Fig. 1

Activation of NLRP3 inflammasome. The activation of NLRP3 inflammasome requires two signals. Priming signal: TLRs are activated by extracellular DAMPs or PAMPs and mediate translocation of NF-κB, finally resulting in increased expression of NLRP3, pro-caspase-1, pro-IL-1β, and pro-IL-18. Activation signal: NLRP3 activated by stimuli like MSU and particulate matters activate, recruiting ASC and pro-caspase-1, then forming into inflammasome and releasing mature caspase-1. Caspase-1 cleaves pro-IL-1β, pro-IL-18, and GSDMD into mature form, contributing to further inflammation. TLR, Toll-like receptor; DAMP, Damage-associated molecular pattern; PAMP, Damage-associated molecular pattern; MSU, monosodium urate; GSDMD, Gasdermin D