Epigenetic Changes with Age in Hematopoietic Stem Cells

描述（由申请人提供）：表观基因组中的改变已被证明是发育和分化中基因表达的调节层。染色质修饰和DNA甲基化在这些过程中都很重要。关于衰老中的这些变化知之甚少，但从实验室对其中一种Co-PI（EM）进行的研究中，已经记录了肝脏和黑素细胞随年龄的变化。该申请汇集了一个多学科团队，以生成与基因表达的激活和抑制相关的染色质修饰的全球基因组范围图以及DNA中胞苷甲基化位点的全球图。DNA甲基化已被证明与染色质修饰的相关性大于与特定DNA序列的相关性。我们建议对小鼠造血干细胞（HSC）进行这些研究，Co-PI（MG）已显示出年轻小鼠和老年小鼠之间的基因表达发生显着变化，以及移植到致死性照射受体后移植能力降低。将使用高通量测序生成图谱，其提供核苷酸水平区分。此外，为了测试IGF 1通路在染色质修饰中的作用，我们将检查来自长寿小鼠模型，生长激素释放激素受体突变体，小小鼠的HSC。此外，将研究的老龄化社区感兴趣的第二个模型是过早衰老综合征，其中p53蛋白稳定，动物寿命缩短，具有加速衰老的特征。这些研究产生的数据将成为老龄化社区的资源，并将通过NCBI基因表达综合网站提供给科学界。这笔赠款将使四个新的人员招聘，可以在两年内完成，从而实现ARRA方案的目标之一。 公共卫生相关性：该应用程序将生成造血干细胞表观基因组随年龄变化的数据，并将立即向科学界发布。该项目需要高通量技术和一个多学科的研究团队。该补助金将通过雇用目前不在研究人员实验室工作的四个人来响应ARRA指南。

DESCRIPTION (provided by applicant): Alterations in the epigenome have been shown to be a layer of regulation of gene expression in development and differentiation. Both chromatin modifications and DNA methylation are important in these processes. Relatively little is known about these changes in aging, but from studies done in the laboratory of one of the Co-PIs (EM), alterations in the liver and in melanocytes with age have been documented. This application brings together a multi- disciplinary team to generate a global, genome wide map of chromatin modifications associated with both activation and repression of gene expression as well as a global map of cytidine methylation sites in the DNA. DNA methylation has been shown to have more of a correlation with chromatin modifications than with specific DNA sequence. We propose to carry out these studies on murine hematopoietic stem cells (HSC) which have been shown by the Co-PI (MG) to have significant changes in gene expression between young and old mice as well as reduced ability to engraft upon transplantation to lethally irradiated recipients. The maps will be generated using high throughput sequencing which gives nucleotide level discrimination. Further, to test the role of the IGF1 pathway in chromatin modification, we will examine the HSC from a long lived mouse model, the growth hormone releasing hormone receptor mutant, the Little mouse. In addition, a second model of interest to the aging community that will be studied is the premature aging syndrome in which the p53 protein is stabilized and the animals have a shortened lifespan with accelerated characteristics of aging. Data generated from these studies will be a resource for the aging community and will be made available to the scientific community through the NCBI Gene Expression Omnibus site. This grant will enable the recruitment of four new personnel and can be completed within two years thus fulfilling one of the goals of the ARRA program. PUBLIC HEALTH RELEVANCE: This application will generate data on the epigenome of hematopoietic stem cells with age which will be released to the scientific community immediately. This project requires high throughput technology and a team of multidisciplinary investigators. The grant will respond to the ARRA guidelines by employing four individuals not currently working in the laboratories of the investigators.