Immunohistochemical Study on O-GlcNAcylation in Diabetic Pathologies: Molecular Mechanisms and Implications

O-linked N-acetylglucosamine (O-GlcNAc) modification, known as O-GlcNAcylation, is a dynamic post-translational modification involving the addition of N-acetylglucosamine to serine or threonine residues. It has emerged as a critical regulator in diabetic pathophysiology. This review summarizes current research on the role of O-GlcNAcylation in hyperglycemia-induced cellular dysfunction, and focuses on vascular smooth muscle cells, renal cytoskeletal proteins, and diabetic complications in animal and human models. Studies reveal that hyperglycemia upregulates O-GlcNAc transferase activity, disrupting the interplay between glycosylation and phosphorylation, thereby impairing signaling pathways and exacerbating vascular proliferation and renal cytoskeletal disorganization. Notable findings include the imbalance of β-actin modifications in diabetic nephropathy, correlated with podocyte damage and glomerular abnormalities. By elucidating these mechanistic pathways, this review underscores the potential of O-GlcNAcylation as a biomarker and a therapeutic target. Future research should focus on tissue-specific effects and pharmacological strategies that mitigate diabetes-induced complications while preserving normal cellular functions.