The role of CELF2 and its genetic variants in Alzheimer's disease

CELF2及其遗传变异在阿尔茨海默病中的作用

• 批准号: 10334445
• 负责人: Lizhen Chen
• 金额: $ 45.11万
• 依托单位: UNIVERSITY OF TEXAS HLTH SCIENCE CENTER
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-02-01 至 2026-01-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10334445
• 关键词: Adult; Affect; Age; Aging; Alleles; Alternative Splicing; Alzheimer' s Disease; Alzheimer' s disease brain; Alzheimer' s disease model; Alzheimer' s disease pathology; Alzheimer' s disease patient; Alzheimer' s disease risk; Animal Model; Animals; Autopsy; Behavior; Behavioral; Binding; Biochemical Genetics; Brain; Brain region; Caenorhabditis elegans; Clustered Regularly Interspaced Short Palindromic Repeats; Cognition; Data; Defect; Dementia; Deposition; Disease; Elderly; Environmental Risk Factor; Exons; Family; Genes; Genetic; Genetic Polymorphism; Genetic Screening; Genomics; Health; High-Throughput Nucleotide Sequencing; Hippocampus (Brain); Homologous Gene; Human; Human Genetics; Immunohistochemistry; Immunoprecipitation; Impaired cognition; Individual; Induced pluripotent stem cell derived neurons; Institutes; Introns; Knock-in; Knock-out; Knockout Mice; Late Onset Alzheimer Disease; Learning; Longevity; MAPT gene; Mammals; Measures; Memory; Messenger RNA; Microtubules; Minor; Modeling; Mus; Mutation; Nerve Degeneration; Nervous system structure; Neurodegenerative Disorders; Neurons; Pathogenesis; Pathology; Patients; Phenotype; Play; Protein Isoforms; Proteins; Publishing; RNA Splicing; RNA Stability; RNA-Binding Proteins; Regulation; Reporting; Research; Risk Factors; Role; Sampling; Single Nucleotide Polymorphism; Spinal Muscular Atrophy; Tauopathies; Techniques; Testing; Tissues; Work; brain cell; calmodulin-dependent protein kinase II; cell type; conditional knockout; crosslink; crosslinking and immunoprecipitation sequencing; experience; genetic analysis; genetic association; genetic variant; genome wide association study; hTau Mice; high risk; improved; induced pluripotent stem cell; insight; knock-down; mRNA Expression; member; mouse model; mutant; neurotoxicity; new therapeutic target; overexpression; potential biomarker; presenilin-1; presenilin-2; protective effect; protein expression; risk variant; tau Proteins; tau expression; therapeutic target; transcriptome sequencing

Age is the most important risk factor for Alzheimer's disease (AD), but the occurrence of this disease is also affected by environmental factors, individual experience and genetic pre-deposition. Genetic factors are well established to play an important role in risk of AD. CELF2, an RNA binding protein that regulates alternative splicing and RNA stability, has been recently identified as a risk factor associated with AD. Polymorphisms in CELF2 are significantly associated with high-risk alleles of APOE, and the “A” allele of SNP rs2242451 is associated with reduced AD risk. CELF2 is highly expressed in the nervous system, and enhanced neuronal CELF2 expression levels have been found in various neurodegeneration models and human patients. We generated a conditional knockout mouse Celf2 allele. Our preliminary data suggest that deleting Celf2 in adult brain has beneficial effects, including improved learning and memory. We identified mRNA targets of mouse CELF2 (using CLIP-seq; cross-linking immunoprecipitation high-throughput sequencing) and found that CELF2 binds to introns around the alternatively spliced exons of a set of AD- regulated genes, including APP, MAPT (Tau), PSEN1, PSEN2, and BIN1, suggesting a key role of CELF2 in regulating alternative splicing of AD-related genes. Alternative splicing of these AD-related genes is known to regulate AD pathogenesis. For example, alternative splicing of exon 10 of the tau mRNA gives rise to protein isoforms with three (3R) or four (4R) microtubule binding repeats. Imbalances in 4R: 3R ratio alone have been reported sufficient to induce the pathogenesis of AD in a human-Tau mouse model. Taken together with the genetic association between CELF2 SNP and reduced AD risk in humans, we hypothesize that CELF2 expression is up-regulated in AD brains and loss of CELF2 in adult brains is sufficient to rescue AD-related phenotypes. In Specific Aim 1, we will test whether loss of CELF2 can suppress AD-related phenotypes in C. elegans AD models. In Specific Aim 2, we will test whether loss of CELF2 in the adult brain is protective through regulating alternative splicing using AD mouse models. In Specific Aim 3, we will test whether CELF2 expression is increased in AD brains using postmortem human samples and ask if the AD risk-reducing SNP down regulates CELF2 expression or inhibits its function using human iPSC-derived neurons. We have obtained postmortem brain samples and established a strong research team with expertise in genetics, genomics, postmortem AD brains and iPSC. Data from the proposed work will provide important mechanistic insights that go well beyond published human genetic analyses and ultimately yield new therapeutic targets for the treatment of AD.

年龄是阿尔茨海默病（AD）最重要的危险因素，但这种疾病的发生是 还受环境因素、个人经历和遗传预沉积的影响。遗传因素是 在AD风险中发挥重要作用。CELF 2是一种RNA结合蛋白， 选择性剪接和RNA稳定性，最近已被确定为与AD相关的风险因素。 CELF 2基因多态性与APOE的高危等位基因显著相关，SNP的“A”等位基因与APOE的高危等位基因显著相关。 rs 2242451与AD风险降低相关。CELF 2在神经系统中高度表达， 已经在各种神经变性模型中发现神经元CELF 2表达水平增强， 人类病人我们产生了条件性敲除小鼠Celf 2等位基因。我们的初步数据显示， 在成人大脑中删除Celf 2具有有益的效果，包括改善学习和记忆。我们确定 小鼠CELF 2的mRNA靶标（使用CLIP-seq;交联免疫沉淀高通量 测序），并发现CELF 2结合到一组AD-1基因的可变剪接外显子周围的内含子。 调节基因，包括APP，MAPT（Tau），PSEN 1，PSEN 2和BIN 1，表明CELF 2在 调节AD相关基因的选择性剪接。已知这些AD相关基因的选择性剪接 调节AD发病机制。例如，tau mRNA的外显子10的选择性剪接产生蛋白质 具有三个（3R）或四个（4 R）微管结合重复的同种型。仅4 R：3R比率的不平衡就已被 据报道，在人-Tau小鼠模型中足以诱导AD的发病机制。再加上 CELF 2 SNP与人类AD风险降低之间的遗传关联，我们假设CELF 2 在AD脑中表达上调，成年人脑中CELF 2的缺失足以挽救AD相关的脑损伤。 表型在具体目标1中，我们将测试CELF 2的缺失是否可以抑制C. elegans AD models.在具体目标2中，我们将测试成人大脑中CELF 2的缺失是否具有保护作用。 通过使用AD小鼠模型调节可变剪接。在具体目标3中，我们将测试CELF 2是否 使用死后人类样本在AD大脑中表达增加，并询问AD风险降低SNP是否 使用人iPSC衍生的神经元下调CELF 2表达或抑制其功能。我们有 获得了死后的大脑样本，并建立了一个强大的研究团队，拥有遗传学方面的专业知识， 基因组学、AD死后大脑和iPSC。从拟议的工作数据将提供重要的机制 这些见解远远超出了已发表的人类遗传分析，并最终产生新的治疗靶点， AD的治疗。