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Li C, White SH, Warren LK, Wohlgemuth SE. Effects of aging on mitochondrial function in skeletal muscle of American American Quarter Horses. J Appl Physiol (1985) 2016; 121:299-311. [PMID: 27283918 PMCID: PMC5040552 DOI: 10.1152/japplphysiol.01077.2015] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Accepted: 06/08/2016] [Indexed: 02/07/2023] Open
Abstract
Skeletal muscle function, aerobic capacity, and mitochondrial (Mt) function have been found to decline with age in humans and rodents. However, not much is known about age-related changes in Mt function in equine skeletal muscle. Here, we compared fiber-type composition and Mt function in gluteus medius and triceps brachii muscle between young (age 1.8 ± 0.1 yr, n = 24) and aged (age 17-25 yr, n = 10) American Quarter Horses. The percentage of myosin heavy chain (MHC) IIX was lower in aged compared with young muscles (gluteus, P = 0.092; triceps, P = 0.012), while the percentages of MHC I (gluteus; P < 0.001) and MHC IIA (triceps; P = 0.023) were increased. Mass-specific Mt density, indicated by citrate synthase activity, was unaffected by age in gluteus, but decreased in aged triceps (P = 0.023). Cytochrome-c oxidase (COX) activity per milligram tissue and per Mt unit decreased with age in gluteus (P < 0.001 for both) and triceps (P < 0.001 and P = 0.003, respectively). Activity of 3-hydroxyacyl-CoA dehydrogenase per milligram tissue was unaffected by age, but increased per Mt unit in aged gluteus and triceps (P = 0.023 and P < 0.001, respectively). Mt respiration of permeabilized muscle fibers per milligram tissue was unaffected by age in both muscles. Main effects of age appeared when respiration was normalized to Mt content, with increases in LEAK, oxidative phosphorylation capacity, and electron transport system capacity (P = 0.038, P = 0.045, and P = 0.007, respectively), independent of muscle. In conclusion, equine skeletal muscle aging was accompanied by a shift in fiber-type composition, decrease in Mt density and COX activity, but preserved Mt respiratory function.
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Affiliation(s)
- Chengcheng Li
- Department of Animal Sciences, University of Florida, Gainesville, Florida
| | - Sarah H White
- Department of Animal Sciences, University of Florida, Gainesville, Florida
| | - Lori K Warren
- Department of Animal Sciences, University of Florida, Gainesville, Florida
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Chaillou T, Kirby TJ, McCarthy JJ. Ribosome biogenesis: emerging evidence for a central role in the regulation of skeletal muscle mass. J Cell Physiol 2014; 229:1584-94. [PMID: 24604615 DOI: 10.1002/jcp.24604] [Citation(s) in RCA: 127] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2014] [Accepted: 03/04/2014] [Indexed: 12/17/2022]
Abstract
The ribosome is a supramolecular ribonucleoprotein complex that functions at the heart of the translation machinery to convert mRNA into protein. Ribosome biogenesis is the primary determinant of translational capacity of the cell and accordingly has an essential role in the control of cell growth in eukaryotes. Cumulative evidence supports the hypothesis that ribosome biogenesis has an important role in the regulation of skeletal muscle mass. The purpose of this review is to, first, summarize the main mechanisms known to regulate ribosome biogenesis and, second, put forth the hypothesis that ribosome biogenesis is a central mechanism used by skeletal muscle to regulate protein synthesis and control skeletal muscle mass in response to anabolic and catabolic stimuli. The mTORC1 and Wnt/β-catenin/c-myc signaling pathways are discussed as the major pathways that work in concert with each of the three RNA polymerases (RNA Pol I, II, and III) in regulating ribosome biogenesis. Consistent with our hypothesis, activation of these two pathways has been shown to be associated with ribosome biogenesis during skeletal muscle hypertrophy. Although further study is required, the finding that ribosome biogenesis is altered under catabolic states, in particular during disuse atrophy, suggests that its activation represents a novel therapeutic target to reduce or prevent muscle atrophy. Lastly, the emerging field of ribosome specialization is discussed and its potential role in the regulation of gene expression during periods of skeletal muscle plasticity.
