Directed growth cone migration by calcium signals

通过钙信号定向生长锥迁移

• 批准号: 7684613
• 负责人: James Q Zheng
• 金额: $ 26.29万
• 依托单位: EMORY UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-09-15 至 2012-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7684613
• 关键词: Address; Affect; Architecture; Axon; BMP7 gene; Behavior; Binding; Biochemical; Biological; Biological Assay; Biological Models; Brain; Brain-Derived Neurotrophic Factor; Calcineurin; Calcium; Calcium Signaling; Calmodulin; Cells; Cellular Structures; Chimeric Proteins; Classification; Commit; Complex; Coupling; Cues; Development; Embryo; Embryonic Development; Environment; Equilibrium; Event; Extracellular Space; Foundations; Frequencies; Generations; Goals; Growth Cones; Image; Image Analysis; Immunity; Inflammatory Response; Injection of therapeutic agent; Instruction; Interneurons; Knowledge; Lasers; Leukocyte Chemotaxis; Life; Link; Mediating; Messenger RNA; Methods; Modeling; Molecular; Motor Neurons; Movement; Neoplasm Metastasis; Nerve; Neural tube; Neurons; PTK2 gene; Pathway interactions; Pattern; Phosphoric Monoester Hydrolases; Phosphorylation; Phosphotransferases; Physiological; Population Heterogeneity; Principal Investigator; Property; Public Health; Reagent; Recovery; Regulation; Resolution; Role; Second Messenger Systems; Semaphorin-3A; Serine; Signal Pathway; Signal Transduction; Source; Staging; Stimulus; Surface; System; Techniques; Temperature; Testing; Tissues; Translating; Tyrosine Phosphorylation; Work; Wound Healing; Xenopus; angiogenesis; axon growth; calcineurin phosphatase; cancer cell; cell motility; digital imaging; directional cell; embryo stage 2; experience; extracellular; human NTN1 protein; in vivo; insight; migration; mutant; netrin-1; neurodevelopment; novel; overexpression; photoactivation; photolysis; programs; public health relevance; receptor; research study; response; second messenger; spatiotemporal; treatment strategy

DESCRIPTION (provided by applicant): The cell's ability to sense the environment and to determine the direction and proximity of an extracellular stimulus, followed by correct movement, is fundamental not only for neural development (e.g. neuronal migration and growth cone guidance) but also for immunity, angiogenesis, wound healing, and embryogenesis. Directional cell movement is also crucial for many pathological events, especially cancer-cell metastasis. Therefore, a better understanding of the cellular mechanisms that underlie the directional responses of cells to extracellular stimuli would constitute a major advance of our basic knowledge on directional cell motility and could provide the foundation for developing strategies and treatments for many illnesses. The proposed study will use nerve growth cones as the model to study the spatiotemporal Ca2+ signaling mechanisms underlying directional motility in response to extracellular cues. Calcium is a key second messenger that regulates a variety of cell motility, including directed cell migration. It has been established that Ca2+ mediates growth cone responses to guidance cues, including attractive and repulsive turning responses. Recent studies indicate that different, localized Ca2+ signals elicit a balancing act on the activity of calcium-calmodulin- dependent kinase II (CaMKII) and Calcineurin (CaN) phosphatase to control the attractive and repulsive turning of the growth cone. This application aims to further evaluate the Ca2+ mechanisms that control bidirectional growth cone steering in response to guidance cues. Three specific aims are proposed: (1) to examine the spatiotemporal patterns of cytosolic Ca2+ signals and their role in controlling growth cone steering, (2) to investigate the downstream mechanisms that sense various Ca2+ signals to control growth cone turning, (3) to test the hypothesis that FAK/Src links Ca2+ signaling to tyrosine phosphorylation in growth cone guidance. The proposed studies will take advantage of our rigorous assays of growth cone turning and a combination of high-resolution digital imaging, photoactivation of caged compounds, and molecular manipulation of signaling components. In particular, direct manipulation of intracellular Ca2+ concentrations by focal laser-induced photolysis (FLIP) of caged Ca2+ will be extensively used for dissecting the signaling components. Together, these experiments represent a comprehensive study that aims to understand the Ca2+ signaling mechanisms underlying growth cone motility and guidance. The long-term goal is to understand the molecular and cellular mechanisms that allow axonal growth cones to navigate through complex extracellular spaces for establishing intricate connections. Results from this study will not only advance our knowledge of molecular mechanisms underlying precise neuronal wiring during brain development and recovery, but also provide important insights into the cellular mechanisms underlying directional sensing of migrating cells during important biological responses such as chemotaxis of leukocytes during inflammatory response. PUBLIC HEALTH RELEVANCE: The cell's ability to sense the environment and to determine the direction and proximity of an extracellular stimulus, followed by correct movement, is fundamental not only for neural development (e.g. neuronal migration and growth cone guidance) but also for immunity, angiogenesis, wound healing, and embryogenesis. Directional cell movement is also crucial for many pathological events, especially cancer-cell metastasis. Therefore, a better understanding of the cellular mechanisms that underlie the directional responses of cells to extracellular stimuli would constitute a major advance of our basic knowledge on directional cell motility and could provide the foundation for developing strategies and treatments for many illnesses. The proposed study will use nerve growth cones as the model to study the spatiotemporal Ca2+ signaling mechanisms underlying directional motility in response to extracellular cues. The results from this set of studies will provide significant insights into the cellular mechanisms of growth cone pathfinding, as well as of directed cell movement in many physiological and pathological events. Therefore the work is directly relevant to public health.

