Single-Cell Analysis of Aging-Associated 4D Nucleome in the Human Hippocampus

项目摘要/摘要 与年龄相关的认知能力下降在美国是一个重要的问题，因为大约20%的 预计到2030年，美国人口将达到65岁或以上。对分子机制的理解 因此，随着人口老龄化和人口老龄化，延长健康认知功能的大脑老化变得越来越重要 年长的人仍在劳动力大军中。脑细胞在衰老过程中表现出深刻的异质性变化 分子和细胞水平。体育锻炼的简单干预已经成为一个主要的积极因素 衰老过程中认知功能的调节剂。为了响应RFA-RM-20-005，我们已经成立了一个跨学科 拥有单细胞基因组学、神经电路和衰老方面的专业知识的团队，研究年龄和体力活动- 人死后脑海马细胞4D核组随寿命的相关变化 单元格分辨率。我们假设在人类中发生了特定细胞类型的核基因组重组 在衰老和体力活动期间的海马脑区。核糖体在控制大脑中的变化 表观基因组和转录组，调节神经回路功能。“甲基-HIC”--一种新的方法 在单细胞中DNA甲基化和染色质接触的联合图谱，结合一种超强的 高通量开放染色质和转录组的单细胞联合分析方法，将用于 询问染色质结构以及DNA甲基化、染色质可及性和基因表达 在人类的海马体中。在目标1中，我们将确定死后主要细胞类型的核基因组的变化 人的海马体具有4个年龄范围(20-39岁、40-59岁、60-79岁和80-99岁)。我们 将进一步将核组的这些变化与每种细胞类型的表观基因组和转录组相关联，以确定 衰老过程中脆弱的细胞类型，并发现可能受以下因素影响的潜在基因调控程序 衰老。在目标2中，我们将确定体育活动如何修改和恢复特定人类的核基因组 海马区细胞类型。我们将研究两个年龄匹配的认知健康队列(70-99岁)， 高水平或低水平的体力活动，由可穿戴式活动监测器测量。我们将会把恢复力 表观基因组和转录组对核组的影响。在目标3中，我们将绘制衰老和锻炼如何改变的地图 具有高度可量化体力活动的特定海马区细胞类型的核组 模型，用于与人类数据进行比较。这些小鼠研究使运动变量可以在 与其他生活方式因素的影响隔离，这些因素可能会影响海马体核组，这是 人类受试者。这项拟议的研究将有助于转变我们理解糖尿病发病机制的能力。 人类大脑老化背景下的染色质组织和功能。

Project Summary / Abstract Age-related cognitive decline is an important concern in the United States, as approximately 20% of the US population is expected to be age 65 or older by year 2030. Understanding the molecular mechansims of brain aging to prolong healthy cognitive function is therefore increasingly important as the population ages and older people remain in the work force. Brain cells exhibit profound and heterogeneous changes during aging at molecular and cellular levels. The simple intervention of physical exercise has emerged as a major positive modulator of cognitive function in aging. In response to RFA-RM-20-005, we have formed an interdisciplinary team with expertise in single-cell genomics, neural circuitry, and aging, to investigate age- and physical activity- related changes of 4D nucleome in post-mortem human brain hippocampus cells across the lifespan with single- cell resolution. We hypothesize that cell-type-specific re-organization of nucleome occurs in the human hippocampal brain region during aging and with physical activity. The changes in nucleome in turn control brain epigenome and transcriptome, modulating neural circuit functionality. The “Methyl-HiC”, a new approach for joint profiling of DNA methylation and chromatin contacts in single cells, combined with “Paired-seq”, an ultra- high-throughput method for single-cell joint analysis of open chromatin and transcriptome, will be used to interrogate the chromatin architecture along with DNA methylation, chromatin accessibility and gene expression in the human hippocampus. In Aim 1, we will determine changes in nucleome in major cell types of post-mortem human hippocampus across the life-span with 4 age ranges (20–39, 40–59, 60–79, and 80–99 years old). We will further correlate these changes in nucleome with epigenome and transcriptome in each cell type, to identify vulnerable cell types during aging, and uncover potential gene regulatory programs that could be impacted by aging. In Aim 2, we will determine how physical activity modifies and restores nucleome in specific human hippocampal cell types. We will study two age-matched cognitively–healthy cohorts (70-99 years old) with either high level or low level physical activity, as measured by wearable activity monitors. We will correlate restorative effects on nucleome with epigenome and transcriptome. In Aim 3, we will map how aging and exercise alter nucleome in specific hippocampal cell types with highly controlled quantifiable physical activity in the mouse model, for comparison with human data. These mouse studies allow the exercise variable to be investigated in isolation from effects of other lifestyle factors that can affect hippocampal nucleome, which is not possible with human subjects. The proposed research will help to transform our ability to understand the mechanisms of chromatin organization and function in the context of human brain aging.