High Density Lipoprotein Biogenesis and Speciation

高密度脂蛋白生物发生和形态形成

基本信息

批准号：
9164514
负责人：
Henry J. Pownall
金额：
$ 60.06万
依托单位：
METHODIST HOSPITAL RESEARCH INSTITUTE
依托单位国家：
美国
项目类别：
财政年份：
2016
资助国家：
美国
起止时间：
2016-08-01 至 2020-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9164514
关键词：
ATP binding cassette transporter 1 Address Amino Acids Animals Antiatherogenic Apolipoprotein A-I Apolipoproteins B Atherosclerosis Biogenesis Biophysics Cardiovascular Diseases Cell membrane Cellular biology Chemicals Cholesterol Circular Dichroism Competence Complex Dependovirus Disease Outcome Dissociation Economics Esterification Event Excretory function Family Functional disorder Gene Delivery Head Hepatic Hepatocyte High Density Lipoprotein Cholesterol High Density Lipoprotein therapy High Density Lipoproteins Human Immune In Vitro Intervention Kinetics LDL Cholesterol Lipoproteins Lecithin Lipid Binding Lipids Lipoproteins Liver Mediating Membrane Membrane Lipids Methods Modeling Modification Molecular Molecular Conformation Molecular Target Mus Pathway interactions Patients Peptide Signal Sequences Performance Peripheral Pharmaceutical Preparations Phosphatidylcholine-Sterol O-Acyltransferase Phospholipids Physiology Plasma Play Precipitation Process Production Proline Property Proteins Public Health Quality of life Risk Factors Role Scientist Side Site-Directed Mutagenesis Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization Structure Surface Tail Testing Therapeutic Thin Layer Chromatography Time Tissues Turbidimetry Variant analog base chemical kinetics cost crosslink design improved in vivo interest intrahepatic macrophage mimetics monolayer multidisciplinary novel particle peptide structure protein activation reverse cholesterol transport uptake

项目摘要

Cardiovascular disease (CVD) is a public health challenge with a major economic and quality-of-life impact on its victims and their families. Impressive inroads have been made in the management of some CVD lipid risk factors; the statin class of hypolipidemic drugs reduces the number of CVD events by reducing plasma levels of low density lipoprotein-cholesterol. Reduction in CVD via the modification of other lipid-risk factors has been a challenge, especially raising the plasma concentrations of high density lipoproteins-cholesterol (HDL-C), in a cardioprotective way; attempts to reduce CVD via raising HDL-C have not been uniformly successful. Many scientists now appreciate that the mechanistic connections between HDL and atheroprotection are more complex than once thought and that a greater focus on HDL function, rather that HDL-C concentrations alone, is needed. HDL plays a role in reverse cholesterol transport (RCT), the transport of cholesterol in peripheral tissues, including macrophages in the subendothelial space of the arterial wall, to the liver for disposal. The major RCT steps are macrophage cholesterol efflux, HDL-C esterification in plasma, and hepatic disposal, which directs some cholesterol to excretion thereby reducing the total body cholesterol burden. Recent evidence is that not all HDL are the same, i.e., HDL are speciated according to composition, structure, and likely function. Several studies have shown cholesterol efflux to apo B-depleted plasma is lower in CVD patients, independent of HDL-C concentrations. This difference must be due to differences in the “quality” of HDL in patients vs. those without CVD. Some HDL species may be better cholesterol acceptors; apo AI may play a direct role in efflux. Moreover, mimetics based on an optimized apo AI structure may be a promising therapeutic strategy. The aims of this application focus on three aspects of HDL and apo AI structure and/or function— speciated biogenesis of HDL with intact signal peptides (SP); the mechanism of efflux from macrophages giving nascent HDL and microsolubilization as a surrogate for nascent HDL formation, and optimization of apo AI structure for RCT. This background and rationale gave rise to three aims: Aim 1: To test the hypothesis that the biogenesis of HDL containing apos with intact signal peptides (SPs) is unique and speciated, and forms unique HDL species with distinct compositions and functions. Aim 2: To test a novel, hypothetical “pancake” model of phospholipid microsolubilization by apo AI, which yields rHDL, the in vitro analog of nascent HDL produced by hepatocytes and MФ cholesterol efflux. Aim 3: To test the hypothesis that conserved amino acid residues in apo AI are essential to its structure and function. Completion of these aims will reveal new molecular targets for cardioprotective HDL therapies. These aims will be addressed by multidisciplinary in vitro and in vivo approaches that includes chemical kinetics, cell biology, lipid and protein analyses, AAV-mediated gene delivery in vivo, high performance thin-layer chromatography, immune-blotting and precipitation methods, chemical cross-linking, MALDI MS, site-directed mutagenesis, circular dichroism, and kinetic turbidimetry.

心血管疾病（CVD）是一项公共卫生挑战，对经济和生活质量造成重大影响对受害者及其家人的影响在管理方面取得了令人印象深刻的进展。一些 CVD 脂质危险因素；他汀类降血脂药物可减少 CVD 事件的数量通过修饰降低低密度脂蛋白胆固醇的血浆水平，从而减少 CVD。其他脂质风险因素一直是一个挑战，特别是提高高密度脂蛋白的血浆浓度脂蛋白胆固醇 (HDL-C)，以保护心脏的方式尝试通过提高 HDL-C 来减少 CVD；许多科学家现在还没有一致地认识到这种机械联系。 HDL 和动脉粥样硬化之间的关系比以前想象的更加复杂，并且更加关注 HDL 功能（而不是单独的 HDL-C 浓度）在逆转胆固醇方面发挥作用。运输（RCT），胆固醇在外周组织中的运输，包括巨噬细胞动脉壁的内皮下空间，到肝脏进行处理，主要的 RCT 步骤是巨噬细胞。胆固醇外流、血浆中 HDL-C 酯化以及肝脏处理（引导一些胆固醇）最近的证据表明，并非所有高密度脂蛋白都是如此。同样，即 HDL 根据组成、结构和可能的功能进行了一些研究。研究表明，CVD 患者中胆固醇流出至 APO B 耗尽的血浆较低，与 HDL-C 无关这种差异一定是由于患者体内 HDL 的“质量”不同所致。一些 HDL 物种可能是更好的胆固醇受体，apo AI 可能在其中发挥直接作用。此外，基于优化的 apo AI 结构的模拟物可能是一种有前途的治疗方法。战略。本申请的目标集中于HDL和apo AI结构和/或功能的三个方面—— HDL 与完整信号肽 (SP) 的物种生物发生；巨噬细胞流出的机制；提供新生 HDL 和微溶解作为新生 HDL 形成和优化的替代品 RCT 的 apo AI 结构这一背景和基本原理产生了三个目标：目标 1：检验含有完整信号肽 (SP) 的 HDL 生物发生的假设是独特和特定的，并形成具有独特组成和功能的独特HDL物种。目标 2：通过 apo AI 测试一种新颖的、假设的磷脂微溶解“煎饼”模型，产生 rHDL，这是肝细胞和 MФ 胆固醇产生的新生 HDL 的体外类似物外流。目标 3：检验 apo AI 中的保守氨基酸残基对其结构至关重要的假设和功能。这些目标的完成将为心脏保护性高密度脂蛋白疗法揭示新的分子靶点。目标将通过多学科的体外和体内方法来实现，其中包括化学方法动力学、细胞生物学、脂质和蛋白质分析、AAV 介导的体内基因传递、高性能薄层色谱法、免疫印迹和沉淀法、化学交联、MALDI MS、定点诱变、圆二色性和动力学比浊法。