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.

内皮生物力学在多种内皮功能中发挥着关键作用。我们早期的研究发现 体外氧化脂质和体内血脂异常通过 CD36 清除剂诱导显着的内皮硬化 受体和氧甾醇的掺入。最近，我们发现老化主动脉的内皮硬化 关键取决于 CD36 和小凹蛋白 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。在当前的提案中，我们实现了三个目标： 在目标 1 中，我们重点阐明年龄引起的 EC 硬化的机制。首先 (1A)，我们将确定 CD36 和/或 Cav1 的内皮特异性缺失是否可以预防中年老年人的内皮硬化 （10-12个月大）和高龄（20-24个月大）小鼠以及是否表达/膜 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组学分析 动脉组织中脂质成分随年龄的变化，并确定积累的特定脂质种类 随着年龄的增长并引起内皮硬化。在目标 2 中，我们关注与年龄相关的肌动蛋白重塑和破坏 内皮屏障完整性。首先（目标 2A），我们将确定内皮 CD36 和 Cav1 的作用以及 CD36/Cav1 介导的氧化脂质摄取在年龄相关肌动蛋白重塑、连接形态、 内皮对大分子的通透性和单核细胞的浸润。在目标的第二部分（2B）中， 我们将研究氧化脂质（特别是氧甾醇）诱导肌动蛋白的分子机制 重塑，重点关注氧甾醇与 RhoA 竞争结合 RhoA 抑制剂的新假设 蛋白质，GDI-1。在目标 3 中，这些研究扩展到调查 CD36/Cav1/氧固醇的影响 依赖性内皮硬化诱导核形态扭曲、DNA 损伤和核 机械敏感转录因子 (3A) 的易位并探索氧甾醇诱导的假设 内皮硬化会破坏称为肌动蛋白帽的核周结构，导致细胞核变形 （3B）。然后，这些研究扩展到探索性子目标（3C）的比较分析 体内老化内皮细胞和暴露于氧化脂质的内皮细胞的转录组变化 引起内皮硬化。这些目标是通过内皮特异性功能丧失（CD36 和 Cav1) 和功能获得 (Cav1) 遗传小鼠模型。原子力显微镜、脂质的组合 质谱分析、通过机器学习算法和其他状态分析的高分辨率共焦成像 最先进的实验方法。总而言之，这些研究预计将提供重要的新成果 深入了解我们对老化脉管系统内皮硬化机制的理解 以及脂质诱导的内皮硬化在与年龄相关的屏障破坏和细胞核异常中的作用。