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He W, Connolly ED, Cross HR, Wu G. Dietary protein and amino acid intakes for mitigating sarcopenia in humans. Crit Rev Food Sci Nutr 2024:1-24. [PMID: 38803274 DOI: 10.1080/10408398.2024.2348549] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
Adult humans generally experience a 0.5-1%/year loss in whole-body skeletal muscle mass and a reduction of muscle strength by 1.5-5%/year beginning at the age of 50 years. This results in sarcopenia (aging-related progressive losses of skeletal muscle mass and strength) that affects 10-16% of adults aged ≥ 60 years worldwide. Concentrations of some amino acids (AAs) such as branched-chain AAs, arginine, glutamine, glycine, and serine are reduced in the plasma of older than young adults likely due to insufficient protein intake, reduced protein digestibility, and increased AA catabolism by the portal-drained viscera. Acute, short-term, or long-term administration of some of these AAs or a mixture of proteinogenic AAs can enhance blood flow to skeletal muscle, activate the mechanistic target of rapamycin cell signaling pathway for the initiation of muscle protein synthesis, and modulate the metabolic activity of the muscle. In addition, some AA metabolites such as taurine, β-alanine, carnosine, and creatine have similar physiological effects on improving muscle mass and function in older adults. Long-term adequate intakes of protein and the AA metabolites can aid in mitigating sarcopenia in elderly adults. Appropriate combinations of animal- and plant-sourced foods are most desirable to maintain proper dietary AA balance.
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Affiliation(s)
- Wenliang He
- Department of Animal Science, Texas A&M University, College Station, TX, USA
| | - Erin D Connolly
- Department of Animal Science, Texas A&M University, College Station, TX, USA
| | - H Russell Cross
- Department of Animal Science, Texas A&M University, College Station, TX, USA
| | - Guoyao Wu
- Department of Animal Science, Texas A&M University, College Station, TX, USA
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2
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Liao S, Zhao L, Huang C, Xiong A, Xiong W, He Y, Huang X, Hunter V, Luo B. One-year trajectories of nutritional status in perimenopausal women: a community-based multi-centered prospective study. BMC Public Health 2024; 24:914. [PMID: 38549103 PMCID: PMC10976711 DOI: 10.1186/s12889-024-18405-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2023] [Accepted: 03/20/2024] [Indexed: 04/01/2024] Open
Abstract
BACKGROUND Nutritional status is a modifiable factor associated with perimenopausal women's health and quality of life. Assessing body composition indicators helps to comprehensively understand nutritional status compared with using body mass index (BMI) only. However, few published studies measured the trends in body composition among perimenopausal women. OBJECTIVES To assess the one-year trajectory of the nutritional status of perimenopausal women and to explore its influential factors. METHODS A community-based observational study with 3-wave repeated measurements at 6-month intervals was carried out. The nutritional status indicators include weight, body mass index (BMI), and body composition variables. Bioelectrical impedance analysis was used to assess body composition. Repeated measures ANOVA and Chi-square test were used to calculate the changes in nutritional status and generalized estimating equations were performed to explore their influential factors. RESULTS 2760 participants completed the study. Increasing trajectories in weight (from 56.05 ± 7.55 to 57.02 ± 7.60), fat mass (from 17.99 ± 4.80 to 20.49 ± 4.90), and waist-hip ratio (from 0.86 ± 0.04 to 0.91 ± 0.15) were found (P < 0.001). Decreasing trajectories in skeletal muscle (from 20.30 ± 2.38 to 19.19 ± 2.46), protein level (from 7.39 ± 0.79 to 7.06 ± 0.81), and total body water (from 27.87 ± 2.92 to 27.00 ± 3.01) were found (P < 0.001). Being married/unmarried with a partner and without negative life events were associated with higher total body water, skeletal muscle, and protein level, while negatively associated with fat mass and waist-hip ratio. Age was positively associated with fat mass (P < 0.001). Participants with junior high school education were prone to increased fat mass (P = 0.018) compared with those holding primary school education and below. A per capita monthly income of 1500 to 3000 Yuan was associated with higher total body water, skeletal muscle, and protein level (P < 0.001) compared with a per capita monthly income of less than 1500 Yuan. CONCLUSION Worsening nutritional status exists in perimenopausal women, which is characterized by increased weight, fat mass, and waist-hip ratio, and decreased skeletal muscle, total body water, and protein level. For greater efficiency, precision nutritional interventions are needed, and recipients should be classified into different risk levels based on their sociodemographic background.
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Affiliation(s)
- Shujuan Liao
- Department of Nursing, West China Second University Hospital, Sichuan University, No. 20, Section 3, People's South Road, 610041, Chengdu, Sichuan, China
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Sichuan University, Ministry of Education, Chengdu, Sichuan, China
| | - Li Zhao
- Department of Health Policy and Management, West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Chuanya Huang
- Department of Nursing, West China Second University Hospital, Sichuan University, No. 20, Section 3, People's South Road, 610041, Chengdu, Sichuan, China
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Sichuan University, Ministry of Education, Chengdu, Sichuan, China
| | - Anqi Xiong
- Department of Nursing, West China Second University Hospital, Sichuan University, No. 20, Section 3, People's South Road, 610041, Chengdu, Sichuan, China
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Sichuan University, Ministry of Education, Chengdu, Sichuan, China
| | - Weijun Xiong
- Chengdu Zhongke Zhiyong Information Technology Co., LTD, Chengdu, Sichuan, China
| | - Yirong He
- Department of Nursing, West China Second University Hospital, Sichuan University, No. 20, Section 3, People's South Road, 610041, Chengdu, Sichuan, China
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Sichuan University, Ministry of Education, Chengdu, Sichuan, China
| | | | | | - Biru Luo
- Department of Nursing, West China Second University Hospital, Sichuan University, No. 20, Section 3, People's South Road, 610041, Chengdu, Sichuan, China.
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Sichuan University, Ministry of Education, Chengdu, Sichuan, China.
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3
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Tezze C, Sandri M, Tessari P. Anabolic Resistance in the Pathogenesis of Sarcopenia in the Elderly: Role of Nutrition and Exercise in Young and Old People. Nutrients 2023; 15:4073. [PMID: 37764858 PMCID: PMC10535169 DOI: 10.3390/nu15184073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Revised: 09/01/2023] [Accepted: 09/03/2023] [Indexed: 09/29/2023] Open
Abstract
The development of sarcopenia in the elderly is associated with many potential factors and/or processes that impair the renovation and maintenance of skeletal muscle mass and strength as ageing progresses. Among them, a defect by skeletal muscle to respond to anabolic stimuli is to be considered. Common anabolic stimuli/signals in skeletal muscle are hormones (insulin, growth hormones, IGF-1, androgens, and β-agonists such epinephrine), substrates (amino acids such as protein precursors on top, but also glucose and fat, as source of energy), metabolites (such as β-agonists and HMB), various biochemical/intracellular mediators), physical exercise, neurogenic and immune-modulating factors, etc. Each of them may exhibit a reduced effect upon skeletal muscle in ageing. In this article, we overview the role of anabolic signals on muscle metabolism, as well as currently available evidence of resistance, at the skeletal muscle level, to anabolic factors, from both in vitro and in vivo studies. Some indications on how to augment the effects of anabolic signals on skeletal muscle are provided.
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Affiliation(s)
- Caterina Tezze
- Department of Biomedical Sciences, University of Padova, via Ugo Bassi 58/b, 35121 Padova, Italy;
- Veneto Institute of Molecular Medicine, via Orus 2, 35129 Padova, Italy
| | - Marco Sandri
- Department of Biomedical Sciences, University of Padova, via Ugo Bassi 58/b, 35121 Padova, Italy;
- Veneto Institute of Molecular Medicine, via Orus 2, 35129 Padova, Italy
- Department of Medicine, McGill University, Montreal, QC H4A 3J1, Canada
| | - Paolo Tessari
- Department of Medicine, University of Padova, via Giustiniani 2, 35128 Padova, Italy
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4
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Kubat GB, Bouhamida E, Ulger O, Turkel I, Pedriali G, Ramaccini D, Ekinci O, Ozerklig B, Atalay O, Patergnani S, Nur Sahin B, Morciano G, Tuncer M, Tremoli E, Pinton P. Mitochondrial dysfunction and skeletal muscle atrophy: Causes, mechanisms, and treatment strategies. Mitochondrion 2023; 72:33-58. [PMID: 37451353 DOI: 10.1016/j.mito.2023.07.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Revised: 07/02/2023] [Accepted: 07/11/2023] [Indexed: 07/18/2023]
Abstract
Skeletal muscle, which accounts for approximately 40% of total body weight, is one of the most dynamic and plastic tissues in the human body and plays a vital role in movement, posture and force production. More than just a component of the locomotor system, skeletal muscle functions as an endocrine organ capable of producing and secreting hundreds of bioactive molecules. Therefore, maintaining healthy skeletal muscles is crucial for supporting overall body health. Various pathological conditions, such as prolonged immobilization, cachexia, aging, drug-induced toxicity, and cardiovascular diseases (CVDs), can disrupt the balance between muscle protein synthesis and degradation, leading to skeletal muscle atrophy. Mitochondrial dysfunction is a major contributing mechanism to skeletal muscle atrophy, as it plays crucial roles in various biological processes, including energy production, metabolic flexibility, maintenance of redox homeostasis, and regulation of apoptosis. In this review, we critically examine recent knowledge regarding the causes of muscle atrophy (disuse, cachexia, aging, etc.) and its contribution to CVDs. Additionally, we highlight the mitochondrial signaling pathways involvement to skeletal muscle atrophy, such as the ubiquitin-proteasome system, autophagy and mitophagy, mitochondrial fission-fusion, and mitochondrial biogenesis. Furthermore, we discuss current strategies, including exercise, mitochondria-targeted antioxidants, in vivo transfection of PGC-1α, and the potential use of mitochondrial transplantation as a possible therapeutic approach.
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Affiliation(s)
- Gokhan Burcin Kubat
- Department of Mitochondria and Cellular Research, Gulhane Health Sciences Institute, University of Health Sciences, 06010 Ankara, Turkey.
| | - Esmaa Bouhamida
- Translational Research Center, Maria Cecilia Hospital GVM Care & Research, 48033 Cotignola, Italy
| | - Oner Ulger
- Department of Mitochondria and Cellular Research, Gulhane Health Sciences Institute, University of Health Sciences, 06010 Ankara, Turkey
| | - Ibrahim Turkel
- Department of Exercise and Sport Sciences, Faculty of Sport Sciences, Hacettepe University, 06800 Ankara, Turkey
| | - Gaia Pedriali
- Translational Research Center, Maria Cecilia Hospital GVM Care & Research, 48033 Cotignola, Italy
| | - Daniela Ramaccini
- Translational Research Center, Maria Cecilia Hospital GVM Care & Research, 48033 Cotignola, Italy
| | - Ozgur Ekinci
- Department of Pathology, Gazi University, 06500 Ankara, Turkey
| | - Berkay Ozerklig
- Department of Exercise and Sport Sciences, Faculty of Sport Sciences, Hacettepe University, 06800 Ankara, Turkey
| | - Ozbeyen Atalay
- Department of Physiology, Faculty of Medicine, Hacettepe University, 06230 Ankara, Turkey
| | - Simone Patergnani
- Translational Research Center, Maria Cecilia Hospital GVM Care & Research, 48033 Cotignola, Italy; Department of Medical Sciences, Laboratory for Technologies of Advanced Therapies (LTTA), University of Ferrara, 44121 Ferrara, Italy
| | - Beyza Nur Sahin
- Department of Physiology, Faculty of Medicine, Hacettepe University, 06230 Ankara, Turkey
| | - Giampaolo Morciano
- Translational Research Center, Maria Cecilia Hospital GVM Care & Research, 48033 Cotignola, Italy; Department of Medical Sciences, Laboratory for Technologies of Advanced Therapies (LTTA), University of Ferrara, 44121 Ferrara, Italy
| | - Meltem Tuncer
- Department of Physiology, Faculty of Medicine, Hacettepe University, 06230 Ankara, Turkey
| | - Elena Tremoli
- Translational Research Center, Maria Cecilia Hospital GVM Care & Research, 48033 Cotignola, Italy
| | - Paolo Pinton
- Translational Research Center, Maria Cecilia Hospital GVM Care & Research, 48033 Cotignola, Italy; Department of Medical Sciences, Laboratory for Technologies of Advanced Therapies (LTTA), University of Ferrara, 44121 Ferrara, Italy.
