气道上皮细胞ATP释放在周期性压力所致气道黏液分泌中的作用

目的探讨气道上皮细胞三磷酸腺苷（ATP）的释放及胞内钙离子（Ca2＋）在周期性压力波所致气道黏液分泌中的作用。方法体外培养人支气管上皮细胞株16HBE,通过节律性倾斜细胞培养板,利用液体的表面张力、大气压及液体重力所产生的牵张力（剪应力）及压力（压应力）给予细胞机械刺激。根据对培养细胞所施加条件不同分为对照组、单纯倾斜组、倾斜＋Ca2＋螯合剂BAPTA-AM组、倾斜＋Ca2＋螯合剂EGTA组和倾斜＋P2Y受体阻断剂RB-2组。分别采用四甲基偶氮唑盐（MTT）法测定各组细胞存活率,反转录聚合酶链反应（RT-PCR）检测各组黏蛋白（MUC）5AC mRNA表达水平,ELISA法检测细胞培养上清液中MUC5AC蛋白含量,高效液相色谱法（HPLC）检测培养液中ATP释放量,倒置荧光显微镜观察细胞内Ca2＋浓度变化。结果与对照组相比,单纯倾斜组16HBE细胞MUC5AC mRNA和蛋白的表达量及细胞培养上清液中ATP的含量均明显升高（P〈0.05）;倾斜＋BAPTA-AM组、倾斜＋RB-2组ATP及MUC5AC蛋白表达量均明显低于单纯倾斜组（P〈0.05）;倾斜＋EGTA组和倾斜＋RB-2组MUC5AC mRNA表达量与单纯倾斜组比较,差异无统计学意义（P〉0.05）。结论节律性压力可刺激气道黏膜上皮MUC5AC分泌,其机制与依赖Ca2＋的ATP释放密切相关;该机制中的Ca2＋几乎全部由胞内存储钙提供。

Role of ATP release in cyclic pressure-induced mucin excretion in airway epithelial cells

Objective To investigate the role of adenosine triphosphate(ATP) release and intra-cellular calcium ion(Ca2+) on cyclic pressure-induced mucin(MUC) excretion in airway epithelial cells. MethodsHuman bronchial epithelial cell line 16HBE cultured in vitro were stimulated mechanically through tilting the culture dish,and the shear stress and compressive stress were provided by liquid surface tension,atmospheric pressure and liquid gravity.The airway epithelial cells were divided into control group,tilt group,t...