelor FF, Hamilton KL, Bodine SC. Muscle-specific changes in protein synthesis with aging and reloading after disuse atrophy. J Cachexia Sarcopenia Muscle 2019; 10:1195-1209. [PMID: 31313502 PMCID: PMC6903438 DOI: 10.1002/jcsm.12470] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2019] [Revised: 05/09/2019] [Accepted: 06/12/2019] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Successful strategies to halt or reverse sarcopenia require a basic understanding of the factors that cause muscle loss with age. Acute periods of muscle loss in older individuals have an incomplete recovery of muscle mass and strength, thus accelerating sarcopenic progression. The purpose of the current study was to further understand the mechanisms underlying the failure of old animals to completely recover muscle mass and function after a period of hindlimb unloading. METHODS Hindlimb unloading was used to induce muscle atrophy in Fischer 344-Brown Norway (F344BN F1) rats at 24, 28, and 30 months of age. Rats were hindlimb unloaded for 14 days and then reloaded at 24 months (Reloaded 24), 28 months (Reloaded 28), and 24 and 28 months (Reloaded 24/28) of age. Isometric torque was determined at 24 months of age (24 months), at 28 months of age (28 months), immediately after 14 days of reloading, and at 30 months of age (30 months). During control or reloaded conditions, rats were labelled with deuterium oxide (D2 O) to determine rates of muscle protein synthesis and RNA synthesis. RESULTS After 14 days of reloading, in vivo isometric torque returned to baseline in Reloaded 24, but not Reloaded 28 and Reloaded 24/28. Despite the failure of Reloaded 28 and Reloaded 24/28 to regain peak force, all groups were equally depressed in peak force generation at 30 months. Increased age did not decrease muscle protein synthesis rates, and in fact, increased resting rates of protein synthesis were measured in the myofibrillar fraction (Fractional synthesis rate (FSR): %/day) of the plantaris (24 months: 2.53 ± 0.17; 30 months: 3.29 ± 0.17), and in the myofibrillar (24 months: 2.29 ± 0.07; 30 months: 3.34 ± 0.11), collagen (24 months: 1.11 ± 0.07; 30 months: 1.55 ± 0.14), and mitochondrial (24 months: 2.38 ± 0.16; 30 months: 3.20 ± 0.10) fractions of the tibialis anterior (TA). All muscles increased myofibrillar protein synthesis (%/day) in Reloaded 24 (soleus: 3.36 ± 0.11, 5.23 ± 0.19; plantaris: 2.53 ± 0.17, 3.66 ± 0.07; TA: 2.29 ± 0.14, 3.15 ± 0.12); however, in Reloaded 28, only the soleus had myofibrillar protein synthesis rates (%/day) >28 months (28 months: 3.80 ± 0.10; Reloaded 28: 4.86 ± 0.19). Across the muscles, rates of protein synthesis were correlated with RNA synthesis (all muscles combined, R2 = 0.807, P < 0.0001). CONCLUSIONS These data add to the growing body of literature that indicate that changes with age, including following disuse atrophy, differ by muscle. In addition, our findings lead to additional questions of the underlying mechanisms by which some muscles are maintained with age while others are not.
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Affiliation(s)
- Benjamin F Miller
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | - Leslie M Baehr
- Department of Internal Medicine, Endocrinology and Metabolism, University of Iowa Carver College of Medicine, Iowa City, IA, USA
| | - Robert V Musci
- Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, USA
| | - Justin J Reid
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | - Frederick F Peelor
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | - Karyn L Hamilton
- Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, USA
| | - Sue C Bodine
- Department of Internal Medicine, Endocrinology and Metabolism, University of Iowa Carver College of Medicine, Iowa City, IA, USA
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94
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Gharahdaghi N, Rudrappa S, Brook MS, Idris I, Crossland H, Hamrock C, Abdul Aziz MH, Kadi F, Tarum J, Greenhaff PL, Constantin-Teodosiu D, Cegielski J, Phillips BE, Wilkinson DJ, Szewczyk NJ, Smith K, Atherton PJ. Testosterone therapy induces molecular programming augmenting physiological adaptations to resistance exercise in older men. J Cachexia Sarcopenia Muscle 2019; 10:1276-1294. [PMID: 31568675 PMCID: PMC6903447 DOI: 10.1002/jcsm.12472] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Revised: 05/14/2019] [Accepted: 06/12/2019] [Indexed: 01/30/2023] Open
Abstract
