Section of Respiratory Diseases, Department of Medical Sciences, University of Ferrara, Ferrara, Italy.
J Allergy Clin Immunol. 2013 Nov;132(5):1075-1085.e6. doi: 10.1016/j.jaci.2013.05.028. Epub 2013 Jul 18.
Although inhaled glucocorticoids are the mainstays of asthma treatment, they are poorly effective at treating and preventing virus-induced asthma exacerbations. The major viruses precipitating asthma exacerbations are rhinoviruses.
We sought to evaluate whether rhinovirus infection interferes with the mechanisms of action of glucocorticoids.
Cultured primary human bronchial or transformed (A549) respiratory epithelial cells were infected with rhinovirus 16 (RV-16) before dexamethasone exposure. Glucocorticoid receptor (GR) α nuclear translocation, glucocorticoid response element (GRE) binding, and transactivation/transrepression functional readouts were evaluated by using immunocytochemistry, Western blotting, DNA binding assays, real-time quantitative PCR, coimmunoprecipitation, and ELISA techniques. Specific inhibitors of c-Jun N-terminal kinase (JNK) and of IκB kinase (IKK) were used to investigate the involvement of intracellular signaling pathways.
RV-16 infection impaired dexamethasone-dependent (1) inhibition of IL-1β-induced CXCL8 release, (2) induction of mitogen-activated protein kinase phosphatase 1 gene expression, and (3) binding of GR to GREs in airway epithelial cells. This was associated with impaired GRα nuclear translocation, as assessed by means of both immunochemistry (54.0% ± 6.8% vs 24.7% ± 3.8% GR-positive nuclei after 10 nmol/L dexamethasone treatment in sham- or RV-16-infected cells, respectively; P < .01) and Western blotting. RV-16 infection induced nuclear factor κB activation and GRα phosphorylation, which were prevented by inhibitors of IKK2 and JNK, respectively. In rhinovirus-infected cells the combination of JNK and IKK2 inhibitors totally restored dexamethasone suppression of CXCL8 release, induction of mitogen-activated protein kinase phosphatase 1 gene expression, and GRα nuclear translocation.
RV-16 infection of human airway epithelium induces glucocorticoid resistance. Inhibition of RV-16-induced JNK and nuclear factor κB activation fully reversed rhinovirus impairment of both GRα nuclear translocation and the transactivation/transrepression activities of glucocorticoids.
虽然吸入性糖皮质激素是哮喘治疗的主要手段，但它们在治疗和预防病毒引起的哮喘恶化方面效果不佳。引发哮喘恶化的主要病毒是鼻病毒。
我们试图评估鼻病毒感染是否会干扰糖皮质激素的作用机制。
在暴露于地塞米松之前，用鼻病毒 16（RV-16）感染培养的原代人支气管或转化（A549）呼吸道上皮细胞。通过免疫细胞化学、Western blot、DNA 结合测定、实时定量 PCR、共免疫沉淀和 ELISA 技术评估糖皮质激素受体（GR）α核易位、糖皮质激素反应元件（GRE）结合和转导/转录抑制功能读数。使用 c-Jun N 末端激酶（JNK）和 IκB 激酶（IKK）的特异性抑制剂来研究细胞内信号通路的参与情况。
RV-16 感染削弱了地塞米松依赖性（1）抑制白细胞介素-1β诱导的 CXCL8 释放，（2）诱导丝裂原活化蛋白激酶磷酸酶 1 基因表达，以及（3）GR 与气道上皮细胞中 GRE 的结合。这与 GRα核易位受损有关，通过免疫化学（RV-16 感染或未感染细胞用 10 nmol/L 地塞米松处理后，GR 阳性核分别为 54.0%±6.8%和 24.7%±3.8%；P<.01）和 Western blot 评估。RV-16 感染诱导核因子 κB 激活和 GRα磷酸化，分别用 IKK2 和 JNK 的抑制剂可预防。在鼻病毒感染的细胞中，JNK 和 IKK2 抑制剂的联合使用完全恢复了地塞米松对 CXCL8 释放、丝裂原活化蛋白激酶磷酸酶 1 基因表达和 GRα核易位的抑制作用。
人类气道上皮细胞的 RV-16 感染诱导糖皮质激素抵抗。抑制 RV-16 诱导的 JNK 和核因子 κB 激活完全逆转了鼻病毒对 GRα核易位和糖皮质激素的转导/转录抑制活性的损害。
