Planar cell polarity control of axon guidance

轴突引导的平面细胞极性控制

• 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
• 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

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.

项目摘要 背侧轴突中线交叉是脊椎动物和无脊椎动物神经的重要特征 系统，对于感觉和运动系统，运动和姿势的左右协调所必需的系统。在 脊椎脊髓，背侧轴突向延伸到中线底板，然后转弯 纵向朝大脑上升。虽然生长锥的航行到地板上和横跨地板的航行 深入研究，其最终决定（无论是从中线出现之后升上还是下降）较少 理解。遗传研究清楚地暗示了平面细胞极性（PCP）途径，但 我们对PCP信号如何指导生长锥的理解是不完整的。 PCP途径是一个细胞电池 接触介导的信号通路，该信号通路在细胞之间传递极性信息以定向其定向 迁移。然而，我们对PCP信号在合理轴突指导中的作用的机械理解是 在很大程度上通过对孤立生长锥体外研究的研究。那是我们理解的主要差距 合并轴突指导是细胞接触介导的线索在纵向指导中的作用。使用 透明的斑马鱼胚胎可视化单个识别先锋的轴突和生长锥 PCP突变体中的中间神经元，我们发现需要PCP信号通路的核心成分 同样在合并神经元内及其环境中，以进行正确的轴突靶向。 PCP蛋白质本地化 到生长锥和细胞的轨迹上。我们假设生长锥将PCP信号传导到 在其直接神经上皮环境中对平面偏振线索的响应，其增长是在极化的。在目标1中 我们将通过在空间和时间上定位对PCP核心组件的要求来检验此假设 生长锥环境，以及通过生长锥膜和肌动蛋白动力学的定量实时成像 正在做出其前定位决定。在AIM 2中，我们将扩大范围以发现连续性轴突 通过目标G0 CRISPR在其他地方的PCP信号中暗示的蛋白质的指导作用 屏幕。最后，在AIM 3中，我们将再次扩展范围，以测试PCP信号功能的假设 在脊髓的纵向轴突指导中广泛。这项工作的成功结果将是一个深刻的 机械理解对背部合并神经生长锥如何两极化以偏转前期生长 平面细胞极性途径的体内，使其能够构建控制运动和 位置。