Identification of proteins related to SIS3 by iTRAQ and PRM-based comparative proteomic analysis in cisplatin-induced acute kidney injury

Abstract

Cisplatin is a commonly nephrotoxic drugs, causing acute kidney injury (AKI). In this study, we aimed to explore the potential regulatory role of the Smad3 phosphorylation inhibitor SIS3 in cisplatin-induced AKI. The cisplatin-induced AKI mouse model was established and treated with SIS3.Using isobaric tags for relative and absolute quantification(iTRAQ) to search for differentially expressed proteins (DEPs) and parallel reaction monitoring (PRM) to verify key DEPs. Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) and Protein-Protein Interaction Networks (PPI) analysis were performed for DEPs. Lipid droplets in cells were observed by oil red O staining and bodipy493/503 staining. Malondialdehyde (MDA) and reactive oxygen species (ROS) levels in cells were detected by commercial kits. The protein expression levels were detected by western blot or immunohistochemistry. Proteomic analysis showed that the identified DEPs were mainly enriched in energy metabolism pathways, especially in lipid metabolism. After applying SIS3 to inhibit the phosphorylation of Smad3, the expression of NDRG1 and fatty acid oxidation key proteins CPT1A and PPARα increased, the expression of lipid synthesis related proteins SREBF1 and SCD1 decreased and the production of lipid droplets, MDA and ROS decreased. In conclusion, SIS3 may alleviate oxidative stress, reduced lipid accumulation and promoted fatty acid oxidation through NDRG1 in cisplatin-induced AKI.