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5
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Kim JY, Kwon YG, Kim YM. The stress-responsive protein REDD1 and its pathophysiological functions. Exp Mol Med 2023; 55:1933-1944. [PMID: 37653030 PMCID: PMC10545776 DOI: 10.1038/s12276-023-01056-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2023] [Revised: 05/13/2023] [Accepted: 05/17/2023] [Indexed: 09/02/2023] Open
Abstract
Regulated in development and DNA damage-response 1 (REDD1) is a stress-induced protein that controls various cellular functions, including metabolism, oxidative stress, autophagy, and cell fate, and contributes to the pathogenesis of metabolic and inflammatory disorders, neurodegeneration, and cancer. REDD1 usually exerts deleterious effects, including tumorigenesis, metabolic inflammation, neurodegeneration, and muscle dystrophy; however, it also exhibits protective functions by regulating multiple intrinsic cell activities through either an mTORC1-dependent or -independent mechanism. REDD1 typically regulates mTORC1 signaling, NF-κB activation, and cellular pro-oxidant or antioxidant activity by interacting with 14-3-3 proteins, IκBα, and thioredoxin-interacting protein or 75 kDa glucose-regulated protein, respectively. The diverse functions of REDD1 depend on cell type, cellular context, interaction partners, and cellular localization (e.g., mitochondria, endomembrane, or cytosol). Therefore, comprehensively understanding the molecular mechanisms and biological roles of REDD1 under pathophysiological conditions is of utmost importance. In this review, based on the published literature, we highlight and discuss the molecular mechanisms underlying the REDD1 expression and its actions, biological functions, and pathophysiological roles.
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Affiliation(s)
- Ji-Yoon Kim
- Department of Anesthesiology and Pain Medicine, Hanyang University Hospital, Seoul, 04763, Republic of Korea
| | - Young-Guen Kwon
- Department of Biochemistry, College of Life Science and Biotechnology, Yonsei University, Seoul, 03722, Republic of Korea
| | - Young-Myeong Kim
- Department of Molecular and Cellular Biochemistry, School of Medicine, Kangwon National University, Chuncheon, 24341, Republic of Korea.
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6
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de Jong JCBC, Attema BJ, van der Hoek MD, Verschuren L, Caspers MPM, Kleemann R, van der Leij FR, van den Hoek AM, Nieuwenhuizen AG, Keijer J. Sex differences in skeletal muscle-aging trajectory: same processes, but with a different ranking. GeroScience 2023; 45:2367-2386. [PMID: 36820956 PMCID: PMC10651666 DOI: 10.1007/s11357-023-00750-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2022] [Accepted: 02/02/2023] [Indexed: 02/24/2023] Open
Abstract
Sex differences in muscle aging are poorly understood, but could be crucial for the optimization of sarcopenia-related interventions. To gain insight into potential sex differences in muscle aging, we recruited young (23 ± 2 years, 13 males and 13 females) and old (80 ± 3.5 years, 28 males and 26 females) participants. Males and females in both groups were highly matched, and vastus lateralis muscle parameters of old versus young participants were compared for each sex separately, focusing on gene expression. The overall gene expression profiles separated the sexes, but similar gene expression patterns separated old from young participants in males and females. Genes were indeed regulated in the same direction in both sexes during aging; however, the magnitude of differential expression was sex specific. In males, oxidative phosphorylation was the top-ranked differentially expressed process, and in females, this was cell growth mediated by AKT signaling. Findings from RNA-seq data were studied in greater detail using alternative approaches. In addition, we confirmed our data using publicly available data from three independent human studies. In conclusion, top-ranked pathways differ between males and females, but were present and altered in the same direction in both sexes. We conclude that the same processes are associated with skeletal muscle aging in males and females, but the differential expression of those processes in old vs. young participants is sex specific.
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Affiliation(s)
- Jelle C B C de Jong
- Human and Animal Physiology, Wageningen University, 6700AH, Wageningen, The Netherlands
- Department of Metabolic Health Research, The Netherlands Organization for Applied Scientific Research (TNO), Leiden, The Netherlands
| | - Brecht J Attema
- Human and Animal Physiology, Wageningen University, 6700AH, Wageningen, The Netherlands
| | - Marjanne D van der Hoek
- Human and Animal Physiology, Wageningen University, 6700AH, Wageningen, The Netherlands
- Applied Research Centre Food and Dairy, Van Hall Larenstein University of Applied Sciences, Leeuwarden, The Netherlands
- MCL Academy, Medical Centre Leeuwarden, Leeuwarden, The Netherlands
| | - Lars Verschuren
- Department of Microbiology and Systems Biology, The Netherlands Organization for Applied Scientific Research (TNO), Zeist, The Netherlands
| | - Martien P M Caspers
- Department of Microbiology and Systems Biology, The Netherlands Organization for Applied Scientific Research (TNO), Zeist, The Netherlands
| | - Robert Kleemann
- Department of Metabolic Health Research, The Netherlands Organization for Applied Scientific Research (TNO), Leiden, The Netherlands
| | - Feike R van der Leij
- Applied Research Centre Food and Dairy, Van Hall Larenstein University of Applied Sciences, Leeuwarden, The Netherlands
- Research and Innovation Centre Agri, Food & Life Sciences, Inholland University of Applied Sciences, Delft and Amsterdam, The Netherlands
| | - Anita M van den Hoek
- Department of Metabolic Health Research, The Netherlands Organization for Applied Scientific Research (TNO), Leiden, The Netherlands
| | - Arie G Nieuwenhuizen
- Human and Animal Physiology, Wageningen University, 6700AH, Wageningen, The Netherlands
| | - Jaap Keijer
- Human and Animal Physiology, Wageningen University, 6700AH, Wageningen, The Netherlands.
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7
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Chaillou T, Montiel-Rojas D. Does the blunted stimulation of skeletal muscle protein synthesis by aging in response to mechanical load result from impaired ribosome biogenesis? FRONTIERS IN AGING 2023; 4:1171850. [PMID: 37256189 PMCID: PMC10225510 DOI: 10.3389/fragi.2023.1171850] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Accepted: 05/04/2023] [Indexed: 06/01/2023]
Abstract
Age-related loss of skeletal muscle mass leads to a reduction of strength. It is likely due to an inadequate stimulation of muscle protein synthesis (MPS) in response to anabolic stimuli, such as mechanical load. Ribosome biogenesis is a major determinant of translational capacity and is essential for the control of muscle mass. This mini-review aims to put forth the hypothesis that ribosome biogenesis is impaired by aging in response to mechanical load, which could contribute to the age-related anabolic resistance and progressive muscle atrophy. Recent animal studies indicate that aging impedes muscle hypertrophic response to mechanical overload. This is associated with an impaired transcription of ribosomal DNA (rDNA) by RNA polymerase I (Pol I), a limited increase in total RNA concentration, a blunted activation of AKT/mTOR pathway, and an increased phosphorylation of AMPK. In contrast, an age-mediated impairment of ribosome biogenesis is unlikely in response to electrical stimulations. In human, the hypertrophic response to resistance exercise training is diminished with age. This is accompanied by a deficit in long-term MPS and an absence of increased total RNA concentration. The results addressing the acute response to resistance exercise suggest an impaired Pol I-mediated rDNA transcription and attenuated activation/expression of several upstream regulators of ribosome biogenesis in muscles from aged individuals. Altogether, emerging evidence indicates that impaired ribosome biogenesis could partly explain age-related anabolic resistance to mechanical load, which may ultimately contribute to progressive muscle atrophy. Future research should develop more advanced molecular tools to provide in-depth analysis of muscle ribosome biogenesis.
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8
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Guimera AM, Clark P, Wordsworth J, Anugula S, Rasmussen LJ, Shanley DP. Systems modelling predicts chronic inflammation and genomic instability prevent effective mitochondrial regulation during biological ageing. Exp Gerontol 2022; 166:111889. [PMID: 35811018 DOI: 10.1016/j.exger.2022.111889] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 06/30/2022] [Accepted: 07/04/2022] [Indexed: 11/15/2022]
Abstract
The regulation of mitochondrial turnover under conditions of stress occurs partly through the AMPK-NAD+-PGC1α-SIRT1 signalling pathway. This pathway can be affected by both genomic instability and chronic inflammation since these will result in an increased rate of NAD+ degradation through PARP1 and CD38 respectively. In this work we develop a computational model of this signalling pathway, calibrating and validating it against experimental data. The computational model is used to study mitochondrial turnover under conditions of stress and how it is affected by genomic instability, chronic inflammation and biological ageing in general. We report that the AMPK-NAD+-PGC1α-SIRT1 signalling pathway becomes less responsive with age and that this can prime for the accumulation of dysfunctional mitochondria.
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Affiliation(s)
- Alvaro Martinez Guimera
- Biosciences Institute, Ageing Research Laboratories, Campus for Ageing and Vitality, Newcastle University, United Kingdom
| | - Peter Clark
- Biosciences Institute, Ageing Research Laboratories, Campus for Ageing and Vitality, Newcastle University, United Kingdom
| | - James Wordsworth
- Biosciences Institute, Ageing Research Laboratories, Campus for Ageing and Vitality, Newcastle University, United Kingdom
| | - Sharath Anugula
- Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Lene Juel Rasmussen
- Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Daryl P Shanley
- Biosciences Institute, Ageing Research Laboratories, Campus for Ageing and Vitality, Newcastle University, United Kingdom.
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9
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Buckinx F, Aubertin-Leheudre M. Sarcopenia in Menopausal Women: Current Perspectives. Int J Womens Health 2022; 14:805-819. [PMID: 35769543 PMCID: PMC9235827 DOI: 10.2147/ijwh.s340537] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Accepted: 06/09/2022] [Indexed: 12/15/2022] Open
Abstract
Menopause is associated with hormonal changes, which could accelerate or lead to sarcopenia. Functional impairment and physical disability are the major consequences of sarcopenia. In order to hamper these negative health outcomes, it appears necessary to prevent and even treat sarcopenia, through healthy lifestyle changes including diet and regular physical activity or through hormonal replacement therapy when appropriate. Therefore, the purpose of this narrative review will be 1) to present the prevalence of sarcopenia in postmenopausal women; 2) to address the risk factors related to sarcopenia in this specific population; and 3) to discuss how to manage sarcopenia among postmenopausal women.
