Downregulation of General Control Nonderepressible 2/Eukaryotic Initiation Factor 2α Attenuates Inflammation, Oxidative Stress and Cell Apoptosis in Retinal Cells Induced by High Glucose

Abstract

Background: Diabetic retinopathy (DR), the frequent complication of diabetes mellitus, has been the main factor of clinical blindness. It is of great clinical significance to seek a novel therapeutic target of DR. The present study aims to investigate the important role of GCN2/eIF2α in DR and the underlying mechanism. Materials and Methods: The expression levels of GCN2 and p-eIF2α were measured by western blot assay and q-PCR. The inflammation levels were assessed by ELISA assay and oxidative stress was measured by colorimetric method. Then, the key proteins related to the function of endothelial cell were measured by western blot assay. Cell apoptotic rate was detected by flow cytometry and proteins related to cell apoptosis were detected by western blot assay. Results: High glucose activated GCN2/eIF2α signaling pathway in HRCECs. Downregulation of GCN2 attenuated HG-induced cell apoptosis, inflammatory and oxidative stress in HRCECs. Meanwhile, downregulation of GCN2 ameliorated HG-induced endothelial cell dysfunction. Inhibition of GCN2 inhibited p-eIF2α, ATF4, CHOP and activated UCP2. Conclusion: The results in this study proved that knockdown of GCN2 could significantly mitigate HG-induced injury, suggesting GCN2/eIF2α as a potential target for DR therapy.