Abstract: Objective To study the impact of Helicobacter pylori(H.pylori) infection on NLRP3 inflammasome associated proteins expression and activation in gastric epithelial cells and gastric cancer cells, and further discuss the role of NLRP3 inflammasome when gastric cells were infected by H.pylori. Methods The gastric epithelial cell line GES-1 and gastric cancer cell line MKN-45 were infected by H.pylori NCTC11639 at a multiplicity of infection(MOI)of 100 or 200. At 6 h or 12 h after infection, the cells were harvested and the total proteins were extracted. Then the expressions of NLRP3 and Caspase-1 were analyzed by Western blotting and the level of IL-1β secretion was detected by ELISA. Results The expressions of NLRP3 and Caspase-1 and the secretion of IL-1β were increased with the increase of NCTC11639 MOI in GES-1 cells(P<0.05). Although the expression of NLRP3 was increased, the expression of Caspase-1 and the secretion of IL-1β were decreased with the increase of NCTC11639 MOI in MKN-45 cells(P<0.05). In addition, the expressions of NLRP3 and Caspase-1 and the secretion of IL-1β were not significantly different in GES-1 or MKN-45 infected by H.pylori for 6 h and 12 h with the same MOI(P>0.05). Conclusion H.pylori infection promotes the expressions and activations of NLRP3, Caspase-1 and IL-1β in gastric epithelial cells. However, H.pylori infection facilitates the expression of NLRP3 but inhibits the expressions and activations of Caspase-1 and IL-1β in gastric cancer cells.

Key words: Helicobacter pylori, Caspase-1, NLRP3, IL-1β