Endoplasmic Reticulum Stress in Neurodegeneration

神经变性中的内质网应激

基本信息

批准号：
10202179
负责人：
JONATHAN LIN
金额：
--
依托单位：
VETERANS ADMIN PALO ALTO HEALTH CARE SYS
依托单位国家：
美国
项目类别：
财政年份：
2017
资助国家：
美国
起止时间：
2017-02-01 至 2022-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10202179
关键词：
Affect Age Aging Alzheimer&apos s Disease American Amino Acid Substitution Amino Acids Animal Model Animals Biochemical Biological Assay Brain Cell Death Cell Survival Cell physiology Cells Data Development Disease Disease model Elderly Endoplasmic Reticulum Eukaryotic Initiation Factors Event Fibroblasts Functional disorder Genes Genetic Genetic Enhancement Haplotypes Human Impairment Integral Membrane Protein Kinetics Korean War Late Onset Alzheimer Disease Measures Messenger RNA Mission Modeling Molecular Molecular Genetics Morbidity - disease rate Mus Nerve Degeneration Nervous system structure Neurodegenerative Disorders Neurofibrillary Tangles Neurons Oral PERK kinase Pathogenesis Pathologic Pathology Patient Care Patients Pharmaceutical Preparations Pharmacology Phosphorylation Phosphotransferases Pluripotent Stem Cells Population Predisposition Progressive Supranuclear Palsy Property Protein Kinase Proteins Recombinants Research Ribosomes Risk Role Signal Transduction Signal Transduction Pathway Skin Tauopathies Testing Transgenic Mice Translations Variant Veterans Vietnam Conflict base behavioral study dimer effective therapy endoplasmic reticulum stress experimental study genetic risk factor genetic variant genome wide association study genome-wide analysis high risk histological studies human disease in vitro activity in vivo insight misfolded protein molecular pathology mortality mouse model mutant neuron loss neuronal survival neuropathology novel novel therapeutics preservation prevent protein folding protein misfolding reconstitution response risk variant small molecule stem cells tau Proteins

项目摘要

Neurodegenerative diseases are a significant cause of morbidity and mortality in elderly Veterans. No cures exist for neurodegenerative diseases, because the cellular, molecular, and genetic mechanisms that cause neurons to die with age are poorly understood. Our long-term objective is to decipher the mechanisms required for neuronal function and survival and to identify how dysfunction of these mechanisms contribute to progressive age-associated neurodegenerative diseases. Comprehensive genome wide studies of patients with late-onset Alzheimer's disease and Progressive Supranuclear Palsy recently identified the eukaryotic translation initiation factor 2α kinase 3/PKR-like endoplasmic reticulum kinase (EIF2AK3/PERK) gene as a genetic risk factor for neurodegeneration. EIF2AK3/PERK encodes an endoplasmic reticulum transmembrane protein kinase that is essential for cells to survive pathologic and environmental conditions that cause misfolded proteins and endoplasmic reticulum stress. In response to misfolded proteins and ER stress, EIF2AK3/PERK dimerizes to activate its kinase domain. Multiple EIF2AK3/PERK haplotypes with various amino acid substitutions are found in the human population. The function of EIF2AK3/PERK in neurons and the mechanism by which some EIF2AK3/PERK haplotypes cause neurodegeneration are unknown. We recently discovered that EIF2AK3/PERK haplotypes associated with neurodegeneration have significantly reduced kinase activity compared to protective haplotypes. We also found that neurons generated from skin fibroblasts of patients with high-risk EIF2AK3/PERK haplotypes showed impaired EIF2AK3/PERK signaling in response to ER stress. Last, we found that EIF2AK3/PERK signaling is robustly activated in a mouse model of tauopathy neurodegeneration. Based on these preliminary findings, our central hypothesis is that EIF2AK3/PERK is activated during neurodegeneration to preserve neuronal cell function and viability, and loss of EIF2AK3/PERK function leads to increased protein misfolding and increased ER stress that ultimately cause neuronal cell death and neurodegeneration. We propose cellular, molecular, and genetic experiments to test this hypothesis and determine the function of EIF2AK3/PERK in neurodegeneration. First, we will characterize the biochemical and enzymatic activities of high-risk and low-risk human EIF2AK3/PERK associated with neurodegeneration. We will perform biochemical studies of recombinant EIF2AK3/PERK proteins to analyze the functional consequences of amino acid alterations associated with human haplotype variants. Second, we will test if modulation of EIF2AK3/PERK signaling prevents disease in the PS19 transgenic mouse model of neurodegeneration. We will cross PS19 mice with genetically modified mice that increase EIF2AK3/PERK signaling. We will treat PS19 mice with orally available drugs that increase or inhibit EIF2AK3/PERK signaling. We will perform molecular, histologic, and behavioral studies to examine how EIF2AK3/PERK modulation affects neuropathology and neurodegeneration in this animal model. Last, we will evaluate EIF2AK3/PERK signal transduction in stem cell-derived neurons generated from patients with high-risk and low-risk EIF2AK3/PERK haplotypes. We will determine how genetic variants of EIF2AK3/PERK affect neuronal tau protein folding and neuronal susceptibility to ER stress-induced cell death. In parallel, we will test novel pharmacologic modulators of EIF2AK3/PERK signaling to see if we can prevent neuronal cell death when PERK is artificially activated. In summary, EIF2AK3/PERK variants are important genetic risk factors for developing neurodegeneration but their function and mechanisms are unknown and treatments are lacking. These studies are significant because they will reveal the role of EIF2AK3/PERK in neurons and why EIF2AK3/PERK variants in people can increase risk for developing neurodegeneration. Our studies will positively benefit the mission of the VA by identifying potential treatments to prevent neurodegeneration in Veterans and patients carrying the high-risk alleles.

