1 Département de Pharmacologie and.
Am J Respir Crit Care Med. 2015 Mar 1;191(5):538-46. doi: 10.1164/rccm.201409-1582OC.
Asthma is a frequent airway disease, and asthma control determinants have been associated with indoor allergen sensitization. The most frequent allergens are house dust mites (HDM), which act in vivo on the bronchial epithelial layer. Severe asthma has also been associated with bronchial remodeling and more specifically with increased mass of bronchial smooth muscle (BSM). However, the relationship between HDM stimulation of the bronchial epithelial layer and BSM remodeling is unknown.
To evaluate whether epithelial stimulation with HDM induces BSM cell proliferation in subjects with severe asthma.
A total of 22 subjects with severe asthma and 27 subjects with no asthma were recruited. We have developed an in vitro culture model combining an epithelium layer in air-liquid interface (ALI) interacting with BSM. We assessed BSM proliferation using BrdU incorporation. We explored the role of epithelium-derived mediators using reverse-transcriptase polymerase chain reaction (RT-PCR) and ELISA in vitro and in vivo. Finally, leukotrienes receptor expression was assessed in vitro by flow cytometry and RT-PCR and ex vivo by laser microdissection and RT-PCR.
We found that epithelial stimulation by HDM selectively increased the proliferation of asthmatic BSM cells and not that of nonasthmatic cells. The mechanism involved epithelial protease-activated receptor-2-dependent production of leukotrienes C4 associated with an overexpression of leukotrienes receptor CysLTR1 by asthmatic BSM cells in vitro and ex vivo.
This work demonstrates the selective role of HDM on BSM remodeling in patients with severe asthma and points out different therapeutic targets at epithelial and smooth muscle levels.
哮喘是一种常见的气道疾病，哮喘控制决定因素与室内过敏原致敏有关。最常见的过敏原是屋尘螨（HDM），它在体内作用于支气管上皮层。重度哮喘也与支气管重塑有关，特别是与支气管平滑肌（BSM）质量增加有关。然而，HDM 刺激支气管上皮层与 BSM 重塑之间的关系尚不清楚。
评估 HDM 对重度哮喘患者的支气管上皮细胞刺激是否会引起 BSM 细胞增殖。
共招募了 22 名重度哮喘患者和 27 名无哮喘患者。我们开发了一种体外培养模型，将气液界面（ALI）中的上皮层与 BSM 结合在一起。我们通过 BrdU 掺入来评估 BSM 增殖。我们通过体外和体内的逆转录聚合酶链反应（RT-PCR）和 ELISA 探索了上皮细胞衍生介质的作用。最后，通过流式细胞术和 RT-PCR 体外评估白细胞三烯受体表达，并通过激光微切割和 RT-PCR 进行离体评估。
我们发现 HDM 对上皮细胞的刺激选择性地增加了哮喘患者 BSM 细胞的增殖，而不是非哮喘患者的增殖。该机制涉及上皮蛋白酶激活受体-2 依赖性白细胞三烯 C4 的产生，与哮喘患者 BSM 细胞体外和离体的白细胞三烯受体 CysLTR1 的过度表达有关。
这项工作证明了 HDM 在重度哮喘患者 BSM 重塑中的选择性作用，并指出了上皮细胞和平滑肌水平上不同的治疗靶点。
