中文摘要：

目的：研究miR-590．5p对氧化低密度脂蛋白（ox-LDL）诱导人脐静脉内皮细胞（HUVECs）凋亡过程中血凝素样氧化低密度脂蛋白受体1（LOX-1）表达的调节作用，观察miR-590．5p对HUVECs凋亡的影响。方法：HUVECs经ox-LDL（50／ag／mL）作用不同时间（0-48h）。AnnexinV-FITC／PI双染流式细胞仪（FCM）检测细胞凋亡率，实时荧光定量PCR（RT-qPCR）检测miR-590-Sp的表达变化。HUVECs转染miR-590-Sp模拟物（miR-590-5pmimics）后ox-LDL继续作用48h-RT-qPCR和Western印迹分别检测LOX．1mRNA和蛋白的表达情况。FCM检测HUVECs凋亡率的变化。结果：随ox-LDL作用时间的延长，HUVECs凋亡率逐渐升高，miR-590-5p表达逐渐下调。miR-590-5p模拟物转染后可以降低LOX．1mRNA和蛋白的表达，并抑制ox-LDL诱导的HUVECs凋亡。结论：miR-590-5p可抑制ox-LDL诱导的HUVECs凋亡，其机制可能与下调LOX-1基因表达有关。

英文摘要：

Objective： To investigate the effect of miR-590-Sp on the expression of lectin-like oxidized low density lipoprotein receptor 1 （LOX-1） in apoptotic human umbilical vein endothelial cells （HUVECs） induced by ox-LDL, and to explore the role ofmiR-590-Sp in modulating HUVECs apoptosis. Methods： HUVECs were exposed to ox-LDL （50 pg/mL） for 0 to 48 h. Apoptosis was detected by Annexin V-FITC stain and was distinguished from necrosis by propidium iodide （PI） staining. The relative expression level of miR-590-Sp in HUVECs was analyzed using real-time quantitative PCR （RT-qPCR）. HUVECs were transfected with miR-590-5p mimics or miRNA mimics control followed by 50 pg/mL ox-LDL stimulation for 48 h. LOX-1 mRNA and protein were measured by RT-qPCR and Western blot, and apoptosis in HUVECs was analyzed by flow ctyometry afterAnnexin V-FITC/PI double stain. Results： Incubation of HUVECs with 50 μg/mL ox-LDL for 0 to 48 h resulted in a time-dependent induction of apoptotic cell death and down-regulation of miR-590-Sp. Transfection of miR-590-Sp mimics suppressed LOX-1 expression at both mRNA and protein levels, leading to a reduction of ox-LDL-induced apoptosis in HUVECs. Conclusion： MiR-590-Sp protects endothelial cells from ox-LDL induced apoptosis by inhibiting the expression ofLOX-1.