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McKenna CF, Askow AT, Paulussen KJM, Salvador AF, Fang HY, Ulanov AV, Li Z, Paluska SA, Beals JW, Jäger R, Purpura M, Burd NA. Postabsorptive and postprandial myofibrillar protein synthesis rates at rest and after resistance exercise in women with postmenopause. J Appl Physiol (1985) 2024; 136:1388-1399. [PMID: 38385186 DOI: 10.1152/japplphysiol.00886.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Revised: 01/29/2024] [Accepted: 02/12/2024] [Indexed: 02/23/2024] Open
Abstract
Feeding and resistance exercise stimulate myofibrillar protein synthesis (MPS) rates in healthy adults. This anabolic characterization of "healthy adults" has been namely focused on males. Therefore, the purpose of this study was to examine the temporal responses of MPS and anabolic signaling to resistance exercise alone or combined with the ingestion of protein in postmenopausal females and compare postabsorptive rates with young females. Sixteen females [60 ± 7 yr; body mass index (BMI) = 26 ± 12 kg·m-2] completed an acute bout of unilateral resistance exercise before consuming either: a fortified whey protein supplement (WHEY) or water. Participants received primed continuous infusions of L-[ring-13C6]phenylalanine with bilateral muscle biopsies before and after treatment ingestion at 2 h and 4 h in nonexercised and exercised legs. Resistance exercise transiently increased MPS above baseline at 0-2 h in the water condition (P = 0.007). Feeding after resistance exercise resulted in a late phase (2-4 h) increase in MPS in the WHEY condition (P = 0.005). In both conditions, resistance exercise did not enhance the cumulative (0-4 h) MPS response. In the nonexercised leg, MPS did not differ at 0-2 h, 2-4 h, or 0-4 h of the measurement periods (all, P > 0.05). Likewise, there were no changes in the phosphorylation of p70S6K, AMPKα, or total and phosphorylated yes-associated protein on Ser127. Finally, postabsorptive MPS was lower in premenopausal versus postmenopausal females (P = 0.023). Our results demonstrate that resistance exercise-induced changes in MPS are temporally regulated, but do not result in greater cumulative (0-4 h) MPS in postmenopausal women.NEW & NOTEWORTHY An adequate quality and quantity of skeletal muscle is relevant to support physical performance and metabolic health. Muscle protein synthesis (MPS) is an established remodeling marker, which can be hypertrophic or nonhypertrophic. Importantly, protein ingestion and resistance exercise are two strategies that support healthy muscle by stimulating MPS. Our study shows postmenopause modulates baseline MPS that may diminish the MPS response to the fundamental anabolic stimuli of protein ingestion and resistance exercise in older females.
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Affiliation(s)
- Colleen F McKenna
- Division of Nutritional Sciences, University of Illinois Urbana-Champaign, Urbana, Illinois, United States
| | - Andrew T Askow
- Department of Kinesiology and Community Health, University of Illinois Urbana-Champaign, Urbana, Illinois, United States
| | - Kevin J M Paulussen
- Department of Kinesiology and Community Health, University of Illinois Urbana-Champaign, Urbana, Illinois, United States
| | - Amadeo F Salvador
- Department of Kinesiology and Community Health, University of Illinois Urbana-Champaign, Urbana, Illinois, United States
| | - Hsin-Yu Fang
- Department of Kinesiology and Community Health, University of Illinois Urbana-Champaign, Urbana, Illinois, United States
| | - Alexander V Ulanov
- Roy J. Carver Biotechnology Center, University of Illinois Urbana-Champaign, Urbana, Illinois, United States
| | - Zhong Li
- Roy J. Carver Biotechnology Center, University of Illinois Urbana-Champaign, Urbana, Illinois, United States
| | - Scott A Paluska
- Department of Kinesiology and Community Health, University of Illinois Urbana-Champaign, Urbana, Illinois, United States
| | - Joseph W Beals
- Division of Nutritional Sciences, University of Illinois Urbana-Champaign, Urbana, Illinois, United States
| | - Ralf Jäger
- Increnovo LLC, Milwaukee, Wisconsin, United States
| | | | - Nicholas A Burd
- Division of Nutritional Sciences, University of Illinois Urbana-Champaign, Urbana, Illinois, United States
- Department of Kinesiology and Community Health, University of Illinois Urbana-Champaign, Urbana, Illinois, United States
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2
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Bahat G, Ozkok S. The Current Landscape of Pharmacotherapies for Sarcopenia. Drugs Aging 2024; 41:83-112. [PMID: 38315328 DOI: 10.1007/s40266-023-01093-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/28/2023] [Indexed: 02/07/2024]
Abstract
Sarcopenia is a skeletal muscle disorder characterized by progressive and generalized decline in muscle mass and function. Although it is mostly known as an age-related disorder, it can also occur secondary to systemic diseases such as malignancy or organ failure. It has demonstrated a significant relationship with adverse outcomes, e.g., falls, disabilities, and even mortality. Several breakthroughs have been made to find a pharmaceutical therapy for sarcopenia over the years, and some have come up with promising findings. Yet still no drug has been approved for its treatment. The key factor that makes finding an effective pharmacotherapy so challenging is the general paradigm of standalone/single diseases, traditionally adopted in medicine. Today, it is well known that sarcopenia is a complex disorder caused by multiple factors, e.g., imbalance in protein turnover, satellite cell and mitochondrial dysfunction, hormonal changes, low-grade inflammation, senescence, anorexia of aging, and behavioral factors such as low physical activity. Therefore, pharmaceuticals, either alone or combined, that exhibit multiple actions on these factors simultaneously will likely be the drug of choice to manage sarcopenia. Among various drug options explored throughout the years, testosterone still has the most cumulated evidence regarding its effects on muscle health and its safety. A mas receptor agonist, BIO101, stands out as a recent promising pharmaceutical. In addition to the conventional strategies (i.e., nutritional support and physical exercise), therapeutics with multiple targets of action or combination of multiple therapeutics with different targets/modes of action appear to promise greater benefit for the prevention and treatment of sarcopenia.
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Affiliation(s)
- Gulistan Bahat
- Division of Geriatrics, Department of Internal Medicine, Istanbul Medical School, Istanbul University, Capa, 34390, Istanbul, Turkey.
| | - Serdar Ozkok
- Division of Geriatrics, Department of Internal Medicine, Hatay Training and Research Hospital, Hatay, 31040, Turkey
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3
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McColl TJ, Clarke DC. Kinetic modeling of leucine-mediated signaling and protein metabolism in human skeletal muscle. iScience 2024; 27:108634. [PMID: 38188514 PMCID: PMC10767222 DOI: 10.1016/j.isci.2023.108634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Revised: 11/15/2023] [Accepted: 12/01/2023] [Indexed: 01/09/2024] Open
Abstract
Skeletal muscle protein levels are governed by the relative rates of muscle protein synthesis (MPS) and breakdown (MPB). The mechanisms controlling these rates are complex, and their integrated behaviors are challenging to study through experiments alone. The purpose of this study was to develop and analyze a kinetic model of leucine-mediated mTOR signaling and protein metabolism in the skeletal muscle of young adults. Our model amalgamates published cellular-level models of the IRS1-PI3K-Akt-mTORC1 signaling system and of skeletal-muscle leucine kinetics with physiological-level models of leucine digestion and transport and insulin dynamics. The model satisfactorily predicts experimental data from diverse leucine feeding protocols. Model analysis revealed that total levels of p70S6K are a primary determinant of MPS, insulin signaling substantially affects muscle net protein balance via its effects on MPB, and p70S6K-mediated feedback of mTORC1 signaling reduces MPS in a dose-dependent manner.
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Affiliation(s)
- Taylor J. McColl
- Department of Biomedical Physiology and KinesiologySimon Fraser University, Burnaby, BC V5A 1S6, Canada
- Centre for Cell Biology, Development and Disease, Simon Fraser University, Burnaby, BC V5A 1S6, Canada
| | - David C. Clarke
- Department of Biomedical Physiology and KinesiologySimon Fraser University, Burnaby, BC V5A 1S6, Canada
- Centre for Cell Biology, Development and Disease, Simon Fraser University, Burnaby, BC V5A 1S6, Canada
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4
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Kataoka R, Hammert WB, Yamada Y, Song JS, Seffrin A, Kang A, Spitz RW, Wong V, Loenneke JP. The Plateau in Muscle Growth with Resistance Training: An Exploration of Possible Mechanisms. Sports Med 2024; 54:31-48. [PMID: 37787845 DOI: 10.1007/s40279-023-01932-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/01/2023] [Indexed: 10/04/2023]
Abstract
It is hypothesized that there is likely a finite ability for muscular adaptation. While it is difficult to distinguish between a true plateau following a long-term training period and short-term stalling in muscle growth, a plateau in muscle growth has been attributed to reaching a genetic potential, with limited discussion on what might physiologically contribute to this muscle growth plateau. The present paper explores potential physiological factors that may drive the decline in muscle growth after prolonged resistance training. Overall, with chronic training, the anabolic signaling pathways may become more refractory to loading. While measures of anabolic markers may have some predictive capabilities regarding muscle growth adaptation, they do not always demonstrate a clear connection. Catabolic processes may also constrain the ability to achieve further muscle growth, which is influenced by energy balance. Although speculative, muscle cells may also possess cell scaling mechanisms that sense and regulate their own size, along with molecular brakes that hinder growth rate over time. When considering muscle growth over the lifespan, there comes a point when the anabolic response is attenuated by aging, regardless of whether or not individuals approach their muscle growth potential. Our goal is that the current review opens avenues for future experimental studies to further elucidate potential mechanisms to explain why muscle growth may plateau.
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Affiliation(s)
- Ryo Kataoka
- Department of Health, Exercise Science, and Recreation Management, Kevser Ermin Applied Physiology Laboratory, The University of Mississippi, P.O. Box 1848, University, MS, 38677, USA
| | - William B Hammert
- Department of Health, Exercise Science, and Recreation Management, Kevser Ermin Applied Physiology Laboratory, The University of Mississippi, P.O. Box 1848, University, MS, 38677, USA
| | - Yujiro Yamada
- Department of Health, Exercise Science, and Recreation Management, Kevser Ermin Applied Physiology Laboratory, The University of Mississippi, P.O. Box 1848, University, MS, 38677, USA
| | - Jun Seob Song
- Department of Health, Exercise Science, and Recreation Management, Kevser Ermin Applied Physiology Laboratory, The University of Mississippi, P.O. Box 1848, University, MS, 38677, USA
| | - Aldo Seffrin
- Department of Health, Exercise Science, and Recreation Management, Kevser Ermin Applied Physiology Laboratory, The University of Mississippi, P.O. Box 1848, University, MS, 38677, USA
| | - Anna Kang
- Department of Health, Exercise Science, and Recreation Management, Kevser Ermin Applied Physiology Laboratory, The University of Mississippi, P.O. Box 1848, University, MS, 38677, USA
| | - Robert W Spitz
- Department of Health, Exercise Science, and Recreation Management, Kevser Ermin Applied Physiology Laboratory, The University of Mississippi, P.O. Box 1848, University, MS, 38677, USA
| | - Vickie Wong
- Department of Health, Exercise Science, and Recreation Management, Kevser Ermin Applied Physiology Laboratory, The University of Mississippi, P.O. Box 1848, University, MS, 38677, USA
| | - Jeremy P Loenneke
- Department of Health, Exercise Science, and Recreation Management, Kevser Ermin Applied Physiology Laboratory, The University of Mississippi, P.O. Box 1848, University, MS, 38677, USA.
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5
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Elliehausen CJ, Anderson RM, Diffee GM, Rhoads TW, Lamming DW, Hornberger TA, Konopka AR. Geroprotector drugs and exercise: friends or foes on healthy longevity? BMC Biol 2023; 21:287. [PMID: 38066609 PMCID: PMC10709984 DOI: 10.1186/s12915-023-01779-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Accepted: 11/23/2023] [Indexed: 12/18/2023] Open
Abstract
Physical activity and several pharmacological approaches individually combat age-associated conditions and extend healthy longevity in model systems. It is tantalizing to extrapolate that combining geroprotector drugs with exercise could extend healthy longevity beyond any individual treatment. However, the current dogma suggests that taking leading geroprotector drugs on the same day as exercise may limit several health benefits. Here, we review leading candidate geroprotector drugs and their interactions with exercise and highlight salient gaps in knowledge that need to be addressed to identify if geroprotector drugs can have a harmonious relationship with exercise.
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Affiliation(s)
- Christian J Elliehausen
- Division of Geriatrics and Gerontology, Department of Medicine, University of Wisconsin-Madison, Madison, WI, USA
- Geriatric Research, Education, and Clinical Center, William S. Middleton Memorial Veterans Hospital, Madison, WI, USA
| | - Rozalyn M Anderson
- Division of Geriatrics and Gerontology, Department of Medicine, University of Wisconsin-Madison, Madison, WI, USA
- Geriatric Research, Education, and Clinical Center, William S. Middleton Memorial Veterans Hospital, Madison, WI, USA
| | - Gary M Diffee
- Department of Kinesiology, University of Wisconsin-Madison, Madison, WI, USA
| | - Timothy W Rhoads
- Department of Nutritional Sciences, University of Wisconsin-Madison, Madison, WI, USA
- Division of Endocrinology, Department of Medicine, University of Wisconsin-Madison, Madison, WI, USA
| | - Dudley W Lamming
- William S. Middleton Memorial Veterans Hospital, Madison, WI, USA
| | - Troy A Hornberger
- Department of Comparative Biosciences, University of Wisconsin-Madison, Madison, WI, USA
| | - Adam R Konopka
- Division of Geriatrics and Gerontology, Department of Medicine, University of Wisconsin-Madison, Madison, WI, USA.
- Geriatric Research, Education, and Clinical Center, William S. Middleton Memorial Veterans Hospital, Madison, WI, USA.
