Inflammatory response of macrophages cultured with Helicobacter pylori strains was regulated by miR-155.

MicroRNA-155 plays an important role in the inflammatory response macrophages, while present studies identified that miR-155 was up-expressed in gastritis induced by Helicobacter pylori. We found that miR-155 was over expressed in macrophages infected with H. pylori in vivo or in vitro. Subsequently, inflammatory cytokines IL-23, IL-10, TNF-α and IL-8 were increased significantly, and the expression of CD80, CD86 or COX2, NOS2. Were enhanced in H. pylori infection macrophages by regulated with miR-155mimics. Furthermore, the apoptosis of macrophages induced by H. pylori was increased obviously due to the over-expression of miR-155. Therefore, these observations indicated that miR-155 may act as a inflammatory promoter in H. pylori infected macrophages. These findings contribute us to understand the functions of miR-155 in gastritis induced by H. pylori furtherly.