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Ryan PJ, Uranga S, Stanelle ST, Lewis MH, O'Reilly CL, Cardin JM, Deaver JW, Morton AB, Fluckey JD. The autophagy inhibitor NSC185058 suppresses mTORC1-mediated protein anabolism in cultured skeletal muscle. Sci Rep 2024; 14:8094. [PMID: 38582781 PMCID: PMC10998866 DOI: 10.1038/s41598-024-58716-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2023] [Accepted: 04/02/2024] [Indexed: 04/08/2024] Open
Abstract
The mammalian target of rapamycin (mTOR), and specifically the mTOR complex 1 (mTORC1) is the central regulator of anabolism in skeletal muscle. Among the many functions of this kinase complex is the inhibition of the catabolic process of autophagy; however, less work has been done in investigating the role of autophagy in regulating mTORC1 signaling. Using an in vitro model to better understand the pathways involved, we activated mTORC1 by several different means (growth factors, leucine supplementation, or muscle contraction), alone or with the autophagy inhibitor NSC185058. We found that inhibiting autophagy with NSC185058 suppresses mTORC1 activity, preventing any increase in cellular protein anabolism. These decrements were the direct result of action on the mTORC1 kinase, which we demonstrate, for the first time, cannot function when autophagy is inhibited by NSC185058. Our results indicate that, far from being a matter of unidirectional action, the relationship between mTORC1 and the autophagic cascade is more nuanced, with autophagy serving as an mTORC1 input, and mTORC1 inhibition of autophagy as a form of homeostatic feedback to regulate anabolic signaling. Future studies of cellular metabolism will have to consider this fundamental intertwining of protein anabolism and catabolism, and how it ultimately serves to regulate muscle proteostasis.
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Affiliation(s)
- Patrick J Ryan
- Muscle Biology Laboratory, Department of Kinesiology and Sport Management, Texas A&M University, Gilchrist Building, 2929 Research Parkway, College Station, TX, 77843-4243, USA
| | - Selina Uranga
- Muscle Biology Laboratory, Department of Kinesiology and Sport Management, Texas A&M University, Gilchrist Building, 2929 Research Parkway, College Station, TX, 77843-4243, USA
| | - Sean T Stanelle
- Muscle Biology Laboratory, Department of Kinesiology and Sport Management, Texas A&M University, Gilchrist Building, 2929 Research Parkway, College Station, TX, 77843-4243, USA
| | - Megan H Lewis
- Muscle Biology Laboratory, Department of Kinesiology and Sport Management, Texas A&M University, Gilchrist Building, 2929 Research Parkway, College Station, TX, 77843-4243, USA
| | - Colleen L O'Reilly
- Muscle Biology Laboratory, Department of Kinesiology and Sport Management, Texas A&M University, Gilchrist Building, 2929 Research Parkway, College Station, TX, 77843-4243, USA
| | - Jessica M Cardin
- Muscle Biology Laboratory, Department of Kinesiology and Sport Management, Texas A&M University, Gilchrist Building, 2929 Research Parkway, College Station, TX, 77843-4243, USA
| | - J William Deaver
- Muscle Biology Laboratory, Department of Kinesiology and Sport Management, Texas A&M University, Gilchrist Building, 2929 Research Parkway, College Station, TX, 77843-4243, USA
| | - Aaron B Morton
- Soft Tissue Regeneration and Applied Biomaterials Laboratory, Texas A&M University, Gilchrist Building, 2929 Research Parkway, College Station, TX, 77843-4243, USA
| | - James D Fluckey
- Muscle Biology Laboratory, Department of Kinesiology and Sport Management, Texas A&M University, Gilchrist Building, 2929 Research Parkway, College Station, TX, 77843-4243, USA.
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2
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Hesketh SJ. Advancing cancer cachexia diagnosis with -omics technology and exercise as molecular medicine. SPORTS MEDICINE AND HEALTH SCIENCE 2024; 6:1-15. [PMID: 38463663 PMCID: PMC10918365 DOI: 10.1016/j.smhs.2024.01.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Revised: 01/15/2024] [Accepted: 01/20/2024] [Indexed: 03/12/2024] Open
Abstract
Muscle atrophy exacerbates disease outcomes and increases mortality, whereas the preservation of skeletal muscle mass and function play pivotal roles in ensuring long-term health and overall quality-of-life. Muscle atrophy represents a significant clinical challenge, involving the continued loss of muscle mass and strength, which frequently accompany the development of numerous types of cancer. Cancer cachexia is a highly prevalent multifactorial syndrome, and although cachexia is one of the main causes of cancer-related deaths, there are still no approved management strategies for the disease. The etiology of this condition is based on the upregulation of systemic inflammation factors and catabolic stimuli, resulting in the inhibition of protein synthesis and enhancement of protein degradation. Numerous necessary cellular processes are disrupted by cachectic pathology, which mediate intracellular signalling pathways resulting in the net loss of muscle and organelles. However, the exact underpinning molecular mechanisms of how these changes are orchestrated are incompletely understood. Much work is still required, but structured exercise has the capacity to counteract numerous detrimental effects linked to cancer cachexia. Primarily through the stimulation of muscle protein synthesis, enhancement of mitochondrial function, and the release of myokines. As a result, muscle mass and strength increase, leading to improved mobility, and quality-of-life. This review summarises existing knowledge of the complex molecular networks that regulate cancer cachexia and exercise, highlighting the molecular interplay between the two for potential therapeutic intervention. Finally, the utility of mass spectrometry-based proteomics is considered as a way of establishing early diagnostic biomarkers of cachectic patients.
