Abstract
Purpose :
This study aimed to explore the effects of intravitreal injection of microRNA-126 (miR-126) on a rat oxygen-induced retinopathy (OIR) model by VEGF expression.
Methods :
We tested the effect of six microRNAs, miR-15b, -16, -126, -214, -377, and -410 on VEGF expression in human RPE cell line and rat RPE cell line. Then, the rats were randomly divided into a normal control group and OIR group. All the rats in the OIR group were assigned to the following four treatment groups, including the blank group (OIR mice without any treatment), the BSS group (treated with intravitreal injection of BSS), the miR-126 group (treated with intravitreal injection of miR-126), and the miR-126 plasmid group (treated with plasmid pCMV-miR-126/liposome mixture intravitreal injection). The expression levels of VEGF in the intraocular fluid and retina from OIR rats were determined by enzyme-linked immunosorbent assay. Finally, the effects of miR-126 on retinal neovascularization in OIR rat were identified with flat mounted CD31 stained retinal sections.
Results :
In human and rat RPE cell lines, we demonstrated that miR-16, -126, -214, -377, and -410 effectively suppressed VEGF expression (all p<0.05). However, the effect of miR-15 on VEGF suppression was significant in human RPE cell (p<0.05) but not in rat RPE cell lines. We observed the strikingly miR-126 activity in reducing the expression of VEGF in both human and rat RPE cell lines. In the OIR rat model, intravitreal injection of miR-126 caused transfection of retinal cells and significantly reduced the VEGF expression in the retinal tissues compared with the BSS group and blank group (all p<0.05). Furthermore, intravitreal injection of miR-126 plasmid efficiently downregulates VEGF expression in the intraocular fluid compared with the BSS group, retinal tissues compared with the BSS group and blank group, and effectively suppressed retinal neovascularization as compared with the blank group (all p<0.05).
Conclusions :
Our results show that miR-126 could effectively reduce the expression of VEGF in the RPE cells and inhibit neovascularization in the OIR model. Our study provides a novel treatment strategy for retinal neovascularization by using a microRNA approach inhibiting VEGF expression.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.