Mechanisms of Prion Spread

朊病毒传播机制

基本信息

批准号：
9910452
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 2022-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9910452
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.

朊病毒病是进展最快的神经退行性疾病之一，病理学特征为细胞外朊病毒聚集、突触损伤、神经元丢失、大脑和脊髓中的严重星形胶质细胞增生通过朊病毒聚集传播。神经解剖学上连接的大脑区域，但朊病毒如何从细胞到细胞进行物理传播在体外，朊病毒聚集体在质膜、内体和内体中形成。存在于多泡体中，并从慢性感染的细胞的外泌体中释放出来。该应用的目标是确定细胞内囊泡朊病毒贩运如何促进使用体外和体内模型研究细胞间朊病毒通过中枢神经系统的传播我们之前采用了多种方法来进行结构跟踪。从轴突末端到神经细胞体的各种朊病毒，并确定了生物物理我们发现了传播到中枢神经系统的高毒力朊病毒的特性。亚纤维状和纤维状朊病毒通过巨胞饮作用被神经元内化。只有小的、亚原纤维的朊病毒从神经外部位扩散到大脑中，从而聚集。大小是朊病毒扩散到中枢神经系统的基础。我们还确定了翻译后病毒的传播。朊病毒蛋白的修饰可以改变聚集体堆积排列并导致最后，我们发现自噬清除途径是新的朊病毒株的出现。在本次更新中，我们的目标是确定如何在含有朊病毒聚集体的肌肉细胞中诱导。神经元和神经胶质细胞中朊病毒的囊泡运输影响朊病毒在中枢神经系统中的传播。具体目标 1，我们将定义控制包装成的朊病毒的物理特性在具体目标 2 中，我们将确定细胞内朊病毒转化和的关键调节因子。通过操纵囊泡转运途径来清除神经元和星形胶质细胞。将表征感染朊病毒的人类和小鼠的囊泡调节蛋白表达在特定目标 3 中，我们将确定如何对早期和晚期进行细胞特异性抑制。囊泡运输的各个阶段改变了朊病毒疾病的进展。首先探讨囊泡内朊病毒运输途径对体内朊病毒传播的贡献，并将有助于揭示囊泡运输如何影响朊病毒的转化、清除和快速随着大脑的传播，所提出的研究显得尤为重要。认识阿尔茨海默病和其他疾病中发生的内体和溶酶体功能障碍神经退行性疾病，以及治疗干预的潜在机会在蛋白质聚集体清除途径中。