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Botella J, Shaw CS, Bishop DJ. Autophagy and Exercise: Current Insights and Future Research Directions. Int J Sports Med 2024; 45:171-182. [PMID: 37582398 DOI: 10.1055/a-2153-9258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/17/2023]
Abstract
Autophagy is a cellular process by which proteins and organelles are degraded inside the lysosome. Exercise is known to influence the regulation of autophagy in skeletal muscle. However, as gold standard techniques to assess autophagy flux in vivo are restricted to animal research, important gaps remain in our understanding of how exercise influences autophagy activity in humans. Using available datasets, we show how the gene expression profile of autophagy receptors and ATG8 family members differ between human and mouse skeletal muscle, providing a potential explanation for their differing exercise-induced autophagy responses. Furthermore, we provide a comprehensive view of autophagy regulation following exercise in humans by summarizing human transcriptomic and phosphoproteomic datasets that provide novel targets of potential relevance. These newly identified phosphorylation sites may provide an explanation as to why both endurance and resistance exercise lead to an exercise-induced reduction in LC3B-II, while possibly divergently regulating autophagy receptors, and, potentially, autophagy flux. We also provide recommendations to use ex vivo autophagy flux assays to better understand the influence of exercise, and other stimuli, on autophagy regulation in humans. This review provides a critical overview of the field and directs researchers towards novel research areas that will improve our understanding of autophagy regulation following exercise in humans.
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Affiliation(s)
- Javier Botella
- Metabolic Research Unit, School of Medicine and Institute for Mental and Physical Health and Clinical Translation (IMPACT), Deakin University, Waurn Ponds, Victoria, Australia
| | - Christopher S Shaw
- Institute for Physical Activity and Nutrition (IPAN), School of Exercise and Nutrition Sciences, Deakin University, Geelong, 3216, VIC, Australia
| | - David J Bishop
- Institute for Health and Sport (iHeS), Victoria University, Melbourne, Australia
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4
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Ashcroft SP, Stocks B, Egan B, Zierath JR. Exercise induces tissue-specific adaptations to enhance cardiometabolic health. Cell Metab 2024; 36:278-300. [PMID: 38183980 DOI: 10.1016/j.cmet.2023.12.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Revised: 10/06/2023] [Accepted: 12/05/2023] [Indexed: 01/08/2024]
Abstract
The risk associated with multiple cancers, cardiovascular disease, diabetes, and all-cause mortality is decreased in individuals who meet the current recommendations for physical activity. Therefore, regular exercise remains a cornerstone in the prevention and treatment of non-communicable diseases. An acute bout of exercise results in the coordinated interaction between multiple tissues to meet the increased energy demand of exercise. Over time, the associated metabolic stress of each individual exercise bout provides the basis for long-term adaptations across tissues, including the cardiovascular system, skeletal muscle, adipose tissue, liver, pancreas, gut, and brain. Therefore, regular exercise is associated with a plethora of benefits throughout the whole body, including improved cardiorespiratory fitness, physical function, and glycemic control. Overall, we summarize the exercise-induced adaptations that occur within multiple tissues and how they converge to ultimately improve cardiometabolic health.
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Affiliation(s)
- Stephen P Ashcroft
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Ben Stocks
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Brendan Egan
- School of Health and Human Performance, Dublin City University, Dublin, Ireland
| | - Juleen R Zierath
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark; Integrative Physiology, Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden; Integrative Physiology, Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.