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6
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O'Reilly CL, Bodine SC, Miller BF. Current limitations and future opportunities of tracer studies of muscle ageing. J Physiol 2023. [PMID: 38051758 DOI: 10.1113/jp285616] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Accepted: 11/22/2023] [Indexed: 12/07/2023] Open
Affiliation(s)
- Colleen L O'Reilly
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | - Sue C Bodine
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
- Oklahoma City Veterans Association, Oklahoma City, OK, USA
| | - Benjamin F Miller
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
- Oklahoma City Veterans Association, Oklahoma City, OK, USA
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7
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Granic A, Suetterlin K, Shavlakadze T, Grounds M, Sayer A. Hallmarks of ageing in human skeletal muscle and implications for understanding the pathophysiology of sarcopenia in women and men. Clin Sci (Lond) 2023; 137:1721-1751. [PMID: 37986616 PMCID: PMC10665130 DOI: 10.1042/cs20230319] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 11/01/2023] [Accepted: 11/14/2023] [Indexed: 11/22/2023]
Abstract
Ageing is a complex biological process associated with increased morbidity and mortality. Nine classic, interdependent hallmarks of ageing have been proposed involving genetic and biochemical pathways that collectively influence ageing trajectories and susceptibility to pathology in humans. Ageing skeletal muscle undergoes profound morphological and physiological changes associated with loss of strength, mass, and function, a condition known as sarcopenia. The aetiology of sarcopenia is complex and whilst research in this area is growing rapidly, there is a relative paucity of human studies, particularly in older women. Here, we evaluate how the nine classic hallmarks of ageing: genomic instability, telomere attrition, epigenetic alterations, loss of proteostasis, deregulated nutrient sensing, mitochondrial dysfunction, cellular senescence, stem cell exhaustion, and altered intercellular communication contribute to skeletal muscle ageing and the pathophysiology of sarcopenia. We also highlight five novel hallmarks of particular significance to skeletal muscle ageing: inflammation, neural dysfunction, extracellular matrix dysfunction, reduced vascular perfusion, and ionic dyshomeostasis, and discuss how the classic and novel hallmarks are interconnected. Their clinical relevance and translational potential are also considered.
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Affiliation(s)
- Antoneta Granic
- AGE Research Group, Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, U.K
- NIHR Newcastle Biomedical Research Centre, Newcastle University and Newcastle Upon Tyne Hospitals NHS Foundation Trust, Newcastle Upon Tyne, U.K
| | - Karen Suetterlin
- AGE Research Group, Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, U.K
- NIHR Newcastle Biomedical Research Centre, Newcastle University and Newcastle Upon Tyne Hospitals NHS Foundation Trust, Newcastle Upon Tyne, U.K
- John Walton Muscular Dystrophy Research Centre, Institute of Genetic Medicine, Newcastle University, Centre for Life, Newcastle upon Tyne, U.K
| | - Tea Shavlakadze
- Regeneron Pharmaceuticals Inc., Tarrytown, New York, NY, U.S.A
| | - Miranda D. Grounds
- Department of Anatomy, Physiology and Human Biology, School of Human Sciences, the University of Western Australia, Perth, WA 6009, Australia
| | - Avan A. Sayer
- AGE Research Group, Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, U.K
- NIHR Newcastle Biomedical Research Centre, Newcastle University and Newcastle Upon Tyne Hospitals NHS Foundation Trust, Newcastle Upon Tyne, U.K
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8
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Callaway CS, Mouchantat LM, Bitler BG, Bonetto A. Mechanisms of Ovarian Cancer-Associated Cachexia. Endocrinology 2023; 165:bqad176. [PMID: 37980602 PMCID: PMC10699881 DOI: 10.1210/endocr/bqad176] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Revised: 11/02/2023] [Accepted: 11/15/2023] [Indexed: 11/21/2023]
Abstract
Cancer-associated cachexia occurs in 50% to 80% of cancer patients and is responsible for 20% to 30% of cancer-related deaths. Cachexia limits survival and treatment outcomes, and is a major contributor to morbidity and mortality during cancer. Ovarian cancer is one of the leading causes of cancer-related deaths in women, and recent studies have begun to highlight the prevalence and clinical impact of cachexia in this population. Here, we review the existing understanding of cachexia pathophysiology and summarize relevant studies assessing ovarian cancer-associated cachexia in clinical and preclinical studies. In clinical studies, there is increased evidence that reduced skeletal muscle mass and quality associate with worse outcomes in subjects with ovarian cancer. Mouse models of ovarian cancer display cachexia, often characterized by muscle and fat wasting alongside inflammation, although they remain underexplored relative to other cachexia-associated cancer types. Certain soluble factors have been identified and successfully targeted in these models, providing novel therapeutic targets for mitigating cachexia during ovarian cancer. However, given the relatively low number of studies, the translational relevance of these findings is yet to be determined and requires more research. Overall, our current understanding of ovarian cancer-associated cachexia is insufficient and this review highlights the need for future research specifically aimed at exploring mechanisms of ovarian cancer-associated cachexia by using unbiased approaches and animal models representative of the clinical landscape of ovarian cancer.
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Affiliation(s)
- Chandler S Callaway
- Department of Pathology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Lila M Mouchantat
- Department of Pathology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Benjamin G Bitler
- Department of Obstetrics & Gynecology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
- Comprehensive Cancer Center, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Andrea Bonetto
- Department of Pathology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
- Comprehensive Cancer Center, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
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9
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Konopka AR, Lamming DW. Blazing a trail for the clinical use of rapamycin as a geroprotecTOR. GeroScience 2023; 45:2769-2783. [PMID: 37801202 PMCID: PMC10643772 DOI: 10.1007/s11357-023-00935-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Accepted: 09/04/2023] [Indexed: 10/07/2023] Open
Abstract
Treatment with rapamycin, an inhibitor of the mechanistic Target Of Rapamycin Complex One (mTORC1) protein kinase, has been repeatedly demonstrated to extend lifespan and prevent or delay age-related diseases in diverse model systems. Concerns over the risk of potentially serious side effects in humans, including immunosuppression and metabolic disruptions, have cautiously limited the translation of rapamycin and its analogs as a treatment for aging associated conditions. During the last decade, we and others have developed a working model that suggests that while inhibition of mTORC1 promotes healthy aging, many of the negative side effects of rapamycin are associated with "off-target" inhibition of a second mTOR complex, mTORC2. Differences in the kinetics and molecular mechanisms by which rapamycin inhibits mTORC1 and mTORC2 suggest that a therapeutic window for rapamycin could be exploited using intermittent dosing schedules or alternative rapalogs that may enable more selective inhibition of mTORC1. However, the optimal dosing schedules and the long-term efficacy of such interventions in humans are unknown. Here, we highlight ongoing or upcoming clinical trials that will address outstanding questions regarding the safety, pharmacokinetics, pharmacodynamics, and efficacy of rapamycin and rapalogs on several clinically oriented outcomes. Results from these early phase studies will help guide the design of phase 3 clinical trials to determine whether rapamycin can be used safely to inhibit mTORC1 for the treatment and prevention of age-related diseases in humans.
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Affiliation(s)
- Adam R Konopka
- Division of Geriatrics, Department of Medicine, University of Wisconsin-Madison, Madison, WI, 53705, USA.
- William S. Middleton Memorial Veterans Hospital, Madison, WI, 53705, USA.
- Division of Geriatrics and Gerontology, Department of Medicine, Geriatric Research Education and Clinical Center (GRECC), William S. Middleton Memorial Veterans Hospital, University of Wisconsin-Madison, 2500 Overlook Terrace, Madison, WI, 53705, USA.
| | - Dudley W Lamming
- William S. Middleton Memorial Veterans Hospital, Madison, WI, 53705, USA
- Division of Endocrinology, Department of Medicine, University of Wisconsin-Madison, Madison, WI, 53705, USA
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10
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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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11
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Reidy PT, Borack MS, Dickinson JM, Carroll CC, Burd NA, Drummond MJ, Fry CS, Lambert BS, Gundermann DM, Glynn EL, Markofski MM, Timmerman KL, Moro T, Volpi E, Trappe S, Trappe TA, Harber MP, Rasmussen BB. Postabsorptive muscle protein synthesis is higher in outpatients as compared to inpatients. Am J Physiol Endocrinol Metab 2023; 325:E113-E118. [PMID: 37315157 PMCID: PMC10393319 DOI: 10.1152/ajpendo.00144.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Revised: 06/05/2023] [Accepted: 06/06/2023] [Indexed: 06/16/2023]
Abstract
Several factors affect muscle protein synthesis (MPS) in the postabsorptive state. Extreme physical inactivity (e.g., bedrest) may reduce basal MPS, whereas walking may augment basal MPS. We hypothesized that outpatients would have a higher postabsorptive MPS than inpatients. To test this hypothesis, we conducted a retrospective analysis. We compared 152 outpatient participants who arrived at the research site the morning of the MPS assessment with 350 Inpatient participants who had an overnight stay in the hospital unit before the MPS assessment the following morning. We used stable isotopic methods and collected vastus lateralis biopsies ∼2 to 3 h apart to assess mixed MPS. MPS was ∼12% higher (P < 0.05) for outpatients than inpatients. Within a subset of participants, we discovered that after instruction to limit activity, outpatients (n = 13) took 800 to 900 steps in the morning to arrive at the unit, seven times more steps than inpatients (n = 12). We concluded that an overnight stay in the hospital as an inpatient is characterized by reduced morning activity and causes a slight but significant reduction in MPS compared with participants studied as outpatients. Researchers should be aware of physical activity status when designing and interpreting MPS results.NEW & NOTEWORTHY The postabsorptive muscle protein synthesis rate is lower in the morning after an overnight inpatient hospital stay compared with an outpatient visit. Although only a minimal amount of steps was conducted by outpatients (∼900), this was enough to increase postabsorptive muscle protein synthesis rate.
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Affiliation(s)
- Paul T Reidy
- Center for Metabolic Health, University of Texas Medical Branch, Galveston, Texas, United States
- Department of Kinesiology, Nutrition and Health, Miami University, Oxford, Ohio, United States
| | - Michael S Borack
- Center for Metabolic Health, University of Texas Medical Branch, Galveston, Texas, United States
| | - Jared M Dickinson
- Center for Metabolic Health, University of Texas Medical Branch, Galveston, Texas, United States
| | - Chad C Carroll
- Human Performance Laboratory, Ball State University, Muncie, Indiana, United States
| | - Nicholas A Burd
- Human Performance Laboratory, Ball State University, Muncie, Indiana, United States
| | - Micah J Drummond
- Department of Physical Therapy & Athletic Training, University of Utah, Salt Lake City, Utah, United States
- Molecular Medicine Program, University of Utah, Salt Lake City, Utah, United States
| | - Christopher S Fry
- Center for Metabolic Health, University of Texas Medical Branch, Galveston, Texas, United States
- Sealy Center on Aging, University of Texas Medical Branch, Galveston, Texas, United States
| | - Bradley S Lambert
- Center for Metabolic Health, University of Texas Medical Branch, Galveston, Texas, United States
| | - David M Gundermann
- Center for Metabolic Health, University of Texas Medical Branch, Galveston, Texas, United States
| | - Erin L Glynn
- Center for Metabolic Health, University of Texas Medical Branch, Galveston, Texas, United States
| | - Melissa M Markofski
- Sealy Center on Aging, University of Texas Medical Branch, Galveston, Texas, United States
| | - Kyle L Timmerman
- Department of Internal Medicine/Geriatrics, University of Texas Medical Branch, Galveston, Texas, United States
| | - Tatiana Moro
- Sealy Center on Aging, University of Texas Medical Branch, Galveston, Texas, United States
| | - Elena Volpi
- Sealy Center on Aging, University of Texas Medical Branch, Galveston, Texas, United States
- Department of Internal Medicine/Geriatrics, University of Texas Medical Branch, Galveston, Texas, United States
| | - Scott Trappe
- Human Performance Laboratory, Ball State University, Muncie, Indiana, United States
| | - Todd A Trappe
- Human Performance Laboratory, Ball State University, Muncie, Indiana, United States
| | - Matthew P Harber
- Human Performance Laboratory, Ball State University, Muncie, Indiana, United States
| | - Blake B Rasmussen
- Center for Metabolic Health, University of Texas Medical Branch, Galveston, Texas, United States
- Sealy Center on Aging, University of Texas Medical Branch, Galveston, Texas, United States
- Department of Biochemistry & Molecular Biology, University of Texas Medical Branch, Galveston, Texas, United States
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12
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Posey EA, Davis TA. Review: Nutritional regulation of muscle growth in neonatal swine. Animal 2023; 17 Suppl 3:100831. [PMID: 37263816 PMCID: PMC10621894 DOI: 10.1016/j.animal.2023.100831] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 12/31/2022] [Accepted: 01/06/2023] [Indexed: 06/03/2023] Open
Abstract
Despite advances in the nutritional support of low birth weight and early-weaned piglets, most experience reduced extrauterine growth performance. To further optimize nutritional support and develop targeted intervention strategies, the mechanisms that regulate the anabolic response to nutrition must be fully understood. Knowledge gained in these studies represents a valuable intersection of agriculture and biomedical research, as low birth weight and early-weaned piglets face many of the same morbidities as preterm and low birth weight infants, including extrauterine growth faltering and reduced lean growth. While the reasons for poor growth performance are multifaceted, recent studies have increased our understanding of the role of nutrition in the regulation of skeletal muscle growth in the piglet. The purpose of this review is to summarize the published literature surrounding advances in the current understanding of the anabolic signaling that occurs after a meal and how this response is developmentally regulated in the neonatal pig. It will focus on the regulation of protein synthesis, and especially the upstream and downstream effectors surrounding the master protein kinase, mechanistic target of rapamycin complex 1 (mTORC1) that controls translation initiation. It also will examine the regulatory pathways associated with the postprandial anabolic agents, insulin and specific amino acids, that are upstream of mTORC1 and lead to its activation. Lastly, the integration of upstream signaling cascades by mTORC1 leading to the activation of translation initiation factors that regulate protein synthesis will be discussed. This review concludes that anabolic signaling cascades are stimulated by both insulin and amino acids, especially leucine, through separate pathways upstream of mTORC1, and that these stimulatory pathways result in mTORC1 activation and subsequent activation of downstream effectors that regulate translation initiation Additionally, it is concluded that this anabolic response is unique to the skeletal muscle of the neonate, resulting from increased sensitivity to the rise in both insulin and amino acid after a meal. However, this response is dampened in skeletal muscle of the low birth weight pig, indicative of anabolic resistance. Elucidation of the pathways and regulatory mechanisms surrounding protein synthesis and lean growth allow for the development of potential targeted therapeutics and intervention strategies both in livestock production and neonatal care.
