LAMININ AND FIBRONECTIN IN PERIPHERAL NERVE DEVELOPMENT

拟议研究的长期目标是了解 细胞外基质(ECM)蛋白纤维连接蛋白(FN)的作用 和外周神经系统(PNS)中的层粘连蛋白(LAM) 发展。细胞外基质分子调节细胞的形状、分化、 以及胚胎发育过程中的运动。在PNS中，ECM分子 似乎与神经脊迁移有关，而且在 神经肌肉接头的发育和再生。 从神经管或神经管移行的神经纤维生长锥 外周神经节穿过底物通路也有可能 以包含粘性分子。粘附性糖蛋白Fn 和林以及调解特定阶段的优秀候选人 三叉神经节细胞的迁移和分化，由于它们在 胚胎及其与三叉神经节细胞的体外相互作用。首先，什么是 FN和LAM的细胞结合域与 神经元与分子的相互作用？FN的两个域 细胞类型特异性中的神经元-底物相互作用 举止。LAM的功能区定义不那么明确，但 似乎也调节细胞类型的特定行为。离体 研究将探讨1)黏附在细胞相互作用中的作用 特定区域，2)活细胞与其相互作用时的行为 每个区域，以及3)这些相互作用的细胞骨架相关。 各种抑制试验的关键工具将是蛋白水解物FN 和LAM片段Z01MH02395和结构域特异性试剂 选择性地干扰细胞-底物的相互作用。第二, FN和LAM(以及每个区域的特定区域)如何被细胞使用 在发展中的PNS中？方法将是1)免疫化学 在光学和电子显微镜水平上，揭示时间 神经纤维和细胞外基质分子之间的空间联系， 2)体外分析神经元与复杂基质的相互作用， (3)体内神经元-细胞外基质相互作用的扰动。第三, FN和LAM的定义区域如何促进迁移 以及神经脊细胞的分化？波峰细胞相互作用 在体外与FN和LAM结合，并与这两个分子接触 活着。组织培养研究将解决1)CREST的机制 细胞迁移与2)波峰亚群分化 对这些分子的反应。以我们在细胞-ECM领域的背景 互动和我们现在可用的工具，我们将能够 准确评估FN和LAM在PNS发展中的作用。

The long-range goal of the proposed research is to understand the roles of the extracellular matrix (ECM) proteins fibronectin (FN) and laminin (LAM) in peripheral nervous system (PNS) development. ECM molecules regulate cell shape, differentiation, and movement during embryogenesis. In the PNS, ECM molecules appear to be involved in neural crest migration and in development and regeneration of neuromuscular junctions. Growth cones of nerve fibers migrating from the neural tube or peripheral ganglia traverse substrate pathways that are also likely to contain adhesive molecules. The adhesive glycoproteins FN and LAM and good candidates for mediating particular stages of PNS cell migration and differentiation, due to their locations in embryos and interactions with PNS cells in vitro. First, what is the relevance of the cell binding domains of FN and LAM to neuronal interaction with the molecules? Two domains of FN mediate neuron-substratum interaction in a cell type-specific manner. Functional regions of LAM are less well-defined, but also appear to mediate cell type-specific behavior. In vitro studies will probe 1) roles of adhesion in cell interaction with specific domains, 2) behavior of living cells as they interact with each domain, and 3) cytoskeletal correlates of these interactions. Key tools in a variety of inhibition assays will be proteolytic FN and LAM fragZ01MH02395 and domain specific reagents that selectively interfere with cell-substratum interactions. Second, how are FN and LAM (and specific regions of each) used by cells in the developing PNS? Approaches will be 1) immunochemistry at the light and electron microscopic levels, to reveal temporal and spatial associations between nerve fibers and ECM molecules, 2) analysis of neuronal interaction with complex matrices in vitro, and 3) perturbation of neuron-ECM interactions in vivo. Third, how do defined regions of FN and LAM contribute to migration and differentiation of neural crest cells? Crest cells interact with FN and LAM in vitro and are exposed to both molecules in vivo. Tissue culture studies will address 1) mechanisms of crest cell migration and 2) differentiation of crest subpopulations in response to these molecules. With our background in cell-ECM interactions and the tools now available to us, we will be able to evaluate precisely the roles of FN and LAM in PNS development.