Bungarus multicinctus Venom Triggers Microglial Pyroptosis via NLRP3/Caspase-1/GSDMD Pathway
Background
Pyroptosis is a highly pro-inflammatory form of programmed cell death, distinct from apoptosis, characterized by cell swelling, pore formation, and release of inflammatory mediators. It plays a critical role in various inflammatory diseases, including neuroinflammation. Microglia, the primary immune cells of the central nervous system, are central to neuroinflammatory responses. While some animal venoms are known to induce pyroptosis, the specific effects of Bungarus multicinctus (BM) venom, a potent neurotoxic snake venom, on microglial pyroptosis and subsequent neuroinflammation have been previously unknown. Understanding this mechanism could reveal novel targets for mitigating venom-induced neurological damage or inflammatory conditions.
Study Design
Researchers investigated the effects of Bungarus multicinctus (BM) venom on mouse BV2 microglia. Cells were exposed to varying doses of BM venom, and cellular viability was assessed. Pyroptosis markers, including NLRP3, GSDMD-N, and Caspase-1 p20 protein levels, were measured. Inflammatory responses were evaluated by quantifying mRNA transcripts of IL-1β, TNF-α, and IL-6, as well as secreted IL-1β and IL-18 via ELISA. Membrane damage, a hallmark of pyroptosis, was assessed by propidium iodide uptake. To confirm the pyroptotic mechanism, experiments included a pyroptosis inhibitor, disulfiram (5 μmol/L), and antivenom as control interventions.
Results
Exposure to Bungarus multicinctus (BM) venom resulted in a dose-dependent suppression of BV2 cellular viability. Concurrently, the venom significantly upregulated the protein levels of key pyroptosis-associated markers: NLRP3, GSDMD-N, and Caspase-1 p20. Furthermore, BM venom elevated the mRNA transcripts of pro-inflammatory cytokines IL-1β, TNF-α, and IL-6, while also stimulating the secretion of both IL-1β and IL-18. The venom also enhanced propidium iodide uptake, indicating substantial cell membrane damage consistent with pyroptosis. Importantly, these observed pyroptotic and inflammatory effects were significantly attenuated by both antivenom and the pyroptosis inhibitor disulfiram (5 μmol/L). This confirms the involvement of the NLRP3/Caspase-1/GSDMD pathway.
BM venom dose-dependently suppressed BV2 cell viability and upregulated
NLRP3,GSDMD-N, andCaspase-1 p20protein levels, alongside increasedIL-1β,TNF-α, andIL-6mRNA andIL-1β/IL-18secretion.
Key Findings
- Bungarus multicinctus venom dose-dependently suppressed BV2 microglial cell viability.
- Venom upregulated pyroptosis-associated proteins
NLRP3,GSDMD-N, andCaspase-1 p20. - Venom elevated mRNA transcripts of
IL-1β,TNF-α, andIL-6. - Venom stimulated the secretion of
IL-1βandIL-18. - Pyroptosis inhibitor disulfiram (5 μmol/L) attenuated these pyroptotic and inflammatory effects.
Why It Matters
This study provides crucial insights into the cellular mechanisms underlying Bungarus multicinctus venom toxicity, specifically its ability to induce microglial pyroptosis and neuroinflammation. Identifying the NLRP3/Caspase-1/GSDMD pathway as a key mediator offers potential therapeutic targets for mitigating the severe neurological damage associated with snake envenomation. For biohackers or clinicians interested in inflammation, this highlights pyroptosis as a distinct and potent inflammatory pathway that can be triggered by external toxins. While this is an in-vitro study, the finding that disulfiram, an existing drug, can attenuate these effects suggests a potential repurposing strategy or a starting point for developing novel anti-venom or neuroprotective agents that specifically target pyroptosis. Further research is needed to translate these findings into in-vivo models and ultimately clinical applications for snakebite management or other neuroinflammatory conditions.
bungarus multicinctus venom
pyroptosis
neuroinflammation
microglia
nlrp3
caspase-1
