A novel role for receptor tyrosine phosphatase in neuroblast migration

受体酪氨酸磷酸酶在神经母细胞迁移中的新作用

• 批准号: 8355610
• 负责人: PHILIP F COPENHAVER
• 金额: $ 19.25万
• 依托单位: OREGON HEALTH & SCIENCE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-05-01 至 2014-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8355610
• 关键词: Address; Adult; Affect; Affinity; Behavior; Biological Assay; Biological Models; Brain; Cell Culture Techniques; Cell Proliferation; Cells; Co-Immunoprecipitations; Complex; Coupling; Data; Defect; Degenerative Disorder; Development; Drosophila genus; Embryo; Enteral; Enteric Nervous System; Eph Family Receptors; Ephrin B Receptor; Ephrins; Equilibrium; Family; Fluorescence; Future; Gene Expression; Gene Mutation; Gene Proteins; Generations; Glycosylphosphatidylinositols; Goals; Growth; Human; Immigration; Injection of therapeutic agent; Injury; Insecta; Ligands; Link; Manduca; Manduca sexta; Membrane; Methods; Microcephaly; Modeling; Molecular; Mus; Muscle; Mutation; NGFR Protein; Neoplasm Metastasis; Nervous system structure; Neuronal Differentiation; Neurons; Organism; Orthologous Gene; Pathway interactions; Pattern; Play; Population; Positioning Attribute; Preparation; Process; Protein Tyrosine Phosphatase; Proteins; Protocols documentation; Publishing; RNA; Regulation; Research; Risk; Role; Signal Pathway; Signal Transduction; Staging; System; Testing; Tight Junctions; Travel; Venus; Work; adapter protein; cell motility; embryo culture; genetic analysis; in vivo; injured; knock-down; migration; muscle form; nerve stem cell; nervous system disorder; neuroblast; neurodevelopment; neurogenesis; novel; novel therapeutics; prevent; receptor; response; src-Family Kinases; tool; transcriptional coactivator p75; tyrosine receptor

DESCRIPTION (provided by applicant): Receptor tyrosine phosphatases (RPTPs) play important roles during neurogenesis, cell proliferation, and ne ronal positioning in the nervous system, but their mechanisms of action remain poorly understood. Genetic analyses have been complicated by the overlapping functions of different RPTP subtypes1, 2, while authentic ligands for many RPTPs remain unknown3. Recent studies using the model system Manduca sexta have identified a novel function for a specific RPTP that may clarify these issues. In the developing enteric nervous sy tem (ENS) of Manduca, placode-derived neuroblasts must migrate extensively before differentiating into ma- ture neurons, during which they travel on pre-formed muscle band pathways while avoiding the enteric midline. Previous work showed that the midline muscles express the sole Eph receptor tyrosine kinase in this system (MsEph), while the neuroblasts express its cognate Ephrin ligand (MsEphrin; a GPI-linked or type-A Ephrin)4. Intriguingly, "reverse" signaling via MsEphrin prevents the neuroblasts from crossing the MsEph-expressing midline cells, a response that involves the local activation of a Src family kinase (SFK) and retraction of their leading processes5, 6. In contrast, conventional "forward" signaling via MsEph receptors plays no role in this process, providing the first example of Ephrin-A reverse signaling in the control of neuroblast positioning. However, the mechanisms by which GPI-linked Ephrins transduce signals across the membrane remain poorly understood. An affinity screen for MsEphrin co-receptors identified PTP10D, a "type-III" RPTP that regulates midline axonal responses in the CNS2. Preliminary studies showed that PTP10D is co-expressed with MsEph- rin by the neuroblasts, while inhibiting PTP10D expression induced the same pattern of ectopic midline cros- sovers caused by blocking MsEphrin signaling. Intriguingly, the PDZ adapter protein ZO-1 (zonula occludens- 1) was also identified in this screen, and shown to co-localize with MsEphrin and PTP10D in the neuroblasts. Originally classified as a tight junction protein7, ZO-1 can also regulate cell migration in vitro8, 9 and may interact with RPTPs and SFKs in a variety of contexts10-12. The overall objective of this proposal is to determine how PTP10D regulates neuroblast migration in the developing ENS. The central hypothesis is that PTP10D acts as a co-receptor for MsEphrin, coupling this GPI-linked Ephrin with ZO-1 and its downstream effectors. Specific aims will test the role of PTP10D and ZO-1 in MsEphrin-dependent aspects of migration, using published methods to manipulate gene expression and protein interactions in embryo culture. These studies will provide essential new data for an R01 application, with the goal of comprehensively defining the mechanisms of Ephrin-A reverse signaling in the nervous system. Public Heath Relevance: Demonstrating novel roles for RPTPs and ZO-1 in Ephrin-A signaling will provide new tools for investigating why human mutations that affect Ephrin-As result in defective brain growth13, and for developing new therapeutic strategies that address neuro- degenerative conditions in which Ephrin-A reverse signaling may be misregulated14-16. PUBLIC HEALTH RELEVANCE: The proposed research will investigate a novel role for receptor tyrosine phosphatases (RPTPs) as co- receptors for type-A Ephrins in the control of neuroblast migration. RPTPs and Ephrin-As have been independently linked with normal brain development and neurogenic responses to traumatic injury, but their functional interactions with the adapter protein ZO1 have not previously been recognized. Defining the mechanisms by which RPTPs and ZO-1 transduce Ephrin A-dependent signals in a model system will provide a new perspective on how this signaling pathway may regulate neuronal differentiation in both the embryonic an adult nervous system, and in the context of neurological disorders in which RPTP-Ephrin interactions may be impaired.

