MiR-185-5p is Involved in Regulating the Abnormal Proliferation of Retinal Microvascular Endothelial Cells via Targeting CXCR4

This study aimed to explore the expression profile of miR-185-5p in proliferative DR (PDR), and further evaluate its diagnostic value and possible mechanism of miR-185-5p in PDR.
The level of miR-185-5p was detected by qRT-PCR. The ROC curve was established to estimate the diagnostic ability of miR-185-5p. Transwell experiment and cell counting kit-8 (CCK-8) assays were conducted to assess the effect of miR-185-5p on the migration and proliferation of human retinal endothelial cells (HRECs) induced by high glucose. Enzyme linked immunosorbent assay (ELISA) was used to detect the concentrations of inflammatory factors. The luciferase reporter gene experiment was used to prove the interaction between miR-185-5p and CXCR4.
Compared to the control group, the expression of miR-185-5p was significantly up-regulated in both the type 2 diabetes mellitus (T2DM) group and the PDR groups, with higher levels in the PDR group than in the T2DM group. The ROC curve reveals that serum miR-185-5p can distinguish PDR patients from T2DM patients. MiR-185-5p levels in HRECs increased significantly after high glucose induction. High glucose induction also promoted the migration, proliferation and inflammation response of HRECs. However, when the intracellular miR-185-5p level was down-regulated by miR-185-5p inhibitor transfection, these effects were inhibited. The luciferase reporter gene assay showed that miR-185-5p directly targets CXCR4.
The expression of miR-185-5p is out of balance in PDR and it may be involved in regulating the migration and proliferation of HRECs by regulating CXCR4.

本研究旨在探究miR-185-5p在增生性糖尿病视网膜病变（proliferative DR, PDR）中的表达谱，并进一步评估其在PDR中的诊断价值及潜在作用机制。
采用实时荧光定量聚合酶链反应（quantitative real-time polymerase chain reaction, qRT-PCR）检测miR-185-5p的表达水平。绘制受试者工作特征曲线（Receiver Operating Characteristic, ROC）以评估miR-185-5p的诊断效能。通过Transwell实验与细胞计数试剂盒-8（cell counting kit-8, CCK-8）实验，探究miR-185-5p对高糖诱导的人视网膜内皮细胞（human retinal endothelial cells, HRECs）迁移与增殖的影响。采用酶联免疫吸附试验（enzyme linked immunosorbent assay, ELISA）检测炎症因子浓度。通过荧光素酶报告基因实验验证miR-185-5p与CXCR4的靶向相互作用。
与对照组相比，2型糖尿病（type 2 diabetes mellitus, T2DM）组与PDR组的miR-185-5p表达量均显著上调，且PDR组的表达水平高于T2DM组。ROC曲线分析显示，血清miR-185-5p可有效区分PDR患者与T2DM患者。高糖诱导后，HRECs内的miR-185-5p水平显著升高。高糖诱导同时可促进HRECs的迁移、增殖及炎症反应。但通过转染miR-185-5p抑制剂下调细胞内miR-185-5p水平后，上述效应均被抑制。荧光素酶报告基因实验证实，miR-185-5p可直接靶向结合CXCR4。
miR-185-5p在PDR中表达失衡，其可能通过调控CXCR4参与HRECs的迁移与增殖过程。