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Affiliation(s)
- Fanny Buckinx
- Département des Sciences de l'Activité Physique, Groupe de Recherche en Activité Physique Adapté, Université du Québec à Montréal (UQAM), Montréal (Qc), Canada.,Centre de Recherche de l'Institut Universitaire de Gériatrie de Montréal (CRIUGM), Montréal (Qc), Canada
| | - Mylène Aubertin-Leheudre
- Département des Sciences de l'Activité Physique, Groupe de Recherche en Activité Physique Adapté, Université du Québec à Montréal (UQAM), Montréal (Qc), Canada.,Centre de Recherche de l'Institut Universitaire de Gériatrie de Montréal (CRIUGM), Montréal (Qc), Canada
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10
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Bell LR, Gabbett TJ, Davis GM, Wallen MP, O’Brien BJ. Stubborn Exercise Responders-Where to Next? Sports (Basel) 2022; 10:sports10060095. [PMID: 35736835 PMCID: PMC9229615 DOI: 10.3390/sports10060095] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2022] [Revised: 06/03/2022] [Accepted: 06/08/2022] [Indexed: 11/17/2022] Open
Abstract
There is a wide variance in the magnitude of physiological adaptations after resistance or endurance training. The incidence of “non” or “poor” responders to training has been reported to represent as high as 40% of the project’s sample. However, the incidence of poor responders to training can be ameliorated with manipulation of either the training frequency, intensity, type and duration. Additionally, global non-response to cardio-respiratory fitness training is eliminated when evaluating several health measures beyond just the target variables as at least one or more measure improves. More research is required to determine if altering resistance training variables results in a more favourable response in individuals with an initial poor response to resistance training. Moreover, we recommend abandoning the term “poor” responders, as ultimately the magnitude of change in cardiorespiratory fitness in response to endurance training is similar in “poor” and “high” responders if the training frequency is subsequently increased. Therefore, we propose “stubborn” responders as a more appropriate term. Future research should focus on developing viable physiological and lifestyle screening tests that identify likely stubborn responders to conventional exercise training guidelines before the individual engages with training. Exerkines, DNA damage, metabolomic responses in blood, saliva and breath, gene sequence, gene expression and epigenetics are candidate biomarkers that warrant investigation into their relationship with trainability. Crucially, viable biomarker screening tests should show good construct validity to distinguish between different exercise loads, and possess excellent sensitivity and reliability. Furthermore “red flag” tests of likely poor responders to training should be practical to assess in clinical settings and be affordable and non-invasive. Early identification of stubborn responders would enable optimization of training programs from the onset of training to maintain exercise motivation and optimize the impact on training adaptations and health.
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Affiliation(s)
- Leo R. Bell
- Institute of Health and Wellbeing, Federation University, Mount Helen, VIC 3350, Australia; (L.R.B.); (T.J.G.); (G.M.D.); (M.P.W.)
| | - Tim J. Gabbett
- Institute of Health and Wellbeing, Federation University, Mount Helen, VIC 3350, Australia; (L.R.B.); (T.J.G.); (G.M.D.); (M.P.W.)
- Gabbett Performance Solutions, Brisbane, QLD 4011, Australia
| | - Gregory M. Davis
- Institute of Health and Wellbeing, Federation University, Mount Helen, VIC 3350, Australia; (L.R.B.); (T.J.G.); (G.M.D.); (M.P.W.)
| | - Matthew P. Wallen
- Institute of Health and Wellbeing, Federation University, Mount Helen, VIC 3350, Australia; (L.R.B.); (T.J.G.); (G.M.D.); (M.P.W.)
- Caring Futures Institute, College of Nursing and Health Sciences, Flinders University, Adelaide, SA 5000, Australia
| | - Brendan J. O’Brien
- Institute of Health and Wellbeing, Federation University, Mount Helen, VIC 3350, Australia; (L.R.B.); (T.J.G.); (G.M.D.); (M.P.W.)
- Correspondence:
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11
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Sadria M, Seo D, Layton AT. The mixed blessing of AMPK signaling in Cancer treatments. BMC Cancer 2022; 22:105. [PMID: 35078427 PMCID: PMC8786626 DOI: 10.1186/s12885-022-09211-1] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Accepted: 01/17/2022] [Indexed: 12/19/2022] Open
Abstract
Background Nutrient acquisition and metabolism pathways are altered in cancer cells to meet bioenergetic and biosynthetic demands. A major regulator of cellular metabolism and energy homeostasis, in normal and cancer cells, is AMP-activated protein kinase (AMPK). AMPK influences cell growth via its modulation of the mechanistic target of Rapamycin (mTOR) pathway, specifically, by inhibiting mTOR complex mTORC1, which facilitates cell proliferation, and by activating mTORC2 and cell survival. Given its conflicting roles, the effects of AMPK activation in cancer can be counter intuitive. Prior to the establishment of cancer, AMPK acts as a tumor suppressor. However, following the onset of cancer, AMPK has been shown to either suppress or promote cancer, depending on cell type or state. Methods To unravel the controversial roles of AMPK in cancer, we developed a computational model to simulate the effects of pharmacological maneuvers that target key metabolic signalling nodes, with a specific focus on AMPK, mTORC, and their modulators. Specifically, we constructed an ordinary differential equation-based mechanistic model of AMPK-mTORC signaling, and parametrized the model based on existing experimental data. Results Model simulations were conducted to yield the following predictions: (i) increasing AMPK activity has opposite effects on mTORC depending on the nutrient availability; (ii) indirect inhibition of AMPK activity through inhibition of sirtuin 1 (SIRT1) only has an effect on mTORC activity under conditions of low nutrient availability; (iii) the balance between cell proliferation and survival exhibits an intricate dependence on DEP domain-containing mTOR-interacting protein (DEPTOR) abundance and AMPK activity; (iv) simultaneous direct inhibition of mTORC2 and activation of AMPK is a potential strategy for suppressing both cell survival and proliferation. Conclusions Taken together, model simulations clarify the competing effects and the roles of key metabolic signalling pathways in tumorigenesis, which may yield insights on innovative therapeutic strategies. Supplementary Information The online version contains supplementary material available at 10.1186/s12885-022-09211-1.
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Rivas DA, Peng F, Benard T, Ramos da Silva AS, Fielding RA, Margolis LM. miR-19b-3p is associated with a diametric response to resistance exercise in older adults and regulates skeletal muscle anabolism via PTEN inhibition. Am J Physiol Cell Physiol 2021; 321:C977-C991. [PMID: 34705586 PMCID: PMC8714992 DOI: 10.1152/ajpcell.00190.2021] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Understanding paradoxical responses to anabolic stimulation and identifying the mechanisms for this inconsistency in mobility-limited older adults may provide new targets for the treatment of sarcopenia. Our laboratory has discovered that dysregulation in microRNA (miRNA) that target anabolic pathways is a potential mechanism resulting in age-associated decreases in skeletal muscle mass and function (sarcopenia). The objective of the current study was to assess circulating miRNA expression profiles in diametric response of leg lean mass in mobility-limited older individuals after a 6-mo progressive resistance exercise training intervention (PRET) and determine the influence of differentially expressing miRNA on regulation of skeletal muscle mass. Participants were dichotomized by gain (Gainers; mean +561.4 g, n = 33) or loss (Losers; mean −589.8 g, n = 40) of leg lean mass after PRET. Gainers significantly increased fat-free mass 2.4% vs. −0.4% for Losers. Six miRNA (miR-1-3p, miR-19b-3p, miR-92a, miR-126, miR-133a-3p, and miR-133b) were significantly identified to be differentially expressed between Gainers and Losers, with miR-19b-3p being the miRNA most highly associated with increases in fat-free mass. Using an aging mouse model, we then assessed if miR-19b-3p expression was different in young mice with larger muscle mass compared with older mice. Circulating and skeletal muscle miR-19b-3p expression was higher in young compared with old mice and was positively associated with muscle mass and grip strength. We then used a novel integrative approach to determine if differences in circulating miR-19b-3p potentially translate to augmented anabolic response in human skeletal muscle cells in vitro. Results from this analysis identified that overexpression of miR-19b-3p targeted and downregulated PTEN by 64% to facilitate significant ∼50% increase in muscle protein synthetic rate as measured with SUnSET. The combine results of these three models identify miR-19b-3p as a potent regulator of muscle anabolism that may contribute to an inter-individual response to PRET in mobility-limited older adults.
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Affiliation(s)
- Donato A Rivas
- Nutrition, Exercise Physiology and Sarcopenia Laboratory; Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University, Boston, MA, United States
| | - Fei Peng
- Nutrition, Exercise Physiology and Sarcopenia Laboratory; Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University, Boston, MA, United States
| | - Townsend Benard
- Nutrition, Exercise Physiology and Sarcopenia Laboratory; Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University, Boston, MA, United States
| | - Adelino Sanchez Ramos da Silva
- Nutrition, Exercise Physiology and Sarcopenia Laboratory; Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University, Boston, MA, United States.,School of Physical Education and Sport of Ribeirao Preto, University of Sao Paulo, Ribeirao Preto, Sao Paulo, Brazil
| | - Roger A Fielding
- Nutrition, Exercise Physiology and Sarcopenia Laboratory; Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University, Boston, MA, United States
| | - Lee M Margolis
- Nutrition, Exercise Physiology and Sarcopenia Laboratory; Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University, Boston, MA, United States.,Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA, United States
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Sadri S, Sharifi G, Jalali Dehkordi K. Nano branched-chain amino acids enhance the effect of uphill (concentric) and downhill (eccentric) treadmill exercise on muscle gene expression of Akt and mTOR on aged rats. SPORT SCIENCES FOR HEALTH 2021. [DOI: 10.1007/s11332-021-00828-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Silva TR, Oppermann K, Reis FM, Spritzer PM. Nutrition in Menopausal Women: A Narrative Review. Nutrients 2021; 13:nu13072149. [PMID: 34201460 PMCID: PMC8308420 DOI: 10.3390/nu13072149] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Revised: 06/16/2021] [Accepted: 06/18/2021] [Indexed: 12/12/2022] Open
Abstract
Among the various aspects of health promotion and lifestyle adaptation to the postmenopausal period, nutritional habits are essential because they concern all women, can be modified, and impact both longevity and quality of life. In this narrative review, we discuss the current evidence on the association between dietary patterns and clinical endpoints in postmenopausal women, such as body composition, bone mass, and risk markers for cardiovascular disease. Current evidence suggests that low-fat, plant-based diets are associated with beneficial effects on body composition, but further studies are needed to confirm these results in postmenopausal women. The Mediterranean diet pattern along with other healthy habits may help the primary prevention of bone, metabolic, and cardiovascular diseases in the postmenopausal period. It consists on the use of healthy foods that have anti-inflammatory and antioxidant properties, and is associated with a small but significant decrease in blood pressure, reduction of fat mass, and improvement in cholesterol levels. These effects remain to be evaluated over a longer period of time, with the assessment of hard outcomes such as bone fractures, diabetes, and coronary ischemia.
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Affiliation(s)
- Thais R. Silva
- Gynecological Endocrinology Unit, Division of Endocrinology, Hospital de Clínicas de Porto Alegre, Rua Ramiro Barcelos 2350, Porto Alegre 90035-003, Brazil;
- Laboratory of Molecular Endocrinology, Department of Physiology, Federal University of Rio Grande do Sul, Porto Alegre 90035-003, Brazil
| | - Karen Oppermann
- Medical School of Universidade de Passo Fundo, São Vicente de Paulo Hospital, Passo Fundo 99052-900, Brazil;
| | - Fernando M. Reis
- Division of Human Reproduction, Hospital das Clínicas, Department of Obstetrics and Gynecology, Universidade Federal de Minas Gerais, Belo Horizonte 30130-100, Brazil
- Correspondence: (F.M.R.); (P.M.S.); Tel.: +55-51-3359-8027 (P.M.S.)
| | - Poli Mara Spritzer
- Gynecological Endocrinology Unit, Division of Endocrinology, Hospital de Clínicas de Porto Alegre, Rua Ramiro Barcelos 2350, Porto Alegre 90035-003, Brazil;
- Laboratory of Molecular Endocrinology, Department of Physiology, Federal University of Rio Grande do Sul, Porto Alegre 90035-003, Brazil
- Correspondence: (F.M.R.); (P.M.S.); Tel.: +55-51-3359-8027 (P.M.S.)
