The effect of insulin-like growth factor-I on production of vascular endothelial growth factor by amnion-derived (WISH) cells.
OBJECTIVE
Our objective was to clarify the modulation of vascular endothelial growth factor (VEGF) by amniotic cells.


METHODS
Amnion-derived (WISH) cells were cultured, and the effect of insulin-like growth factor (IGF), mitogen-activated protein (MAP) kinase kinase and/or extracellular signal-regulated kinase (ERK) kinase (MEK) inhibitors (U0126), and phosphatidylinositol (PI) 3-kinase inhibitors (wortmannin) on the production of VEGF was examined. VEGF was assayed using ELISA. The activations of MAP kinase and akt, which is phosphorylated by PI 3-kinase, were detected by Western blot analysis using anti-phosphorylated MAP kinase antibody and anti-phosphorylated akt antibody.


RESULTS
In the time course of VEGF production following IGF-I treatment, VEGF production showed significant increases only at 16 and 32 h (p < 0.01). Also, IGF-I increased the production of VEGF by WISH cells in a dose-dependent manner. The MAP kinase and akt activities were recognized by treatment with IGF-I and suppressed by U0126 and wortmannin, respectively. When WISH cells were pretreated for 2 h with U0126 and wortmannin and then treated with IGF-I for 16 h, the production of VEGF was significantly decreased in a dose-dependent manner (p < 0.01, p < 0.01, respectively).


CONCLUSIONS
WISH cells appeared to produce VEGF via a mechanism involving tyrosine kinase interaction with IGF-I receptor, resulting in MAP kinase and PI 3-kinase activation. It is suggested that VEGF may contribute to the neovascularization and proliferation of the placenta and gestational tissue, and IGF-I may play an important role in the modulation of VEGF production in the placenta.
Kawano
Yasushi
Y
Department of Obstetrics and Gynecology, Faculty of Medicine, Oita University, Idaigaoka 1-1, Hasama-machi, Oita, Japan. kawayas@med.oita-u.ac.jp
Nakamura
Satomi
S
Fukuda
Junichiro
J
Miyakawa
Isao
I
D000650:Amnion / Q000166:cytology / Q000201:enzymology*; D002478:Cells, Cultured; D004791:Enzyme Inhibitors / Q000378:metabolism; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000494:pharmacology / Q000502:physiology*; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D042461:Vascular Endothelial Growth Factor A / Q000037:antagonists & inhibitors / Q000096:biosynthesis*
D004791:Enzyme Inhibitors; D042461:Vascular Endothelial Growth Factor A; D007334:Insulin-Like Growth Factor I; D019869:Phosphatidylinositol 3-Kinases; D020928:Mitogen-Activated Protein Kinases