Figure 3

Activation of MKK3/6-p38 α/β MAPK pathway is negatively involved in IL-1β-induced TLR2 expression. A, IL-1β induces p38 phosphorylation in HeLa cells in a time-dependent manner as assessed by Western blot analysis. Cells were treated with IL-1β (10 ng/ml) for the indicated time periods. B, SB203580 greatly enhances IL-1β-induced TLR2 up-regulation in HeLa cells. Cells were pretreated for 2 h with the indicated concentration of SB203580 prior to treatment with IL-1β (10 ng/ml) for 3 h. Values are the mean ± SD; n = 3. The symbols indicate results significantly different (p < 0.01) from unstimulated condition (*) and IL-1β-stimulated condition (without SB203580)(**). C, Overexpression of a dominant-negative mutants of either p38α [fp38α(AF)] or p38β [fp38β (AF)] enhances, whereas overexpression of a wild-type p38α or p38β reduces, the IL-1β-induced TLR2 expression in HeLa cells. Cells were treated with IL-1β (10 ng/ml) for 3 h. Values are the mean ± SD; n = 3. The symbols indicate results significantly different (p < 0.01) from unstimulated condition (*) and IL-1β-stimulated condition (without wild-type or dominant-negative construct)(**). D, SB203580 greatly enhances IL-1β-induced TLR2 up-regulation in NHBE cells. Cells were pretreated for 2 h with SB203580 (20 μM) prior to treatment with IL-1β (10 ng/ml) for 3 h. Values are the mean ± SD; n = 3. The symbols indicate results significantly different (p < 0.01) from unstimulated condition (*) and IL-1β-stimulated condition (without SB203580)(**). E, Overexpression of a dominant-negative mutant of p38α or p38β enhances the IL-1β-induced TLR2 expression in NHBE cells. Values are the mean ± SD; n = 3. The symbols indicate results significantly different (p < 0.01) from unstimulated condition (*) and IL-1β-stimulated condition (without dominant negative construct)(**). F, IL-1β induces MKK3/6 phosphorylation in HeLa cells. Cells were treated with IL-1β (10 ng/ml) for 20 min. G, Overexpression of a dominant-negative mutant form of either MKK3 [MKK3b (A)] or MKK6 [MKK6b (A)] also enhances IL-1β-induced TLR2 up-regulation in HeLa cells. Cells were treated with IL-1β (10 ng/ml) for 3 h. Values are the mean ± SD; n = 3. The symbols indicate results significantly different (p < 0.01) from unstimulated condition (*) and IL-1β-stimulated condition (without dominant-negative construct)(**). H, Overexpression of a dominant-negative mutant form of either MKK3 or MKK6 also enhances IL-1β-induced TLR2 up-regulation in NHBE cells. Cells were treated with IL-1β (10 ng/ml) for 3 h. Values are the mean ± SD; n = 3. The symbols indicate results significantly different (p < 0.01) from unstimulated condition (*) and IL-1β-stimulated condition (without dominant-negative construct)(**).