Impact of dyslipidemia on endothelial biomechanics

血脂异常对内皮生物力学的影响

• 批准号: 7877943
• 负责人: Irena Levitan
• 金额: $ 38.02万
• 依托单位: UNIVERSITY OF ILLINOIS AT CHICAGO
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-09-04 至 2012-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7877943
• 关键词: Address; Aorta; Arteries; Artificial Membranes; Atomic Force Microscopy; Beds; Biochemical; Biomechanics; Biomedical Engineering; Blood Vessels; Cardiovascular Diseases; Caveolae; Cell Communication; Cell membrane; Cell physiology; Cells; Cellular Morphology; Cellular biology; Cholesterol; Complex; Coronary artery; Coupling; Cytoskeletal Proteins; Cytoskeleton; Data; Development; Device Designs; Diet; Doctor of Philosophy; Dominant-Negative Mutation; Down-Regulation; Dyslipidemias; Endothelial Cells; Environment; Enzymes; Excision; F-Actin; Family suidae; Fluorescence Anisotropy; Fluorescent Dyes; Functional disorder; Gas-Liquid Chromatography; Goals; High Density Lipoproteins; Human; Image; Impairment; In Vitro; Intracellular Space; Lateral; Lesion; Lipid Bilayers; Lipid Biochemistry; Low-Density Lipoproteins; Measurement; Measures; Mechanical Stress; Mechanics; Membrane; Membrane Fluidity; Membrane Proteins; Methods; Molecular; Molecular Biology; Monomeric GTP-Binding Proteins; Phospholipids; Plasma; Play; Production; Property; Proteins; Pulmonary artery structure; Regulation; Research Personnel; Risk Factors; Role; Simulate; Staging; Sterols; Testing; Three-Dimensional Imaging; Time; Tissues; Toxin; Traction; Vascular remodeling; Very low density lipoprotein; analog; caveolin 1; cell injury; hemodynamics; in vivo; minimally invasive; novel; oxidation; oxidized low density lipoprotein; physical property; programs; research study; response; rho GTP-Binding Proteins; vascular bed; vasoactive agent

DESCRIPTION (provided by applicant): Biomechanical properties of endothelial cells (ECs) are crucially important in regulation of EC mechanotransduction, cell-cell interactions, secretion of vasoactive agents, and vascular remodeling. Our recent studies have shown that EC biomechanical properties are significantly altered by changes in cellular cholesterol suggesting that EC mechanics is impaired under dyslipidemic conditions. The long-term goal of this project is to elucidate the mechanisms responsible for impairment of EC mechanics by dyslipidemia and to determine the impact of these effects on EC function. Our preliminary studies show that oxidized LDL strongly increases EC stiffness supporting the hypothesis that dyslipidemia is important for regulation of EC mechanics. In this study, we propose: (1) To determine the impact of dyslipidemic conditions on mechanical properties of arterial ECs in vitro and ex vivo. First, we will focus on determining the effects of oxLDL and its components on human ECs derived from different arterial beds. Thereafter, we will compare mechanical properties of ECs freshly-isolated from the arteries of normal and hypercholesterolemic pigs. A combination of three biophysical approaches: micropipette aspiration, atomic force and traction force microscopy will be used for comprehensive analysis of EC mechanics. We will further elucidate the relationship between EC mechanics, cytoskeleton organization and cellular cholesterol level using a combination of 3D imaging and lipid biochemistry. (2) To investigate molecular mechanisms responsible for dyslipidemia-induced changes in EC biomechanics. Specifically, we will first determine whether mechanical properties of membrane- cytoskeleton complex depend on the physical properties of the membrane lipid bilayer and/or on the integrity of cholesterol-rich membrane domains and caveolae. Next, we will test the hypothesis that Rho-GTPases and/or PI(4,5)P3, major regulators of membrane-cytoskeleton interactions, are responsible for cholesterol- induced changes in EC mechanics. (3) To elucidate the interplay between dyslipidemia and flow in the regulation of EC mechanics and cytoskeleton remodeling. In this part of the study, we will first investigate the relationship between dyslipidemia and hemodynamic conditions in regulating EC mechanical properties. Finally, we will extend these studies to determine the impact of dyslipidemia on flow-induced cytoskeleton remodeling and NO production.

描述（由申请人提供）：内皮细胞（ECs）的生物力学特性在调节内皮细胞的机械转导、细胞间相互作用、血管活性物质的分泌和血管重塑中至关重要。我们最近的研究表明，细胞胆固醇的变化显著改变了EC的生物力学特性，这表明在血脂异常的情况下EC的力学受到损害。该项目的长期目标是阐明血脂异常导致EC力学损伤的机制，并确定这些影响对EC功能的影响。我们的初步研究表明，氧化LDL强烈增加EC刚度，支持血脂异常对EC力学调节重要的假设。在本研究中，我们建议：(1)确定血脂异常状况对动脉内皮细胞体外和离体力学性能的影响。首先，我们将重点确定oxLDL及其成分对来自不同动脉床的人内皮细胞的影响。之后，我们将比较从正常和高胆固醇血症猪的动脉中分离的内皮细胞的力学性能。结合三种生物物理方法：微移管抽吸，原子力和牵引力显微镜将用于EC力学的综合分析。我们将进一步阐明EC力学、细胞骨架组织和细胞胆固醇水平之间的关系，并结合3D成像和脂质生物化学。(2)探讨血脂异常引起EC生物力学变化的分子机制。具体来说，我们将首先确定膜-细胞骨架复合物的机械特性是否取决于膜脂双分子层的物理特性和/或富含胆固醇的膜结构域和小泡的完整性。接下来，我们将验证rho - gtpase和/或PI(4,5)P3（膜-细胞骨架相互作用的主要调节因子）是胆固醇诱导EC力学变化的原因。(3)阐明血脂异常与血流在EC力学和细胞骨架重塑调控中的相互作用。在这一部分的研究中，我们将首先探讨血脂异常和血流动力学条件在调节EC力学性能中的关系。最后，我们将扩展这些研究，以确定血脂异常对血流诱导的细胞骨架重塑和NO产生的影响。