BRONCHIOLAR CLARA CELLS: A ROLE IN TYPE 2 CELL FUNCTION

细支气管 CLARA 细胞：2 型细胞功能中的作用

• 批准号: 3344404
• 负责人: Kenneth Charles Palmer
• 金额: $ 9.77万
• 依托单位: WAYNE STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1984
• 资助国家: 美国
• 起止时间: 1984-09-01 至 1991-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3344404
• 关键词: adenoma; athymic mouse; bronchioles; cell cell interaction; cell growth regulation; cellular pathology; chemical related neoplasm /cancer; density gradient ultracentrifugation; histochemistry /cytochemistry; immunochemistry; laboratory mouse; lung alveolus; lung neoplasms; mixed tissue /cell culture; neoplasm /cancer transplantation; newborn animals; phospholipids; pulmonary surfactants; respiratory epithelium; secretion; unspecific monooxygenase

The nonciliated bronchiolar epithelial (Clara) cell of the lung remains a poor characterized cell with respect to its physiologic role in the airway. A major barrier to elucidation of the Clara cell's functional significance in the lung is the great difficulty encountered in obtaining sufficient quantities of these cells for study. During the current grant period, our laboratory has developed a unique approach to this problem by establishing and characterizing an ethylnitrosourea-induced (ENU) murine lung adenoma model, whose cells possess most of the structural and known biochemical features attributed to the normal mouse Clara cell. These include ultrastructural features consistent with normal mouse Clara cells, beta-adrenergic regulation of secretion, enhanced mixed function oxidase activity, unique lectin binding patterns and preliminary evidence of shared antigens with normal Clara cells. Morphological investigations of this model clearly indicated the occurrence of a cell-cell interaction between the Clara cells of the adenoma and alveolar Type 2 cells adjacent to the tumors. Specifically, the Type 2 cells were stimulated to accumulate large quantities of surfactant-like material. This Type 2 cell alteration only occurred in relation to Clara cell adenomas and appeared directly related to age and size of the tumors. The studies detailed in this revised renewal proposal are designed to test the hypothesis that the bronchiolar Clara cell has a defined functional interaction with alveolar Type 2 cells by modulating Type 2 cell surfactant metabolism via product(s) synthesized and secreted by Clara cells. Three major approaches to testing this hypothesis are described. The first is to establish an in vitro system to allow more controlled studies of the postulated cell-cell interactions. This will be accomplished by using freshly isolated alveolar Type 2 cells or the A549 cell line that will be cocultured with Clara cells isolated from ENU-induced pulmonary adenomas. The second approach will use an alternative in vivo bioassay for the effects of Clara cell secretory product(s) using pleural implants of Clara cell tumors and/or cells in newborn or immunologically deficient nude mice. This model will reduce some of our concerns over possible alteration of parenchymal Type 2 cells by the original carcinogenic exposure. Finally, we intend to isolate, purify and biochemically characterize the composition of the Clara cell secretory product(s) and, using our existing antisera to Clara cell antigen, to define the antigenic, molecular, and functional character of the secretory substances. The application of our mouse lung Clara cell adenoma model to these long range goals offer a new and unique approach to define the Clara cell role in physiological and pathological conditions in the lung.

肺的无纤毛细支气管上皮（Clara）细胞 仍然是一个差的表征细胞方面，其生理 在气道中的作用。 澄清克拉拉的主要障碍 细胞在肺中的功能意义是很大的困难 在获得足够数量的这些细胞， study. 在目前的资助期内，我们的实验室 开发了一种独特的方法来解决这个问题， 表征乙基亚硝基脲诱导的（ENU）鼠肺 腺瘤模型，其细胞具有大部分的结构和已知的 正常小鼠Clara细胞的生化特征。 这些包括与正常小鼠一致的超微结构特征 克拉拉细胞，β-肾上腺素能分泌调节，增强 混合功能氧化酶活性，独特的凝集素结合模式， 与正常克拉拉细胞共享抗原的初步证据。 该模型的形态学研究清楚地表明， Clara细胞之间的细胞-细胞相互作用的发生 腺瘤和与肿瘤相邻的肺泡2型细胞。 具体地说，2型细胞被刺激以积累大量的 大量的类表面活性物质。 2型细胞 仅发生与Clara细胞腺瘤相关的改变， 与年龄和肿瘤大小直接相关。 本修订更新建议中详述的研究旨在 为了验证细支气管Clara细胞具有 与肺泡2型细胞的功能性相互作用， 通过产品调节2型细胞表面活性剂代谢 由克拉拉细胞合成和分泌。 三个主要的方法来检验这一假设进行了说明。 一是建立体外系统，让更多 假设的细胞间相互作用的对照研究。 这 将通过使用新鲜分离的肺泡2型 细胞或A549细胞系，其将与Clara共培养 从ENU诱导的肺腺瘤中分离的细胞。 第二种方法将使用另一种体内生物测定法， Clara细胞分泌产物对胸膜炎的影响 Clara细胞肿瘤和/或新生儿或 免疫缺陷裸鼠。 这种模式会减少一些 我们对2型脑实质可能改变的担忧 原致癌物暴露的细胞。 最后，我们打算分离，纯化和生化 表征Clara细胞分泌产物的组成 利用我们现有的Clara细胞抗原的抗血清， 分泌型的抗原、分子和功能特征 物质. 我们的小鼠肺Clara细胞腺瘤模型的应用， 长期目标提供了一个新的和独特的方法来定义 克拉拉细胞在生理和病理条件下的作用 肺。