NEUTROPHIL INFLAMMASOME ACTIVATION AND PYROPTOSIS INDUCED BY A METALLOPROTEINASE VIA HIF-1α AND GASDERMIN D PATHWAYS

Bothrops jararacussu venom contains snake venom metalloproteinases (SVMPs) that contribute to inflammation and tissue damage. BjussuMP-II, a PI-class SVMP, lacks hemorrhagic activity but retains proteolytic and immunomodulatory properties. Here, we uncover a previously unrecognized function of BjussuMP-II in triggering NLRP3 inflammasome activation in human neutrophils, leading to IL-1β release and pyroptosis. This discovery reveals a direct molecular link between SVMP activity and inflammasome-mediated inflammation, a fundamental mechanism with implications beyond snakebite pathology, and highlights inflammasomes as potential therapeutic targets to mitigate severe inflammatory responses in envenomed patients. Mechanistically, BjussuMP-II increased expression of NLRP3, ASC, CASPASE-1, NEK7, and HIF-1α, as well as IL-1β and Gasdermin D (GSDMD) cleavage, confirmed by immunoblotting and immunofluorescence. It promoted the release of IL-1β, LTB4, LDH, and dsDNA, consistent with pyroptosis, which was reduced by MCC950 or disulfiram. Studies in Gsdmd⁻/⁻ and HIF-1α-deficient neutrophils further demonstrated the requirement of these pathways for cytokine release. Collectively, these results indicate that BjussuMP-II modulates inflammasome-associated signaling pathways in neutrophils, contributing to the inflammatory responses triggered by snake venom metalloproteinases.