BACKGROUND The andropause is associated with declines in serum testosterone (T), loss of muscle mass (sarcopenia), and frailty. Two major interventions purported to offset sarcopenia are anabolic steroid therapies and resistance exercise training (RET). Nonetheless, the efficacy and physiological and molecular impacts of T therapy adjuvant to short-term RET remain poorly defined. METHODS Eighteen non-hypogonadal healthy older men, 65-75 years, were assigned in a random double-blinded fashion to receive, biweekly, either placebo (P, saline, n = 9) or T (Sustanon 250 mg, n = 9) injections over 6 week whole-body RET (three sets of 8-10 repetitions at 80% one-repetition maximum). Subjects underwent dual-energy X-ray absorptiometry, ultrasound of vastus lateralis (VL) muscle architecture, and knee extensor isometric muscle force tests; VL muscle biopsies were taken to quantify myogenic/anabolic gene expression, anabolic signalling, muscle protein synthesis (D2 O), and breakdown (extrapolated). RESULTS Testosterone adjuvant to RET augmented total fat-free mass (P=0.007), legs fat-free mass (P=0.02), and appendicular fat-free mass (P=0.001) gains while decreasing total fat mass (P=0.02). Augmentations in VL muscle thickness, fascicle length, and quadriceps cross-section area with RET occured to a greater extent in T (P < 0.05). Sum strength (P=0.0009) and maximal voluntary contract (e.g. knee extension at 70°) (P=0.002) increased significantly more in the T group. Mechanistically, both muscle protein synthesis rates (T: 2.13 ± 0.21%·day-1 vs. P: 1.34 ± 0.13%·day-1 , P=0.0009) and absolute breakdown rates (T: 140.2 ± 15.8 g·day-1 vs. P: 90.2 ± 11.7 g·day-1 , P=0.02) were elevated with T therapy, which led to higher net turnover and protein accretion in the T group (T: 8.3 ± 1.4 g·day-1 vs. P: 1.9 ± 1.2 g·day-1 , P=0.004). Increases in ribosomal biogenesis (RNA:DNA ratio); mRNA expression relating to T metabolism (androgen receptor: 1.4-fold; Srd5a1: 1.6-fold; AKR1C3: 2.1-fold; and HSD17β3: two-fold); insulin-like growth factor (IGF)-1 signalling [IGF-1Ea (3.5-fold) and IGF-1Ec (three-fold)] and myogenic regulatory factors; and the activity of anabolic signalling (e.g. mTOR, AKT, and RPS6; P < 0.05) were all up-regulated with T therapy. Only T up-regulated mitochondrial citrate synthase activity (P=0.03) and transcription factor A (1.41 ± 0.2-fold, P=0.0002), in addition to peroxisome proliferator-activated receptor-γ co-activator 1-α mRNA (1.19 ± 0.21-fold, P=0.037). CONCLUSIONS Administration of T adjuvant to RET enhanced skeletal muscle mass and performance, while up-regulating myogenic gene programming, myocellular translational efficiency and capacity, collectively resulting in higher protein turnover, and net protein accretion. T coupled with RET is an effective short-term intervention to improve muscle mass/function in older non-hypogonadal men.
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Affiliation(s)
- Nima Gharahdaghi
- MRC-ARUK Centre for Musculoskeletal Ageing Research and Nottingham NIHR BRC, School of Medicine, University of Nottingham, Derby, UK
| | - Supreeth Rudrappa
- MRC-ARUK Centre for Musculoskeletal Ageing Research and Nottingham NIHR BRC, School of Medicine, University of Nottingham, Derby, UK
| | - Matthew S Brook
- MRC-ARUK Centre for Musculoskeletal Ageing Research and Nottingham NIHR BRC, School of Medicine, University of Nottingham, Derby, UK
| | - Iskandar Idris
- MRC-ARUK Centre for Musculoskeletal Ageing Research and Nottingham NIHR BRC, School of Medicine, University of Nottingham, Derby, UK
| | - Hannah Crossland
- MRC-ARUK Centre for Musculoskeletal Ageing Research and Nottingham NIHR BRC, School of Medicine, University of Nottingham, Derby, UK
| | - Claire Hamrock
- Institute of Food and Health, University College Dublin, Belfield, Dublin, Ireland
| | - Muhammad Hariz Abdul Aziz
- MRC-ARUK Centre for Musculoskeletal Ageing Research and Nottingham NIHR BRC, School of Medicine, University of Nottingham, Derby, UK
| | - Fawzi Kadi
- Division of Sports Sciences, School of Health and Medical Sciences, Örebro University, Örebro, Sweden
| | - Janelle Tarum
- Division of Sports Sciences, School of Health and Medical Sciences, Örebro University, Örebro, Sweden
| | - Paul L Greenhaff
- MRC-ARUK Centre for Musculoskeletal Ageing Research, School of Life Sciences, University of Nottingham, Nottingham, Nottingham, UK
| | - Dumitru Constantin-Teodosiu
- MRC-ARUK Centre for Musculoskeletal Ageing Research, School of Life Sciences, University of Nottingham, Nottingham, Nottingham, UK
| | - Jessica Cegielski
- MRC-ARUK Centre for Musculoskeletal Ageing Research and Nottingham NIHR BRC, School of Medicine, University of Nottingham, Derby, UK
| | - Bethan E Phillips
- MRC-ARUK Centre for Musculoskeletal Ageing Research and Nottingham NIHR BRC, School of Medicine, University of Nottingham, Derby, UK
| | - Daniel J Wilkinson
- MRC-ARUK Centre for Musculoskeletal Ageing Research and Nottingham NIHR BRC, School of Medicine, University of Nottingham, Derby, UK
| | - Nathaniel J Szewczyk
- MRC-ARUK Centre for Musculoskeletal Ageing Research and Nottingham NIHR BRC, School of Medicine, University of Nottingham, Derby, UK
