Molecular regulation of skeletal muscle mass.
1. The maintenance of skeletal muscle mass is determined by a fine balance between protein synthesis and protein degradation. Skeletal mass is increased when there is a net gain in protein synthesis, which can occur following progressive exercise training. In contrast, skeletal muscle mass is lost when degradation occurs more rapidly than synthesis and is observed in numerous conditions, including neuromuscular disease, chronic disease, ageing, as well as following limb immobilization or prolonged bed rest due to injury or trauma. 2. Understanding the molecular pathways that regulate skeletal muscle protein synthesis and degradation is vital for identifying potential therapeutic targets that can attenuate muscle atrophy during disease and disuse. 3. The regulation of skeletal mass is complex and involves the precise coordination of several intracellular signalling pathways. The present review focuses on the role and regulation of pathways involving Akt, atrogin-1 and muscle ring finger-1 (MuRF1; atrogenes), peroxisome proliferator-activated receptor-gamma coactivator-1alpha (PGC-1alpha) and striated activator of Rho signalling (STARS), with exercise and disease.
Russell
Aaron P
AP
Centre for Physical Activity and Nutrition, School of Exercise and Nutrition Sciences, Deakin University, Burwood, Victoria, Australia. aaron.russell@deakin.edu.au
D000818:Animals; D015444:Exercise / Q000502:physiology; D006360:Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D006801:Humans; D009124:Muscle Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*; D009133:Muscular Atrophy / Q000235:genetics / Q000378:metabolism; D000071248:Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; D015398:Signal Transduction / Q000235:genetics / Q000502:physiology*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism / Q000502:physiology
D006360:Heat-Shock Proteins; D009124:Muscle Proteins; C486497:PPARGC1A protein, human; D000071248:Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; D014157:Transcription Factors