Investigating the role of an EIF2B3 variant as an Alzheimer's disease risk modifier

研究 EIF2B3 变体作为阿尔茨海默病风险调节剂的作用

基本信息

批准号：
10680062
负责人：
Francesca Garretti
金额：
$ 6.91万
依托单位：
ICAHN SCHOOL OF MEDICINE AT MOUNT SINAI
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：
2023-03-23 至 2026-03-22
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10680062
关键词：
Affect Age Age Years Alleles Alzheimer&apos s Disease Alzheimer&apos s disease patient Alzheimer&apos s disease risk Amino Acid Substitution Amyloid deposition Apolipoprotein E Bacteria Biological Assay Brain CRISPR/Cas technology Cell physiology Cells Cellular Stress Cholesterol Clinical Cognitive Complex Critical Thinking Deposition Disease EIF2B2 gene Exhibits Fellowship Fluorescence Genes Genetic study Genotype Goals Guanine Guanine Nucleotide Exchange Factors Hematopoietic stem cells High Pressure Liquid Chromatography Homeostasis Human Human Genetics Immune Immunocompromised Host Immunohistochemistry Impaired cognition Impairment In Vitro Individual Inflammation Inflammatory Injections Knowledge Measures Mediating Mentorship Messenger RNA Methods Microglia Morphology Mus Mutation Myelin Nerve Degeneration Outcome Pathway interactions Patients Phagocytes Pharmaceutical Preparations Phenotype Phosphorylation Production Productivity Proliferating Protein Biosynthesis Protein Isoforms Proteins Public Health Research Personnel Risk Role Scientist Senile Plaques Single Nucleotide Polymorphism Stress Structural Chemistry Structure Technical Expertise Techniques Testing Thapsigargin Therapeutic Training Translations Transplantation Variant Work Xenograft procedure activating transcription factor 4 biological adaptation to stress career collaborative environment cytokine disorder risk efficacy testing enzyme activity genetic risk factor genetic variant genome wide association study humanized mouse improved in vitro activity in vivo induced pluripotent stem cell inhibitor inhibitor therapy innovation live cell imaging medical schools mouse model mutant novel novel therapeutics precursor cell protein purification response risk variant single nucleus RNA-sequencing skills stressor transcription factor transcriptomics

项目摘要

Project Summary Human genetic studies provide a powerful approach to identify genes and pathways associated with Alzheimer's disease (AD). Apolipoprotein E isoform 4 (APOE4) is the strongest genetic risk factor for sporadic Alzheimer's disease. Despite the strong effect of APOE4 on AD risk, a wide range of clinical outcomes exist within APOE4 carriers: some can develop cognitive impairment as early as 30 years of age while other carriers remain cognitively normal beyond 100 years. The large range in clinical manifestation amongst APOE4 carriers suggests that there are genetic variants that modulate APOE-associated risk. To investigate this hypothesis, we conducted stratified genome-wide association studies of APOE4 carriers at the extremes of age at onset distribution to identify variants that modify risk. We identified a single variant in EIF2B3 encoding the amino acid substitution S404A as a candidate risk modifier. eIF2B3 is a subunit of eIF2B, a guanine exchange factor (GEF) for eIF2 that is involved in translational control and the integrated stress response. Our lab has recently shown that APOE4 induces a constitutively upregulated ISR and aberrant protein translation in murine and human iPSC-derived microglia, demonstrating that APOE4 alone can lead to increased levels of cellular stress1,2. Furthermore, EIF2B2, another eIF2B subunit, is an AD risk gene identified in AD GWAS3. The overall goal of this proposal is to directly test the hypothesis that EIF2B3 variants modulate APOE4-associated risk by dysregulating the ISR and thus alter microglial cell function in the context of disease. In Aim 1, I will combine cell-free in vitro fluorescent GEF assays and structural chemistry to determine the effects of EIF2B3S404A directly on eIF2B structural integrity and enzymatic activity, in the absence of cellular stress. Aim 2 will determine the impact of EIF2B3S404A on APOE4 microglia cell function in vitro using human induced pluripotent stem cell (iPSCs)- derived microglia and live-cell imaging in the context of disease-related stressors. Lastly, in Aim 3, I will employ novel xenotransplantation methods involving direct injection of human microglia precursor cells into the mouse brain to evaluate the effect of EIF2B3S404A on APOE4 microglia cell function in vivo and in the context of disease. Together, the results here will confirm or refute the hypothesis that EIF2B3 variants modulate APOE4-associated risk by altering microglial cell function. Throughout the project, I will test the efficacy of an ISR inhibitor (ISRIB) drug at alleviating EIF2B3S404A -induced effects on EIF2B activity in vitro and in microglia in vitro and in vivo. The work here has the potential to greatly impact public health through understanding the way in which variants affect immune cell function and modify disease risk and by potentially identifying a novel drug for the treatment of AD. The fellowship training plan proposed here will provide me with the technical skills, scientific knowledge, critical thinking skills gained from Dr. Alison Goate's mentorship and the collaborative environment at the Icahn School of Medicine at Mount Sinai at large, equipping me with the necessary skills for a successful transition to a career as an independent scientist.

