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

基本信息

批准号：
10452114
负责人：
Zhixun Dou
金额：
$ 25.2万
依托单位：
MASSACHUSETTS GENERAL HOSPITAL
依托单位国家：
美国
项目类别：
财政年份：
2022
资助国家：
美国
起止时间：
2022-06-01 至 2024-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10452114
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 sequencing Development Disease Epigenetic Process Exhibits Formaldehyde Gene Expression Genes Genetic 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 base chemokine crosslink cytokine genetic information healthspan healthy aging microbial next generation sequencing novel strategies novel therapeutics paracrine programs protein complex recruit senescence trafficking

项目摘要

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.

项目概要细胞衰老是与炎症反应相关的细胞周期停滞的一种稳定形式。细胞在衰老和患病的组织中积累，被认为是导致疾病的主要来源之一与大多数（如果不是全部）年龄相关疾病有关的慢性炎症，与这一概念一致。衰老细胞的遗传或药物清除可延长小鼠的寿命和健康寿命。衰老细胞分泌大量促炎细胞因子、趋化因子、生长因子和蛋白酶，统称为衰老相关分泌表型（SASP）。改变组织微环境并招募免疫细胞，最终导致我们小组最近的炎症。表明衰老细胞在细胞质中表现出基因组 DNA，这被细胞解释为“危险” 通过触发先天免疫细胞质 DNA 感应 cGAS-STING 通路来促进 SASP 这些发现已被多个实验室独立复制，并且总的来说，cGAS-STING 途径被认为是 SASP 计划的核心机制。衰老中一个尚未解决的主要问题是细胞质基因组 DNA 的遗传起源。结果表明，胞质 DNA 来源于染色质片段，由细胞核到细胞质介导通过划分到细胞质中的核膜泡进行运输，但是基因组的哪些部分是。穿梭到细胞质中的这些区域的染色质状态如何？该应用提出了两种新颖的策略。首先，我们的目标是鉴定衰老细胞中与 cGAS 相关的胞质 DNA。其次，我们的目标是通过进行 cGAS DNA 免疫沉淀来进行生化分级。来自衰老细胞细胞质的 DNA 样本将进行下一代测序和分析。这些结果将允许探索染色质标记和基因表达状态的计算分析。我们直接操作基因组DNA来探究细胞进行基因组测序的功能后果 DNA 运输到细胞质。这项研究将帮助衰老领域了解衰老背后的关键机制—— 相关的炎症，并可能揭示以前未知的基因改变知识这项研究有可能促进针对和抑制慢性衰老的新方法。炎症促进健康衰老并抑制与年龄相关的疾病。