Abstract：【Objective】To investigate effects of miR-146a on human diabetic retinal pigment epithelial cell injury and novel mechanism. 【Methods】Diabetic retinal pigment epithelial cell injury model was established by culturing human retinal pigment epithelial cells (hRPE) in high glucose medium. When hRPE cells was transfected with miR-146a mimics and cultured with high glucose medium, the expression of miR-146a was detected by real-time PCR. The activity of SOD was measured by xanthine oxidation. The content of MDA was detected by thiobarbituric acid. Apoptosis was detected by flow cytometry. Gene prediction showed that interleukin-1 receptor related kinase-1 (IRAK1) was the possible target gene of miR-146a. So the luciferase reporter system was constructed to identify the targeting relationship. Western blot was further used to detect the effect of up-regulated miR-146a on IRAK1 expression. Finally, when both pcDNA3.1-IRAK1 and miR-146a mimics were co-transfected into hRPE cells, the effects of IRAK1 on MDA, SOD and cell apoptosis in hRPE cells regulated by microRNA-146 under high glucose condition were detected by the above methods. 【Results】The expression of miR-146a was downregulated in hRPE cells after high glucose treatment. In the same condition, the content of MDA increased, SOD activity decreased and cell apoptosis rate increased in hRPE cells. Transfection of miR-146a mimics increased the expression level of miR-146a in hRPE cells under high glucose condition, therefore reduced cellular content of MDA, increased SOD activity and reversed cell apoptosis. The luciferase reporter system showed that miR-146a targeted IRAK1 gene, where the inhibitory IRAK1 protein expression was caused by miR-146a up-regulation. Co-transfection of pcDNA3.1-IRAK 1 and miR-146a mimics reversed the effects of miR-146a on MDA, SOD and cell apoptosis in retinal pigment epithelial cells under high glucose condition. 【Conclusion】miR-146a down-regulation of IRAK1 expression attenuates the damage of diabetic retinal pigment epithelial cells.
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2019, Vol. 36 
