Abstract: Objective To study the role and mechanism of mir-199-3p in the pathogenesis of diabetic retinopathy (DR). Methods The diabetic model of rats was established by injection of streptozotocin. The expression of miR-199-3p and vascular endothelial growth factor A (VEGFA) in the retina of rats was detected by RT-qPCR. The targeting relationship between miR-199-3p and VegfA in retinal cells was studied by dual luciferase assays. Apoptosis of retinal cells was evaluated by TUNEL staining. Protein of VEGFA and transforming growth factor-β(TGF-β), Hepatocyte growth factor (HGF), pigment epithelium derived factor (PEDF) were detected by Western blot. Results The retinal staining showed that the pathological changes such as retinal capillary dilation and vascular curvature in diabetic rats. The results of reverse transcription showed that the expression of miR-199-3p decreased and VEGFA increased in the retina of diabetic rats significantly. The targeting relationship between miR-199-3p and VegfA was confirmed by dual luciferase assays. The low-expression of miR-199-3p significantly reduced the number of retinal ganglion cells and enhance the apoptosis of retinal cells, while the low expression-miR-199-3p and VEGFA significantly reversed the effects of miR-199-3p on retinal cells(P<0.01). Western blot results showed that the expression of TGF-β and HGF decreased significantly after over-expression of miR-199-3p with the increased expression of PEDF(P<0.001). However, over-expression of miR-199-3p combined with VEGFA expression significantly reversed the expression of these proteins. Conclusions miR-199-3p inhibits diabetic retinopathy by targeting at VegfA.

Key words: miR-199-3p, VEGFA, diabetic retinopathy, retinal ganglion, retinal cells