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Affiliation(s)
- Thomas Chaillou
- Center for Muscle Biology, University of Kentucky, Lexington, Kentucky; Department of Physiology, College of Medicine, University of Kentucky, Lexington, Kentucky
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Role of exercise therapy in prevention of decline in aging muscle function: glucocorticoid myopathy and unloading. J Aging Res 2012; 2012:172492. [PMID: 22778959 PMCID: PMC3385633 DOI: 10.1155/2012/172492] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2011] [Accepted: 05/14/2012] [Indexed: 01/05/2023] Open
Abstract
Changes in skeletal muscle quantity and quality lead to disability in the aging population. Physiological changes in aging skeletal muscle are associated with a decline in mass, strength, and inability to maintain balance. Glucocorticoids, which are in wide exploitation in various clinical scenarios, lead to the loss of the myofibrillar apparatus, changes in the extracellular matrix, and a decrease in muscle strength and motor activity, particularly in the elderly. Exercise therapy has shown to be a useful tool for the prevention of different diseases, including glucocorticoid myopathy and muscle unloading in the elderly. The purpose of the paper is to discuss the possibilities of using exercise therapy in the prevention of glucocorticoid caused myopathy and unloading in the elderly and to describe relationships between the muscle contractile apparatus and the extracellular matrix in different types of aging muscles.
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Muscle weakness in the elderly: role of sarcopenia, dynapenia, and possibilities for rehabilitation. Eur Rev Aging Phys Act 2012. [DOI: 10.1007/s11556-012-0102-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Abstract
Aging is a multifactorial process leading to changes in skeletal muscle quantity and quality, which cause muscle weakness and disability in the aging population. This paper discusses the reasons for muscle weakness—and its biological and physiological mechanisms—in the elderly and describes the role of sarcopenia and dynapenia, and the possibilities to modify the age-associated decline in muscle function and decelerate the development of muscle weakness and disability. Resistance and endurance training are effective measures of exercise therapy in the elderly, which improve muscle metabolism and thereby muscle function and life quality.
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Seene T, Kaasik P, Riso EM. Review on aging, unloading and reloading: Changes in skeletal muscle quantity and quality. Arch Gerontol Geriatr 2012; 54:374-80. [DOI: 10.1016/j.archger.2011.05.002] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2010] [Revised: 05/04/2011] [Accepted: 05/05/2011] [Indexed: 11/29/2022]
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Age-Related Changes in Myosin Light and Heavy Chain Isoforms’ Composition in Gluteus Medius Muscle of Sedentary Akhal-Teke Horses. J Equine Vet Sci 2011. [DOI: 10.1016/j.jevs.2011.03.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Wu M, Fannin J, Rice KM, Wang B, Blough ER. Effect of aging on cellular mechanotransduction. Ageing Res Rev 2011; 10:1-15. [PMID: 19932197 DOI: 10.1016/j.arr.2009.11.002] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2009] [Revised: 11/11/2009] [Accepted: 11/16/2009] [Indexed: 12/27/2022]
Abstract
Aging is becoming a critical heath care issue and a burgeoning economic burden on society. Mechanotransduction is the ability of the cell to sense, process, and respond to mechanical stimuli and is an important regulator of physiologic function that has been found to play a role in regulating gene expression, protein synthesis, cell differentiation, tissue growth, and most recently, the pathophysiology of disease. Here we will review some of the recent findings of this field and attempt, where possible, to present changes in mechanotransduction that are associated with the aging process in several selected physiological systems, including musculoskeletal, cardiovascular, neuronal, respiratory systems and skin.
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Does AMP-activated protein kinase negatively mediate aged fast-twitch skeletal muscle mass? Exerc Sport Sci Rev 2008; 36:179-86. [PMID: 18815486 DOI: 10.1097/jes.0b013e3181877e13] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The activity of 5'-adenosine monophosphate (AMP)-activated protein kinase (AMPK), a negative regulator of cell size, is up-regulated with age in resting and overloaded fast-twitch skeletal muscle but not slow-twitch muscle. Here, we provide evidence to support the hypothesis that elevated AMPK activity plays a potentially important integrative role in the age-related atrophy and diminished capacity for growth specific to fast-twitch skeletal muscle.