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Sadria M, Layton AT. Interactions among mTORC, AMPK and SIRT: a computational model for cell energy balance and metabolism. Cell Commun Signal 2021; 19:57. [PMID: 34016143 PMCID: PMC8135154 DOI: 10.1186/s12964-021-00706-1] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 01/11/2021] [Indexed: 12/26/2022] Open
Abstract
Background Cells adapt their metabolism and activities in response to signals from their surroundings, and this ability is essential for their survival in the face of perturbations. In tissues a deficit of these mechanisms is commonly associated with cellular aging and diseases, such as cardiovascular disease, cancer, immune system decline, and neurological pathologies. Several proteins have been identified as being able to respond directly to energy, nutrient, and growth factor levels and stress stimuli in order to mediate adaptations in the cell. In particular, mTOR, AMPK, and sirtuins are known to play an essential role in the management of metabolic stress and energy balance in mammals. Methods To understand the complex interactions of these signalling pathways and environmental signals, and how those interactions may impact lifespan and health-span, we have developed a computational model of metabolic signalling pathways. Specifically, the model includes (i) the insulin/IGF-1 pathway, which couples energy and nutrient abundance to the execution of cell growth and division, (ii) mTORC1 and the amino acid sensors such as sestrin, (iii) the Preiss-Handler and salvage pathways, which regulate the metabolism of NAD+ and the NAD+ -consuming factor SIRT1, (iv) the energy sensor AMPK, and (v) transcription factors FOXO and PGC-1α. Results The model simulates the interactions among key regulators such as AKT, mTORC1, AMPK, NAD+ , and SIRT, and predicts their dynamics. Key findings include the clinically important role of PRAS40 and diet in mTORC1 inhibition, and a potential link between SIRT1-activating compounds and premature autophagy. Moreover, the model captures the exquisite interactions of leucine, sestrin2, and arginine, and the resulting signal to the mTORC1 pathway. These results can be leveraged in the development of novel treatment of cancers and other diseases. Conclusions This study presents a state-of-the-art computational model for investigating the interactions among signaling pathways and environmental stimuli in growth, ageing, metabolism, and diseases. The model can be used as an essential component to simulate gene manipulation, therapies (e.g., rapamycin and wortmannin), calorie restrictions, and chronic stress, and assess their functional implications on longevity and ageing‐related diseases. Video Abstract
Supplementary Information The online version contains supplementary material available at 10.1186/s12964-021-00706-1.
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Affiliation(s)
- Mehrshad Sadria
- Department of Applied Mathematics, University of Waterloo, Waterloo, ON, Canada.
| | - Anita T Layton
- Department of Applied Mathematics, University of Waterloo, Waterloo, ON, Canada.,Department of Biology, Cheriton School of Computer Science, and School of Pharmacy, University of Waterloo, Waterloo, ON, Canada
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Lifelong Aerobic Exercise Alleviates Sarcopenia by Activating Autophagy and Inhibiting Protein Degradation via the AMPK/PGC-1α Signaling Pathway. Metabolites 2021; 11:metabo11050323. [PMID: 34069829 PMCID: PMC8157243 DOI: 10.3390/metabo11050323] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 05/12/2021] [Accepted: 05/14/2021] [Indexed: 12/11/2022] Open
Abstract
Sarcopenia is an aging-induced syndrome characterized by a progressive reduction of skeletal muscle mass and strength. Increasing evidence has attested that appropriate and scientific exercise could induce autophagy or optimize the functional status of autophagy, which plays a critical role in senescent muscular dystrophy. As a publicly recognized strategy for extending lifespan and improving the health of the elderly, the underlying mechanisms of lifelong regular aerobic exercise for the prevention of sarcopenia have not been fully elucidated. To explore the role of lifelong aerobic exercise in the beneficial regulation of autophagic signaling pathways in senescent skeletal muscle, the natural aging mice were used as the sarcopenia model and subjected to lifelong treadmill running to evaluate corresponding parameters related to skeletal muscle atrophy and autophagic signaling pathways. Compared with the young control mice, the aged mice showed a significant reduction in skeletal muscle mass, gastrocnemius muscle weight/body weight (GMW/BW) ratio, and cross-sectional areas (CSA) of skeletal muscle fibers (p < 0.01). In contrast, lifelong aerobic exercise effectively rescued these reduced biomarkers associated with muscle atrophy. Moreover, as shown in the activated AMPK/PGC-1α signaling pathway, lifelong aerobic exercise successfully prevented the aging-induced impairment of the ubiquitin-proteasome system (UPS), excessive apoptosis, defective autophagy, and mitochondrial dysfunction. The exercise-induced autophagy suppressed the key regulatory components of the UPS, inhibited excessive apoptosis, and optimized mitochondrial quality control, thereby preventing and delaying aging-induced skeletal muscle atrophy.
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Huang P, Bai L, Liu L, Fu J, Wu K, Liu H, Liu Y, Qi B, Qi B. Redd1 knockdown prevents doxorubicin-induced cardiac senescence. Aging (Albany NY) 2021; 13:13788-13806. [PMID: 33962393 PMCID: PMC8202877 DOI: 10.18632/aging.202972] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Accepted: 03/23/2021] [Indexed: 12/13/2022]
Abstract
Regulated in development and DNA damage response-1 (Redd1) is a stress-response gene that is transcriptionally induced by diverse stressful stimuli to influence cellular growth and survival. Although evidence suggests that aging may drive Redd1 expression in skeletal muscles, the expression patterns and functions of Redd1 in senescent cardiomyocytes remain unspecified. To address this issue, in vitro and in vivo models of cardiomyocyte senescence were established by administration of doxorubicin (Dox). Redd1 overexpression and knockdown was achieved in cultured H9c2 cardiomyocytes and mouse tissues using, respectively, lentivirals and adeno-associated virus 9 (AAV9) vectors. In the hearts of both aged (24 months old) and Dox-treated mice, as well as in Dox-exposed H9c2 cardiomyocytes, high Redd1 expression accompanied the increase in both cellular senescence markers (p16INK4a and p21) and pro-inflammatory cytokine expression indicative of a stress-associated secretory phenotype (SASP). Notably, Redd1 overexpression accentuated, whereas Redd1 silencing markedly attenuated, Dox-induced cardiomyocyte senescence features both in vitro and in vivo. Notably, AAV9-shRNA-mediated Redd1 silencing significantly alleviated Dox-induced cardiac dysfunction. Moreover, through pharmacological inhibition, immunofluorescence, and western blotting, signaling pathway analyses indicated that Redd1 promotes cardiomyocyte senescence as a downstream effector of p38 MAPK to promote NF-kB signaling via p65 phosphorylation and nuclear translocation.
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Affiliation(s)
- Pianpian Huang
- Department of Geriatrics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430022, China
- Department of Geriatrics, Wuhan No.1 Hospital, Wuhan, Hubei 430022, China
| | - Lijuan Bai
- Department of Geriatrics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430022, China
| | - Lihua Liu
- Department of Geriatrics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430022, China
| | - Jun Fu
- Department of Radiology, Wuhan No.1 Hospital, Wuhan, Hubei 430022, China
| | - Kefei Wu
- Department of Geriatrics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430022, China
| | - Hongxia Liu
- Department of Geriatrics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430022, China
| | - Yun Liu
- Department of Geriatrics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430022, China
| | - Benming Qi
- Department of Otorhinolaryngology, First People’s Hospital of Yunnan Province, Kunming, Yunnan 650000, China
| | - Benling Qi
- Department of Geriatrics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430022, China
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Lee EJ, Neppl RL. Influence of Age on Skeletal Muscle Hypertrophy and Atrophy Signaling: Established Paradigms and Unexpected Links. Genes (Basel) 2021; 12:genes12050688. [PMID: 34063658 PMCID: PMC8147613 DOI: 10.3390/genes12050688] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Revised: 04/26/2021] [Accepted: 04/27/2021] [Indexed: 12/16/2022] Open
Abstract
Skeletal muscle atrophy in an inevitable occurrence with advancing age, and a consequence of disease including cancer. Muscle atrophy in the elderly is managed by a regimen of resistance exercise and increased protein intake. Understanding the signaling that regulates muscle mass may identify potential therapeutic targets for the prevention and reversal of muscle atrophy in metabolic and neuromuscular diseases. This review covers the major anabolic and catabolic pathways that regulate skeletal muscle mass, with a focus on recent progress and potential new players.
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Dalle S, Van Roie E, Hiroux C, Vanmunster M, Coudyzer W, Suhr F, Bogaerts S, Van Thienen R, Koppo K. Omega-3 Supplementation Improves Isometric Strength But Not Muscle Anabolic and Catabolic Signaling in Response to Resistance Exercise in Healthy Older Adults. J Gerontol A Biol Sci Med Sci 2021; 76:406-414. [PMID: 33284965 PMCID: PMC7907485 DOI: 10.1093/gerona/glaa309] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Indexed: 12/11/2022] Open
Abstract
Old skeletal muscle exhibits decreased anabolic sensitivity, eventually contributing to muscle wasting. Besides anabolism, also muscle inflammation and catabolism are critical players in regulating the old skeletal muscle's sensitivity. Omega-3 fatty acids (ω-3) are an interesting candidate to reverse anabolic insensitivity via anabolic actions. Yet, it remains unknown whether ω-3 also attenuates muscle inflammation and catabolism. The present study investigates the effect of ω-3 supplementation on muscle inflammation and metabolism (anabolism/catabolism) upon resistance exercise (RE). Twenty-three older adults (65-84 years; 8♀) were randomized to receive ω-3 (~3 g/d) or corn oil (placebo [PLAC]) and engaged in a 12-week RE program (3×/wk). Before and after intervention, muscle volume, strength, and systemic inflammation were assessed, and muscle biopsies were analyzed for markers of anabolism, catabolism, and inflammation. Isometric knee-extensor strength increased in ω-3 (+12.2%), but not in PLAC (-1.4%; pinteraction = .015), whereas leg press strength improved in both conditions (+27.1%; ptime < .001). RE, but not ω-3, decreased inflammatory (p65NF-κB) and catabolic (FOXO1, LC3b) markers, and improved muscle quality. Yet, muscle volume remained unaffected by RE and ω-3. Accordingly, muscle anabolism (mTORC1) and plasma C-reactive protein remained unchanged by RE and ω-3, whereas serum IL-6 tended to decrease in ω-3 (pinteraction = .07). These results show that, despite no changes in muscle volume, RE-induced gains in isometric strength can be further enhanced by ω-3. However, ω-3 did not improve RE-induced beneficial catabolic or inflammatory adaptations. Irrespective of muscle volume, gains in strength (primary criterion for sarcopenia) might be explained by changes in muscle quality due to muscle inflammatory or catabolic signaling.
