4D label-free quantitative proteomic and phosphoproteomic profiling of the kidney in rat models of antimyeloperoxidase-associated vasculitis.

Abstract

Objectives: The early diagnosis of antimyeloperoxidase (anti-MPO) -associated vasculitis is still a challenge in clinical practice. This study aimed to facilitate the early diagnosis of anti-MPO-associated vasculitis and investigate its pathogenesis.

Methods: We established an animal model of experimental autoimmune vasculitis (EAV), and applied 4D label-free technology to identify proteins and phosphorylated proteins in the kidneys of the EAV group and control group.

Results: A total of 674 differentially expressed proteins (DEPs) were identified by proteomics, including 347 up-regulated and 327 down-regulated proteins. The results of the GO and KEGG enrichment analysis showed that DEPs were mainly involved in complement and coagulation cascade reactions, as well as the formation of neutrophil extracellular traps. According to the analysis of MCODE and hub proteins, FGG, HRG, C3, SERPIND1, ITIH2, A2M were selected as target proteins, and parallel reaction monitoring (PRM) was used to validate the above proteins. The validation results were consistent with the proteomic detection results. Through de-background analysis of differentially expressed phosphorylated proteins, a total of 497 differentially expressed phosphorylated attributed proteins were identified, 256 of which were down-regulated and 241 were up-regulated. These proteins mainly participated in energy metabolism-related pathways. The prediction analysis of upstream phosphorylated kinases suggested that kinases with significantly up-regulated activity included CAMK2D, PAK2, CAMK2B, and PRKAA2, while kinases with down-regulated activity included ADRBK1 and PLK1.

Conclusions: The results of this study could provide some auxiliary indicators for the early diagnosis of anti-MPO-associated vasculitis, and provide a basis for further understanding of its pathogenesis.