Department of Pathology and Medical Biology, Laboratory of Allergology and Pulmonary Diseases, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands; GRIAC Research Institute, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
Allergy. 2013 Sep;68(9):1117-25. doi: 10.1111/all.12202. Epub 2013 Aug 5.
House dust mite (HDM) affects the immunological and physical barrier function of airway epithelium, leading to allergic sensitization, airway remodeling, and eosinophilic inflammation in mouse models, although the mechanisms are still largely unknown.
Given the implications for adenosine triphosphate (ATP)-dependent Ca(2+) signaling in allergic sensitization in mice, we sought to determine the role of intracellular Ca(2+) concentration (Ca(2+)) in HDM-induced barrier dysfunction and pro-inflammatory activity of bronchial epithelium.
We investigated the effect of HDM on accumulation of Ca(2+) levels, barrier function, and CCL20 release in human bronchial epithelial 16HBE cells and primary bronchial epithelial cells (PBECs) from healthy subjects and asthma patients. Involvement of ATP-dependent activation of purinergic receptors and downstream Ca(2+) influx was studied, using the ATP hydrolyzing agent apyrase, the purinergic receptor agonist PPADS, the calcium chelator BAPTA-AM, and calpain inhibitors.
Asthma PBECs were more susceptible to HDM-induced barrier dysfunction, CCL20 secretion, and Ca(2+) influx than healthy PBECs. Furthermore, we show that the HDM-induced increase in CCL20 in PBECs and 16HBE cells and the HDM-induced barrier dysfunction in 16HBE cells are dependent on Ca(2+) accumulation. Additionally, we demonstrate that Ca(2+) accumulation is initiated partly through the activation of purinergic receptors, which contributes to HDM-induced epithelial barrier dysfunction by disruption of cell-cell contacts, but not CCL20 secretion.
Our data show for the first time that Ca(2+) signaling plays a crucial role in barrier dysfunction and the pro-inflammatory response of bronchial epithelium upon HDM exposure and may thus have important implications for the development of allergic asthma.
屋尘螨（HDM）影响气道上皮的免疫和物理屏障功能，导致小鼠模型中的过敏致敏、气道重塑和嗜酸性粒细胞炎症，尽管其机制在很大程度上仍不清楚。
鉴于三磷酸腺苷（ATP）依赖性 Ca(2+) 信号在小鼠过敏致敏中的意义，我们试图确定细胞内 Ca(2+) 浓度 (Ca(2+)) 在 HDM 诱导的气道上皮屏障功能障碍和促炎活性中的作用。
我们研究了 HDM 对人支气管上皮 16HBE 细胞和来自健康受试者和哮喘患者的原代支气管上皮细胞（PBEC）中 Ca(2+) 水平、屏障功能和 CCL20 释放的影响。使用 ATP 水解酶 apyrase、嘌呤能受体激动剂 PPADS、钙螯合剂 BAPTA-AM 和钙蛋白酶抑制剂研究了 ATP 依赖性嘌呤能受体激活和下游 Ca(2+) 内流的作用。
与健康 PBEC 相比，哮喘 PBEC 对 HDM 诱导的屏障功能障碍、CCL20 分泌和 Ca(2+) 内流更为敏感。此外，我们表明，HDM 诱导的 PBEC 和 16HBE 细胞中 CCL20 的增加以及 16HBE 细胞中 HDM 诱导的屏障功能障碍依赖于 Ca(2+) 的积累。此外，我们证明 Ca(2+) 的积累部分是通过嘌呤能受体的激活启动的，这通过破坏细胞-细胞接触导致 HDM 诱导的上皮屏障功能障碍，但不导致 CCL20 分泌。
我们的数据首次表明，Ca(2+) 信号在 HDM 暴露后支气管上皮的屏障功能障碍和促炎反应中起关键作用，因此可能对过敏性哮喘的发展具有重要意义。
