REGULATION OF AIRWAY GOBLET CELL MUCIN RELEASE IN VITRO

气道粘液在肺中起着重要的防御作用。 其 功能主要由粘液的理化性质贡献 糖蛋白或粘蛋白。 粘蛋白由两种不同的细胞产生 型;杯状细胞在表面上皮和粘液细胞在 粘膜下腺体 杯状细胞粘蛋白的释放在某些 病理和毒性状态，但对其调控知之甚少 在正常情况下。 为了研究粘蛋白的调节 分泌，我们的实验室已经开发了一种体外模型的气道 杯状细胞 汇合的仓鼠气管表面上皮细胞 培养物高度富集气道杯状细胞， 形态学上通过凝集素结合特征，以及通过释放 高分子量粘蛋白样糖蛋白（MLGP）。 使用此 独特的文化体系，我们已经测试了大量的效果， 释放MLGP的药物。 我们发现细胞外ATP和ATP 类似物以浓度依赖性方式刺激MLGP释放。 ATP类似物对MLGP释放的相对效力及其 假定拮抗剂的抑制作用表明ATP的作用可能 由最近描述的P2型ATP受体介导，可能是 P2 y亚型。 这些数据表明，细胞外ATP可能参与 在正常情况下调节杯状细胞粘蛋白分泌。 我们建议通过以下方式扩展这一观察：（1）表征 推测的P2型ATP受体负责MLGP （2）阐明ATP诱导的细胞凋亡的生化机制。 MLGP释放;和（3）产生HTSE细胞ATP受体的抗体 为了进行免疫组织化学表征， 受体在正常和患病气道中的分布。 的 在这个项目中提出的实验将提高对 调节杯状细胞粘蛋白的释放在健康和疾病，提供了一个 开发能够控制粘液的新药理学试剂的方法 分泌，并提供了一个有价值的新系统的研究， 细胞外ATP的功能。

Airway mucus plays an important defensive role in the lung. Its function is contributed mainly by the physicochemical property of mucous glycoproteins or mucins. Mucins are produced by two different cell types; goblet cells in the surface epithelium and mucous cells in the submucosal glands. Goblet cell mucin release is stimulated in certain pathologic and toxic states, but little is known about its regulation under normal conditions. In order to study the regulation of mucin secreion, our laboratory has developed an in vitro model of the airway goblet cell. Confluent hamster tracheal surface epithelial cell cultures are highly enriched for airway goblet cells as judged morphologically by lectin binding characteristics, and by release of high molecular weight mucin-like glycoproteins (MLGP). Using this unique culture system, we have tested the effects of a large number of agents on MLGP release. We have found that extracellular ATP and ATP analogues stimulate MLGP release in a concentration-dependent fashion. The relative potency of ATP analogues for MLGP release and its inhibition by putative antagonists indicate that the action of ATP may be mediated by the recently described P2-type ATP receptor, likely the P2y subtype. These data suggest that extracellular ATP may be involved in the regulation of goblet cell mucin secreion under normal conditions. We propose to extend this observation by: (1) characterizing pharmacologically the putative P2-type ATP receptor responsible for MLGP release; (2) elucidating biochemical mechanisms involved in ATP-induced MLGP release; and (3) producing antibodies to the HTSE cell ATP receptor in order to perform immunohistochemical characterization of the distribution of the receptor in normal and diseased airways. The experiments proposed in this project will enhance understanding of the regulation of goblet cell mucin release in health and disease, provide a means of developing new pharmacologic agents that can control mucus secretion, and provide a valuable new system for the study of the function of extracellular ATP.