Lysyl Oxidase Mutations in Cardiovascular Disease

心血管疾病中的赖氨酰氧化酶突变

基本信息

批准号：
9533187
负责人：
Vivian Lee-Kim
金额：
$ 0.3万
依托单位：
WASHINGTON UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2017
资助国家：
美国
起止时间：
2017-03-01 至 2018-04-15
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9533187
关键词：
Address Affect Age-Months Amines Aneurysm Animals Aorta Aortic Aneurysm Birth Blood Vessels CRISPR/Cas technology Cardiovascular Diseases Cause of Death Collagen Development Diet Disease Disease Progression Dissection Elastic Fiber Elastin Environmental Risk Factor Enzymes Etiology Event Excision Extracellular Matrix Proteins Extracellular Space Family Fatty acid glycerol esters Genes Genetic Genetic screening method Growth Factor Heritability Hour Human Hypertension Individual Inherited LOX gene Lead Life Style Medical Genetics Missense Mutation Morbidity - disease rate Mus Mutation Obesity Older Population Penetrance Phenotype Process Protein-Lysine 6-Oxidase Pulmonary Valve Insufficiency Reaction Ruptured Aneurysm Ruptured Aortic Aneurysms Sagittaria Smoking Sodium Chloride Stimulus Stress System Thick Thoracic Aortic Aneurysm Time United States Vascular Diseases Vascular System ascending aorta crosslink disease-causing mutation enzyme activity extracellular genome editing genome sequencing hemodynamics human disease insight mature animal mortality mouse model mutant mutant mouse model oxidation protein function therapeutic development whole genome

项目摘要

ABSTRACT Cardiovascular diseases including aortic aneurysms are generally considered disease of the older population related to environmental factors and life style choices including smoking, and obesity caused by high fat and salt diets. However, 20 percent of individuals affected by thoracic aortic aneurysm and dissections (TAAD) have a heritable form, commonly attributed to mutations in genes that encode for extracellular matrix (ECM) proteins and growth factors that contribute to vascular wall integrity. While there are a number of genes now identified as containing causal mutations for inherited forms of TAAD, causal genes in 75% of families with this disease have not been discovered. We recently identified a family with TAAD with unknown etiology. Through whole genome sequencing, we identified a missense mutation in the lysyl oxidase (LOX) gene (c.893T>G encoding p. Met298Arg) that segregated with the aneurysm phenotype in the family. LOX is an extracellular enzyme that catalyzes the amine oxidation reaction for critical crosslinking and maturation of elastin and collagen- key ECM proteins in the vessel wall. To understand the mechanism underlying Lox-associated aneurysmal disease, we used the CRISPR/Cas9 genome editing system to introduce the human mutation into mice (M298R in humans, M292R in mice). Characterization of the vascular system in mice carrying the M292R mutation confirmed that the mutation does indeed lead to aortic aneurysm formation. Animals homozygous for the M292R mutation died within a few hours of birth due to ruptured aortic aneurysm. Animals heterozygous for the mutation, however, did not develop aneurysms at 3 months of age, but had fragmented elastic fibers in the aorta wall, suggesting that the mutant animals may be predisposed to develop vascular disease when exposed of injurious stimuli. In this proposal, we will utilize this M292R mouse model to characterize mechanisms leading to changes in the arterial wall and determine whether additional vascular wall stress will induce thoracic aortic aneurysms. Furthermore, we will identify mechanisms underlying altered LOX function caused by the mutation that ultimately leads to aneurysm formation. Identification of Lox as a causal gene for familial TAAD will not only allow us to screen for Lox during clinical genetic testing, but understanding the mechanism behind how the mutation affects Lox enzyme function will provide insight into potential therapeutic development.

抽象的包括主动脉瘤在内的心血管疾病通常被认为是老年人的疾病人口与环境因素和生活方式选择有关，包括吸烟和肥胖引起的高脂肪和高盐饮食。然而，20% 的人受到胸主动脉瘤和夹层的影响（TAAD）具有可遗传的形式，通常归因于编码细胞外基质的基因突变 (ECM) 蛋白质和生长因子有助于血管壁的完整性。虽然有很多基因现已确定含有 TAAD 遗传形式的因果突变，75% 的 TAAD 家族中有因果基因这种疾病尚未被发现。我们最近发现了一个病因不明的 TAAD 家族。通过全基因组测序，我们发现了赖氨酰氧化酶（LOX）基因的错义突变（c.893T>G 编码 p.Met298Arg）与家族中的动脉瘤表型分离。液氧是一种胞外酶，催化胺氧化反应，以实现关键的交联和成熟弹性蛋白和胶原蛋白——血管壁中的关键 ECM 蛋白。为了了解 Lox 相关动脉瘤疾病的机制，我们使用 CRISPR/Cas9基因组编辑系统将人类突变引入小鼠（人类中的M298R，M292R 在小鼠中）。对携带 M292R 突变的小鼠血管系统的表征证实，突变确实会导致主动脉瘤的形成。 M292R 突变纯合动物死亡出生后数小时内因主动脉瘤破裂。然而，突变杂合的动物， 3个月大时并未出现动脉瘤，但主动脉壁上有断裂的弹力纤维，这表明突变动物在受到伤害性刺激时可能容易患上血管疾病。在在这个提案中，我们将利用这个 M292R 小鼠模型来表征导致变化的机制动脉壁并确定额外的血管壁应力是否会诱发胸主动脉瘤。此外，我们将确定由以下突变引起的 LOX 功能改变的机制：最终导致动脉瘤的形成。鉴定 Lox 作为家族性 TAAD 的致病基因不仅将让我们能够在临床基因检测期间筛查 Lox，但了解其背后的机制突变影响 Lox 酶功能将为潜在的治疗开发提供见解。