Argatroban mitigates Klebsiella pneumoniae liver injury by attenuating ZBP1-dependent PANoptosis.

BACKGROUND: Klebsiella pneumoniae (K. pneumoniae) liver abscess (KPLA) is frequently accompanied by thrombophlebitis and systemic inflammation. Argatroban, a direct thrombin inhibitor, has anti-inflammatory potential, but its efficacy and mechanism in KPLA remain unclear. METHODS: A murine KPLA model was established using a hypervirulent, patient-derived K. pneumoniae strain, with mice receiving vehicle or argatroban (10 mg kg-1/day, i.p.). Survival, liver pathology, vascular permeability, inflammatory responses, and transcriptomic changes were evaluated. Hepatocyte responses were investigated using KP-LPS-stimulated THLE-2 cells. ZBP1 localization, protein interactions, and functional dependence were assessed by immunofluorescence, co-immunoprecipitation, and ZBP1 silencing. RESULTS: Argatroban significantly improved 72-h survival (P = 0.02), reduced hepatic necrosis, attenuated sinusoidal vascular leakage, and suppressed systemic inflammatory cytokine production in KPLA mice. RNA-seq revealed activation of innate immune-sensing pathways during infection, which were markedly attenuated by argatroban. ZBP1 and PANoptosis-associated molecules were increased in KPLA livers and reduced by argatroban. ZBP1 was predominantly localized in hepatocytes. In KP-LPS-stimulated THLE-2 cells, RIPK3, ASC, and Caspase-8 showed enhanced intracellular co-localization, while co-immunoprecipitation demonstrated ZBP1 interactions with RIPK3, ASC, and Caspase-8. ZBP1 silencing markedly reduced KP-LPS-induced activation of p-MLKL, cleaved GSDMD, and cleaved caspase-3, supporting ZBP1-dependent PANoptosis as a key driver of hepatocyte inflammatory injury. Mechanistically, argatroban inhibited TLR4 endocytosis and downstream TBK1/IRF3-STAT1 signaling, thereby suppressing ZBP1 induction. CONCLUSIONS: Argatroban protects against KPLA-associated liver injury by inhibiting a TLR4 endocytosis-TBK1/IRF3-STAT1-ZBP1 axis and suppressing ZBP1-dependent PANoptosis, identifying PANoptosis as a potential therapeutic target in severe K. pneumoniae infection.