title: Possible involvement of phosphatidylinositol 3-kinase/Akt pathway in insulin-like growth factor-I-induced alkaline phosphatase activity in osteoblasts.
abstract: In the present study, we investigated whether Akt is involved in insulin-like growth factor-I (IGF-I)-stimulated activity of alkaline phosphatase, a marker of mature osteoblast phenotype, in osteoblast-like MC3T3-E1 cells. IGF-I induced the phosphorylation of Akt in these cells. Akt inhibitor significantly suppressed the IGF-I-stimulated alkaline phosphatase activity. The phosphorylation of Akt induced by IGF-I was reduced by the Akt inhibitor. LY294002 and wortmannin, inhibitors of phosphatidylinositol 3-kinase, significantly suppressed the IGF-I-induced alkaline phosphatase activity. The phosphorylation of Akt induced by IGF-I was markedly reduced by LY294002 and wortmannin. These results strongly suggest that phosphatidylinositol 3-kinase/Akt plays a role in the IGF-I-stimulated alkaline phosphatase activity in osteoblasts.
authors.affiliation: Department of Pharmacology, Gifu University Graduate School of Medicine, Gifu, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Noda
authors.forename: H
authors.initials: H
authors.lastname: Tokuda
authors.forename: M
authors.initials: M
authors.lastname: Yoshida
authors.forename: E
authors.initials: E
authors.lastname: Yasuda
authors.forename: Y
authors.initials: Y
authors.lastname: Hanai
authors.forename: S
authors.initials: S
authors.lastname: Takai
authors.forename: O
authors.initials: O
authors.lastname: Kozawa
mesh_terms: D000469:Alkaline Phosphatase / Q000096:biosynthesis*; D000818:Animals; D002999:Clone Cells; D007334:Insulin-Like Growth Factor I / Q000494:pharmacology*; D051379:Mice; D010006:Osteoblasts / Q000201:enzymology*; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt; D015398:Signal Transduction / Q000187:drug effects* / Q000502:physiology
chemical_list: D000469:Alkaline Phosphatase; D007334:Insulin-Like Growth Factor I; D019869:Phosphatidylinositol 3-Kinases; D017346:Protein Serine-Threonine Kinases; D011518:Proto-Oncogene Proteins; D051057:Proto-Oncogene Proteins c-akt