Endothelium-dependent coronary vasodilatation requires NADPH oxidase-derived reactive oxygen species.
Endothelium-dependent coronary vasodilatation requires NADPH oxidase-derived reactive oxygen species.
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DOI：
10.1161/atvbaha.110.209726
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发表时间：
2010-09
期刊：
影响因子：
--
通讯作者：
Abid MR
中科院分区：
文献类型：
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作者：
Feng J;Damrauer SM;Lee M;Sellke FW;Ferran C;Abid MR
内皮源性一氧化氮（NO）对于调节冠状血管张力很重要。过量的活性氧 (ROS) 已被证明会降低一氧化氮的生物利用度，导致内皮功能障碍和冠状动脉疾病。然而，生理ROS水平在NO介导的冠状血管舒张中的功能意义尚不清楚。 NADPH 氧化酶是内皮细胞 (EC) 中 ROS 的主要来源。本研究的目的是确定 NADPH 氧化酶衍生的内源 ROS 减少对完整冠状血管血管张力的影响。使用基于光泽精的超氧化物产生和 DCFH-DA FACS 测定，我们发现与 WT MHEC 相比，来自 NADPH 氧化酶敲低 (p47phox−/−) 动物的小鼠心脏 EC (MHEC) 降低了 NADPH 氧化酶活性（降低了 >40%）和 ROS 水平（降低了 >30%）。令人惊讶的是，在p47phox−/−动物中，ROS的减少并没有改善冠状血管舒缩，而是内皮依赖性VEGF介导的冠状血管舒张减少了>50%。蛋白质印迹和 L-瓜氨酸测定显示 p47phox−/− 冠状血管和 MHEC 中的 Akt 和 eNOS 磷酸化以及 NO 合成分别显着减少。 p47phox−/− 中组成型活性 eNOS 的腺病毒表达恢复了 VEGF 介导的冠状血管舒张。这些数据表明，内皮依赖性 VEGF 对冠状血管张力的调节需要 NADPH 氧化酶衍生的 ROS 来激活 PI3K-Akt-eNOS 轴。
Endothelium-derived nitric oxide (NO) is important in regulating coronary vascular tone. Excess reactive oxygen species (ROS) have been shown to reduce NO bioavailability resulting in endothelial dysfunction and coronary diseases. However, the functional significance of physiological ROS levels in NO-mediated coronary vasodilatation is not known. NADPH oxidase is a major source of ROS in endothelial cells (ECs). The aim of this study was to determine the effects of reduction in NADPH oxidase-derived endogenous ROS on vascular tone in intact coronary blood vessels. Using lucigenin-based superoxide production and DCFH-DA FACS assays, we found that mouse heart ECs (MHEC) from NADPH oxidase-knockdown (p47phox−/−) animals have reduced NADPH oxidase activity (by >40%) and ROS levels (by >30%) compared to WT MHEC. Surprisingly, reduction in ROS did not improve coronary vasomotion, rather endothelium-dependent VEGF-mediated coronary vasodilatation was reduced by >50% in p47phox−/− animals. Western blots and L- citrulline assays showed significant reduction in Akt and eNOS phosphorylation, and NO synthesis, respectively, in p47phox−/− coronary vessels and MHEC. Adenoviral expression of constitutively active eNOS restored VEGF-mediated coronary vasodilatation in p47phox−/−. These data suggest that endothelium-dependent VEGF regulation of coronary vascular tone requires NADPH oxidase-derived ROS to activate PI3K-Akt-eNOS axis.