Integrated Multi-Omics Analysis and Experimental Validation Identify BCAT1 as a Critical Driver of Hepatocyte Pyroptosis in Acute-On-Chronic Liver Failure.

Acute-on-chronic liver failure (ACLF) is characterized by profound metabolic dysfunction and high mortality. Identifying amino acid metabolism-related biomarkers is crucial for early diagnosis and therapeutic intervention. Amino acid metabolism-related genes (AAMGs) and ACLF transcriptomic data were integrated to identify core genes via weighted gene co-expression network analysis (WGCNA) and differential expression analysis. Three machine learning (ML) algorithms-Random Forest, SVM-RFE, and Boruta-were applied to screen hub genes. Specific cellular profiles and immune landscapes were characterized using single-cell RNA sequencing (scRNA-seq) and ssGSEA. The pathological role of BCAT1 was investigated in APAP-induced ACLF models. A total of 26 genes were identified at the intersection of module genes, DEGs, and AAMGs. ML confirmed a three-gene signature (BCAT1, RPS6, OAT) with high diagnostic accuracy. ScRNA-seq analysis further verified that BCAT1 is predominantly expressed in hepatocytes, indicating its cell-type specific role in liver injury progression. In vitro and in vivo experiments demonstrated that BCAT1 exacerbates hepatocyte injury by activating the GSDMD/Caspase-1-mediated pyroptosis pathway. Our study reveals that BCAT1 is a pivotal driver of hepatocyte pyroptosis in ACLF. Targeting the BCAT1-mediated metabolic-inflammatory axis offers a promising therapeutic strategy for managing ACLF.