title: Moderate-intensity treadmill running promotes expansion of the satellite cell pool in young and old mice.
abstract: Satellite cells, the myogenic progenitors located at the myofibre surface, are essential for the repair of adult skeletal muscle. There is ample evidence for an age-linked decline in the number of satellite cells and performance in limb muscles. Hence, an effective means of activating and expanding the satellite cell pool may enhance muscle maintenance and reduce the impact of age-associated muscle deterioration (sarcopaenia). Accordingly, in the present study, we explored the beneficial effects of endurance exercise on satellite cells in young and old mice. Animals were subjected to an 8-week moderate-intensity treadmill-running approach that does not inflict apparent muscle damage (0° inclination, 11.5 m·min(-1) for 30 min·day(-1) , 6 days·week(-1) ). Myofibres of extensor digitorum longus muscles were then isolated from exercised and sedentary mice and used for monitoring the number of satellite cells, as well as for harvesting individual satellite cells for clonal growth assays. We specifically focused on satellite cell pools of single myofibres, with the view that daily wear of muscles probably affects individual myofibres rather than causing overall muscle damage. We found an expansion of the satellite cell pool in the exercised groups compared to the sedentary groups, with the same increase (~ 1.6-fold) in both ages. The results of the present study are in agreement with our findings obtained using rat gastrocnemius, indicating the consistent effect of exercise on satellite cell expansion in limb muscles. The experimental paradigm established in the present study is useful for investigating satellite cell dynamics at the myofibre niche, as well as for broader investigations of the impact of physiologically and pathologically relevant factors on adult myogenesis.
authors: Department of Cell and Developmental Biology, Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel. gabish@tasmc.health.gov.il
authors: Gabi
authors: G
authors: Shefer
authors: Gat
authors: G
authors: Rauner
authors: Pascal
authors: P
authors: Stuelsatz
authors: Dafna
authors: D
authors: Benayahu
authors: Zipora
authors: Z
authors: Yablonka-Reuveni
mesh_terms: D000818:Animals; D049109:Cell Proliferation; D002478:Cells, Cultured; D005080:Exercise Test; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D007381:Intermediate Filament Proteins / Q000235:genetics; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D024510:Muscle Development / Q000502:physiology*; D018485:Muscle Fibers, Skeletal / Q000166:cytology* / Q000502:physiology; D009419:Nerve Tissue Proteins / Q000235:genetics; D064231:Nestin; D011401:Promoter Regions, Genetic / Q000235:genetics; D012420:Running / Q000502:physiology*; D032496:Satellite Cells, Skeletal Muscle / Q000166:cytology* / Q000502:physiology; D013234:Stem Cells / Q000166:cytology* / Q000502:physiology
chemical_list: D007381:Intermediate Filament Proteins; D009419:Nerve Tissue Proteins; C577485:Nes protein, mouse; C577486:Nes protein, rat; D064231:Nestin; D049452:Green Fluorescent Proteins
keywords: ageing; endurance exercise; nestin-GFP; satellite cells; skeletal muscle