VEGF-C/VEGFR3 AND LYMPHATIC TRANSPORT OF CHOLESTEROL FROM ATHEROSCLEROTIC PLAQUE

VEGF-C/VEGFR3 与动脉粥样硬化斑块中胆固醇的淋巴转运

• 批准号: 8630012
• 负责人: Gwendalyn J Randolph
• 金额: $ 39.23万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-01-20 至 2017-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8630012
• 关键词: Accounting; Address; Adenovirus Vector; Affect; Anastomosis - action; Anatomy; Antibodies; Aorta; Apolipoprotein E; Area; Arterial Fatty Streak; Arteries; Atherosclerosis; Biliary; Binding; Biology; Cannulations; Cholesterol; Clinical; Data; Deuterium; Disease; Disease regression; Dose; Drainage procedure; Excision; Excretory function; Feces; Genetic; Goals; High Density Lipoprotein Cholesterol; High Density Lipoproteins; Human; Inflammation; Label; Laboratories; Left; Lesion; Ligands; Lipid Biochemistry; Lymph; Lymphangiogenesis; Lymphatic; Lymphatic vessel; Measures; Methodology; Methods; Mus; Mutant Strains Mice; Mutate; Operative Surgical Procedures; Pathway interactions; Peripheral; Physicians; Physiologic pulse; Plasma; Process; Recruitment Activity; Research Design; Research Personnel; Role; Route; Signal Transduction; Site; Skin; Smooth Muscle; Staging; Testing; Therapeutic; Thoracic Duct; Tissues; Transplantation; Vascular Endothelial Growth Factor C; Vascular Endothelial Growth Factor Receptor-2; Vascular Endothelial Growth Factor Receptor-3; Vascular Endothelial Growth Factors; cholesterol trafficking; hypercholesterolemia; improved; innovation; macrophage; monocyte; mouse model; mutant; public health relevance; research study; reverse cholesterol transport; tool

PROJECT SUMMARY Our long-term goal is to understand how to remove macrophages and cholesterol from plaques to promote disease regression. We recently discovered that lymphatic vessels serve as the conduits by which cholesterol is removed from the artery wall and other tissues. Reverse cholesterol transport (RCT) is the process by which cholesterol is mobilized from the body for excretion through the feces. With respect to atherosclerosis, the mobilization of cholesterol from macrophages for removal and excretion is most relevant. Over the years, many details emerged regarding how cholesterol is mobilized from macrophages to be loaded onto HDL (HDL-C). However, little was known about how HDL-cholesterol subsequently makes its way out of tissues, including sites like atherosclerotic plaques of the artery wall, to return to plasma before entering pathways for excretion. A handful of clinical or experimental observations led a few physicians in the early 1980's to propose a connection between impaired lymphatic transport and atherosclerosis. However, the quantitative importance of lymphatic vessels in RCT had not been examined, aside from a compelling study that estimated that the net flux of HDL-C through human lymph is substantial. Recently, we utilized experimental mouse models where the patency of lymphatic flow could be modulated by surgical or genetic methods. In skin, we were able to fully abrogate lymphatic flow allowing us to demonstrate that lymphatics are quantitatively the major route for cholesterol mobilization to plasma following macrophage RCT. In atherosclerosis-affected aortic walls, we also used a surgical approach to track deuterium-labeled cholesterol ([2H] D6-cholesterol; D6-cholesterol) from plaques in a pulse-chase manner. Aortas were surgically transplanted into recipients with re-anastomosis of the lymphatic vasculature blocked or not with anti-VEGFR3 mAb. This blockade significantly retained D6- cholesterol in the atherosclerotic aorta, suggesting a key role for lymphatic vessels in cholesterol mobilization from the aorta as observed in skin. In aim 1, we will take a critical next step with refined approaches that will allow us to better quantify the role of lymphatic vessels in cholesterol removal from the aorta and to assess whether the blockade on lymphatics is truly acting locally at the aortic wall. In preliminary data, we show that treating apoE-/- mice with VEGF-C, the ligand for VEGFR3, restores impaired lymphatic transport that occurs following hypercholesterolemia, allowing us to test the hypothesis that VEGF-C acts on lymphatic vessels to therapeutically sustain a critical route for cholesterol transport out of plaques after macrophage cholesterol efflux is stimulated. This hypothesis raises a fundamental question not yet addressed in the field: does effective plaque regression truly depend upon cholesterol removal from plaques, only upon cholesterol removal from macrophages, or perhaps neither? Our study design is ideal to address this fundamental issue while simultaneously digging deeply into a new concept that supporting lymphatic vessel function may help resolve inflammation in the atherosclerotic plaque.

项目摘要 我们的长期目标是了解如何从斑块中去除巨噬细胞和胆固醇，以促进 疾病回归我们最近发现淋巴管是胆固醇 从动脉壁和其他组织中移除。胆固醇反向转运（RCT）是一个过程， 胆固醇从体内动员出来，通过粪便排泄。关于动脉粥样硬化， 胆固醇从巨噬细胞中的移动用于去除和排泄是最相关的。多年来，许多 关于胆固醇如何从巨噬细胞动员以装载到HDL（HDL-C）上的细节出现。 然而，人们对HDL-胆固醇随后如何从组织中排出知之甚少，包括 动脉壁的动脉粥样硬化斑块等部位，在进入排泄途径之前返回血浆。 一些临床或实验观察导致一些医生在20世纪80年代初提出了一种 受损的淋巴转运和动脉粥样硬化之间的联系。然而，数量的重要性 RCT中的淋巴管尚未检查，除了一项令人信服的研究估计， HDL-C通过人淋巴的通量是相当大的。最近，我们利用实验小鼠模型， 淋巴流的开放性可以通过手术或遗传方法来调节。在皮肤上，我们能够完全 消除淋巴流动，使我们能够证明，在数量上，淋巴管是主要途径， 巨噬细胞RCT后胆固醇动员至血浆。在动脉粥样硬化影响的主动脉壁，我们还 使用手术方法追踪氘标记的胆固醇（[2 H] D 6-胆固醇; D 6-胆固醇）， 以脉冲追踪的方式进行斑块。将主动脉手术移植到受者体内， 用抗VEGFR 3 mAb阻断或不阻断淋巴管系统。这种阻断显著保留了D 6- 胆固醇在动脉粥样硬化的主动脉，表明在胆固醇动员淋巴管的关键作用 如在皮肤中观察到的那样。在目标1中，我们将采取关键的下一步改进方法， 使我们能够更好地量化淋巴管在从主动脉清除胆固醇中的作用， 对血管的阻断是否真的在主动脉壁局部起作用。初步数据显示， 用VEGF-C（VEGFR 3的配体）治疗apoE-/-小鼠， 在高胆固醇血症后，使我们能够测试VEGF-C作用于淋巴管的假设， 治疗性维持巨噬细胞胆固醇后胆固醇转运出斑块的关键途径 外排受到刺激。这一假设提出了一个尚未在该领域得到解决的基本问题： 有效斑块消退真正取决于从斑块中去除胆固醇，仅取决于胆固醇的去除 还是两者都没有我们的研究设计是解决这一基本问题的理想选择， 同时深入挖掘一个新的概念，支持淋巴管功能可能有助于解决 动脉粥样硬化斑块中的炎症。