Lysyl Oxidase Like 2: A Novel Target in Aging Associated Vascular Stiffening

赖氨酰氧化酶样 2：衰老相关血管硬化的新靶点

• 批准号: 10391440
• 负责人: Lakshmi Santhanam
• 金额: $ 40.65万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-04-01 至 2024-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10391440
• 关键词: Age; Aging; Animal Model; Architecture; Behavior; Biochemical; Biochemistry; Biological Availability; Biology; Blood Vessels; Cardiovascular system; Caring; Cause of Death; Cells; Cellular Assay; Clinical; Clinical Management; Collagen; Data; Deposition; Deterioration; Development; Disease; Elderly; Environment; Essential Hypertension; Etiology; Event; Extracellular Matrix; Extracellular Matrix Proteins; Factor Xa; Fibrosis; Financial Hardship; Foundations; Functional disorder; Genetic; Goals; Grant; Hypertension; In Vitro; Interdisciplinary Study; Interruption; Investigation; Knock-out; Knowledge; LOX gene; LOXL2 gene; Laboratories; Lead; Life Style Modification; Measures; Mediating; Mission; Molecular; Molecular Biology; Morbidity - disease rate; Mus; Myography; National Heart, Lung, and Blood Institute; Nitric Oxide; Pharmacology; Physiologic pulse; Population; Pre-Clinical Model; Protein Biochemistry; Proteins; Proteolytic Processing; Proteomics; Public Health; Reagent; Regulation; Role; SRCR proteins; Scaffolding Protein; Scavenger Receptor Cysteine-Rich Domain; Scheme; Smooth Muscle Myocytes; Source; Substrate Specificity; Sum; Syncope; Tamoxifen; Testing; Therapeutic; Translating; Vascular Smooth Muscle; Work; Youth; age related; aging population; amine oxidase; base; crosslink; demographics; effective therapy; experimental study; falls; in vivo; innovation; insight; middle age; mortality; mouse model; multidisciplinary; novel; novel therapeutics; pressure; prevent; protein protein interaction; scaffold; targeted agent; targeted treatment

Project summary: Increased central vascular stiffness in aging is an independent predictor of major adverse cardiovascular events and the leading cause of morbidity and mortality in the elderly. While mechanisms of vascular stiffening are emerging, targeted therapies are not yet available. Vascular stiffening and its sequelae remain clinically challenging to manage and currently, care relies on lifestyle modifications and pharmacologic agents targeting essential hypertension despite the distinct etiology and cellular molecular mechanisms, leading to syncope and falls in the elderly. and with the shift of population demographics towards the elderly, the clinical, societal, and financial burden of vascular stiffening has grown. Therefore, there is an urgent need to identify and characterize potential targets for clinical management of vascular stiffening and mitigate its sequelae. Using an unbiased proteomic screen, we have identified lysyl oxidase like 2 (LOXL2) as a novel protein that mediates vascular stiffening. Our hypothesis, strongly supported by preliminary data, is that LOXL2 regulates matrix composition, deposition, and architecture, modulates vascular smooth muscle cell (VSMC) micromechanics and contractility, and contributes to aging associated increase in vascular stiffness in mice. In this grant, we propose to examine the mechanisms of LOXL2-mediated vascular stiffening in aging in a hierarchical fashion from cells to mouse models of aging. We have generated novel reagents, mouse models, and assembled a strong, multidisciplinary research team to successfully execute the proposed work. In Aim 1, we will determine the mechanism of LOXL2 regulation by nitric oxide and proteolytic processing by Factor Xa in VSMCs. These aspects of LOXL2 regulation in cells and vasculature are not yet known. In Aim 2, we postulate that the scavenger receptor cysteine rich (SRCR) domains and amine oxidase (LOX) domains present in LOXL2 have distinct functions that contribute uniquely to vascular stiffening. We will 1) define the mechanisms of ECM remodeling by LOXL2 with specific emphasis on its putative scaffolding function and 2) determine how LOXL2 modulates VSMC micromechanics, cytoskeletal dynamics, and behavior/function. In Aim 3, we will determine if targeting LOXL2 mitigates age-associated vascular stiffening in mouse models. Using a combination of genetic (tamoxifen inducible global, VSMC-specific, and EC-specific LOXL2-/- mice), and pharmacologic (PAT-1251) approaches to target LOXL2, we will identify 1) the cellular source of LOXL2 in the aging vessel, 2) investigate if LOXL2 targeting can halt or reverse vascular stiffening in aging, and 3) identify whether VSMC stiffening or ECM deposition is the primary mechanism by which LOXL2 acts in the aging vessel. In sum, these studies will advance our knowledge of LOXL2 protein biochemistry and biology, establish the mechanisms by which LOXL2 is regulated in the vasculature, determine the mechanisms by which LOXL2 drives age-associated vascular stiffening, and lay the scientific foundation for the discovery and development of novel and effective therapies for the clinical management of vascular stiffening.

