Exploring Determinants of Intrinsic DNA Load Towards Inflammaging

探索导致炎症的内在 DNA 负荷的决定因素

基本信息

批准号：
10373598
负责人：
Yuk Yuen Lan
金额：
$ 24.66万
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：
2022-03-01 至 2024-02-29
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10373598
关键词：
Abate Aging Algorithms Ataxia Ataxia Telangiectasia Autoimmune Autoimmunity Automobile Driving Autophagocytosis Biological Biological Assay Biological Process Biology Cell Aging Cell Nucleus Cells Cellular Morphology Chromatin Chronic Clustered Regularly Interspaced Short Palindromic Repeats Cyclic GMP Cytosol DNA DNA Damage DNA Virus Infections Diabetes Mellitus Disease Exhibits Family Foundations Future Genomic Instability Heart Diseases Homeostasis Human Immune Immune response Immunity Immunofluorescence Immunologic Impaired cognition Infection Inflammaging Inflammation Inflammatory Interferon Type I Interferons Intrinsic factor Knock-out Knockout Mice Ligands Malignant Neoplasms Mediating Mitochondrial DNA Modeling Mus Nuclear Optics Pathologic Pathology Pathway interactions Patients Pattern Phenotype Play Ploidies Polyarthritides Premature aging syndrome Production Progeria Property Retrotransposon Risk Role Signal Transduction Sterility Stimulator of Interferon Genes System Tissues base cell growth clinically relevant ds-DNA endonuclease extranuclear DNA immune activation immunogenic improved insight member novel novel strategies novel therapeutic intervention nuclease overexpression response senescence sensor systemic inflammatory response theories transcriptomics

项目摘要

PROJECT SUMMARY Sterile inflammation is exhibited in aging‐related conditions, including heart disease, cancer, diabetes, and cognitive decline. Such hyperinflammation typically displays an altered immune response comprising a type I interferon response and downstream senescence-associated secretory phenotype (SASP). The intrinsic factors that induce this chronic low-grade inflammation are not well understood. In studying the initiation of autoimmune polyarthritis in mice lacking the lysosomal endonuclease Dnase2a, we discovered a cell‐autonomous pathway through which damaged nuclear DNA is trafficked to the cytosol where it is recognized by the innate cytosolic DNA sensing cGAS-STING axis, triggering an inflammatory cascade. In healthy cells, nuclear DNA found in the cytosol is removed via autophagy for lysosomal degradation by DNASE2A, which degrades double-stranded DNA (dsDNA)—ligand for the DNA sensor cGAS. Consistent with this notion that damaged or irreparable nuclear DNA is a trigger of immunity when mis- localized and accumulated in the cytosol, elevated loads of extranuclear DNA in replicative senescent cells and cells from ataxia (AT) and progeria (HGPS) patients engage the same DNA sensing pathway leading to persistent inflammation. Controlling the intrinsic DNA load is thus critical to avoid sterile inflammation. While nucleases can clear DNA, unknown DNA export factors may facilitate DNA exit to the cytosol. By targeting curated sets of potential nucleases and DNA export factors, we propose to identify unknown intrinsic DNA controlling factors in a single-cell based CRISPR knockout optical screen by assaying dsDNA content using immunofluorescence. Hits will be validated for their DNA export or degradative function and ranked for their involvement in senescence and STING activation downstream of cGAS. Selected tops hits, along with DNASE2A, will be evaluated for their capacity in suppressing inflammation and SASP in senescent cells and AT and HGPS patient cells. In Dnase2a knockout mice, we will investigate immune cell phenotype in tissues to understand the mechanisms underlying the systemic senescent pathology. The identification and characterization of new determinants in inflammation and senescence will add new insights to the basic biology of DNA-mediated immunity and open up novel strategies in modulating inflammation to benefit aging-associated pathologies, including interferonopathy and laminopathy, autoimmunity and cancer.

项目概要无菌性炎症表现在与衰老相关的疾病中，包括心脏病、癌症、糖尿病和认知能力下降通常表现出免疫。反应包括 I 型干扰素反应和下游衰老相关反应分泌表型（SASP）是诱发这种慢性低度炎症的内在因素。在研究缺乏该基因的小鼠中自身免疫性多关节炎的发生方面尚不清楚。溶酶体核酸内切酶 Dnase2a，我们发现了一条细胞自主途径，通过该途径受损的核 DNA 被运输至细胞质，并被先天细胞质识别。 DNA 感应 cGAS-STING 轴，在健康细胞核中引发炎症级联反应。细胞质中发现的 DNA 通过 DNASE2A 的溶酶体降解作用通过自噬去除，它可以降解双链 DNA (dsDNA)——DNA 传感器 cGAS 的配体。根据这一观点，受损或不可修复的核 DNA 在错误的情况下会触发免疫。定位并积累在细胞质中，复制过程中核外 DNA 的负载量增加衰老细胞和共济失调 (AT) 和早衰 (HGPS) 患者的细胞具有相同的 DNA 因此，控制内在 DNA 负荷是导致持续炎症的传感途径。虽然核酸酶可以清除 DNA，但未知的 DNA 输出因子对于避免无菌性炎症至关重要。通过靶向潜在的核酸酶和 DNA 组，可以促进 DNA 退出细胞质。输出因素，我们建议识别单细胞中未知的内在 DNA 控制因素通过使用免疫荧光测定 dsDNA 含量进行基于 CRISPR 敲除光学筛选。将验证命中的 DNA 输出或降解功能，并根据其参与程度进行排名衰老和 cGAS 下游的 STING 激活，以及选定的顶部命中。 DNASE2A，将评估其抑制炎症和 SASP 的能力我们将在 Dnase2a 敲除小鼠中研究衰老细胞以及 AT 和 HGPS 患者细胞。组织中的免疫细胞表型，以了解系统性免疫细胞的潜在机制炎症新决定因素的鉴定和表征。衰老将为 DNA 介导的免疫的基础生物学增添新的见解，并开放制定调节炎症的新策略，以有益于与衰老相关的病理，包括干扰素病和核纤层病、自身免疫和癌症。