Elucidating AD genotype-phenotype relationships using genetics of human IPS cells

利用人类 IPS 细胞遗传学阐明 AD 基因型-表型关系

• 批准号: 8758050
• 负责人: Lawrence S. Goldstein
• 金额: $ 193.6万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN DIEGO
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-08-15 至 2019-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8758050
• 关键词: Address; Alzheimer' s Disease; Astrocytes; Biochemical; Candidate Disease Gene; Cell Line; Cell model; Cells; Clinical Data; Data; Diagnostic; Disease; Disease Pathway; Down Syndrome; Elements; Endocytosis; Event; Exhibits; Frequencies; Gene Expression; Genes; Genetic; Genome; Genomics; Genotype; Heritability; Human; Human Genetics; In Vitro; Individual; Lesion; Light; Link; Modeling; Mutation; Neuroglia; Neurons; Pathology; Pathway interactions; Patients; Phenotype; Play; Population; Research; Risk Factors; Role; Site; Testing; Therapeutic; Variant; Work; cell type; disease phenotype; familial Alzheimer disease; gene function; genetic risk factor; genetic variant; genome wide association study; induced pluripotent stem cell; presenilin; public health relevance; research study; secretase; social; stem cell technology; tau Proteins; tau phosphorylation; therapy development; trafficking

DESCRIPTION (provided by applicant): Alzheimer's disease (AD) is common, devastating, and creates enormous social and financial burdens. At present, no effective disease-modifying AD treatment is available or imminent, in part because we lack a complete understanding of the cellular mechanisms and pathways that fail in human neurons and glial cells during disease, and in part because we don't adequately understand how common genetic variants alter human neuronal and glial phenotypes. Here we propose to test whether APP and PS mutations generated in common genetic backgrounds in human induced pluripotent stem cells (hIPSC) generate the same early neuronal phenotypes and then to investigate the extent to which a candidate set of genes identified by GWAS studies generate comparable phenotypes when reduced, increased, or altered by naturally occurring variants. To tackle both problems, we propose unique applications of hIPSC technology to 1) dissect how FAD mutations alter key pathways and then 2) to test how individual genetic background and identified risk factors predispose to SAD biochemical phenotypes in human neurons and astrocytes. Where possible, we will link the in vitro information to clinical data on individual patients and to post-mortem pathology from the UCSD ADRC. The analysis of hIPSC lines from SAD patients will be crucial to probe how common genetic risk factors act in neurons and astrocytes and will also give an initial estimate of the frequency of genomes in SAD patients and controls that cause relevant SAD phenotypes in neural cells differentiated in vitro. This frequency estimate will help address the important long-term question of whether hIPSC lines can be used to predict the likelihood that a given individual will develop SAD, i.e., to generate a predictive genomic/hIPSC diagnostic for SAD. This proposal capitalizes upon previous work from us and others that analyzed hIPSC lines from patients carrying an APP duplication (APPDp) or trisomy 21. Both situations appear to cause FAD by increasing APP expression by 50% in an otherwise euploid genome. Neurons made from these hIPSC lines exhibit typical AD biochemical alterations including elevated A¿, elevated activation of GSK3, and elevated phosphorylation of tau at a proposed pathological site. We also found that APPV717F but not PS1dE9 mutations cause elevated p-tau levels. Thus, early neuronal phenotypes of APP and presenilin mutations might be different raising the possibility that there may be multiple early pathogenic pathways that can be studied using hIPSC technology. We also found that hIPSC studies can elucidate how one common genetic risk factor, SORL1, acts in human neurons. We thus propose three specific aims: 1) Test the hypothesis that APP, PS1, and ¿-secretase mutations trigger the same early events in human neurons and astrocytes leading to downstream biochemical pathology typical of AD. 2) Test the hypothesis that genes identified as risk factors in GWAS studies generate AD phenotypes and altered endocytosis, trafficking, or transport when over or underexpressed. 3) Test the hypothesis that common genetic variants identified in GWAS studies act by altering gene expression in neurons or astrocytes.

描述（由申请人提供）：阿尔茨海默病（AD）是一种常见的、毁灭性的疾病，造成了巨大的社会和经济负担。目前，没有有效的改变疾病的阿尔茨海默病治疗方法可用或迫在眉睫，部分原因是我们缺乏对人类神经元和神经胶质细胞在疾病期间失效的细胞机制和途径的完整了解，部分原因是我们没有充分了解常见的遗传变异如何改变人类神经元和神经胶质表型。在这里，我们建议测试在人类诱导多能干细胞（hIPSC）中共同遗传背景下产生的APP和PS突变是否产生相同的早期神经元表型，然后研究GWAS研究确定的一组候选基因在被自然发生的变异减少、增加或改变时产生相似表型的程度。为了解决这两个问题，我们提出了独特的hIPSC技术应用，以1)剖析FAD突变如何改变关键途径，然后2)测试个体遗传背景和确定的风险因素如何易患人类神经元和星形胶质细胞中的SAD生化表型。在可能的情况下，我们将把体外信息与个体患者的临床数据和UCSD ADRC的死后病理学联系起来。对SAD患者的hIPSC细胞系的分析对于探索常见遗传风险因素如何在神经元和星形胶质细胞中起作用至关重要，也将初步估计SAD患者基因组的频率，并在体外分化的神经细胞中引起相关SAD表型的控制。这种频率估计将有助于解决一个重要的长期问题，即hIPSC系是否可以用于预测特定个体患SAD的可能性，即为SAD产生预测性基因组/hIPSC诊断。该提案利用了我们和其他人之前的工作，分析了来自携带APP重复（APPDp）或21三体的患者的hIPSC系。这两种情况似乎都是通过在其他整倍体基因组中增加50%的APP表达来引起FAD的。由这些hIPSC细胞系制成的神经元表现出典型的AD生化改变，包括A¿升高，GSK3激活升高，以及拟议病理部位tau磷酸化升高。我们还发现APPV717F突变而非PS1dE9突变导致p-tau水平升高。因此，APP和早老素突变的早期神经元表型可能不同，这就提出了利用hIPSC技术研究多种早期致病途径的可能性。我们还发现hIPSC研究可以阐明一个常见的遗传风险因子SORL1如何在人类神经元中起作用。因此，我们提出了三个具体目标：1)验证APP、PS1和¿-分泌酶突变在人类神经元和星形胶质细胞中触发相同的早期事件，导致AD典型的下游生化病理的假设。2)验证在GWAS研究中被确定为危险因素的基因在过度或过低表达时产生AD表型和改变内吞作用、运输或运输的假设。3)验证GWAS研究中发现的常见遗传变异通过改变神经元或星形胶质细胞中的基因表达而起作用的假设。