Abstract：
Type 2 inflammation in asthma develops with exposure to stimuli to include inhaled allergens from house dust mites (HDM). Features include mucus hypersecretion and the formation of pro-secretory ion transport characterised by elevated basal Cl- current. Studies using human sinonasal epithelial cells treated with HDM extract report a higher protease activated receptor-2 (PAR-2) agonist-induced calcium mobilisation that may be related to airway sensitisation by allergen-associated proteases. Herein, this study aimed to investigate the effect of HDM on Ca2+ signalling and inflammatory responses in asthmatic airway epithelial cells. Primary bronchial epithelial cells (hPBECs) from asthma donors cultured at air-liquid interface were used to assess electrophysiological, Ca2+ signalling and inflammatory responses. Differences were observed regarding Ca2+ signalling in response to PAR-2 agonist 2-Furoyl-LIGRLO-amide (2-FLI), and equivalent short-circuit current (Ieq) in response to trypsin and 2-FLI, in ALI-asthma and healthy hPBECs. HDM treatment led to increased levels of intracellular cations (Ca2+, Na+) and significantly reduced the 2-FLI-induced change of Ieq in asthma cells. Apical HDM-induced Ca2+ mobilisation was found to mainly involve the activation of PAR-2 and PAR-4-associated store-operated Ca2+ influx and TRPV1. In contrast, PAR-2, PAR-4 antagonists and TRPV1 antagonist only showed slight impact on basolateral HDM-induced Ca2+ mobilisation. HDM trypsin-like serine proteases were the main components leading to non-amiloride sensitive Ieq and also increased interleukin-33 (IL-33) and thymic stromal lymphopoietin (TSLP) from asthma hPBECs. These studies add further insight into the complex mechanisms associated with HDM-induced alterations in cell signalling and their relevance to pathological changes within asthma.
摘要：
哮喘中的2型炎症随着暴露于刺激而发展，包括来自屋尘螨（HDM）的吸入过敏原。特征包括粘液分泌过多和以基础Cl-电流升高为特征的促分泌离子转运的形成。使用用HDM提取物处理的人鼻窦上皮细胞的研究报告了更高的蛋白酶激活受体2（PAR-2）激动剂诱导的钙动员，这可能与变应原相关蛋白酶的气道致敏有关。在这里，本研究旨在探讨HDM对哮喘气道上皮细胞Ca2+信号和炎症反应的影响。在气-液界面培养的哮喘供体的原代支气管上皮细胞（hPBECs）用于评估电生理，Ca2+信号传导和炎症反应。在响应PAR-2激动剂2-Furoyl-LIGRLO-酰胺（2-FLI）的Ca2信号传导方面观察到差异，以及响应胰蛋白酶和2-FLI的等效短路电流（Ieq），在ALI哮喘和健康的hPBECs中。HDM处理导致细胞内阳离子水平增加(Ca2+，Na）并显着降低了2-FLI诱导的哮喘细胞中Ieq的变化。发现根尖HDM诱导的Ca2动员主要涉及PAR-2和PAR-4相关的存储操作的Ca2流入和TRPV1的激活。相比之下,PAR-2、PAR-4拮抗剂和TRPV1拮抗剂仅显示对基底外侧HDM诱导的Ca2+动员的轻微影响。HDM胰蛋白酶样丝氨酸蛋白酶是导致非阿米洛利敏感Ieq的主要成分，也增加了哮喘hPBEC的白介素33（IL-33）和胸腺基质淋巴细胞生成素（TSLP）。这些研究进一步深入了解与HDM诱导的细胞信号改变相关的复杂机制及其与哮喘病理变化的相关性。
