FIG 12.

MAPK-specific inhibitors significantly inhibit the production of proinflammatory cytokines/chemokines by BMDCs. BMDCs derived from wild-type mice were pretreated with SB203580 at 10 μM (inhibitor for p38), PD98059 at 20 μM (inhibitor for Erk), U0126 at 20 μM (inhibitor for MEK1/2), or SP600125 at 40 μM (inhibitor for JNK) for 30 min, followed by exposure to TcdB (200 ng/ml) for 5 h. Controls included cells treated with inhibitors only, TcdB only, or PBS (medium). Supernatants were collected, and levels of IL-6, KC, and TNF-α were determined. The results presented are representative of three independent experiments (n = 3). Bars stand for means; error bars, standard deviations. Asterisks indicate significant differences (**, P < 0.01) between results with TcdB alone and results with TcdB plus inhibitors.