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5
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Soares JP, Cardoso R, Almeida V, Pereira AF, Silva AM, Mota MP. The Impact of 8 Weeks of Combined Physical Exercise Training on SIRT3 and mTOR in Lymphocytes, and on Lipid Peroxidation. Healthcare (Basel) 2024; 12:350. [PMID: 38338233 PMCID: PMC10855888 DOI: 10.3390/healthcare12030350] [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: 10/03/2023] [Revised: 01/15/2024] [Accepted: 01/17/2024] [Indexed: 02/12/2024] Open
Abstract
The sirtuins (SIRT) protein family and the mechanistic/mammalian target of rapamycin (mTOR) are intracellular molecules that have been involved in the regulation of several biological processes, as well as in various aging-related processes. This pilot study, in small scale, aimed to analyze the effects of an 8-week physical exercise program on SIRT3 and mTOR levels in lymphocytes, as well as on lipid peroxidation in middle aged and older men. A total of 9 participants aged between 56 and 73 years were enrolled in an 8-week physical exercise program comprising cardiovascular and high-intensity interval training. The program involved three sessions per week, each lasting 45-60 min, conducted on non-consecutive days. Tests were conducted before and after the experimental period (pre- and post-training). Assessments included a vertical jump, 20 m velocity, ball throwing, and an aerobic capacity test. Lipid peroxidation (MDA) was measured in plasma as an oxidative stress biomarker. Additionally, sirtuin 3 (SIRT3/β-actin) and mTOR (mTOR/β-actin) levels were measured in isolated lymphocytes extracted from venous blood. Following the exercise training period, our results demonstrated a significant improvement in aerobic capacity (pre-training: 615.4 ± 45.3 m; post-training: 687.2 ± 34.6 m; t = -2.521; p = 0.012) and 20 m velocity (pre-training: 4.6 ± 0.5 s; post-training: 4.3 ± 0.3 s; t = -2.023; p = 0.04). Concerning blood variables, there was a significant decrease in mTOR levels (pre-training: 0.857 ± 0.593; post-training: 0.214 ± 0.097; t = -2.547; p = 0.011), while no changes were observed in SIRT3 (pre-training: 0.608 ± 0.404; post-training: 0.516 ± 0.390; t = 0.533; p = 0.594) and MDA (pre-training: 8420 ± 4615; post-training: 8800 ± 3163; t = -0.533; p = 0.594). The notable reduction in mTOR levels in lymphocytes following the 8-week physical exercise program suggests a potential role of exercise in modulating immune cell dynamics, particularly in middle-aged and older individuals. Furthermore, the exercise regimen resulted in improvements in physical function, including enhanced aerobic capacity and walking velocity.
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Affiliation(s)
- Jorge Pinto Soares
- Research Centre in Sports Sciences, Health, and Human Development (CIDESD), 5001-801 Vila Real, Portugal;
- Department of Sport of Science Exercise and Health, School of Life and Environmental Sciences (ECVA), University of Trás-os-Montes and Alto Douro (UTAD), 5000-801 Vila Real, Portugal
| | - Ricardo Cardoso
- Centre for the Research and Technology of Agro-Environmental and Biological Sciences (CITAB), University of Trás-os-Montes and Alto Douro (UTAD), 5000-801 Vila Real, Portugal; (R.C.); (V.A.)
| | - Vanessa Almeida
- Centre for the Research and Technology of Agro-Environmental and Biological Sciences (CITAB), University of Trás-os-Montes and Alto Douro (UTAD), 5000-801 Vila Real, Portugal; (R.C.); (V.A.)
| | | | - Amélia M. Silva
- Centre for the Research and Technology of Agro-Environmental and Biological Sciences (CITAB), University of Trás-os-Montes and Alto Douro (UTAD), 5000-801 Vila Real, Portugal; (R.C.); (V.A.)