描述（由申请人提供）：受体酪氨酸磷酸酶（RPTPS）在神经系统中在神经发生，细胞增殖和NE RONAL定位中在神经系统中起重要作用，但它们的作用机理仍然知之甚少。不同RPTP亚型1、2的重叠函数使遗传分析变得复杂，而许多RPTP的正宗配体仍然未知3。使用模型系统Manduca Sexta的最新研究确定了可能阐明这些问题的特定RPTP的新功能。在甘达的发展中肠神经系统（ENS）中，placode衍生的神经细胞必须进行广泛的迁移，然后再分为神经元，在此期间，它们以预先形成的肌肉带途径行进，同时避免肠中中线。先前的工作表明，中线肌肉在该系统（MSEPH）中表达唯一的EPH受体酪氨酸激酶，而神经细胞表达其同源源代蛋白配体（msephrin; gpi链接或gpi链接或a型ephrin）4。有趣的是，通过msephrin的“反向”信号阻止神经细胞跨越表达MSEPH的中线细胞，该响应涉及SRC家族激酶（SFK）的局部激活，并撤回其领先过程5，其前期的“远期”典型的典型典型的典范 - 6。神经细胞定位的控制。然而，跨膜跨GPI连接的埃弗林转导信号的机制仍然鲜为人知。 MSEPHRIN共受体的亲和力屏幕确定了PTP10D，这是一种“类型III” RPTP，可调节CNS2中的中线轴突响应。初步研究表明，PTP10D由神经细胞与MSEPH-rin共表达，而抑制PTP10D表达的表达诱导了由膜源信号阻断引起的异位中线CROS肥皂的相同模式。有趣的是，在此屏幕中还鉴定了PDZ衔接蛋白ZO-1（Zonula occludens-1），并显示在神经细胞中与Msephrin和ptp10d共定位。 ZO-1最初被归类为紧密连接蛋白7，还可以调节体外8、9和5月的细胞迁移 在各种上下文中与RPTP和SFK互动10-12。该提案的总体目的是确定PTP10D如何调节发育中的ENS中的神经细胞迁移。中心假设是PTP10D充当MSEPHRIN的共受体，将此与ZO-1及其下游效应子偶联在一起。具体目的将使用公开的方法来操纵胚胎培养中的基因表达和蛋白质相互作用，检验PTP10D和ZO-1在迁移msephrin依赖方面的作用。这些研究将为R01应用提供必不可少的新数据，目的是全面地定义神经系统中Ephrin-A反向信号的机制。公共荒地相关性：在ephrin-A信号中展示RPTP和ZO-1的新作用将提供新的工具，以调查为什么影响ephrin-a的人类突变会导致脑生长有缺陷13，以及开发新的治疗策略，以解决神经蛋白变性状况，而在这种情况下，ephrin-a反向信号传导的反向信号传递可能会误导14-16。 公共卫生相关性：拟议的研究将研究受体酪氨酸磷酸酶（RPTP）作为A型Ephrins的共同受体的新作用，以控制神经细胞迁移。 RPTP和Ephrin-AS已与正常的脑发育和对创伤性损伤的神经源性反应独立联系，但是它们与衔接蛋白ZO1的功能相互作用以前尚未被认识到。在模型系统中定义RPTP和ZO-1传递Ephrin A依赖性信号的机制将提供有关该信号通路如何调节成人神经系统以及RPTP-EPP-EPHRIN相互作用的神经系统疾病中的神经元分化的新观点。