项目概要： 衰老过程中中央血管僵硬度的增加是主要心血管不良事件的独立预测因素 事件以及老年人发病和死亡的主要原因。血管硬化的机制 新兴的疾病，目前还没有针对性的治疗方法。血管僵硬及其后遗症在临床上仍然存在 管理具有挑战性，目前，护理依赖于生活方式的改变和靶向药物 原发性高血压尽管病因学和细胞分子机制不同，但仍会导致晕厥和 跌倒在老年人身上。随着人口结构向老年人的转变，临床、社会和 血管硬化的经济负担增加了。因此，迫切需要识别和 描述血管硬化临床治疗的潜在目标并减轻其后遗症。 通过无偏蛋白质组筛选，我们鉴定出赖氨酰氧化酶样 2 (LOXL2) 是一种新型蛋白质 介导血管硬化。我们的假设是 LOXL2，得到了初步数据的有力支持。 调节基质组成、沉积和结构，调节血管平滑肌细胞 (VSMC) 微力学和收缩性，并导致小鼠衰老相关的血管硬度增加。在 这笔资助，我们建议在衰老过程中研究 LOXL2 介导的血管硬化的机制 从细胞到小鼠衰老模型的分层时尚。我们已经生成了新的试剂、小鼠模型、 并组建了一支强大的多学科研究团队来成功执行拟议的工作。 在目标 1 中，我们将确定一氧化氮和蛋白水解加工调节 LOXL2 的机制 通过 VSMC 中的 Xa 因子。 LOXL2 在细胞和脉管系统中调节的这些方面尚不清楚。瞄准 2、我们假设清道夫受体富含半胱氨酸（SRCR）结构域和胺氧化酶（LOX）结构域 LOXL2 中存在的功能具有独特的功能，对血管硬化有独特的贡献。我们将 1) 定义 LOXL2 的 ECM 重塑机制，特别强调其假定的支架功能和 2) 确定 LOXL2 如何调节 VSMC 微力学、细胞骨架动力学和行为/功能。在 目标 3，我们将确定靶向 LOXL2 是否可以减轻小鼠模型中与年龄相关的血管硬化。 使用遗传组合（他莫昔芬诱导型全局小鼠、VSMC 特异性小鼠和 EC 特异性 LOXL2-/- 小鼠）， 和药理学 (PAT-1251) 方法来靶向 LOXL2，我们将确定 1) LOXL2 的细胞来源 老化血管，2) 研究 LOXL2 靶向是否可以阻止或逆转老化血管硬化，以及 3) 确定 VSMC 硬化或 ECM 沉积是否是 LOXL2 在 老化的容器。总之，这些研究将增进我们对 LOXL2 蛋白生物化学和生物学的了解， 建立 LOXL2 在脉管系统中的调节机制，确定机制 LOXL2 驱动与年龄相关的血管硬化，并为这一发现和 开发用于血管硬化临床治疗的新颖有效的疗法。