FIGURE 6.

The effect of COX-2 inhibition on the ROS production and inflammatory cytokines expression of macrophages. (A) COX-2 inhibition did not affect macrophage ROS production. RAW264.7 macrophages treated with COX-2 inhibitor NS398 or DMSO vehicle, were infected with ExPEC XM O2:K1:H7 at MOI 10. At 6 h and 9 h after ExPEC XM O2:K1:H7 infection, ROS levels of RAW264.7 macrophages were determined with the Reactive Oxygen Species Assay Kit. (B,C) COX-2 inhibition did not affect the expression of inflammatory cytokines IL-6 and TNF-α but increased that of anti-inflammatory cytokines IL-10. RAW264.7 macrophages were treated with COX-2 inhibitor NS398 or DMSO vehicle, at 6 h and 9 h after ExPEC XM O2:K1:H7 infection at MOI 10, the cells and supernatants were then harvested for RNA extraction and ELISA assay. The mRNA and protein levels of IL-6, TNF-α, and IL-10 were determined by qRT-PCR and ELISA kits. qRT-PCR results were normalized to the housekeeping gene GAPDH. Data is shown as the mean ± SEM and represents the results from three independent experiments (**P < 0.01, ***P < 0.001, ****P < 0.0001).