Dex suppresses TLR3- and TLR9-mediated activation of p38 MAPK. Peritoneal macrophages were administered with Dex 3 hours before Poly (I:C) or CpG treatment. Cells were treated with Poly (I:C) or CpG for the indicated periods of time. Cell lysates were analyzed by Western blot using (A-B) anti–phospho-p38 MAPK (P-p38MAPK) and total p38 MAPK, (C-D) anti–phospho-ERK1/2 (P-ERK1/2) and total ERK1/2, and (E-F) anti–phospho-JNK (P-p46/p54) and total JNK (Total p46/p54) antibodies. Representative of 3 to 4 independent experiments. (G) Comparative effect of Dex on JNK activation by TLR3 and TLR9 ligands. Macrophages stimulated with Poly (I:C), CpG, or LPS for 30 minutes with or without Dex pretreatment. Cell lysates were analyzed by Western blot using anti–phospho-JNK (P-p46/p54) and total JNK (p46/p54) antibodies. Representative of 3 independent experiments.