title: Competition between c-fos and 1,25(OH)2 vitamin D3 in the transcriptional control of type I collagen synthesis in MC3T3-E1 osteoblastic cells.
abstract: Interaction between c-fos and 1,25(OH)2 vitamin D3 (VD) on the type I collagen synthesis was studied. VD inhibited collagen synthesis and type I collagen mRNA expression in MC3T3-E1 osteoblastic cells. In contrast, VD reversed the inhibition of collagen synthesis and mRNA expression of the c-fos transfectants that overexpressed c-fos gene to a comparable level as those of the control transfectants. The gel shift assay showed the vitamin D receptor (VDR) complex binding to vitamin D responsive element (VDRE) was inhibited under constitutively expressed c-fos gene, suggesting that c-fos gene product, c-Fos, may inhibit the binding of VDR complex to VDRE by making a c-Fos-VDR complex. The result suggests the existence of a fine tuning between c-fos and VD in the bone metabolism which may be relevant to the pathogenesis of rheumatoid bone lesion.
authors.affiliation: Department of Medicine, Kobe University School of Medicine, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Kuroki
authors.forename: S
authors.initials: S
authors.lastname: Shiozawa
authors.forename: J
authors.initials: J
authors.lastname: Kano
authors.forename: K
authors.initials: K
authors.lastname: Chihara
mesh_terms: D016475:3T3 Cells; D000818:Animals; D001483:Base Sequence; D001667:Binding, Competitive; D002117:Calcitriol / Q000502:physiology*; D003094:Collagen / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000378:metabolism; D005786:Gene Expression Regulation; D051379:Mice; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000378:metabolism; D009838:Oligodeoxyribonucleotides / Q000737:chemistry; D010006:Osteoblasts / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D016760:Proto-Oncogene Proteins c-fos / Q000502:physiology*; D012333:RNA, Messenger / Q000235:genetics; D018167:Receptors, Calcitriol / Q000502:physiology*; D018808:Transcription Factor AP-1 / Q000502:physiology*; D014158:Transcription, Genetic; D014162:Transfection
chemical_list: D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D009838:Oligodeoxyribonucleotides; D016760:Proto-Oncogene Proteins c-fos; D012333:RNA, Messenger; D018167:Receptors, Calcitriol; D018808:Transcription Factor AP-1; D003094:Collagen; D002117:Calcitriol