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Affiliation(s)
- E A Posey
- United States Department of Agriculture/Agricultural Research Service Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA
| | - T A Davis
- United States Department of Agriculture/Agricultural Research Service Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA.
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13
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Connolly G, Hudson JL, Bergia RE, Davis EM, Hartman AS, Zhu W, Carroll CC, Campbell WW. Effects of Consuming Ounce-Equivalent Portions of Animal- vs. Plant-Based Protein Foods, as Defined by the Dietary Guidelines for Americans on Essential Amino Acids Bioavailability in Young and Older Adults: Two Cross-Over Randomized Controlled Trials. Nutrients 2023; 15:2870. [PMID: 37447197 DOI: 10.3390/nu15132870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Revised: 06/21/2023] [Accepted: 06/23/2023] [Indexed: 07/15/2023] Open
Abstract
BACKGROUND The Dietary Guidelines for Americans (DGA) recommends consuming a variety of "Protein Foods" based on "ounce-equivalent" (oz-eq) portions. No study has assessed the same oz-eq portions of animal- vs. plant-based protein foods on essential amino acid (EAA) bioavailability for protein anabolism in young and older adults. OBJECTIVES We assessed the effects of consuming two oz-eq portions of pork, eggs, black beans, and almonds on postprandial EAA bioavailability in young and older adults. METHODS We conducted two investigator-blinded, randomized crossover trials in young (n = 30; mean age ± SD: 26.0 ± 4.9 y) and older adults (n = 25; mean age ± SD: 64.2 ± 6.6 y). Participants completed four testing sessions where they consumed a standardized meal with two oz-eq of either unprocessed lean pork, whole eggs, black beans, or sliced almonds. Blood samples were taken at baseline and 30, 60, 120, 180, 240, and 300 min postprandially. Plasma EAA bioavailability was based on postprandial integrated positive areas under the curve. RESULTS Participant age did not affect EAA bioavailability among the four protein foods tested. Two oz-eq portions of pork (7.36 g EAA) and eggs (5.38 g EAA) resulted in greater EAA bioavailability than black beans (3.02 g EAA) and almonds (1.85 g EAA) in young and older adults, separately or combined (p < 0.0001 for all). Pork resulted in greater EAA bioavailability than eggs in young adults (p < 0.0001), older adults (p = 0.0007), and combined (p < 0.0001). There were no differences in EAA bioavailability between black beans and almonds. CONCLUSIONS The same "oz-eq" portions of animal- and plant-based protein foods do not provide equivalent EAA content and postprandial bioavailability for protein anabolism in young and older adults.
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Affiliation(s)
- Gavin Connolly
- Department of Nutrition Science, Purdue University, West Lafayette, IN 47907, USA
| | - Joshua L Hudson
- Department of Nutrition Science, Purdue University, West Lafayette, IN 47907, USA
| | - Robert E Bergia
- Department of Nutrition Science, Purdue University, West Lafayette, IN 47907, USA
| | - Eric M Davis
- Department of Nutrition Science, Purdue University, West Lafayette, IN 47907, USA
| | - Austin S Hartman
- Department of Statistics, Purdue University, West Lafayette, IN 47907, USA
| | - Wenbin Zhu
- Department of Statistics, Purdue University, West Lafayette, IN 47907, USA
| | - Chad C Carroll
- Department of Health and Kinesiology, Purdue University, West Lafayette, IN 47907, USA
| | - Wayne W Campbell
- Department of Nutrition Science, Purdue University, West Lafayette, IN 47907, USA
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14
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Mannick JB, Lamming DW. Targeting the biology of aging with mTOR inhibitors. NATURE AGING 2023; 3:642-660. [PMID: 37142830 PMCID: PMC10330278 DOI: 10.1038/s43587-023-00416-y] [Citation(s) in RCA: 25] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Accepted: 04/07/2023] [Indexed: 05/06/2023]
Abstract
Inhibition of the protein kinase mechanistic target of rapamycin (mTOR) with the Food and Drug Administration (FDA)-approved therapeutic rapamycin promotes health and longevity in diverse model organisms. More recently, specific inhibition of mTORC1 to treat aging-related conditions has become the goal of basic and translational scientists, clinicians and biotechnology companies. Here, we review the effects of rapamycin on the longevity and survival of both wild-type mice and mouse models of human diseases. We discuss recent clinical trials that have explored whether existing mTOR inhibitors can safely prevent, delay or treat multiple diseases of aging. Finally, we discuss how new molecules may provide routes to the safer and more selective inhibition of mTOR complex 1 (mTORC1) in the decade ahead. We conclude by discussing what work remains to be done and the questions that will need to be addressed to make mTOR inhibitors part of the standard of care for diseases of aging.
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Affiliation(s)
| | - Dudley W Lamming
- Department of Medicine, University of Wisconsin-Madison, Madison, WI, USA.
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15
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Zhong Q, Xiao X, Qiu Y, Xu Z, Chen C, Chong B, Zhao X, Hai S, Li S, An Z, Dai L. Protein posttranslational modifications in health and diseases: Functions, regulatory mechanisms, and therapeutic implications. MedComm (Beijing) 2023; 4:e261. [PMID: 37143582 PMCID: PMC10152985 DOI: 10.1002/mco2.261] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2022] [Revised: 03/26/2023] [Accepted: 03/27/2023] [Indexed: 05/06/2023] Open
Abstract
Protein posttranslational modifications (PTMs) refer to the breaking or generation of covalent bonds on the backbones or amino acid side chains of proteins and expand the diversity of proteins, which provides the basis for the emergence of organismal complexity. To date, more than 650 types of protein modifications, such as the most well-known phosphorylation, ubiquitination, glycosylation, methylation, SUMOylation, short-chain and long-chain acylation modifications, redox modifications, and irreversible modifications, have been described, and the inventory is still increasing. By changing the protein conformation, localization, activity, stability, charges, and interactions with other biomolecules, PTMs ultimately alter the phenotypes and biological processes of cells. The homeostasis of protein modifications is important to human health. Abnormal PTMs may cause changes in protein properties and loss of protein functions, which are closely related to the occurrence and development of various diseases. In this review, we systematically introduce the characteristics, regulatory mechanisms, and functions of various PTMs in health and diseases. In addition, the therapeutic prospects in various diseases by targeting PTMs and associated regulatory enzymes are also summarized. This work will deepen the understanding of protein modifications in health and diseases and promote the discovery of diagnostic and prognostic markers and drug targets for diseases.
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Affiliation(s)
- Qian Zhong
- Department of Endocrinology and MetabolismGeneral Practice Ward/International Medical Center WardGeneral Practice Medical Center and National Clinical Research Center for GeriatricsState Key Laboratory of BiotherapyWest China Hospital, Sichuan UniversityChengduChina
| | - Xina Xiao
- Department of Endocrinology and MetabolismGeneral Practice Ward/International Medical Center WardGeneral Practice Medical Center and National Clinical Research Center for GeriatricsState Key Laboratory of BiotherapyWest China Hospital, Sichuan UniversityChengduChina
| | - Yijie Qiu
- Department of Endocrinology and MetabolismGeneral Practice Ward/International Medical Center WardGeneral Practice Medical Center and National Clinical Research Center for GeriatricsState Key Laboratory of BiotherapyWest China Hospital, Sichuan UniversityChengduChina
| | - Zhiqiang Xu
- Department of Endocrinology and MetabolismGeneral Practice Ward/International Medical Center WardGeneral Practice Medical Center and National Clinical Research Center for GeriatricsState Key Laboratory of BiotherapyWest China Hospital, Sichuan UniversityChengduChina
| | - Chunyu Chen
- Department of Endocrinology and MetabolismGeneral Practice Ward/International Medical Center WardGeneral Practice Medical Center and National Clinical Research Center for GeriatricsState Key Laboratory of BiotherapyWest China Hospital, Sichuan UniversityChengduChina
| | - Baochen Chong
- Department of Endocrinology and MetabolismGeneral Practice Ward/International Medical Center WardGeneral Practice Medical Center and National Clinical Research Center for GeriatricsState Key Laboratory of BiotherapyWest China Hospital, Sichuan UniversityChengduChina
| | - Xinjun Zhao
- Department of Endocrinology and MetabolismGeneral Practice Ward/International Medical Center WardGeneral Practice Medical Center and National Clinical Research Center for GeriatricsState Key Laboratory of BiotherapyWest China Hospital, Sichuan UniversityChengduChina
| | - Shan Hai
- Department of Endocrinology and MetabolismGeneral Practice Ward/International Medical Center WardGeneral Practice Medical Center and National Clinical Research Center for GeriatricsState Key Laboratory of BiotherapyWest China Hospital, Sichuan UniversityChengduChina
| | - Shuangqing Li
- Department of Endocrinology and MetabolismGeneral Practice Ward/International Medical Center WardGeneral Practice Medical Center and National Clinical Research Center for GeriatricsState Key Laboratory of BiotherapyWest China Hospital, Sichuan UniversityChengduChina
| | - Zhenmei An
- Department of Endocrinology and MetabolismGeneral Practice Ward/International Medical Center WardGeneral Practice Medical Center and National Clinical Research Center for GeriatricsState Key Laboratory of BiotherapyWest China Hospital, Sichuan UniversityChengduChina
| | - Lunzhi Dai
- Department of Endocrinology and MetabolismGeneral Practice Ward/International Medical Center WardGeneral Practice Medical Center and National Clinical Research Center for GeriatricsState Key Laboratory of BiotherapyWest China Hospital, Sichuan UniversityChengduChina
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16
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Setiawan T, Sari IN, Wijaya YT, Julianto NM, Muhammad JA, Lee H, Chae JH, Kwon HY. Cancer cachexia: molecular mechanisms and treatment strategies. J Hematol Oncol 2023; 16:54. [PMID: 37217930 DOI: 10.1186/s13045-023-01454-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Accepted: 05/13/2023] [Indexed: 05/24/2023] Open
Abstract
Muscle wasting is a consequence of physiological changes or a pathology characterized by increased catabolic activity that leads to progressive loss of skeletal muscle mass and strength. Numerous diseases, including cancer, organ failure, infection, and aging-associated diseases, are associated with muscle wasting. Cancer cachexia is a multifactorial syndrome characterized by loss of skeletal muscle mass, with or without the loss of fat mass, resulting in functional impairment and reduced quality of life. It is caused by the upregulation of systemic inflammation and catabolic stimuli, leading to inhibition of protein synthesis and enhancement of muscle catabolism. Here, we summarize the complex molecular networks that regulate muscle mass and function. Moreover, we describe complex multi-organ roles in cancer cachexia. Although cachexia is one of the main causes of cancer-related deaths, there are still no approved drugs for cancer cachexia. Thus, we compiled recent ongoing pre-clinical and clinical trials and further discussed potential therapeutic approaches for cancer cachexia.
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Affiliation(s)
- Tania Setiawan
- Department of Integrated Biomedical Science, Soonchunhyang University, Cheonan-Si, 31151, Republic of Korea
| | - Ita Novita Sari
- Soonchunhyang Institute of Medi-Bio Science (SIMS), Soonchunhyang University, Cheonan-Si, 31151, Republic of Korea
- Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), 61 Biopolis Drive, Proteos, Singapore, 138673, Republic of Singapore
| | - Yoseph Toni Wijaya
- Department of Integrated Biomedical Science, Soonchunhyang University, Cheonan-Si, 31151, Republic of Korea
| | - Nadya Marcelina Julianto
- Department of Integrated Biomedical Science, Soonchunhyang University, Cheonan-Si, 31151, Republic of Korea
| | - Jabir Aliyu Muhammad
- Department of Integrated Biomedical Science, Soonchunhyang University, Cheonan-Si, 31151, Republic of Korea
| | - Hyeok Lee
- Department of Integrated Biomedical Science, Soonchunhyang University, Cheonan-Si, 31151, Republic of Korea
| | - Ji Heon Chae
- Department of Integrated Biomedical Science, Soonchunhyang University, Cheonan-Si, 31151, Republic of Korea
| | - Hyog Young Kwon
- Department of Integrated Biomedical Science, Soonchunhyang University, Cheonan-Si, 31151, Republic of Korea.
- Soonchunhyang Institute of Medi-Bio Science (SIMS), Soonchunhyang University, Cheonan-Si, 31151, Republic of Korea.
