Computational evaluation of the causal role of somatic mutations in human aging

体细胞突变在人类衰老中因果作用的计算评估

• 批准号: 9856241
• 负责人: Xiao Dong
• 金额: $ 9.52万
• 依托单位: ALBERT EINSTEIN COLLEGE OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-09-15 至 2020-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9856241
• 关键词: Computational; evaluation; causal; role; somatic

Project Abstract Although genome instability has long been considered as one of the major causal factors of aging, little is known about the actual number of genome alterations per cell and their effects on aging organisms, most notably humans. In the research proposed here I will take a single cell approach to identify the most common types of somatic mutations, i.e., base substitutions, small INDELS, copy number variation, genome structural variation and retrotranspositions, in human B lymphocytes as a function of age. The overarching goal is then to estimate functional effects of these DNA mutations accumulated during human aging in this particular cell type, which will also serve as a model for studying somatic mutations and their consequences in other cell types. This could never be tested before, because it was never possible to analyze random somatic mutations in a tissue by sequencing bulk DNA from that tissue (mutations are low- abundant), I will achieve this goal by utilizing a new, single-cell, whole genome sequencing (SCWGS) protocol that we developed. In this project I will focus on human B lymphocytes from individuals varying in age from about 30 to over 100 years and determine the genome-wide frequency and location of the different types of mutations in multiple cells from each individual (Aim 1). Preliminary results already show a significant increase of both base substitution mutations and CNVs with age, with a substantial number of these mutations in B cell genomic regions that are potentially functional. Hence, in Aim 2 I will predict the actual functional effects of these potentially functional, age-related mutations using machine learning approaches and integrative network analysis. Finally, in Aim 3 I will empirically test these predictions as to whether the mutation loads observed affect B cell's ability of response to stimulus. Hence, to test the long-standing hypothesis of genome instability as a causal factor in aging ,I will determine age-related mutations in single cells at four levels: (1) number of mutations, mutation spectra and genome distribution in individual cells; (2) potential functional effects of individual mutations, i.e., non-synonymous mutations in exons and mutations in gene regulatory regions; (3) mutations collectively affecting the gene regulatory network; and (4) relationship between mutation load and B cell activation status. In summary, the results of the proposed project will, for the first time uncover possible direct functional effects of somatic mutations on cellular function.

项目摘要 尽管长期以来一直认为基因组不稳定性是衰老的主要因素之一，但很少 知道每个细胞的实际基因组改变及其对衰老生物的影响，大多数 特别是人类。在这里提出的研究中，我将采用一种单元格的方法来识别最常见的 体细胞突变的类型，即基础取代，小indels，拷贝数变化，基因组结构 人类B淋巴细胞中的变异和逆转序列与年龄的关系。总体目标是 估计这些DNA突变在此期间积累的这些DNA突变的功能效应 特定的细胞类型，这也将作为研究体突变及其它们的模型 其他细胞类型的后果。以前永远无法测试这一点，因为它永远不可能 通过对组织中的大量DNA进行测序（突变很低，分析组织中的随机体细胞突变 丰富的），我将通过使用新的单细胞，整个基因组测序（SCWGS）协议来实现这一目标 我们发展了。在这个项目中，我将重点介绍来自年龄不同的个体的人类B淋巴细胞 大约30到100多年，并确定不同类型的全基因组频率和位置 来自每个个体的多个细胞中的突变（AIM 1）。初步结果已经显示出显着增加 碱基取代突变和年龄的CNV，其中大量这些突变在B细胞中 潜在功能的基因组区域。因此，在目标2中，我将预测 使用机器学习方法和集成网络的这些潜在功能性，与年龄相关的突变 分析。最后，在AIM 3中，我将对是否观察到突变负载进行经验测试这些预测 影响B细胞对刺激的反应能力。因此，测试基因组不稳定性的长期假设 作为衰老的因果因素，我将确定单个细胞中与年龄相关的突变四个级别：（1）数量 单个细胞中的突变，突变光谱和基因组分布； （2） 个体突变，即外显子中非同义突变和基因调节区域的突变； （3） 共同影响基因调节网络的突变； （4）突变负荷与B之间的关系 细胞激活状态。总而言之，拟议项目的结果将首次发现 体细胞突变对细胞功能的直接功能作用。