Necrosulfonamide ameliorates intestinal inflammation via inhibiting GSDMD-medicated pyroptosis and MLKL-mediated necroptosis

Inflammatory bowel disease (IBD) is a chronic relapsing disorder of the gastrointestinal tract, while the present therapeutic efficacy is insufficient. In recent years, numerous studies have shown that necrosulfonamide (NSA) played a protective role in many inflammatory diseases by blocking mixed lineage kinase domain-like protein (MLKL) polymerization. However, the protective effect of NSA in dextran sodium sulfate (DSS)-induced colitis has not been reported. In the present study, we used DSS to establish mouse models of acute colitis to explore the proactive effect of NSA. Our study showed that NSA alleviated symptoms of DSS-induced colitis through reducing weight loss and disease activity index (DAI) score. Furthermore, NSA inhibited macrophages and CD4+/CD8 + T-cell accumulation in colon tissue caused by DSS. In addition, we found that NSA had the therapeutic effects on DSS-induced colitis. Mechanistically, we detected the expression level of phosphorylated MLKL, the release of LDH, cytokines, and N-gasdermin D (N-GSDMD) to examine necroptosis and pyroptosis pathways. We found NSA alleviated the severity of DSS-induced colitis by inhibiting the expressions of phosphorylated MLKL and N- GSDMD in vivo. In vitro experiments, we found NSA inhibited the release of inflammatory factors and LDH and the expressions of N-GSDMD in bone marrow-derived macrophages. Furthermore, we found NSA inhibited the expression of phosphorylated MLKL and necroptosis of NCM460 cell through western blot and flow cytometer. In general, this study reveals that NSA inhibits pyroptosis and necroptosis pathways to eventually alleviate intes-tinal inflammation, which may serve as a potential candidate for IBD therapy.