项目摘要人类遗传研究提供了一种强大的方法来识别与阿尔茨海默氏症相关的基因和途径疾病（AD）。载脂蛋白E同工型4（APOE4）是零星阿尔茨海默氏症的最强遗传危险因素疾病。尽管APOE4对AD风险产生了强烈的影响，但APOE4中仍然存在多种临床结果运营商：有些人早在30岁时就可以发展认知障碍，而其他承运人仍然存在认知正常超过100年。 APOE4载体之间的临床表现范围很大有一些遗传变异可以调节与APOE相关的风险。为了研究这一假设，我们进行了 APOE4载体在发作分布时极端的APOE4载体的分层全基因组关联研究确定改变风险的变体。我们在编码氨基酸取代的EIF2B3中鉴定了单个变体 S404A作为候选风险修饰符。 EIF2B3是EIF2B的亚基，EIF2B是EIF2的鸟嘌呤交换因子（GEF）参与翻译控制和综合应力反应。我们的实验室最近显示了APOE4 在鼠和人IPSC衍生的鼠标中诱导组成型上调的ISR和异常的蛋白质翻译小胶质细胞表明，仅APOE4可能会导致细胞应激水平升高1,2。此外， EIF2B2是另一个EIF2B亚基，是AD GWAS3中鉴定出的AD风险基因。该提议的总体目标是直接检验以下假设：EIF2B3变体通过失调ISR调节与APOE4相关的风险因此，在疾病的背景下改变小胶质细胞功能。在AIM 1中，我将结合无细胞的体外荧光 GEF分析和结构化学，以确定EIF2B3S404A的影响直接对EIF2B结构完整性和酶活性，在没有细胞应激的情况下。 AIM 2将确定EIF2B3S404A对使用人类诱导的多能干细胞（IPSC） - 衍生的小胶质细胞和在与疾病相关的压力源的背景下进行活细胞成像。最后，在AIM 3中，我将使用小说异种移植方法涉及直接注射人类小胶质细胞进入小鼠脑评估EIF2B3S404A对体内和疾病背景下APOE4小胶质细胞功能的影响。总之，此处的结果将确认或反驳以下假设：EIF2B3变体调节APOE4相关通过改变小胶质细胞功能的风险。在整个项目中，我将测试ISR抑制剂（ISRIB）的功效减轻EIF2B3S404A的药物在体外和体内对EIF2B活性的影响。这这里的工作有可能通过了解变体影响的方式来极大地影响公共卫生免疫细胞功能并改变疾病风险，并有可能识别出一种新的AD治疗药物。这里提出的奖学金培训计划将为我提供技术技能，科学知识，关键艾莉森·戈特（Alison Goate）博士的指导和伊坎学校（Icahn School）的协作环境所获得的思维技巧西奈山的医学作为独立科学家。