MicroRNA-132通过诱导线粒体氧化应激障碍-铁死亡进程促进动脉粥样硬化

MicroRNA-132 promotes atherosclerosis by inducing mitochondrial oxidative stress mediated ferroptosis

目的探讨MicroRNA-132(miR-132)在动脉粥样硬化斑块中的表达及生物学意义。方法收集在本医院行外周血管造瘘手术的动脉粥样硬化患者的斑块样本及周围正常血管样本各30例,分为实验组(n=30)与对照组(n=30);利用RT-qPCR验证miR-132在30例组织标本中的表达水平;采用脂质体转染技术上调人脐静脉内皮细胞(HUVEC)中miR-132的表达,继而通过流式细胞及激光共聚焦技术分析过表达miR-132的HUVEC内活性氧(ROS)、ROS与线粒体的定位关系、线粒体活性氧超氧化物(mtROS)、线粒体膜电位状态(MMP)以及线粒体膜转换孔通透性(mPTP)的功能变化;通过ELISA检测HUVEC内线粒体氧化还原呼吸链复合体(Ⅰ、Ⅱ、Ⅲ、Ⅳ、Ⅴ型)活性的状态;通过Westernblot检测铁死亡关键蛋白的表达水平。结果与正常血管样本(对照组)相比,miR-132在动脉粥样硬化斑块的表达水平显著上调(P<0.001);相比于正常HUVEC,脂质体转染的HUVEC内miR-132表达量显著上升(P<0.001),细胞内ROS明显增加(P<0.001),且大部分ROS与线粒体存在共定位关系;同时于正常HUVEC,miR-132过表达的HUVEC细胞内MMP下降(P<0.001)、mtROS升高(P<0.001)、线粒体活性氧mPTP更多开放(P<0.001),继而引起线粒体氧化还原呼吸链应激障碍,铁死亡关键蛋白GPX4显著下调(P<0.001)、氧化蛋白NOX4显著增多(P<0.001)。结论MiR-132可通过诱导线粒体氧化应激障碍-铁死亡进程促进动脉粥样硬化,有望成为动脉粥样硬化的治疗靶点。

Objective To explore the expression of microRNA-132(miR-132)and its potential role in the development of atherosclerosis(AS).Methods Thirty AS samples and 30 samples of normal peripheral vessels were collected from atherosclerotic patients undergoing peripheral angiostomy in our hospital for detecting the expression level of miR-132 using RT-qPCR.The expression of miR-132 in human umbilical vein endothelial cells(HUVEC)was up-regulated by liposome transfection,and intracellular reactive oxygen species(ROS),localization relationship between ROS and mitochondria,functional changes of mitochondrial reactive oxygen superoxide species(mtROS),mitochondrial membrane potential(MMP)and opening of mitochondrial permeability transition pore(mPTP)were analyzed by flow cytometry and laser confocal microscopy.The activity of mitochondrial redox respiratory chain complex(type I,II,III,IV and V)in HUVECs was detected using ELISA,and the expression levels of key iron death proteins were detected with Western blotting.Results RT-qPCR results showed that miR-132 was significantly up-regulated in atherosclerotic plaques compared with normal vascular samples(P<0.001).Compared with control HUVECs,HUVECs overexpressing miR-132 showed a significantly increased level of intracellular ROS(P<0.001),and most of ROS was colocalized with mitochondria.HUVECs overexpressing miR-132 also showed significantly decreased MMP(P<0.001)and obviously increased mtROS(P<0.001)and opening of mPTP(P<0.001),which led to mitochondrial REDOX respiratory chain stress disorder.The key iron death protein GPX4 was significantly down regulated and the oxidized protein NOX4 was significantly increased in miR-132-overexpressing HUVECs(P<0.001).Conclusion MiR-132 promotes atherosclerosis by inducing mitochondrial oxidative stress-mediated ferroptosis,which may serve as a promising therapeutic target for AS.