Immediate and delayed VEGF-mediated NO synthesis in endothelial cells:: Role of PI3K, PKC and PLC pathways
Immediate and delayed VEGF-mediated NO synthesis in endothelial cells:: Role of PI3K, PKC and PLC pathways
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DOI：
10.1038/sj.bjp.0704956
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发表时间：
2002-12-01
影响因子：
7.3
通讯作者：
Sirois, MG
中科院分区：
文献类型：
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作者：
Gélinas, DS;Bernatchez, PN;Sirois, MG
1血管内皮生长因子（VEGF）诱导内皮型一氧化氮合酶（eNOS）激活的机制在一定程度上仍不清楚。因此，我们试图通过测量cGMP的产生来评估VEGF诱导的一氧化氮（NO）合成中许多途径的贡献。此外，由于VEGF诱导NO和血小板活化因子（PAF）的合成，我们希望评估PAF和NO的诱导是否有助于彼此的合成。2在此，我们表明用磷脂酶C（PLC）抑制剂（U 73122）、钙调蛋白拮抗剂（W-7）或细胞内钙螯合剂处理内皮细胞，（EGTA/AM，BAPTA/AM）阻止VEGF介导的eNOS Ser（1117）-磷酸化和NO合成（通过cGMP产生测量）。（渥曼青霉素，LY 294002）或蛋白激酶C（PKC）（GF109203）（，Ro 318220）抑制剂减弱VEGF介导的eNOS Ser（1117）-磷酸化，但并没有立即改变（0 - 10分钟）VEGF诱导的cGMP合成，但废除了高达84%的延迟（10-30分钟）cGMP合成。4用PAF合成抑制剂或PAF受体拮抗剂预处理既不消除eNOS Ser（1177）-5总之，VEGF通过PLC-Ca 2 +/CaM途径诱导即时cGMP合成，并且延迟cGMP合成的诱导暗示Akt和PKC活性。
1 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.2 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(1117)-phosphorylation and NO synthesis measured by cGMP production.3 Pretreatment with phosphatidylinositol 3-kinase (PI3K) (Wortmannin, LY294002) or protein kinase C (PKC) (GF109203)(, Ro318220) inhibitors attenuated eNOS Ser(1117)-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.4 Pretreatment with PAF synthesis inhibitors or with PAF receptor antagonists did not abrogate neither eNOS Ser(1177)-phosphorylation nor cGMP synthesis mediated by VEGF.5 In conclusion, VEGF induces an immediate cGMP synthesis through the PLC-Ca2+/CaM pathway, and that the induction of delayed cGMP synthesis implies Akt and PKC activity.