Macromolecular Structure of Arterial Walls

动脉壁和动脉瓣是复杂的结构。这些结构的主要元素之一是大分子支架，它提供了执行手头任务的强度和灵活性，要么保持血管中的血液对抗动脉压，要么通过冠状动脉瓣膜的功能维持压力。在过去的几年里，很明显，这些大分子的实际微观结构和组成可以影响不同疾病状态的进展，最明显的是动脉粥样硬化和钙化。为了更好地了解这一过程，我们开始研究动脉血管床中大分子的精细结构，使用一种新的光学成像技术，该技术依赖于胶原和弹性蛋白的非线性激发(NLE)，在未固定的新鲜样品中提供其结构的亚微米图像，并使用荧光显微镜和传统组织学方法直接测量低密度脂蛋白(LDL)结合。在过去的一年里，我们取得了以下进展：1)我们建立了猪心脏主动脉瓣中大分子成分的低密度脂蛋白结合分析方法。这是使用人低密度脂蛋白亲和柱并将大分子匀浆直接应用于柱上而完成的。利用高离子强度去除伴随的大分子，我们发现大分子核心蛋白是与低密度脂蛋白结合的主要试剂。我们用凝胶电泳和质谱学技术证实了这一观察结果。纯化的核心蛋白聚糖也被发现与人类低密度脂蛋白高度相关。2)为了研究核心蛋白聚糖与动脉壁低密度脂蛋白结合的组织学相关性，已研制出具有活性和特异性的核心蛋白聚糖荧光抗体。3)筛选与核心蛋白聚糖-低密度脂蛋白相互作用的分子已经开始。这可能为早期动脉粥样硬化的治疗提供一种新的治疗途径。

The arterial wall and arterial valves are complex structures. One of the major elements of these structures is the macromolecular scaffold that provides the strength and flexibility to perform the task in hand either retaining the blood in vessels against the arterial pressure or maintaining pressure via the function of coronary valves. In the last several years it has become apparent that the actual microstructure and composition of these macromolecules could influence the progress of different disease states most notably atherosclerosis and value calcification. To gain a better understanding of this process, we have embarked on studies to understand the fine structure of the macromolecules in arterial vascular bed using a novel optical imaging technique that relies on the non-linear excitation (NLE) of collagen and elastin to provide sub-micron images of their structure in unfixed fresh samples together with direct measures oflow density lipoprotein particles (LDL) binding using fluorescence microscopy and conventional histology methods. Over the last year we have made the following progress: 1) We have developed the binding assay for LDL for macromolecular consitutents in the aortic valve of the pig heart. This was accomplished using a human LDL affinity column and applying the macromolecule homogenates directly on the column. Using high ionic strength to remove the associated macromolecules we have found that the macromolecule Decorin is the dominate agent binding to LDL. We confirmed this observation using gel electrophoresis and mass spectroscopy techniques.Purified Decorin was also found to highly associate with human LDL. 2) Active and specific fluorescent antibodies for Decorin have been developed for the histological correlation of Decorin with LDL binding in arterial walls. 3) Screening of molecules to interact with the Decorin-LDL interaction have begun. These may provide a new therapuetic approach to the treatment of atherosclerosis at is earlies stage.