title: Transcriptional regulation of the human bone sialoprotein gene by fibroblast growth factor 2.
abstract: Fibroblast growth factor 2 (FGF2), a member of the FGF family, positively regulates bone formation and osteoblast differentiation. Bone sialoprotein (BSP) is highly expressed during early bone formation and may play a role in primary mineralization of bone. In the present study, FGF2 (10 ng/mL) was found to increase the levels of Runx2 and BSP mRNA at 3 and 12 h in human osteoblast-like Saos2 cells. Transient transfection assays were performed using chimeric constructs of the human BSP gene promoter ligated with a luciferase reporter gene. FGF2 (10 ng/mL, 12 h) induced the luciferase activities of the -84LUC and -927LUC constructs in Saos2 cells. The results of gel shift assays showed that FGF2 (10 ng/mL) increased the binding of nuclear protein to the FGF2 response element (FRE) and the activator protein 1 (AP1) binding site. Antibodies against Dlx5, Msx2, Runx2 and Smad1 blocked FRE-protein complex formation, and antibodies against CREB1, c-Jun and Fra2 interrupted AP1-protein complex formation. These results indicate that FGF2 increases BSP transcription by targeting the FRE and AP1 elements in the proximal promoter of the human BSP gene. Moreover, the transcription factors Dlx5, Msx2, Runx2, Smad1, CREB1, c-Jun and Fra2 could be key regulators of the effects of FGF2 on human BSP transcription.
authors.affiliation: Department of Periodontology, Nihon University School of Dentistry at Matsudo, Matsudo, Japan.
authors.forename: Liming
authors.initials: L
authors.lastname: Zhou
authors.forename: Yorimasa
authors.initials: Y
authors.lastname: Ogata
mesh_terms: D018929:Cell Culture Techniques; D002460:Cell Line; D002678:Chimera / Q000235:genetics; D050659:Core Binding Factor Alpha 1 Subunit / Q000235:genetics; D017362:Cyclic AMP Response Element-Binding Protein / Q000235:genetics; D016222:Fibroblast Growth Factor 2 / Q000235:genetics*; D051921:Fos-Related Antigen-2 / Q000235:genetics; D005786:Gene Expression Regulation / Q000235:genetics; D016758:Genes, jun / Q000235:genetics; D018398:Homeodomain Proteins / Q000235:genetics; D006801:Humans; D058574:Integrin-Binding Sialoprotein / Q000235:genetics*; D008156:Luciferases; D049408:Luminescent Agents; D010006:Osteoblasts / Q000378:metabolism; D011401:Promoter Regions, Genetic / Q000235:genetics; D020218:Response Elements / Q000235:genetics; D051898:Smad1 Protein / Q000235:genetics; D013997:Time Factors; D018808:Transcription Factor AP-1 / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics; D014158:Transcription, Genetic / Q000235:genetics*; D014162:Transfection
chemical_list: C115163:CREB1 protein, human; D050659:Core Binding Factor Alpha 1 Subunit; D017362:Cyclic AMP Response Element-Binding Protein; C100596:DLX5 protein, human; C497872:FOSL2 protein, human; D051921:Fos-Related Antigen-2; D018398:Homeodomain Proteins; D058574:Integrin-Binding Sialoprotein; D049408:Luminescent Agents; C084119:MSX2 protein; C493709:RUNX2 protein, human; C497399:SMAD1 protein, human; D051898:Smad1 Protein; D018808:Transcription Factor AP-1; D014157:Transcription Factors; D016222:Fibroblast Growth Factor 2; D008156:Luciferases