Epigenetic Reprogramming of Cellular Age

细胞年龄的表观遗传重编程

• 批准号: 10195469
• 负责人: THOMAS A. RANDO
• 金额: $ 42.6万
• 依托单位: PALO ALTO VETERANS INSTIT FOR RESEARCH
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-05-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10195469
• 关键词: ATAC-seq; Acceleration; Address; Affect; Age; Aging; Biological; Biological Assay; Blood; Cell Aging; Cell Communication; Cells; ChIP-seq; Characteristics; Complement; DNA Methylation; Data; Enzymes; Epigenetic Process; Exhibits; Exposure to; Generations; Genetic; Genetic Transcription; Genetic study; Goals; Heterochromatin; Histones; Homeostasis; In Vitro; Intervention; Knock-out; Laboratory Animals; Liver; Longevity; Lysine; Mediating; Mediator of activation protein; Methylation; Methyltransferase; Molecular; Molecular Mechanisms of Action; Molecular Profiling; Mus; Muscle; Muscle Cells; Muscle satellite cell; Nucleosomes; Parabiosis; Pathway interactions; Pharmacology; Pharmacology Study; Phenotype; Plasma; Population; Process; Protocols documentation; Publishing; Rejuvenation; Reporting; Role; Serum; System; Testing; Tissues; age effect; aged; base; cell age; cell growth regulation; demethylation; epigenome; experimental study; histone demethylase; histone methyltransferase; histone modification; in vitro Model; in vivo; in vivo evaluation; induced pluripotent stem cell; inhibitor/antagonist; interest; methylation pattern; muscle aging; repaired; response; restoration; single-cell RNA sequencing; stem cell aging; tool; transcriptome

PROJECT SUMMARY Current ideas that systemic factors regulate the aging of cells and tissues, in terms of both promoting and reversing the aging process, have emerged from studies of heterochronic parabiosis (HP) and heterochronic blood exchange (HBE) protocols. Our lab performed the first HP studies in order to assess cellular aging and rejuvenation as it relates to tissue homeostasis and repair and in terms of molecular determinants of cellular age. Initially, we focused changes in muscle stem cells (MuSCs), but we and others later explored these phenotypic changes in many different cell populations. Since then, we have explored the molecular mechanisms by which systemic factors might influence the aging process. Based on numerous lines of evidence, we have hypothesized that the alteration in cellular aging features is due to a form of epigenetic reprogramming that is akin to that which occurs during induced pluripotent stem cell generation but without the loss of cellular differentiation. A general feature of cellular aging is the loss of heterochromatin and subsequent dysregulation of transcriptional stability. Heterochromatin is prominently associated with specific histone modifications, most notably by di- and tri-methylation of lysine 9 on histone 3 (H3K9me2 and H3K9me3, respectively). In Preliminary Studies, we have shown the H3K9me3 and heterochromatin can be regulated in MuSCs, with loss of both leading to features seen in aging cells. Based on these data and related published findings, the primary hypothesis of this proposal is that a primary mediator of HP and HBE transposition of aging phenotypes to young and old cells is the regulation of the cellular epigenome, and with a specific focus on H3K9 methylation and heterochromatin formation. To test this hypothesis, this proposal is divided into three Specific Aims. Aim 1: To assess the transcriptional and epigenetic signature of MuSCs in response to HP. We will establish HP and control pairs, and we will assess the MuSC molecular signatures compared to control mice in assays of the transcriptome and the epigenome. Aim 2: To examine the epigenetic mechanisms underlying the transposition of aging phenotypes in MuSCs. Using genetic and pharmacologic tools, we will modulate H3K9 methylation in young and old MuSCs exposed to young or old serum in vitro. We will test for the effect of changes in H3K9 methylation on the phenotypic changes of MuSCs previously described in response to heterochronic serum exposure. Aim 3: To test in vivo for the essential roles of H3K9 methyltransferase and demethylase activities in mediating the effects of HP on MuSCs. We will use genetic and pharmacologic tools to modulate H3K9 methylation in MuSCs in vivo. We will assess epigenetic and heterochromatin status, as well as the functional changes in MuSCs in response to HP. Together, these studies will elucidate molecular mechanisms of epigenetic programming of age in response to HP and HBE.

项目概要 目前的观点认为，系统因素在促进和促进细胞和组织衰老方面发挥着调节作用。 逆转衰老过程，是从异时性联体共生（HP）和异时性 血液交换（HBE）协议。我们的实验室进行了首次 HP 研究，以评估细胞衰老和 再生，因为它与组织稳态和修复以及细胞年龄的分子决定因素有关。 最初，我们关注的是肌肉干细胞 (MuSC) 的变化，但我们和其他人后来探索了这些表型 许多不同细胞群的变化。从那时起，我们就开始探索其分子机制。 系统因素可能会影响衰老过程。根据大量证据，我们假设 细胞衰老特征的改变是由于一种类似于表观遗传重编程的形式 发生在诱导多能干细胞生成期间，但不丧失细胞分化。 细胞衰老的一个普遍特征是异染色质的丧失以及随后的染色质失调 转录稳定性。异染色质与特定组蛋白修饰显着相关，大多数 特别是通过组蛋白 3 上赖氨酸 9 的二甲基化和三甲基化（分别为 H3K9me2 和 H3K9me3）。初步阶段 研究表明，H3K9me3 和异染色质可以在 MuSC 中受到调节，同时丢失两个主要的 老化细胞中所见的特征。根据这些数据和相关已发表的研究结果，主要假设 该提议认为 HP 和 HBE 是衰老表型向年轻和老年细胞转位的主要介质 是细胞表观基因组的调节，特别关注 H3K9 甲基化和异染色质 形成。 为了检验这一假设，该提案分为三个具体目标。目标 1：评估转录 以及 MuSCs 对 HP 的反应的表观遗传特征。我们将建立 HP 和对照对，并且我们将评估 在转录组和表观基因组分析中将 MuSC 分子特征与对照小鼠进行比较。 目标 2：研究 MuSC 衰老表型转座背后的表观遗传机制。 使用遗传和药理学工具，我们将调节暴露的年轻和年老 MuSC 中的 H3K9 甲基化 体外年轻或年老的血清。我们将测试 H3K9 甲基化的变化对表型的影响 先前描述的 MuSC 响应异时血清暴露的变化。目标 3：体内测试 H3K9 甲基转移酶和去甲基酶活性在介导 HP 影响中的重要作用 MuSC。我们将使用遗传和药理学工具来调节体内 MuSC 中的 H3K9 甲基化。我们将 评估表观遗传和异染色质状态，以及 MuSC 响应 HP 的功能变化。 总之，这些研究将阐明年龄响应的表观遗传编程的分子机制。 惠普和HBE。