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Figure 7 | BMC Molecular Biology

Figure 7

From: Glucocorticoids synergize with IL-1β to induce TLR2 expression via MAP Kinase Phosphatase-1-dependent dual Inhibition of MAPK JNK and p38 in epithelial cells

Figure 7

Inhibition of MKP-1 attenuates dexamethasone-mediated inhibition of IL-1β-induced p38 and JNK phosphorylation and enhancement of TLR2 expression. A, MKP-1 protein expression is induced by DEX and the MKP-1 induction is inhibited by Ro-31-8220, an inhibitor for MKP-1 expression, in HeLa cells. HeLa cells were first treated with Ro-31-8220 (10-6 M) for 2 h, and were then treated with DEX (10-6 M) for 2 h. Protein level of MKP-1 was assessed by Western blot analysis. β-Actin was used as a protein loading control. B, The inhibitory effect of DEX on IL-1β-induced p38 or JNK phosphorylation is antagonized by Ro-31-8220. HeLa cells were first treated with Ro-31-8220 (10-6 M) for 2 h and were then treated with DEX (10-6 M) for 2 h. The cells were stimulated with IL-1β (10 ng/ml) for 20 min. IL-1β-induced phosphorylation of p38 or JNK was then assessed by Western blot analysis. C, DEX-mediated enhancement of IL-1β-induced TLR2 expression is greatly inhibited by Ro-31-8220 in HeLa cells. HeLa cells were first treated with Ro-31-8220 (10-6 M) for 2 h and were then treated with DEX (10-6 M) for 2 h. The cells were stimulated with IL-1β (10 ng/ml) for 3 h, and the TLR2 mRNA levels were then assessed by real-time quantitative PCR. Values are the mean ± SD; n = 3. The symbols indicate results significantly different (p < 0.01) from unstimulated condition (*) and IL-1β-DEX-stimulated condition (without Ro-31-8220)(**). D, DEX-mediated enhancement of IL-1β-induced TLR2 expression is greatly inhibited by Ro-31-8220 in NHBE cells. NHBE cells were first treated with Ro-31-8220 (10-6 M) for 2 h and were then treated with DEX (10-6 M) for 2 h. The cells were stimulated 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-DEX-stimulated condition (without Ro-31-8220)(**). E, Overexpression of the antisense MKP-1 inhibited MKP-1 protein expression, but not MKP-2 or MKP-3 expression. Transfected HeLa cells were treated with DEX (10-6 M) for 2 h. Protein level of MKP-1, -2 and -3 were assessed by Western blot analysis. β-Actin was used as a protein loading control. F, Overexpression of antisense MKP-1 blocks the inhibitory effect of DEX on IL-1β-induced p38 or JNK phosphorylation in HeLa cells. Transfected HeLa cells were first pretreated with DEX (10-6 M) for 2 h. The cells were then stimulated with IL-1β (10 ng/ml) for 20 min. IL-1β-induced phosphorylation of p38 or JNK was next assessed by Western blot analysis. G, DEX-mediated enhancement of IL-1β-induced TLR2 expression is attenuated by overexpression of antisense MKP-1 in HeLa cells. Transfected HeLa cells were pretreated with DEX (10-6 M) for 2 h, and then stimulated 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-DEX-stimulated condition (without antisense MKP-1 construct)(**). H, DEX-mediated enhancement of IL-1β-induced TLR2 expression is also attenuated by overexpression of antisense MKP-1 in NHBE cells. Transfected cells werepretreated with DEX (10-6 M) for 2 h, and then stimulated 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-DEX-stimulated condition (without antisense MKP-1 construct)(**).

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