First Department of Medicine, Tokyo Women's Medical University School of Medicine, Shinjuku-ku, Tokyo, Japan.
Allergol Int. 2012 Mar;61(1):133-42. doi: 10.2332/allergolint.11-OA-0307.
Human Ca(2+)-activated Cl ion channel 1 (hCLCA1) is expressed in goblet cell hyperplasia in the airway of asthmatics, and murine CLCA3 is associated with antigen-sensitized and IL-13-induced goblet cell metaplasia in mice. However, the role of CLCA in goblet cell degranulation is not fully investigated. Niflumic acid (NFA), a relatively specific CLCA inhibitor, inhibits goblet cell metaplasia, but the effect of NFA on goblet cell degranulation has not been determined in an asthma model.
Guinea pigs were sensitized with ovalbumin (OA) twice and then challenged with saline, OA, histamine, and one of the Ca(2+)-dependent secretagogues, UTP. The PAS/AB-stained mucus area in the tracheal epithelium was measured with a computer image analysis system, and the morphology of mucus granules was examined by transmission electron microscopy. In the in vitro experiment, goblet cells cultured with IL-13 at the air-liquid interface were stimulated with UTP in the presence or absence of NFA, and the MUC5AC level in cell lysates was measured by ELISA.
The mucus areas were smaller in the OA-, histamine-, and UTP-challenged animals than in the saline-challenged animals. NFA inhibited the decrease in mucus area and morphological changes in mucus granules. UTP caused swelling and exocytosis of mucus granules and MUC5AC secretion by cultured goblet cells, and NFA inhibited these changes.
NFA inhibited the secretory response of mucus granules in an asthma model, suggesting that CLCA may be associated with goblet cell degranulation and that CLCA inhibitors may be useful for the treatment of hypersecretion in asthma.
人类 Ca(2+)-激活 Cl 离子通道 1（hCLCA1）在哮喘患者气道中的杯状细胞增生中表达，而鼠类 CLCA3 与抗原致敏和 IL-13 诱导的小鼠杯状细胞化生有关。然而，CLCA 在杯状细胞脱颗粒中的作用尚未得到充分研究。尼氟酸（NFA）是一种相对特异性的 CLCA 抑制剂，可抑制杯状细胞化生，但在哮喘模型中，NFA 对杯状细胞脱颗粒的影响尚未确定。
豚鼠用卵清蛋白（OA）两次致敏，然后用生理盐水、OA、组胺和一种 Ca(2+)-依赖性分泌激动剂 UTP 进行挑战。用计算机图像分析系统测量气管上皮中 PAS/AB 染色的粘液面积，并通过透射电子显微镜检查粘液颗粒的形态。在体外实验中，用 IL-13 在气液界面培养杯状细胞，在存在或不存在 NFA 的情况下用 UTP 刺激，通过 ELISA 测量细胞裂解物中的 MUC5AC 水平。
OA、组胺和 UTP 挑战后的动物的粘液面积小于生理盐水挑战后的动物。NFA 抑制了粘液面积的减少和粘液颗粒的形态变化。UTP 引起培养的杯状细胞中粘液颗粒的肿胀和胞吐作用以及 MUC5AC 的分泌，NFA 抑制了这些变化。
NFA 抑制了哮喘模型中粘液颗粒的分泌反应，表明 CLCA 可能与杯状细胞脱颗粒有关，CLCA 抑制剂可能对哮喘的高分泌治疗有用。