- Department of Biology and Environment, University of Trás-os-Montes and Alto Douro (UTAD), 5000-801 Vila Real, Portugal
| | - Maria Paula Mota
- Research Centre in Sports Sciences, Health, and Human Development (CIDESD), 5001-801 Vila Real, Portugal;
- Department of Sport of Science Exercise and Health, School of Life and Environmental Sciences (ECVA), University of Trás-os-Montes and Alto Douro (UTAD), 5000-801 Vila Real, Portugal
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Reitzner SM, Emanuelsson EB, Arif M, Kaczkowski B, Kwon AT, Mardinoglu A, Arner E, Chapman MA, Sundberg CJ. Molecular profiling of high-level athlete skeletal muscle after acute endurance or resistance exercise - A systems biology approach. Mol Metab 2024; 79:101857. [PMID: 38141850 PMCID: PMC10805945 DOI: 10.1016/j.molmet.2023.101857] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Revised: 12/13/2023] [Accepted: 12/18/2023] [Indexed: 12/25/2023] Open
Abstract
OBJECTIVE Long-term high-level exercise training leads to improvements in physical performance and multi-tissue adaptation following changes in molecular pathways. While skeletal muscle baseline differences between exercise-trained and untrained individuals have been previously investigated, it remains unclear how training history influences human multi-omics responses to acute exercise. METHODS We recruited and extensively characterized 24 individuals categorized as endurance athletes with >15 years of training history, strength athletes or control subjects. Timeseries skeletal muscle biopsies were taken from M. vastus lateralis at three time-points after endurance or resistance exercise was performed and multi-omics molecular analysis performed. RESULTS Our analyses revealed distinct activation differences of molecular processes such as fatty- and amino acid metabolism and transcription factors such as HIF1A and the MYF-family. We show that endurance athletes have an increased abundance of carnitine-derivates while strength athletes increase specific phospholipid metabolites compared to control subjects. Additionally, for the first time, we show the metabolite sorbitol to be substantially increased with acute exercise. On transcriptional level, we show that acute resistance exercise stimulates more gene expression than acute endurance exercise. This follows a specific pattern, with endurance athletes uniquely down-regulating pathways related to mitochondria, translation and ribosomes. Finally, both forms of exercise training specialize in diverging transcriptional directions, differentiating themselves from the transcriptome of the untrained control group. CONCLUSIONS We identify a "transcriptional specialization effect" by transcriptional narrowing and intensification, and molecular specialization effects on metabolomic level Additionally, we performed multi-omics network and cluster analysis, providing a novel resource of skeletal muscle transcriptomic and metabolomic profiling in highly trained and untrained individuals.
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Affiliation(s)
- Stefan M Reitzner
- Department Physiology & Pharmacology, Karolinska Institutet, Solnavägen 9, 171 77 Stockholm, Sweden; Department Women's and Children's Health, Karolinska Institutet, Solnavägen 9, 171 77 Stockholm, Sweden.
| | - Eric B Emanuelsson
- Department Physiology & Pharmacology, Karolinska Institutet, Solnavägen 9, 171 77 Stockholm, Sweden
| | - Muhammad Arif
- Science for Life Laboratory, KTH - Royal Institute of Technology, Tomtebodavägen 23, 171 65 Stockholm, Sweden
| | - Bogumil Kaczkowski
- Center for Integrative Medical Sciences, RIKEN Yokohama, 1 Chome-7-22 Suehirocho, Tsurumi Ward, Yokohama, Kanagawa 230-0045, Japan
| | - Andrew Tj Kwon
- Center for Integrative Medical Sciences, RIKEN Yokohama, 1 Chome-7-22 Suehirocho, Tsurumi Ward, Yokohama, Kanagawa 230-0045, Japan
| | - Adil Mardinoglu
- Science for Life Laboratory, KTH - Royal Institute of Technology, Tomtebodavägen 23, 171 65 Stockholm, Sweden; Centre for Host-Microbiome Interactions, Faculty of Dentistry, Oral & Craniofacial Sciences, King's College London, Guy's Hospital, Great Maze Pond, London, SE1 1UL, United Kingdom
| | - Erik Arner
- Center for Integrative Medical Sciences, RIKEN Yokohama, 1 Chome-7-22 Suehirocho, Tsurumi Ward, Yokohama, Kanagawa 230-0045, Japan; Graduate School of Integrated Sciences for Life, Hiroshima University, 1 Chome-3-3-2 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-0046, Japan
| | - Mark A Chapman
- Department Physiology & Pharmacology, Department Women's and Children's Health, Karolinska Institutet, Solnavägen 9, 171 77 Stockholm, Sweden; Department of Integrated Engineering, University of San Diego, 5998 Alcalà Park, San Diego, CA 92110, USA
| | - Carl Johan Sundberg
- Department Physiology & Pharmacology, Department Women's and Children's Health, Karolinska Institutet, Solnavägen 9, 171 77 Stockholm, Sweden; Department of Learning, Informatics, Management and Ethics, Karolinska Institutet, Tomtebodavägen 18A, 171 65 Solna, Sweden; Department of Laboratory Medicine, Karolinska Institutet, Alfred Nobels Allé 8, 141 52 Huddinge, Sweden
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7
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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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8
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Roberts MD, McCarthy JJ, Hornberger TA, Phillips SM, Mackey AL, Nader GA, Boppart MD, Kavazis AN, Reidy PT, Ogasawara R, Libardi CA, Ugrinowitsch C, Booth FW, Esser KA. Mechanisms of mechanical overload-induced skeletal muscle hypertrophy: current understanding and future directions. Physiol Rev 2023; 103:2679-2757. [PMID: 37382939 PMCID: PMC10625844 DOI: 10.1152/physrev.00039.2022] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Revised: 06/12/2023] [Accepted: 06/21/2023] [Indexed: 06/30/2023] Open
Abstract
Mechanisms underlying mechanical overload-induced skeletal muscle hypertrophy have been extensively researched since the landmark report by Morpurgo (1897) of "work-induced hypertrophy" in dogs that were treadmill trained. Much of the preclinical rodent and human resistance training research to date supports that involved mechanisms include enhanced mammalian/mechanistic target of rapamycin complex 1 (mTORC1) signaling, an expansion in translational capacity through ribosome biogenesis, increased satellite cell abundance and myonuclear accretion, and postexercise elevations in muscle protein synthesis rates. However, several lines of past and emerging evidence suggest that additional mechanisms that feed into or are independent of these processes are also involved. This review first provides a historical account of how mechanistic research into skeletal muscle hypertrophy has progressed. A comprehensive list of mechanisms associated with skeletal muscle hypertrophy is then outlined, and areas of disagreement involving these mechanisms are presented. Finally, future research directions involving many of the discussed mechanisms are proposed.
