Cellular Models of a Monogenic Small Vessel Disease of the Brain

脑单基因小血管疾病的细胞模型

• 批准号: 10307638
• 负责人: DENNIS EMIL HOURCADE
• 金额: $ 19.69万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-12-01 至 2023-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10307638
• 关键词: 3' Untranslated Regions; Abate; Address; Age; Alleles; Alzheimer' s disease pathology; Attenuated; Basement membrane; Biological Markers; Biological Products; Blood Vessels; Brain; Brain Diseases; Brain Pathology; Cell Aging; Cell Cycle; Cell Cycle Regulation; Cell Death; Cell Nucleus; Cell model; Cells; Cerebrum; Cessation of life; Chemical Agents; Clinical; Code; Complex; Cytosol; DNA; DNA Damage; DNA Maintenance; DNA Repair; DNA biosynthesis; DNA lesion; Defect; Dementia; Deoxyribonucleases; Detection; Development; Disease; Endoplasmic Reticulum; Endothelial Cells; Event; Exonuclease; Fibrinoid necrosis; Frameshift Mutation; Functional disorder; Genotype; Goals; Injury; Innate Immune Response; Investigation; Kidney; Leukoencephalopathy; Liver; Membrane; Methods; Microvascular Dysfunction; Molecular; Monitor; Mutation; Myeloid Cells; Neurologic; Onset of illness; Organ; Pathologic; Pathway interactions; Patients; Play; Positioning Attribute; Premature aging syndrome; Prevention; Process; Proteins; RNA Interference; Radiation necrosis; Rare Diseases; Retina; Risk Factors; Role; SHPS-1 protein; Secondary to; Signal Transduction; Signaling Protein; Skin; Stenosis; System; TREX1 gene; TREX1 protein; Therapeutic; Three Prime Repair Exonuclease 1; Translations; Ursidae Family; Vascular Diseases; Visual; Western Blotting; disorder prevention; exodeoxyribonuclease; gain of function; middle age; mortality; mutant; novel therapeutic intervention; rare genetic disorder; repaired; response; spleen exonuclease; vascular cognitive impairment and dementia; white matter

Project Summary VCID (Vascular contributions to cognitive impairment and dementia) is increasingly recognized as both a primary cause of dementia and as a secondary contributor to dementia, as in the setting of Alzheimer’s pathology. VCID most commonly progresses from accumulated injury due to small vessel disease of the brain (SVD). While several risk factors are associated with SVD, the mechanisms that drive its initiation and progression have not been well characterized. Retinal Vasculopathy with Cerebral Leukoencephalopathy and Systemic Manifestations (RVCL-S) is a rare monogenic late onset condition that bears striking clinical and pathological similarities to small vessel disease of the brain. Our goal is to facilitate the development of new methods for the prevention and treatment of sporadic SVD through an investigation of RVCL-S. RVCL-S is caused by dominant mutations in the autosomal gene TREX1 which encodes the major intracellular 3’ DNA exonuclease. TREX1 protein harbors two major functional domains: the amino-terminal domain is the exonuclease while the carboxy-terminal domain positions the protein in the endoplasmic reticulum (ER) membrane, extending the DNAse domain into the cytosol where it plays a critical role in dampening the innate immune response to cytosolic self-DNA. RVCL-S is caused by fully penetrant frameshift mutations in TREX1 gene, each producing a protein that carries a functional exonuclease domain but lacks the domain that anchors the complete protein to the ER membrane resulting in atypical localization of TREX1 exonuclease throughout the cytosol and the nucleus. Importantly, mutations that truncate TREX1 within the exonuclease coding region, resulting in proteins lacking both DNase activity and the ER membrane tether, are not pathogenic in the heterozygous state, suggesting that RVCL-S is caused by a toxic gain-of-function of the untethered exonuclease. We propose that aberrant activity of TREX1 exonuclease in the cell nucleus interferes with DNA replication/repair as well as the activity of closely coordinated cell cycle regulatory signaling proteins. Our long- term objectives are to identify the critical detrimental effects of the mutant exonuclease and to develop strategies to abate these effects. To that end we propose the following specific aims: 1. Examine the effects of the RVCL-S genotype on the DNA damage response and cell cycle regulation. 2. Employ RNA interference to suppress expression of the RVCL-S associated TREX1 frameshift mutant. Impact: Successful completion of this study will provide 1) strategies for disease prevention; 2) biomarkers for disease monitoring; and 3) novel therapeutic approaches that will be applicable to RVCL-S and very likely applicable to sporadic SVD.

项目概要 VCID（血管对认知障碍和痴呆症的影响）越来越被认为是 是痴呆症的主要原因，也是痴呆症的次要因素，如阿尔茨海默病 病理。 VCID 最常见的进展是由于大脑小血管疾病引起的累积损伤 （奇异值分解）。虽然有几个风险因素与 SVD 相关，但驱动其发生和发生的机制 进展尚未得到很好的表征。视网膜血管病变伴脑白质脑病和 全身表现（RVCL-S）是一种罕见的单基因迟发性疾病，具有惊人的临床和 病理学上与大脑小血管疾病相似。我们的目标是促进新产品的开发 通过研究 RVCL-S 来预防和治疗散发性 SVD 的方法。 RVCL-S 是由常染色体基因 TREX1 的显性突变引起的，该基因编码主要的 细胞内 3' DNA 核酸外切酶。 TREX1 蛋白具有两个主要功能域：氨基末端 结构域是核酸外切酶，而羧基末端结构域将蛋白质定位在内质网中 (ER) 膜，将 DNAse 结构域延伸到胞质溶胶中，在抑制 对细胞质自身 DNA 的先天免疫反应。 RVCL-S 是由完全渗透性移码突变引起的 TREX1 基因，每个基因产生一种携带功能性核酸外切酶结构域但缺乏功能性结构域的蛋白质 将完整蛋白质锚定到内质网膜上，导致 TREX1 核酸外切酶非典型定位 遍及细胞质和细胞核。重要的是，在核酸外切酶内截断 TREX1 的突变 编码区，导致蛋白质缺乏 DNase 活性和 ER 膜系链，不具有致病性 处于杂合状态，表明 RVCL-S 是由不受束缚的毒性功能获得引起的 核酸外切酶。我们认为细胞核中 TREX1 核酸外切酶的异常活性会干扰 DNA 复制/修复以及密切协调的细胞周期调节信号蛋白的活性。我们的长期 术语目标是确定突变核酸外切酶的关键有害影响并制定策略 以减轻这些影响。为此，我们提出以下具体目标： 1. 检查 RVCL-S 基因型对 DNA 损伤反应和细胞周期调节的影响。 2.采用RNA干扰来抑制RVCL-S相关TREX1移码突变体的表达。 影响：成功完成本研究将提供 1) 疾病预防策略； 2) 生物标志物 疾病监测； 3) 新的治疗方法将适用于 RVCL-S，并且很可能 适用于散发性SVD。