title: Hypoxia induces adipogenic differentitation of myoblastic cell lines.
abstract: Muscle atrophy usually accompanies fat accumulation in the muscle. In such atrophic conditions as back muscles of kyphotic spine and the rotator cuff muscles with torn tendons, blood flow might be diminished. It is known that hypoxia causes trans-differentiation of mesenchymal stem cells derived from bone marrow into adipocytes. However, it has not been elucidated yet if hypoxia turned myoblasts into adipocytes. We investigated adipogenesis in C2C12 and G8 murine myogenic cell line treated by hypoxia. Cells were also treated with the cocktail of insulin, dexamethasone and IBMX (MDI), which has been known to inhibit Wnt signaling and promote adipogenesis. Adipogenic differentiation was seen in both hypoxia and MDI. Adipogenic marker gene expression was assessed in C2C12. CCAAT/enhancer-binding protein (C/EBP) beta, alpha and peroxisome proliferator activating receptor (PPAR) gamma were increased by both hypoxia and MDI. The expression profile of Wnt10b was different between hypoxia and MDI. The mechanism for adipogenesis of myoblasts in hypoxia might be regulated by different mechanism than the modification of Wnt signaling.
authors.affiliation: Tohoku University School of Medicine, Sendai, Japan.
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Itoigawa
authors.forename: Koshi N
authors.initials: KN
authors.lastname: Kishimoto
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Okuno
authors.forename: Hirotaka
authors.initials: H
authors.lastname: Sano
authors.forename: Kazuo
authors.initials: K
authors.lastname: Kaneko
authors.forename: Eiji
authors.initials: E
authors.lastname: Itoi
mesh_terms: D015056:1-Methyl-3-isobutylxanthine / Q000494:pharmacology; D017667:Adipocytes / Q000378:metabolism / Q000473:pathology*; D050156:Adipogenesis; D000818:Animals; D022763:CCAAT-Enhancer-Binding Protein-alpha / Q000378:metabolism; D022782:CCAAT-Enhancer-Binding Protein-beta / Q000378:metabolism; D002460:Cell Line; D003907:Dexamethasone / Q000494:pharmacology; D005786:Gene Expression Regulation; D000860:Hypoxia / Q000378:metabolism / Q000473:pathology*; D007328:Insulin / Q000494:pharmacology; D051379:Mice; D009133:Muscular Atrophy / Q000378:metabolism / Q000473:pathology*; D032446:Myoblasts / Q000187:drug effects / Q000378:metabolism / Q000473:pathology*; D009419:Nerve Tissue Proteins / Q000235:genetics; D047495:PPAR gamma / Q000378:metabolism; D051153:Wnt Proteins / Q000235:genetics
chemical_list: D022763:CCAAT-Enhancer-Binding Protein-alpha; D022782:CCAAT-Enhancer-Binding Protein-beta; D007328:Insulin; D009419:Nerve Tissue Proteins; D047495:PPAR gamma; D051153:Wnt Proteins; C484143:Wnt10a protein, mouse; D003907:Dexamethasone; D015056:1-Methyl-3-isobutylxanthine