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17
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Marshall RN, Morgan PT, Smeuninx B, Quinlan JI, Brook MS, Atherton PJ, Smith K, Wilkinson DJ, Breen L. Myofibrillar Protein Synthesis and Acute Intracellular Signaling with Elastic Band Resistance Exercise in Young and Older Men. Med Sci Sports Exerc 2023; 55:398-408. [PMID: 36731005 DOI: 10.1249/mss.0000000000003061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
PURPOSE Resistance exercise training (RET) attenuates age-related muscle and strength loss ("sarcopenia"). However, compared with machine-based RET, the efficacy of cost-effective, accessible elastic band RET (EB-RET) for muscle adaptive remodeling lacks supporting mechanistic evidence. METHODS Eight young (YM; 24 ± 4 yr) and eight older (OM; 68 ± 6 yr) untrained males consumed an oral stable isotope tracer (D 2 O) combined with serial vastus lateralis muscle biopsies to measure integrated myofibrillar protein synthesis (iMyoPS) and regulatory signaling over ~48 h before (habitual) and after an acute bout of EB-RET (6 × 12 repetitions at ~70% of one-repetition maximum). iMyoPS was determined via gas chromatography-pyrolysis-isotope ratio mass spectroscopy and regulatory signaling expression by immunoblot. RESULTS Habitual iMyoPS did not differ between YM and OM (1.62% ± 0.21% vs 1.43% ± 0.47%·d -1 , respectively, P = 0.128). There was a significant increase in iMyoPS after EB-RET in YM (2.23% ± 0.69%·d -1 , P = 0.02), but not OM (1.75% ± 0.54%·d -1 , P = 0.30). EB-RET increased the phosphorylation of key anabolic signaling proteins similarly in YM and OM at 1 h postexercise, including p-IRS-1 Ser636/639 , p-Akt Ser473 , p-4EBP-1 Thr37/46 , p-P70S6K Thr389 , and p-RPS6 Ser240/244 , whereas p-TSC2 Thr1462 and p-mTOR Ser2448 increased only in YM (all P < 0.05). There were no differences in the expression of amino acid transporters/sensors or proteolytic markers after EB-RET. CONCLUSIONS iMyoPS was elevated after EB-RET in YM but not OM. However, the increase in acute anabolic signaling with EB-RET was largely similar between groups. In conclusion, the capacity for EB-RET to stimulate iMyoPS may be impaired in older age. Further work may be necessary to optimize prescriptive programming in YM and OM.
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18
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Crombie EM, Kim S, Adamson S, Dong H, Lu TC, Wu Y, Wu Y, Levy Y, Stimple N, Lam WMR, Hey HWD, Withers DJ, Hsu AL, Bay BH, Ochala J, Tsai SY. Activation of eIF4E-binding-protein-1 rescues mTORC1-induced sarcopenia by expanding lysosomal degradation capacity. J Cachexia Sarcopenia Muscle 2023; 14:198-213. [PMID: 36398408 PMCID: PMC9891956 DOI: 10.1002/jcsm.13121] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Revised: 09/01/2022] [Accepted: 10/10/2022] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Chronic mTORC1 activation in skeletal muscle is linked with age-associated loss of muscle mass and strength, known as sarcopenia. Genetic activation of mTORC1 by conditionally ablating mTORC1 upstream inhibitor TSC1 in skeletal muscle accelerates sarcopenia development in adult mice. Conversely, genetic suppression of mTORC1 downstream effectors of protein synthesis delays sarcopenia in natural aging mice. mTORC1 promotes protein synthesis by activating ribosomal protein S6 kinases (S6Ks) and inhibiting eIF4E-binding proteins (4EBPs). Whole-body knockout of S6K1 or muscle-specific over-expression of a 4EBP1 mutant transgene (4EBP1mt), which is resistant to mTORC1-mediated inhibition, ameliorates muscle loss with age and preserves muscle function by enhancing mitochondria activities, despite both transgenic mice showing retarded muscle growth at a young age. Why repression of mTORC1-mediated protein synthesis can mitigate progressive muscle atrophy and dysfunction with age remains unclear. METHODS Mice with myofiber-specific knockout of TSC1 (TSC1mKO), in which mTORC1 is hyperactivated in fully differentiated myofibers, were used as a mouse model of sarcopenia. To elucidate the role of mTORC1-mediated protein synthesis in regulating muscle mass and physiology, we bred the 4EBP1mt transgene or S6k1 floxed mice into the TSC1mKO mouse background to generate 4EBP1mt-TSC1mKO or S6K1-TSC1mKO mice, respectively. Functional and molecular analyses were performed to assess their role in sarcopenia development. RESULTS Here, we show that 4EBP1mt-TSC1mKO, but not S6K1-TSC1mKO, preserved muscle mass (36.7% increase compared with TSC1mKO, P < 0.001) and strength (36.8% increase compared with TSC1mKO, P < 0.01) at the level of control mice. Mechanistically, 4EBP1 activation suppressed aberrant protein synthesis (two-fold reduction compared with TSC1mKO, P < 0.05) and restored autophagy flux without relieving mTORC1-mediated inhibition of ULK1, an upstream activator of autophagosome initiation. We discovered a previously unidentified phenotype of lysosomal failure in TSC1mKO mouse muscle, in which the lysosomal defect was also conserved in the naturally aged mouse muscle, whereas 4EBP1 activation enhanced lysosomal protease activities to compensate for impaired autophagy induced by mTORC1 hyperactivity. Consequently, 4EBP1 activation relieved oxidative stress to prevent toxic aggregate accumulation (0.5-fold reduction compared with TSC1mKO, P < 0.05) in muscle and restored mitochondrial homeostasis and function. CONCLUSIONS We identify 4EBP1 as a communication hub coordinating protein synthesis and degradation to protect proteostasis, revealing therapeutic potential for activating lysosomal degradation to mitigate sarcopenia.
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Affiliation(s)
- Elisa M Crombie
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Seonyoung Kim
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Stuart Adamson
- Buck Institute for Research on Aging, Novato, California, USA
| | - Han Dong
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Tzu-Chiao Lu
- Research Center for Healthy Aging, China Medical University, Taichung, Taiwan
| | - Yiju Wu
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Yajun Wu
- Department of Anatomy, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Yotam Levy
- Centre of Human and Applied Physiological Sciences, School of Basic and Medical Biosciences, Faculty of Life Sciences & Medicine, King's College, London, UK
| | - Nolan Stimple
- Buck Institute for Research on Aging, Novato, California, USA
| | - Wing Moon R Lam
- Department of Orthopedic Surgery, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Hwee Weng D Hey
- Department of Orthopedic Surgery, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Dominic J Withers
- Metabolic Signalling Group, Medical Research Council London Institute of Medical Sciences (LMS), London, UK.,Institute of Clinical Sciences (ICS), Faculty of Medicine, Imperial College London, London, UK
| | - Ao-Lin Hsu
- Research Center for Healthy Aging, China Medical University, Taichung, Taiwan.,Institute of Biochemistry and Molecular Biology, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Boon Huat Bay
- Department of Anatomy, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Julien Ochala
- Centre of Human and Applied Physiological Sciences, School of Basic and Medical Biosciences, Faculty of Life Sciences & Medicine, King's College, London, UK.,Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Shih-Yin Tsai
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.,Healthy Longevity Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
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19
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van der Heijden I, Monteyne AJ, Stephens FB, Wall BT. Alternative dietary protein sources to support healthy and active skeletal muscle aging. Nutr Rev 2023; 81:206-230. [PMID: 35960188 DOI: 10.1093/nutrit/nuac049] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
To mitigate the age-related decline in skeletal muscle quantity and quality, and the associated negative health outcomes, it has been proposed that dietary protein recommendations for older adults should be increased alongside an active lifestyle and/or structured exercise training. Concomitantly, there are growing environmental concerns associated with the production of animal-based dietary protein sources. The question therefore arises as to where this dietary protein required for meeting the protein demands of the rapidly aging global population should (or could) be obtained. Various non-animal-derived protein sources possess favorable sustainability credentials, though much less is known (compared with animal-derived proteins) about their ability to influence muscle anabolism. It is also likely that the anabolic potential of various alternative protein sources varies markedly, with the majority of options remaining to be investigated. The purpose of this review was to thoroughly assess the current evidence base for the utility of alternative protein sources (plants, fungi, insects, algae, and lab-grown "meat") to support muscle anabolism in (active) older adults. The solid existing data portfolio requires considerable expansion to encompass the strategic evaluation of the various types of dietary protein sources. Such data will ultimately be necessary to support desirable alterations and refinements in nutritional guidelines to support healthy and active aging, while concomitantly securing a sustainable food future.
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Affiliation(s)
- Ino van der Heijden
- Department of Sport and Health Sciences, College of Life Environmental Sciences, University of Exeter, Exeter, United Kingdom
| | - Alistair J Monteyne
- Department of Sport and Health Sciences, College of Life Environmental Sciences, University of Exeter, Exeter, United Kingdom
| | - Francis B Stephens
- Department of Sport and Health Sciences, College of Life Environmental Sciences, University of Exeter, Exeter, United Kingdom
| | - Benjamin T Wall
- Department of Sport and Health Sciences, College of Life Environmental Sciences, University of Exeter, Exeter, United Kingdom
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20
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Paez HG, Pitzer CR, Alway SE. Age-Related Dysfunction in Proteostasis and Cellular Quality Control in the Development of Sarcopenia. Cells 2023; 12:cells12020249. [PMID: 36672183 PMCID: PMC9856405 DOI: 10.3390/cells12020249] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2022] [Revised: 01/04/2023] [Accepted: 01/04/2023] [Indexed: 01/11/2023] Open
Abstract
Sarcopenia is a debilitating skeletal muscle disease that accelerates in the last decades of life and is characterized by marked deficits in muscle strength, mass, quality, and metabolic health. The multifactorial causes of sarcopenia have proven difficult to treat and involve a complex interplay between environmental factors and intrinsic age-associated changes. It is generally accepted that sarcopenia results in a progressive loss of skeletal muscle function that exceeds the loss of mass, indicating that while loss of muscle mass is important, loss of muscle quality is the primary defect with advanced age. Furthermore, preclinical models have suggested that aged skeletal muscle exhibits defects in cellular quality control such as the degradation of damaged mitochondria. Recent evidence suggests that a dysregulation of proteostasis, an important regulator of cellular quality control, is a significant contributor to the aging-associated declines in muscle quality, function, and mass. Although skeletal muscle mammalian target of rapamycin complex 1 (mTORC1) plays a critical role in cellular control, including skeletal muscle hypertrophy, paradoxically, sustained activation of mTORC1 recapitulates several characteristics of sarcopenia. Pharmaceutical inhibition of mTORC1 as well as caloric restriction significantly improves muscle quality in aged animals, however, the mechanisms controlling cellular proteostasis are not fully known. This information is important for developing effective therapeutic strategies that mitigate or prevent sarcopenia and associated disability. This review identifies recent and historical understanding of the molecular mechanisms of proteostasis driving age-associated muscle loss and suggests potential therapeutic interventions to slow or prevent sarcopenia.
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Affiliation(s)
- Hector G. Paez
- Department of Physiology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN 38163, USA
- Integrated Biomedical Sciences Graduate Program, College of Graduate Health Sciences, University of Tennessee Health Science Center, Memphis, TN 38163, USA
- Laboratory of Muscle Biology and Sarcopenia, Department of Physical Therapy, College of Health Professions, University of Tennessee Health Science Center, Memphis, TN 38163, USA
- Center for Muscle, Metabolism and Neuropathology, Division of Regenerative and Rehabilitation Sciences, College of Health Professions, University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | - Christopher R. Pitzer
- Department of Physiology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN 38163, USA
- Integrated Biomedical Sciences Graduate Program, College of Graduate Health Sciences, University of Tennessee Health Science Center, Memphis, TN 38163, USA
- Laboratory of Muscle Biology and Sarcopenia, Department of Physical Therapy, College of Health Professions, University of Tennessee Health Science Center, Memphis, TN 38163, USA
- Center for Muscle, Metabolism and Neuropathology, Division of Regenerative and Rehabilitation Sciences, College of Health Professions, University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | - Stephen E. Alway
- Department of Physiology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN 38163, USA
- Integrated Biomedical Sciences Graduate Program, College of Graduate Health Sciences, University of Tennessee Health Science Center, Memphis, TN 38163, USA
- Laboratory of Muscle Biology and Sarcopenia, Department of Physical Therapy, College of Health Professions, University of Tennessee Health Science Center, Memphis, TN 38163, USA
- Center for Muscle, Metabolism and Neuropathology, Division of Regenerative and Rehabilitation Sciences, College of Health Professions, University of Tennessee Health Science Center, Memphis, TN 38163, USA
- The Tennessee Institute of Regenerative Medicine, Memphis, TN 38163, USA
- Correspondence:
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21
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Abdelrahman Z, Wang X, Wang D, Zhang T, Zhang Y, Wang X, Chen Z. Identification of novel pathways and immune profiles related to sarcopenia. Front Med (Lausanne) 2023; 10:928285. [PMID: 37138756 PMCID: PMC10149827 DOI: 10.3389/fmed.2023.928285] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Accepted: 03/10/2023] [Indexed: 05/05/2023] Open
Abstract
Introduction Sarcopenia is a progressive deterioration of skeletal muscle mass strength and function. Methods To uncover the underlying cellular and biological mechanisms, we studied the association between sarcopenia's three stages and the patient's ethnicity, identified a gene regulatory network based on motif enrichment in the upregulated gene set of sarcopenia, and compared the immunological landscape among sarcopenia stages. Results We found that sarcopenia (S) was associated with GnRH, neurotrophin, Rap1, Ras, and p53 signaling pathways. Low muscle mass (LMM) patients showed activated pathways of VEGF signaling, B-cell receptor signaling, ErbB signaling, and T-cell receptor signaling. Low muscle mass and physical performance (LMM_LP) patients showed lower enrichment scores in B-cell receptor signaling, apoptosis, HIF-1 signaling, and the adaptive immune response pathways. Five common genes among DEGs and the elastic net regression model, TTC39DP, SLURP1, LCE1C, PTCD2P1, and OR7E109P, were expressed between S patients and healthy controls. SLURP1 and LCE1C showed the highest expression levels among sarcopenic Chinese descent than Caucasians and Afro-Caribbeans. Gene regulatory analysis of top upregulated genes in S patients yielded a top-scoring regulon containing GATA1, GATA2, and GATA3 as master regulators and nine predicted direct target genes. Two genes were associated with locomotion: POSTN and SLURP1. TTC39DP upregulation was associated with a better prognosis and stronger immune profile in S patients. The upregulation of SLURP1 and LCE1C was associated with a worse prognosis and weaker immune profile. Conclusion This study provides new insight into sarcopenia's cellular and immunological prospects and evaluates the age and sarcopenia-related modifications of skeletal muscle.
