Inhibition of the Caspase-9/GSDME axis by Auranofin: a potential therapeutic strategy for bacterial toxin-mediated...

Bacterial toxin-mediated severe systemic diseases, such as Shiga toxin-induced hemolytic uremic syndrome (HUS), are associated with an exceptionally high mortality rate due to life-threatening multi-organ failure and a profound inflammatory surge. Despite this severe clinical burden, targeted therapeutic drugs remain unavailable. Here, we investigated the therapeutic potential of Auranofin (AUR), an FDA-approved compound, in mitigating systemic lethality by targeting the Caspase-9/GSDME-mediated cell death axis. Utilizing a high-throughput screening of 2819 FDA-approved drugs, we identified AUR as a potent inhibitor of Stx2-induced cytotoxicity in THP-1 macrophages. In vitro, AUR pre-treatment (2.5 μM) significantly preserved cell viability, stabilized mitochondrial membrane potential, and suppressed the release of pro-inflammatory IL-1β and LDH. Mechanistic analysis revealed that AUR abrogated the activation of Caspase-9 and Caspase-3, effectively blocking GSDME-mediated pyroptosis. In a C57BL/6 mouse model of Stx2-induced systemic injury, AUR administration significantly prolonged survival time and ameliorated renal and intestinal dysfunction. Histological evaluation confirmed that AUR reduced renal tubular necrosis, fibrin deposition, and the infiltration of macrophages and neutrophils. Western blot analysis of kidney tissues further corroborated the inhibition of the Caspase-9/GSDME axis in vivo. Our findings elucidate that AUR represents a promising drug-repurposing strategy for treating severe systemic syndromes by intercepting the crosstalk between apoptosis and pyroptosis, highlighting a novel, translational therapeutic paradigm for acute toxemia.