MUCINS ON THE SURFACE OF CULTURED AIRWAY GOBLET CELLS

衬在气道腔表面的粘液作为主要的 物理化学屏障的主机，其粘弹性的改变， 性质导致异常的粘膜纤毛清除，这导致各种 肺部疾病。 粘液的粘弹性是 主要由分泌的粘液糖蛋白或粘蛋白贡献 由两种类型的气道细胞;表面上皮的杯状细胞 和粘膜下腺体的粘液细胞。 多年来我 一直致力于调节杯状细胞粘蛋白释放， 良好表征的体外模型系统，原代仓鼠气管 表面上皮（HTSE）细胞培养系统。 我最近发现 有一些粘蛋白样糖蛋白（MLGP）紧密结合到 汇合HTSE细胞的顶面。 根据初步数据， 已经提出了一些假设，即一些杯状细胞粘蛋白是（i） 锚定在顶端细胞表面，和（ii）由MUC 1粘蛋白编码 基因，和（iii）可能受G蛋白偶联的调节 磷脂酶C和蛋白激酶C。我打算验证这些假设 通过：（i）从质膜鉴定和纯化MLGP， 进一步表征化学结构和物理化学性质， （ii）确定这些MLGP是否是 由MUCI粘蛋白基因编码;和（iii）确定这些细胞是否 表面MLGP可以通过已经显示引起 从这些细胞中释放粘蛋白。 从这些得到的结果 实验将是至关重要的，考虑到这些 数百万道尔顿的糖蛋白 物理化学性质被锚定到杯的顶端表面 细胞，其与腔内容物直接接触。 因此这些 细胞表面粘蛋白可能在细菌粘附中起关键作用， 上皮细胞损伤各种管腔内容物和肺部药物 递送，特别是用于患有以下疾病的患者的基因治疗： 囊性纤维化或肺气肿。 另一方面，我们对 这些细胞表面粘蛋白将帮助我们更好地了解 健康和疾病中的气道杯状细胞。

Mucus lining the airway luminal surface serves as a primary physicochemical barrier for the host, and alterations of its viscoelastic property results in abnormal mucociliary clearance which leads to various pulmonary diseases. The viscoelastic property of the mucus is contributed mainly by mucous glycoproteins or mucins which are secreted by two types of airways cells; the goblet cells of the surface epithelium and the mucous cells of the submucosal gland. Over the years, I have been working on the regulation of the goblet cell mucin release using a well-characterized in vitro model system, a primary hamster tracheal surface epithelial (HTSE) cell culture system. I have recently found that there are some mucin-like glycoproteins (MLGP) tightly bound to the apical surface of confluent HTSE cells. Based on preliminary data, the hypotheses have been developed that some goblet cell mucins are (i) anchored on the apical cell surface, and (ii) encoded by MUC1 mucin gene(s), and (iii) possibly regulated by the G protein-coupled phospholipase C and protein kinase C. I propose to test these hypotheses by: (i) identifying and purifying MLGP from the plasma membrane and further characterizing the chemical structure and the physicochemical properties of these MLGP; (ii) determining whether or not these MLGP are encoded by MUCI mucin genes; and (iii) determining whether these cell surface MLGP can be released by agents which have been shown to provoke mucin release from these cells. The result obtained from these experiments will be crucially important considering that these multimillion dalton glycoproteins with the extremely complex physicochemical property are anchored to the apical surface of the goblet cells, which are in direct contact with the luminal content. Thus, these cell surface mucins may play crucial roles in bacterial adhesion, epithelial cell injuries to various luminal contents, and pulmonary drug delivery, especially for gene therapy for patients suffering from either cystic fibrosis or emphysema. On the other hand, our understanding of these cell surface mucins will help us better understand the role of airways goblet cells in health and disease.