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Affiliation(s)
- Zeinab Abdelrahman
- Department of Neurobiology and Department of Rehabilitation Medicine, First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
- NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Science Center for Brain Research and Brain–Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, Zhejiang, China
- Department of Neurobiology and Department of Orthopedics, Zhejiang University School of Medicine, 2nd Affiliated Hospital, Hangzhou, Zhejiang, China
| | - Xiaosheng Wang
- Biomedical Informatics Research Lab, School of Basic Medicine and Clinical Pharmacy, China Pharmaceutical University, Nanjing, China
- Big Data Research Institute, China Pharmaceutical University, Nanjing, China
| | - Daming Wang
- Department of Neurobiology and Department of Rehabilitation Medicine, First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Tianfang Zhang
- Department of Neurobiology and Department of Rehabilitation Medicine, First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Yue Zhang
- Shenzhen Futian Hospital for Rheumatic Diseases, Shenzhen, China
| | - Xuhua Wang
- Department of Neurobiology and Department of Rehabilitation Medicine, First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
- NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Science Center for Brain Research and Brain–Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, Zhejiang, China
- Department of Neurobiology and Department of Orthopedics, Zhejiang University School of Medicine, 2nd Affiliated Hospital, Hangzhou, Zhejiang, China
- Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu, China
- Xuhua Wang
| | - Zuobing Chen
- Department of Neurobiology and Department of Rehabilitation Medicine, First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
- *Correspondence: Zuobing Chen
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22
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Mammalian Target of Rapamycin (mTOR) Signaling at the Crossroad of Muscle Fiber Fate in Sarcopenia. Int J Mol Sci 2022; 23:ijms232213823. [PMID: 36430301 PMCID: PMC9696247 DOI: 10.3390/ijms232213823] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 11/02/2022] [Accepted: 11/08/2022] [Indexed: 11/12/2022] Open
Abstract
The mammalian target of rapamycin (mTOR) is a major regulator of skeletal myocyte viability. The signaling pathways triggered by mTOR vary according to the type of endogenous and exogenous factors (e.g., redox balance, nutrient availability, physical activity) as well as organismal age. Here, we provide an overview of mTOR signaling in skeletal muscle, with a special focus on the role played by mTOR in the development of sarcopenia. Intervention strategies targeting mTOR in sarcopenia (e.g., supplementation of plant extracts, hormones, inorganic ions, calorie restriction, and exercise) have also been discussed.
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23
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Lim ZX, Goh J. Effects of blood flow restriction (BFR) with resistance exercise on musculoskeletal health in older adults: a narrative review. Eur Rev Aging Phys Act 2022; 19:15. [PMID: 35725379 PMCID: PMC9208167 DOI: 10.1186/s11556-022-00294-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Accepted: 05/27/2022] [Indexed: 11/22/2022] Open
Abstract
Background Aging leads to a number of structural and physiological deficits such as loss of muscle mass and strength. Strength training at ~ 70% of 1 repetition max (RM) is recommended to prevent age-related loss of muscle mass and strength. However, most older adults may not be able to perform 70% of 1RM or higher intensity. An alternative exercise training program combining low intensity resistance exercise with blood flow restriction (BFR) can result in similar acute and chronic benefits to skeletal muscles in older adults. Main body and short conclusion The potential mechanisms involved are discussed, and include reactive hyperaemia, metabolic stress, and hypoxia. Key issues and safety with the use of BFR in older adults, especially those with chronic conditions are also discussed. Although there has been no reported evidence to suggest that BFR elevates the risk of clinical complications any more than high intensity exercise, it is recommended for individuals to be medically cleared of any cardiovascular risks, prior to engaging in BFR exercise.
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Affiliation(s)
- Zi Xiang Lim
- Healthy Longevity Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore (NUS), Singapore, 117456, Singapore.,Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore (NUS), Singapore, 117456, Singapore.,Centre for Healthy Longevity, National University Health System (NUHS), Singapore, 117456, Singapore
| | - Jorming Goh
- Healthy Longevity Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore (NUS), Singapore, 117456, Singapore. .,Centre for Healthy Longevity, National University Health System (NUHS), Singapore, 117456, Singapore. .,Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore (NUS), Singapore, 117456, Singapore.
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24
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Nunes EA, Stokes T, McKendry J, Currier BS, Phillips SM. Disuse-induced skeletal muscle atrophy in disease and non-disease states in humans: mechanisms, prevention, and recovery strategies. Am J Physiol Cell Physiol 2022; 322:C1068-C1084. [PMID: 35476500 DOI: 10.1152/ajpcell.00425.2021] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Decreased skeletal muscle contractile activity (disuse) or unloading leads to muscle mass loss, also known as muscle atrophy. The balance between muscle protein synthesis (MPS) and muscle protein breakdown (MPB) is the primary determinant of skeletal muscle mass. A reduced mechanical load on skeletal muscle is one of the main external factors leading to muscle atrophy. However, endocrine and inflammatory factors can act synergistically in catabolic states, amplifying the atrophy process and accelerating its progression. Additionally, older individuals display aging-induced anabolic resistance, which can predispose this population to more pronounced effects when exposed to periods of reduced physical activity or mechanical unloading. Different cellular mechanisms contribute to the regulation of muscle protein balance during skeletal muscle atrophy. This review summarizes the effects of muscle disuse on muscle protein balance and the molecular mechanisms involved in muscle atrophy in the absence or presence of disease. Finally, a discussion of the current literature describing efficient strategies to prevent or improve the recovery from muscle atrophy is also presented.
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Affiliation(s)
- Everson A Nunes
- Exercise Metabolism Research Group, Department of Kinesiology, McMaster University, Hamilton, ON, Canada.,Laboratory of Investigation of Chronic Diseases, Department of Physiological Sciences, Federal University of Santa Catarina, Florianópolis, SC, Brazil
| | - Tanner Stokes
- Exercise Metabolism Research Group, Department of Kinesiology, McMaster University, Hamilton, ON, Canada
| | - James McKendry
- Exercise Metabolism Research Group, Department of Kinesiology, McMaster University, Hamilton, ON, Canada
| | - Brad S Currier
- Exercise Metabolism Research Group, Department of Kinesiology, McMaster University, Hamilton, ON, Canada
| | - Stuart M Phillips
- Exercise Metabolism Research Group, Department of Kinesiology, McMaster University, Hamilton, ON, Canada
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25
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Atallah N, Gaudichon C, Boulier A, Baniel A, Azzout-Marniche D, Khodorova N, Chaumontet C, Piedcoq J, Chapelais M, Calvez J. Moderate adiposity levels counteract protein metabolism modifications associated with aging in rats. Eur J Nutr 2022; 61:3189-3200. [PMID: 35435502 DOI: 10.1007/s00394-022-02881-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Accepted: 03/22/2022] [Indexed: 12/01/2022]
Abstract
PURPOSE Physiological parameters such as adiposity and age are likely to influence protein digestion and utilization. The aim of this study was to evaluate the combined effects of age and adiposity on casein protein and amino acid true digestibility and its postprandial utilization in rats. METHODS Four groups were included (n = 7/8): 2 months/normal adiposity, 2 months/high adiposity, 11 months/normal adiposity and 11 months/high adiposity. Rats were given a calibrated meal containing 15N-labeled casein (Ingredia, Arras, France) and were euthanized 6 h later. Digestive contents were collected to assess protein and amino acid digestibilities. 15N enrichments were measured in plasma and urine to determine total body deamination. Fractional protein synthesis rate (FSR) was determined in different organs using a flooding dose of 13C valine. RESULTS Nitrogen and amino acid true digestibility of casein was around 95-96% depending on the group and was increased by 1% in high adiposity rats (P = 0.04). Higher adiposity levels counteracted the increase in total body deamination (P = 0.03) that was associated with older age. Significant effects of age (P = 0.006) and adiposity (P = 0.002) were observed in the muscle FSR, with age decreasing it and adiposity increasing it. CONCLUSION This study revealed that a higher level of adiposity resulted in a slight increase in protein and individual amino acid true digestibility values and seemed to compensate for the metabolic postprandial protein alterations observed at older age.
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Affiliation(s)
- Nathalie Atallah
- Université Paris-Saclay, AgroParisTech, INRAE, UMR PNCA, 75005, Paris, France.,Ingredia S.A., 62033, Arras Cedex, France.,UMR Transfrontalière BioEcoAgro N°1158, University Lille, INRAE, University Liège, UPJV, YNCREA, University Artois, University Littoral Côte d'Opale, ICV - Institut Charles Viollette, 59000, Lille, France
| | - Claire Gaudichon
- Université Paris-Saclay, AgroParisTech, INRAE, UMR PNCA, 75005, Paris, France
| | | | | | | | - Nadezda Khodorova
- Université Paris-Saclay, AgroParisTech, INRAE, UMR PNCA, 75005, Paris, France
| | | | - Julien Piedcoq
- Université Paris-Saclay, AgroParisTech, INRAE, UMR PNCA, 75005, Paris, France
| | - Martin Chapelais
- Université Paris-Saclay, AgroParisTech, INRAE, UMR PNCA, 75005, Paris, France
| | - Juliane Calvez
- Université Paris-Saclay, AgroParisTech, INRAE, UMR PNCA, 75005, Paris, France.
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26
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Ebert SM, Rasmussen BB, Judge AR, Judge SM, Larsson L, Wek RC, Anthony TG, Marcotte GR, Miller MJ, Yorek MA, Vella A, Volpi E, Stern JI, Strub MD, Ryan Z, Talley JJ, Adams CM. Biology of Activating Transcription Factor 4 (ATF4) and Its Role in Skeletal Muscle Atrophy. J Nutr 2022; 152:926-938. [PMID: 34958390 PMCID: PMC8970988 DOI: 10.1093/jn/nxab440] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 12/17/2021] [Accepted: 12/23/2021] [Indexed: 12/30/2022] Open
Abstract
Activating transcription factor 4 (ATF4) is a multifunctional transcription regulatory protein in the basic leucine zipper superfamily. ATF4 can be expressed in most if not all mammalian cell types, and it can participate in a variety of cellular responses to specific environmental stresses, intracellular derangements, or growth factors. Because ATF4 is involved in a wide range of biological processes, its roles in human health and disease are not yet fully understood. Much of our current knowledge about ATF4 comes from investigations in cultured cell models, where ATF4 was originally characterized and where further investigations continue to provide new insights. ATF4 is also an increasingly prominent topic of in vivo investigations in fully differentiated mammalian cell types, where our current understanding of ATF4 is less complete. Here, we review some important high-level concepts and questions concerning the basic biology of ATF4. We then discuss current knowledge and emerging questions about the in vivo role of ATF4 in one fully differentiated cell type, mammalian skeletal muscle fibers.
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Affiliation(s)
- Scott M Ebert
- Department of Internal Medicine, Division of Endocrinology, Diabetes, Metabolism and Nutrition, Mayo Clinic, Rochester, MN, USA
- Emmyon, Inc., Rochester, MN, USA
| | - Blake B Rasmussen
- Emmyon, Inc., Rochester, MN, USA
- Department of Nutrition, Metabolism and Rehabilitation Sciences, University of Texas Medical Branch, Galveston, TX, USA
| | - Andrew R Judge
- Emmyon, Inc., Rochester, MN, USA
- Department of Physical Therapy, University of Florida, Gainesville, FL, USA
| | - Sarah M Judge
- Department of Physical Therapy, University of Florida, Gainesville, FL, USA
| | - Lars Larsson
- Department of Physiology and Pharmacology, Karolinska, Stockholm, Sweden
| | - Ronald C Wek
- Department of Biochemistry and Molecular Biology, Indiana University, Indianapolis, IN, USA
| | - Tracy G Anthony
- Department of Nutritional Sciences, Rutgers University, New Brunswick, NJ, USA
| | - George R Marcotte
- Department of Internal Medicine, Division of Endocrinology, Diabetes, Metabolism and Nutrition, Mayo Clinic, Rochester, MN, USA
- Department of Internal Medicine, University of Iowa, Iowa City, IA, USA
| | - Matthew J Miller
- Department of Internal Medicine, Division of Endocrinology, Diabetes, Metabolism and Nutrition, Mayo Clinic, Rochester, MN, USA
- Department of Internal Medicine, University of Iowa, Iowa City, IA, USA
| | - Mark A Yorek
- Department of Internal Medicine, University of Iowa, Iowa City, IA, USA
- Department of Internal Medicine, Iowa City VA Medical Center, Iowa City, IA, USA
| | - Adrian Vella
- Department of Internal Medicine, Division of Endocrinology, Diabetes, Metabolism and Nutrition, Mayo Clinic, Rochester, MN, USA
- Emmyon, Inc., Rochester, MN, USA
| | - Elena Volpi
- Department of Nutrition, Metabolism and Rehabilitation Sciences, University of Texas Medical Branch, Galveston, TX, USA
| | - Jennifer I Stern
- Department of Internal Medicine, Division of Endocrinology, Diabetes, Metabolism and Nutrition, Mayo Clinic, Rochester, MN, USA
| | - Matthew D Strub
- Department of Internal Medicine, Division of Endocrinology, Diabetes, Metabolism and Nutrition, Mayo Clinic, Rochester, MN, USA
| | - Zachary Ryan
- Department of Internal Medicine, Division of Endocrinology, Diabetes, Metabolism and Nutrition, Mayo Clinic, Rochester, MN, USA
| | | | - Christopher M Adams
- Department of Internal Medicine, Division of Endocrinology, Diabetes, Metabolism and Nutrition, Mayo Clinic, Rochester, MN, USA
- Emmyon, Inc., Rochester, MN, USA
- Department of Internal Medicine, Iowa City VA Medical Center, Iowa City, IA, USA
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27
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Strategies to Prevent Sarcopenia in the Aging Process: Role of Protein Intake and Exercise. Nutrients 2021; 14:nu14010052. [PMID: 35010928 PMCID: PMC8746908 DOI: 10.3390/nu14010052] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2021] [Revised: 12/19/2021] [Accepted: 12/21/2021] [Indexed: 12/24/2022] Open
Abstract
Sarcopenia is one of the main issues associated with the process of aging. Characterized by muscle mass loss, it is triggered by several conditions, including sedentary habits and negative net protein balance. According to World Health Organization, it is expected a 38% increase in older individuals by 2025. Therefore, it is noteworthy to establish recommendations to prevent sarcopenia and several events and comorbidities associated with this health issue condition. In this review, we discuss the role of these factors, prevention strategies, and recommendations, with a focus on protein intake and exercise.
