FIGURE 1.

Dex suppresses inflammatory signals via inhibition of posttranslational modifications of signaling mediators. (A) Effect of pretreatment (pre) versus cotreatment (co) with Dex on TLR ligand–mediated activation of inflammatory signals. Mouse peritoneal macrophages were pretreated (pre) with 100 nM of Dex for 3 h, followed by treatment with LPS (0.1 μg/ml), CpG (12.5 μg/ml), or poly(I:C) (50 μg/ml) for 30 min. In another set of experiments, cells were cotreated with Dex and individual TLR ligand for 30 min. (B) Effect of CHX treatment on Dex suppression of inflammatory signals. Macrophages were treated with 10 μM CHX for 45 min, followed by treatment with Dex for 3 h and subsequently with the individual TLR ligand for 30 min. WCL were analyzed by Western blot using anti–phospho-TAK1 (p-TAK1), total TAK1; anti–phospho-IκBα (p-IκBα), total IκBα; anti–phospho JNK (p-JNK), total JNK; anti–phospho p38 MAPK (p-p38) and total p38 MAPK (p38) Abs. Western blots were quantified by densitometric analyses. Abundance of phosphorylated proteins were normalized to total protein or β-actin, as appropriate. Protein expression in untreated, resting cells were considered as 1 U. The densitometry data presented are mean ± SD. Western blots are from a single experiment that are representative of three to four independent experiments. *p < 0.05 versus cells treated with respective TLR ligand.