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.

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 与环境因素和生活方式选择有关的人口，包括吸烟以及由 高脂肪和盐饮食。但是，受胸动脉瘤和解剖影响的患者中有20％ （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）有助于血管壁完整性的蛋白质和生长因子。虽然有许多基因 现在被确定为包含遗传形式的TAAD的因果突变，有75％的家庭中的因果基因 这种疾病尚未发现。我们最近确定了一个患有未知病因的TAAD的家庭。 通过整个基因组测序，我们确定了赖氨酸氧化酶（LOX）基因中的错义突变 （c.893t> g编码第298arg），与家族中的动脉瘤表型隔离。 Lox是一个 细胞外酶催化胺氧化反应，以进行关键的交联和成熟 血管壁中的弹性蛋白和胶原蛋白ECM蛋白。 为了了解LOX相关性动脉瘤疾病的基础机制，我们使用了 CRISPR/CAS9基因组编辑系统将人类突变引入小鼠（人类的M298R，M292R，M292R 在老鼠中）。携带M292R突变的小鼠中血管系统的表征证实了 突变确实确实导致主动脉瘤形成。 M292R突变纯合的动物死亡 由于主动脉瘤破裂，出生后的几个小时内。然而，动物杂合子是突变的 在3个月大时没有发生动脉瘤，而是在主动脉壁中碎片弹性纤维，这表明 突变动物在暴露有害刺激时可能会倾向于发展血管疾病。在 该建议，我们将利用此M292R鼠标模型来表征机制，导致变化 动脉壁并确定其他血管壁应力是否会诱导胸动脉瘤。 此外，我们将确定由于突变引起的改变LOX功能的机制 最终导致动脉瘤形成。将LOX鉴定为家族性TAAD的因果基因不仅会 允许我们在临床基因测试期间筛选LOX，但了解背后的机制 突变影响LOX酶功能将为潜在的治疗发育提供洞察力。