title: Effect of vitamin D3 on prostaglandin E2 synthesis in osteoblast-like cells.
abstract: We previously showed that prostaglandin (PG) F2 alpha stimulates PGE2 synthesis in osteoblast-like MC3T3-E1 cells, and that the activation of protein kinase C (PKC) amplifies the effect of PGF2 alpha through the potentiation of phospholipase A2 activity (H. Tokuda, Y. Oiso and O. Kozawa, J Cell Biochem. 48: 262-268, 1992). In the present study, we investigated the effects of vitamin D3 on PGF2 alpha-induced PGE2 synthesis in MC3T3-E1 cells. The pretreatment with 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3], an active form of vitamin D3, significantly inhibited the PGF2 alpha-induced PGE2 synthesis in a dose-dependent manner in the range between 1 pM and 1 nM. This inhibitory effect of 1,25-(OH)2D3 was dependent on the time of pretreatment up to 8 h. On the contrary, the pretreatment with 24,25-dihydroxyvitamin D3, an inactive form of vitamin D3, had little effect on the PGF2 alpha-induced PGE2 synthesis in these cells. However, the pretreatment with 1,25-(OH)2D3 no longer affected the amplification of PGF2 alpha-induced PGE2 synthesis by 12-O-tetradecanoylphorbol-13-acetate, a PKC activator. These results strongly suggest that 1,25-(OH)2D3 inhibits PGF2 alpha-induced PGE2 synthesis in osteoblast-like cells, however, the activation of PKC reverses this inhibitory effect of 1,25-(OH)2D3.
authors.affiliation: First Department of Internal Medicine, Nagoya University School of Medicine, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Suzuki
authors.forename: H
authors.initials: H
authors.lastname: Tokuda
authors.forename: J
authors.initials: J
authors.lastname: Kotoyori
authors.forename: Y
authors.initials: Y
authors.lastname: Ito
authors.forename: Y
authors.initials: Y
authors.lastname: Oiso
authors.forename: O
authors.initials: O
authors.lastname: Kozawa
mesh_terms: D015650:24,25-Dihydroxyvitamin D 3 / Q000494:pharmacology; D000818:Animals; D002117:Calcitriol / Q000494:pharmacology; D002460:Cell Line; D002762:Cholecalciferol / Q000494:pharmacology*; D015237:Dinoprost / Q000494:pharmacology; D015232:Dinoprostone / Q000096:biosynthesis*; D004789:Enzyme Activation / Q000187:drug effects; D051379:Mice; D010006:Osteoblasts / Q000187:drug effects* / Q000378:metabolism*; D011493:Protein Kinase C / Q000378:metabolism; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
chemical_list: D002762:Cholecalciferol; D015650:24,25-Dihydroxyvitamin D 3; D015237:Dinoprost; D011493:Protein Kinase C; D002117:Calcitriol; D015232:Dinoprostone; D013755:Tetradecanoylphorbol Acetate