Role of Vascular Heterogeneity in Thrombosis

描述(由申请人提供)： 动脉和静脉循环中的血栓性疾病是美国发病率和死亡率的主要原因。在小鼠血栓形成模型中的体内研究开始挑战血栓起始和延长的范式，主要是基于体外和体外研究。血液蛋白质和细胞与血管壁的相互作用受到血管内剪切力和其他血管床特有因素的影响，包括内皮细胞的异质性。血管床的这种异质性导致了不同血管部位血栓形成过程的不同。我们开发了一种独特的Brightfield和共焦活体显微镜系统来研究体内血栓的形成。用这台仪器测定了激光诱导小鼠提睾肌内皮细胞损伤后微动脉血栓形成的动力学，开始探索血栓成分的掺入，并显示了P-选择素和PSGL-1在血栓形成中的作用。在这里，我们建议探索在附加的血管床上血栓形成的差异，包括提睾肌的小静脉和具有独特内皮细胞群的软脑膜的小动脉和小静脉。我们将在三种血栓形成的小鼠模型中，研究血栓组分在提睾肌和软脑膜材料的小动脉和小静脉中的结合和血栓形成的动力学。我们将确定血小板、纤维蛋白、组织、因子、白细胞、红细胞和微粒在血栓生长中的掺入；血栓形成的动力学；血栓的稳定性和不同血栓模型中内皮下蛋白的暴露。我们将通过确定内皮细胞和血小板P-选择素在三种不同血管床血栓形成模型中的重要性来扩展我们对P-选择素在血栓形成中的作用的研究。为了区分P-选择素在血小板和内皮细胞中的作用，我们将使用骨髓移植来产生只有一种细胞类型的P-选择素的小鼠，并重复这些小鼠在不同血管床上形成血栓的研究。为了探讨凝血酶激活在血栓形成中的重要性，我们将重复PAR 4和PAR 3基因缺失小鼠在不同血管床和不同血栓形成模型中的血栓形成研究。

DESCRIPTION (provided by applicant): Thrombotic disease in both the arterial and venous circulation is a major cause of morbidity and mortality in the United States. In vivo studies in mouse models of thrombosis are beginning to challenge paradigms of initiation and extension of thrombi largely based on in vitro and ex vivo studies. Interaction of blood proteins and cells with the vessel wall is influenced by shear forces within the vessel and by other vascular bed specific factors including heterogeneity of endothelial cells. This heterogeneity of vascular beds leads to differences in the process of thrombus formation at various vascular sites. We have developed a unique brightfield and confocal intravital microscopy system to study thrombus formation in vivo. Using this instrument we have determined the kinetics of thrombus formation after laser induced endothelial cell injury in the arterioles of the mouse cremaster muscle, have begun to explore the incorporation of components of the thrombus and have shown a role for P-selectin and PSGL-1 in thrombus formation. Here we propose to explore differences in thrombus formation in additional vascular beds including venules of the cremaster muscle and the arterioles and venules of the pia mater with its unique endothelial cell population. We will study the incorporation of thrombus components and kinetics or thrombus formation in the arterioles and venules of the cremaster muscle and the pia materin three mouse models of thrombosis. We will determine incorporation of platelets, fibrin, tissue, factor, white cells, red cells and microparticles into the growing thrombus; the kinetics of thrombus formation; the stability of the thrombus and the exposure of sub-endothelial proteins in the different thrombosis models. We will extend our studies of the role of P-selectin in thrombus formation by determining the importance of endothelial cell and platelet P-selectin in three models of thrombus formation in different vascular beds. To distinguish the roles of P-selectin from platelets and endothelial cells we will use bone marrow transplant to generate mice that have P-selectin in only one cell type and repeat the studies of thrombus formation in these mice in the different vascular beds. In order to explore the importance of thrombin activation of platelets in thrombus formation we will repeat the studies of thrombus formation in the various vascular beds and in the different models of thrombosis in PAR 4 and PAR 3 null mice.