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: 3344408
• 负责人: Kenneth Charles Palmer
• 金额: $ 5.42万
• 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 1987-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3344408
• 关键词: adenoma; bronchioles; cell cell interaction; cellular oncology; chemical related neoplasm /cancer; density gradient ultracentrifugation; disease /disorder model; histochemistry /cytochemistry; lung alveolus; lung neoplasms; mixed tissue /cell culture; model design /development; phospholipids; pulmonary surfactants; respiratory epithelium; secretion; unspecific monooxygenase

The nonciliated bronchiolar epithelial (Clara) cell of the lung remains an enigma, particularly with respect to its biological role in the small airway and proximal alveoli. A major barrier to identifying tha Clara cell's functional activity is the great difficulty encountered in obtaining significant quantities of these cells for study. In an effort to develop a unique approach to this problem area, we have recently established a murine lung adenoma model in our laboratory -- induced by transplacental exposure to N,ethylnitrosourea. With appropriate manipulation, we have been able to produce benign tumors of the lung that are primarily of Clara cells origin. Our preliminary morphologic studies have confirmed the structural characteristics of thse cells as being those of the murine Clara cell. During our initial investigations, we observed the development of unusual Type 2 cells in the immediate vicinity of Clara cell tumors. These abnormal Type 2 cell accumulate abundant quantities of surfactant-like phospholipid material in cytoplasmic vacuoles. These appear to be directly related to the age and size of the Clara cell tumor -- the older and larger the tumor becames, the more extensive the inclusions per cell and total number of Type 2 cells involved. The studies outlined in this proposal are designed to test the hypothesis that the bronchiolar Clara cell has a defined functional interaction with alveolar epithelial cells; specifically, the modulation of Type 2 cell surfactant synthesis/secretion via a product produced by Clara cells. The major areas of Clara cell biology will be examined. The first involves the isolation, purification and functional characterization of cells obtained from our tumor model. These cells will be examined in the isolated state for biocemical features such as mixed-function oxidase activity, lipid degrading activity (phospholipases), the chemical compositions of their secretory granules and identification of some of the factors regulating synthesis and release of these secretions. The second approach will attempt to develop optimum conditions for maintaining isolated Clara cells in cutlure. Then to establish co-cultures of Clara cells with freshly isolated rat lung Type 2 cells, the A549 human lung cell line, and if necessary, virus transformed rat lung Type 2 cells in an effort to reproduce the Type 2 cell effects we have observed in vivo. The application of the mouse lung Clara cell adenoma model is a unique approach to testing the proposed hypothesis.

肺的无纤毛细支气管上皮（Clara）细胞仍然是一个 谜，特别是关于其在小生物中的生物作用， 气道和近端肺泡。 确认克拉拉身份的主要障碍 细胞的功能活性是获得 大量的这些细胞用于研究。 为了开发一个 针对这一问题的独特方法，我们最近建立了一种小鼠 经胎盘暴露法建立肺腺瘤模型 N，乙基亚硝基脲。 通过适当的操作，我们已经能够 产生主要由Clara细胞构成的肺良性肿瘤 起源 我们初步的形态学研究证实了 这些细胞的特征与鼠Clara细胞的特征相同。 在我们最初的调查中，我们观察到了 Clara细胞瘤附近的2型细胞。 这些 异常的2型细胞积累大量的表面活性剂样 细胞质空泡中的磷脂物质。 这些似乎是直接 与克拉拉细胞瘤的年龄和大小有关， 肿瘤变得越大，每个细胞的内含物和总内含物越多， 涉及的2型细胞数量。 本提案中概述的研究旨在验证这一假设 细支气管Clara细胞与 肺泡上皮细胞;特别是，2型细胞的调节 通过Clara细胞产生的产物合成/分泌表面活性剂。 克拉拉细胞生物学的主要领域将被检查。 第一个涉及 细胞的分离、纯化和功能鉴定 从我们的肿瘤模型中获得。 这些细胞将在 生物化学特征如混合功能氧化酶的分离状态 活性，脂质降解活性（磷脂酶），化学 其分泌颗粒的组成和鉴定的一些 调节这些分泌物的合成和释放的因子。 第二种方法将试图为以下方面创造最佳条件： 在培养液中维持分离的Clara细胞。 然后建立共培养 Clara细胞与新鲜分离的大鼠肺2型细胞，A549人 肺细胞系，必要时，病毒转化的大鼠肺2型细胞 为了重现我们在实验中观察到的2型细胞效应， vivo. 小鼠肺Clara细胞腺瘤模型的应用， 一种独特的方法来测试所提出的假设。