Caloric Restriction directs topological chromatin reorganization to enter and maintain enhanced quiescence

热量限制指导拓扑染色质重组进入并维持增强的静止状态

• 批准号: 10295030
• 负责人: Elisa Enriquez Hesles
• 金额: $ 3.47万
• 依托单位: UNIVERSITY OF VIRGINIA
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-09-01 至 2023-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10295030
• 关键词: ATAC-seq; Acetate-CoA Ligase; Acetyl Coenzyme A; Address; Age; Aging; Animal Model; Architecture; Automobile Driving; Bioinformatics; Biological Models; Buffers; Caloric Restriction; Cardiovascular Diseases; Cell Cycle; Cell Death; Cell physiology; Cells; Chromatin; Chromatin Structure; Chronic Disease; Chronology; Complex; Development; Disease; Gene Activation; Gene Expression; Genes; Genetic Transcription; Glucose; Goals; Hi-C; Histone Deacetylase; Histones; Impairment; Intervention; Longevity; Maintenance; Malignant Neoplasms; Mediating; Modeling; Molecular; Nerve Degeneration; Nuclear; Nucleotides; Organizational Change; Phase; Phenotype; Population; Prevalence; Process; Production; Proteins; Psychological reinforcement; Regimen; Research; Research Personnel; Resolution; Reverse Transcriptase Polymerase Chain Reaction; Risk Factors; Role; SAGA; Saccharomyces cerevisiae; Saccharomycetales; Serine; Structure; Testing; Threonine; Training Programs; Transcription Coactivator; Transcription Repressor; XBP1 gene; Yeasts; cell age; cellular longevity; chromatin remodeling; dietary; epigenome; experimental study; healthspan; healthy aging; histone acetyltransferase; improved; insight; interest; mimetics; mutant; novel; prevent; promoter; response

PROJECT SUMMARY/ABSTRACT Aging is the leading risk factor for chronic diseases such as cardiovascular disease, cancer and neurodegeneration. As the U.S. population continues to grow older, the prevalence of these diseases will increase. Therefore, determining the mechanisms underpinning pro-longevity interventions, such as caloric restriction (CR) is an important priority. Although CR intervention improves factors contributing to cellular demise in the aging process, its impact on chromatin remodeling remains understudied. My dissertation is to understand the establishment and maintenance of quiescent chromatin architecture in the context of Saccharomyces cerevisiae chronological aging and its response to longevity interventions like CR. Understanding these changes in chromatin organization will facilitate the development of novel interventions, mimicking the beneficial effects of CR on longevity. In preliminary experiments, I have found that CR optimizes transcription conditions with abundant intracellular nucleotide, acetyl-CoA levels, and acetyl-CoA synthetase (Acs2), as cells start the transition into quiescence. I propose to elucidate the mechanism of how these conditions induce a transcriptional regulatory cascade that enhances quiescence. First in Aim 1, I will define how CR temporally and structurally enhances chromatin compaction as cells enter quiescence. Second, I will test the hypothesis that CR induces the early wave of transcription via acetyl-CoA accumulation by Acs2. This accumulation then results in histone hyperacetylation at relevant target promoters by Gcn5 histone acetyltransferase complex (SAGA). Third, I will test the contribution of nucleotide buffering to transcription and the later establishment of repressive chromatin in quiescence. These studies will provide mechanistic insights of CR's role in establishing quiescence during chronological aging. Chromatin compaction is vital to maintaining quiescence, yet the architectural changes that occur during aging or in response to CR are unknown. Therefore, in Aim 2, I will characterize the maintenance of repressive chromatin structure during chronological aging. I hypothesize that transcriptional repressors and chromatin architectural proteins become depleted with age, and thus detrimental to quiescence. First, I will detect breakdown of repressive chromatin structure in aged cells and its effect on transcription using a combination of ATAC-Seq and PRO-Seq. Second, I will characterize the depletion of chromatin factors in CLS using tandem mass tagging (TMT) experiments. Third, I will determine if chromatin openness during quiescence drives cell cycle re-entry or cell death in snf1∆ and gcn5∆ mutants. These experiments will define CR's impact on the temporal and structural maintenance of repressive chromosomal architecture during aging.

项目摘要/摘要 衰老是慢性疾病的主要危险因素，例如心血管疾病，癌症和 神经变性。随着美国人口不断增长，这些疾病的患病率将 增加。因此，确定基于促伦格的干预措施的机制，例如热量 限制（CR）是重要的优先事项。尽管CR干预改善了导致细胞灭亡的因素 在衰老过程中，其对染色质重塑的影响仍被了解。我的论文是理解 在糖疗法的背景下建立和维护静态染色质体系结构 酿酒酵母的年代老化及其对CR等寿命干预措施的反应。了解这些变化 在染色质中，组织将促进新干预的发展，模仿有益的效果 长寿的Cr。 在初步实验中，我发现CR优化了具有丰富细胞内的转录条件 随着细胞开始过渡到静止，核苷酸，乙酰-COA水平和乙酰-COA合成酶（ACS2）。我 提议阐明这些条件如何引起转录调节级联的机制 增强静止。首先，在AIM 1中，我将定义CR暂时和结构增强染色质的方式 当细胞进入静止时，压实。其次，我将测试Cr诱导早期浪潮的假设 通过ACCS2通过乙酰辅酶A积累的转录。然后，这种积累导致在 GCN5组蛋白乙酰转移酶复合物（SAGA）的相关靶启动子。第三，我将测试贡献 核丁基缓冲至转录，后来在静止中建立反射性染色质。这些 研究将提供有关CR在年代老化期间建立静止的作用的机理见解。 染色质压实对于保持静止至关重要，但是在衰老期间发生的结构变化 或响应CR是未知的。因此，在AIM 2中，我将表征反光的维护 年代老化期间的染色质结构。我假设转录表示和染色质 建筑蛋白随着年龄的增长而加深，因此对静止有害。首先，我会发现 老化细胞中反射性染色质结构的分解及其对转录的影响，结合 Atac-Seq和Pro-Seq。其次，我将使用串联来表征Cls中染色质因子的耗竭 质量标记（TMT）实验。第三，我将确定静止期间的染色质开放度驱动细胞 SNF1Δ和GCN5Δ突变体中的循环重新进入或细胞死亡。这些实验将定义CR对 衰老过程中反射性染色体结构的临时和结构维护。