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Mechanisms of Prion Spread

朊病毒传播机制

基本信息

批准号：
10162673
负责人：
Christina Sigurdson
金额：
$ 33.91万
依托单位：
UNIVERSITY OF CALIFORNIA, SAN DIEGO
依托单位国家：
美国
项目类别：
财政年份：
2012
资助国家：
美国
起止时间：
2012-09-15 至 2023-01-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10162673
关键词：
Affect Alzheimer&apos s Disease Amyotrophic Lateral Sclerosis Astrocytes Autophagocytosis Axonal Transport Biological Models Brain Brain region Cell membrane Cells Cessation of life Chronic Data Disease Disease Progression Distal Early Endosome Endosomes Functional disorder Funding Goals Human Impairment In Vitro Knockout Mice Lead Lymphoid Tissue Lysosomes Microglia Molecular Conformation Multivesicular Body Mus Muscle Cells Neuraxis Neurodegenerative Disorders Neuroglia Neurons Parkinson Disease Pathologic Pathway interactions Peripheral Nerves Pharmacology Play Post-Translational Protein Processing PrP PrPSc Proteins Presynaptic Terminals Prion Diseases Prion Pathway Prions Property Repression Role Route STEM research Scrapie Site Sorting - Cell Movement Spinal Cord Structure Symptoms Synapses Tauopathies Testing Therapeutic Intervention Virulent astrogliosis base biophysical properties cell type exosome experimental study extracellular genetic regulatory protein in vivo in vivo Model insight late endosome mouse model neuron loss neuronal cell body new therapeutic target physical property prion-like protein aggregation protein expression synucleinopathy trafficking transmission process uptake vesicle transport

项目摘要

Prion diseases are among the most rapidly progressive neurodegenerative disorders and are characterized pathologically by extracellular prion aggregates, synaptic damage, neuronal loss, and severe astrogliosis in the brain and spinal cord. Prion aggregates spread through neuroanatomically connected brain regions, yet how prions physically spread from cell-to-cell is poorly understood. In vitro, prion aggregates form on the plasma membrane, in endosomes, and in multivesicular bodies, and are released in exosomes from chronically infected cells. A major goal of this application is to determine how intra-cellular vesicular prion trafficking contributes to inter-cellular prion spread through the central nervous system using in vitro and in vivo model systems. We have previously employed a broad range of approaches to track structurally diverse prions from axon terminals to neuronal cell bodies and have determined the biophysical properties of highly virulent prions that spread into the CNS. We discovered that small, subfibrillar and fibrillar prions were internalized by neurons through macropinocytosis. However, only the small, subfibrillar prions spread from extraneural sites into the brain. Thus, aggregate size underlies prion spread into the CNS. We also determined that post-translational modifications in the prion protein can alter aggregate packing arrangements and lead to the emergence of new prion strains. Finally, we found that autophagic clearance pathways were induced in muscle cells harboring prion aggregates. In this renewal, we aim to determine how the vesicular trafficking of prions in neurons and glia impacts prion spread through the CNS. In Specific Aim 1, we will define the physical properties of a prion that govern packaging into exosomes. In Specific Aim 2, we will identify key regulators of intracellular prion conversion and clearance in neurons and astrocytes by manipulating vesicular transit pathways. Additionally we will characterize vesicular regulatory protein expression in prion-infected humans and in mouse models. In Specific Aim 3, we will determine how cell-specific repression of early and late stages of vesicular trafficking modifies prion disease progression. These experiments are the first to probe the contribution of intra-vesicular prion trafficking pathways to prion spread in vivo, and will help unravel how vesicular transport impacts prion conversion, clearance, and rapid spread through the brain. The proposed studies are particularly important with the growing recognition of endosomal and lysosomal dysfunction occurring in Alzheimer’s and other neurodegenerative diseases, and with potential opportunities arising for therapeutic intervention in protein aggregate clearance pathways.

Prion病是进展最快的神经退行性疾病之一，病理特征为细胞外Pron聚集，突触损伤，神经元丢失，以及大脑和脊髓中严重的星形胶质细胞增生症。普里子聚集体散布在神经解剖学上连接的大脑区域，但如何在物理上从细胞传播到细胞人们对此知之甚少。在体外，Pron聚集体形成在质膜上，在内体中，以及在多囊体中，并在慢性感染细胞的外体中释放。一位少校这项应用的目标是确定细胞内泡泡蛋白运输是如何促进用体外和体内模型研究细胞间病毒通过中枢神经系统的传播系统。我们以前采用了广泛的方法来从结构上跟踪从轴突终末到神经元胞体的不同普恩决定了生物物理传播到中枢神经系统的高毒力病毒的特性。我们发现，小的，亚纤丝和纤丝蛋白通过巨噬细胞吞噬作用被神经元内化。然而，只有细小的亚纤维蛋白从神经外部位扩散到大脑中。因此，聚合大小是普恩病毒扩散到中枢神经系统的基础。我们还确定，后翻译 Prion蛋白的修饰可以改变聚集堆积排列，并导致出现了新的病毒株。最后，我们发现自噬清除途径是在含有蛋白聚合体的肌肉细胞中被诱导。在这次更新中，我们的目标是确定如何普恩在神经元和神经胶质细胞中的囊泡运输影响普恩在中枢神经系统的传播。在……里面具体目标1，我们将定义Pron的物理性质，它支配包装成外显体。在特定的目标2中，我们将确定细胞内Pron转换的关键调节因子和通过操纵囊泡转运通路清除神经元和星形胶质细胞。此外，我们将表征在普恩病毒感染的人和小鼠体内的囊泡调节蛋白的表达模特们。在特定的目标3中，我们将确定细胞特异性抑制的早期和晚期泡囊运输的不同阶段改变了普里恩疾病的进展。这些实验是首先探讨泡内普恩病毒转运途径对体内普恩病毒传播的贡献，并将有助于揭示囊泡运输如何影响普利子的转化、清除和快速通过大脑传播。建议的研究尤其重要，因为阿尔茨海默病和其他疾病患者对内体和溶酶体功能障碍的认识神经退行性疾病，以及潜在的治疗干预机会在蛋白质聚集清除途径中。