LncRNA MEG3 overexpression inhibits the development of diabetic retinopathy by regulating TGF-β1 and VEGF.

In view of the high incidence of diabetic retinopathy and the functionality of long non-coding RNA (lncRNA) maternally expressed gene 3 (MEG3) in different disease models, the present study aimed to investigate the role of MEG3 in diabetic retinopathy. In the study, patients with diabetic retinopathy, diabetic patients without retinopathy as well as healthy people were included. Fasting blood was extracted from each participant. Serum MEG3 levels were detected by everse transcription-quantitative polymerase chain reaction (RT-qPCR) and serum vascular endothelial growth factor (VEGF) and transforming growth factor-β1 (TGF-β1) levels were detected by ELISA. Also, the effects of high glucose treatment on the expression of MEG3 and VEGF and the effects of MEG3 overexpression on expression of VEGF and TGF-β1 in high glucose-treated ARPE-19 cells were detected by RT-qPCR and western blot analysis to determine the mRNA and protein levels, respectively. It was indicated that serum levels of MEG3 were significantly lower, while the serum levels of VEGF and TGF-β1 were significantly higher in patients with diabetic retinopathy and diabetic patients without retinopathy compared with the healthy controls. Furthermore, slight differences were found between patients with diabetic retinopathy and diabetic patients without retinopathy; however, these differences were not significant. The findings indicated that high glucose upregulated the expression of VEGF mRNA and downregulated the expression of MEG3, MEG3 overexpression reduced the increased expression levels of VEGF and TGF-β1 induced by high glucose treatment. Therefore, it was concluded that lncRNA MEG3 overexpression may inhibit the development of diabetic retinopathy by inhibiting TGF-β1 and VEGF expression.