151. Helicobacter pylori activates gastric epithelial cells to produce interleukin-8 via protease-activated receptor 2
- Author
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Hirokazu, Kajikawa, Norimasa, Yoshida, Kazuhiro, Katada, Fumihiro, Hirayama, Osamu, Handa, Satoshi, Kokura, Yuji, Naito, and Toshikazu, Yoshikawa
- Subjects
Serine Proteinase Inhibitors ,Helicobacter pylori ,Interleukin-8 ,Gene Expression ,Epithelial Cells ,Transfection ,Guanidines ,Antibodies ,Benzamidines ,Helicobacter Infections ,Gastric Mucosa ,Cell Line, Tumor ,Humans ,Receptor, PAR-2 ,RNA, Small Interfering - Abstract
Recently, it has been shown that serine proteases derived from microorganisms stimulate epithelial cells to produce inflammatory mediators through protease-activated receptor (PAR). We investigated the involvement of PAR2 in the interleukin (IL)-8 production by Helicobacter pylori-infected gastric epithelial cells.Human gastric epithelial cells, MKN45 cells, were used. The expression of PAR2 was assessed by real-time PCR and immunocytochemistry, and IL-8 protein was measured by an enzyme-linked immunosorbent assay. PAR2 mRNA and protein were constitutively expressed on unstimulated MKN45 cells. The treatment of cells with H. pylori resulted in a significant increase in PAR2 expression. In addition, trypsin (a natural PAR2 agonist), SLIGKV amide (a synthetic PAR2 agonist), H. pylori live bacteria or H. pylori culture supernatant significantly induced IL-8 production from MKN45 cells. H. pylori-induced IL-8 production was inhibited by nafamostat mesilate (a serine protease inhibitor), neutralizing antibody to PAR2 and in PAR2-deficient cells treated with siRNA.These results reveal that H. pylori-derived protease activates gastric epithelial cells to produce inflammatory cytokines through PAR2, suggesting an important role for PAR2 in the modulation of gastric inflammation associated with H. pylori.
- Published
- 2007