CELL JUNCTIONS AND CELL MEMBRANES IN THE LENS

我们建议将细胞连接和细胞膜的研究扩展到 脊椎动物的眼透镜。为了将无血管透镜保持在 缝隙连接是一种正常且透明的状态，被认为发挥着重要作用。 在调节离子和代谢之间的通信中起着至关重要的作用， 上皮细胞、纤维细胞之间以及上皮细胞和纤维之间 透镜中的细胞。最近的进展表明，透镜缝隙连接 由多种连接蛋白和结构类型组成。的意义 透镜中存在多种缝隙连接蛋白和结构 还有待确定。我们计划更详细地调查 有争议的透镜的独特结构特征和功能 缝隙连接此外，粘附连接沿着与它们的细胞 粘附分子（钙粘蛋白）和肌动蛋白束被认为是起作用的， 在控制透镜发展中的重要作用。我们计划研究 钙粘蛋白在出生前后透镜中的差异表达 发展此外，我们将扩大我们的研究目标， 深入了解细胞膜参与受体介导 光细胞增多症这种新发现的机制可能与螯合有关 并输送正常透镜所需的重要小分子 增长最后，我们将研究分子马达，驱动蛋白， 与微管为基础的细胞器运输机制所需的协会 用于形成透明透镜。 我们将在这些项目中采用几种新的方法和手段。 其中包括扫描隧道显微镜，快速冷冻，冷冻- 替代，深冷冻蚀刻电子显微镜，冷冻切片 免疫荧光标记，共聚焦激光扫描显微镜， 免疫细胞化学用冷冻替代制备物，薄切片 使用我们开发的改进的固定剂进行电子显微镜检查 实验室、示踪剂和细胞化学技术、器官培养、凝胶 电泳和免疫印迹。 本申请的长期目标是获得更好的 了解细胞连接的结构和功能作用， 透镜中的细胞膜。

We propose to extend the studies of cell junctions and cell membranes in the ocular lens of vertebrates. In order to maintain an avascular lens in a normal and transparent state, gap junctions are believed to play a crucial role in regulating ionic and metabolic communications between epithelial cells, between fiber cells, and between epithelial and fiber cells in the lens. Recent progress suggests that lens gap junctions consist of multiple connexins and structural types. The significance of the existence of multiple gap junction proteins and structures in the lens remains to be determined. We plan to investigate in greater detail the unique structural characteristics and functions of the controversial lens gap junctions. In addition, adherens junctions along with their cell adhesion molecules (cadherins) and actin bundles are thought to play an important role in governing lens development. We plan to study the differential expressions of cadherins during prenatal and postnatal lens development. Moreover, we will extend our research goals to gain some insights into the roles of cell membranes involved in receptor-mediated potocytosis. This newly-found mechanism may be involved in sequestering and transporting important small molecules necessary for normal lens growth. Finally, we will study the molecular motor, kinesin, and its association with microtubule-based organelle transport mechanisms required for the formation of a transparent lens. We will apply several new approaches and methodologies for these projects. These include scanning tunneling microscopy, rapid-freezing, freeze- substitution, deep freeze-etch electron microscopy, frozen-section immunofluorescence labeling, confocal laser scanning microscopy, immunocytochemistry using freeze-substitution preparations, thin-section electron microscopy using an improved fixative developed in our laboratory, tracer and cytochemical techniques, organ cultures, gel electrophoresis, and immunoblotting. The long-term objectives of this application are to gain a better understanding of the structure and functional role of cell junctions and cell membranes in the lens.