Figure 5.

Leukotriene C₄ (LTC₄) activates ERK1/2 and p38 MAPK in dendritic cells (DCs). (a) DCs (3 × 10⁶ cells per 500 μl complete medium) were prewarmed for 30 min at 37°. Cells were incubated in the presence or absence of LPS (1 μg/ml) for 30 min at 37° and then treated or not with 0.01 μm LTC₄ for 5 min at 37°. The samples were analysed by Western blotting as described in the Materials and methods. Pervanadate-treated DCs (0.1 mm orthovanadate plus 0.3 mm H₂O₂ for 10 min at 37°) were used as positive phosphorylation controls. Western blots are representative of five experiments. (b) and (c) Histograms of ratio obtained by quantitative densitometric analysis of P-p38 and ERK1/2; respectively, normalized with β-actin densitometric units. The bars represent the mean ± SEM of five experiments. Asterisk represents statistical significance (*P ≤ 0.05) versus CT and # represents significance (^#P ≤ 0.05) versus LPS.