高尿酸通过miR-155下调eNOS表达而导致内皮细胞功能障碍

High concentration uric acid regulates endothelial function via miR-155

目的高尿酸血症是心血管和肾脏疾病的独立风险因素,本研究拟从miR-155入手初步探索其在高尿酸导致内皮功能障碍过程的作用机制。方法培养人脐静脉内皮细胞系HUVEC,以600μmol/L的尿酸孵育24、48 h之后收集细胞及细胞上清液,检测eNOS的蛋白表达及上清液的NO含量;预测并利用双荧光素酶系统验证miR-155的靶基因,随后利用荧光定量PCR检测高尿酸环境中内皮细胞miR-155的表达情况,通过miR-155 inhibitor的转染检测它对内皮功能障碍的影响。结果 600μmol/L的尿酸能诱导内皮细胞eNOS表达下降,NO分泌减少;microRNA在线分析软件及双荧光素酶报告实验提示eNOS的翻译水平受miR-155直接调控;同时发现高尿酸刺激内皮细胞后miR-155的表达上调,而miR-155 inhibitor能抑制它的表达;内皮细胞转染miR-155 inhibitor之后再进行高尿酸的孵育,eNOS的表达及NO的分泌水平与单独高尿酸孵育组相比均显著升高。结论高尿酸可通过miR-155下调eNOS表达而导致内皮细胞功能障碍。

Objective To investigate high-concentration uric acid-induced endothelial dysfunction mediated by miR-155.Methods Human umbilical vein endothelial cells(HUVECs) were incubated with 600 μmol/L uric acid for 24 and 48 h,and eNOS expression and NO content in the cell culture were measured.The target genes of miR-155 were predicted using on-line analysis software and validated by dual-luciferase system.Real-time PCR was used to detect the expression of miR-155 in endothelial cells incubated with high-concentration uric acid.The effect of miR-155 on endothelial dysfunction was assessed by transfection of its inhibitor into HUVECs.Results The expression of eNOS and NO secretion decreased obviously in HUVECs incubated with 600 μmol/L uric acid.MicroRNA on-line analysis software and dual luciferase reporter experiments suggested that the level of eNOS translation was directly regulated by miR-155.The expression of miR-155 in endothelial cells was upregulated after stimulation with high-concentration uric acid,and was inhibited by transfection of miR-155 inhibitor.Expression of eNOS and secretion of NO were elevated in endothelial cells transfected with miR-155 inhibitor after incubation with high-concentration uric acid.Conclusion High-concentration uric acid can down-regulate eNOS expression via miR-155 to induce endothelial dysfunction.