Mechanisms of Prion Spread and Neuronal Toxicity

朊病毒传播和神经元毒性的机制

基本信息

批准号：
10587437
负责人：
Christina Sigurdson
金额：
$ 62.43万
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：
2023
资助国家：
美国
起止时间：
2023-02-01 至 2027-01-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10587437
关键词：
AMPA Receptors Acceleration Affect Alzheimer&apos s Disease Animal Model Automobile Driving Binding Binding Proteins Biochemical Biological Models Brain Cell Membrane Proteins Chronic Complex Creutzfeldt-Jakob Syndrome Critical Pathways Data Disease Disease Progression Dissection Electron Microscopy Electrophysiology (science)Endosomes Event Excision Functional disorder Funding Genes Glutamate Receptor Glutamates Goals Hippocampus Homeostasis Human Impairment In Vitro Infection Light Link Location Longitudinal Studies Mass Spectrum Analysis Membrane Membrane Proteins Modeling Multivesicular Body Mus Mutate Myoclonus N-Methyl-D-Aspartate Receptors Nerve Degeneration Neurodegenerative Disorders Neurons Outcome Pathologic Pathway interactions Patients Phosphorylation Phosphotransferases Physiological Postsynaptic Membrane PrP PrPSc Proteins Prion Diseases Prions Proteins Proteomics Reactive Oxygen Species Receptor Signaling Reporting Reproducibility STEM research Sampling Scaffolding Protein Signal Pathway Signal Transduction Sorting Spinal Cord Structure Synapses Synaptic Receptors Synaptic plasticity Synaptosomes Testing Time Transgenic Mice Ubiquitin Ubiquitination Up-Regulation abeta oligomer calmodulin-dependent protein kinase II conformer excitatory neuron excitotoxicity experimental study extracellular genetic manipulation in vivo insight microvesicles neuron loss neurotoxic neurotoxicity neurotransmission new therapeutic target phosphoproteomics postsynaptic presynaptic protein aggregation protein complex protein expression protein transport proteostasis receptor response synaptic function trafficking transcription factor

项目摘要

Synaptic dysfunction and neuritic dystrophy are prominent pathologic features of the prion- and Alzheimer’s disease-affected brain. Ubiquitinated protein inclusions are also commonly observed, providing strong evidence of impaired proteostatic pathways. Ubiquitination of cell membrane proteins and clearance through the ESCRT pathway (endosomal sorting complex required for transport) is critical to maintaining synaptic homeostasis. Here we will deeply investigate the ESCRT pathway contributions to disrupted synaptic homeostasis in prion disease. In prion-infected mice, we have found markedly reduced ESCRT-0 (an Hrs and STAM1 protein complex) and an enrichment of ubiquitinated proteins in synaptosomes. Strikingly, depleting neuronal Hrs in prion-infected mice shortened survival time and accelerated the degeneration of synapses, biochemically and structurally. Additionally, in a longitudinal study of the prion-infected hippocampus, we found an upregulation in the synaptic activity response gene, Arc/Arg3.1, and a chronic elevation in phosphorylated CaMKII and phosphorylated AMPA receptors, suggestive of enhanced and altered synapse function beginning in early disease. Our long-term goal is to decipher how prion and amyloid-β oligomers disrupt signaling pathways linked to the cellular prion protein, inducing proteostatic dysfunction and synaptic degeneration. Using electrophysiology, correlative light-electron microscopy, and proteomics on uninfected and prion-infected cultured neurons, we will first determine how Hrs expression impacts synapses, assessing activity, pre-and post-synaptic proteins, structure, and signaling. We will then test how distinct prion conformers impact the ESCRT pathway and neuronal signaling at glutamatergic synapses. Finally, we will investigate the contribution of glutamate receptor activity to prion spread and neurodegeneration. We will directly test how the findings in these genetically manipulated models compare to human prion-affected brain. These studies are the first to test how neuronal activity impacts prion dissemination, synaptic degeneration, and disease progression, and outcomes are expected to provide key insights into the deregulated synaptic signaling that drives neuron loss, thus revealing new therapeutic targets.

突触功能障碍和神经性营养不良是朊病毒和受阿尔茨海默病影响的大脑也常见。提供了细胞膜泛素化途径受损的有力证据。蛋白质和通过 ESCRT 途径的清除（内体分选复合物所需运输）对于维持突触稳态至关重要。在朊病毒感染的小鼠中，ESCRT 通路对突触稳态的影响显着减少。突触体中泛素化蛋白的富集显着减少了神经元的小时数。感染朊病毒的小鼠存活时间缩短并加速突触退化，另外，在对朊病毒感染者的纵向研究中。海马体中，我们发现突触活动反应基因 Arc/Arg3.1 上调，并且磷酸化 CaMKII 和磷酸化 AMPA 受体慢性升高，提示我们的长期目标是从疾病早期开始增强和改变突触功能。破译朊病毒和β淀粉样蛋白寡聚体如何破坏与细胞朊病毒相关的信号通路蛋白质，利用电生理学诱导蛋白质抑制功能障碍和突触变性，相关光电子显微镜以及未感染和朊病毒感染培养物的蛋白质组学对于神经元，我们将首先确定 Hrs 表达如何影响突触，评估活动、突触前和突触后蛋白质、结构和信号传导，然后我们将测试朊病毒的不同程度。构象异构体影响 ESCRT 通路和谷氨酸能突触的神经元信号传导。最后，我们将研究谷氨酸受体活性对朊病毒传播的贡献和我们将直接测试这些基因操纵模型中的发现。与人类受朊病毒影响的大脑进行比较，这些研究首次测试了神经活动的情况。影响朊病毒传播、突触变性和疾病进展，结果是预计将为驱动神经元丢失的突触信号解除管制提供重要见解，从而揭示新的治疗靶点。