| | - Kenneth Smith
- MRC-ARUK Centre for Musculoskeletal Ageing Research and Nottingham NIHR BRC, School of Medicine, University of Nottingham, Derby, UK
| | - Philip J Atherton
- MRC-ARUK Centre for Musculoskeletal Ageing Research and Nottingham NIHR BRC, School of Medicine, University of Nottingham, Derby, UK
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95
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Figueiredo VC. Revisiting the roles of protein synthesis during skeletal muscle hypertrophy induced by exercise. Am J Physiol Regul Integr Comp Physiol 2019; 317:R709-R718. [PMID: 31508978 DOI: 10.1152/ajpregu.00162.2019] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Protein synthesis is deemed the underpinning mechanism enhancing protein balance required for skeletal muscle hypertrophy in response to resistance exercise. The current model of skeletal muscle hypertrophy induced by resistance training states that the acute increase in the rates of protein synthesis after each bout of resistance exercise is the basis for muscle growth. Within this paradigm, each resistance exercise session would add a specific amount of muscle mass; therefore, muscle hypertrophy could be defined as the result of intermittent and short-lived increases in muscle protein synthesis rates following each resistance exercise session. Although a substantial amount of data has accumulated in the last decades regarding the acute changes in protein synthesis (or translational efficiency) following resistance exercise, considerable gaps on the mechanism of muscle growth still exist. Ribosome biogenesis and translational capacity have emerged as important mediators of skeletal muscle hypertrophy. Recent advances in the field have demonstrated that skeletal muscle hypertrophy is associated with markers of translational capacity and long-term changes in protein synthesis under resting conditions. This review will discuss the caveats of the current model of skeletal muscle hypertrophy induced by resistance training while proposing a working model that takes into consideration the novel data generated by independent laboratories utilizing different methodologies. It is argued, herein, that the role of protein synthesis in the current model of muscle hypertrophy warrants revisiting.
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Affiliation(s)
- Vandré Casagrande Figueiredo
- College of Health Sciences, Department of Rehabilitation Sciences, the Center for Muscle Biology, University of Kentucky, Lexington, Kentucky
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96
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McKendry J, Shad BJ, Smeuninx B, Oikawa SY, Wallis G, Greig C, Phillips SM, Breen L. Comparable Rates of Integrated Myofibrillar Protein Synthesis Between Endurance-Trained Master Athletes and Untrained Older Individuals. Front Physiol 2019; 10:1084. [PMID: 31543824 PMCID: PMC6728413 DOI: 10.3389/fphys.2019.01084] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Accepted: 08/07/2019] [Indexed: 12/21/2022] Open
Abstract
Background An impaired muscle anabolic response to exercise and protein nutrition is thought to underpin age-related muscle loss, which may be exacerbated by aspects of biological aging that may not be present in older individuals who have undertaken long-term high-level exercise training, or master athletes (MA). The aim of this study was to compare rested-state and exercise-induced rates of integrated myofibrillar protein synthesis (iMyoPS) and intracellular signaling in endurance trained MA and healthy age-matched untrained individuals (Older Controls). Methods In a parallel study design, iMyoPS rates were determined over 48 h in the rested-state and following a bout of unaccustomed resistance exercise (RE) in OC (n = 8 males; 73.5 ± 3.3 years) and endurance-trained MA (n = 7 males; 68.9 ± 5.7 years). Intramuscular anabolic signaling was also determined. During the iMyoPS measurement period, physical activity was monitored via accelerometry and dietary intake was controlled. Results Anthropometrics, habitual activity, and dietary intake were similar between groups. There was no difference in rested-state rates of iMyoPS between OC (1.47 ± 0.06%⋅day–1) and MA (1.46 ± 0.08%⋅day–1). RE significantly increased iMyoPS above rest in both OC (1.60 ± 0.08%⋅day–1, P < 0.01) and MA (1.61 ± 0.08%⋅day–1, P < 0.01), with no difference between groups. AktThr308 phosphorylation increased at 1 h post-RE in OC (P < 0.05), but not MA. No other between-group differences in intramuscular signaling were apparent at any time-point. Conclusion While our sample size is limited, these data suggest that rested-state and RE-induced iMyoPS are indistinguishable between MA and OC. Importantly, the OC retain a capacity for RE-induced stimulation of skeletal muscle remodeling.
