Lappaconitine hydrobromide prevents NLRP3-GSDMD-mediated pyroptosis to alleviate sepsis-induced acute lung injury by enhancing NR1H3.

Evidence indicates that nuclear receptor subfamily 1 group H member 3 (NR1H3) activation mitigates sepsis-induced acute lung injury (SALI) by reducing inflammatory response. Nevertheless, the mechanisms underlying NR1H3-inflammation interactions in addressing SALI remain unclear. Moreover, limited phytochemicals have been documented to ameliorate SALI via this pathway. Here, we discovered that NR1H3 activation directly suppresses the clustering of toll-like receptor 4 (TLR4) to lipid rafts, which acts as a part of the priming of NLR family pyrin domain containing 3 (NLRP3) inflammasome. This process results in the suppression of NLRP3 inflammasome assembly and activation, consequently alleviating gasdermin-D (GSDMD)-mediated pyroptosis. Furthermore, through dual-luciferase reporter gene testing, drug binding assays, gene expression analysis, and biochemical evaluation, we determined lappaconitine hydrobromide (LAH) as a novel NR1H3 agonist that effectively suppresses TLR4-NLRP3 signaling pathway. Our results showed LAH attenuates inflammatory lung injury in both lipopolysaccharide (LPS) and cecal slurry (CS)-induced SALI mouse models.