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Affiliation(s)
- Sebastiaan Dalle
- Exercise Physiology Research Group, Department of Movement Sciences, KU Leuven, Belgium
| | - Evelien Van Roie
- Physical Activity, Sports and Health Research Group, Department of Movement Sciences, KU Leuven, Belgium
| | - Charlotte Hiroux
- Exercise Physiology Research Group, Department of Movement Sciences, KU Leuven, Belgium
| | - Mathias Vanmunster
- Exercise Physiology Research Group, Department of Movement Sciences, KU Leuven, Belgium
| | - Walter Coudyzer
- Department of Morphology and Medical Imaging, Faculty of Medicine, Radiology Section, KU Leuven, Belgium
| | - Frank Suhr
- Exercise Physiology Research Group, Department of Movement Sciences, KU Leuven, Belgium
| | - Stijn Bogaerts
- Locomotor and Neurological Disorders, Department of Development and Regeneration, KU Leuven, Belgium
| | - Ruud Van Thienen
- Research Group for Neurorehabilitation, Department of Rehabilitation Sciences, KU Leuven, Belgium
| | - Katrien Koppo
- Exercise Physiology Research Group, Department of Movement Sciences, KU Leuven, Belgium
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The efficacy of essential amino acid supplementation for augmenting dietary protein intake in older adults: implications for skeletal muscle mass, strength and function. Proc Nutr Soc 2020; 80:230-242. [PMID: 33315000 DOI: 10.1017/s0029665120008010] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The primary aim of this review is to evaluate the efficacy of essential amino acid (EAA) supplementation as a strategy to increase dietary protein intake and improve muscle mass, strength and function in older adults. A sufficient daily protein intake is widely recognised to be fundamental for the successful management of sarcopenia in older undernourished adults. In practice, optimising protein intakes in older adults is complex, requiring consideration of the dose and amino acid composition (i.e. a complete EAA profile and abundant leucine content) of ingested protein on a per meal basis, alongside the age-related decline in appetite and the satiating properties of protein. Recent studies in older adults demonstrate that EAA-based supplements are non-satiating and can be administered alongside food to enhance the anabolic properties of a meal containing a suboptimal dose of protein; an effect magnified when combined with resistance exercise training. These findings support the notion that EAA supplementation could serve as an effective strategy to improve musculoskeletal health in older adults suffering from non-communicable diseases such as sarcopenia. Compliance is critical for the long-term success of complex interventions. Hence, aspects of palatability and desire to eat are important considerations regarding EAA supplementation. In conclusion, EAA-based supplements enriched with l-leucine offer an alternative strategy to whole protein sources to assist older adults in meeting protein recommendations. In practice, EAA supplements could be administered alongside meals of suboptimal protein content, or alternatively between meals on occasions when older adults achieve their per meal protein intake recommendations.
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Effects of high protein, low-glycemic index diet on lean body mass, strength, and physical performance in late postmenopausal women: a randomized controlled trial. ACTA ACUST UNITED AC 2020; 28:307-317. [PMID: 33201025 DOI: 10.1097/gme.0000000000001692] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
OBJECTIVE To investigate whether increasing protein consumption to twice the recommended daily allowance (RDA) by The Institute of Medicine affects lean body mass (LBM), muscle strength, and physical performance in late postmenopausal women. METHODS Parallel-group randomized trial with 26 apparently healthy women aged ≥ 65 years. Participants were randomly assigned to low-glycemic index diets with protein consumption at current RDA (0.8 g/kg body weight) or twice the RDA (2RDA, 1.6 g/kg body weight). Protein intake was assessed by 24-hours urinary nitrogen excretion. Change in LBM was measured by dual-energy X-ray absorptiometry at 3 and 6 months. Secondary outcomes were appendicular lean mass, handgrip strength by dynamometry, and physical performance by gait speed. RESULTS Mean age was 70.8 ± 3.6 years, and mean BMI was 26.1 ± 3.5 kg/m2 in the overall sample. The RDA and 2RDA groups did not differ regarding baseline dietary intake. Changes from baseline in LBM (0.07 kg; 95% CI, -0.39; 0.52 kg; P = 0.100) and appendicular lean mass (0.07 kg; 95% CI, -0.34; 0.47 kg; P = 0.100) did not differ between the groups. Total body fat (-1.41 kg; 95% CI, -2.62; 0.20 kg; P = 0.019) and trunk fat mass (-0.90 kg; 95% CI, -1.55; -0.24 kg; P = 0.005) decreased similarly in both groups at the end of intervention. Adjusting for baseline BMI did not alter these findings. Handgrip strength and 4-m gait speed increased after the intervention, with no significant difference between the groups. CONCLUSIONS Protein intake exceeding the RDA did not increase LBM, strength, and physical performance in a sample of late postmenopausal woman consuming a low-glycemic index diet for 6 months.
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Effects of acute and chronic strength training on skeletal muscle autophagy in frail elderly men and women. Exp Gerontol 2020; 142:111122. [PMID: 33132146 DOI: 10.1016/j.exger.2020.111122] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 10/09/2020] [Accepted: 10/14/2020] [Indexed: 12/19/2022]
Abstract
Aging is associated with alterations in skeletal muscle autophagy, potentially affecting both muscle mass and quality in a negative manner. Strength training with protein supplementation has been reported to improve both muscle mass and quality in frail elderly individuals, but whether improvements are accompanied by alterations in protein quality control is not known. To address this issue, we investigated protein degradation markers in skeletal muscle biopsies (m. vastus lateralis) from twenty-four frail elderly men and women (86 ± 7 yr) after acute and chronic (10 weeks) strength training with protein supplementation (ST + PRO) or protein supplementation alone (PRO). Acute increases in mRNA expression of genes related to the ubiquitin proteasome system (MuRF-1, MUSA1), autophagy (ATG7, LC3, p62), and mitochondrial fission (DRP1) were observed after the first, but not after the last training session in ST + PRO. Acute changes in gene expression were accompanied by changes in protein levels of both LC3-I and LC3-II. Hence, the acute training-induced activation of proteasomal degradation and autophagy seems to depend on training status, with activation in the untrained, but not trained state. The ten-week training intervention did not affect basal levels of autophagy mRNAs and proteins, and neither markers of the ubiquitin-proteasome system. This suggests that a relatively short period of strength training may not be sufficient to increase the basal rate of protein degradation in frail elderly.
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Liao CD, Wu YT, Tsauo JY, Chen PR, Tu YK, Chen HC, Liou TH. Effects of Protein Supplementation Combined with Exercise Training on Muscle Mass and Function in Older Adults with Lower-Extremity Osteoarthritis: A Systematic Review and Meta-Analysis of Randomized Trials. Nutrients 2020; 12:nu12082422. [PMID: 32806718 PMCID: PMC7468926 DOI: 10.3390/nu12082422] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 08/07/2020] [Accepted: 08/10/2020] [Indexed: 02/07/2023] Open
Abstract
Aging and osteoarthritis (OA) are associated with a high risk of muscle mass loss, which can lead to physical disability. This study investigated the effectiveness of protein supplementation combined with exercise training (PS + ET) in improving muscle mass and functional outcomes in older adults with lower-limb OA. A comprehensive search of online databases was performed to identify randomized controlled trials (RCTs) on the effectiveness of PS + ET in older adults with hip or knee OA. Meta-analysis and risk of bias assessment of the included RCTs were conducted. Six RCTs were included in this systemic review; they had a median (range/total) Physiotherapy Evidence Database (PEDro) score of 7 (6-9) out of 10, respectively. Five RCTs that enrolled patients who underwent total joint replacement were included in this meta-analysis. The PS + ET group exhibited significant improvements in muscle mass (standard mean difference [SMD] = 1.13, p < 0.00001), pain (SMD = 1.36, p < 0.00001), and muscle strength (SMD = 0.44, p = 0.04). Our findings suggest that PS + ET improves muscle mass, muscle strength, and functional outcomes and reduces pain in older adults with lower-limb OA, particularly in those who have undergone total joint replacement.
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Affiliation(s)
- Chun-De Liao
- School and Graduate Institute of Physical Therapy, College of Medicine, National Taiwan University, Taipei 100025, Taiwan; (C.-D.L.); (Y.-T.W.); (J.-Y.T.)
- Department of Physical Medicine and Rehabilitation, Shuang Ho Hospital, Taipei Medical University, New Taipei City 235041, Taiwan;
| | - Yen-Tzu Wu
- School and Graduate Institute of Physical Therapy, College of Medicine, National Taiwan University, Taipei 100025, Taiwan; (C.-D.L.); (Y.-T.W.); (J.-Y.T.)
- Physical Therapy Center, National Taiwan University Hospital, Taipei 100229, Taiwan
| | - Jau-Yih Tsauo
- School and Graduate Institute of Physical Therapy, College of Medicine, National Taiwan University, Taipei 100025, Taiwan; (C.-D.L.); (Y.-T.W.); (J.-Y.T.)
| | - Pey-Rong Chen
- Department of Dietetics, National Taiwan University Hospital, Taipei 100225, Taiwan;
- School of Nutrition and Health Sciences, Taipei Medical University, Taipei 110301, Taiwan
| | - Yu-Kang Tu
- Institute of Epidemiology and Preventive Medicine, College of Public Health, National Taiwan University, Taipei 100025, Taiwan;
| | - Hung-Chou Chen
- Department of Physical Medicine and Rehabilitation, Shuang Ho Hospital, Taipei Medical University, New Taipei City 235041, Taiwan;
- Department of Physical Medicine and Rehabilitation, School of Medicine, College of Medicine, Taipei Medical University, Taipei 110301, Taiwan
| | - Tsan-Hon Liou
- Department of Physical Medicine and Rehabilitation, Shuang Ho Hospital, Taipei Medical University, New Taipei City 235041, Taiwan;
- Department of Physical Medicine and Rehabilitation, School of Medicine, College of Medicine, Taipei Medical University, Taipei 110301, Taiwan
- Correspondence: ; Tel.: +886-2-2249-0088 (ext. 1600); Fax: +886-2-2248-0577
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Scheuren AC, D'Hulst G, Kuhn GA, Masschelein E, Wehrle E, De Bock K, Müller R. Hallmarks of frailty and osteosarcopenia in prematurely aged PolgA (D257A/D257A) mice. J Cachexia Sarcopenia Muscle 2020; 11:1121-1140. [PMID: 32596975 PMCID: PMC7432580 DOI: 10.1002/jcsm.12588] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Revised: 02/14/2020] [Accepted: 02/24/2020] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Frailty is a geriatric syndrome characterized by increased susceptibility to adverse health outcomes. One major determinant thereof is the gradual weakening of the musculoskeletal system and the associated osteosarcopenia. To improve our understanding of the underlying pathophysiology and, more importantly, to test potential interventions aimed at counteracting frailty, suitable animal models are needed. METHODS To evaluate the relevance of prematurely aged PolgA(D257A/D257A) mice as a model for frailty and osteosarcopenia, we quantified the clinical mouse frailty index in PolgA(D257A/D257A) and wild-type littermates (PolgA(+/+) , WT) with age and concertedly assessed the quantity and quality of bone and muscle tissue. Lastly, the anabolic responsiveness of skeletal muscle, muscle progenitors, and bone was assessed. RESULTS PolgA(D257A/D257A) accumulated health deficits at a higher rate compared with WT, resulting in a higher frailty index at 40 and 46 weeks of age (+166%, +278%, P < 0.0001), respectively, with no differences between genotypes at 34 weeks. Concomitantly, PolgA(D257A/D257A) displayed progressive musculoskeletal deterioration such as reduced bone and muscle mass as well as impaired functionality thereof. In addition to lower muscle weights (-14%, P < 0.05, -23%, P < 0.0001) and fibre area (-20%, P < 0.05, -22%, P < 0.0001) at 40 and 46 weeks, respectively, PolgA(D257A/D257A) showed impairments in grip strength and concentric muscle forces (P < 0.05). PolgA(D257A/D257A) mutation altered the acute response to various anabolic stimuli in skeletal muscle and muscle progenitors. While PolgA(D257A/D257A) muscles were hypersensitive to eccentric contractions as well as leucine administration, shown by larger downstream signalling response of the mechanistic target of rapamycin complex 1, myogenic progenitors cultured in vitro showed severe anabolic resistance to leucine and robust impairments in cell proliferation. Longitudinal micro-computed tomography analysis of the sixth caudal vertebrae showed that PolgA(D257A/D257A) had lower bone morphometric parameters (e.g. bone volume fraction, trabecular, and cortical thickness, P < 0.05) as well as reduced remodelling activities (e.g. bone formation and resorption rate, P < 0.05) compared with WT. When subjected to 4 weeks of cyclic loading, young but not aged PolgA(D257A/D257A) caudal vertebrae showed load-induced bone adaptation, suggesting reduced mechanosensitivity with age. CONCLUSIONS PolgA(D257A/D257A) mutation leads to hallmarks of age-related frailty and osteosarcopenia and provides a powerful model to better understand the relationship between frailty and the aging musculoskeletal system.
