Urinary Proteome Changes in Global Cerebral Ischemia-Reperfusion Injury Rat Model Using Proteomics

Background Cerebral ischemia-reperfusion (I/R) injury is the leading cause of death in severe hypotension caused by cardiac arrest, drowning, and excessive blood loss. Urine can sensitively reflect pathophysiological changes in the brain even at an early stage. Methods In this study, a rat model of global cerebral I/R injury was established via Pulsinelli’s four-vessel occlusion (4-VO) method. The proteomics techniques of data-independent acquisition (DIA) and parallel reaction monitoring (PRM) were applied to profile the urinary proteome. The differentially expressed proteins were subjected to Gene Ontology (GO) and protein-protein interaction (PPI) analysis. Results One hundred and sixty-four proteins significantly differed in the 4-VO rat urine samples compared to the control samples (1.5-fold change, p<0.05). GO analysis showed that the acute-phase response, the ERK1 and ERK2 cascade, endopeptidase activity, blood coagulation, and angiogenesis were overrepresented. After PRM validation, fifteen differentially expressed proteins were identified, and their expression was consistent with the DIA quantification. The abundance of FGG, COMP, TFF2, and HG2A was significantly changed only at 12 h after I/R injury. APOE, FAIM3, FZD1, IL1R2, UROK and CD48 were upregulated only at 48 h after I/R injury. KNG1, CATZ, PTGDS, PRVA and HEPC showed an overall trend of upregulation or downregulation at 12 and 48 h after I/R injury, reflecting the progression of cerebral I/R injury. Conclusion In this study, fifteen differentially expressed urinary proteins were identified and validated in a 4-VO rat model. Eight of these proteins were reported to be associated with cerebral I/R injury. These findings provide important clues to inform the monitoring of cerebral I/R injury and further the current understanding of its molecular biological mechanisms.