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Immediate and delayed VEGF‐mediated NO synthesis in endothelial cells: Role of PI3K, PKC and PLC pathways
Author(s) -
Gélinas David S,
Bernatchez Pascal N,
Rollin Simon,
Bazan Nicolas G,
Sirois Martin G
Publication year - 2002
Publication title -
british journal of pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.432
H-Index - 211
eISSN - 1476-5381
pISSN - 0007-1188
DOI - 10.1038/sj.bjp.0704956
Subject(s) - wortmannin , enos , protein kinase c , phospholipase c , phosphorylation , nitric oxide , ly294002 , microbiology and biotechnology , pi3k/akt/mtor pathway , chemistry , protein kinase b , signal transduction , medicine , endocrinology , biology , nitric oxide synthase
The mechanism(s) by which vascular endothelial growth factor (VEGF) induces endothelial nitric oxide synthase (eNOS) activation remain(s) unclear up to a certain extent. Therefore, we sought to evaluate the contribution of numerous pathways in VEGF‐induced nitric oxide (NO) synthesis by measuring cGMP production. In addition, as VEGF induces the synthesis of NO and platelet‐activating factor (PAF), we wanted to assess if the induction of PAF and NO is contributing to the synthesis of each other. Herein, we show that a treatment of endothelial cells with a phospholipase C (PLC) inhibitor (U73122), a calmodulin antagonist (W‐7) or with intracellular calcium chelators (EGTA/AM, BAPTA/AM) prevented VEGF‐mediated eNOS Ser 1177 ‐phosphorylation and NO synthesis measured by cGMP production. Pretreatment with phosphatidylinositol 3‐kinase (PI3K) (Wortmannin, LY294002) or protein kinase C (PKC) (GF109203X, Ro318220) inhibitors attenuated eNOS Ser 1177 ‐phosphorylation mediated by VEGF, but did not alter immediate (0–10 min) cGMP synthesis induced by VEGF, but abrogated by up to 84% the delayed (10–30 min) cGMP synthesis. Pretreatment with PAF synthesis inhibitors or with PAF receptor antagonists did not abrogate neither eNOS Ser 1177 ‐phosphorylation nor cGMP synthesis mediated by VEGF. In conclusion, VEGF induces an immediate cGMP synthesis through the PLC‐Ca 2+ /CaM pathway, and that the induction of delayed cGMP synthesis implies Akt and PKC activity.British Journal of Pharmacology (2002) 137 , 1021–1030. doi: 10.1038/sj.bjp.0704956