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Affiliation(s)
| | - Gommaar D'Hulst
- Laboratory of Exercise and HealthETH ZurichZurichSwitzerland
| | | | - Evi Masschelein
- Laboratory of Exercise and HealthETH ZurichZurichSwitzerland
| | - Esther Wehrle
- Institute for BiomechanicsETH ZurichZurichSwitzerland
| | - Katrien De Bock
- Laboratory of Exercise and HealthETH ZurichZurichSwitzerland
| | - Ralph Müller
- Institute for BiomechanicsETH ZurichZurichSwitzerland
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25
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Endo Y, Nourmahnad A, Sinha I. Optimizing Skeletal Muscle Anabolic Response to Resistance Training in Aging. Front Physiol 2020; 11:874. [PMID: 32792984 PMCID: PMC7390896 DOI: 10.3389/fphys.2020.00874] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Accepted: 06/29/2020] [Indexed: 12/13/2022] Open
Abstract
Loss of muscle mass and strength with aging, also termed sarcopenia, results in a loss of mobility and independence. Exercise, particularly resistance training, has proven to be beneficial in counteracting the aging-associated loss of skeletal muscle mass and function. However, the anabolic response to exercise in old age is not as robust, with blunted improvements in muscle size, strength, and function in comparison to younger individuals. This review provides an overview of several physiological changes which may contribute to age-related loss of muscle mass and decreased anabolism in response to resistance training in the elderly. Additionally, the following supplemental therapies with potential to synergize with resistance training to increase muscle mass are discussed: nutrition, creatine, anti-inflammatory drugs, testosterone, and growth hormone (GH). Although these interventions hold some promise, further research is necessary to optimize the response to exercise in elderly patients.
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Affiliation(s)
- Yori Endo
- Division of Plastic Surgery, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States
| | - Atousa Nourmahnad
- Division of Plastic Surgery, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States
| | - Indranil Sinha
- Division of Plastic Surgery, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States.,Harvard Department of Stem Cell and Regenerative Biology, Harvard Stem Cell Institute, Cambridge, MA, United States
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26
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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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Smith HJ, Sharma A, Mair WB. Metabolic Communication and Healthy Aging: Where Should We Focus Our Energy? Dev Cell 2020; 54:196-211. [PMID: 32619405 DOI: 10.1016/j.devcel.2020.06.011] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Revised: 06/01/2020] [Accepted: 06/07/2020] [Indexed: 02/09/2023]
Abstract
Aging is associated with a loss of metabolic homeostasis and plasticity, which is causally linked to multiple age-onset pathologies. The majority of the interventions-genetic, dietary, and pharmacological-that have been found to slow aging and protect against age-related disease in various organisms do so by targeting central metabolic pathways. However, targeting metabolic pathways chronically and ubiquitously makes it difficult to define the downstream effects responsible for lifespan extension and often results in negative effects on growth and health, limiting therapeutic potential. Insight into how metabolic signals are relayed between tissues, cells, and organelles opens up new avenues to target metabolic regulators locally rather than globally for healthy aging. In this review, we discuss the pro-longevity effects of targeting metabolic pathways in specific tissues and how these interventions communicate with distal cells to modulate aging. These studies may be crucial in designing interventions that promote longevity without negative health consequences.
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Affiliation(s)
- Hannah J Smith
- Harvard T.H. Chan School of Public Health, Department of Molecular Metabolism, Boston, MA, USA
| | - Arpit Sharma
- Harvard T.H. Chan School of Public Health, Department of Molecular Metabolism, Boston, MA, USA
| | - William B Mair
- Harvard T.H. Chan School of Public Health, Department of Molecular Metabolism, Boston, MA, USA.
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28
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Age-dependent effects of caloric restriction on mTOR and ubiquitin-proteasome pathways in skeletal muscles. GeroScience 2019; 41:871-880. [PMID: 31676964 DOI: 10.1007/s11357-019-00109-8] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Accepted: 09/20/2019] [Indexed: 01/12/2023] Open
Abstract
In skeletal muscles, calorie restriction (CR) preserves muscle mass in middle-aged rats but not younger rats. The underlying mechanisms for this age-specific response are unknown. Skeletal muscle mass depends on several factors, with protein synthesis and degradation playing major roles. Therefore, the purpose of this study was to investigate whether CR affects younger and older animals differently on mTOR signaling and ubiquitin-proteasome pathway (UPP). Four-, 8-, and 16-month-old rats, with or without 40% CR for a duration of 14 weeks, were sacrificed after an overnight fasting. Total protein content and the phosphorylation level of AKT, mTOR, S6K, and 4EBP1 and protein content of key markers in the UPP (FOXO3a, atrogin, MuRF1, ubiquitinated proteins, proteasome subunits alpha 7 and beta 5) were determined. Unlike younger rats, CR decreased the content of phosphorylated mTOR, S6K, phosphorylated S6K, FOXO3a, and ubiquitinated proteins in middle-aged rats. In conclusion, CR-induced reduction of content/ phosphorylation levels of key proteins in mTOR signaling and the UPP occurred in the middle-aged rats but not younger rats. The age-dependent effects of CR on mTOR signaling and the UPP indirectly explained the age-related effects of CR on muscle mass of animals.
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29
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Barclay RD, Burd NA, Tyler C, Tillin NA, Mackenzie RW. The Role of the IGF-1 Signaling Cascade in Muscle Protein Synthesis and Anabolic Resistance in Aging Skeletal Muscle. Front Nutr 2019; 6:146. [PMID: 31552262 PMCID: PMC6746962 DOI: 10.3389/fnut.2019.00146] [Citation(s) in RCA: 78] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Accepted: 08/23/2019] [Indexed: 12/14/2022] Open
Abstract
Sarcopenia is defined as the combined loss of skeletal muscle strength, function, and/or mass with aging. This degenerative loss of muscle mass is associated with poor quality of life and early mortality humans. The loss of muscle mass occurs due to acute changes in daily muscle net protein balance (NPB). It is generally believed a poor NPB occurs due to reduced muscle protein synthetic responses to exercise, dietary amino acid availability, or an insensitivity of insulin to suppress breakdown. Hence, aging muscles appear to be resistant to the anabolic action of exercise and protein (amino acids or hormonal) when compared to their younger counterparts. The mechanisms that underpin anabolic resistance to anabolic stimuli (protein and resistance exercise) are multifactorial and may be partly driven by poor lifestyle choices (increased sedentary time and reduced dietary protein intake) as well as an inherent dysregulated mechanism in old muscles irrespective of the environmental stimuli. The insulin like growth factor 1 (IGF-1), Akt /Protein Kinase B and mechanistic target of rapamycin (mTOR) pathway is the primary driver between mechanical contraction and protein synthesis and may be a site of dysregulation between old and younger people. Therefore, our review aims to describe and summarize the differences seen in older muscle in this pathway in response to resistance exercise (RE) and describe approaches that researchers have sought out to maximize the response in muscle. Furthermore, this review will present the hypothesis that inositol hexakisphosphate kinase 1 (IP6K1) may be implicated in IGF-1 signaling and thus sarcopenia, based on recent evidence that IGF-1 and insulin share some intracellular bound signaling events and that IP6K1 has been implicated in skeletal muscle insulin resistance.
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Affiliation(s)
- Richie D Barclay
- Department of Life Sciences, University of Roehampton, London, United Kingdom
| | - Nicholas A Burd
- Division of Nutritional Sciences, Department of Kinesiology and Community Health, University of Illinois, Urbana, IL, United States
| | - Christopher Tyler
- Department of Life Sciences, University of Roehampton, London, United Kingdom
| | - Neale A Tillin
- Department of Life Sciences, University of Roehampton, London, United Kingdom
| | - Richard W Mackenzie
- Department of Life Sciences, University of Roehampton, London, United Kingdom
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30
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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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31
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Graber TG, Fandrey KR, Thompson LV. Novel individualized power training protocol preserves physical function in adult and older mice. GeroScience 2019; 41:165-183. [PMID: 31076998 PMCID: PMC6544743 DOI: 10.1007/s11357-019-00069-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Accepted: 04/16/2019] [Indexed: 11/27/2022] Open
Abstract
Sarcopenia, the age-related loss of muscle mass and strength, contributes to frailty, functional decline, and reduced quality of life in older adults. Exercise is a recognized therapy for sarcopenia and muscle dysfunction, though not a cure. Muscle power declines at an increased rate compared to force, and force output declines earlier than mass. Thus, there is a need for research of exercise focusing on improving power output and functionality in older adults. Our primary purpose was proof-of-concept that a novel individualized power exercise modality would induce positive adaptations in adult mice, before the exercise program was applied to an aged cohort. We hypothesized that after following our protocol, both adult and older mice would show improved function, though there would be evidence of anabolic resistance in the older mice. Male C57BL/6 mice (12 months of age at study conclusion) were randomized into control (n = 9) and exercise (n = 6) groups. The trained group used progressive resistance (with a weighted harness) and intensity (~ 4-10 rpm) on a custom motorized running wheel. The mice trained similarly to a human workout regimen (4-5 sets/session, 3 sessions/week, for 12 weeks). We determined significant (p < 0.05) positive adaptations post-intervention, including: neuromuscular function (rotarod), strength/endurance (inverted cling grip test), training physiology (force/power output per session), muscle size (soleus mass), and power/velocity of contraction (in vitro physiology). Secondly, we trained a cohort of older male mice (28 months old at conclusion): control (n = 12) and exercised (n = 8). While the older exercised mice did preserve function and gain benefits, they also demonstrated evidence of anabolic resistance.
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Affiliation(s)
- Ted G. Graber
- Department of Nutrition and Metabolism, Division of Rehabilitation Science, University of Texas Medical Branch, Galveston, TX USA
| | - Katie R. Fandrey
- Program in Physical Therapy, University of Minnesota-Twin Cities, Minneapolis, MN USA
| | - LaDora V. Thompson
- Department of Physical Therapy & Athletic Training, Boston University, Boston, MA USA
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32
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Ross M, Lithgow H, Hayes L, Florida-James G. Potential Cellular and Biochemical Mechanisms of Exercise and Physical Activity on the Ageing Process. Subcell Biochem 2019; 91:311-338. [PMID: 30888658 DOI: 10.1007/978-981-13-3681-2_12] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Exercise in young adults has been consistently shown to improve various aspects of physiological and psychological health but we are now realising the potential benefits of exercise with advancing age. Specifically, exercise improves cardiovascular, musculoskeletal, and metabolic health through reductions in oxidative stress, chronic low-grade inflammation and modulating cellular processes within a variety of tissues. In this this chapter we will discuss the effects of acute and chronic exercise on these processes and conditions in an ageing population, and how physical activity affects our vasculature, skeletal muscle function, our immune system, and cardiometabolic risk in older adults.
