Differential roles of PKCα and PKCε in controlling the gene expression of Nox4 in human endothelial cells
Differential roles of PKCα and PKCε in controlling the gene expression of Nox4 in human endothelial cells
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DOI：
10.1016/j.freeradbiomed.2008.01.023
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发表时间：
2008-04-15
影响因子：
7.4
通讯作者：
Li, Huige
中科院分区：
文献类型：
--
作者：
Xu, Hui;Goettsch, Claudia;Li, Huige
NADPH氧化酶是血管壁中超氧化物的主要来源。本研究探讨蛋白激酶C（PKC）在调控NADPH氧化酶基因表达中的作用。用佛波醇12-肉豆蔻酸酯13-乙酸酯（PMA）或佛波醇12，13-二丁酸酯处理人脐静脉内皮细胞（HUVEC）和HUVEC衍生的EA.hy 926内皮细胞导致gp 91 phox同源物Nox 4的PKC依赖性双相表达。在佛波酯处理后6 h观察到Nox 4的下调，48 h观察到Nox 4的上调。早期Nox 4下调与减少超氧化物的产生，而后期Nox 4上调伴随着超氧化物的明显增强。PMA激活HUVEC和EA.hy926细胞中PKC亚型a和e。通过siRNA敲低PKC α阻止了Nox 4的早期下调，而敲低PKC α选择性地消除了Nox 4的晚期上调。血管内皮生长因子（VEGF），激活PKC α，但不激活PKC β在HUVEC，增加Nox 4的表达没有初始下调。VEGF诱导的Nox 4上调与HUVEC增殖和血管生成增强有关。抑制NADPH氧化酶可降低这两种效应。因此，PKC α的选择性抑制/敲低可能代表血管疾病的新治疗策略。(c)2008年爱思唯尔公司All rights reserved.
NADPH oxidases are major sources of superoxide in the vascular wall. This study investigates the role of protein kinase C (PKC) in regulating gene expression of NADPH oxidases. Treatment of human umbilical vein endothelial cells (HUVEC) and HUVEC-derived EA.hy 926 endothelial cells with phorbol 12-myristate 13-acetate (PMA) or phorbol 12,13-dibutyrate led to a PKC-dependent biphasic expression of the gp91phox homolog Nox4. A downregulation of Nox4 was observed at 6 h and an upregulation at 48 h after phorbol ester treatment. The early Nox4 downregulation was associated with a reduced superoxide production, whereas the late Nox4 upregulation was accompanied by a clear enhancement of superoxide. PMA activated the PKC isoforms a and e in HUVEC and EA.hy 926 cells. Knockdown of PKC epsilon by siRNA prevented the early downregulation of Nox4, whereas knockdown of PKC alpha selectively abolished the late Nox4 upregulation. Vascular endothelial growth factor (VEGF), which activates PKC alpha but not PKC epsilon in HUVEC, increased Nox4 expression without the initial downregulation. VEGF-induced Nox4 upregulation was associated with an enhanced proliferation and angiogenesis of HUVEC. Both effects could be reduced by inhibition of NADPH oxidase. Thus, a selective inhibition/knockdown of PKC alpha may represent a novel therapeutic strategy for vascular disease. (c) 2008 Elsevier Inc. All rights reserved.