Neurotrophic factor trafficking and signaling in development and disease

发育和疾病中的神经营养因子运输和信号传导

基本信息

批准号：
10377384
负责人：
Rejji Kuruvilla
金额：
$ 40.03万
依托单位：
JOHNS HOPKINS UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2019
资助国家：
美国
起止时间：
2019-04-01 至 2024-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10377384
关键词：
Active Biological Transport Address Adhesions Anabolism Attenuated Axon Axonal Transport Binding Biochemical Biological Biological Process Cell membrane Cells Cellular biology Communication Complement Cues Data Destinations Development Diffuse Disease Endocytosis Ensure Event Family Feedback Fluorescence Microscopy Goals Growth Growth Factor Health Image Injury Kinetics Knock-in Mouse Length Ligands Maintenance Mediating Membrane Proteins Membrane Transport Proteins Modeling Monitor Mus Natural regeneration Nerve Nerve Growth Factor Receptors Nerve Growth Factors Nervous system structure Neurobiology Neurons Neurotrophic Tyrosine Kinase Receptor Type 1 Organelles PTPN1 gene Peripheral Phosphoric Monoester Hydrolases Phosphorylation Point Mutation Presynaptic Terminals Process Protein Tyrosine Kinase Protein Tyrosine Phosphatase Proteins Receptor Cell Receptor Protein-Tyrosine Kinases Receptor Signaling Recovery of Function Recruitment Activity Role Signal Transduction Signaling Protein Sorting - Cell Movement Surface Synapses Synaptic Transmission Testing Time Tissues Tyrosine Tyrosine Phosphorylation anterograde transport axon growth base experimental study in vivo inflammatory pain insight meter millimeter nerve repair nerve supply neurodevelopment neuron development neuronal cell body neurotrophic factor prevent protein function receptor receptor internalization response retrograde transport scale up trafficking transcytosis

项目摘要

A fundamental question in neuronal cell biology is how membrane proteins are transported long-distance to axons after biosynthesis in cell bodies. Axon targeting of membrane proteins is critical for the formation and maintenance of neuronal connections and for a functional nervous system. Yet, how most membrane proteins are delivered to axons remains undefined. A long-held view in neurobiology is that signaling receptors are constitutively delivered to axons via secretory trafficking. In contrast, we found that TrkA neurotrophin receptors that are essential regulators of neuron survival, axon growth, and inflammatory pain are actively recruited to axons via transcytosis, an endocytosis-based mechanism where receptors embedded in soma surfaces are internalized and anterogradely transported to axons. Strikingly, anterograde TrkA transcytosis is triggered by the ligand, Nerve Growth Factor (NGF), acting on axon terminals, suggesting a positive feedback mechanism that serves to dynamically scale up receptor availability in axons during times of need. Furthermore, we identified that TrkA transcytosis is primed by the activity of PTP1B, an ER-resident protein tyrosine phosphatase, in cell bodies. The overall goal of this application is to elucidate the signaling and trafficking mechanisms underlying a poorly characterized mode of ligand-triggered targeting of receptors to axons. In Aim 1, we will define NGF-mediated mechanisms that initiate transcytosis in cell bodies, elucidate the trafficking itinerary and transport kinetics of receptor transcytosis, and investigate TrkA transcytosis in vivo. In Aim 2, we will test the hypothesis that ER- anchored PTP1B phosphatase promotes a gain of TrkA biological function by controlling the long-distance transcytosis of receptors. We will employ live imaging, biochemical, and functional analyses in compartmentalized neuron cultures in combination with in vivo analyses of genetically modified mice to accomplish these goals. These studies will address a fundamental, yet poorly studied, cell biological question of how signaling receptors are directed to axons, and will provide insight into specialized mechanisms that enhance neuronal responsiveness to spatially acting extrinsic cues.

神经细胞生物学的一个基本问题是膜蛋白如何在细胞体内生物合成后长距离运输至轴突。轴突靶向膜蛋白对于神经元连接的形成和维持至关重要以及功能性神经系统。然而，大多数膜蛋白是如何传递到轴突仍未定义。神经生物学中长期持有的观点是信号受体是组成型的通过分泌运输传递至轴突。相反，我们发现 TrkA 神经营养素受体是神经元存活、轴突生长和炎症的重要调节因子疼痛通过胞吞作用（一种基于内吞作用的机制）主动招募到轴突嵌入体细胞表面的受体被内化并顺行运输到轴突。引人注目的是，顺行 TrkA 转胞吞作用是由配体触发的，神经生长因子（NGF），作用于轴突末梢，表明正反馈用于动态扩大轴突中受体可用性的机制的需要。此外，我们发现 TrkA 转胞吞作用是由以下活性引发的： PTP1B 是细胞体内的一种内质网驻留蛋白酪氨酸磷酸酶。总体目标为该应用程序旨在阐明潜在的信号传导和贩运机制配体触发的受体靶向轴突的模式尚不明确。在目标 1 中，我们将定义 NGF 介导的启动细胞体转胞吞作用的机制，阐明受体转胞吞作用的运输行程和运输动力学，以及研究体内 TrkA 转胞吞作用。在目标 2 中，我们将检验以下假设：ER- 锚定 PTP1B 磷酸酶通过控制促进 TrkA 生物学功能的获得受体的长距离转胞吞作用。我们将采用实时成像、生化和区室神经元培养物与体内功能相结合的功能分析对转基因小鼠进行分析以实现这些目标。这些研究将解决一个基本但研究很少的细胞生物学问题，即信号传导如何受体针对轴突，并将提供对特殊机制的见解增强神经元对空间作用的外在线索的反应性。