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Affiliation(s)
- Mark Ross
- School of Applied Science, Edinburgh Napier University, Edinburgh, Scotland, UK.
| | - Hannah Lithgow
- School of Applied Science, Edinburgh Napier University, Edinburgh, Scotland, UK
| | - Lawrence Hayes
- Active Ageing Research Group, University of Cumbria, Lancaster, UK
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33
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Liao CD, Lee PH, Hsiao DJ, Huang SW, Tsauo JY, Chen HC, Liou TH. Effects of Protein Supplementation Combined with Exercise Intervention on Frailty Indices, Body Composition, and Physical Function in Frail Older Adults. Nutrients 2018; 10:E1916. [PMID: 30518122 PMCID: PMC6315527 DOI: 10.3390/nu10121916] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Revised: 11/28/2018] [Accepted: 11/30/2018] [Indexed: 12/30/2022] Open
Abstract
Aging poses a high risk of lean mass loss, which can be effectively improved through resistance exercise training (RET), or multicomponent exercise training (MET) as well as nutrition supplementation, such as protein supplementation (PS). This study investigated the effects of PS plus exercise training on frail older individuals. A comprehensive search of online databases was performed to identify randomized controlled trials (RCTs) that reported the efficacy of PS combined with RET or MET in frail older individuals. The included RCTs were analyzed through a meta-analysis and risk-of-bias assessment. We finally included 22 RCTs in the meta-analysis, with a mean (range/total) Physiotherapy Evidence Database score of 6.7 (4⁻9/10). PS plus exercise training significantly improved the frailty status (odds ratio = 2.77; p = 0.006), lean mass (standard mean difference (SMD) = 0.52; p < 0.00001), leg strength (SMD = 0.37; p < 0.00001), and walking speed (SMD = 0.32; p = 0.002). Subgroup analyses revealed that PS plus MET exert significant effects on frailty indices, whereas PS plus RET further improves lean mass. Our findings suggest that PS plus RET as well as MET is effective in improving frailty status, lean mass, muscle strength, and physical mobility in frail older individuals.
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Affiliation(s)
- Chun-De Liao
- School and Graduate Institute of Physical Therapy, College of Medicine, National Taiwan University, Taipei 10055, Taiwan.
- Department of Physical Medicine and Rehabilitation, Shuang Ho Hospital, Taipei Medical University, Taipei 23561, Taiwan.
| | - Pi-Hsia Lee
- School of Nursing, College of Nursing, Taipei Medical University, Taipei 10675, Taiwan.
| | - Dun-Jen Hsiao
- School and Graduate Institute of Nutrition Science, College of Medicine, Taipei Medical University, Taipei 23561, Taiwan.
| | - Shih-Wei Huang
- Department of Physical Medicine and Rehabilitation, Shuang Ho Hospital, Taipei Medical University, Taipei 23561, Taiwan.
- Graduate Institute of Sports Science, National Taiwan Sport University, Taoyuan 33371, Taiwan.
| | - Jau-Yih Tsauo
- School and Graduate Institute of Physical Therapy, College of Medicine, National Taiwan University, Taipei 10055, Taiwan.
| | - Hung-Chou Chen
- Department of Physical Medicine and Rehabilitation, Shuang Ho Hospital, Taipei Medical University, Taipei 23561, Taiwan.
- Center for Evidence-Based Health Care, Shuang Ho Hospital, Taipei Medical University, Taipei 23561, Taiwan.
- Department of Physical Medicine and Rehabilitation, School of Medicine, College of Medicine, Taipei Medical University, Taipei 23561, Taiwan.
| | - Tsan-Hon Liou
- Department of Physical Medicine and Rehabilitation, Shuang Ho Hospital, Taipei Medical University, Taipei 23561, Taiwan.
- Department of Physical Medicine and Rehabilitation, School of Medicine, College of Medicine, Taipei Medical University, Taipei 23561, Taiwan.
- Obesity Research Center, Wan Fang Hospital, Taipei Medical University, Taipei 23561, Taiwan.
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Shimkus KL, Jefferson LS, Gordon BS, Kimball SR. Repressors of mTORC1 act to blunt the anabolic response to feeding in the soleus muscle of a cast-immobilized mouse hindlimb. Physiol Rep 2018; 6:e13891. [PMID: 30338657 PMCID: PMC6194210 DOI: 10.14814/phy2.13891] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Revised: 09/21/2018] [Accepted: 09/24/2018] [Indexed: 12/11/2022] Open
Abstract
We recently reported results showing that cast immobilization of a rat hindlimb rapidly leads to development of anabolic resistance as demonstrated by failure of oral leucine administration to activate the mechanistic target of rapamycin complex 1 (mTORC1) and stimulate protein synthesis in the soleus muscle. The goal of this study was to assess the possible contribution of several mTORC1 regulatory proteins to the development of anabolic resistance. To accomplish this, 14-week-old male C57BL/6 mice (n = 21) were subjected to unilateral cast immobilization of the hindlimb for either 1 or 3 days, and the immobilized limb was compared to its contralateral control. The mass of the soleus muscle was decreased in the immobilized compared to the non-immobilized limb within 72-h in association with diminished protein synthesis. In agreement with our previous report, a 24-h casting period was sufficient to induce anabolic resistance, as demonstrated by blunted re-feeding-induced activation of mTORC1. Moreover, resistance of mTORC1 activation was associated not only with upregulated expression of REDD1, but also with altered expression of other mTORC1 regulatory proteins, that is, Sestrin1 and DEP domain-containing mTOR interacting protein (DEPTOR). In addition, re-feeding-induced phosphorylation of DEPTOR was significantly impaired in the immobilized compared to the non-immobilized limb. This work builds upon previous discoveries by our laboratory to elucidate the blunted mTORC1 response to stimuli during disuse of skeletal muscle induced by cast immobilization while highlighting new potential therapeutic targets for future countermeasures against muscle atrophy.
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Affiliation(s)
- Kevin L. Shimkus
- Department of Cellular and Molecular PhysiologyThe Pennsylvania State University College of MedicineHersheyPennsylvania
| | - Leonard S. Jefferson
- Department of Cellular and Molecular PhysiologyThe Pennsylvania State University College of MedicineHersheyPennsylvania
| | | | - Scot R. Kimball
- Department of Cellular and Molecular PhysiologyThe Pennsylvania State University College of MedicineHersheyPennsylvania
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McCormick R, Vasilaki A. Age-related changes in skeletal muscle: changes to life-style as a therapy. Biogerontology 2018; 19:519-536. [PMID: 30259289 PMCID: PMC6223729 DOI: 10.1007/s10522-018-9775-3] [Citation(s) in RCA: 113] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Accepted: 09/19/2018] [Indexed: 12/13/2022]
Abstract
As we age, there is an age-related loss in skeletal muscle mass and strength, known as sarcopenia. Sarcopenia results in a decrease in mobility and independence, as well as an increase in the risk of other morbidities and mortality. Sarcopenia is therefore a major socio-economical problem. The mechanisms behind sarcopenia are unclear and it is likely that it is a multifactorial condition with changes in numerous important mechanisms all contributing to the structural and functional deterioration. Here, we review the major proposed changes which occur in skeletal muscle during ageing and highlight evidence for changes in physical activity and nutrition as therapeutic approaches to combat age-related skeletal muscle wasting.
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Affiliation(s)
- Rachel McCormick
- Musculoskeletal Biology II, Institute of Ageing and Chronic Disease, Centre for Integrated Research into Musculoskeletal Ageing, University of Liverpool, William Duncan Building, 6 West Derby Street, Liverpool, L7 8TX, UK.
| | - Aphrodite Vasilaki
- Musculoskeletal Biology II, Institute of Ageing and Chronic Disease, Centre for Integrated Research into Musculoskeletal Ageing, University of Liverpool, William Duncan Building, 6 West Derby Street, Liverpool, L7 8TX, UK
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Zeng N, D'Souza RF, Mitchell CJ, Cameron-Smith D. Sestrins are differentially expressed with age in the skeletal muscle of men: A cross-sectional analysis. Exp Gerontol 2018; 110:23-34. [DOI: 10.1016/j.exger.2018.05.006] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Revised: 03/21/2018] [Accepted: 05/07/2018] [Indexed: 12/15/2022]
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Skeletal muscle mass is associated with higher dietary protein intake and lower body fat in postmenopausal women: a cross-sectional study. Menopause 2018; 24:502-509. [PMID: 27922938 DOI: 10.1097/gme.0000000000000793] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
OBJECTIVE We investigated the association between skeletal muscle mass and dietary protein intake, habitual physical activity, body composition, and metabolic variables. METHODS One hundred three healthy postmenopausal women from southern Brazil (age 55.2 ± 4.9 y, body mass index 27.2 ± 4.6 kg/m) were enrolled. Bone mineral density, %body fat, %trunk fat mass, and appendicular lean mass were assessed by dual-energy x-ray absorptiometry, resting metabolic rate by indirect calorimetry, and habitual physical activity by pedometer. Skeletal muscle mass index (SMI) was expressed as appendicular lean mass standardized to body mass index. The cutoff for low lean mass was <0.512. Protein intake was measured by a validated food frequency questionnaire and categorized into tertiles: ≤0.93 g/kg body weight (BW), 0.94 to 1.29 g/kg BW, and ≥1.3 g protein/kg BW. RESULTS The prevalence of low lean mass (SMI <0.512) was 7%. Waist circumference, %body fat, trunk fat mass, and diastolic blood pressure were higher, whereas SMI and mean daily steps were lower in women with protein intake ≤0.93 g/kg BW. SMI was positively correlated with physical activity (r = 0.205, P = 0.038) and protein intake (r = 0.334, P = 0.001), and negatively correlated with waist circumference (r = -0.505, P < 0.001) and %body fat (r = 0.808, P < 0.001). Linear regression analysis adjusted for age, time since menopause, previous smoking behavior, and energy intake showed an independent, positive contribution of protein intake (mean difference 0.007, 95% CI, 0.001-0.014, P = 0.044) and an independent, negative contribution of %body fat (mean difference -0.010, 95%CI, -0.011 to -0.008, P < 0.001) to SMI. CONCLUSIONS In our healthy postmenopausal women, SMI was positively associated with protein intake and negatively associated with %body fat.
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Ogasawara R, Arihara Y, Takegaki J, Nakazato K, Ishii N. Relationship between exercise volume and muscle protein synthesis in a rat model of resistance exercise. J Appl Physiol (1985) 2017; 123:710-716. [DOI: 10.1152/japplphysiol.01009.2016] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Revised: 07/17/2017] [Accepted: 07/17/2017] [Indexed: 01/17/2023] Open
Abstract
Resistance exercise (RE) volume is recognized as an important factor that stimulates muscle protein synthesis (MPS) and is considered, at least in part, to be involved in the mammalian target of rapamycin complex 1 (mTORC1)-associated signaling. However, the effects of relatively high-volume RE on mTORC1 and MPS remain unclear. In the present study, we used an animal model of RE to investigate the relationship between RE volume and MPS. Male Sprague-Dawley rats were subjected to RE, and muscle samples were obtained 6 h after performing 1, 3, 5, 10, or 20 sets of RE. Although 1 set of RE did not increase MPS [measured by the surface sensing of translation (SUnSET) method], multiple sets (3, 5, 10, and 20 sets) significantly increased MPS. However, the increase in MPS reached a plateau after 3 or 5 sets of RE, and no further increase in MPS was observed with additional RE sets. In contrast to the MPS response, we observed that p70S6K phosphorylation at Thr389, a marker of mTORC1 activity, and Ser240/244 phosphorylation of rpS6, a downstream target of p70S6K, gradually increased with higher RE volume. The above results suggest that the relationship between RE volume and MPS was not linear. Thus the increase in MPS with increasing RE volume saturates before p70S6K phosphorylation, suggesting a threshold effect for the relationship between p70S6K activation and MPS. NEW & NOTEWORTHY The aim of this study was to investigate the relationship between resistance exercise (RE) volume and muscle protein synthesis. We found that the relationship between RE volume and p70S6K phosphorylation was almost linear, but the increase in muscle protein synthesis began to plateau after approximately five sets of RE.
