Pi Xinchun, Xie Liang, Portbury Andrea L, Kumar Sarayu, Lockyer Pamela, Li Xi, Patterson Cam
From the UNC McAllister Heart Institute (X.P., L.X., A.L.P., P.L., X.L., C.P.), Department of Medicine (X.P., L.X., A.L.P., P.L., X.L., C.P.), and Department of Chemistry (S.K.), University of North Carolina, Chapel Hill.
Arterioscler Thromb Vasc Biol. 2014 Sep;34(9):2023-32. doi: 10.1161/ATVBAHA.114.303733. Epub 2014 Jul 2.
Reactive oxygen species (ROS) act as signaling molecules during angiogenesis; however, the mechanisms used for such signaling events remain unclear. Stromal cell-derived factor-1α (SDF-1α) is one of the most potent angiogenic chemokines. Here, we examined the role of ROS in the regulation of SDF-1α-dependent angiogenesis.
Bovine aortic endothelial cells were treated with SDF-1α, and intracellular ROS generation was monitored. SDF-1α treatment induced bovine aortic endothelial cell migration and ROS generation, with the majority of ROS generated by bovine aortic endothelial cells at the leading edge of the migratory cells. Antioxidants and nicotinamide adenine dinucleotide phosphate oxidase (NOX) inhibitors blocked SDF-1α-induced endothelial migration. Furthermore, knockdown of either NOX5 or p22phox (a requisite subunit for NOX1/2/4 activation) significantly impaired endothelial motility and tube formation, suggesting that multiple NOXs regulate SDF-1α-dependent angiogenesis. Our previous study demonstrated that c-Jun N-terminal kinase 3 activity is essential for SDF-1α-dependent angiogenesis. Here, we identified that NOX5 is the dominant NOX required for SDF-1α-induced c-Jun N-terminal kinase 3 activation and that NOX5 and MAP kinase phosphatase 7 (MKP7; the c-Jun N-terminal kinase 3 phosphatase) associate with one another but decrease this interaction on SDF-1α treatment. Furthermore, MKP7 activity was inhibited by SDF-1α, and this inhibition was relieved by NOX5 knockdown, indicating that NOX5 promotes c-Jun N-terminal kinase 3 activation by blocking MKP7 activity.
We conclude that NOX is required for SDF-1α signaling and that intracellular redox balance is critical for SDF-1α-induced endothelial migration and angiogenesis.
活性氧（ROS）在血管生成过程中作为信号分子发挥作用；然而，此类信号事件所涉及的机制仍不清楚。基质细胞衍生因子-1α（SDF-1α）是最有效的促血管生成趋化因子之一。在此，我们研究了ROS在SDF-1α依赖性血管生成调节中的作用。
用SDF-1α处理牛主动脉内皮细胞，并监测细胞内ROS的产生。SDF-1α处理诱导牛主动脉内皮细胞迁移和ROS产生，迁移细胞前沿的牛主动脉内皮细胞产生了大部分ROS。抗氧化剂和烟酰胺腺嘌呤二核苷酸磷酸氧化酶（NOX）抑制剂可阻断SDF-1α诱导的内皮细胞迁移。此外，敲低NOX5或p22phox（NOX1/2/4激活所需的亚基）会显著损害内皮细胞的运动能力和管腔形成，表明多种NOX调节SDF-1α依赖性血管生成。我们之前的研究表明，c-Jun氨基末端激酶3活性对于SDF-1α依赖性血管生成至关重要。在此，我们发现NOX5是SDF-1α诱导c-Jun氨基末端激酶3激活所需的主要NOX，并且NOX5和丝裂原活化蛋白激酶磷酸酶7（MKP7；c-Jun氨基末端激酶3磷酸酶）相互关联，但在SDF-1α处理时这种相互作用会减弱。此外，SDF-1α抑制MKP7活性，而敲低NOX5可缓解这种抑制，表明NOX5通过阻断MKP7活性促进c-Jun氨基末端激酶3激活。
我们得出结论，NOX是SDF-1α信号传导所必需的，并且细胞内氧化还原平衡对于SDF-1α诱导的内皮细胞迁移和血管生成至关重要。
