Regulation of Age-Associated Heterochromatin Formation

年龄相关异染色质形成的调节

• 批准号: 8242212
• 负责人: Jill Kreiling
• 金额: $ 11.68万
• 依托单位: BROWN UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-09-30 至 2016-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8242212
• 关键词: Address; Age; Age of Onset; Aging; Aging-Related Process; Animals; BMI1 gene; Beryllium; Binding; Bioinformatics; Biological Assay; Biology; Biology of Aging; Caloric Restriction; Cell Aging; Cells; Chromatin; Chromatin Structure; Complex; DNA Sequence Rearrangement; Data; Data Set; Deposition; Dietary Intervention; Elements; Embryo; Epigenetic Process; Extramural Activities; Fibroblasts; Fluorescence Microscopy; Functional RNA; Gene Expression; Gene Expression Profile; Gene Silencing; Genes; Genome; Genomics; Goals; Grant; Heart; Heterochromatin; Histone H2A; Histone H3; Histones; Human; Intervention; Knockout Mice; Laboratories; Lead; Lifting; Lung; Lysine; Macaca mulatta; Mammals; Mentored Research Scientist Development Award; Mentors; Methylation; MicroRNAs; Mitotic; Modification; Mus; Muscle Cells; Myocardium; Organism; PRC1 Protein; Papio; Phenotype; Physiological; Polycomb; Population; Process; Promoter Regions; Proteins; Publications; RNA; Regulation; Regulatory Element; Repression; Research; Research Personnel; Response Elements; Resveratrol; Role; Sequence Analysis; Site; Skeletal Muscle; Small RNA; Structure; Supervision; Techniques; Testing; Tissues; Training; Ubiquitination; Universities; Up-Regulation; Variant; Work; Writing; Yeasts; age related; base; career development; design; experience; feeding; genome sequencing; genome wide association study; genome-wide; insight; interest; juvenile animal; meetings; normal aging; programs; research study; skills; symposium; Address; Age; Age of Onset; Aging; Aging-Related Process; Animals; BMI1 gene; Beryllium; Binding; Bioinformatics; Biological Assay; Biology; Biology of Aging; Caloric Restriction; Cell Aging; Cells; Chromatin; Chromatin Structure; Complex; DNA Sequence Rearrangement; Data; Data Set; Deposition; Dietary Intervention; Elements; Embryo; Epigenetic Process; Extramural Activities; Fibroblasts; Fluorescence Microscopy; Functional RNA; Gene Expression; Gene Expression Profile; Gene Silencing; Genes; Genome; Genomics; Goals; Grant; Heart; Heterochromatin; Histone H2A; Histone H3; Histones; Human; Intervention; Knockout Mice; Laboratories; Lead; Lifting; Lung; Lysine; Macaca mulatta; Mammals; Mentored Research Scientist Development Award; Mentors; Methylation; MicroRNAs; Mitotic; Modification; Mus; Muscle Cells; Myocardium; Organism; PRC1 Protein; Papio; Phenotype; Physiological; Polycomb; Population; Process; Promoter Regions; Proteins; Publications; RNA; Regulation; Regulatory Element; Repression; Research; Research Personnel; Response Elements; Resveratrol; Role; Sequence Analysis; Site; Skeletal Muscle; Small RNA; Structure; Supervision; Techniques; Testing; Tissues; Training; Ubiquitination; Universities; Up-Regulation; Variant; Work; Writing; Yeasts; age related; base; career development; design; experience; feeding; genome sequencing; genome wide association study; genome-wide; insight; interest; juvenile animal; meetings; normal aging; programs; research study; skills; symposium

DESCRIPTION (provided by applicant): This application for a Mentored Research Scientist Development Award is to facilitate Dr. Jill Kreiling's transition to an independent investigator in the field of aging biology. Her long-term goals include establishing an independent research program focused on advancing our understanding of heterochromatic changes that occur during the natural aging process. To achieve these goals she will follow a structured career development and training plan that includes training practical laboratory techniques and in bioinformatic analyses; university and extramural courses; attending seminars, meetings and conferences; and training in grant writing and laboratory management skills. This plan will be implemented under the supervision of the primary mentor, Dr. John Sedivy, who is an expert in the field of aging biology and has considerable experience with the analysis of genome-wide studies. Dr. Peter Adams, a leader in the field of chromatin biology, will serve as a co-mentor, along with Dr. Robert Reenan who specializes in RNA biology. In addition, Dr. Charles Lawrence will provide guidance with the bioinformatic approach to genome-wide analyses. There is a growing body of evidence that chromatin undergoes reorganization during normal aging. This is accompanied by a corresponding change in gene expression. It is reasonable to expect that these two processes may be connected. However, the epigenetic mechanisms of this extensive rearrangement of the chromatin are virtually unknown. In this application we propose to study the mechanisms that regulate age- associated heterochromatin formation in post-mitotic tissues. Our preliminary data suggest an increase in facultative heterochromatin incorporating the highly repressive histone variant macroH2A in mouse and baboon skeletal muscle. Recent evidence points towards a role of small non-coding RNAs (ncRNAs) in the deposition of repressive heterochromatin marks. The synthesis of many miRNAs (a subclass of ncRNAs) is regulated by Polycomb group (PcG) repression, and our preliminary data suggest a decrease in PcG repression in old animals. We will study the role of ncRNAs in the regulation of age-associated heterochromatin formation in skeletal and cardiac muscle from mice and rhesus monkeys. Specifically we will correlate specific ncRNAs to sites of age associated heterochromatin formation and we will investigate the regulatory elements present in the ncRNA genes. Our hypothesis is: An age-associated reduction in PcG repression leads to activation of certain miRNA genes, whose products trigger age-associated heterochromatin formation at specific sites on the genome. Specific Aim 1: We will begin these studies by identifying the specific chromatin states that correlate with age in post-mitotic tissues. In addition, we will determine if certain dietary interventions (calorie restriction and resveratrol) can delay the onset of this age- associated phenotype. Specific Aim 2: This information will be used to design ChIP-seq assays to determine the regions of the genome susceptible to age-associated heterochromatin formation. The ncRNA populations will be characterized by RNA-seq of the transcriptome to identify ncRNAs subject to age associated increases in expression. The sequences of the ncRNAs showing an age-dependent up-regulation will be correlated with sequences of the genome showing age-associated heterochromatin to determine potential sites of RNA- dependent deposition of silencing marks. Specific Aim 3: Markers of PcG repression will be investigated to determine if there is a decrease in PcG repression with age. The promoter regions of the associated miRNA genes will be analyzed to determine if PcG repressive elements are present that could regulate expression. Finally, we will verify our results with mechanistic studies in cultured human fibroblasts to show that the expression of specific ncRNAs are repressed by PcG regulation in young cells and this repression is lifted in older cells leading to expression of the ncRNA and age-associated heterochromatin formation. Taken together this project will broaden our understanding of the mechanisms and processes involved in the regulation of age- associated heterochromatin formation. PUBLIC HEALTH RELEVANCE: As organisms age there are changes in gene expression that contribute directly to aging phenotypes. These changes in gene expression are thought to result from alterations in the structure of the chromatin to form repressive heterochromatin. We will study the regulation of chromatin structure modification to provide insight into the mechanisms of age-associated changes in gene expression and to possibly identify interventions that delay these processes.