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Affiliation(s)
- Riki Ogasawara
- Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Nagoya, Japan
- Department of Life Sciences, The University of Tokyo, Tokyo, Japan; and
| | - Yuki Arihara
- Department of Life Sciences, The University of Tokyo, Tokyo, Japan; and
| | - Junya Takegaki
- Department of Life Sciences, The University of Tokyo, Tokyo, Japan; and
| | - Koichi Nakazato
- Department of Exercise Physiology, Nippon Sport Science University, Tokyo, Japan
| | - Naokata Ishii
- Department of Life Sciences, The University of Tokyo, Tokyo, Japan; and
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Phillips BE, Williams JP, Greenhaff PL, Smith K, Atherton PJ. Physiological adaptations to resistance exercise as a function of age. JCI Insight 2017; 2:95581. [PMID: 28878131 PMCID: PMC5621901 DOI: 10.1172/jci.insight.95581] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Accepted: 08/03/2017] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND The impact of resistance exercise training (RE-T) across the life span is poorly defined. METHODS To resolve this, we recruited three distinct age cohorts of young (18-28 years; n = 11), middle-aged (45-55 years; n = 20), and older (nonsarcopenic; 65-75 years; n = 17) individuals to a cross-sectional intervention study. All subjects participated in 20 weeks of fully supervised whole-body progressive RE-T, undergoing assessment of body composition, muscle and vascular function, and metabolic health biomarkers before and after RE-T. Individuals also received stable isotope tracer infusions to ascertain muscle protein synthesis (MPS). RESULTS There was an age-related increase in adiposity, but only young and middle-age groups demonstrated reductions following RE-T. Increases in blood pressure with age were attenuated by RE-T in middle-aged, but not older, individuals, while age-related increases in leg vascular conductance were unaffected by RE-T. The index of insulin sensitivity was reduced by RE-T in older age. Despite being matched at baseline, only younger individuals increased muscle mass in response to RE-T, and there existed a negative correlation between age and muscle growth; in contrast, increases in mechanical quality were preserved across ages. Acute increases in MPS (upon feeding plus acute RE-T) were enhanced only in younger individuals, perhaps explaining greater hypertrophy. CONCLUSION Our data indicate that RE-T offsets some, but not all, negative characteristics of ageing - some of which are apparent in midlife. FUNDING Biotechnology and Biological Sciences Research Council (BB/C516779/1).
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Affiliation(s)
| | | | - Paul L. Greenhaff
- School of Life Sciences, Medical Research Council Arthritis Research UK Centre for Musculoskeletal Ageing Research, University of Nottingham, Nottingham and Derby, United Kingdom
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Halling JF, Pilegaard H. Autophagy-Dependent Beneficial Effects of Exercise. Cold Spring Harb Perspect Med 2017; 7:cshperspect.a029777. [PMID: 28270532 DOI: 10.1101/cshperspect.a029777] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Exercise has long been recognized as a powerful physiological stimulus for a wide variety of metabolic adaptations with implications for health and performance. The metabolic effects of exercise occur during and after each exercise bout and manifest as cumulative adaptive responses to successive exercise bouts. Studies on the beneficial effects of exercise have traditionally focused on the biosynthesis of metabolic proteins and organelles. However, the recycling of cellular components by autophagy has recently emerged as an important process involved in the adaptive responses to exercise. This review covers the regulation of autophagy by exercise, with emphasis on the potential autophagy-dependent beneficial effects of exercise.
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Affiliation(s)
- Jens Frey Halling
- Department of Biology, University of Copenhagen, 2100 Copenhagen, Denmark
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Wilson D, Jackson T, Sapey E, Lord JM. Frailty and sarcopenia: The potential role of an aged immune system. Ageing Res Rev 2017; 36:1-10. [PMID: 28223244 DOI: 10.1016/j.arr.2017.01.006] [Citation(s) in RCA: 319] [Impact Index Per Article: 45.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Revised: 01/26/2017] [Accepted: 01/31/2017] [Indexed: 12/19/2022]
Abstract
Frailty is a common negative consequence of ageing. Sarcopenia, the syndrome of loss of muscle mass, quality and strength, is more common in older adults and has been considered a precursor syndrome or the physical manifestation of frailty. The pathophysiology of both syndromes is incompletely described with multiple causes, inter-relationships and complex pathways proposed. Age-associated changes to the immune system (both immunesenescence, the decline in immune function with ageing, and inflammageing, a state of chronic inflammation) have been suggested as contributors to sarcopenia and frailty but a direct causative role remains to be established. Frailty, sarcopenia and immunesenescence are commonly described in older adults but are not ubiquitous to ageing. There is evidence that all three conditions are reversible and all three appear to share common inflammatory drivers. It is unclear whether frailty, sarcopenia and immunesenescence are separate entities that co-occur due to coincidental or potentially confounding factors, or whether they are more intimately linked by the same underlying cellular mechanisms. This review explores these possibilities focusing on innate immunity, and in particular associations with neutrophil dysfunction, inflammation and known mechanisms described to date. Furthermore, we consider whether the age-related decline in immune cell function (such as neutrophil migration), increased inflammation and the dysregulation of the phosphoinositide 3-kinase (PI3K)-Akt pathway in neutrophils could contribute pathogenically to sarcopenia and frailty.
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Lipina C, Hundal HS. Is REDD1 a Metabolic Éminence Grise? Trends Endocrinol Metab 2016; 27:868-880. [PMID: 27613400 PMCID: PMC5119498 DOI: 10.1016/j.tem.2016.08.005] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Revised: 08/04/2016] [Accepted: 08/09/2016] [Indexed: 01/31/2023]
Abstract
Regulated in development and DNA damage response 1 (REDD1) has been functionally linked to the control of diverse cellular processes due, at least in part, to its ability to repress mammalian or mechanistic Target of Rapamycin (mTOR) Complex-1 (mTORC1), a key protein complex controlled by hormonal and nutrient cues. Notably, emerging evidence suggests that REDD1 also regulates several pathways involved in modulating energy balance and metabolism. Herein, we discuss evidence implicating REDD1 as a key modulator of insulin action and metabolic function, including its potential contribution to mitochondrial biology and pancreatic islet function. Collectively, the available evidence suggests that REDD1 has a more prominent role in energy homeostasis than was previously thought, and implicates REDD1 as a potential therapeutic target for treatment of metabolic disorders.
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Affiliation(s)
- Christopher Lipina
- Division of Cell Signalling and Immunology, Sir James Black Centre, School of Life Sciences, University of Dundee, Dundee, DD1 5EH, UK
| | - Harinder S Hundal
- Division of Cell Signalling and Immunology, Sir James Black Centre, School of Life Sciences, University of Dundee, Dundee, DD1 5EH, UK.
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Lancha AH, Zanella R, Tanabe SGO, Andriamihaja M, Blachier F. Dietary protein supplementation in the elderly for limiting muscle mass loss. Amino Acids 2016; 49:33-47. [PMID: 27807658 DOI: 10.1007/s00726-016-2355-4] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Accepted: 10/18/2016] [Indexed: 12/14/2022]
Abstract
Supplementation with whey and other dietary protein, mainly associated with exercise training, has been proposed to be beneficial for the elderly to gain and maintain lean body mass and improve health parameters. The main objective of this review is to examine the evidence provided by the scientific literature indicating benefit from such supplementation and to define the likely best strategy of protein uptake for optimal objectified results in the elderly. Overall, it appears that an intake of approximately 0.4 g protein/kg BW per meal thus representing 1.2-1.6 g protein/kg BW/day may be recommended taking into account potential anabolic resistance. The losses of the skeletal muscle mass contribute to lower the capacity to perform activities in daily living, emphasizing that an optimal protein consumption may represent an important parameter to preserve independence and contribute to health status. However, it is worth noting that the maximal intake of protein with no adverse effect is not known, and that high levels of protein intake is associated with increased transfer of protein to the colon with potential deleterious effects. Thus, it is important to examine in each individual case the benefit that can be expected from supplementation with whey protein, taking into account the usual protein dietary intake.
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Affiliation(s)
- Antonio Herbert Lancha
- Laboratório de Nutrição e Metabolismo, Escola de Educação Física e Esporte da Universidade de São Paulo, EEFE-USP, R. Prof. Mello Moraes, 65, São Paulo, SP, CEP 05508-030, Brazil.
| | - Rudyard Zanella
- Laboratório de Nutrição e Metabolismo, Escola de Educação Física e Esporte da Universidade de São Paulo, EEFE-USP, R. Prof. Mello Moraes, 65, São Paulo, SP, CEP 05508-030, Brazil
| | - Stefan Gleissner Ohara Tanabe
- Laboratório de Nutrição e Metabolismo, Escola de Educação Física e Esporte da Universidade de São Paulo, EEFE-USP, R. Prof. Mello Moraes, 65, São Paulo, SP, CEP 05508-030, Brazil
| | - Mireille Andriamihaja
- UMR Physiologie de la Nutrition et du Comportement Alimentaire, AgroParisTech, INRA, Université Paris-Saclay, 75005, Paris, France
| | - Francois Blachier
- UMR Physiologie de la Nutrition et du Comportement Alimentaire, AgroParisTech, INRA, Université Paris-Saclay, 75005, Paris, France.
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Gordon BS, Steiner JL, Williamson DL, Lang CH, Kimball SR. Emerging role for regulated in development and DNA damage 1 (REDD1) in the regulation of skeletal muscle metabolism. Am J Physiol Endocrinol Metab 2016; 311:E157-74. [PMID: 27189933 PMCID: PMC4967146 DOI: 10.1152/ajpendo.00059.2016] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Accepted: 05/11/2016] [Indexed: 12/25/2022]
Abstract
Since its discovery, the protein regulated in development and DNA damage 1 (REDD1) has been implicated in the cellular response to various stressors. Most notably, its role as a repressor of signaling through the central metabolic regulator, the mechanistic target of rapamycin in complex 1 (mTORC1) has gained considerable attention. Not surprisingly, changes in REDD1 mRNA and protein have been observed in skeletal muscle under various physiological conditions (e.g., nutrient consumption and resistance exercise) and pathological conditions (e.g., sepsis, alcoholism, diabetes, obesity) suggesting a role for REDD1 in regulating mTORC1-dependent skeletal muscle protein metabolism. Our understanding of the causative role of REDD1 in skeletal muscle metabolism is increasing mostly due to the availability of genetically modified mice in which the REDD1 gene is disrupted. Results from such studies provide support for an important role for REDD1 in the regulation of mTORC1 as well as reveal unexplored functions of this protein in relation to other aspects of skeletal muscle metabolism. The goal of this work is to provide a comprehensive review of the role of REDD1 (and its paralog REDD2) in skeletal muscle during both physiological and pathological conditions.
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Affiliation(s)
- Bradley S Gordon
- Institute of Exercise Physiology and Wellness, The University of Central Florida, Orlando, Florida;
| | - Jennifer L Steiner
- Department of Cellular and Molecular Physiology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania; and
| | - David L Williamson
- Department of Exercise and Nutrition Sciences, University at Buffalo, Buffalo, New York
| | - Charles H Lang
- Department of Cellular and Molecular Physiology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania; and
| | - Scot R Kimball
- Department of Cellular and Molecular Physiology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania; and
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The Mechanistic Target of Rapamycin: The Grand ConducTOR of Metabolism and Aging. Cell Metab 2016; 23:990-1003. [PMID: 27304501 PMCID: PMC4910876 DOI: 10.1016/j.cmet.2016.05.009] [Citation(s) in RCA: 367] [Impact Index Per Article: 45.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Revised: 05/17/2016] [Accepted: 05/24/2016] [Indexed: 12/21/2022]
Abstract
Since the discovery that rapamycin, a small molecule inhibitor of the protein kinase mTOR (mechanistic target of rapamycin), can extend the lifespan of model organisms including mice, interest in understanding the physiological role and molecular targets of this pathway has surged. While mTOR was already well known as a regulator of growth and protein translation, it is now clear that mTOR functions as a central coordinator of organismal metabolism in response to both environmental and hormonal signals. This review discusses recent developments in our understanding of how mTOR signaling is regulated by nutrients and the role of the mTOR signaling pathway in key metabolic tissues. Finally, we discuss the molecular basis for the negative metabolic side effects associated with rapamycin treatment, which may serve as barriers to the adoption of rapamycin or similar compounds for the treatment of diseases of aging and metabolism.
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