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）蛋白纤连蛋白（FN）的作用 和层粘连蛋白（LAM）在周围神经系统（PNS） 发展 ECM分子调节细胞形状、分化， 以及胚胎发育过程中的运动。 在PNS中，ECM分子 似乎与神经嵴迁移有关， 神经肌肉接头的发育和再生。 从神经管迁移的神经纤维的生长锥或 周围神经节穿过底物通路， 来容纳粘性分子。 粘附糖蛋白FN 和林和良好的候选人调解特定阶段的 PNS细胞的迁移和分化，由于它们在 胚胎和体外与PNS细胞的相互作用。 什么是 FN和LAM的细胞结合结构域与 神经元与分子的相互作用 FN的两个结构域 介导细胞类型特异性的神经元-基质相互作用 方式 LAM的功能区域不太明确，但 也似乎介导细胞类型特异性行为。 体外 研究将探讨1）粘附在细胞相互作用中的作用 特定的领域，2）活细胞的行为，因为它们与 每个结构域，和3）这些相互作用的细胞骨架相关。 各种抑制试验中的关键工具是蛋白水解FN 和LAM片段Z 01 MH 02395以及结构域特异性试剂， 选择性地干扰细胞-基质相互作用。 第二、 细胞如何使用FN和LAM（以及各自的特定区域） 在发展中的PNS？ 方法将是1）免疫化学 在光学和电子显微镜水平上， 以及神经纤维和ECM分子之间的空间关联， 2)分析体外神经元与复杂基质的相互作用， 和3）体内神经元-ECM相互作用的扰动。 第三、 FN和LAM的特定区域如何促进迁移 和神经嵴细胞的分化 嵴细胞相互作用 与FN和LAM在体外，并暴露于这两种分子， vivo. 组织培养研究将解决1）冠的机制 细胞迁移和2）嵴亚群的分化 对这些分子的反应。 以我们在细胞外基质方面的背景 互动和工具，现在提供给我们，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.