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Adaptation of Equine Locomotor Muscle Fiber Types to Endurance and Intensive High Speed Training. J Equine Vet Sci 2008. [DOI: 10.1016/j.jevs.2008.05.007] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Kaasik P, Umnova M, Pehme A, Alev K, Aru M, Selart A, Seene T. Ageing and dexamethasone associated sarcopenia: peculiarities of regeneration. J Steroid Biochem Mol Biol 2007; 105:85-90. [PMID: 17587565 DOI: 10.1016/j.jsbmb.2006.11.024] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2006] [Accepted: 11/13/2006] [Indexed: 11/19/2022]
Abstract
The purpose of this study was to assess the development of ageing- and glucocorticoid-related sarcopenia on the level of myofibrillar apparatus, paying attention to the synthesis (SR) and degradation rate (DR) of contractile proteins, muscle strength, and daily motor activity. We also wanted to test the effect of ageing and dexamethasone (Dex) excess on the regeneration peculiarities of skeletal muscle autografts. Four and 30-month-old male rats of the Wistar strain were used. Ageing associated sarcopenia was calculated from gastrocnemius muscle relative mass decrease (from 5.6 +/- 0.08 to 3.35 +/- 0.04; p < 0.001). The SR of MyHC in old rats was approximately 30% and actin approximately 23% lower than in young rats. Dex treatment decreased SR of two main contractile proteins significantly in both age groups (p < 0.001) and increased DR during ageing from 2.11 +/- 0.15 to 4.09 +/- 0.29%/day (p < 0.001). Hindlimb grip strength in young rats was 5.90 +/- 0.35 N/100 g bw and 2.64 +/- 0.2 N/100 g bw (p < 0.001) in old rats. Autografts of old rats have a higher content of adipose tissue 14.9 +/- 1.1% in comparison with young rats 6.8 +/- 0.51% (p < 0.001) and less muscle tissue 39.8 +/- 2.6% and 48.3 +/- 2.8%, respectively (p < 0.05). Both, ageing and dex-caused sarcopenic muscles have diminished capacity for regeneration.
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Affiliation(s)
- Priit Kaasik
- Department of Functional Morphology, University of Tartu, Estonia.
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Eizema K, van der Wal DE, van den Burg MMM, Dingboom EG, Everts ME. Myosin heavy chain fibre type composition in foals: analyses at the mRNA and protein level. Equine Vet J 2007:316-21. [PMID: 17402439 DOI: 10.1111/j.2042-3306.2006.tb05560.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
REASONS FOR PERFORMING STUDY An optimal developed musculoskeletal system is vital for the performance of the horse. Previously, we showed that in the m. gluteus medius from adult untrained horses, identical mRNA and protein expression patterns were found in the majority of fibres. However, co-expression of IIa and IId/x myosin heavy chain (MyHC) was substantially more common at the protein than at the mRNA level, suggesting a transcriptionally controlled fine-tuning of these 2 genes. OBJECTIVE To analyse the MyHC transcripts and proteins (including the cardiac alpha isoform) in the same muscle during post natal development when the muscle is adapting to movement and load. METHODS Biopsies were taken from the m. gluteus medius of 2 Dutch Warmblood foals at 0, 2, 4, 22 and 48 weeks of age. mRNA was compared to protein expression on a fibre-to-fibre basis using in situ hybridisation and immunofluorescence. The MyHC slow (I), alpha, IIa and IId/x isoforms were analysed. RESULTS At all ages the expression of the mRNA and protein MyHC isoforms was almost identical. Surprisingly, coexpression of the IIad isoform was also detected at the mRNA level especially early in life. The transcript of the alpha isoform was only detectable at young age, indicating silencing of the gene around birth. CONCLUSION During the first year of life, MyHCs are continuously adapting at the mRNA and protein level. Additionally, the regulation of hybrid fibres is different from that in adult fibres. POTENTIAL RELEVANCE We postulate that interfering in this process by e.g. early training will be levelled out by the maturation of the muscle.
