Endothelin-1-Induced Macrophage Inflammatory Protein-1β Expression in Monocytic Cells Involves Hypoxia-Inducible Factor-1α and AP-1 and Is Negatively Regulated by microRNA-195
Endothelin-1-Induced Macrophage Inflammatory Protein-1β Expression in Monocytic Cells Involves Hypoxia-Inducible Factor-1α and AP-1 and Is Negatively Regulated by microRNA-195
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DOI：
10.4049/jimmunol.1000660
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发表时间：
2010-11-15
影响因子：
4.4
通讯作者：
Kalra, Vijay K.
中科院分区：
文献类型：
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作者：
Gonsalves, Caryn;Kalra, Vijay K.
镰状细胞病 (SCD) 患者表现出慢性炎症状态，表现为白细胞增多和促炎细胞趋化因子循环水平升高。我们的研究表明，SCD 中胎盘生长因子水平较高，并且胎盘生长因子诱导肺微血管内皮细胞释放血管收缩剂内皮素-1 (ET-1)。在这项研究中，我们观察到 ET-1 增加了趋化因子 MIP-1 beta 或 CCL4 的表达。 ET-1 诱导 THP-1 细胞和人外周血单核细胞中的 MIP-1 β mRNA 表达是通过激活 PI3K、NADPH 氧化酶、p38 MAPK 和 JNK-1 而不是 JNK-2 来实现的。 ET-1 诱导的 MIP-1 β 表达涉及缺氧诱导因子 1 α (HIF-1 α)，与缺氧无关，如用 HIF-1 α 小干扰 RNA 沉默、EMSA 和染色质免疫沉淀分析所证明。当近端 MIP-1 β 启动子 (-1053/+43 bp) 中的五个缺氧反应元件、AP-1 或 NF-κ B 结合基序中的任何一个发生突变时，ET-1 诱导的 MIP-1 β 启动子荧光素酶活性减弱。此外，ET-1 显着下调关键 microRNA microRNA-195a 的表达，该 microRNA-195a 在 MIP-1 beta mRNA 的 3' 非翻译区显示出互补的结合位点。此外，在表达 microRNA-195a 后，THP-1 细胞或外周血单核细胞中 ET-1 诱导的 MIP-1 β mRNA 表达减少。相反，用抗 microRNA-195a 寡核苷酸转染单核细胞可使 ET-1 诱导的 MIP-1 β 表达增加数倍。总而言之，这些研究表明，ET-1 介导的 MIP-1 β 基因表达通过其启动子中的缺氧反应元件、AP-1 和 NF-κ B 顺式结合元件进行调节，并受到 microRNA-195 的负向调节，该 microRNA-195 靶向 MIP-1 β RNA 的 3' 非翻译区。这些研究提供了我们认为基于 HIF-1 α 和 microRNA 靶点的改善 SCD 炎症的新途径。免疫学杂志，2010，185：6253-6264。
Patients with sickle cell disease (SCD) exhibit a chronic inflammatory state manifested by leukocytosis and increased circulating levels of proinflammatory cytochemokines. Our studies show that placenta growth factor levels are high in SCD, and placental growth factor induces the release of the vasoconstrictor endothelin-1 (ET-1) from pulmonary microvascular endothelial cells. In this study, we observed that ET-1 increased the expression of the chemokines MIP-1 beta or CCL4. ET-1-induced MIP-1 beta mRNA expression in THP-1 cells and human peripheral blood monocytes occurred via the activation of PI3K, NADPH oxidase, p38 MAPK, and JNK-1 but not JNK-2. ET-1-induced MIP-1 beta expression involved hypoxia-inducible factor-1 alpha (HIF-1 alpha), independent of hypoxia, as demonstrated by silencing with HIF-1 alpha small interfering RNA, EMSA, and chromatin immunoprecipitation analysis. ET-1-induced MIP-1 beta promoter luciferase activity was attenuated when any of the five hypoxia-response elements, AP-1, or NF-kappa B binding motifs in the proximal MIP-1 beta promoter (-1053/+43 bp) were mutated. Furthermore, ET-1 significantly downregulated the expression of a key microRNA, microRNA-195a, which showed a complementary binding site in the 3' untranslated region of MIP-1 beta mRNA. Moreover, ET-1-induced MIP-1 beta mRNA expression in either THP-1 cells or peripheral blood monocytes was reduced upon expression of microRNA-195a. Conversely, transfection of monocytes with anti-microRNA-195a oligonucleotide augmented several-fold ET-1-induced MIP-1 beta expression. Taken together, these studies showed that ET-1-mediated MIP-1 beta gene expression is regulated via hypoxia-response elements, AP-1, and NF-kappa B cis-binding elements in its promoter and negatively regulated by microRNA-195, which targets the 3' untranslated region of MIP-1 beta RNA. These studies provide what we believe are new avenues, based on targets of HIF-1 alpha and microRNAs, for ameliorating inflammation in SCD. The Journal of Immunology, 2010, 185: 6253-6264.