Long noncoding RNA BDNF‐AS inversely regulated BDNF and modulated high‐glucose induced apoptosis in human retinal pigment epithelial cells

In this study, we characterized the functional role of long noncoding RNA (lncRNA), brain derived neurotrophic factor anti‐sense (BDNF‐AS) in regulating D‐glucose‐induced (DGI) apoptosis in human retinal pigment epithelial (RPE) cells. Human RPE cell line, ARPE‐19 cells were cultured in vitro and treated with various concentrations of D‐glucose for 24 h. A TUNEL assay was applied with immunohistochemical and quantitative approaches to assess the apoptotic effect of D‐glucose. Under the condition of 50 mM D‐glucose, qPCR was used to assess gene expression of BDNF and BDNF‐AS in ARPE‐19 cells. Using siRNA transfection, BDNF‐AS was endogenously knocked down in ARPE‐19 cells. The effects of BDNF‐AS downregulation on DGI apoptosis and BDNF expression were assessed by TUNEL assay, qPCR, and Western blot, respectively. Furthermore, in BDNF‐AS‐downregulated ARPE‐19 cells, secondary siRNA transfection was conducted to knock down endogenous BDNF expression. Its effect on BDNF‐AS‐associated apoptotic regulation was further evaluated. High concentrations of D‐glucose induced significant apoptosis in ARPE‐19 cells in vitro. With treatment of 50 mM D‐glucose, BDNF was markedly downregulated whereas BDNF‐AS upregulated in ARPE‐19 cells. SiRNA‐mediated BDNF‐AS downregulation ameliorated DGI apoptosis and upregulated BDNF in ARPE‐19 cells. In addition, inhibiting BDNF reversed the protective effect of BDNF‐AS downregulation on DGI apoptosis. Our results suggest that BDNF‐AS, through inverse regulation of BDNF, might play a critical role in the process of DGI apoptosis in diabetic retinopathy.