Objective To investigate the effect of TLR4 on the ROS and mitochondrial membrane potential of vascular endothelial cells af-ter ox - LDL action. Methods The levels of TLR4 mRNA and protein in vascular endothelial cells after ox - LDL were measured by qRT - PCR and Western blot respectively. Transfection of TLR4 small interference RNA and small interference RNA negative control in vascular endothelial cells was performed,the levels of TLR4 mRNA and protein in vascular endothelial cells were measured by qRT - PCR and Western blot respective-ly. Vascular endothelial cells after transfection with ox - LDL were transfected,cell apoptosis was measured by flow cytometry,the content of ATP was determined by the luciferase gene report system,the content of ROS was determined by DCFH - DA method,the JC - 1 method was used to determine the mitochondrial membrane potential,determination of Cytochrome C protein in cytoplasm and mitochondria by Western blot. Results The levels of TLR4 mRNA and protein in vascular endothelial cells after ox - LDL were significantly higher than those of untreated cells (P 0. 05). The number of apoptotic cells increased after ox - LDL treatment,the cell mitochondrial membrane potential and ATP level were reduced,the level of ROS in the cells was elevated,the decrease of Cytochrome C protein in mitochondria,the in-crease of Cytochrome C protein in the cytoplasm,the difference was statistically significant compared with the untreated cells (P 0.05).ox-LDL处理以后的细胞凋亡增多,细胞线粒体膜电位和ATP水平降低,细胞中ROS水平升高,线粒体中Cytochrome C蛋白减少,胞浆中Cytochrome C蛋白增多,与未经处理的细胞相比差异有统计学意义(P<0.05).下调TLR4后的血管内皮细胞经ox-LDL处理以后,细胞凋亡率降低,线粒体膜电位和ATP水平升高,细胞中ROS水平降低,线粒体中Cytochrome C蛋白增多,胞浆中Cytochrome C蛋白减少,与单纯ox-LDL处理的细胞相比,差异有统计学意义(P<0.05).结论 TLR4表达下调后可以提高ox-LDL处理后血管内皮细胞线粒体膜电位,促进细胞ATP合成,减少细胞中ROS的积累,减少线粒体中Cytochrome C蛋白的释放,减少线粒体损伤,减少细胞凋亡发生.
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