Endothelial biomechanics in vascular aging

血管老化中的内皮生物力学

• 批准号: 10804883
• 负责人: Irena Levitan
• 金额: $ 32.78万
• 依托单位: UNIVERSITY OF ILLINOIS AT CHICAGO
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-07-01 至 2025-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10804883
• 关键词: Actins; Address; Age; Aging; Aorta; Appearance; Arteries; Atomic Force Microscopy; Binding; Binding Sites; Biomechanics; Blood Vessels; CD36 gene; Caveolins; Cell Nucleus; Cytoskeleton; DNA Damage; DNA Markers; Data; Deterioration; Dissociation; Docking; Dyslipidemias; Elasticity; Elderly; Endothelial Cells; Endothelium; Exposure to; Extracellular Matrix; Functional disorder; Gene Expression; Genetic; Genomic Instability; Goals; High Fat Diet; Image; In Vitro; Infiltration; Lipids; Mass Spectrum Analysis; Mediating; Membrane; Modeling; Molecular; Morphology; Mus; Nuclear; Nuclear Structure; Nuclear Translocation; Pathway interactions; Permeability; Play; Premature aging syndrome; Process; Proteins; Resolution; Risk; Role; Shapes; Signal Transduction; Site-Directed Mutagenesis; Stress Fibers; Testing; Tissues; Vascular Diseases; age related; aged; arterial stiffness; caveolin 1; comparative; confocal imaging; endothelial dysfunction; feeding; gain of function; immune cell infiltrate; in vivo; insight; laurdan; lipidomics; loss of function; machine learning algorithm; macromolecule; monocyte; monolayer; mouse model; multiphoton microscopy; novel; oxidized lipid; oxidized low density lipoprotein; prevent; receptor; scavenger receptor; simulation; transcription factor; transcriptome; transcriptome sequencing; transcriptomics; uptake; vascular inflammation

Endothelial biomechanics plays a key role in multiple endothelial functions. Our earlier studies discovered that oxidized lipids in vitro and dyslipidemia in vivo induce significant endothelial stiffening via CD36 scavenger receptor and incorporation of oxysterols. Most recently, we found that endothelial stiffening in aging aortas critically depends on CD36 and the caveolar protein, Caveolin-1 (Cav1). Our long term goal is to elucidate the mechanisms responsible for age-induced changes in endothelial biomechanics and to determine the contribution of these mechanisms to endothelial dysfunction. In the current proposal, we address three goals: In Aim 1, we focus on elucidating the mechanism of age-induced EC stiffening. First (1A), we will determine whether endothelial-specific deletions of CD36 and/or Cav1 prevent endothelial stiffening in moderately aged (10-12 months old) and advanced aged (20-24 months old) mice and whether expression/membrane localization of these proteins is altered by age. Then (1B), we will provide a comprehensive lipidomics analysis of changes in lipid composition in arterial tissues with age and identify specific lipid species that accumulate with age and induce endothelial stiffening. In Aim 2, we focus on age-related actin remodeling and disruption of endothelial barrier integrity. First (aim 2A), we will determine the roles of endothelial CD36 and Cav1 and CD36/Cav1-mediated uptake of oxidized lipids in age-related actin remodeling, junctional morphology, endothelial permeability to macromolecules, and infiltration of monocytes. In the second part of the aim (2B), we will investigate the molecular mechanisms by which oxidized lipids, particularly oxysterols, induce actin remodeling, focusing on a novel hypothesis that oxysterols compete with RhoA for binding to a RhoA inhibitory protein, GDI-1. In Aim 3, these studies are extended to investigate the impact of CD36/Cav1/oxysterol- dependent endothelial stiffening in inducing distortion of nuclear morphology, DNA damage and nuclear translocation of mechanosensitive transcription factors (3A) and explore the hypothesis that oxysterol-induced endothelial stiffening results in nuclei distortion by disruption of a peri-nuclear structure called the actin cap (3B). These studies are then extended to an exploratory sub-aim (3C) of comparative analysis of transcriptomic changes in aged endothelium in vivo and in endothelial cells exposed to oxidized lipids that induce endothelial stiffening. These goals are achieved using endothelial-specific loss of function (CD36 and Cav1) and gain of function (Cav1) genetic mouse models. A combination of Atomic Force Microscopy, lipid mass-spectrometry, high resolution confocal imaging analyzed by machine-learning algorithms and other state- of-the-art experimental approaches. Taken together, these studies are expected to provide significant new insights into our understanding of the mechanisms responsible for endothelial stiffening in aging vasculature and the role of lipid-induced endothelial stiffening in age-related barrier disruption and nuclei abnormalities.

内皮生物力学在多个内皮功能中起关键作用。我们较早的研究发现 体外氧化的脂质和血脂异常在体内诱导明显的内皮僵硬通过CD36清道夫 受体和氧化酚的掺入。最近，我们发现衰老主动脉的内皮僵硬 关键取决于CD36和小窝蛋白Caveolin-1（Cav1）。我们的长期目标是阐明 负责年龄引起的内皮生物力学变化的机制，并确定 这些机制对内皮功能障碍的贡献。在当前的建议中，我们解决了三个目标： 在AIM 1中，我们专注于阐明年龄引起的EC僵硬的机制。首先（1a），我们将确定 CD36和/或CAV1的内皮特异性缺失是否可以防止内皮僵硬 （10-12个月大）和高年龄（20-24个月大）小鼠，以及表达/膜是否 这些蛋白质的定位会随着年龄的增长而改变。然后（1b），我们将提供全面的脂质分析分析 随着年龄的增长而识别累积的特定脂质物种的动脉组织中脂质组成的变化 随着年龄的增长和诱导内皮僵硬。在AIM 2中，我们专注于与年龄相关的肌动蛋白的重塑和破坏 内皮屏障完整性。首先（AIM 2A），我们将确定内皮CD36和CAV1的作用以及 CD36/CAV1介导的氧化脂质在与年龄相关的肌动蛋白重塑，连接形态的摄取， 对大分子的内皮渗透性和单核细胞的浸润。在目标的第二部分（2b）， 我们将研究氧化脂质，尤其是氧甲醇的分子机制，诱导肌动蛋白 重塑，重点是一种新的假设，即氧甲甲醇与RhoA竞争与RhoA抑制性的结合 蛋白质，GDI-1。在AIM 3中，对这些研究进行了扩展，以研究CD36/CAV1/氧甲醇的影响 依赖的内皮僵硬在诱导核形态，DNA损伤和核的变形时 机械敏感转录因子（3A）的易位，并探讨了氧蛋白酶诱导的假设 内皮变化会导致核畸变，通过破坏核周结构，称为肌动蛋白帽 （3b）。然后将这些研究扩展到比较分析的探索性子AIM（3C） 体内老化内皮的转录组变化和暴露于氧化脂质的内皮细胞中 诱导内皮僵硬。这些目标是使用特定于内皮的功能丧失来实现的（CD36和 CAV1）和功能增益（CAV1）遗传小鼠模型。原子力显微镜，脂质的组合 通过机器学习算法和其他状态 - 艺术实验方法。综上所述，这些研究有望提供重要的新 洞悉我们对衰老脉管系统内皮僵硬的机制的理解 以及脂质引起的内皮僵硬在与年龄相关的屏障破坏和核异常中的作用。