Multidisciplinary Approaches to HDL Structure, Assembly and Function

描述(由申请人提供)：该计划项目拨款的中心假设是，平台蛋白apoA-I是一种构象动态支架，促进了其他高密度脂蛋白和脂类重塑因子之间的相互作用，这些因素对动脉壁产生了强大的生物效应。根据最近的计算和实验观察，我们认为apoA-I中的特定区域为LCAT、PON1、CETP、PLTP、ABCA1和Abcg1等关键抗动脉粥样硬化蛋白的对接提供了一个重要的和可测试的机制。在临床、流行病学、动物和遗传学研究中，高密度脂蛋白胆固醇与心血管疾病风险之间存在明显的负相关。这些观察结果引发了以高密度脂蛋白为靶点进行干预的强烈兴趣。然而，最近的研究质疑高密度脂蛋白-C是否与人类的心血管疾病状态有关，或者升高高密度脂蛋白-C是否一定具有治疗作用。我们在这项提案中的目标是使用多学科团队的方法来前所未有地详细地了解apoA-I平台功能的分子机制，包括使apoA-I能够作为平台功能的分子机制。通过PPG机制，我们建议使用三种集成的创新方法来实现我们的目标：i)计算模拟和分子模拟，ii)apoA-I及其伙伴蛋白的化学交联和定点突变，iii)用质谱学和基于细胞的分析进行结构-功能探测，以探索高密度脂蛋白组成的临床影响，并测试不同于高密度脂蛋白-C的评估高密度脂蛋白功能的新方法。 我们提议的研究计划集中在三个主题上：项目1：高密度脂蛋白汇编的结构基础-Jere Segrest，项目负责人(UAB)；项目2：高密度脂蛋白成熟的结构基础-W.Sean Davidson，项目负责人(U·辛辛那提)；项目3：LCAT缺陷者的高密度脂蛋白结构/功能-Jay Heinecke，项目负责人(U·华盛顿)。这三个主题涉及三位世界级科学家之间的动态互动，他们拥有独特(和互补)的专业领域，都在研究高密度脂蛋白，这是一种独特的合作，不太可能存在于任何单一机构，在科学和高密度脂蛋白领域也是罕见的。每个项目都提出了几个项目之间的协作研究，如果没有PPG，这些研究是不可能的。所有项目将广泛使用四个核心，它们是PPG的关键组成部分：核心A：行政-Jere Segrest，核心领导者(UAB)；核心B：计算生物学-Martin Jones，核心领导者(UAB)；核心C：高密度脂蛋白定量-Tomas Vaisar，核心领导者(U华盛顿)；核心D：蛋白质生产和相互作用-W.肖恩·戴维森，核心领导者(U·辛辛那提)。总之，我们认为，要解决高密度脂蛋白在血管生物学中的作用，关键是将模型系统研究与计算和功能方法相结合，并在翻译研究中测试由此产生的想法。重要的是，我们相信我们的调查团队拥有被证明的专业知识和协同能力来追求这一确切的方法。

DESCRIPTION (Provided by applicant): The central hypothesis of this Program Project Grant, "Multidisciplinary Approaches to HDL Structure, Assembly and Function", is that the platform protein, apoA-I, is a conformationally dynamic scaffold that facilitates interactions among other HDL proteins and lipid remodeling factors that exert potent biological effects on the artery wall. On the basis of recent computational and experimental observations, we propose that specific regions in apoA-I provide an important and testable mechanism for docking of key proposed anti-atherosclerotic proteins, such as LCAT, PON1, CETP, PLTP, ABCA1 and ABCG1. There is a robust, inverse association of HDL-C with cardiovascular disease risk in clinical, epidemiological, animal and genetic studies. These observations have triggered intense interest in targeting HDL for intervention. However, recent studies call into question whether HDL-C relates to CVD status in humans or elevating HDL-C is necessarily therapeutic. Our objective in this proposal is to use a multidisciplinary team approach to understand, in unprecedented detail, the molecular mechanisms for the platform functions of apoA-I, including the molecular mechanisms that enable apoA-I to function as a platform. Through the PPG mechanism, we propose to achieve our objective by use of three integrated innovative methods: i) computational simulation and molecular modeling, ii) chemical crosslinking and site-directed mutagenesis of apoA-I and its partner proteins, iii) structure-function probing with mass spectrometric and cell-based assays that will explore the clinical impact of HDL composition and test new ways of assessing HDL functionality that are distinct from that of HDL-C. Our proposed research program centers on three topics: Project 1: Structural basis of HDL assembly―Jere Segrest, Project Leader (UAB); Project 2: Structural basis of HDL maturation―W. Sean Davidson, Project Leader (U. Cincinnati); Project 3: HDL structure/function in LCAT deficient humans―Jay Heinecke, Project Leader (U. Washington). These three topics involve dynamic interactions among three world class scientists with unique (and complementary) areas of expertise all studying HDL, a unique collaboration unlikely to exist at any single institution and rare in science and in the HDL field. Each project has proposed several collaborative studies among projects that would not be possible in the absence of a PPG. All projects will make extensive use of four Cores, which are key components of the PPG: CORE A: Administration―Jere Segrest, Core Leader (UAB); CORE B: Computational biology―Martin Jones, Core Leader (UAB); CORE C: HDL quantitation―Tomas Vaisar, Core Leader (U. Washington); CORE D: Protein production and interaction―W. Sean Davidson, Core Leader (U. Cincinnati). In summary, we believe that to address HDL's role in vascular biology it will be critical to combine model system studies with computational and functional approaches and to test the resulting ideas in translational studies. Importantly, we believe that our team of investigators has the demonstrated expertise and synergy to pursue this exact approach.