描述(申请人提供)：细胞感知环境的能力，确定细胞外刺激的方向和接近程度，然后正确的运动，不仅对神经发育(例如神经元迁移和生长锥引导)，而且对免疫、血管生成、伤口愈合和胚胎发生都是基本的。细胞的定向运动在许多病理事件中也是至关重要的，尤其是癌细胞转移。因此，更好地理解细胞对细胞外刺激的定向反应的细胞机制将是我们关于定向细胞运动的基础知识的重大进步，并可能为开发许多疾病的策略和治疗方法提供基础。这项拟议的研究将以神经生长锥为模型，研究细胞外提示下定向运动潜在的时空钙信号机制。钙是调节多种细胞运动的关键第二信使，包括定向细胞迁移。已经证实，钙离子介导生长锥对引导线索的反应，包括吸引和排斥的转向反应。最近的研究表明，不同的、局部的钙信号会对钙调素依赖的激酶II(CaMKII)和钙调神经磷酸酶(CaN)的活性产生平衡作用，从而控制生长锥的吸引力和排斥性的转动。这项申请旨在进一步评估钙离子机制，控制双向生长锥反应的指导线索。我们提出了三个具体的目标：(1)研究细胞内钙信号的时空模式及其在控制生长锥转向中的作用；(2)研究感应不同的钙信号来控制生长锥转向的下游机制；(3)检验FAK/Src在生长锥导向中将钙信号与酪氨酸磷酸化联系起来的假设。拟议的研究将利用我们对生长锥体转动的严格分析，以及高分辨率数字成像、笼状化合物的光激活和信号组件的分子操作的组合。特别是，通过聚焦激光诱导的钙离子光解(FliP)直接操纵细胞内的钙离子浓度将被广泛地用于剖析信号成分。总之，这些实验代表了一项全面的研究，旨在了解生长锥运动和指导下的钙信号机制。长期目标是了解分子和细胞机制，使轴突生长锥在复杂的细胞外空间中导航，建立复杂的连接。这项研究的结果不仅将促进我们对大脑发育和恢复过程中精确神经元连接的分子机制的了解，还将为在重要的生物反应中定向感知迁移细胞的细胞机制提供重要的见解，例如炎症反应中白细胞的趋化。与公共健康相关：细胞感知环境并确定细胞外刺激的方向和接近程度，然后正确移动的能力，不仅对神经发育(例如神经元迁移和生长锥引导)至关重要，而且对免疫、血管生成、伤口愈合和胚胎发育也是至关重要的。细胞的定向运动在许多病理事件中也是至关重要的，尤其是癌细胞转移。因此，更好地理解细胞对细胞外刺激的定向反应的细胞机制将是我们关于定向细胞运动的基础知识的重大进步，并可能为开发许多疾病的策略和治疗方法提供基础。这项拟议的研究将以神经生长锥为模型，研究细胞外提示下定向运动潜在的时空钙信号机制。这组研究的结果将对生长锥寻路的细胞机制以及许多生理和病理事件中的定向细胞运动提供重要的见解。因此，这项工作直接关系到公众健康。