Stimulatory effect of basic fibroblast growth factor on induction of heat shock protein 27 in osteoblasts: role of protein kinase C.
In a previous study we showed that basic fibroblast growth factor (bFGF) stimulates activation of protein kinase C through phosphoinositide hydrolysis by phospholipase C and phosphatidylcholine hydrolysis by phospholipase D in osteoblast-like MC3T3-E1 cells. In the present study, we investigated whether bFGF stimulates the induction of heat shock protein (HSP) 27, a low-molecular-weight HSP, and HSP70, a high-molecular-weight HSP, in MC3T3-E1 cells and the mechanism behind the induction. bFGF increased the level of HSP27 while having little effect on HSP70 level. bFGF stimulated the accumulation of HSP27 dose-dependently in the range between 1 and 30 ng/ml. bFGF induced an increase in the level of the mRNA for HSP27. The bFGF-stimulated accumulation of HSP27 was reduced by inhibitors of protein kinase C. The bFGF-induced HSP27 accumulation was reduced in protein kinase C-downregulated MC3T3-E1 cells. U-73122, an inhibitor of phospholipase C, and propranolol, a phosphatidic acid phosphohydrolase inhibitor, suppressed the bFGF-stimulated HSP27 accumulation. These results strongly suggest that bFGF stimulates HSP27 induction through protein kinase C activation in osteoblasts.
Kozawa
O
O
Department of Pharmacology, Gifu University School of Medicine, Japan. okozawa@cc.gifu-u.ac.jp
Niwa
M
M
Matsuno
H
H
Ishisaki
A
A
Kato
K
K
Uematsu
T
T
D016475:3T3 Cells; D000818:Animals; D015152:Blotting, Northern; D002352:Carrier Proteins / Q000494:pharmacology; D015536:Down-Regulation; D004347:Drug Interactions; D004963:Estrenes / Q000494:pharmacology; D016222:Fibroblast Growth Factor 2 / Q000494:pharmacology*; D018840:HSP70 Heat-Shock Proteins / Q000096:biosynthesis; D006360:Heat-Shock Proteins; D047908:Intracellular Signaling Peptides and Proteins; D051379:Mice; D018832:Molecular Chaperones; D009363:Neoplasm Proteins / Q000096:biosynthesis*; D010006:Osteoblasts / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology; D011433:Propranolol / Q000494:pharmacology; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000378:metabolism / Q000502:physiology*; D011760:Pyrrolidinones / Q000494:pharmacology; D012333:RNA, Messenger / Q000096:biosynthesis / Q000187:drug effects
D002352:Carrier Proteins; D004963:Estrenes; D018840:HSP70 Heat-Shock Proteins; D006360:Heat-Shock Proteins; C486113:Hsbp1 protein, mouse; D047908:Intracellular Signaling Peptides and Proteins; D018832:Molecular Chaperones; D009363:Neoplasm Proteins; D010726:Phosphodiesterase Inhibitors; D011760:Pyrrolidinones; D012333:RNA, Messenger; C015482:protein kinase modulator; D016222:Fibroblast Growth Factor 2; C060229:1-(6-((3-methoxyestra-1,3,5(10)-trien-17-yl)amino)hexyl)-1H-pyrrole-2,5-dione; D011433:Propranolol; D011493:Protein Kinase C