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Affiliation(s)
- James McKendry
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Brandon J Shad
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Benoit Smeuninx
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Sara Y Oikawa
- Department of Kinesiology, McMaster University, Hamilton, ON, Canada
| | - Gareth Wallis
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Carolyn Greig
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, United Kingdom.,NIHR Birmingham Biomedical Research Centre, Birmingham, United Kingdom.,MRC-Arthritis Research UK Centre for Musculoskeletal Ageing Research, University of Birmingham, Birmingham, United Kingdom
| | - Stuart M Phillips
- Department of Kinesiology, McMaster University, Hamilton, ON, Canada
| | - Leigh Breen
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, United Kingdom.,NIHR Birmingham Biomedical Research Centre, Birmingham, United Kingdom.,MRC-Arthritis Research UK Centre for Musculoskeletal Ageing Research, University of Birmingham, Birmingham, United Kingdom
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97
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Hodson N, West DWD, Philp A, Burd NA, Moore DR. Molecular regulation of human skeletal muscle protein synthesis in response to exercise and nutrients: a compass for overcoming age-related anabolic resistance. Am J Physiol Cell Physiol 2019; 317:C1061-C1078. [PMID: 31461340 DOI: 10.1152/ajpcell.00209.2019] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Skeletal muscle mass, a strong predictor of longevity and health in humans, is determined by the balance of two cellular processes, muscle protein synthesis (MPS) and muscle protein breakdown. MPS seems to be particularly sensitive to changes in mechanical load and/or nutritional status; therefore, much research has focused on understanding the molecular mechanisms that underpin this cellular process. Furthermore, older individuals display an attenuated MPS response to anabolic stimuli, termed anabolic resistance, which has a negative impact on muscle mass and function, as well as quality of life. Therefore, an understanding of which, if any, molecular mechanisms contribute to anabolic resistance of MPS is of vital importance in formulation of therapeutic interventions for such populations. This review summarizes the current knowledge of the mechanisms that underpin MPS, which are broadly divided into mechanistic target of rapamycin complex 1 (mTORC1)-dependent, mTORC1-independent, and ribosomal biogenesis-related, and describes the evidence that shows how they are regulated by anabolic stimuli (exercise and/or nutrition) in healthy human skeletal muscle. This review also summarizes evidence regarding which of these mechanisms may be implicated in age-related skeletal muscle anabolic resistance and provides recommendations for future avenues of research that can expand our knowledge of this area.
