Exploring the sequence identity of cytoplasmic chromatin in senescence

探索衰老过程中细胞质染色质的序列同一性

• 批准号: 10629244
• 负责人: Zhixun Dou
• 金额: $ 21万
• 依托单位: MASSACHUSETTS GENERAL HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-06-01 至 2025-03-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10629244
• 关键词: Address; Age; Aging; Automobile Driving; Autophagocytosis; Binding; Biochemical; Bulla; Cell Aging; Cell Cycle Arrest; Cell Nucleus; Cells; Chromatin; Chronic; Computer Analysis; Coupled; Cytoplasm; Cytoplasmic Organelle; Cytoplasmic Vesicles; Cytosol; DNA; DNA Binding; DNA purification; DNA sequencing; Development; Disease; Epigenetic Process; Exhibits; Formaldehyde; Gene Expression; Genes; Genetic; Genetic Transcription; Genome; Genomic DNA; Genomic Segment; Growth Factor; Image; Immune; Immunoprecipitation; Infection; Inflammation; Inflammatory; Inflammatory Response; Knowledge; Laboratories; Longevity; Lysosomes; Mediating; Membrane; Mus; Mutation; Natural Immunity; Nature; Nuclear Envelope; Outcome; Pathway interactions; Peptide Hydrolases; Pharmacologic Substance; Phenotype; Process; Research; Sampling; Signal Transduction; Source; Stimulator of Interferon Genes; Tissues; aged; antimicrobial; autocrine; chemokine; crosslink; cytokine; genetic information; healthspan; healthy aging; invention; microbial; next generation sequencing; novel strategies; novel therapeutics; paracrine; programs; protein complex; recruit; senescence; trafficking

PROJECT SUMMARY Cellular senescence is a stable form of cell cycle arrest associated with inflammatory responses. Senescent cells accumulate in aged and diseased tissues and are considered as one of the major sources contributing to chronic inflammation that is implicated in most, if not all, age-associated disorders. Consistent with this notion, genetic or pharmaceutical clearance of senescent cells extend lifespan and healthspan of mice. Senescent cells secret a large array of pro-inflammatory cytokines, chemokines, growth factors, and proteases, collectively referred to as senescence-associated secretory phenotype (SASP). The SASP program alters tissue microenvironment and recruits immune cells, ultimately leading to inflammation. Our group recently showed that senescent cells exhibit genomic DNA in the cytosol, which is interpreted by the cells as a “danger signal” by triggering the innate immunity cytosolic DNA sensing cGAS-STING pathway that promotes the SASP program of senescence. These findings have been independently reproduced by several laboratories, and collectively the cGAS-STING pathway is considered as a central mechanism for the SASP program. A major unaddressed question in senescence is the genetic origin of cytosolic genomic DNA. Our imaging results suggest that the cytosolic DNA is derived from fragments of chromatin, mediated by nucleus-to-cytoplasm trafficking, via nuclear membrane blebs that partition into the cytoplasm. But which parts of the genome are shuttled to the cytoplasm? What is the chromatin status of those regions? Does the genome lose genes? These questions require unbiased sequencing approaches to address. This application proposes two novel strategies to sequence cytoplasmic DNA in senescent cells. First, we aim to identify cGAS-associated cytosolic DNA in senescence, by performing cGAS DNA-immunoprecipitation. Second, we aim to biochemically fractionate the DNA from the cytoplasm of senescent cells. The DNA samples will be subjected to next-gen sequencing and computational analyses to explore the chromatin marks and gene expression status. These results will permit us to directly manipulate the genomic DNA to inquire the functional consequences of cells undergoing genomic DNA trafficking to the cytoplasm. This study will help the senescence field understand a critical mechanism underlying senescence- associated inflammation, and may reveal previously unknown knowledge of the genetic alterations of senescence and aging. This study has the potential to facilitate new approaches to target and inhibit chronic inflammation to promote healthy aging and to suppress age-associated diseases.

项目摘要 细胞感应是与炎症反应相关的细胞周期停滞形式。衰老 细胞积聚在老年和解剖组织中，被认为是有助于 大多数（如果不是全部）与年龄相关的疾病实施的慢性炎症。与这个概念一致， 感觉细胞的遗传或药物清除延伸了小鼠的寿命和健康状态。 衰老细胞向大量促炎细胞因子，趋化因子，生长因子和 蛋白酶，共同称为感应相关的秘书表型（SASP）。 SASP程序 改变组织微环境并募集免疫核管，最终导致炎症。我们的小组最近 表明感觉细胞暴露了细胞质中的基因组DNA，该细胞被细胞解释为“危险 信号”通过触发先天免疫性胞质DNA感应CGAS刺激途径，以促进SASP 感应程序。这些发现是由几个实验室独立复制的， 总体而言，CGAS-sting途径被视为SASP程序的中心机制。 感应中的一个主要未解决的问题是胞质基因组DNA的遗传起源。我们的想象力 结果表明，胞质DNA源自染色质的片段，由核核介导 通过核膜爆炸，分配到细胞质中。但是基因组的哪一部分是 穿上细胞质？这些区域的染色质状态是什么？基因组会失去基因吗？这些 问题需要无偏的测序方法来解决。该申请提出两种新型策略 在感觉细胞中序列细胞质DNA。首先，我们旨在确定与CGAS相关的胞质DNA 通过执行CGAS DNA免疫沉淀的感应。其次，我们的目标是将生化分类 来自感觉细胞细胞质的DNA。 DNA样品将进行下一代测序和 计算分析以探索染色质标记和基因表达状态。这些结果将允许 我们直接操纵基因组DNA来查询经历基因组细胞的功能后果 DNA运输到细胞质。 这项研究将有助于感应场了解感应感应的关键机制 相关的炎症，并可能揭示以前对有关遗传改变的知识 感应和衰老。这项研究有可能促进靶向和抑制慢性的新方法 炎症以促进健康的衰老并抑制与年龄相关的疾病。