Figure 2. Aryl hydrocarbon receptor (AhR) and Nox2 are necessary for PMs-induced down-regulation of filaggrin and COX2/ PGE2 expression in HaCaT cells.

Cells were pre-incubated with AhRI (an AhR antagonist) (0.1, 1, 10 μM) for 1 h and then exposed with PMs (50 μg/cm²) for 24 h. (A) Effects of AhRI (an AhR antagonist) on COX2 expression (open bars) and PGE2 release (shaded bars) were determined by Western blotting and ELISA as described in Fig. 1. (B–D) Effects of siRNAs of AhR, Nox2 (gp91^phox) and p47^phox on filaggrin and COX2 protein expression and PGE2 release. (A–D) Data are expressed as mean ± standard error of the mean, based on three independent experiments. ^*P < 0.05, ^#P < 0.01, compared with basal levels.