神经退行性疾病是老兵发病率和死亡率的重要原因。没有治疗存在于神经退行性疾病，因为引起的细胞，分子和遗传机制随着年龄的增长而死的神经元知之甚少。我们的长期目标是破译机制神经元功能和生存所必需的，并确定这些机制的功能障碍如何有助于进行性年龄相关的神经退行性疾病。全面的患者基因组研究最近发病的阿尔茨海默氏病和渐进性超透明麻痹最近确定了真核生物翻译起始因子2α激酶3/PKR样性内质网激酶（EIF2AK3/PERK）基因作为一种神经退行性的遗传危险因素。 EIF2AK3/PERK编码内质网跨膜蛋白激酶对于细胞生存的病理和环境条件至关重要错误折叠的蛋白质和内质网应激。响应错误折叠的蛋白质和ER应激， EIF2AK3/PERK二聚体激活其激酶结构域。多个EIF2AK3/PERK单倍型在人口中发现氨基酸取代。 EIF2AK3/PERK在神经元中的功能和某些EIF2AK3/PERK单倍型引起神经退行性的机制尚不清楚。我们最近发现，与神经变性相关的EIF2AK3/PERK单倍型具有显着与保护性单倍型相比，激酶活性降低。我们还发现皮肤产生的神经元 EIF2AK3/PERK单倍型患者的成纤维细胞显示出EIF2AK3/PERK信号的受损对ER应力的反应。最后，我们发现eif2ak3/perk信号在鼠标模型中强烈激活陶氏神经变性。基于这些初步发现，我们的中心假设是 eIF2AK3/PERK在神经变性过程中被激活，以保留神经元细胞功能和生存能力，损失 EIF2AK3/PERK功能的蛋白质折叠率增加和ER应力增加，最终导致神经元细胞死亡和神经变性。我们提出了细胞，分子和遗传实验来测试该假设并确定EIF2AK3/PERK在神经变性中的功能。首先，我们将描述与之相关的高风险和低风险人EIF2AK3/PERK的生化和酶促活性神经变性。我们将对重组EIF2AK3/PERK蛋白进行生化研究以分析与人单倍型变体相关的氨基酸改变的功能后果。第二，我们将测试EIF2AK3/PERK信号的调节是否可以防止PS19转基因小鼠模型中的疾病神经变性。我们将用一般修饰的小鼠穿越PS19小鼠，以增加EIF2AK3/PERK 信号。我们将使用增加或抑制EIF2AK3/PERK信号传导的口服药物治疗PS19小鼠。我们将进行分子，组织学和行为研究，以检查EIF2AK3/PERK调制在这种动物模型中影响神经病理学和神经退行性。最后，我们将评估EIF2AK3/PERK 从具有高危和低风险患者产生的干细胞衍生神经元中的信号翻译 EIF2AK3/PERK单倍型。我们将确定EIF2AK3/PERK的遗传变异如何影响神经元TAU 蛋白质折叠和神经元对ER应激诱导的细胞死亡的敏感性。同时，我们将测试小说 EIF2AK3/PERK信号的药理调节剂，以查看我们是否可以预防神经元细胞死亡 PERK被人为地激活。总而言之，EIF2AK3/PERK变体是重要的遗传风险因素发展神经变性，但其功能和机制尚不清楚，并且缺乏治疗方法。这些研究很重要，因为它们将揭示EIF2AK3/PERK在神经元中的作用以及为什么 EIF2AK3/PERK变体的人可以增加发展神经变性的风险。我们的研究将通过确定潜在的治疗方法来防止神经退行性的疗法，从而使VA的任务受益匪浅退伍军人和携带高风险等位基因的患者。