FIGURE 6.

Effect of MKP-1 targeting siRNA on dexamethasone-dependent repression of p38 MAPK phosphorylation. A, BEAS-2B cells were incubated with control or MKP-1-specific siRNAs for 24 h prior to stimulation with dexamethasone for 1 h. Cells were then harvested for protein and subjected to Western blot analysis for MKP-1 and GAPDH. Blots representative of 10 such experiments are shown. Following densitometric analysis, data (n = 10), normalized to GAPDH, were expressed as a percentage of dexamethasone-stimulated cells and plotted as means ± S.E. B, BEAS-2B cells were incubated with siRNAs as in A and then pretreated with dexamethasone for the times indicated prior to stimulation with TNFα (10 ng/ml) for 15 min. Cells were then harvested and subjected to Western blot analysis for phospho-p38 (P-p38) and GAPDH. Blots representative of six such experiments are shown.