miR-221对高糖诱导的人视网膜血管内皮细胞凋亡的作用机制

目的：研究miR-221对高糖诱导的人视网膜血管内皮细胞(HRCECs)凋亡的影响，并探讨其作用机制。

方法：用葡萄糖30mmol/L处理HRCECs 48h建立高糖诱导的HRCECs细胞； 将HG+miR-NC组(转染miR-NC)、HG+miR-221组(转染miR-221 mimics)、HG+anti-miR-NC组(转染anti-miR-NC)、HG+anti-miR-221组(转染anti-miR-221)、HG+miR-221+pcDNA 3.1组(共转染miR-221 mimics和pcDNA 3.1)、HG+miR-221+pcDNA 3.1-MDM2组(共转染miR-221 mimics和pcDNA 3.1-MDM2)，用脂质体法转染至HRCECs细胞，再进行高糖处理； qRT-PCR法检测细胞中miR-221、p53、MDM2的表达； Western blot检测细胞中p53、MDM2的蛋白表达； 流式细胞术检测细胞的凋亡。

结果：与NG组相比，高糖诱导的HRCECs细胞中miR-221、p53的表达显著升高，MDM2的表达显著降低，细胞凋亡率显著升高； 过表达miR-221可使高糖诱导的HRCECs细胞的凋亡率升高更明显，抑制miR-221可下调高糖诱导的HRCECs细胞的凋亡并下调p53，上调MDM2； 过表达MDM2则可逆转抑制miR-221对高糖诱导的HRCECs细胞的抗凋亡作用及对p53、MDM2的调控。

结论：miR-221可促进高糖诱导的人视网膜血管内皮细胞凋亡，其机制与p53/MDM2信号通路有关。

Molecular mechanism of miR-221 promoting apoptosis of human retinal vascular endothelial cells induced by high glucose by regulating p53/MDM2 signaling pathway

AIM: To study the effect of miR-221 on apoptosis of high glucose-induced human retinal vascular endothelial cells and to explore its mechanism.

METHODS: High-glucose-induced HRCECs were established by treatment of HRCECs cells with glucose at 30mmol/L for 48h; HG+miR-NC group(transfected miR-NC), HG+miR-221 group(transfected miR-221 mimics), HG+anti-miR-NC group(transfected anti-miR-NC), HG+anti-miR-221 group(transfected anti-miR-221), HG+miR-221+pcDNA 3.1 group(co-transfected miR-221 mimics and pcDNA 3.1), HG+miR-221+pcDNA 3.1-MDM2 group(co-transfected miR-221 mimics and pcDNA 3.1-MDM2), transfected into HRCECs cells by liposome method, and then treated with high glucose; qRT-PCR method for detection the expression of miR-221, p53 and MDM2; the protein expression of p53 and MDM2 were detected by Western blot. The apoptosis of cells was detected by flow cytometry.

RESULTS: Compared with NG group, the expression of miR-221 and p53 was significantly increased, the expression of MDM2 was significantly decreased, and the apoptosis rate was significantly increased in high glucose-induced HRCECs. Overexpression of miR-221 induced apoptosis of high glucose-induced HRCECs cells is more obvious. Inhibition of miR-221 can down-regulate the apoptosis of high glucose-induced HRCECs and down-regulate p53, up-regulate MDM2; overexpression of MDM2 can reverse the inhibition by miR-221 anti-apoptotic effect of cells and regulation of p53 and MDM2 of high-glucose-induced HRCECs.

CONCLUSION: miR-221 can promote the apoptosis of high-glucose-induced human retinal vascular endothelial cells, and its mechanism is related to p53/MDM2 signaling pathway.