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28
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Kojić F, Mandić D, Ilić V. Resistance training induces similar adaptations of upper and lower-body muscles between sexes. Sci Rep 2021; 11:23449. [PMID: 34873221 PMCID: PMC8648816 DOI: 10.1038/s41598-021-02867-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Accepted: 11/19/2021] [Indexed: 11/25/2022] Open
Abstract
The purpose of the study was to compare sex adaptations in hypertrophy, strength and contractile properties of upper and lower-body muscles induced by resistance training (RT). Eighteen RT untrained male (MG) and female (FG) students (aged 24.1 ± 1.7 years, height: 1.75 ± 0.08 m, weight: 70.4 ± 12.3 kg) undervent 7 weeks of biceps curl and squat training (2 days/week, 60–70% repetition maximum, 3–4 sets, 120 s rest intervals, reps until muscular failure). At baseline and final measurement, thickness and cross-section area, one-repetition maximum and tensiomyography parameters (contraction time − Tc and radial displacement − Dm) of elbow flexors (biceps brachii) and knee extensors (4 quadriceps muscles) were evaluated. Although MG tends to display greater absolute strength gains for upper- (p = 0.055) and lower-body (p = 0.098), for relative changes ANCOVA revealed no sex-specific differences for either of the tested variables. Significant hypertrophy was observed for all tested muscles, except for vastus intermedius in FG (p = 0.076). The Dm significantly decreased for biceps brachii (MG by 12%, p < 0.01 and FG by 13.1%, p < 0.01) and rectus femoris (MG by19.2%, p < 0.01 and FG by 12.3%, p < 0.05), while Tc values remain unchanged. These results indicate that initial morphological, functional and contractile alterations following RT are similar for males and females, and that there are no specific sex adaptations either for the upper- or lower-body muscles. The study was registered with ClinicalTrials.gov (NCT04845295).
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Affiliation(s)
- Filip Kojić
- Teacher Education Faculty, University of Belgrade, Kraljice Natalije 43, Belgrade, 11000, Serbia.
| | - Danimir Mandić
- Teacher Education Faculty, University of Belgrade, Kraljice Natalije 43, Belgrade, 11000, Serbia
| | - Vladimir Ilić
- Faculty of Sport and Physical Education, University of Belgrade, Belgrade, Serbia
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29
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Jayawardena TU, Kim SY, Jeon YJ. Sarcopenia; functional concerns, molecular mechanisms involved, and seafood as a nutritional intervention - review article. Crit Rev Food Sci Nutr 2021; 63:1983-2003. [PMID: 34459311 DOI: 10.1080/10408398.2021.1969889] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The fundamental basis for the human function is provided by skeletal muscle. Advancing age causes selective fiber atrophy, motor unit loss, and hybrid fiber formation resulting in hampered mass and strength, thus referred to as sarcopenia. Influence on the loss of independence of aged adults, contribute toward inclined healthcare costs conveys the injurious impact. The current understating of age-related skeletal muscle changes are addressed in this review, and further discusses mechanisms regulating protein turnover, although they do not completely define the process yet. Moreover, the reduced capacity of muscle regeneration due to impairment of satellite cell activation and proliferation with neuronal, immunological, hormonal factors were brought into the light of attention. Nevertheless, complete understating of sarcopenia requires disentangling it from disuse and disease. Nutritional intervention is considered a potentially preventable factor contributing to sarcopenia. Seafood is a crucial player in the fight against hunger and malnutrition, where it consists of macro and micronutrients. Hence, the review shed light on seafood as a nutritional intrusion in the treatment and prevention of sarcopenia. Understanding multiple factors will provide therapeutic targets in the prevention, treatment, and overcoming adverse effects of sarcopenia.
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Affiliation(s)
- Thilina U Jayawardena
- Department of Marine Life Sciences, Jeju National University, Jeju, Republic of Korea
| | - Seo-Young Kim
- Division of Practical Application, Honam National Institute of Biological Resources, Mokpo-si, Korea
| | - You-Jin Jeon
- Department of Marine Life Sciences, Jeju National University, Jeju, Republic of Korea.,Marine Science Institute, Jeju National University, Jeju, Jeju Self-Governing Province, Republic of Korea
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30
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Malnutrition in Older Adults-Recent Advances and Remaining Challenges. Nutrients 2021; 13:nu13082764. [PMID: 34444924 PMCID: PMC8399049 DOI: 10.3390/nu13082764] [Citation(s) in RCA: 194] [Impact Index Per Article: 64.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 08/04/2021] [Accepted: 08/10/2021] [Indexed: 12/12/2022] Open
Abstract
Malnutrition in older adults has been recognised as a challenging health concern associated with not only increased mortality and morbidity, but also with physical decline, which has wide ranging acute implications for activities of daily living and quality of life in general. Malnutrition is common and may also contribute to the development of the geriatric syndromes in older adults. Malnutrition in the old is reflected by either involuntary weight loss or low body mass index, but hidden deficiencies such as micronutrient deficiencies are more difficult to assess and therefore frequently overlooked in the community-dwelling old. In developed countries, the most cited cause of malnutrition is disease, as both acute and chronic disorders have the potential to result in or aggravate malnutrition. Therefore, as higher age is one risk factor for developing disease, older adults have the highest risk of being at nutritional risk or becoming malnourished. However, the aetiology of malnutrition is complex and multifactorial, and the development of malnutrition in the old is most likely also facilitated by ageing processes. This comprehensive narrative review summarizes current evidence on the prevalence and determinants of malnutrition in old adults spanning from age-related changes to disease-associated risk factors, and outlines remaining challenges in the understanding, identification as well as treatment of malnutrition, which in some cases may include targeted supplementation of macro- and/or micronutrients, when diet alone is not sufficient to meet age-specific requirements.
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31
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Impaired skeletal muscle hypertrophy signaling and amino acid deprivation response in Apoe knockout mice with an unhealthy lipoprotein distribution. Sci Rep 2021; 11:16423. [PMID: 34385572 PMCID: PMC8360952 DOI: 10.1038/s41598-021-96000-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Accepted: 07/27/2021] [Indexed: 11/16/2022] Open
Abstract
This study explores if unhealthy lipoprotein distribution (LPD) impairs the anabolic and amino acid sensing responses to whey-protein feeding. Thus, if impairment of such anabolic response to protein consumption is seen by the LPD this may negatively affect the skeletal muscle mass. Muscle protein synthesis (MPS) was measured by puromycin labeling in Apolipoprotein E knockout (Apoe KO), characterized by an unhealthy LPD, and wild type mice post-absorptive at 10 and 20 weeks, and post-prandial after whey-protein feeding at 20 weeks. Hypertrophy signaling and amino acid sensing mechanisms were studied and gut microbiome diversity explored. Surprisingly, whey-protein feeding did not affect MPS. p-mTOR and p-4E-BP1 was increased 2 h after whey-protein feeding in both genotypes, but with general lower levels in Apoe KO compared to wild type. At 20 weeks of age, Apoe KO had a greater mRNA-expression for SNAT2, CD98, ATF4 and GCN2 compared to wild type. These responses were not associated with gut microbiota compositional differences. Regardless of LPD status, MPS was similar in Apoe KO and wild type. Surprisingly, whey-protein did not stimulate MPS. However, Apoe KO had lower levels of hypertrophy signaling, was amino acid deprived, and had impaired amino acid sensing mechanisms.
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32
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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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33
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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: 27] [Impact Index Per Article: 9.0] [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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Paulussen KJM, McKenna CF, Beals JW, Wilund KR, Salvador AF, Burd NA. Anabolic Resistance of Muscle Protein Turnover Comes in Various Shapes and Sizes. Front Nutr 2021; 8:615849. [PMID: 34026802 PMCID: PMC8131552 DOI: 10.3389/fnut.2021.615849] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2020] [Accepted: 03/01/2021] [Indexed: 12/18/2022] Open
Abstract
Anabolic resistance is defined by a blunted stimulation of muscle protein synthesis rates (MPS) to common anabolic stimuli in skeletal muscle tissue such as dietary protein and exercise. Generally, MPS is the target of most exercise and feeding interventions as muscle protein breakdown rates seem to be less responsive to these stimuli. Ultimately, the blunted responsiveness of MPS to dietary protein and exercise underpins the loss of the amount and quality of skeletal muscle mass leading to decrements in physical performance in these populations. The increase of both habitual physical activity (including structured exercise that targets general fitness characteristics) and protein dense food ingestion are frontline strategies utilized to support muscle mass, performance, and health. In this paper, we discuss anabolic resistance as a common denominator underpinning muscle mass loss with aging, obesity, and other disease states. Namely, we discuss the fact that anabolic resistance exists as a dimmer switch, capable of varying from higher to lower levels of resistance, to the main anabolic stimuli of feeding and exercise depending on the population. Moreover, we review the evidence on whether increased physical activity and targeted exercise can be leveraged to restore the sensitivity of skeletal muscle tissue to dietary amino acids regardless of the population.
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Affiliation(s)
- Kevin J. M. Paulussen
- Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Urbana, IL, United States
| | - Colleen F. McKenna
- Division of Nutritional Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, United States
| | - Joseph W. Beals
- Center for Human Nutrition, Washington University School of Medicine, St. Louis, MO, United States
| | - Kenneth R. Wilund
- Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Urbana, IL, United States
- Division of Nutritional Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, United States
| | - Amadeo F. Salvador
- Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Urbana, IL, United States
| | - Nicholas A. Burd
- Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Urbana, IL, United States
- Division of Nutritional Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, United States
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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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Morgan PT, Harris DO, Marshall RN, Quinlan JI, Edwards SJ, Allen SL, Breen L. Protein Source and Quality for Skeletal Muscle Anabolism in Young and Older Adults: A Systematic Review and Meta-Analysis. J Nutr 2021; 151:1901-1920. [PMID: 33851213 PMCID: PMC8245874 DOI: 10.1093/jn/nxab055] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 01/07/2021] [Accepted: 02/11/2021] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND There is much debate regarding the source/quality of dietary proteins in supporting indices of skeletal muscle anabolism. OBJECTIVE We performed a systematic review and meta-analysis to determine the effect of protein source/quality on acute muscle protein synthesis (MPS) and changes in lean body mass (LBM) and strength, when combined with resistance exercise (RE). METHODS A systematic search of the literature was conducted to identify studies that compared the effects of ≥2 dose-matched, predominantly isolated protein sources of varying "quality." Three separate models were employed as follows: 1) protein feeding alone on MPS, 2) protein feeding combined with a bout of RE on MPS, and 3) protein feeding combined with longer-term resistance exercise training (RET) on LBM and strength. Further subgroup analyses were performed to compare the effects of protein source/quality between young and older adults. A total of 27 studies in young (18-35 y) and older (≥60 y) adults were included. RESULTS Analysis revealed an effect favoring higher-quality protein for postprandial MPS at rest [mean difference (MD): 0.014%/h; 95% CI: 0.006, 0.021; P < 0.001] and following RE (MD: 0.022%/h; 95% CI: 0.014, 0.030; P < 0.00001) in young (model 1: 0.016%/h; 95% CI: -0.004, 0.036; P = 0.12; model 2: 0.030%/h; 95% CI: 0.015, 0.045; P < 0.0001) and older (model 1: 0.012%/h; 95% CI: 0.006, 0.018; P < 0.001; model 2: 0.014%/h; 95% CI: 0.007, 0.021; P < 0.001) adults. However, although higher protein quality was associated with superior strength gains with RET [standardized mean difference (SMD): 0.24 kg; 95% CI: 0.02, 0.45; P = 0.03)], no effect was observed on changes to LBM (SMD: 0.05 kg; 95% CI: -0.16, 0.25; P = 0.65). CONCLUSIONS The current review suggests that protein quality may provide a small but significant impact on indices of muscle protein anabolism in young and older adults. However, further research is warranted to elucidate the importance of protein source/quality on musculoskeletal aging, particularly in situations of low protein intake.
