Planar cell polarity control of axon guidance

轴突引导的平面细胞极性控制

基本信息

批准号：
10737486
负责人：
Cecilia B Moens
金额：
$ 61.62万
依托单位：
FRED HUTCHINSON CANCER CENTER
依托单位国家：
美国
项目类别：
财政年份：
2023
资助国家：
美国
起止时间：
2023-08-01 至 2027-07-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10737486
关键词：
3-Dimensional Actins Animals Anterior Axon Behavior Brain CRISPR screen Cell Transplantation Cell surface Cells Complex Cues Cytoskeleton Decision Making Dorsal Embryo Environment Epithelium Fascicle Floor Genes Genetic Genetic Markers Genetic study Goals Growth Growth Cones Image In Vitro Individual Interneurons Invertebrates Ipsilateral Learning Left Locomotion Mediating Membrane Molecular Motor Nervous System Neuroepithelial Neurons Outcome Pathway interactions Play Posture Process Proteins Reagent Resolution Role Sensory Signal Pathway Signal Transduction Specific qualifier value Spinal Spinal Cord Structure System Testing Time Vertebral column Visualization Visualization software Work Zebrafish axon growth axon guidance cell motility gene function in vivo in vivo Model migration molecular asymmetry mutant neural circuit neurodevelopment neuron development neuronal growth optogenetics planar cell polarity receptor response transmission process

项目摘要

PROJECT SUMMARY Midline crossing by dorsal commissural axons is a prominent feature of vertebrate and invertebrate nervous systems, necessary for the left-right coordination of sensory and motor systems, locomotion, and posture. In the vertebrate spinal cord, dorsal commissural axons extend towards and cross the midline floorplate, and then turn longitudinally to ascend towards the brain. While the growth cone’s voyage to and across the floorplate has been intensively studied, its final decision—whether to ascend or descend after emerging from the midline—is less well understood. Genetic studies clearly implicate the Planar Cell Polarity (PCP) pathway in this decision, but our understanding of how PCP signaling guides the growth cone is incomplete. The PCP pathway is a cell-cell contact-mediated signaling pathway that transmits polarity information between cells to orient them for directed migration. Yet our mechanistic understanding of the role of PCP signaling in commissural axon guidance is largely informed by studies of isolated growth cones in vitro. Thus, A major gap in our understanding of commissural axon guidance is the role that cell contact-mediated cues play in longitudinal guidance. Using the transparent zebrafish embryo to visualize the axons and growth cones of single identified pioneer commissural interneurons in PCP mutants, we have found that core components of the PCP signaling pathway are required equally within the commissural neuron and in its environment for correct axon targeting. PCP proteins localize to the growth cone and to the cells on its trajectory. We hypothesize that the growth cone uses PCP signaling to polarize its growth in response to planar-polarized cues in its immediate neuroepithelial environment. In Aim 1 we will test this hypothesis by locating, in space and time, the requirement for PCP core components in the growth cone environment, and by quantitative live imaging of growth cone membrane and actin dynamics as it is making its anterior targeting decision. In Aim 2 we will expand our scope to discover the commissural axon guidance role of proteins that have been implicated in PCP signaling elsewhere through a targeted G0 CRISPR screen. Finally, in Aim 3 we will expand our scope once again to test the hypothesis that PCP signaling functions broadly in longitudinal axon guidance in the spinal cord. The successful outcome of this work will be a deep mechanistic understanding of how the dorsal commissural neuron growth cone is polarized for anterior growth in vivo by the Planar Cell Polarity pathway, to enable it to build sensory circuits controlling locomotion and posture.

项目概要背连合轴突穿过中线是脊椎动物和无脊椎动物神经的一个显着特征系统，对于感觉和运动系统、运动和姿势的左右协调是必需的。脊椎动物脊髓，背连合轴突向中线底板延伸并穿过中线底板，然后转动纵向上升到大脑的同时，生长锥的航程已经到达并穿过地板。经过深入研究，它的最终决定——从中线出来后是上升还是下降——较少遗传学研究清楚地表明平面细胞极性（PCP）途径与这一决定有关，但是我们对 PCP 信号传导如何引导生长锥的理解并不完整。 PCP 通路是一个细胞-细胞通路。接触介导的信号通路，在细胞之间传递极性信息以定向它们然而，我们对 PCP 信号在连合轴突引导中的作用的机制理解是很大程度上是通过体外分离的生长锥的研究获得的，因此，我们对生长锥的理解存在重大差距。连合轴突引导是细胞接触介导的线索在纵向引导中发挥的作用。透明斑马鱼胚胎可视化单个确定的先锋连合的轴突和生长锥 PCP突变体中的中间神经元，我们发现PCP信号通路的核心成分是必需的在连合神经元及其环境中，PCP 蛋白能够正确定位。我们发现生长锥使用 PCP 信号传导来在目标 1 中，根据其直接神经上皮环境中的平面极化信号来极化其生长。我们将通过在空间和时间上定位 PCP 核心组件的需求来检验这一假设。生长锥环境，并通过生长锥膜和肌动蛋白动力学的定量实时成像正在做出其前部目标决定在目标 2 中，我们将扩大范围以发现连合轴突。通过靶向 G0 CRISPR 参与其他地方的 PCP 信号传导的蛋白质的指导作用最后，在目标 3 中，我们将再次扩大范围来测试 PCP 信号传导功能的假设。这项工作的成功成果将是一个深入的脊髓纵向轴突引导。对背连合神经元生长锥如何极化以促进前部生长的机制理解在体内通过平面细胞极性途径，使其能够建立控制运动和运动的感觉电路姿势。