Muscle regeneration occurs to coincide with mitochondrial biogenesis.
We investigated the expression of the nuclear-encoded genes controlling the mitochondrial properties in the mouse gastrocnemius muscle to gain insight into the mitochondrial biogenesis that occurs during the muscle degeneration/regeneration induced by freezing. In addition, we tested whether the muscle regeneration is affected by pharmacologically blocking the mitochondrial protein synthesis to elucidate the possible involvement of mitochondrial biogenesis in muscle regeneration. The activity of citrate synthase dramatically increased soon after the initial injury when the myoblasts began to differentiate into myotubes, indicating that mitochondrial biogenesis occurs early during the muscle regeneration. At the same time, the expression of mitochondrial biogenesis-related genes including PGC-1β, PRC, NRF-1, NRF-2, TFAM, mtSSB, fission 1, and Lon protease synchronized with that of the myogenic regulatory genes including MyoD and myogenin. The skeletal muscles forced to regenerate in the presence of chloramphenicol to block the mitochondrial protein synthesis were of poor repair with small myofibers and an increased amount of connective tissue. These results suggest that mitochondrial biogenesis activated early during the muscle regeneration and that mitochondrial biogenesis plays a role in muscle regeneration.
Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Tokyo, Japan. wagatsuma1969@yahoo.co.jp
Akira
A
Wagatsuma
Naoki
N
Kotake
Shigeru
S
Yamada
D000818:Animals; D002950:Citrate (si)-Synthase / Q000235:genetics / Q000378:metabolism; D004789:Enzyme Activation; D057075:Enzyme Assays; D005260:Female; D020558:GTP Phosphohydrolases / Q000235:genetics; D020869:Gene Expression Profiling; D051379:Mice; D008931:Mitochondria, Muscle / Q000235:genetics* / Q000378:metabolism; D024101:Mitochondrial Proteins / Q000096:biosynthesis* / Q000235:genetics; D018482:Muscle, Skeletal / Q000201:enzymology / Q000502:physiology*; D049070:Protease La / Q000235:genetics; D012038:Regeneration; D014158:Transcription, Genetic
D024101:Mitochondrial Proteins; D002950:Citrate (si)-Synthase; D049070:Protease La; D020558:GTP Phosphohydrolases; C488751:Mfn2 protein, mouse