Impact of dyslipidemia on endothelial biomechanics

血脂异常对内皮生物力学的影响

基本信息

批准号：
7492115
负责人：
Irena Levitan
金额：
$ 38.57万
依托单位：
UNIVERSITY OF ILLINOIS AT CHICAGO
依托单位国家：
美国
项目类别：
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/7492115
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 Condition Coronary artery Coupling Cytoskeletal Proteins Cytoskeleton Data Development Device Designs Diet Disruption 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 Invasive 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 Sus scrofa Testing Three-Dimensional Image Three-Dimensional Imaging Time Tissues Toxin Traction Vascular remodeling Very low density lipoprotein analog caveolin 1 cell injury hemodynamics in vivo novel oxidation oxidized low density lipoprotein physical property programs research study response rho GTP-Binding Proteins vascular bed vasoactive agent

项目摘要

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（EC）的生物力学特性对于 EC 机械转导、细胞间相互作用、血管活性剂的分泌和血管重塑的调节至关重要。我们最近的研究表明，细胞胆固醇的变化会显着改变 EC 的生物力学特性，这表明 EC 力学在血脂异常的情况下会受到损害。该项目的长期目标是阐明血脂异常损害 EC 力学的机制，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 硬度，支持血脂异常对于 EC 力学调节很重要的假设。在本研究中，我们建议：（1）确定血脂异常状况对体外和离体动脉 EC 机械性能的影响。首先，我们将重点确定 oxLDL 及其成分对来自不同动脉床的人类 EC 的影响。此后，我们将比较从正常猪和高胆固醇血症猪的动脉中新鲜分离的 EC 的机械性能。三种生物物理方法的组合：微吸管抽吸、原子力和牵引力显微镜将用于 EC 力学的综合分析。我们将结合 3D 成像和脂质生物化学，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。 (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质双层的物理特性和/或富含胆固醇的膜域和小凹的完整性。接下来，我们将检验以下假设：Rho-GTP 酶和/或 PI(4,5)P3（膜-细胞骨架相互作用的主要调节因子）负责胆固醇诱导的 EC 力学变化。 (3) 阐明血脂异常与血流在 EC 力学和细胞骨架重塑调节中的相互作用。在这部分研究中，我们将首先研究血脂异常与血流动力学条件在调节 EC 机械性能方面的关系。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。