描述（由申请人提供）：这项指导研究科学家发展奖的申请是为了促进吉尔·克雷林（Jill Kreiling）博士向衰老生物学领域的独立研究者的过渡。她的长期目标包括建立一个独立的研究计划，旨在促进我们对自然衰老过程中发生的异性变化的理解。为了实现这些目标，她将遵循结构化的职业发展和培训计划，其中包括培训实验室技术和生物信息分析；大学和校外课程；参加研讨会，会议和会议；以及赠款写作和实验室管理技能的培训。该计划将在主要导师约翰·塞维维（John Sedivy）博士的监督下实施，他是老化生物学领域的专家，并且在全基因组研究的分析方面具有丰富的经验。染色质生物学领域的领导者彼得·亚当斯（Peter Adams）博士将与专门从事RNA生物学的Robert Reenan博士一起担任同事。此外，查尔斯·劳伦斯（Charles Lawrence）博士将通过生物信息学分析的生物信息学方法提供指导。越来越多的证据表明染色质在正常衰老过程中经历重组。这伴随着基因表达的相应变化。可以合理地期望这两个过程可以连接。但是，这种广泛的染色质重排的表观遗传机制几乎是未知的。在此应用中，我们建议研究有丝分裂组织中调节年龄相关的异染色质形成的机制。我们的初步数据表明，在小鼠和狒狒骨骼肌中融合了高度抑制性组蛋白变体的辅助异染色质。最近的证据表明，小型非编码RNA（NCRNA）在抑制性异染色质标记沉积中的作用。许多miRNA（NCRNA的亚类）的合成受Polycomb组（PCG）抑制调节，我们的初步数据表明旧动物的PCG抑制作用降低。我们将研究NCRNA在小鼠和恒河猴骨骼肌和心脏肌肉中与年龄相关的异染色质形成调节中的作用。具体而言，我们将将特定的NCRNA与年龄相关的异染色质形成相关，并将研究NCRNA基因中存在的调节元件。我们的假设是：与年龄相关的PCG抑制作用导致某些miRNA基因的激活，其产物在基因组的特定部位触发与年龄相关的异染色质形成。具体目标1：我们将通过鉴定与有丝分裂后组织年龄相关的特定染色质状态开始这些研究。此外，我们将确定某些饮食干预措施（卡路里限制和白藜芦醇）是否会延迟这种相关表型的发作。具体目标2：此信息将用于设计CHIP-SEQ测定法，以确定易于与年龄相关的异染色质形成的基因组区域。 NCRNA种群的特征是转录组的RNA-seq，以鉴定受年龄相关的表达增加的NCRNA。表现出年龄依赖性上调的NCRNA的序列将与基因组的序列相关，显示与年龄相关的异染色质，以确定沉默标记的RNA依赖性沉积的潜在位点。特定目标3：将研究PCG抑制的标记，以确定PCG抑制是否随着年龄的增长而减少。将分析相关miRNA基因的启动子区域，以确定是否存在可能调节表达的PCG抑制元件。最后，我们将通过在培养的人成纤维细胞中的机械研究来验证我们的结果，以表明特异性NCRNA的表达受到年轻细胞中PCG调控的抑制，并且在较老细胞中取消了这种抑制作用，从而导致NCRNA和与年龄相关的杂型蛋白质素的形成。综上所述，该项目将扩大我们对与年龄相关异染色质形成的调节机制和过程的理解。 公共卫生相关性：随着生物的年龄，基因表达的变化直接导致衰老表型。这些基因表达的这些变化被认为是由于染色质结构的改变而导致的，形成了抑制性异染色质。我们将研究染色质结构修饰的调节，以洞悉与年龄相关的基因表达变化的机制，并可能确定延迟这些过程的干预措施。