Quantitative Proteomics Reveals Significant Downregulation of Glutathione Metabolism in Sepsis-Induced Liver Injury

Sepsis-induced liver injury (SILI) is a severe complication of sepsis and is strongly associated with adverse clinical outcomes. However, the molecular mechanisms driving SILI pathogenesis remain poorly understood. In this study, we applied data-independent acquisition (DIA)-based quantitative proteomics to characterize protein expression profiles in liver tissues from 7 patients with SILI and 14 control patients. A total of 335 proteins were significantly dysregulated in SILI liver tissues, including 126 upregulated and 209 downregulated proteins. GO and KEGG pathway analyses revealed that the upregulated proteins were predominantly enriched in the cellular response to hypoxia and lysosome pathways, whereas the downregulated proteins were mainly associated with metabolic processes, particularly glutathione metabolism. Six key glutathione metabolism-related enzymes (GCLC, GSTO1, SOD1, GPX4, PRDX6, and IDH1) were selected for validation and were confirmed to be markedly reduced in SILI liver tissues by immunoblotting and qPCR. Correlation analyses further demonstrated that decreased expression of these enzymes was strongly associated with elevated markers of inflammation, coagulation disorders, and hepatic dysfunction, linking impaired antioxidant capacity to disease severity. Collectively, our findings reveal a distinct proteomic signature in SILI, characterized by profound suppression of glutathione metabolism, offering mechanistic insight into redox imbalance during SILI. These results highlight glutathione metabolic pathways as promising therapeutic targets for mitigating hepatocellular dysfunction in sepsis.