In Vivo Analysis of the Mechanisms of Neural Crest Migration

描述(申请人提供)：最具破坏性的出生缺陷之一会影响神经脊，这是一种高度迁移的干细胞样群，有助于颅面部和心血管发育，以及周围和肠道神经系统组装。细胞谱系追踪和组织移植研究表明，神经脊细胞(NCC)的迁移路径以离散的隔离流形式出现，由无神经脊的排斥区隔开，似乎防止了NCC亚群的混合，并确保它们到达精确的靶点。这些发现支持神经脊细胞引导线索来自胚胎微环境和细胞交流的前提。最值得注意的是我们在体内产生的数据，表明细胞-细胞和细胞-环境的相互作用可能会影响神经脊的定向迁移。基于这些观察，我们建议检验中央假设，即与胚胎神经脊丰富区域相关的微环境和细胞-细胞相互作用包含信息线索，有可能将细胞定向到精确的靶点。我们的长期目标是了解神经脊迁移的生物学机制，这最终导致器官发育。我们的短期目标是在活体模型中确定颅骨NCC迁移流形成的关键细胞和分子机制。利用活体分子扰动和胚胎显微手术，结合光活化细胞标记、4-D共聚焦成像、细胞跟踪和细胞行为分析，我们提出：目标1：利用活体光激活细胞标记、4-D共聚焦成像、细胞跟踪和细胞行为分析来表征脑神经脊移行所必需的特定和动态的细胞相互作用。目的2：研究胚胎微环境中神经纤毛蛋白在神经脊迁移信号和调控中的作用。目的：研究胚胎微环境在神经脊迁移信号和调控中的作用，重点研究神经纤毛素-信号素和神经纤毛素-血管内皮细胞生长因子的相互作用。 公共卫生相关性：在这些研究完成后，我们希望对直接调节神经脊迁移的指导线索和路径有更多的了解，这些指导线索和路径可以转化为新的治疗应用。

DESCRIPTION (provided by applicant): One of the most devastating birth defects affect the neural crest, a highly migratory stem cell-like population that contribute to craniofacial and cardiovascular development, and peripheral and enteric nervous system assembly. Cell lineage tracing and tissue transplantation studies have revealed the neural crest cell (NCC) migratory pathways emerge as discrete segregated streams, separated by neural-crest-free exclusion zones that appear to prevent the intermixing of NCC subpopulations and ensure their arrival at precise targets. These findings support the premise that neural crest cell guidance cues derive from the embryonic microenvironment and cell communication. Most noteworthy are the data we have generated in vivo showing cell-cell and cell-environment interactions may influence the directional migration of the neural crest. Based on these observations, we propose to test the central hypothesis that the microenvironment and cell-cell interactions associated with the neural crest-rich regions of the embryo contain informational cues with the potential to direct cells to precise targets. Our long term goal is to understand the biological mechanisms underlying neural crest migration that ultimately results in organ development. Our short term goal is to identify the key cellular and molecular mechanisms underlying the sculpting of cranial NCC migratory streams within an in vivo model. Using in vivo molecular perturbations and embryo microsurgery, together with photoactivation cell labeling, 4-D confocal imaging, cell tracking and cell behavior analyses, we propose to: Aim 1: Characterize the specific and dynamic cellular interactions essential for cranial neural crest migration using in vivo photoactivation cell labeling, 4-D confocal imaging, cell tracking and cell behavior analyses. Aim 2: To determine the role of neuropilins within the embryonic microenvironment in signaling and modulating neural crest migration. Aim 3: Investigate the role of the embryonic microenvironment in signaling and modulating neural crest migration, with particular focus on neuropilin- semaphorin and neuropilin-VEGF interactions. Public Health Relevance: At the completion of these studies, we expect to have an increased understanding of guidance cues and pathways that directly modulate neural crest migration that could be translated for novel therapeutic applications.