O-GlcNAcylation Stabilizes NEK7 to Drive Podocyte Pyroptosis in Diabetic Kidney Disease

作者：Wen Chen, Jiarong Liu, Yun Zou, Fang Lü, Junping Zhang, Ying Hu, Jin-jun Xu, Jiao Wang · 发表于：Diabetes · 年份：2025 · DOI：10.2337/db25-0484 · 被引用次数：4 · 研究领域：Inflammasome and immune disorders、Renal Diseases and Glomerulopathies、Polysaccharides and Plant Cell Walls

Diabetic kidney disease (DKD) progression involves NIMA-related kinase 7 (NEK7)-driven podocyte pyroptosis, with hyperglycemia-induced O-GlcNAcylation as a key posttranslational regulator. This study elucidates how O-GlcNAc modification governs NEK7 stability and its pathological role. We used clinical DKD specimens, high-glucose-stimulated podocytes, and streptozotocin-induced diabetic mice to first examine NEK7, O-GlcNAc, O-GlcNAc transferase (OGT), and glutamine fructose-6-phosphate amidotransferase 1 (GFPT1) expression, confirming the pyroptosis role of NEK7 via siRNA knockdown. Bioinformatic analysis predicted O-GlcNAcylation motifs, validated by T302A mutagenesis and coimmunoprecipitation. Protein stability was assessed using cycloheximide chase and ubiquitination assays. Therapeutic efficacy of the GFPT1 inhibitor (6-diazo-5-oxo-l-norleucine) DON was evaluated in vitro and in vivo through biochemical parameters, histopathology, and pyroptosis markers. Chronic hyperglycemia activated the hexosamine biosynthetic pathway (HBP), elevating pathology-associated O-GlcNAc modifications that promoted NEK7 accumulation via posttranslational stabilization. This was accompanied by upregulated O-GlcNAc, OGT, and GFPT1 in DKD glomeruli and high-glucose podocytes. Crucially, threonine 302 was identified as the primary O-GlcNAcylation site of NEK7. This modification reduced proteasomal degradation, extended NEK7 half-life, and enhanced NLRP3 inflammasome activation and interleukin rel...