ABSTRACT
AIM: To study the roles of Toll-like receptor 4 ( TLR4 ) and TLR4 activator lipopolysaccharide ( LPS) in colonic inflammation recovery .METHODS:Normal intestinal epithelial cells were cultured with LPS in vitro. The subgroups of the intestinal epithelial cells with differential expression of TLR 4 ( low, normal and high ) were construc-ted by the technique of lentivirus transfection .The cells with normal and high expression of TLR 4 were induced by LPS for 0 h, 2 h and 4 h.Inflammatory cytokines TNF-α, IL-6 and IL-8 in the culture supernatant were detected by ELISA .The mRNA levels of TNF-α, IL-6, IL-8, IL-10 and IL-1βwere detected by qPCR .The cell mobility was also monitored by wound healing assay .RESULTS:The protein expression of TLR 4 was significantly higher after LPS treatment than that in control groups of both cells with TLR4 normal and high expression (P<0.05).The inflammatory cytokines TNF-α, IL-6, IL-8 and IL-1βat mRNA and protein levels were also significantly increased after LPS treatment compared with control group (P<0.05).The protein levels of TNF-α, IL-6 and IL-8 between the 2 groups were also different with statistical sig-nificance ( P<0.05 ) .Higher mobility was observed in the cells with TLR 4 high expression compared to control cells . CONCLUSION:LPS induction might play a role in the activation of TLR 4-mediated inflammatory pathways by up-regula-ting the expression of inflammatory cytokines at both transcriptional and translational levels .