title: Protein kinase C inhibitors enhance differentiation of rat adipocyte precursor cells in serum-free culture.
abstract: The involvement of protein kinase C in differentiation of rat adipocyte precursor cells in serum-free culture was evaluated by using various protein kinase inhibitors. Induction of adipose conversion, which was maximal after 10 days of culture in the presence of 5 micrograms/ml insulin, 10 micrograms/ml transferrin, and 200 pM triiodothyronine, was inhibited by the addition of protein kinase C inhibitors, H-7 and staurosporine, in a dose-dependent fashion with the maximal effect at 10 microM and 10 nM, respectively. Inhibition of adipocyte differentiation by 12-O-tetradecanoylphorbol 13-acetate (10(-8) M), an activator of protein kinase C, was reversed by a concomitant addition of either 10 microM H-7 or 10 nM staurosporine. HA1004, a potent inhibitor of cAMP- and cGMP-dependent protein kinases, with minimal inhibitory activity on protein kinase C, did not affect adipose conversion. Furthermore, H-89, another isoquinoline derivative with a selective inhibitory action on cAMP-dependent protein kinase, was without effect on cellular differentiation. These results indicate that the potentiation of adipogenesis by H-7 and staurosporine is mediated by suppression of protein kinase C and that protein kinase C is involved in adipocyte differentiation in an inhibitory fashion.
authors.affiliation: Department of Pediatrics, Tokai University School of Medicine, Kanagawa-ken, Japan.
authors.forename: O
authors.initials: O
authors.lastname: Shinohara
authors.forename: Y
authors.initials: Y
authors.lastname: Murata
authors.forename: C
authors.initials: C
authors.lastname: Kubota
authors.forename: T
authors.initials: T
authors.lastname: Shinagawa
mesh_terms: D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; D000273:Adipose Tissue / Q000166:cytology* / Q000187:drug effects / Q000502:physiology; D000470:Alkaloids / Q000494:pharmacology; D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects; D002478:Cells, Cultured; D016895:Culture Media, Serum-Free; D005993:Glycerolphosphate Dehydrogenase / Q000032:analysis; D007546:Isoquinolines / Q000494:pharmacology; D008297:Male; D010879:Piperazines / Q000494:pharmacology; D011493:Protein Kinase C / Q000037:antagonists & inhibitors*; D051381:Rats; D019311:Staurosporine; D013449:Sulfonamides; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
chemical_list: D000470:Alkaloids; D016895:Culture Media, Serum-Free; D007546:Isoquinolines; D010879:Piperazines; D013449:Sulfonamides; D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; C043204:N-(2-guanidinoethyl)-5-isoquinolinesulfonamide; D005993:Glycerolphosphate Dehydrogenase; D011493:Protein Kinase C; D019311:Staurosporine; C063509:N-(2-(4-bromocinnamylamino)ethyl)-5-isoquinolinesulfonamide; D013755:Tetradecanoylphorbol Acetate