title: Prostaglandin E2 stimulates bone sialoprotein (BSP) expression through cAMP and fibroblast growth factor 2 response elements in the proximal promoter of the rat BSP gene.
abstract: Bone sialoprotein (BSP), an early marker of osteoblast differentiation, has been implicated in the nucleation of hydroxyapatite during de novo bone formation. Prostaglandin E2 (PGE2) has anabolic effects on proliferation and differentiation of osteoblasts via diverse signal transduction systems. Because PGE2 increases the proportion of functional osteoblasts in fetal rat calvarial cell cultures, we investigated the regulation of BSP, as an osteoblastic marker, by PGE2. Treatment of rat osteosarcoma UMR 106 cells with 3 microm, 300 nm, and 30 nm PGE2 increased the steady state levels of BSP mRNA about 2.7-, 2.5-, and 2.4-fold after 12 h. From transient transfection assays, the constructs including the promoter sequence of nucleotides (nt) -116 to +60 (pLUC3) were found to enhance transcriptional activity 3.8- and 2.2-fold treated with 3 microm and 30 nm PGE2 for 12 h. 2-bp mutations were made in an inverted CCAAT box (between nt -50 and -46), a cAMP response element (CRE; between nt -75 and -68), a fibroblast growth factor 2 response element (FRE; nt -92 to -85), and a pituitary-specific transcription factor-1 motif (between nt -111 and -105) within pLUC3 and pLUC7 constructs. Transcriptional stimulation by PGE2 was almost completed abrogated in constructs that included 2-bp mutations in either the CRE and FRE. In gel shift analyses an increased binding of nuclear extract components to double-stranded oligonucleotide probes containing CRE and FRE was observed following treatment with PGE2. These studies show that PGE2 induces BSP transcription in UMR 106 cells through juxtaposed CRE and FRE elements in the proximal promoter of the BSP gene.
authors.affiliation: Periodontology, Endodontics, Pharmacology, Physiology, and Research Institute of Oral Science, Nihon University School of Dentistry at Matsudo, Chiba, 271-8587, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Samoto
authors.forename: Emi
authors.initials: E
authors.lastname: Shimizu
authors.forename: Yuko
authors.initials: Y
authors.lastname: Matsuda-Honjyo
authors.forename: Ryoichiro
authors.initials: R
authors.lastname: Saito
authors.forename: Sumi
authors.initials: S
authors.lastname: Nakao
authors.forename: Muneyoshi
authors.initials: M
authors.lastname: Yamazaki
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Furuyama
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Sugiya
authors.forename: Jaro
authors.initials: J
authors.lastname: Sodek
authors.forename: Yorimasa
authors.initials: Y
authors.lastname: Ogata
mesh_terms: D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D005576:Colforsin / Q000494:pharmacology; D017362:Cyclic AMP Response Element-Binding Protein / Q000187:drug effects* / Q000235:genetics / Q000502:physiology; D015232:Dinoprostone / Q000494:pharmacology*; D024202:Electrophoretic Mobility Shift Assay; D016222:Fibroblast Growth Factor 2 / Q000494:pharmacology*; D017353:Gene Deletion; D015870:Gene Expression / Q000187:drug effects*; D058574:Integrin-Binding Sialoprotein; D008156:Luciferases / Q000235:genetics; D016297:Mutagenesis, Site-Directed; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D011993:Recombinant Fusion Proteins; D020218:Response Elements / Q000187:drug effects* / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012795:Sialoglycoproteins / Q000235:genetics*; D014158:Transcription, Genetic / Q000187:drug effects; D014162:Transfection
chemical_list: D017362:Cyclic AMP Response Element-Binding Protein; C546873:Ibsp protein, rat; D058574:Integrin-Binding Sialoprotein; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; D012795:Sialoglycoproteins; D016222:Fibroblast Growth Factor 2; D005576:Colforsin; D008156:Luciferases; D015232:Dinoprostone