ABSTRACT
Aim To explore the influences of scutellarin on ATP-induced NLRP3 inflammasome activation and pyroptosis,using LPS-primed murine macrophages J774A.1 as an inflammatory cell model,and to explore the underlying mechanism.Methods The effects of scutellarin on ATP-induced pyroptosis in murine J774A.1 macrophages were analyzed by propidium iodide (PI) staining assay.The levels of IL-1β,caspase-1 and HMGB1 in cell lysates and culture supernatants were analysed using Western blot.The levels of IL-1β in cell culture supernatants were measured by cytometric beads array (CBA).Results ATP significantly induced caspase-1 activation and mature IL-1β and HMGB1 release into the culture supernatants in LPS-primed murine J774A.1 macrophages,and induced pyroptosis.Scutellarin treatment dose-dependently inhibited ATP-induced caspase-1 activation,mature IL-1β and HMGB1 release,and pyroptosis.Notably,scutellarin's inhibitory effects on ATP-induced pyroptosis were markedly reversed by the adenylate cyclase inhibitor MDL12330A and selective protein kinase A (PKA) inhibitor H89.Conclusion Scutellarin inhibits NLRP3 inflammasome activation and pyroptosis by modulating the PKA activity in macrophages,thereby exhibiting anti-inflammatory activities.