Cholesterol sulfate as a novel theranostic target for sepsis-induced liver injury through Beclin1-mediated autophagy enhancement and pyroptosis suppression

Abstract

Sepsis remains a life-threatening syndrome, and septic liver injury is a frequent and critical complication for which no specific pharmacological therapy exists. Current biomarkers lack sufficient specificity for early diagnosis and severity assessment, highlighting an urgent need for novel diagnostic and therapeutic strategies. To identify key metabolites involved in sepsis pathogenesis and to evaluate the diagnostic and therapeutic potential of cholesterol sulfate (CS) in sepsis-induced liver injury, as well as to elucidate the underlying molecular mechanisms. We performed transcriptomic (GSE65682) and metabolomic (SepsisLiMetDB) screens sequentially and independently to identify sepsis-associated metabolites. The functional role of CS was evaluated in cecal ligation and puncture (CLP) mouse model using both exogenous CS supplementation and Sult2b1 genetic knockout approaches, as well as in vitro using primary hepatocytes and AML12 cells. The underlying molecular mechanisms were explored via molecular docking, molecular dynamics simulation, cellular thermal shift assay, co-immunoprecipitation, MDC staining, GFP-LC3/LysoTracker Red co-localization, ROS detection, and pyroptosis marker analysis in AML12 cells with or without Beclin1 knockdown. Therapeutic efficacy was compared with clinically used agents (reduning and ulinastatin) in a mouse endotoxemia model. Diagnostic potential was assessed in independent bacterial sepsis ( n = 114) and COVID-19 ( n = 43) cohorts. Through unbiased multi-omics screening, we identified CS as one of the most markedly depleted metabolites in sepsis. Sult2b1 -deficient mice lacking endogenous CS showed exacerbated systemic inflammation, aggravated liver injury, and mortality—all of which were significantly reversed by exogenous CS supplementation. Mechanistically, CS directly bound Beclin1, suppressed its ubiquitin-proteasome degradation, enhanced autophagic flux, and attenuated oxidative stress and GSDMD-mediated pyroptosis. Notably, CS exhibited superior efficacy to Reduning and comparable therapeutic effects to Ulinastatin. Clinically, reduced circulating CS levels correlated with both bacterial and viral sepsis and with disease severity, supporting its potential diagnostic value. Our study establishes, for the first time, CS as a functionally protective metabolite in sepsis, with therapeutic efficacy superior to existing clinical agents, and identify circulating CS as a potential diagnostic biomarker for sepsis and disease severity.