Altered reverse transcriptase-dependent gene diversification mechanisms in Alzheimer's disease brains

阿尔茨海默病大脑中逆转录酶依赖性基因多样化机制的改变

基本信息

批准号：
10550208
负责人：
JEROLD CHUN
金额：
$ 92.97万
依托单位：
SANFORD BURNHAM PREBYS MEDICAL DISCOVERY INSTITUTE
依托单位国家：
美国
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-04-01 至 2025-01-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10550208
关键词：
Affect Alzheimer&apos s Disease Alzheimer&apos s disease brain Alzheimer&apos s disease therapeutic Alzheimer&apos s disease therapy Amyloid beta-Protein Precursor Animal Experiments Animal Model Autopsy Back Biological Models Brain Brain region Cell model Complementary DNA Copy Number Polymorphism DNA DNA strand break Data Disease Down Syndrome FDA approved Female Foundations Gene Proteins Genes Genetic Recombination Genetic Transcription Genome Genomics HIV Human IACUC In Situ Hybridization Institutional Review Boards Knowledge Methodology Modeling Molecular Molecular Biology Molecular Neurobiology Molecular Target Mosaicism Nature Neurofibrillary Tangles Neuroglia Neurons Nucleotides Pathogenicity Patients Pattern Prevalence Publishing RNA RNA-Directed DNA Polymerase Reporting Reverse Transcriptase Inhibitors Role Sampling Senile Plaques Testing Therapeutic Toxic effect Validation Variant aged brain tissue cell type ds-DNA familial Alzheimer disease genetic variant human embryonic stem cell induced pluripotent stem cell integration site male mosaic nanobodies neurobiological mechanism neuropathology new therapeutic target novel sequencing platform sex therapeutic target

项目摘要

PROJECT SUMMARY/ABSTRACT We have identified somatic gene recombination (SGR) in neurons of the human brain, with particular relevance to sporadic Alzheimer’s disease (SAD) (Nature 563, 639-645 (2018)). This discovery represents a new and functionally significant aspect of genomic mosaicism (eLife;4:e05116 (2015)) that has genuine therapeutic potential through newly identified molecular targets. Indeed, we found that SGR, acting on the AD gene for Amyloid Precursor Protein (APP), produces thousands of distinct forms of APP, some of which are enriched in or unique to AD. The APP gene variations related to AD that were analyzed thus far include copy number variations (CNVs) and at least 11 single-nucleotide variations (SNVs) that were previously reported as pathogenic in familial AD, yet that arose somatically and mosaically in SAD; these variations were absent from non-diseased neurons. SGR utilizes reverse transcriptase (RT) activity on transcribed RNAs that, combined with DNA strand-breaks and APP gene transcription, produce double-stranded DNA that is retro-inserted back into the genome to form “genomic cDNAs” (gencDNAs). These published data contribute to the scientific foundation on which the current proposal will build, to test the hypothesis that altered SGR, involving brain- specific reverse transcriptases, functionally contributes to AD and affects multiple genes, providing novel targets for AD therapies. Postmortem IRB-approved and de-identified brain samples from validated AD donors of both sexes will be compared to non-diseased controls, while IACUC-approved animal experiments will model SGR and its AD-relevant endpoints. Three Aims will be pursued over 5 years. Aim 1 will define the molecular neurobiology of APP gencDNA diversity and identify new SGR genes enhanced in AD brains. Aim 2 will determine expression and function of SGR genes in AD brain and model systems. Aim 3 will identify genes responsible for RT SGR activity within normal and AD brains. This proposal will thus open new vistas into AD via novel SGR mechanisms and will identify new therapeutic targets for the treatment of AD.

项目概要/摘要我们已经在人脑神经元中发现了体细胞基因重组（SGR），具有特别的相关性散发性阿尔茨海默病 (SAD)（Nature 563, 639-645 (2018)）这一发现代表了一项新的发现。基因组嵌合体的功能重要方面（eLife；4：e05116（2015））具有真正的治疗作用事实上，我们发现 SGR 作用于 AD 基因。淀粉样前体蛋白 (APP) 可产生数千种不同形式的 APP，其中一些富含迄今为止分析的与 AD 相关的 APP 基因变异包括拷贝数。变异（CNV）和至少 11 个单核苷酸变异（SNV），这些变异之前被报道为在家族性 AD 中具有致病性，但在 SAD 中却以体细胞和镶嵌方式出现这些变异； SGR 利用转录 RNA 的逆转录酶 (RT) 活性，将其结合起来。通过 DNA 链断裂和 APP 基因转录，产生逆向插入的双链 DNA 这些已发表的数据对科学做出了贡献。当前提案将在此基础上建立，以测试改变 SGR 的假设，涉及脑- 特定的逆转录酶，在功能上有助于 AD 并影响多个基因，提供新的靶标用于 AD 疗法的尸检 IRB 批准且已去识别的大脑样本来自经过验证的 AD 捐赠者。性别将与未患病对照进行比较，而 IACUC 批准的动物实验将模拟 SGR 其与 AD 相关的目标将在 5 年内实现，目标 1 将定义分子。 APP gencDNA 多样性的神经生物学并鉴定 AD 大脑中增强的新 SGR 基因。确定 AD 大脑和模型系统中 SGR 基因的表达和功能。负责正常和 AD 大脑内的 RT SGR 活动，因此该提议将为 AD 开辟新的前景。通过新颖的 SGR 机制，并将确定治疗 AD 的新治疗靶点。