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Affiliation(s)
- Michael D Roberts
- School of Kinesiology, Auburn University, Auburn, Alabama, United States
| | - John J McCarthy
- Department of Physiology, College of Medicine, University of Kentucky, Lexington, Kentucky, United States
| | - Troy A Hornberger
- Department of Comparative Biosciences, University of Wisconsin-Madison, Madison, Wisconsin, United States
| | - Stuart M Phillips
- Department of Kinesiology, McMaster University, Hamilton, Ontario, Canada
| | - Abigail L Mackey
- Institute of Sports Medicine Copenhagen, Department of Orthopedic Surgery, Copenhagen University Hospital-Bispebjerg and Frederiksberg, and Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Gustavo A Nader
- Department of Kinesiology and Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, Pennsylvania, United States
| | - Marni D Boppart
- Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States
| | - Andreas N Kavazis
- School of Kinesiology, Auburn University, Auburn, Alabama, United States
| | - Paul T Reidy
- Department of Kinesiology, Nutrition and Health, Miami University, Oxford, Ohio, United States
| | - Riki Ogasawara
- Healthy Food Science Research Group, Cellular and Molecular Biotechnology Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Japan
| | - Cleiton A Libardi
- MUSCULAB-Laboratory of Neuromuscular Adaptations to Resistance Training, Department of Physical Education, Federal University of São Carlos, São Carlos, Brazil
| | - Carlos Ugrinowitsch
- School of Physical Education and Sport, University of São Paulo, São Paulo, Brazil
| | - Frank W Booth
- Department of Biomedical Sciences, University of Missouri, Columbia, Missouri, United States
| | - Karyn A Esser
- Department of Physiology and Aging, College of Medicine, University of Florida, Gainesville, Florida, United States
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Influence of mTOR-regulated anabolic pathways on equine skeletal muscle health. J Equine Vet Sci 2023; 124:104281. [PMID: 36905972 DOI: 10.1016/j.jevs.2023.104281] [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: 03/01/2023] [Revised: 03/04/2023] [Accepted: 03/06/2023] [Indexed: 03/11/2023]
Abstract
Skeletal muscle is a highly dynamic organ that is essential for locomotion as well as endocrine regulation in all populations of horses. However, despite the importance of adequate muscle development and maintenance, the mechanisms underlying protein anabolism in horses on different diets, exercise programs, and at different life stages remain obscure. Mechanistic target of rapamycin (mTOR) is a key component of the protein synthesis pathway and is regulated by biological factors such as insulin and amino acid availability. Providing a diet ample in vital amino acids, such as leucine and glutamine, is essential in activating sensory pathways that recruit mTOR to the lysosome and assist in the translation of important downstream targets. When the diet is well balanced, mitochondrial biogenesis and protein synthesis are activated in response to increased exercise bouts in the performing athlete. It is important to note that the mTOR kinase pathways are multi-faceted and very complex, with several binding partners and targets that lead to specific functions in protein turnover of the cell, and ultimately, the capacity to maintain or grow muscle mass. Further, these pathways are likely altered across the lifespan, with an emphasis of growth in young horses while decreases in musculature with aged horses appears to be attributable to degradation or other regulators of protein synthesis rather than alterations in the mTOR pathway. Previous work has begun to pinpoint ways in which the mTOR pathway is influenced by diet, exercise, and age; however, future research is warranted to quantify the functional outcomes related to changes in mTOR. Promisingly, this could provide direction on appropriate management techniques to support skeletal muscle growth and maximize athletic potential in differing equine populations.
