Protein O-GlcNAcylation coupled to Hippo signaling drives vascular dysfunction in diabetic retinopathy [3A]

Metabolic disorder is emerging as a crucial contributor to the pathogenesis of diabetic vascular complications including diabetic retinopathy (DR), the leading cause of blindness in the working-age population. Yet, the underlying molecular mechanisms of how the disturbed metabolic homeostasis contribute to vascular dysfunction in DR remain elusive. O-GlcNAcylation modification act as a nutrient sensor particularly sensitive to ambient glucose. Here, we observed pronounced O-GlcNAc elevation in retina endothelial cells (ECs) of DR patients and mouse models. Endothelial-specific depletion or pharmacological inhibition of O-GlcNAc transferase efficiently mitigated vascular dysfunctions. Mechanistically, we found that YAP/TAZ, key effectors of the Hippo pathway, are O-GlcNAcylated in DR. We identified Thr383 as an O-GlcNAc site on YAP, which inhibits its phosphorylation at Ser397, leading to its stabilization and activation. Consequently, highly activated YAP/TAZ, promotes vascular dysfunction by inducing a pro-angiogenic and glucose metabolic transcriptional program. These findings emphasize the critical role of O-GlcNAc-Hippo axis in DR pathogenesis and suggest its unique potential as a therapeutic target. To determine the mechanism of O-GlcNAcylation in regulating the function of retinal ECs, we profiled transcriptome from PUGNAc or vehicle treated HRCECs. And HRCECs were treated with DMSO or 25 μM PUGNAc for 24 hr, and total RNA was harvested for RNA-seq.