Dex induction of MKP-1 expression is the major GR target for suppression of p38 MAPK phosphorylation. (A) Effect of Dex on MKP-1 induction in control and MGRKO macrophages treated with LPS for the indicated periods of time. (B) Effect of triptolide on p38 MAPK phosphorylation in the presence and absence of Dex. Representative of 2 to 3 independent experiments.