Managing Atherosclerosis by Modulating HDL Function

项目摘要/摘要 动脉粥样硬化是世界范围内导致人类死亡的主要原因。人们对……一直很感兴趣 开发治疗这种疾病的新疗法，其作用机制与目前 可获得的药物。一个有希望的策略是增强高密度脂蛋白(HDL)的功能。高密度脂蛋白 促进胆固醇反向转运(RCT)，将多余的胆固醇从外周组织转移到肝脏 淘汰赛。这项拟议的研究得到了最近的强劲进展的支持，试图推动一部小说 改善体内高密度脂蛋白功能以对抗动脉粥样硬化的超分子策略。 建议的研究建立在我们研究计划的成功基础上，该研究计划由NHLBI R01拨款资助 过去的八年里。尽管载脂蛋白模拟多肽领域取得了实质性进展，包括 在1期和2期人体临床试验中对几个候选对象的评估，固有的药理学 线状多肽的典型缺陷一直是推动高密度脂蛋白发展的主要障碍。 在临床上调节多肽。我们提出的研究旨在开发一类新的化学类型 这可以概括螺旋脂蛋白模拟物的功能属性，但没有其固有的局限性。 我们已经确定，经过适当设计的八个残基自组装的环D，L-a-肽是 有效的高密度脂蛋白调节剂，可重塑人和小鼠血浆高密度脂蛋白并提高胆固醇 巨噬细胞的外流。这些多肽特别增加了前β-高密度脂蛋白颗粒的水平 (高密度脂蛋白被认为是最抗动脉粥样硬化的亚种)，降低低密度脂蛋白-胆固醇和甘油三酯水平， 并在小鼠疾病模型中促进抗炎作用，同时预防动脉粥样硬化。 环D，L-a-肽的非生物结构克服了通常与 线状多肽，如低血清/血浆稳定性和高生产成本等。 拟议研究的具体目标1和2涉及一)实施一系列以机制为基础的 优化和更好地描述铅的作用方式的功能生物测定和生物物理测定 化合物，以及ii)在体内建立所选环肽的体内药理学、毒理学和有效性 领先的动脉粥样硬化小鼠模型。拟议研究的具体目标3是基于一项意想不到的、 在我们最近的研究过程中进行了引人注目的观察。我们发现三氟乙酸酯(TFA)， 口服或非肠道给药，可使血浆胆固醇水平呈剂量依赖性降低，并防止 动脉粥样硬化在体内的发展。这一发现的潜在影响是广泛的，因为 几乎所有的合成肽，在不同的生物环境中使用，都含有TFA反离子，其结果是 制备高效液相色谱分离纯化。因此，TFA在体外和体内对细胞代谢的影响必须 有特点的和理解的。我们提出了一系列基于假设的体外和体内研究，以确定 观察到的TFA介导的抗动脉粥样硬化作用的机制和一般性。

PROJECT SUMMARY/ABSTRACT Atherosclerosis is the leading cause of human mortality worldwide. There has been a great interest in developing novel therapeutics for this disease that function via an orthogonal mechanism of action to currently available drugs. One promising strategy is to enhance the function of high-density lipoproteins (HDLs). HDLs facilitate reverse cholesterol transport (RCT) to transfer excess cholesterol from peripheral tissues to the liver for elimination. The proposed research, supported by strong recent progress, seeks to advance a novel supramolecular strategy for improving HDL function in vivo to combat atherosclerosis. The proposed studies build on the successes of our research program, funded by an NHLBI R01 grant over the past eight years. Despite substantial progress in the field of apolipoprotein mimetic peptides, including evaluation of several candidates in phase 1 and 2 human clinical trials, the inherent pharmacological shortcomings typically associated with linear peptides have been a major impediment to advancing HDL- modulating peptides through the clinic. Our proposed research seeks to develop a novel class of chemotypes that can recapitulate the functional attributes of helical lipoprotein mimetics, but without their inherent limitations. We have established that appropriately designed eight-residue self-assembling cyclic D,L-a-peptides are effective HDL modulating agents that can remodel human and mouse plasma HDLs and enhance cholesterol efflux from macrophage cells. These peptides specifically increase the level of pre-beta HDL particles (subspecies of HDLs considered to be the most anti-atherogenic), reduce LDL-cholesterol and triglyceride levels, and promote anti-inflammatory effects with concomitant prevention of atherosclerosis in mouse disease models. The abiotic structure of cyclic D,L-a-peptides overcomes many of the shortcomings typically associated with linear peptides, such as low serum/plasma stability and high production costs, among others. Specific aims 1 and 2 of the proposed research involve i) implementing a series of mechanism-based functional bioassays and biophysical assays to optimize and better characterize the mode of action of the lead compounds, and ii) establishing in vivo pharmacology, toxicology, and efficacy of selected cyclic peptides in two leading mouse models of atherosclerosis. Specific aim 3 of the proposed research is based on an unexpected, remarkable observation made in the course of our recent studies. We have discovered that trifluoroacetate (TFA), administered orally or parenterally, causes dose-dependent reductions in plasma cholesterol levels and prevents the development of atherosclerosis in vivo. The implications of this discovery are potentially broad because nearly all synthetic peptides, employed across diverse biological settings, contain TFA counterions resulting from purification by preparative HPLC. As such, the effects of TFA on cellular metabolism in vitro and in vivo must be characterized and understood. We propose a series of hypothesis-based in vitro and in vivo studies to define the mechanism and generality of the observed TFA-mediated anti-atherosclerosis effects.