Cell biological mechanisms of gastrointestinal tract formation

胃肠道形成的细胞生物学机制

• 批准号: 8521274
• 负责人: Stephanie Woo
• 金额: $ 8.86万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-09-15 至 2016-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8521274
• 关键词: Actins; Address; Affect; Animal Model; Area; Behavior; Biological; Biological Models; Biological Process; Cell Communication; Cell Surface Receptors; Cell Transplantation; Cells; Congenital Abnormality; Cues; Cytoskeleton; Defect; Development; Digestive System Disorders; Disease; Ectoderm; Embryo; Embryonic Development; Endoderm; Endoderm Cell; Ensure; EphA7 Receptor; Epithelial; Future; Gastrointestinal tract structure; Genetic Techniques; Germ Layers; Goals; Homeostasis; Homologous Gene; Human; Image; Immigration; Individual; Inflammation; Knowledge; LAR tyrosine phosphatase receptor; Label; Life; Ligands; Light; Malignant Neoplasms; Mediating; Mentors; Mesoderm; Mesoderm Cell; Methods; Microarray Analysis; Molecular Genetics; Monitor; Monomeric GTP-Binding Proteins; Morbidity - disease rate; Morphogenesis; Movement; Neoplasm Metastasis; Nodal; Organ; Other Genetics; Pattern; Play; Positioning Attribute; Process; Reporting; Research; Resolution; Role; Signal Transduction; Signaling Protein; Site; Specific qualifier value; Specificity; Staging; Surface; System; Techniques; Time; Training; Transcription factor genes; Transforming Growth Factor beta; Transgenic Organisms; Tube; Zebrafish; base; cell behavior; cell motility; fluorescence imaging; gain of function; gastrointestinal; gastrointestinal system; gastrulation; gene function; genetic regulatory protein; glucose metabolism; immune function; in vivo; insulin signaling; loss of function; malformation; migration; mortality; novel; polymerization; protein function; receptor; research study; tissue repair; transcription factor; tumor

DESCRIPTION (provided by applicant): The goal of this study is to identify the mechanisms regulating early endodermal cell migration and understand how cell movements contribute to the overall formation of the gastrointestinal tract. Although much progress has been made in identifying the transcription factors that specify endodermal cells, much less is known about the cell biological processes that occur subsequently, including the onset of cell motility. Shortly after specification, endodermal cells internalize to form the inner layer of the body during a process known as gastrulation. Using the zebrafish embryo as a model system, I will examine two aspects of endodermal cell migration - random directionality and contact-dependent repulsion. For these studies, I will use high-resolution fluorescence imaging of live embryos and a novel transgenic line that I developed that fluorescently labels the actin cytoskeleton. Preliminary evidence suggests that Nodal, a signaling protein already known to induce endodermal fate, can promote endodermal migration in a directionally random manner. I will characterize the effects of Nodal signaling on the actin cytoskeleton within endodermal cells, and I will identify the actin regulatory proteins that function to promote Nodal-induced motility. In the second specific aim, I will examine the mechanisms regulating contact-dependent repulsion. This is a process whereby migrating endodermal cells are repelled away from each other after making brief contact. Using both candidate and microarray- based approaches, I will attempt to identify the cell surface receptors that initiate contact repulsion as well as the cytoplasmic signaling proteins that act downstream of these receptors. Together, directionally random motility and contact repulsion appear to drive the dispersal of endodermal cells across the surface of the early embryo, after which these cells coalesce into a single gut tube. To understand the significance of this initial dispersal, I will use gain and loss of function techniques to interfere with normal endodermal migratory behavior and assess the effects on subsequent development of the gastrointestinal tract. In the course of this study, I will gain further expertise in vertebrate gut development, whole-embryo time-lapse imaging, and quantitative methods for examining in vivo cell migration. My primary mentor, Dr. Didier Stainier, and my co-mentor, Dr. Orion Weiner, will provide additional training in these areas to help me achieve my research goals. This study will shed light on a poorly appreciated aspect of gastrointestinal development and will form the basis for a future R-level application as I continue to explore the relationship between cell migration and organ development.

描述（由申请人提供）：本研究的目的是确定调节早期内胚层细胞迁移的机制，并了解细胞运动如何促进胃肠道的整体形成。尽管在鉴定内胚层细胞特异转录因子方面已经取得了很大进展，但对随后发生的细胞生物学过程（包括细胞运动的开始）知之甚少。规格化后不久，内胚层细胞在原肠胚形成过程中内化形成身体的内层。使用斑马鱼胚胎作为模型系统，我将研究内胚层细胞迁移的两个方面 - 随机方向性和接触依赖性排斥。在这些研究中，我将使用活胚胎的高分辨率荧光成像和我开发的一种新型转基因系，该系可以荧光标记肌动蛋白细胞骨架。初步证据表明，Nodal 是一种已知可诱导内胚层命运的信号蛋白，可以以定向随机方式促进内胚层迁移。我将描述 Nodal 信号对内胚层细胞内肌动蛋白细胞骨架的影响，并且我将鉴定出促进 Nodal 诱导运动的肌动蛋白调节蛋白。在第二个具体目标中，我将研究调节接触依赖性排斥力的机制。这是一个迁移的内胚层细胞在短暂接触后相互排斥的过程。使用候选方法和基于微阵列的方法，我将尝试识别启动接触排斥的细胞表面受体以及在这些受体下游起作用的细胞质信号蛋白。定向随机运动和接触排斥似乎共同驱动了内胚层细胞在早期胚胎表面的分散，之后这些细胞合并成单个肠管。为了理解这种最初扩散的重要性，我将使用功能获得和丧失技术来干扰正常的内胚层迁移行为，并评估对胃肠道后续发育的影响。 在这项研究过程中，我将获得脊椎动物肠道发育、全胚胎延时成像以及检查体内细胞迁移的定量方法方面的进一步专业知识。我的主要导师 Didier Stainier 博士和我的共同导师 Orion Weiner 博士将在这些领域提供额外的培训，以帮助我实现我的研究目标。这项研究将揭示胃肠道发育中一个鲜为人知的方面，并将为未来 R 水平应用奠定基础，因为我将继续探索细胞迁移和器官发育之间的关系。