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

• 批准号: 10576391
• 负责人: Yuk Yuen Lan
• 金额: $ 20.46万
• 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: 2022-03-01 至 2024-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10576391
• 关键词: Abate; Acceleration; 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; Ploidies; Polyarthritides; Premature aging syndrome; Production; Progeria; Property; Retrotransposon; Risk; Role; Signal Transduction; Sterility; Stimulator of Interferon Genes; System; Tissues; cell growth; clinically relevant; ds-DNA; endonuclease; extranuclear DNA; immune activation; immunogenic; immunoregulation; improved; insight; member; novel; novel strategies; novel therapeutic intervention; nuclease; overexpression; patient engagement; response; senescence; sensor; systemic inflammatory response; theories; transcriptomics

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.

项目摘要 无菌注射暴露在与衰老有关的疾病中，包括心脏病，癌症， 糖尿病和认知能力下降。这种高炎症通常显示出改变的免疫 响应完成I型干扰响应和下游感应相关的响应 秘书表型（SASP）。诱发这种慢性低度炎症的内在因素 不太了解。在研究小鼠自身免疫性多关节炎的倡议时 溶酶体核酸内切酶Dnase2a，我们发现了一种细胞自主途径 受损的核DNA被贩运到细胞质，在那里被固有的胞质识别 DNA感应CGAS刺轴，引发炎症级联反应。在健康细胞中，核细胞 通过自噬去除了DNASE2A的溶酶体降解，在细胞质中发现的DNA， 它降解了双链DNA（dsDNA） - DNA传感器CGA的配体。持续的 有了这个观念，即当误差时受损或无法弥补的核DNA是免疫力的触发因素 局部和积累在细胞质中，复制中核外DNA的载荷升高 来自共济失调（AT）和促进性（HGP）患者的感觉细胞和细胞与相同的DNA相同 感知导致持续炎症的途径。因此，控制固有的DNA负载是 对于避免无菌注射至关重要。虽然核能可以清除DNA，但未知的DNA输出因子 可能有助于DNA出口到细胞质。通过瞄准策划的一组潜在核和DNA 导出因素，我们建议在单细胞中识别未知的固有DNA控制因子 通过使用免疫荧光测定DSDNA含量，基于CRIS敲除光学屏幕。 命中率将以其DNA导出或降解功能进行验证，并因其参与而排名 在CGA的下游感应和刺激激活中。选定的热门单曲以及 DNase2a，将评估其在抑制注射和SASP中的能力 感觉细胞以及AT和HGPS患者细胞。在DNASE2A敲除小鼠中，我们将调查 组织中的免疫细胞表型了解全身性的机制 感觉病理学。炎症中新决定者的识别和表征 感应将为DNA介导的免疫力的基本生物学增添新的见解并开放 提出调节炎症以使衰老相关病理的新型策略，包括 干扰素病和椎板病，自身免疫和癌症。