Luteolin Based On P2x7R-RAGE-TLR4 Axis To Regulate NLRP3-mediated HMGB1 Release In LPS-induced Liver Injury

Objectives:We focused to reveal a link between HMGB1 release and P2x7R-the receptor for advanced glycation end products(RAGE)-toll like receptor 4(TLR4)-mediated liver inflammation and the mechanism of luteolin based on P2x7R-RAGE-TLR4 axis to regulate NLRP3-mediated release of HMGB1 in LPS-induced liver injury.Materials and methods:We applied an in vivo model of LPS-induced mice liver injury and an in vitro model of LPS/ATP-stimulated macrophages or hepatocytes.Results:A severe liver injury was outbreak in LPS-administrated,characterized by an ascending lethality,alanine aminotransferase in serum and infiltration of immune cells,including neutrophils and macrophages.Additionally,HMGB1 was accumulated in both nucleus and cytoplasm of liver after LPS admonition,mice serum as well.Pharmacological inhibition of P2x7R-TLR4-RAGE-NLRP3 axis could modulate HMGB1 and IL-1β release in LPS/ATP-stimulated murine peritoneal macrophages.Interleukin 1 receptor antagonist(IL-1Ra)and interleukin 36 receptor antagonist(IL-36Ra)also reduced mature IL-1β and HMGB1 release.LPS/ATP stimulates the production and release of HMGB1 and caspase-1 activation in HepG2 cells,while inhibition of P2x7R-TLR4-RAGE-NLRP3 axis successfully blocked HMGB1 release and caspase-1 activation.Luteolin treatment reduced LPS-induced liver damage,reduced serum aminotransferase and inflammatory cell infiltration.Luteolin pretreatment might reduce macrophage and neutrophil aggregation.Luteolin inhibits the production and release of HMGB1 and the activation of caspase-1 in HepG2 cells stimulated by LPS/ATP.Conclusion:Collectively,regulation of the P2x7R-TLR4-RAGE-NLRP3 axis might regulate the release of HMGB1 both from macrophages and hepatocytes,thereby participating in the regulation of LPS-associated hepatic inflammation.Luteolin is based on the P2x7R-RAGE-TLR4-NLRP3 axis to regulate the release of HMGB1 to reduce liver inflammation caused by LPS.