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10
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Alcohol, Resistance Exercise, and mTOR Pathway Signaling: An Evidence-Based Narrative Review. Biomolecules 2022; 13:biom13010002. [PMID: 36671386 PMCID: PMC9855961 DOI: 10.3390/biom13010002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Revised: 12/14/2022] [Accepted: 12/17/2022] [Indexed: 12/24/2022] Open
Abstract
Skeletal muscle mass is determined by the balance between muscle protein synthesis (MPS) and degradation. Several intracellular signaling pathways control this balance, including mammalian/mechanistic target of rapamycin (mTOR) complex 1 (C1). Activation of this pathway in skeletal muscle is controlled, in part, by nutrition (e.g., amino acids and alcohol) and exercise (e.g., resistance exercise (RE)). Acute and chronic alcohol use can result in myopathy, and evidence points to altered mTORC1 signaling as a contributing factor. Moreover, individuals who regularly perform RE or vigorous aerobic exercise are more likely to use alcohol frequently and in larger quantities. Therefore, alcohol may antagonize beneficial exercise-induced increases in mTORC1 pathway signaling. The purpose of this review is to synthesize up-to-date evidence regarding mTORC1 pathway signaling and the independent and combined effects of acute alcohol and RE on activation of the mTORC1 pathway. Overall, acute alcohol impairs and RE activates mTORC1 pathway signaling; however, effects vary by model, sex, feeding, training status, quantity, etc., such that anabolic stimuli may partially rescue the alcohol-mediated pathway inhibition. Likewise, the impact of alcohol on RE-induced mTORC1 pathway signaling appears dependent on several factors including nutrition and sex, although many questions remain unanswered. Accordingly, we identify gaps in the literature that remain to be elucidated to fully understand the independent and combined impacts of alcohol and RE on mTORC1 pathway signaling.
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11
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Reed CH, Buhr TJ, Tystahl AC, Bauer EE, Clark PJ, Valentine RJ. The effects of voluntary binge-patterned ethanol ingestion and daily wheel running on signaling of muscle protein synthesis and degradation in female mice. Alcohol 2022; 104:45-52. [PMID: 35926812 DOI: 10.1016/j.alcohol.2022.06.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 06/17/2022] [Accepted: 06/22/2022] [Indexed: 01/26/2023]
Abstract
Excessive ethanol ingestion can reduce skeletal muscle protein synthesis (MPS) through the disruption of signaling along the Akt-mTOR pathway and increase muscle protein degradation (MPD) through the Ubiquitin Proteasome Pathway (UPP) and autophagy. Identification of interventions that curb the disrupting effects of alcohol misuse on MPS and MPD are of central importance for the prevention of chronic health complications that arise from muscle loss. Physical activity is one potential strategy to combat the deleterious effects of alcohol on skeletal muscle. Therefore, the purpose of this study was to investigate the interaction between daily wheel running and binge-patterned ethanol consumption, through episodes of voluntary binge-patterned ethanol drinking, on signaling factors along the Akt-mTOR, Ubiquitin-Proteasome, and autophagy pathways. Adult female C57BL/6J mice received daily access to cages with or without running wheels for 2.5 h/day for five weeks. During the final five days of the study, mice received 2-4 h of daily access to sipper tubes containing water (n = 14 sedentary; n = 15 running) or 20% ethanol (n = 14 sedentary; n = 16 running) 30 min after running wheel access, using the "Drinking in the Dark" (DID) model of binge-patterned ethanol consumption. Immediately after the final episode of DID, gastrocnemius muscle was extracted. Western blotting was performed to measure proteins along Akt-mTOR, Ubiquitin-Proteasome, and autophagy pathways, and PCR was used to assess mRNA expression of atrogenes. Ethanol access increased expression of MAFbx by 82% (p = 0.048), but did not robustly influence Akt-mTOR or UPP signaling. Daily wheel access did not prevent alcohol-induced MAFbx expression; however, ethanol access decreased the phosphorylation of p70S6K by 45% in running mice (p = 0.020). These results suggest that physical activity may be insufficient to prevent alcohol-induced changes to signaling factors along pathways involved in muscle loss. Instead, binge-patterned ethanol ingestion may impair the benefits of physical activity on factors involved in MPS.
