【摘要】 目的研究miR-181a在过氧化氢（H₂O₂）损伤的人脐静脉内皮细胞（HUVECs）中的表达,并探讨miR-181a对H₂O₂诱导的HUVECs活性和凋亡的影响及其机制。方法 MTT法和流式细胞计量术测定HUVECs活性和凋亡;RT-qCR和Western blot测定miR-181a和X连锁凋亡抑制蛋白（XIAP）mRNA及蛋白的表达;Targetscan软件预测miR-181a和XIAP的靶向关系,利用双荧光素酶报告分析和Western blot加以验证。结果 1)H₂O₂呈剂量依赖性抑制HUVECs活性并促进凋亡（P<0.05）;2)miR-181a在H₂O₂处理的HUVECs中显著升高（P<0.05）;3)敲低miR-181a可明显促进H₂O₂诱导的HUVECs活性并抑制细胞凋亡（P<0.05）;4)miR-181a能够与XIAP靶向结合;5)miR-181a过表达可抑制H₂O₂诱导的HUVECs活性并促进细胞凋亡,外源过表达XIAP可减轻miR-181a调控的HUVECs活性和凋亡。结论 miR-181a通过靶向XIAP抑制H₂O₂诱导的HUVECs活性,并促进细胞凋亡,加重HUVECs损伤。更多还原

【Abstract】 Objective To investigate the expression of miR-181 a in hydrogen peroxide（H₂O₂）-injured human umbilical vein endothelial cells（HUVECs） by H₂O₂, and the effect and mechanism of miR-181 a on cell viability and apoptosis. Methods The viability and apoptosis of HUVECs were measured by MTT and flow cytometry assays. miR-181 a and X-linked inhibitor of apoptosis（XIAP） expressions were determined by RT-qCR and Western blot analyses. The binding sites of miR-181 a in XIAP 3′UTR were predicted using Targetscan software and verified by Dual-Luciferase Reporter and Western blot assays. Results 1)H₂O₂ inhibited cell activity while promoted apoptosis of HUVECs in a dose-dependent manner（P<0.05）. 2)miR-181 a was significantly elevated in H₂O₂-treated HUVECs（P<0.05）. 3)Knockdown of miR-181 a promoted H₂O₂-induced cell activity and inhibited apoptosis（P<0.05）. 4)XIAP was identified to be a target for miR-181 a. 5)Overexpression of miR-181 a inhibited H₂O₂-induced cell activity and promoted apoptosis, which was reversed by XIAP restoration. Conclusions miR-181 a stimulates H₂O₂-induced cell activity while inhibites cell apoptosis by targeting at XIAP and then leading to the aggravation of HUVECs injury.更多还原