Gross Peter L, Furie Barbara C, Merrill-Skoloff Glenn, Chou Janet, Furie Bruce
Center for Hemostasis and Thrombosis Research, Beth Israel Deaconess Medical Center and Harvard Medical School, Medicine, 330 Brookline Avenue, Boston, MA 02215, USA.
J Leukoc Biol. 2005 Dec;78(6):1318-26. doi: 10.1189/jlb.0405193. Epub 2005 Oct 4.
Circulating tissue factor accumulates in the developing thrombus and contributes to fibrin clot formation. To determine whether tissue factor derived from hematopoietic cells is delivered to the thrombus via tissue factor-bearing microparticles or circulating leukocytes expressing tissue factor on the plasma membrane, we compared the kinetics of tissue factor accumulation in the developing arteriolar thrombus with the time course of leukocyte-thrombus interaction and microparticle-thrombus interaction in the microcirculation of a living mouse using intravital high-speed widefield and confocal microscopy. Tissue factor rapidly accumulated in the developing thrombus, appearing immediately following vessel wall injury, reaching a first peak in approximately 100 s. In contrast, leukocyte-thrombus interaction was not observed until after 2-3 min following vessel wall injury. Maximal leukocyte rolling and firm leukocyte adherence on thrombi in wild-type mice were observed after approximately 8 min and were dependent on P-selectin and P-selectin glycoprotein ligand-1. This delay in P-selectin-dependent leukocyte rolling is a result of time-dependent platelet activation and P-selectin expression on the luminal surface of the thrombus. In contrast, microparticle accumulation in the developing arteriolar thrombus was rapid, and peak accumulation was within 60 s. The accumulation of hematopoietic cell-derived tissue factor in the developing thrombus correlates to the kinetics of microparticle accumulation and does not correlate temporally with leukocyte-thrombus interaction. These results indicate that tissue factor derived from hematopoietic cells is delivered by microparticles during the initial phase of thrombus development in vivo.
循环组织因子在正在形成的血栓中积聚，并有助于纤维蛋白凝块的形成。为了确定源自造血细胞的组织因子是通过携带组织因子的微粒还是通过在质膜上表达组织因子的循环白细胞传递到血栓，我们使用活体高速宽视野和共聚焦显微镜，比较了正在形成的小动脉血栓中组织因子积聚的动力学与活小鼠微循环中白细胞 - 血栓相互作用和微粒 - 血栓相互作用的时间进程。组织因子在正在形成的血栓中迅速积聚，在血管壁损伤后立即出现，在大约100秒时达到第一个峰值。相比之下，直到血管壁损伤后2 - 3分钟才观察到白细胞 - 血栓相互作用。野生型小鼠血栓上最大的白细胞滚动和牢固的白细胞黏附在大约8分钟后观察到，并且依赖于P - 选择素和P - 选择素糖蛋白配体 - 1。这种P - 选择素依赖性白细胞滚动的延迟是血栓腔表面血小板随时间激活和P - 选择素表达的结果。相比之下，正在形成的小动脉血栓中微粒的积聚很快，峰值积聚在60秒内。造血细胞衍生的组织因子在正在形成的血栓中的积聚与微粒积聚的动力学相关，并且在时间上与白细胞 - 血栓相互作用不相关。这些结果表明，在体内血栓形成的初始阶段，造血细胞衍生的组织因子是由微粒传递的。
