The deubiquitinase YOD1 in renal tubular epithelial cells promotes diabetic kidney disease by stabilizing KEAP1.

Renal tubular epithelial cell (RTEC) injury is an early event in diabetic kidney disease (DKD) and is a key driver of its development and progression. Deubiquitinating enzymes (DUBs) play crucial roles in the progression of diseases by regulating the stability of substrate proteins. This study aims to elucidate the regulatory role and underlying mechanisms of the deubiquitinating enzyme ovarian tumor domain-containing 2 (YOD1) in RTEC injury and DKD. Through transcriptomics and single-cell mRNA sequencing, we confirmed that YOD1 expression is upregulated in diabetic kidneys and that YOD1 is predominantly localized in RTECs. RTEC-specific Yod1 knockout alleviates renal injury in diabetic mice. RNA-seq analysis revealed a positive correlation between YOD1 and the oxidative stress signaling pathway. Interactome analysis revealed the oxidative stress regulatory protein Kelch-like ECH-associated protein 1 (KEAP1) as a YOD1 substrate. YOD1 deubiquitinates and stabilizes KEAP1, which suppresses NRF2 nuclear translocation under high glucose and palmitic acid (HG/PA) stimulation, thus increasing oxidative stress. Similarly, the ROS scavenger N-acetylcysteine (NAC) can alleviate oxidative stress injury to some extent by reducing ROS levels in RTECs. Finally, we confirmed that the YOD1 pharmacological inhibitor G5 has therapeutic effects on kidney injury in diabetic mice. Our findings demonstrate that the YOD1-KEAP1 axis mediates oxidative stress injury in RTECs and highlight that targeting YOD1 represents a potential treatment approach for DKD.