Wang Yan, Ji Liang, Jiang Rengui, Zheng Lemin, Liu Donghui
Division of Cardiology, the Affiliated Zhongshan Hospital of Xiamen University, Xiamen Heart Center.
J Atheroscler Thromb. 2014;21(3):204-16. doi: 10.5551/jat.19448. Epub 2013 Nov 13.
As the major atheroprotective particle in plasma, high-density lipoprotein(HDL) is oxidized during atherosclerotic processes. Oxidized HDL(ox-HDL) may lose its cardioprotective properties and develop a proinflammatory and proatherogenic phenotype. The proliferation and migration of vascular smooth muscle cells(VSMCs) play a crucial role in atherogenesis. However, the influence of ox-HDL on VSMC proliferation and migration remains poorly understood.
VSMCs were treated with native HDL(N-HDL) or ox-HDL at varying concentrations for different time intervals and used in several analyses. The degree of cell proliferation was assayed using CCK-8 kits. The level of cell migration was determined using a Transwell chamber and scratch-wound assay. The presence of intracellular reactive oxygen species(ROS) was detected based on ROS-mediated 2',7'-dichlorofluorescein fluorescence. The activation of NADPH oxidase was measured in terms of the Rac1 activity and NADP(＋)/NADPH ratio.
Compared to N-HDL, ox-HDL significantly promoted VSMC proliferation and migration in a dose-dependent manner. In addition, ox-HDL remarkably activated NADPH oxidase and enhanced ROS generation in the VSMCs. Diphenyleneiodonium chloride, an inhibitor of NADPH oxidase, and N-acetylcysteine, a ROS scavenger, efficiently inhibited the ROS production triggered by ox-HDL and subsequently blocked the proliferating and migrating effects of ox-HDL in the VSMCs.
Ox-HDL significantly induces VSMC proliferation and migration by promoting NADPH oxidase activation and ROS production. Furthermore, the inhibition of NADPH oxidase and ROS generation blocks the proliferation and migration of VSMCs induced by ox-HDL. These proliferating and migrating effects of ox-HDL are closely related to its proinflammatory and proatherogenic roles.
作为血浆中主要的抗动脉粥样硬化颗粒，高密度脂蛋白（HDL）在动脉粥样硬化过程中会被氧化。氧化型高密度脂蛋白（ox-HDL）可能会丧失其心脏保护特性，并呈现促炎和促动脉粥样硬化的表型。血管平滑肌细胞（VSMC）的增殖和迁移在动脉粥样硬化形成过程中起着关键作用。然而，ox-HDL对VSMC增殖和迁移的影响仍知之甚少。
用不同浓度的天然HDL（N-HDL）或ox-HDL处理VSMC不同时间间隔，并用于多项分析。使用CCK-8试剂盒检测细胞增殖程度。使用Transwell小室和划痕试验测定细胞迁移水平。基于活性氧（ROS）介导的2'，7'-二氯荧光素荧光检测细胞内ROS的存在。根据Rac1活性和NADP（＋）/NADPH比值测定NADPH氧化酶的活性。
与N-HDL相比，ox-HDL以剂量依赖的方式显著促进VSMC增殖和迁移。此外，ox-HDL显著激活NADPH氧化酶并增强VSMC中的ROS生成。NADPH氧化酶抑制剂二苯基碘鎓氯化物和ROS清除剂N-乙酰半胱氨酸有效抑制ox-HDL触发的ROS产生，并随后阻断ox-HDL对VSMC的增殖和迁移作用。
ox-HDL通过促进NADPH氧化酶激活和ROS产生显著诱导VSMC增殖和迁移。此外，抑制NADPH氧化酶和ROS生成可阻断ox-HDL诱导的VSMC增殖和迁移。ox-HDL的这些增殖和迁移作用与其促炎和促动脉粥样硬化作用密切相关。
