title: Type I muscle atrophy caused by microgravity-induced decrease of myocyte enhancer factor 2C (MEF2C) protein expression.
abstract: To investigate the molecular mechanisms of muscle atrophy under microgravity, the paraspinal muscles of rats after 14 days spaceflight and those of ground-based controls were examined. In the microgravitational environment, expressions of 42 genes changed, and the expressions of heat shock protein 70 and t complex polypeptide 1 increased. In Northern blotting, myocyte-specific enhancer binding factor 2C (MEF2C) and MEF2C-related genes including aldolase A and muscle ankyrin decreased. After 9 days ground recovery, expression of MEF2C increased and it was located mainly on the satellite cells in the muscle regeneration state. MEF2C could be a key transcriptional factor for skeletal muscle atrophy and regeneration under microgravity.
authors.affiliation: Department of Molecular Laboratory Medicine, Kagoshima University School of Medicine, 8-35-1 Sakuragaoka, Kagoshima 890-8520, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Yamakuchi
authors.forename: I
authors.initials: I
authors.lastname: Higuchi
authors.forename: S
authors.initials: S
authors.lastname: Masuda
authors.forename: Y
authors.initials: Y
authors.lastname: Ohira
authors.forename: T
authors.initials: T
authors.lastname: Kubo
authors.forename: Y
authors.initials: Y
authors.lastname: Kato
authors.forename: I
authors.initials: I
authors.lastname: Maruyama
authors.forename: I
authors.initials: I
authors.lastname: Kitajima
mesh_terms: D000818:Animals; D004247:DNA / Q000235:genetics / Q000378:metabolism; D015536:Down-Regulation; D020869:Gene Expression Profiling; D064326:MEF2 Transcription Factors; D008297:Male; D008856:Microscopy, Fluorescence; D018657:Muscle Fibers, Slow-Twitch / Q000378:metabolism / Q000473:pathology; D018482:Muscle, Skeletal / Q000378:metabolism* / Q000473:pathology* / Q000502:physiology; D009133:Muscular Atrophy / Q000235:genetics / Q000378:metabolism*; D018006:Myogenic Regulatory Factors / Q000235:genetics / Q000378:metabolism*; D018995:Myosin Heavy Chains / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D012038:Regeneration; D013026:Space Flight; D013997:Time Factors; D014893:Weightlessness / Q000009:adverse effects*
chemical_list: D064326:MEF2 Transcription Factors; D018006:Myogenic Regulatory Factors; D012333:RNA, Messenger; D004247:DNA; D018995:Myosin Heavy Chains