title: Effect of chlorpromazine on bone sialoprotein (BSP) gene transcription.
abstract: Bone sialoprotein (BSP), an early marker of osteoblast differentiation. Whereas physical forces may play an important role in the regulation of bone cell function, little is known about how cells are able to sense mechanical loads. Chlorpromazine, a tranquilizing agent for treatments of psychiatric disorders, mimics hypotonic stress and causes membrane deformation. Application of 10 microg/ml of chlorpromazine suppressed BSP mRNA levels after 12 and 24 h in osteoblast-like ROS17/2.8 cells and rat stromal bone marrow cells (SBMC-D8). Chlorpromazine (10 microg/ml) decreased luciferase activity of the construct (pLUC3; -116 to +60 of the rat BSP gene promoter) after 12 h, the effect was inhibited by the tyrosine kinase inhibitor herbimycin A (HA) and MAP kinase kinase inhibitor U0126. Introduction of 2-bp mutation in the pLUC3 construct showed that the chlorpromazine effects were mediated by cAMP response element (CRE) and FGF2 response element (FRE). In gel shift assays, using radiolabeled double-stranded CRE and FRE oligonucleotides, which revealed decreased binding of nuclear proteins from chlorpromazine-stimulated cells. These studies, therefore, show that chlorpromazine suppresses BSP gene transcription through tyrosine and MAP kinases-dependent pathways and that the chlorpromazine effects are mediated by CRE and FRE elements in the proximal promoter of the BSP gene.
authors.affiliation: Department of Periodontology, Nihon University School of Dentistry at Matsudo, Chiba 271-8587, Japan.
authors.forename: Yu
authors.initials: Y
authors.lastname: Nakajima
authors.forename: Naoko
authors.initials: N
authors.lastname: Kato
authors.forename: Youhei
authors.initials: Y
authors.lastname: Nakayama
authors.forename: Dong-Soon
authors.initials: DS
authors.lastname: Kim
authors.forename: Hideki
authors.initials: H
authors.lastname: Takai
authors.forename: Masato
authors.initials: M
authors.lastname: Arai
authors.forename: Ryoichiro
authors.initials: R
authors.lastname: Saito
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Samoto
authors.forename: Emi
authors.initials: E
authors.lastname: Shimizu
authors.forename: Yorimasa
authors.initials: Y
authors.lastname: Ogata
mesh_terms: D000818:Animals; D001483:Base Sequence; D001854:Bone Marrow Cells / Q000187:drug effects / Q000378:metabolism; D002460:Cell Line; D002746:Chlorpromazine / Q000378:metabolism / Q000494:pharmacology*; D024202:Electrophoretic Mobility Shift Assay; D058574:Integrin-Binding Sialoprotein; D008957:Models, Genetic; D008969:Molecular Sequence Data; D010006:Osteoblasts / Q000378:metabolism; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D020218:Response Elements; D012795:Sialoglycoproteins / Q000378:metabolism*; D014158:Transcription, Genetic / Q000187:drug effects*; D014162:Transfection
chemical_list: C546873:Ibsp protein, rat; D058574:Integrin-Binding Sialoprotein; D012333:RNA, Messenger; D012795:Sialoglycoproteins; D002746:Chlorpromazine