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Affiliation(s)
- Paul T Morgan
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, UK
| | - Dane O Harris
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, UK
| | - Ryan N Marshall
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, UK
| | - Jonathan I Quinlan
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, UK,National Institute for Health Research, Birmingham Biomedical Research Centre at University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
| | - Sophie J Edwards
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, UK
| | - Sophie L Allen
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, UK
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Lu Y, Niti M, Yap KB, Tan CTY, Nyunt MSZ, Feng L, Tan BY, Chan G, Khoo SA, Chan SM, Yap P, Larbi A, Ng TP. Effects of multi-domain lifestyle interventions on sarcopenia measures and blood biomarkers: secondary analysis of a randomized controlled trial of community-dwelling pre-frail and frail older adults. Aging (Albany NY) 2021; 13:9330-9347. [PMID: 33882026 PMCID: PMC8064206 DOI: 10.18632/aging.202705] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Accepted: 02/09/2021] [Indexed: 01/06/2023]
Abstract
Few studies have comprehensively described changes in blood biomarkers of the physiological responses underlying sarcopenia reduction associated with lifestyle interventions. In this study, we performed secondary analyses of data in a randomized controlled trial of multi-domain lifestyle interventions (6-month duration physical exercise, nutritional enrichment, cognitive training, combination and standard care control) among 246 community-dwelling pre-frail and frail elderly, aged ≥65 years, with and without sarcopenia. Appendicular lean mass (ALM), lower limb strength, gait speed, and blood levels of markers of muscle metabolism, inflammation, anti-oxidation, anabolic hormone regulation, insulin signaling, tissue oxygenation were measured at baseline, 3-month and 6-month post-intervention. Multi-domain interventions were associated with significant (p < 0.001) reduction of sarcopenia at 3-month and 6-month post-intervention, improved gait speed, enhanced lower limb strength, and were equally evident among sarcopenic participants who were slower at baseline than non-sarcopenic participants. Active intervention was associated with significantly reduced inflammation levels. Sarcopenia status and reduction were associated with blood biomarkers related to muscle metabolism, steroid hormone regulation, insulin-leptin signaling, and tissue oxygenation. Physical, nutritional and cognitive intervention was associated with measures of sarcopenia reduction, together with changes in circulating biomarkers of anabolic and catabolic metabolism underlying sarcopenia.
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Affiliation(s)
- Yanxia Lu
- Department of Medical Psychology and Ethics, School of Basic Medical Sciences, Shandong University, Jinan 250012, China
| | - Mathew Niti
- Performance and Technology Assessment Department, Ministry of Health, Singapore
| | - Keng Bee Yap
- Geriatric Medicine and Palliative Medicine Department, Ng Teng Fong General Hospital, Singapore
| | - Crystal Tze Ying Tan
- Biology of Ageing Laboratory, Singapore Immunology Network (SIgN), Agency for Science Technology and Research (A*STAR), Immunos Building, Biopolis, Singapore
| | - Ma Shwe Zin Nyunt
- Gerontology Research Programme, Department of Psychological Medicine, National University Health System, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Liang Feng
- Gerontology Research Programme, Department of Psychological Medicine, National University Health System, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Boon Yeow Tan
- Medical Services Department, St Luke's Hospital, Singapore
| | - Gribson Chan
- Rehabilitation Services Division, St Luke's Hospital, Singapore
| | - Sue Anne Khoo
- Psychological Medicine Department, Khoo Teck Puat Hospital, Singapore
| | - Sue Mei Chan
- Nutrition and Dietetics Department, Khoo Teck Puat Hospital, Singapore
| | - Philip Yap
- Geriatric Medicine Department, Khoo Teck Puat Hospital, Singapore
| | - Anis Larbi
- Biology of Ageing Laboratory, Singapore Immunology Network (SIgN), Agency for Science Technology and Research (A*STAR), Immunos Building, Biopolis, Singapore.,Geriatrics Division, Department of Medicine, Research Center on Aging, University of Sherbrooke, Sherbrooke, Quebec, Canada
| | - Tze Pin Ng
- Gerontology Research Programme, Department of Psychological Medicine, National University Health System, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
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Picca A, Calvani R, Sirago G, Coelho-Junior HJ, Marzetti E. Molecular routes to sarcopenia and biomarker development: per aspera ad astra. Curr Opin Pharmacol 2021; 57:140-147. [PMID: 33721617 DOI: 10.1016/j.coph.2021.02.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 12/31/2020] [Accepted: 02/09/2021] [Indexed: 12/17/2022]
Abstract
Sarcopenia, the age-related decline in muscle mass and strength/function, is a prototypical geroscience condition. The dissection of muscle-specific molecular pathways through analyses of tissue biopsies has provided valuable insights into the pathophysiology of sarcopenia. However, such an approach is unsuitable for capturing the dynamic nature of the condition. Furthermore, the muscle sampling procedure may be perceived as burdensome especially by multimorbid, frail older adults. To overcome these limitations, sophisticated statistical methods have been devised for the simultaneous analysis of circulating factors related to the multiple domains of sarcopenia. This approach has shown potential for achieving a more comprehensive appraisal of the condition, unveiling new therapeutic targets, and identifying meaningful biomarkers. Here, we discuss the main pathogenetic pathways of sarcopenia, with a focus on mediators that are currently in the spotlight as biomarkers and potential treatment targets.
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Affiliation(s)
- Anna Picca
- Fondazione Policlinico Universitario "Agostino Gemelli" IRCCS, Rome, Italy; Aging Research Center, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet and Stockholm University, Stockholm, Sweden
| | - Riccardo Calvani
- Fondazione Policlinico Universitario "Agostino Gemelli" IRCCS, Rome, Italy; Aging Research Center, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet and Stockholm University, Stockholm, Sweden
| | - Giuseppe Sirago
- Department of Biomedical Sciences DBS, Università degli Studi di Padova, Padua, Italy
| | - Hélio José Coelho-Junior
- Università Cattolica del Sacro Cuore, Institute of Internal Medicine and Geriatrics, Rome, Italy
| | - Emanuele Marzetti
- Fondazione Policlinico Universitario "Agostino Gemelli" IRCCS, Rome, Italy; Università Cattolica del Sacro Cuore, Institute of Internal Medicine and Geriatrics, Rome, Italy.
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Ruocco C, Segala A, Valerio A, Nisoli E. Essential amino acid formulations to prevent mitochondrial dysfunction and oxidative stress. Curr Opin Clin Nutr Metab Care 2021; 24:88-95. [PMID: 33060458 DOI: 10.1097/mco.0000000000000704] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
PURPOSE OF REVIEW Both restriction and supplementation of specific amino acids or branched-chain amino acids (BCAAs) are described to improve metabolic homeostasis, energy balance, and health span. This review will discuss the recent findings of the role of amino acid supplements in the regulation of mitochondrial health. RECENT FINDINGS A mixture of essential amino acids (EAAs), BCAA enriched mixture, was found to extend healthy life span in elderly mice and prevent multiple diseases associated with an energy deficit, similarly to caloric restriction or fasting-mimicking diets. A growing body of evidence highlights mitochondria as the central target of this supplement: it promotes mitochondrial biogenesis and the activation of antioxidant defence systems in different physiological (e.g., exercise or ageing) or pathological conditions (e.g., sarcopenia, muscular dystrophy, liver steatosis, or impaired cognition). Based on these results, new formulas have been created enriched with Krebs cycle substrates, behaving more efficiently than BCAA enriched mixture. SUMMARY EAA-BCAA balanced supplements might be valuable not only for healthy individuals undergoing to energy deficit (e.g., athletes) during strenuous exercise or training but also against diseases characterized by a dysregulated catabolic state or mitochondrial dysfunction, such as age-related disorders. The associated mechanistic processes should be identified as potential pharmacological targets.
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Affiliation(s)
- Chiara Ruocco
- Department of Biomedical Technology and Translational Medicine, Center for Study and Research on Obesity, University of Milan, Milan
| | - Agnese Segala
- Department of Molecular and Translational Medicine, Brescia University, Brescia, Italy
| | - Alessandra Valerio
- Department of Molecular and Translational Medicine, Brescia University, Brescia, Italy
| | - Enzo Nisoli
- Department of Biomedical Technology and Translational Medicine, Center for Study and Research on Obesity, University of Milan, Milan
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Hirsch KR, Church DD, Kim IY, Park S, Wolfe RR, Ferrando AA. Comparison of basal whole-body protein kinetics and muscle protein synthesis between young and older adults. Physiol Rep 2020; 8:e14633. [PMID: 33278070 PMCID: PMC7718838 DOI: 10.14814/phy2.14633] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Revised: 10/08/2020] [Accepted: 10/09/2020] [Indexed: 12/18/2022] Open
Abstract
Significant research has been dedicated to counteracting age-related muscle loss, but underlying mechanisms have not been clearly established. Previous research examining differences in basal protein kinetics between young and older individuals has been limited by a lack of evaluation of protein breakdown and net balance. The aim of this study was to more comprehensively examine differences in basal protein kinetics between younger and older males and females. Basal whole-body protein kinetics and muscle fractional synthetic rate (FSR) from 91 younger (18-38 years; 52% female) and 66 older (51-81 years; 53% female) healthy adults were determined using stable isotope tracer techniques (L-[ring-2 H5 ]phenylalanine and L-[ring-2 H2 ]tyrosine). There were no group × sex interaction effects (p > .05). Older individuals had greater whole-body protein synthesis (mean difference old-young (Δ) ± SE: 28.54 ± 8.15 mg/kg LBM/hr; p = .001) and breakdown (Δ: 15.44 ± 7.33 mg/kgLBM/hr; p = .038), but a less negative net balance (Mean ± SD: Young: -31.22 ± 7.42 mg/kg LBM/hr; Old: -18.11 ± 21.60 mg/kg LBM/hr; p < .001) compared to young individuals. Basal FSR was not significantly different between young and older (Δ: 0.007 ± 0.003%/hr; p = .052). Across the age range, females had greater whole-body protein turnover (PSΔ: 19.10 ± 7.00 mg/kgLBM/hr; PBΔ: 19.22 ± 6.31 mg/kgLBM/hr; p < .01) compared to males. Results demonstrate a difference in basal whole-body protein kinetics between young and older adults, with older adults having a higher protein turnover rate and a less negative net balance. Across the age range, females were also found to have a higher turnover rate compared to males. Differences may represent a shift in older physiology toward mechanisms that increase the efficiency of amino acid reutilization, especially in women.
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Affiliation(s)
- Katie R Hirsch
- Department of Geriatrics, Donald W. Reynolds Institute on Aging, Center for Translational Research in Aging and Longevity, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - David D Church
- Department of Geriatrics, Donald W. Reynolds Institute on Aging, Center for Translational Research in Aging and Longevity, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Il-Young Kim
- Department of Molecular Medicine, Lee Gil Ya Cancer and Diabetes Institute, College of Medicine, Gachon University, Incheon, South Korea
| | - Sanghee Park
- Department of Molecular Medicine, Lee Gil Ya Cancer and Diabetes Institute, College of Medicine, Gachon University, Incheon, South Korea
| | - Robert R Wolfe
- Department of Geriatrics, Donald W. Reynolds Institute on Aging, Center for Translational Research in Aging and Longevity, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Arny A Ferrando
- Department of Geriatrics, Donald W. Reynolds Institute on Aging, Center for Translational Research in Aging and Longevity, University of Arkansas for Medical Sciences, Little Rock, AR, USA
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Welch C, Greig C, Masud T, Wilson D, Jackson TA. COVID-19 and Acute Sarcopenia. Aging Dis 2020; 11:1345-1351. [PMID: 33269092 PMCID: PMC7673845 DOI: 10.14336/ad.2020.1014] [Citation(s) in RCA: 91] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Accepted: 10/14/2020] [Indexed: 12/15/2022] Open
Abstract
The COVID-19 pandemic has had a devastating global impact, with older adults being most at risk of death from the disease. However, acute sarcopenia occurs in survivors of COVID-19; older adults and the most critically unwell patients are the most at risk. Acute sarcopenia is an under-recognised condition of acute muscle insufficiency, defined by declines in muscle function and/or quantity within six months, usually following a stressor event. This commentary reviews definition and mechanisms of acute sarcopenia in COVID-19 and suggests recommendations for research and clinical practice. Research should now focus on the longer-term consequences of acute sarcopenia in patients who have suffered from COVID-19. At the same time, clinicians need to be increasingly aware of the condition, and measurements of muscle strength, quantity, and physical performance should be embedded into clinical practice. Clinicians should consider the risks of acute sarcopenia when weighing up the risks and benefits of treatment (e.g. dexamethasone), and instigate multidisciplinary treatment including dietetics input.
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Affiliation(s)
- Carly Welch
- Institute of Inflammation and Ageing, College of Medical and Dental Sciences, University of Birmingham, Birmingham, B15 2TT, UK.
- MRC-Versus Arthritis Centre for Musculoskeletal Ageing Research, University of Birmingham and University of Nottingham, UK.
- University Hospitals Birmingham NHS Trust, Birmingham, B15 2GW, UK.
| | - Carolyn Greig
- MRC-Versus Arthritis Centre for Musculoskeletal Ageing Research, University of Birmingham and University of Nottingham, UK.
- School of Sport, Exercise, and Rehabilitation Sciences, University of Birmingham, Birmingham, B15 2TT, UK.
- Birmingham Biomedical Research Centre, University of Birmingham and University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK.
| | - Tahir Masud
- MRC-Versus Arthritis Centre for Musculoskeletal Ageing Research, University of Birmingham and University of Nottingham, UK.
- University of Nottingham, Nottingham, UK.
- Nottingham University Hospitals NHS Trust, Nottingham, UK.
| | - Daisy Wilson
- Institute of Inflammation and Ageing, College of Medical and Dental Sciences, University of Birmingham, Birmingham, B15 2TT, UK.
- University Hospitals Birmingham NHS Trust, Birmingham, B15 2GW, UK.
| | - Thomas A Jackson
- Institute of Inflammation and Ageing, College of Medical and Dental Sciences, University of Birmingham, Birmingham, B15 2TT, UK.
- MRC-Versus Arthritis Centre for Musculoskeletal Ageing Research, University of Birmingham and University of Nottingham, UK.
- University Hospitals Birmingham NHS Trust, Birmingham, B15 2GW, UK.
