Macromolecular Structure of Arterial Walls

动脉壁和动脉瓣膜是复杂的大分子结构。这些结构的主要元素之一是支架，它提供了完成手头任务的力量和灵活性，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。这些研究已经确定核心蛋白是瓣叶中低密度脂蛋白的主要结合部位。在过去的一年里，我们取得了以下进展：1)我们目前正在确认我们在更一般的血管床上使用我们两年前描述的肾动脉口转流器的瓣叶研究。正在对这种血管结构的蛋白质样本进行评估，以确定在瓣膜中发现的类似结合模式是否在外周血管系统中发挥作用。2)使用我们的低密度脂蛋白-核心蛋白结合筛选试验，我们已经评估了几个用于动脉粥样硬化倾向小鼠模型的临床前筛查的分子。这些研究旨在寻找干扰低密度脂蛋白-核心蛋白相互作用的分子，然后评估这些分子是否延缓或抑制小鼠动脉粥样硬化的形成。目前，我们已经筛选并拒绝了简单的硫酸软骨素和一些肝素的同系物，因为它们的亲和力太低，尽管在高浓度时可以表现出很强的结合抑制作用。目前，我们正在评估其他几个完成这项任务的候选分子，以及评估对这种相互作用进行更完整的化学筛选的可能性。

The arterial wall and arterial valves are complex macromolecular structures. One of the major elements of these structures is the 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 of low density lipoprotein particles (LDL) binding using fluorescence microscopy and conventional histology methods. These studies have identified Decorin as a major binding site for LDL in the valve leaflet. Over the last year we have made the following progress: 1) We are currently confirming our studies in the valve leaflet in the more general vascular bed using the renal artery ostia diverter we described two years ago. Protein samples for this vascular structure are being evaluated to establish whether a similar binding pattern discovered in the valves is in play in the peripheral vasculature. 2) Using our screening assay for LDL-Decorin binding, we have been evaluated several molecules for use in a pre-clinical screen in an atheroma prone mouse model. These studies will be designed to look for molecules that interfere with the LDL-Decorin interaction and then evaluate whether these molecules delay or inhibit atheroma formation in the mouse. Currently we have screened and rejected simple chondroitin sulfates and some homologs of heparin as being too low affinity for this purpose, though strong inhibion of binding can be demonstrated at high concentration. Currently we are evaluating several other candidate molecules to accomplish this task as well as evaluating the potential for conducting a more complete chemical screen of this interaction.