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.

神经元细胞生物学中的一个基本问题是膜蛋白如何在细胞体中生物合成后，将长距到轴突。轴突靶向膜蛋白对于形成和维持神经元连接至关重要以及功能性神经系统。但是，大多数膜蛋白如何递送到轴突保持不确定。神经生物学的长期视图是信号受体是组成性的通过分泌贩运运送到轴突。相反，我们发现TRKA神经营养素是神经元存活，轴突生长和炎症的基本调节剂的受体疼痛通过转胞胞病症积极地招募到轴突，这是一种基于内吞作用的机制嵌入在躯体表面中的受体被内在化和前果运输到轴突。引人注目的是，配体触发了顺行TRKA TRKA跨介症，神经生长因子（NGF），作用于轴突末端，表明有积极的反馈在时间上动态扩大轴突中受体可用性的机制需要。此外，我们确定了Trka跨经细胞增多症是由 PTP1B，一种在细胞体中的ER居民蛋白酪氨酸磷酸酶。总体目标该应用是为了阐明A的信号传导和运输机制配体触发受体靶向轴突的表征不佳。在AIM 1中，我们将定义NGF介导的机制，该机制启动细胞体内跨胞菌病，阐明受体转胞病的贩运行程和运输动力学，以及研究体内TRKA跨经细胞增多症。在AIM 2中，我们将检验以下假设。锚定的PTP1B磷酸酶通过控制促进TRKA生物功能的增长受体的长距离转介症。我们将采用现场成像，生化和分室神经元培养物中的功能分析与体内结合分析转基因小鼠以实现这些目标。这些研究会解决一个基本但研究较少的细胞生物学问题，即如何发出信号受体针对轴突，并将提供有关专门机制的洞察力增强对空间作用外部线索的神经元反应。