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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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The neuromuscular junction is a focal point of mTORC1 signaling in sarcopenia. Nat Commun 2020; 11:4510. [PMID: 32908143 PMCID: PMC7481251 DOI: 10.1038/s41467-020-18140-1] [Citation(s) in RCA: 81] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Accepted: 08/05/2020] [Indexed: 12/21/2022] Open
Abstract
With human median lifespan extending into the 80s in many developed countries, the societal burden of age-related muscle loss (sarcopenia) is increasing. mTORC1 promotes skeletal muscle hypertrophy, but also drives organismal aging. Here, we address the question of whether mTORC1 activation or suppression is beneficial for skeletal muscle aging. We demonstrate that chronic mTORC1 inhibition with rapamycin is overwhelmingly, but not entirely, positive for aging mouse skeletal muscle, while genetic, muscle fiber-specific activation of mTORC1 is sufficient to induce molecular signatures of sarcopenia. Through integration of comprehensive physiological and extensive gene expression profiling in young and old mice, and following genetic activation or pharmacological inhibition of mTORC1, we establish the phenotypically-backed, mTORC1-focused, multi-muscle gene expression atlas, SarcoAtlas (https://sarcoatlas.scicore.unibas.ch/), as a user-friendly gene discovery tool. We uncover inter-muscle divergence in the primary drivers of sarcopenia and identify the neuromuscular junction as a focal point of mTORC1-driven muscle aging.
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Castets P, Ham DJ, Rüegg MA. The TOR Pathway at the Neuromuscular Junction: More Than a Metabolic Player? Front Mol Neurosci 2020; 13:162. [PMID: 32982690 PMCID: PMC7485269 DOI: 10.3389/fnmol.2020.00162] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Accepted: 08/05/2020] [Indexed: 12/18/2022] Open
Abstract
The neuromuscular junction (NMJ) is the chemical synapse connecting motor neurons and skeletal muscle fibers. NMJs allow all voluntary movements, and ensure vital functions like breathing. Changes in the structure and function of NMJs are hallmarks of numerous pathological conditions that affect muscle function including sarcopenia, the age-related loss of muscle mass and function. However, the molecular mechanisms leading to the morphological and functional perturbations in the pre- and post-synaptic compartments of the NMJ remain poorly understood. Here, we discuss the role of the metabolic pathway associated to the kinase TOR (Target of Rapamycin) in the development, maintenance and alterations of the NMJ. This is of particular interest as the TOR pathway has been implicated in aging, but its role at the NMJ is still ill-defined. We highlight the respective functions of the two TOR-associated complexes, TORC1 and TORC2, and discuss the role of localized protein synthesis and autophagy regulation in motor neuron terminals and sub-synaptic regions of muscle fibers and their possible effects on NMJ maintenance.
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Affiliation(s)
- Perrine Castets
- Department of Cell Physiology and Metabolism, Faculty of Medicine, University of Geneva, Geneva, Switzerland
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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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Zacharewicz E, Kalanon M, Murphy RM, Russell AP, Lamon S. MicroRNA-99b-5p downregulates protein synthesis in human primary myotubes. Am J Physiol Cell Physiol 2020; 319:C432-C440. [PMID: 32608991 DOI: 10.1152/ajpcell.00172.2020] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
microRNAs (miRNAs) are important regulators of cellular homeostasis and exert their effect by directly controlling protein expression. We have previously reported an age-dependent negative association between microRNA-99b (miR-99b-5p) expression and muscle protein synthesis in human muscle in vivo. Here we investigated the role of miR-99b-5p as a potential negative regulator of protein synthesis via inhibition of mammalian target for rapamycin (MTOR) signaling in human primary myocytes. Overexpressing miR-99b-5p in human primary myotubes from young and old subjects significantly decreased protein synthesis with no effect of donor age. A binding interaction between miR-99b-5p and its putative binding site within the MTOR 3'-untranslated region (UTR) was confirmed in C2C12 myoblasts. The observed decline in protein synthesis was, however, not associated with a suppression of the MTOR protein but of its regulatory associated protein of mTOR complex 1 (RPTOR). These results demonstrate that modulating the expression levels of a miRNA can regulate protein synthesis in human muscle cells and provide a potential mechanism for muscle wasting in vivo.
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Affiliation(s)
- Evelyn Zacharewicz
- Institute for Physical Activity and Nutrition, School of Exercise and Nutrition Sciences, Deakin University, Geelong, Victoria, Australia
| | - Ming Kalanon
- Institute for Physical Activity and Nutrition, School of Exercise and Nutrition Sciences, Deakin University, Geelong, Victoria, Australia
| | - Robyn M Murphy
- Department of Physiology, Anatomy and Microbiology, School of Life Sciences, La Trobe University, Melbourne, Victoria, Australia
| | - Aaron P Russell
- Institute for Physical Activity and Nutrition, School of Exercise and Nutrition Sciences, Deakin University, Geelong, Victoria, Australia
| | - Séverine Lamon
- Institute for Physical Activity and Nutrition, School of Exercise and Nutrition Sciences, Deakin University, Geelong, Victoria, Australia
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Mankhong S, Kim S, Moon S, Kwak HB, Park DH, Kang JH. Experimental Models of Sarcopenia: Bridging Molecular Mechanism and Therapeutic Strategy. Cells 2020; 9:E1385. [PMID: 32498474 PMCID: PMC7348939 DOI: 10.3390/cells9061385] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 05/27/2020] [Accepted: 05/27/2020] [Indexed: 12/15/2022] Open
Abstract
Sarcopenia has been defined as a progressive decline of skeletal muscle mass, strength, and functions in elderly people. It is accompanied by physical frailty, functional disability, falls, hospitalization, and mortality, and is becoming a major geriatric disorder owing to the increasing life expectancy and growing older population worldwide. Experimental models are critical to understand the pathophysiology of sarcopenia and develop therapeutic strategies. Although its etiologies remain to be further elucidated, several mechanisms of sarcopenia have been identified, including cellular senescence, proteostasis imbalance, oxidative stress, and "inflammaging." In this article, we address three main aspects. First, we describe the fundamental aging mechanisms. Next, we discuss both in vitro and in vivo experimental models based on molecular mechanisms that have the potential to elucidate the biochemical processes integral to sarcopenia. The use of appropriate models to reflect sarcopenia and/or its underlying pathways will enable researchers to understand sarcopenia and develop novel therapeutic strategies for sarcopenia. Lastly, we discuss the possible molecular targets and the current status of drug candidates for sarcopenia treatment. In conclusion, the development of experimental models for sarcopenia is essential to discover molecular targets that are valuable as biochemical biomarkers and/or therapeutic targets for sarcopenia.
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Affiliation(s)
- Sakulrat Mankhong
- Department of Pharmacology, Hypoxia-related Disease Research Center, College of Medicine, Inha University, Incheon 22212, Korea; (S.M.); (S.K.); (S.M.)
| | - Sujin Kim
- Department of Pharmacology, Hypoxia-related Disease Research Center, College of Medicine, Inha University, Incheon 22212, Korea; (S.M.); (S.K.); (S.M.)
- Department of Kinesiology, Inha University, Incheon 22212, Korea; (H.-B.K.); (D.-H.P.)
- Institute of Sports & Arts Convergence (ISAC), Inha University, Incheon 22212, Korea
| | - Sohee Moon
- Department of Pharmacology, Hypoxia-related Disease Research Center, College of Medicine, Inha University, Incheon 22212, Korea; (S.M.); (S.K.); (S.M.)
| | - Hyo-Bum Kwak
- Department of Kinesiology, Inha University, Incheon 22212, Korea; (H.-B.K.); (D.-H.P.)
- Institute of Sports & Arts Convergence (ISAC), Inha University, Incheon 22212, Korea
| | - Dong-Ho Park
- Department of Kinesiology, Inha University, Incheon 22212, Korea; (H.-B.K.); (D.-H.P.)
- Institute of Sports & Arts Convergence (ISAC), Inha University, Incheon 22212, Korea
| | - Ju-Hee Kang
- Department of Pharmacology, Hypoxia-related Disease Research Center, College of Medicine, Inha University, Incheon 22212, Korea; (S.M.); (S.K.); (S.M.)
- Institute of Sports & Arts Convergence (ISAC), Inha University, Incheon 22212, Korea
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Hentilä J, Hulmi JJ, Laakkonen EK, Ahtiainen JP, Suominen H, Korhonen MT. Sprint and Strength Training Modulates Autophagy and Proteostasis in Aging Sprinters. Med Sci Sports Exerc 2020; 52:1948-1959. [PMID: 32205677 DOI: 10.1249/mss.0000000000002340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
PURPOSE Exercise and aging may modulate muscle protein homeostasis and autophagy, but few studies examine highly trained middle-age or older individuals. This study elucidated the effects of a new long-term training stimulus on markers of muscle autophagy and unfolded protein response (UPR) and on sprint running performance in masters sprinters. METHODS Thirty-two male competitive sprinters (age 40-76 yr) were randomly divided into experimental (EX) and control (CTRL) groups. The EX training program was a combination of heavy and explosive strength and sprint exercises aimed at improving sprint performance. Fifteen and thirteen participants completed the 20-wk intervention period in EX and CTRL, respectively. The latter were told to continue their routine exercises. Key protein markers were analyzed by Western blotting from vastus lateralis (VL) muscle biopsies. The muscle thickness of VL was analyzed by ultrasonography and sprint performance by a 60-m running test. RESULTS EX induced improvement in 60-m sprint performance when compared with controls (time-group, P = 0.003) without changes in VL muscle thickness. Content of lipidated microtubule-associated protein 1A/1B-light chain 3 (LC3-II) increased in EX (P = 0.022), suggesting increased autophagosome content. In addition, an autophagosome clearance marker sequestosome 1 (p62) decreased in EX (P = 0.006). Markers of UPR selectively modulated with decreases (e.g., ATF4, P = 0.003) and increases (e.g., EIF2α, P = 0.019) observed in EX. CONCLUSIONS These findings suggest that a new intensive training stimulus that combines strength training with sprint training may increase muscle autophagosome content in a basal state without any evidence of impaired autophagosome clearance in masters sprinters. Simultaneously, the combined training may have a selective effect on the content of UPR signaling components.
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Affiliation(s)
- Jaakko Hentilä
- Faculty of Sport and Health Sciences, Neuromuscular Research Center, University of Jyväskylä, Jyväskylä, FINLAND
| | | | - Eija K Laakkonen
- Faculty of Sport and Health Sciences, Gerontology Research Center, University of Jyväskylä, Jyväskylä, FINLAND
| | - Juha P Ahtiainen
- Faculty of Sport and Health Sciences, Neuromuscular Research Center, University of Jyväskylä, Jyväskylä, FINLAND
| | - Harri Suominen
- Faculty of Sport and Health Sciences, University of Jyväskylä, Jyväskylä, FINLAND
| | - Marko T Korhonen
- Faculty of Sport and Health Sciences, Gerontology Research Center, University of Jyväskylä, Jyväskylä, FINLAND
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Yakabe M, Hosoi T, Akishita M, Ogawa S. Updated concept of sarcopenia based on muscle-bone relationship. J Bone Miner Metab 2020; 38:7-13. [PMID: 31583540 DOI: 10.1007/s00774-019-01048-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/11/2019] [Accepted: 09/08/2019] [Indexed: 02/07/2023]
Abstract
Sarcopenia is an age-related loss of skeletal muscle mass and strength. It has been widely recognized that low muscle mass was essential in the diagnosis of sarcopenia, whereas recent studies have emphasized the importance of muscle strength. In practice, muscle quality as well as muscle mass might determine the strength and physical performance. A new diagnostic algorithm of sarcopenia has recently been established, in which low muscle strength is a key characteristic factor for the diagnosis of sarcopenia. Although many factors are supposed to be involved in the pathology and development of sarcopenia, precise mechanisms remain to be elucidated. Recent studies have also focused on the crosstalk between muscles and bones, including functional involvement of myokines and osteokines.
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Affiliation(s)
- Mitsutaka Yakabe
- Department of Geriatric Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan
| | - Tatsuya Hosoi
- Department of Geriatric Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan
| | - Masahiro Akishita
- Department of Geriatric Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan
| | - Sumito Ogawa
- Department of Geriatric Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan.
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50
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Tan KT, Ang STJ, Tsai SY. Sarcopenia: Tilting the Balance of Protein Homeostasis. Proteomics 2019; 20:e1800411. [PMID: 31722440 DOI: 10.1002/pmic.201800411] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Revised: 11/04/2019] [Indexed: 12/14/2022]
Abstract
Sarcopenia, defined as age-associated decline of muscle mass and function, is a risk factor for mortality and disability, and comorbid with several chronic diseases such as type II diabetes and cardiovascular diseases. Clinical trials showed that nutritional supplements had positive effects on muscle mass, but not on muscle function and strength, demonstrating our limited understanding of the molecular events involved in the ageing muscle. Protein homeostasis, the equilibrium between protein synthesis and degradation, is proposed as the major mechanism underlying the development of sarcopenia. As the key central regulator of protein homeostasis, the mammalian target of rapamycin (mTOR) is proposed to be essential for muscle hypertrophy. Paradoxically, sustained activation of mTOR complex 1 (mTORC1) is associated with a loss of sensitivity to extracellular signaling in the elderly. It is not understood why sustained mTORC1 activity, which should induce muscle hypertrophy, instead results in muscle atrophy. Here, recent findings on the implications of disrupting protein homeostasis on muscle physiology and sarcopenia development in the context of mTOR/protein kinase B (AKT) signaling are reviewed. Understanding the role of these molecular mechanisms during the ageing process will contribute towards the development of targeted therapies that will improve protein metabolism and reduce sarcopenia.
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Affiliation(s)
- Kuan Ting Tan
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, 2 Medical Drive, MD9 Admin Office, Singapore, 117597, Singapore
| | - Seok-Ting Jamie Ang
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, 2 Medical Drive, MD9 Admin Office, Singapore, 117597, Singapore
| | - Shih-Yin Tsai
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, 2 Medical Drive, MD9 Admin Office, Singapore, 117597, Singapore
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