Basic fibroblast growth factor stimulates phosphatidylcholine-hydrolyzing phospholipase D in osteoblast-like cells.
We examined the effect of basic fibroblast growth factor (bFGF) on the activation of phosphatidylcholine-hydrolyzing phospholipase D in osteoblast-like MC3T3-E1 cells. bFGF stimulated both the formations of choline (EC50 was 30 ng/ml) and inositol phosphates (EC50 was 10 ng/ml). Calphostin C, an inhibitor of protein kinase C (PKC), had little effect on the bFGF-induced formation of choline. bFGF stimulated the formation of choline also in PKC down regulated cells. Genistein and methyl 2,5-dihydroxycinnamate, inhibitors of protein tyrosine kinases, significantly suppressed the bFGF-induced formation of choline. Sodium orthovanadate, an inhibitor of protein tyrosine phosphatases, enhanced the bFGF-induced formation of choline. In vitro kinase assay for FGF receptors revealed that FGF receptor 1 and 2 were autophosphorylated after FGF stimulation. bFGF dose-dependently stimulated DNA synthesis of these cells. These results strongly suggest that bFGF activates phosphatidylcholine-hydrolyzing phospholipase D through the activation of tyrosine kinase, but independently of PKC activated by phosphoinositide hydrolysis in osteoblast-like cells.
Suzuki
A
A
First Department of Internal Medicine, Nagoya University, School of Medicine, Japan.
Shinoda
J
J
Kanda
S
S
Oiso
Y
Y
Kozawa
O
O
D000818:Animals; D002934:Cinnamates / Q000494:pharmacology; D004247:DNA / Q000096:biosynthesis; D015536:Down-Regulation; D004591:Electrophoresis, Polyacrylamide Gel; D004791:Enzyme Inhibitors / Q000494:pharmacology; D016222:Fibroblast Growth Factor 2 / Q000494:pharmacology*; D019833:Genistein; D007295:Inositol Phosphates / Q000378:metabolism; D007529:Isoflavones / Q000494:pharmacology; D051379:Mice; D009281:Naphthalenes / Q000494:pharmacology; D010006:Osteoblasts / Q000201:enzymology*; D010713:Phosphatidylcholines / Q000378:metabolism*; D010739:Phospholipase D / Q000378:metabolism*; D010766:Phosphorylation; D010767:Phosphorylcholine / Q000378:metabolism; D011233:Precipitin Tests; D011493:Protein Kinase C / Q000378:metabolism; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D017468:Receptors, Fibroblast Growth Factor / Q000032:analysis / Q000276:immunology / Q000378:metabolism; D014638:Vanadates / Q000494:pharmacology
D002934:Cinnamates; D004791:Enzyme Inhibitors; D007295:Inositol Phosphates; D007529:Isoflavones; D009281:Naphthalenes; D010713:Phosphatidylcholines; D017468:Receptors, Fibroblast Growth Factor; D016222:Fibroblast Growth Factor 2; D010767:Phosphorylcholine; D014638:Vanadates; C067472:methyl 2,5-dihydroxycinnamate; D004247:DNA; D019833:Genistein; D011505:Protein-Tyrosine Kinases; D011493:Protein Kinase C; D010739:Phospholipase D; C058819:calphostin C