ABSTRACT
We preliminarily investigated the role of NLRP3 inflammasome in Helicobacter pylori (H.pylori) Tipa-induced pro-inflammatory cytokines secretion in PMA-differentiated human acute monocytic leukemia cell line THP-1.PMA-differentiated THP-1 cells were treated with pure recombinant Tips protein.The secretion levels of TNF-α,IL-1β and IL-18 in supernatant of culture medium were detected by ELISA.Then we blocked MyD88/NF-κB and NLRP3/Caspase-1 pathways by PDTC or the general ROS scavenger,NAC,respectively,and determined the secretion levels of proinflammatory cytokines and the expression levels of NLRP3 and Caspase-1.The results showed that Tips protein can significantly induced the secretion of TNF-α,IL-1β and IL-18 in THP-1 cells in a time and dose-dependent manner.Levels of TNF-α,IL-1β and IL-18 approached their peaks at 6 h post-treatment by 40 μg/mL of Tipα protein (P＜0.05).Moreover,the blockade of NF-κB signaling pathway by PDTC can inhibit the secretion of proinflammatory cytokines and the expression of NLRP3 and Caspase-1.When THP-1 cells were pre-treated with ROS scavenger NAC,the Tipα-induced increased IL-1β and IL-18 secretion was obviously eliminated (P＜0.05),while TNF-α level had no significant difference,and the expression levels of Caspase-1 and NLRP3 also have a significant decrease.Our results demonstrated that Tipα can promote THP-1-drived macrophages to secrete proinflammatory cytokines TNF-α,IL-1β and IL-18,and the NLRP3/Caspase-1 pathway may be involved in the Tipα protein-induced IL-1β and IL-18 secretion.