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Affiliation(s)
- Carter H Reed
- Department of Kinesiology, Forker Building, 534 Wallace Road, Iowa State University, Ames, IA, 50011, United States; Interdepartmental Graduate Program of Nutritional Sciences, MacKay Hall, 2302 Osborn Drive, Iowa State University, Ames, IA, 50011, United States
| | - Trevor J Buhr
- Neuroscience Program, MacKay Hall, 2302 Osborn Drive, Iowa State University, Ames, IA, 50011, United States; Department of Food Science and Human Nutrition, MacKay Hall, 2302 Osborn Drive, Iowa State University, Ames, IA, 50011, United States
| | - Anna C Tystahl
- Department of Kinesiology, Forker Building, 534 Wallace Road, Iowa State University, Ames, IA, 50011, United States
| | - Ella E Bauer
- Interdepartmental Graduate Program of Nutritional Sciences, MacKay Hall, 2302 Osborn Drive, Iowa State University, Ames, IA, 50011, United States; Neuroscience Program, MacKay Hall, 2302 Osborn Drive, Iowa State University, Ames, IA, 50011, United States; Department of Food Science and Human Nutrition, MacKay Hall, 2302 Osborn Drive, Iowa State University, Ames, IA, 50011, United States
| | - Peter J Clark
- Interdepartmental Graduate Program of Nutritional Sciences, MacKay Hall, 2302 Osborn Drive, Iowa State University, Ames, IA, 50011, United States; Neuroscience Program, MacKay Hall, 2302 Osborn Drive, Iowa State University, Ames, IA, 50011, United States; Department of Food Science and Human Nutrition, MacKay Hall, 2302 Osborn Drive, Iowa State University, Ames, IA, 50011, United States.
| | - Rudy J Valentine
- Department of Kinesiology, Forker Building, 534 Wallace Road, Iowa State University, Ames, IA, 50011, United States; Interdepartmental Graduate Program of Nutritional Sciences, MacKay Hall, 2302 Osborn Drive, Iowa State University, Ames, IA, 50011, United States; Neuroscience Program, MacKay Hall, 2302 Osborn Drive, Iowa State University, Ames, IA, 50011, United States.
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Blazev R, Carl CS, Ng YK, Molendijk J, Voldstedlund CT, Zhao Y, Xiao D, Kueh AJ, Miotto PM, Haynes VR, Hardee JP, Chung JD, McNamara JW, Qian H, Gregorevic P, Oakhill JS, Herold MJ, Jensen TE, Lisowski L, Lynch GS, Dodd GT, Watt MJ, Yang P, Kiens B, Richter EA, Parker BL. Phosphoproteomics of three exercise modalities identifies canonical signaling and C18ORF25 as an AMPK substrate regulating skeletal muscle function. Cell Metab 2022; 34:1561-1577.e9. [PMID: 35882232 DOI: 10.1016/j.cmet.2022.07.003] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 05/31/2022] [Accepted: 07/08/2022] [Indexed: 11/03/2022]
Abstract
Exercise induces signaling networks to improve muscle function and confer health benefits. To identify divergent and common signaling networks during and after different exercise modalities, we performed a phosphoproteomic analysis of human skeletal muscle from a cross-over intervention of endurance, sprint, and resistance exercise. This identified 5,486 phosphosites regulated during or after at least one type of exercise modality and only 420 core phosphosites common to all exercise. One of these core phosphosites was S67 on the uncharacterized protein C18ORF25, which we validated as an AMPK substrate. Mice lacking C18ORF25 have reduced skeletal muscle fiber size, exercise capacity, and muscle contractile function, and this was associated with reduced phosphorylation of contractile and Ca2+ handling proteins. Expression of C18ORF25 S66/67D phospho-mimetic reversed the decreased muscle force production. This work defines the divergent and canonical exercise phosphoproteome across different modalities and identifies C18ORF25 as a regulator of exercise signaling and muscle function.
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Affiliation(s)
- Ronnie Blazev
- Department of Anatomy & Physiology, The University of Melbourne, Parkville, VIC, Australia; Centre for Muscle Research, The University of Melbourne, Parkville, VIC, Australia
| | - Christian S Carl
- August Krogh Section for Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, The University of Copenhagen, Copenhagen, Denmark
| | - Yaan-Kit Ng
- Department of Anatomy & Physiology, The University of Melbourne, Parkville, VIC, Australia; Centre for Muscle Research, The University of Melbourne, Parkville, VIC, Australia
| | - Jeffrey Molendijk
- Department of Anatomy & Physiology, The University of Melbourne, Parkville, VIC, Australia; Centre for Muscle Research, The University of Melbourne, Parkville, VIC, Australia
| | - Christian T Voldstedlund
- August Krogh Section for Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, The University of Copenhagen, Copenhagen, Denmark
| | - Yuanyuan Zhao
- Department of Anatomy & Physiology, The University of Melbourne, Parkville, VIC, Australia
| | - Di Xiao
- Children's Medical Research Institute, The University of Sydney, Camperdown, NSW, Australia; School of Mathematics and Statistics, The University of Sydney, Camperdown, NSW, Australia
| | - Andrew J Kueh
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia
| | - Paula M Miotto
