S-nitrosylation of peroxiredoxin 2 exacerbates hyperuricemia-induced renal injury through regulation of mitochondrial homeostasis.

Protein S-nitrosylation (SNO), a redox-based posttranslational modification of cysteine thiols, plays a crucial role in various signaling pathways. Peroxiredoxin 2 (PRDX2) is one of the most potent ROS scavenging proteins, providing protection against oxidative stress damage, with its function regulated by SNO. However, the precise role of SNO-PRDX2 in hyperuricemic nephropathy remains poorly understood. In this study, we identified PRDX2 as a highly S-nitrosylated target in hyperuricemic nephropathy using a biotin switch assay. The elevation of SNO-PRDX2 was observed in kidneys of hyperuricemic mice as well as in uric acid (UA)-treated human renal tubular epithelial (HK-2) cells. S-nitrosoglutathione (GSNO), an endogenous nitric oxide carrier, induced SNO modification of PRDX2, promoting mitochondrial dysfunction, oxidative stress, and cell apoptosis in HK-2 cells. Transfection with a plasmid containing a mutated cysteine 172 (Cys172) of PRDX2 yielded a decrease in SNO-PRDX2 levels in both hyperuricemic mice and UA-cultured HK-2 cells. Furthermore, administration of adeno-associated viruses carrying the Cys172-mutated PRDX2 significantly ameliorated renal interstitial fibrosis and reduced mitochondrial dysfunction, oxidative stress, and cell apoptosis in HUA-treated mice. In conclusion, our findings indicate that SNO modification of PRDX2 at Cys172 mediates HUA-induced kidney interstitial fibrosis, suggesting that SNO-PRDX2 may serve as a potential therapeutic target for HUA-induced renal injury.