The Role Of Jagged1 In Regulating Macrophage Function During Helicobacter Pylori Infection

BackgroundHelicobacter pylori(H.pylori)is the gram-negative bacteria,which mainly colonizes at gastric mucosa and is highly associated with the development of upper gastrointestinal diseases like gastritis,gastric ulcer,duodenal ulcer and gastric cancer.Macrophage(Mφ)is one of the critical immune cells for resisting H.pylori infection.Recent researches indicated that Notch signaling is vital in regulating the activation and the function of Mφ.However,the role of Notch in Mφ to eliminate H.pylori remains unclear.In this study,using a H.pylori-Mφ co-culture model,we found that the inhibition of Notch attenuated the secretion of inflammatory factors,phagocytosis,and bactericidal ability of Mφ against H.pylori.The expression profile in these activated Mφ induced by H.pylori,we identified Jagged1 as a potential regulator of Mφ to resist H.pylori infection.With up-regulation by plasmid and down-regulation by siRNA of Jagged1,we verified that Jagged1 promoted the function of Mcp against H.pylori infection.The addition of exogenous Jagged1 facilitated Mφ against H.pylori and the treatment of anti-Jagged1 antibody attenuated the antimicrobial activity of Mφ against H.pylori infection.These results demonstrated that Jagged1-Notch positively influenced the function of Mφ to eradicate H.pylori.PurposeTo explore the role of Jagged1 in regulating Mφ function against H.pylori,which will provide insight on the development of exploring Jagged1 as potentially therapeutic target for controlling H.pylori infection.Methods1.To analyze the effect of Notch signaling inhibition on the function of Mφ during H.pylori infection.2.To determine the key molecule of Notch components in modulating Mφ to eradicate H.pylori.3.To investigate the role of Jaggedl in modulating Mφ during H.pylori infection with the up-regulation and knockdown of Jagged1 and the treatment of recombinant Jagged1(rJagged1)and Jagged1 neutralizing antibody in Mφ.Results1.The inhibition of Notch signaling attenuated the differentiation into M1,the secretion of pro-inflammatory-associated factors,bactericidal ability of Mφ during H.pylori infection.2.qPCR and Western Blot showed that Jagged1 was up-regulated when Mφresisting H.pylori infection.3.The immunofluorescence showed the higher infiltration of Jagged1+ Mφ in the gastric mucosa of H.pylori+ gastritis patients.4.The up-regulation of Jagged1 strengthened the expression of iNOS,the secretion of pro-inflammatory cytokines,and the bactericidal ability of Mφ during H.pylori infection.And the siRNA knockdown of Jagged1 did the opposite.5.The exogenous recombinant Jagged1 protein facilitated the expression of iNOS,the secretion of pro-inflammatory cytokines,and the bactericidal ability of Mφ during H.pylori infection.6.The addition of Jagged1 blocking antibody suppressed the expression of iNOS,the secretion of pro-inflammatory cytokines,and the bactericidal ability of Mφ during H.pylori infection.ConclusionsIn vitro experiments showed that Jagged1 was upregulation and promoted the expression of iNOS,the secretion of pro-inflammatory cytokine,phagocytosis and bactericidal ability of Mφ during H.pylori infection.