Figure 6.

Effect of p38 MAPK pathway modulation on GR-mediated transactivation activities in S203A-transfected cells. Top: Cells were cotransfected for 48 hours with 2 μg of pcDNA3 empty vector or GR S203A mutant and 2 μg luciferase reporter plasmid driven by GRE motifs and 1 μg of β-galactosidase vector (A) and/or 100 nM p38 MAPK siRNA or control siRNA (B) and/or 2 μg MKK3 construct or the corresponding empty vector (C). Cells were pretreated with FP (100 nM) for 2 hours (A–C) and/or SB203580 (10 μM) for 1 hour before FP addition (A). Cells were lysed, and the luciferase activity was measured as described in Materials and Methods. The results are expressed as RLU. Data are representative of three separate experiments. Bottom: Cells were cotransfected for 48 hours with 2 μg of pcDNA3 empty vector or GR S203A mutant (A) and/or 100 nM p38 MAPK siRNA or control siRNA (B) and/or 2 μg MKK3 construct or the corresponding empty vector (C). Cells were treated as above. Total mRNA was analyzed by real-time PCR. The values indicate expression of the steroid-inducible gene, GILZ, normalized to GAPDH mRNA levels and are presented relative to the expression of basal cells, which was set as 1. Data are representative of three separate experiments. *P < 0.05 compared with untreated cells (A) or with siRNA control–transfected cells (B) or with empty vector–transfected cells (C). **P < 0.01 compared with untreated cells (A) or with siRNA control–transfected cells (B) or with empty vector–transfected cells (C). ^#P < 0.05 compared with empty vector–transfected cells left untreated (C). ^δP < 0.05 compared with empty vector–transfected cells treated with FP alone (C). NS = not significant.