METHODS: The primary HRGEC were mainly studied, light microscopy was used to detect changes in cell morphology. Quantitative Real Time-Polymerase Chain Reaction, Western Blot, immunofluorescence were aimed to observe the mRNA and protein expression levels of target gene ETS-1, downstream factors VCAM-1, MCP-1 and cleaved caspase-3 in each group after high glucose treatment as well as transfection with miR-155 mimics or inhibitor.
RESULTS: The expression of inflammatory factors and apoptosis of HRGEC cells increased under high glucose treatment. Compared with normal-glucose treatment, the expression of microRNA-155 markedly increased in HRGECs treated with high-glucose, as well as the mRNA and protein levels of ETS-1, VCAM-1, MCP-1 and cleaved caspase-3. Overexpression of microRNA-155 remarkably downregulated mRNA and protein levels of ETS-1, VCAM-1, MCP-1 and cleaved caspase-3, whereas miRNA-155 knockdown upregulated their levels. In addition, HRGEC cells were transfected with miR-155 mimics and ETS-1 siRNA with high glucose stimulation. The expression of ETS-1 was positively correlated with the expression of downstream factors VCAM-1 and MCP-1. These results suggest that ETS-1 can mediate endothelial cell inflammation by regulating VCAM-1 and MCP-1.
CONCLUSIONS: MiR-155 can negatively regulate the expression of target gene ETS-1 and its downstream factors VCAM-1, MCP-1 and cleaved caspase-3, thus mediating the inflammatory response and apoptosis of HRGEC.
方法:主要研究HRGEC,光学显微镜用于检测细胞形态的变化。定量实时聚合酶链反应,西方印迹,免疫荧光法观察高糖处理和miR-155模拟物或抑制剂转染后各组靶基因ETS-1、下游因子VCAM-1、MCP-1和裂解的caspase-3的mRNA和蛋白表达水平。
结果:高糖处理下HRGEC细胞的炎症因子表达和凋亡增加。与正常血糖治疗相比,在高糖处理的HRGECs中microRNA-155的表达明显增加,以及ETS-1,VCAM-1,MCP-1和裂解的caspase-3的mRNA和蛋白质水平。microRNA-155的过表达显着下调ETS-1,VCAM-1,MCP-1和裂解的caspase-3的mRNA和蛋白质水平,而miRNA-155敲低则上调了它们的水平。此外,用miR-155模拟物和具有高葡萄糖刺激的ETS-1siRNA转染HRGEC细胞。ETS-1的表达与下游因子VCAM-1和MCP-1的表达呈正相关。这些结果表明ETS-1可以通过调节VCAM-1和MCP-1介导内皮细胞炎症。
结论:MiR-155可以负调控靶基因ETS-1及其下游因子VCAM-1、MCP-1和cleavedcaspase-3的表达,从而介导HRGEC的炎症反应和凋亡。