Cellular and Molecular Biology of Lipoprotein Metabolism

描述（由申请人提供）： 本申请代表了一个计划项目的延续，该计划项目的总体目标是阐明高密度脂蛋白（HDL）的胆固醇转运功能对预防动脉粥样硬化发展的贡献。将研究HDL介导胆固醇逆向转运（RCT）的机制，RCT是胆固醇从外周细胞中清除并转运至肝脏以从体内清除的过程。实验将在分子、细胞、整个动物和人类水平上以协调的方式进行。该项目由三个密切相关和互动的项目组成。项目1建议使用新的测定方法研究HDL的数量和质量对细胞和血清之间不同途径胆固醇净流量的影响，以及巨噬细胞泡沫细胞中胆固醇酯液滴水解对胆固醇流量的影响。项目2旨在了解人载脂蛋白（apo）A-I的结构-功能和分子机制，该蛋白质通过与ATP结合盒转运蛋白Al相互作用结合脂质并产生HDL颗粒。项目3涉及使用体内方法来了解RCT的分子调控。将在小鼠中评价apoA-I突变和血浆因子（卵磷脂-胆固醇酰基转移酶、胆固醇酯转移蛋白、磷脂转移蛋白）对HDL代谢和巨噬细胞RCT影响的机制。将使用评估人体RCT的新方法来检查HDL数量和质量在这种情况下的影响。组成该计划项目的研究人员在脂质和脂蛋白代谢方面有着相似的兴趣和目标，同时提供广泛的科学专业知识。这些研究人员所涵盖的科学学科包括生物化学、细胞生物学、分子生物学、蛋白质化学、动物生理学和医学。该计划由三个核心实验室支持：1）行政/中央服务核心，2）组织培养核心和3）脂蛋白核心。在血浆HDL胆固醇水平升高的人群中，早发冠状动脉疾病的发病率降低。这种保护作用的原因还不完全清楚，该项目旨在揭示HDL有益特性的分子机制。

DESCRIPTION (provided by applicant): This application represents a continuation of a Program Project whose overall goal is to elucidate the contributions of the cholesterol transport functions of high density lipoprotein (HDL) to the prevention of the development of atherosclerosis. The mechanisms by which HDL mediates reverse cholesterol transport (RCT), the process whereby cholesterol is removed from peripheral cells and transported to the liver for clearance from the body, will be investigated. Experiments will be conducted in a coordinated fashion at the molecular, cellular, whole animal and human levels. This Program Project consists of three closely related and interactive projects. Project 1 proposes to investigate using novel assays the effects of HDL quantity and quality on the net flux of cholesterol by different pathways between cells and serum, and the impact on cholesterol flux of the hydrolysis of cholesteryl est droplets in macrophage foam cells. Project 2 aims to understand human apolipoprotein (apo) A-l structure-function and the molecular mechanisms by which this protein binds lipids and creates HDL particles by interaction with the ATP-binding cassette transporter Al. Project 3 involves the use of in vivo methods to understand the molecular regulation of RCT. The mechanisms responsible for the effects of apoA-l mutations and plasma factors (lecithin-cholesterol acyltransferase, cholesteryl ester transfer protein, phospholipid transfer protein) on HDL metabolism and macrophage RCT will be evaluated in mice. New methods for the assessment of RCT in human will be used to examine the influence of HDL quantity and quality in this setting. The group of investigators comprising this Program Project share similar interests and goals in lipid and lipoprotein metabolism while providing broad scientific expertise. The scientific disciplines encompassed by these investigators include biochemistry, cell biology, molecular biology, protein chemistry, animal physiology and medicine. The program is supported by three core laboratories: 1) Administrative/Central Service Core, 2) Tissue Culture Core and 3) Lipoprotein Core. The incidence of premature coronary artery disease is reduced in human populations with elevated levels of plasma HDL cholesterol. The reasons for this protective effect are not understood fully and this project seeks to uncover the molecular mechanisms underlying the beneficial properties of HDL.