Interaction of Macrophages with Marix-Associated Lipoproteins

描述(由申请人提供)：本文提出的研究将为动脉粥样硬化形成的早期步骤提供新的见解。我们假设，当巨噬细胞与基质保留的低密度脂蛋白聚集体接触时，会发生快速的胆固醇酯转移。这导致巨噬细胞膜胆固醇水平增加，细胞形态和迁移能力发生变化。这一过程可能解释了为什么动脉粥样硬化病变内的巨噬细胞继续摄取滞留的脂蛋白并发育成不活动的泡沫细胞。为了研究这一假说，我们将利用体外组织培养的延时共聚焦荧光成像来检测巨噬细胞在最初接触基质相关脂蛋白时所引起的形态变化。此外，通过监测荧光胆固醇类似物从低密度脂蛋白到巨噬细胞的转移，可以直接观察质膜胆固醇水平的变化。最后，研究将把我们对体外组织模型的观察扩展到体内检测动脉粥样硬化动物模型中巨噬细胞的迁移行为。活体显微镜将被用来量化单核/巨噬细胞的渗出。结果可能最终导致促进动脉粥样硬化病变消退的创新方法。

DESCRIPTION (provided by applicant): The studies proposed herein will provide new insights into the early steps of atherogenesis. We hypothesize that as macrophages come into contact with matrix-retained LDL aggregates, rapid cholesterol ester transfer occurs. This results in an increase in macrophage membrane cholesterol levels and changes in cell morphology and migratory ability. This process may explain why macrophages within atherosclerotic lesions continue to take up retained lipoproteins and develop into nonmotile foam cells. To investigate this hypothesis, time-lapse confocal fluorescence imaging of in vitro tissue cultures will be utilized to examine macrophage morphological alterations induced during their initial contact with matrix-associated lipoproteins. Further, monitoring the transfer of a fluorescent cholesterol analog from LDL to macrophages allows direct observation of changes in plasma membrane cholesterol levels. Finally, studies will extend our observations on in vitro tissue models to in vivo examination of macrophage migratory behavior in animal models of atherosclerosis. Intravital microscopy will be used for quantification of monocyte/macrophage diapedesis. Results may eventually lead to innovative methods of promoting atherosclerotic lesion regression.