H89, an inhibitor of PKA and MSK, inhibits cyclic-AMP response element binding protein-mediated MAPK phosphatase-1 induction by lipopolysaccharide
H89, an inhibitor of PKA and MSK, inhibits cyclic-AMP response element binding protein-mediated MAPK phosphatase-1 induction by lipopolysaccharide
复制标题
DOI：
10.1007/s00011-009-0057-z
复制
发表时间：
2009-12-01
影响因子：
6.7
通讯作者：
Kim, Sang Geon
中科院分区：
文献类型：
--
作者：
Cho, Il Je;Woo, Na Ri;Kim, Sang Geon
脂多糖(LPS)通过MAPK途径刺激炎性细胞因子的产生和免疫应答的放大。MAPK磷酸酶(MKPs)反馈调节MAPK的活性，以防止过度的免疫功能。H89已被用作蛋白激酶A(PKA)、有丝分裂原和应激激活蛋白激酶(MSK)通路的抑制剂。鉴于PKA和MSK在MKP-1诱导中的潜在作用以及H89抑制这些激酶的能力，本研究探讨了H89对内毒素诱导的MKP-1的影响以及环-AMP反应元件结合蛋白(CREB)在MKP-1诱导中的作用。H89处理可抑制Raw264.7细胞MKP-1蛋白和mRNA水平的升高以及内毒素诱导的基因转录。免疫印迹、凝胶漂移和染色质免疫沉淀实验表明，内毒素激活CREB，H89对CREB有抑制作用，提示H89‘S抑制CREB可能影响MKP-1的诱导。此外，H89还阻止了内毒素诱导其他MKP基因(DUSP-2、4、8和16)的能力。使用MAPK抑制剂的实验表明，MAPKs参与了CREB的磷酸化和MKP-1的诱导，提示CREB介导的MKP-1的诱导在一定程度上是MAPK的反馈抑制环。我们的结果表明，H89抑制了CREB的激活和内毒素对CREB介导的MKP-1的诱导，这可能是其抑制PKA和MSK的结果。
Lipopolysaccharide (LPS) stimulates the production of inflammatory cytokines and the amplification of immune responses via MAPK pathways. MAPK phosphatases (MKPs) feedback-regulate the activities of MAPKs to prevent excessive immunological functions. H89 has been used as an inhibitor of the protein kinase A (PKA) and mitogen- and stress-activated protein kinase (MSK) pathways. In view of the potential roles of PKA and MSK for MKP-1 induction and the ability of H89 to inhibit these kinases, this study examined the effect of H89 on MKP-1 induction by LPS and the role of cyclic-AMP response element binding protein (CREB) in the MKP-1 induction.H89 treatment inhibited increases in MKP-1 protein and mRNA levels, and gene transcription by LPS in Raw264.7 cells. Immunoblot, gel-shift, and chromatin-immunoprecipitation assays showed the activation of CREB by LPS, and the ability of H89 to inhibit it, suggesting that H89's inhibition of CREB may affect MKP-1 induction. In addition, H89 prevented the ability of LPS to induce other MKP genes (Dusp-2, 4, 8, and 16). Experiments using MAPK inhibitors showed that MAPKs are involved in CREB phosphorylation and MKP-1 induction, suggesting that CREB-mediated MKP-1 induction serves in part as a feedback-inhibitory loop of MAPKs.Our results demonstrate that H89 inhibits the activation of CREB and the CREB-mediated MKP-1 induction by LPS, which may result from its inhibition of PKA and MSK.