All-Trans Retinoic Acid Enhances Bacterial Flagellin-Stimulated Proinflammatory Responses in Human Monocyte THP-1 Cells by Upregulating CD14

Figure 2

Effect of RARα, RXRα agonist, or antagonist on NF-κB/AP-1 activity of THP-1 cells upon flagellin challenge. To determine RAR/RXR agonist effects, THP1-XBlue cells were treated with 1 μM RARα agonist BMS753 (a) or 1 μM RXRα agonist LG100268 (b) for 24 h and then treated with different concentrations of flagellin as indicated above for 24 h to determine RAR/RXR antagonist effects; cells were preincubated with 1 μM RARα antagonist BMS195614 (a) or RXRα antagonist UVI3003 (b) for 2 h and then treated with 1 μM ATRA or DMSO for 24 h followed by stimulation with different concentrations of flagellin from S. typhimurium as indicated above for 24 h. Secreted alkaline phosphatase in cell culture supernatants was measured by ELISA to determine NF-κB/AP-1 activity. Bar graphs indicate relative NF-κB/AP-1 activity ± SD. Statistical significance was assessed by one-way ANOVA using SPSS. .

(a)

(b)