Department of Physiology, University of Arizona, Tucson, AZ, USA; Asthma and Airway Disease Research Center, University of Arizona, Tucson, AZ, USA; Bio5 Collaborative Research Institute, University of Arizona, Tucson, AZ, USA.
Asthma and Airway Disease Research Center, University of Arizona, Tucson, AZ, USA; Bio5 Collaborative Research Institute, University of Arizona, Tucson, AZ, USA; Department of Biochemistry, University of Arizona, Tucson, AZ, USA.
Biochem Biophys Res Commun. 2022 Feb 5;591:13-19. doi: 10.1016/j.bbrc.2021.12.090. Epub 2021 Dec 29.
Inhalation of the fungus Alternaria alternata is associated with an increased risk of allergic asthma development and exacerbations. Recent work in acute exposure animal models suggests that A. alternata-induced asthma symptoms, which include inflammation, mucus overproduction and airway hyperresponsiveness, are due to A. alternata proteases that act via protease-activated receptor-2 (PAR2). However, because other active components present in A. alternata may be contributing to asthma pathophysiology through alternative signaling, the specific role PAR2 plays in asthma initiation and maintenance remains undefined. Airway epithelial cells provide the first encounter with A. alternata and are thought to play an important role in initiating the physiologic response. To better understand the role for PAR2 airway epithelial signaling we created a PAR2-deficient human bronchial epithelial cell line (16HBEPAR) from a model bronchial parental line (16HBE14o-). Comparison of in vitro physiologic responses in these cell lines demonstrated a complete loss of PAR2 agonist (2at-LIGRL-NH) response and significantly attenuated protease (trypsin and elastase) and A. alternata responses in the 16HBEPAR line. Apical application of A. alternata to 16HBE14o- and 16HBEPAR2 grown at air-liquid interface demonstrated rapid, PAR2-dependent and independent, inflammatory cytokine, chemokine and growth factor basolateral release. In conclusion, the novel human PAR2-deficient cell line allows for direct in vitro examination of the role(s) for PAR2 in allergen challenge with polarized human airway epithelial cells.
吸入真菌交链格孢（Alternaria alternata）与过敏哮喘发展和恶化的风险增加有关。最近在急性暴露动物模型中的研究工作表明，交链格孢引起的哮喘症状包括炎症、黏液过度产生和气道高反应性，是由于交链格孢蛋白酶通过蛋白酶激活受体 2（PAR2）起作用。然而，由于交链格孢中存在的其他活性成分可能通过替代信号通路对哮喘病理生理学产生影响，因此 PAR2 在哮喘起始和维持中的具体作用仍未确定。气道上皮细胞提供了与交链格孢的首次接触，被认为在引发生理反应中起着重要作用。为了更好地理解 PAR2 气道上皮细胞信号在哮喘中的作用，我们从模型支气管亲本系（16HBE14o-）中创建了 PAR2 缺陷型人支气管上皮细胞系（16HBEPAR）。比较这些细胞系中的体外生理反应表明，PAR2 激动剂（2at-LIGRL-NH）反应完全丧失，并且在 16HBEPAR 系中显著减弱了蛋白酶（胰蛋白酶和弹性蛋白酶）和交链格孢的反应。将交链格孢施加到在气液界面上生长的 16HBE14o-和 16HBEPAR2 的顶端表明，快速、PAR2 依赖性和非依赖性炎症细胞因子、趋化因子和生长因子基底外侧释放。总之，新型人 PAR2 缺陷细胞系允许直接在体外检查 PAR2 在具有极化人气道上皮细胞的变应原挑战中的作用。
