The protective effect of miR⁃92a inhibitor on glucose⁃induced human umbilical vein endothelial cells dysfunction

Objective To investigate the effect and mechanism of miR-92a in glucose-induced endothelial cells dysfunction. Method Primary human umbilical vein endothelial cells were stimulated by different concentration (5 mmol/L and 30 mmol/L)of glucose. The effect of the miR-92a inhibitor was observed by using lipofection transfection. The cells were divided into 4 groups: blank control group (Con), high glucose group (HG), transfecting negative control group (NC) and transfecting miR-92a inhibitor group(IN). The level of miR-92a was detected by qRT-PCR and florescence observation. Hoechst staining was used to investigate the change of nucleus. MTS was applied to observe cell activity. The level of caspase-3 and cleaved caspase-3 protein level were analyzed by Western blotting. Results Compared with the Con group, HUVECs treated with high concentration of glucose have induced significant morphologic damage and apoptosis. The miR-92a level of HG group was increased for 31% (1.31±0.37 vs 1, t=1.93, P<0.05) and cell activity was decreased for 19% ((81%±2%) vs 1, t= -29.85 , P<0.01) ,while caspase-3/cleaved caspase-3 protein level was increased for 24% (0.31±0.07 vs 0.25±0.02, t=2.18, P<0.05). In contrast, compared with HG group, there were significant alleviation on morphologic damage and apoptosis in IN group. Cell activity of IN group was increased for 9% than that in HG group ((88%±11%) vs (81%±2%), t=2.18, P<0.05) and cleaved caspase-3/caspase-3 was reduced for 26% (0.23±0.03 vs 0.31±0.07, t= -2.65, P<0.05). Conclusion miR-92a inhibitor may release high-glucose-induced endothelial damage and reduce apoptosis pathway activation. miR-92a maybe the potential treatment target of diabetes vascular complications. Key words: Endothelial cells; microRNAs; High glucose; Cell activity; Caspase-3