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Affiliation(s)
- K Eizema
- Department of Pathobiology, Faculty of Veterinary Medicine, Utrecht University, PO Box 80. 158, NL-3508, TD Utrecht, The Netherlands
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Thomson DM, Gordon SE. Impaired overload-induced muscle growth is associated with diminished translational signalling in aged rat fast-twitch skeletal muscle. J Physiol 2006; 574:291-305. [PMID: 16627569 PMCID: PMC1817794 DOI: 10.1113/jphysiol.2006.107490] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Impaired overload-induced protein synthesis and growth in aged fast-twitch skeletal muscle may result from diminished responsiveness of signalling intermediates controlling protein translation. Yet, potential age-related signalling decrements have never been examined in direct parallel with impaired overload-induced muscle growth in any model. To this end, we used Western blotting to examine the contents and phosphorylation states of mammalian target of rapamycin (mTOR) and its downstream translational signalling intermediates, 70 kDa ribosomal protein S6 kinase (S6k), ribosomal protein S6 (rpS6), eukaryotic elongation factor 2 (eEF2), and eukaryotic initiation factor 4E-binding protein 1 (4E-BP1), in conjunction with impaired growth in 1 week overloaded fast-twitch plantaris muscles (via unilateral gastrocnemius ablation) of old (O; 30 months) versus young adult (YA; 8 months) male Fischer344 x Brown Norway rats. The significantly (P <or= 0.05) diminished growth (assessed by total muscle protein content) in overloaded O muscles (5.6 +/- 1.7 versus 19.3 +/- 2.9% in YA) was accompanied by significant impairments in the phosphorylation states of mTOR (Ser2448), S6k (impaired at the mTOR-specific Thr389 residue but not at Thr421/Ser424), rpS6 (Ser235/236) and 4E-BP1 (gel shift), as well as deficits in total eEF2 accretion. Moreover, in overloaded muscles across both age groups, phospho-S6k at Thr389 (but not at Thr421/Ser424), 4E-BP1 phosphorylation status, and total eEF2 accretion were all positively correlated with percentage muscle hypertrophy, and negatively correlated with the phosphorylation (Thr172) of 5'-AMP-activated protein kinase (AMPK; which inhibits translational signalling and protein synthesis in young muscle at rest). As previously published by ourselves, AMPK was hyperphosphorylated in O versus YA muscles used in the current investigation. The present results provide solid evidence that impaired overload-induced growth in aged fast-twitch muscle may partly result from multiple-level decrements in signalling pathway(s) controlling protein translation, and also provide an initial indication that AMPK hyperactivation with age may potentially lie upstream of these decrements.
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Affiliation(s)
- David M Thomson
- Human Performance Laboratory, 363 Ward Sports Medicine Building, East Carolina University, Greenville, NC 27858, USA
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Lucas M, Heiss CJ. Protein Needs of Older Adults Engaged in Resistance Training: A Review. J Aging Phys Act 2005; 13:223-36. [PMID: 15995267 DOI: 10.1123/japa.13.2.223] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Protein recommendations by some professional organizations for young adults engaged in resistance training (RT) are higher than the recommended dietary allowance (RDA), but recommendations for resistance-training older adults (>50 years old) are not well characterized. Some argue that the current RDA is adequate, but others indicate increased protein needs. Although concerns have been raised about the consequences of high protein intake, protein intake above the RDA in older adults is associated with increased bone-mineral density when calcium intake is adequate and does not appear to compromise renal health in older individuals with normal renal function. Individual protein needs for older adults in RT are likely highly variable according to health and training regimen, but an intake of 1.0–1.3 g · kg−1· day−1should adequately and safely meet the needs of older adults engaged in RT, provided that their energy needs are met.
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Affiliation(s)
- Maureen Lucas
- Biomedical Sciences Dept., Southwest Missouri State University, Springfield 65804-0094, USA
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