Induction of early response genes by hypergravity in cultured mouse osteoblastic cells (MC3T3-E1).
Hypergravity as low as 50g transiently stimulated cultured mouse osteoblastic cells (MC3T3-E1) to induce early response genes such as c-fos and egr-1, whereas expression of c-jun was marginally affected. The maximum induction of c-fos required more than 90g, but egr-1 induction became maximum below 50g. Staurosporin inhibited the induction of c-fos by hypergravity almost completely at a concentration of 0.1 microM, but it inhibited the induction of egr-1 only partially. In cells pretreated with 12-O-tetradecanoylphorbol 13-acetate, induction of c-fos by hypergravity was almost completely abolished, whereas that of egr-1 was not affected. Activity of protein kinase C seemed to be activated in cells centrifuged at 900g. These results indicate that hypergravity stimulates multiple signal transduction cascades that are connected with the expression of early response genes.
Nose
K
K
Department of Microbiology, Showa University School of Pharmaceutical Sciences, Tokyo, Japan.
Shibanuma
M
M
D000818:Animals; D015152:Blotting, Northern; D002460:Cell Line; D004268:DNA-Binding Proteins / Q000032:analysis / Q000235:genetics; D051766:Early Growth Response Protein 1; D005786:Gene Expression Regulation / Q000235:genetics*; D017781:Genes, Immediate-Early / Q000235:genetics*; D016762:Genes, fos / Q000235:genetics; D016758:Genes, jun / Q000235:genetics; D006112:Gravitation; D017874:Immediate-Early Proteins; D051379:Mice; D010006:Osteoblasts / Q000737:chemistry / Q000166:cytology*; D016760:Proto-Oncogene Proteins c-fos / Q000032:analysis / Q000235:genetics; D016755:Proto-Oncogene Proteins c-jun / Q000032:analysis / Q000235:genetics; D012313:RNA / Q000032:analysis / Q000235:genetics; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014157:Transcription Factors / Q000032:analysis / Q000235:genetics
D004268:DNA-Binding Proteins; D051766:Early Growth Response Protein 1; C486109:Egr1 protein, mouse; D017874:Immediate-Early Proteins; D016760:Proto-Oncogene Proteins c-fos; D016755:Proto-Oncogene Proteins c-jun; D014157:Transcription Factors; D012313:RNA; D013755:Tetradecanoylphorbol Acetate