Persistent activation of nuclear factor-κB signaling pathway in severe uncontrolled asthma
Persistent activation of nuclear factor-κB signaling pathway in severe uncontrolled asthma
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DOI：
10.1164/rccm.200205-479oc
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发表时间：
2003-11-15
影响因子：
24.7
通讯作者：
Vignola, AM
中科院分区：
文献类型：
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作者：
Gagliardo, R;Chanez, P;Vignola, AM
转录因子核因子-kappaB(NF-kappaB)与其抑制蛋白IkappaBalpha结合后失活。在炎症信号的刺激下，IkappaBalpha被IkappaB激酶磷酸化，随后被降解。释放的核因子-kappaB可诱导粒细胞-巨噬细胞集落刺激因子、白介素8等细胞因子的表达，并在激活后调节正常T细胞的表达和分泌。这些介质在哮喘中过度表达，并通过核因子-kappaB活性抑制被糖皮质激素下调。然而，尽管持续全身糖皮质激素治疗，重症哮喘患者外周血中分离的单个核细胞仍能释放高水平的粒细胞-巨噬细胞集落刺激因子和白细胞介素8，并在激活后调节正常T细胞的表达和分泌。我们报道，这些介质显著减少了吡咯烷二硫代氨基甲酸酯，一种核因子-kappaB激活的抑制剂。为了进一步研究重症哮喘患者中持续的核因子-kappaB活性，我们分析了这一激活途径的各个组成部分在健康受试者和轻度控制、中度和重度未控制疾病的哮喘患者中的表达。我们发现了三组哮喘患者体内大量的磷酸化IkappaBalpha。免疫印迹分析显示，中、重度哮喘患者外周血单核细胞中IkappaB激酶β和p65水平均高于正常人。电泳迁移率改变分析和免疫细胞化学显示，重度哮喘患者p65处于较高的激活状态。我们的数据表明，在严重哮喘中，过度激活的核因子-kB使炎症介质的产生永久化。
The transcription factor nuclear factor-kappaB (NF-kappaB) is inactive when bound to its inhibitory protein IkappaBalpha. On cell stimulation with inflammatory signals, IkappaBalpha is phosphorylated by IkappaB kinases and subsequently degraded. Freed NF-kappaB then induces expression of cytokines such as granulocyte-macrophage colony-stimulating factor, interleukin-8, and regulated upon activation, normal T cell expressed and secreted. These mediators are overexpressed in asthma and are downregulated by glucocorticoids through NF-kappaB activity repression. However, high levels of granulocyte-macrophage colony-stimulating factor, interleukin-8, and regulated upon activation, normal T cell expressed and presumably secreted are released by peripheral blood mononuclear cells isolated from patients with severe asthma despite continuous systemic glucocorticold treatment. We report that these mediators are markedly decreased by pyrrolidinedithiocarbamate, an inhibitor of NF-kappaB activation. To further characterize the persistent NF-kappaB activation in severe asthma, we analyzed the expression of various components of this activation pathway in healthy subjects and in asthmatics with mild controlled, and moderate and severe uncontrolled disease. We found high amounts of phosphorylated IkappaBalpha characterizing the three asthmatic groups. Western blot analyses indicated that in peripheral blood mononuclear cells the IkappaB kinase beta and p65 levels were greater in moderate and severe asthmatics than in normal subjects. Electrophoretic mobility shift assay and immunocytochemistry showed a greater activation status of p65 in severe asthmatics. Our data suggest that exaggerated NF-KB activation perpetuates inflammatory mediators production in severe asthma.