Protein phosphatase 5 mediates corticosteroid insensitivity in airway smooth muscle in patients with severe asthma.
Protein phosphatase 5 mediates corticosteroid insensitivity in airway smooth muscle in patients with severe asthma.
复制标题
蛋白质磷酸酶5介导严重哮喘患者气道平滑肌的皮质类固醇不敏。
作者：
Chachi L;Abbasian M;Gavrila A;Alzahrani A;Tliba O;Bradding P;Wardlaw AJ;Brightling C;Amrani Y
重症哮喘患者对糖皮质激素（GC）不敏感的机制仍不明确。近期有证据表明，由于GC受体（GRα）功能缺陷，气道平滑肌（ASM）中存在对GC不敏感的信号通路。我们探究了是否还有其他机制可以解释重症哮喘患者ASM细胞对GC敏感性降低的现象。
对健康受试者和重症哮喘患者的ASM细胞用肿瘤坏死因子α（TNFα）进行处理，通过酶联免疫吸附试验（ELISA）、免疫印迹、免疫组化及实时聚合酶链反应（PCR），比较两组细胞对皮质类固醇的反应。采用免疫组化和流式细胞术检测支气管内活检组织及ASM细胞中蛋白磷酸酶PP5的表达情况。
与健康受试者相比，重症哮喘患者的ASM细胞经TNFα刺激后产生的趋化因子CCL11和CCL5，对氟替卡松和地塞米松均不敏感。与健康受试者的反应相比，氟替卡松诱导的GRα核转位、丝氨酸211位点的磷酸化以及糖皮质激素诱导的亮氨酸拉链蛋白（GILZ）的表达，在重症哮喘患者的ASM细胞中均显著降低。重症哮喘患者ASM细胞中的PP5水平升高，而利用小干扰RNA（siRNA）敲低PP5后，氟替卡松对趋化因子生成的抑制作用及其诱导GRα核转位和糖皮质激素反应元件（GRE）依赖的GILZ表达的能力得以恢复。在体内，重症哮喘患者支气管内活检组织的ASM束中PP5的表达也有所增加。
PP5依赖的GRα功能受损是导致重症哮喘患者ASM对GC不敏感的一种新机制。
The mechanisms driving glucocorticoids (GC) insensitivity in patients with severe asthma are still unknown. Recent evidence suggests the existence of GC insensitive pathways in airway smooth muscle (ASM) caused by a defect in GC receptor (GRα) function. We examined whether other mechanisms could potentially explain the reduced sensitivity of ASM cells to GC in severe asthmatics. ASM cells from healthy and severe asthmatic subjects were treated with TNFα and responses to corticosteroids in both cohorts were compared by ELISA, immunoblot, immunohistochemistry and real time PCR. Immunohistochemistry and flow cytometry assays were used to assess the expression of the protein phosphatase PP5 in endobronchial biopsies and ASM cells. The production of CCL11 and CCL5 by TNFα was insensitive to both fluticasone and dexamethasone in ASM cells from severe asthmatic compared to that in healthy subjects. Fluticasone-induced GRα nuclear translocation, phosphorylation at serine 211 and expression of Glucocorticoid-induced leucine zipper (GILZ) was significantly reduced in ASM cells from severe asthmatics compared to responses in healthy subjects. Levels of PP5 were increased in ASM cells from severe asthmatics and PP5 knockdown using siRNA restored fluticasone repressive action on chemokine production and its ability to induce GRα nuclear translocation and GRE-dependent GILZ expression. In vivo PP5 expression was also increased in the ASM bundles in endobronchial biopsies in severe asthmatics. PP5-dependent impairment of GRα function represents a novel mechanism driving GC insensitivity in ASM in severe asthma.
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影响因子：
3.7
作者：
Kobayashi Y;Mercado N;Barnes PJ;Ito K
通讯作者：
Ito K
DOI：
10.1164/rccm.200603-394oc
发表时间：
2006-12-01
影响因子：
24.7
作者：
Kaur, Davinder;Saunders, Ruth;Brightling, Christopher E.
通讯作者：
Brightling, Christopher E.
影响因子：
4.8
作者：
Hinds, Terry D., Jr.;Stechschulte, Lance A.;Sanchez, Edwin R.
通讯作者：
Sanchez, Edwin R.
DOI：
10.1164/rccm.200507-1046oc
发表时间：
2006-03-15
影响因子：
24.7
作者：
Goleva, E;Li, LB;Leung, DYM
通讯作者：
Leung, DYM
DOI：
10.4049/jimmunol.1300104
发表时间：
2013-09-01
期刊：
Journal of immunology (Baltimore, Md. : 1950)
影响因子：
--
作者：
Chachi L;Shikotra A;Duffy SM;Tliba O;Brightling C;Bradding P;Amrani Y
通讯作者：
Amrani Y