OGT accelerates diabetic retinopathy via O-GlcNAcylation of BAP1

Diabetic retinopathy (DR), a prevalent neurovascular complication of diabetes, is a leading cause of blindness in affected individuals. O-linked β-D-N-acetylglucosamine modification (O-GlcNAcylation), a unique form of post-translational modification regulated by O-GlcNAc transferase (OGT) and O-GlcNAcase, plays a critical role in cellular processes. This study aimed to investigate the role of OGT-mediated O-GlcNAcylation and its potential regulatory mechanisms in DR. Using a DR mouse model, we evaluated the effect of OGT on retinal tissue damage. An in vitro model was established by treating human retinal endothelial cells (HRECs) with high glucose (HG). The biological behaviors of HRECs were assessed using Cell Counting Kit-8, EdU incorporation, transwell, and tube formation assays. Underlying mechanisms were explored through quantitative real-time PCR, western blot, and co-immunoprecipitation. Our findings revealed that O-GlcNAcylation levels were significantly elevated both in vitro and in vivo. Knockdown of OGT suppressed the proliferation, migration, and angiogenesis of HG-stimulated HRECs, an effect mediated through the upregulation of BAP1. Mechanistically, OGT was found to interact with BAP1 and promote its O-GlcNAcylation, thereby negatively regulating BAP1 expression. Furthermore, OGT knockdown attenuated retinal tissue damage in diabetic mice, an effect dependent on BAP1. In summary, this study reveals a novel role for OGT-mediated O-GlcNAcylation in DR progression, suggesting its potential as a therapeutic target for DR.