- Department of Anatomy & Physiology, The University of Melbourne, Parkville, VIC, Australia
| | - Vanessa R Haynes
- Department of Anatomy & Physiology, The University of Melbourne, Parkville, VIC, Australia
| | - Justin P Hardee
- Department of Anatomy & Physiology, The University of Melbourne, Parkville, VIC, Australia; Centre for Muscle Research, The University of Melbourne, Parkville, VIC, Australia
| | - Jin D Chung
- Department of Anatomy & Physiology, The University of Melbourne, Parkville, VIC, Australia; Centre for Muscle Research, The University of Melbourne, Parkville, VIC, Australia
| | - James W McNamara
- Department of Anatomy & Physiology, The University of Melbourne, Parkville, VIC, Australia; Centre for Muscle Research, The University of Melbourne, Parkville, VIC, Australia; Murdoch Children's Research Institute and Melbourne Centre for Cardiovascular Genomics and Regenerative Medicine, The Royal Children's Hospital, Parkville, VIC, Australia
| | - Hongwei Qian
- Department of Anatomy & Physiology, The University of Melbourne, Parkville, VIC, Australia; Centre for Muscle Research, The University of Melbourne, Parkville, VIC, Australia
| | - Paul Gregorevic
- Department of Anatomy & Physiology, The University of Melbourne, Parkville, VIC, Australia; Centre for Muscle Research, The University of Melbourne, Parkville, VIC, Australia
| | | | - Marco J Herold
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia
| | - Thomas E Jensen
- August Krogh Section for Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, The University of Copenhagen, Copenhagen, Denmark
| | - Leszek Lisowski
- Children's Medical Research Institute, The University of Sydney, Camperdown, NSW, Australia; Military Institute of Medicine, Warsaw, Poland
| | - Gordon S Lynch
- Department of Anatomy & Physiology, The University of Melbourne, Parkville, VIC, Australia; Centre for Muscle Research, The University of Melbourne, Parkville, VIC, Australia
| | - Garron T Dodd
- Department of Anatomy & Physiology, The University of Melbourne, Parkville, VIC, Australia
| | - Matthew J Watt
- Department of Anatomy & Physiology, The University of Melbourne, Parkville, VIC, Australia
| | - Pengyi Yang
- Children's Medical Research Institute, The University of Sydney, Camperdown, NSW, Australia; The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia
| | - Bente Kiens
- August Krogh Section for Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, The University of Copenhagen, Copenhagen, Denmark.
| | - Erik A Richter
- August Krogh Section for Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, The University of Copenhagen, Copenhagen, Denmark.
| | - Benjamin L Parker
- Department of Anatomy & Physiology, The University of Melbourne, Parkville, VIC, Australia; Centre for Muscle Research, The University of Melbourne, Parkville, VIC, Australia.
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13
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Loquat Leaf Extract Enhances Muscle Contraction-Induced Activation of Protein Synthesis Signaling in Rat Skeletal Muscle. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2022; 2022:2234118. [PMID: 35783523 PMCID: PMC9249488 DOI: 10.1155/2022/2234118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/05/2021] [Revised: 04/22/2022] [Accepted: 06/13/2022] [Indexed: 11/19/2022]
Abstract
Loquat (Eriobotrya japonica (Thunb.) Lindl.) leaves are traditionally used to improve muscle weakness, but their effects on muscle protein synthesis require further research. Therefore, we aimed to investigate whether loquat leaf extract (LLE) enhances muscle contraction-induced activation of muscle protein synthesis signaling. Male Wistar rats (12 weeks old, n = 6/group) were categorized into water treatment (CON) and LLE treatment (LLE) groups. The rats were administered distilled water or LLE (1.5 g/kg/day) once a day by oral gavage for 7 days. On day 7, at 3 h post-LLE administration, the gastrocnemius muscle in the right leg of each rat was stimulated by electrical muscle stimulation (EMS) (100 Hz, 30 V) through five sets of 10 isometric contractions (7 s contraction, 3 s rest) with 3 min interset intervals. The rats were then sacrificed, and the gastrocnemius muscles of both legs were excised at 3 h post-EMS. The phosphorylation levels of mammalian target of rapamycin complex 1 (mTORC1) signaling pathway molecules (Akt, mTOR, and p70S6K) were determined by Western blotting. Regarding the muscle contraction-induced protein synthesis signaling pathway, Akt phosphorylation at Ser473 was not significantly different between the CON and LLE groups. mTOR phosphorylation at Ser2448 was increased by EMS but did not show a significant difference between the CON and LLE groups. p70S6K phosphorylation at Thr389 was significantly increased in response to EMS, whereas the LLE group showed significantly higher p70S6K phosphorylation at Thr389 than that in the CON group. This suggests that LLE enhances muscle contraction-induced activation of p70S6K phosphorylation in rat skeletal muscles.
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