Proteomics analysis in the kidney of mice following oral feeding Realgar

Ethnopharmacological relevance: Realgar, a famous traditional Chinese mineral medicine, has been toxic to the renal system. However, the underlying mechanism of Realgar nephrotoxicity is still unclear. Aim of the study: This study aimed to investigate the potential mechanism of Realgar-induced nephrotoxicity by using a label-free quantitative proteomic method. Materials and methods: 36 mice were randomly divided into four groups: Control group, 0.5-, 1.0, and 2.0 g/kg Realgar group. After one week, serum biochemical parameters and renal histopathological examination were performed. Label-free quantitative proteomics was used to identify differentially expressed proteins which were subsequently analyzed with bioinformatics methods. Western blot was utilized to verify the six representative protein expressions. Results: The results showed that 2.0 g/kg Realgar significantly increased blood urea nitrogen and induced the formation of tube cast of renal tubules, while the lower-dose of 0.5 g/kg and 1.0 g/kg Realgar showed no changes. Label-free proteomic analysis identified 3138 proteins, and 272 of those proteins were screened for significant changes in a dose-dependent manner. Functional enrichment analysis suggested that these proteins could affect the apoptotic process and oxidative stress. Representative proteins in the 2.0 g/kg Realgar group, including Cat, Bad, Cycs, Nqo1, Podxl, and Hmox1, were verified by western blot. Conclusions: The results in this study suggest that apoptosis and oxidative stress might be related to the Realgarinduced nephrotoxicity in mice. Moreover, the strategy of proteomics could contribute to the understanding of the mechanisms of nephrotoxicity in mice exposed to Realgar.

Automated summary

The study found that high-dose Realgar increased blood urea nitrogen and induced the formation of tube cast in renal tubules, while low-dose Realgar had no effect. Proteomic analysis indicated that Realgar affected apoptosis and oxidative stress. Verification of protein expressions suggested that Realgar-induced nephrotoxicity might be related to apoptosis and oxidative stress.