Mitotic activity of rat muscle satellite cells in response to serum stimulation: relation with cellular metabolism.
Cellular and molecular adaptations of satellite cells isolated from rat hindlimb muscles (n = 10) were investigated in response to serum stimulation. Flow cytometry analysis of the amounts of DNA and RNA indicated that 97.7 +/- 0.7% of satellite cells were in G0 at the end of the isolation procedure, whereas 93.2 +/- 2.0% of cells were cycling after serum exposure. The length of cell division was 34.0 +/- 2.8 h. Myoblast proliferation was asynchronous, suggesting the existence of heterogeneous cell populations in skeletal muscle. Myoblast proliferation was also accompanied by a significant increase in c-met expression, and major adaptations of energetic and proteolytic metabolisms, including an increase in the relative contribution of glycolytic metabolism for energy production, an increase in proteasome and matrix metalloproteinases 2 and 9 activities, and a decrease in plasminogen activator activities. Our data suggest that, along with molecular adaptations leading to cell cycle activation itself, adaptations in energetic and proteolytic metabolisms are crucial events involved in satellite cell activation and myoblast proliferation.
Barani
Aude E
AE
Laboratoire de Physiologie, Groupe Physiologie et Physiopathologie de l'Exercice et du Handicap, Groupement d'Intérêt Public-Exercice Sport Santé, Faculté de Médecine, 15 rue Ambroise Paré, 42023 Saint-Etienne, France.
Sabido
Odile
O
Freyssenet
Damien
D
D000818:Animals; D002455:Cell Division; D004247:DNA / Q000032:analysis; D004734:Energy Metabolism; D004798:Enzymes / Q000378:metabolism; D008297:Male; D008660:Metabolism / Q000187:drug effects; D008938:Mitosis / Q000187:drug effects*; D032446:Myoblasts / Q000166:cytology; D018809:Proliferating Cell Nuclear Antigen / Q000032:analysis; D019859:Proto-Oncogene Proteins c-met / Q000032:analysis; D012313:RNA / Q000032:analysis; D051381:Rats; D017207:Rats, Sprague-Dawley; D032496:Satellite Cells, Skeletal Muscle / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism*; D012709:Serum Albumin / Q000494:pharmacology*
D004798:Enzymes; D018809:Proliferating Cell Nuclear Antigen; D012709:Serum Albumin; D012313:RNA; D004247:DNA; D019859:Proto-Oncogene Proteins c-met