Lysyl Oxidase Mutations in Cardiovascular Disease

心血管疾病中的赖氨酰氧化酶突变

• 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
• 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

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.

摘要 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。 与环境因素和生活方式选择有关的人口，包括吸烟和由以下原因引起的肥胖 高脂肪和高盐饮食。然而，20%的受胸主动脉瘤和夹层影响的人 (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)有助于维管壁完整性的蛋白质和生长因子。虽然有许多基因 现在被确认为包含遗传性TAAD的因果突变，75%的患有TAAD的家庭的病因基因 这种病还没有被发现。我们最近发现了一个病因不明的TAAD家系。 通过全基因组测序，我们发现了赖氨酰氧化酶(LOX)基因的一个错义突变 (C.893T&gt；G编码P.Met298Arg)，与该家族中的动脉瘤表型分离。鲑鱼是一种 催化胺氧化反应的胞外酶，用于临界交联和成熟 弹性蛋白和胶原--血管壁上关键的细胞外基质蛋白。 为了了解Lox相关动脉瘤疾病的机制，我们使用了 CRISPR/Cas9基因组编辑系统将人类突变导入小鼠(人类的M298R，M292R 在小鼠身上)。携带M292R突变的小鼠的血管系统特征证实 突变确实会导致主动脉瘤的形成。M292R突变纯合子动物死亡 出生后几小时内因主动脉瘤破裂而死亡。然而，突变为杂合子的动物， 在3个月龄时没有出现动脉瘤，但在主动脉壁中有碎裂的弹性纤维，这表明 当这些突变动物暴露在有害刺激下时，可能容易患上血管疾病。在……里面 在这个提案中，我们将利用这个M292R小鼠模型来表征导致细胞周期改变的机制 并确定额外的血管壁应力是否会导致胸主动脉瘤。 此外，我们将确定由突变引起的LOX功能改变的潜在机制 最终导致动脉瘤的形成。确定LOX是家族性TAAD的致病基因不仅将 允许我们在临床基因测试期间筛查LOX，但了解背后的机制是如何 突变影响Lox酶功能将为潜在的治疗开发提供洞察。