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Affiliation(s)
- Nathan Hodson
- Faculty of Kinesiology and Physical Education, University of Toronto, Toronto, Ontario, Canada
| | - Daniel W D West
- Faculty of Kinesiology and Physical Education, University of Toronto, Toronto, Ontario, Canada
| | - Andrew Philp
- Garvan Institute of Medical Research, Darlinghurst, Sydney, New South Wales, Australia
| | - Nicholas A Burd
- Department of Kinesiology and Community Health, University of Illinois, Urbana, Illinois
| | - Daniel R Moore
- Faculty of Kinesiology and Physical Education, University of Toronto, Toronto, Ontario, Canada
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98
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Nicoll JX, Fry AC, Mosier EM, Olsen LA, Sontag SA. MAPK, androgen, and glucocorticoid receptor phosphorylation following high-frequency resistance exercise non-functional overreaching. Eur J Appl Physiol 2019; 119:2237-2253. [DOI: 10.1007/s00421-019-04200-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Accepted: 07/29/2019] [Indexed: 12/26/2022]
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99
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Brook MS, Wilkinson DJ, Smith K, Atherton PJ. It's not just about protein turnover: the role of ribosomal biogenesis and satellite cells in the regulation of skeletal muscle hypertrophy. Eur J Sport Sci 2019; 19:952-963. [PMID: 30741116 DOI: 10.1080/17461391.2019.1569726] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Skeletal muscle has indispensable roles in regulating whole body health (e.g. glycemic control, energy consumption) and, in being central in locomotion, is crucial in maintaining quality-of-life. Therefore, understanding the regulation of muscle mass is of significant importance. Resistance exercise training (RET) combined with supportive nutrition is an effective strategy to achieve muscle hypertrophy by driving chronic elevations in muscle protein synthesis (MPS). The regulation of muscle protein synthesis is a coordinated process, in requiring ribosomes to translate mRNA and sufficient myonuclei density to provide the platform for ribosome and mRNA transcription; as such MPS is determined by both translational efficiency (ribosome activity) and translational capacity (ribosome number). Moreover, as the muscle protein pool expands during hypertrophy, translation capacity (i.e. ribosomes and myonuclei content) could theoretically become rate-limiting such that an inability to expand these pools through ribosomal biogenesis and satellite cell (SC) mediated myonuclear addition could limit growth potential. Simple measures of RNA (ribosome content) and DNA (SC/Myonuclei number) concentrations reveal that these pools do increase with hypertrophy; yet whether these adaptations are a pre-requisite or a limiting factor for hypertrophy is unresolved and highly debated. This is primarily due to methodological limitations and many assumptions being made on static measures or correlative associations. However recent advances within the field using stable isotope tracers shows promise in resolving these questions in muscle adaptation.
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Affiliation(s)
- Matthew Stewart Brook
- a MRC-ARUK Centre for Musculoskeletal Ageing Research, University of Nottingham , Derby , UK
- b National Institute for Health Research (NIHR), Nottingham Biomedical Research Centre (BRC), Clinical, Metabolic and Molecular Physiology, University of Nottingham , Derby , UK
| | - Daniel James Wilkinson
- a MRC-ARUK Centre for Musculoskeletal Ageing Research, University of Nottingham , Derby , UK
- b National Institute for Health Research (NIHR), Nottingham Biomedical Research Centre (BRC), Clinical, Metabolic and Molecular Physiology, University of Nottingham , Derby , UK
| | - Ken Smith
- a MRC-ARUK Centre for Musculoskeletal Ageing Research, University of Nottingham , Derby , UK
- b National Institute for Health Research (NIHR), Nottingham Biomedical Research Centre (BRC), Clinical, Metabolic and Molecular Physiology, University of Nottingham , Derby , UK
| | - Philip James Atherton
- a MRC-ARUK Centre for Musculoskeletal Ageing Research, University of Nottingham , Derby , UK
- b National Institute for Health Research (NIHR), Nottingham Biomedical Research Centre (BRC), Clinical, Metabolic and Molecular Physiology, University of Nottingham , Derby , UK
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100
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Chaillou T. Ribosome specialization and its potential role in the control of protein translation and skeletal muscle size. J Appl Physiol (1985) 2019; 127:599-607. [DOI: 10.1152/japplphysiol.00946.2018] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The ribosome is typically viewed as a supramolecular complex with constitutive and invariant capacity in mediating translation of mRNA into protein. This view has been challenged by recent research revealing that ribosome composition could be heterogeneous, and this heterogeneity leads to functional ribosome specialization. This review presents the idea that ribosome heterogeneity results from changes in its various components, including variations in ribosomal protein (RP) composition, posttranslational modifications of RPs, changes in ribosomal-associated proteins, alternative forms of rRNA, and posttranscriptional modifications of rRNAs. Ribosome heterogeneity could be orchestrated at several levels and may depend on numerous factors, such as the subcellular location, cell type, tissue specificity, the development state, cell state, ribosome biogenesis, RP turnover, physiological stimuli, and circadian rhythm. Ribosome specialization represents a completely new concept for the regulation of gene expression. Specialized ribosomes could modulate several aspects of translational control, such as mRNA translation selectivity, translation initiation, translational fidelity, and translation elongation. Recent research indicates that the expression of Rpl3 is markedly increased, while that of Rpl3l is highly reduced during mouse skeletal muscle hypertrophy. Moreover, Rpl3l overexpression impairs the growth and myogenic fusion of myotubes. Although the function of Rpl3 and Rpl3l in the ribosome remains to be clarified, these findings suggest that ribosome specialization may be potentially involved in the control of protein translation and skeletal muscle size. Limited data concerning ribosome specialization are currently available in skeletal muscle. Future investigations have the potential to delineate the function of specialized ribosomes in skeletal muscle.
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Affiliation(s)
- Thomas Chaillou
- School of Health Sciences, Örebro University, Örebro, Sweden
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