title: Increased adipogenicity of cells from regenerating skeletal muscle.
abstract: Adipose tissue development is observed in some muscle pathologies, however, mechanisms that induce accumulation of this tissue as well as its cellular origin are unknown. The adipogenicity of cells from bupivacaine hydrochloride (BPVC)-treated and untreated muscle was compared in vitro. Culturing cells from both BPVC-treated and untreated muscles in adipogenic differentiation medium (ADM) for 10 days resulted in the appearance of mature adipocytes, but their number was 3.5-fold higher in cells from BPVC-treated muscle. Temporal expressions of PPARgamma and the presence of lipid droplets during adipogenic differentiation were examined. On day 2 of culture in ADM, only cells from BPVC-treated muscle were positive both for PPARgamma and lipid droplets. Pref-1 was expressed in cells from untreated muscle, whereas its expression was absent in cells from BPVC-treated muscle. In ADM, the presence of insulin, which negates an inhibitory effect of Pref-1 on adipogenic differentiation, was required for PPARgamma2 expression in cells from untreated muscle, but not for cells from BPVC-treated muscle. These results indicate that BPVC-induced degenerative/regenerative changes in muscle lead to increased adipogenicity of cells, and suggest that this increased adipogenicity not only involves an increase in the number of cells having adipogenic potential, but also contributes to the progression of these cells toward adipogenic differentiation.
authors.affiliation: Department of Veterinary Physiology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan. akeita@mail.ecc.u-tokyo.ac.jp
authors.forename: Keitaro
authors.initials: K
authors.lastname: Yamanouchi
authors.forename: Erica
authors.initials: E
authors.lastname: Yada
authors.forename: Naomi
authors.initials: N
authors.lastname: Ishiguro
authors.forename: Tohru
authors.initials: T
authors.lastname: Hosoyama
authors.forename: Masugi
authors.initials: M
authors.lastname: Nishihara
mesh_terms: D017667:Adipocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D050156:Adipogenesis / Q000187:drug effects; D000818:Animals; D002045:Bupivacaine / Q000378:metabolism / Q000494:pharmacology; D022763:CCAAT-Enhancer-Binding Protein-alpha / Q000378:metabolism; D002454:Cell Differentiation; D002478:Cells, Cultured; D007150:Immunohistochemistry; D007328:Insulin / Q000378:metabolism; D008297:Male; D018482:Muscle, Skeletal / Q000187:drug effects / Q000502:physiology*; D017570:MyoD Protein / Q000378:metabolism; D047495:PPAR gamma / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D012038:Regeneration / Q000187:drug effects
chemical_list: D022763:CCAAT-Enhancer-Binding Protein-alpha; D007328:Insulin; D017570:MyoD Protein; C057363:MyoD1 myogenic differentiation protein; D047495:PPAR gamma; D002045:Bupivacaine