From the Thrombosis and Hemostasis Program, Division of Hematology and Oncology, Department of Medicine, University of North Carolina at Chapel Hill.
Arterioscler Thromb Vasc Biol. 2018 Apr;38(4):709-725. doi: 10.1161/ATVBAHA.117.309846. Epub 2018 Feb 8.
Tissue factor (TF) is the high-affinity receptor and cofactor for factor (F)VII/VIIa. The TF-FVIIa complex is the primary initiator of blood coagulation and plays an essential role in hemostasis. TF is expressed on perivascular cells and epithelial cells at organ and body surfaces where it forms a hemostatic barrier. TF also provides additional hemostatic protection to vital organs, such as the brain, lung, and heart. Under pathological conditions, TF can trigger both arterial and venous thrombosis. For instance, atherosclerotic plaques contain high levels of TF on macrophage foam cells and microvesicles that drives thrombus formation after plaque rupture. In sepsis, inducible TF expression on monocytes leads to disseminated intravascular coagulation. In cancer patients, tumors release TF-positive microvesicles into the circulation that may contribute to venous thrombosis. TF also has nonhemostatic roles. For instance, TF-dependent activation of the coagulation cascade generates coagulation proteases, such as FVIIa, FXa, and thrombin, which induce signaling in a variety of cells by cleavage of protease-activated receptors. This review will focus on the roles of TF in protective hemostasis and pathological thrombosis.
组织因子（TF）是因子（F）VII/VIIa 的高亲和力受体和辅助因子。TF-FVIIa 复合物是血液凝固的主要启动子，在止血中起着至关重要的作用。TF 表达于血管周围细胞和器官及体表的上皮细胞上，形成止血屏障。TF 还为大脑、肺和心脏等重要器官提供额外的止血保护。在病理条件下，TF 可引发动脉和静脉血栓形成。例如，动脉粥样硬化斑块中的巨噬细胞泡沫细胞和微囊泡含有高水平的 TF，可在斑块破裂后引发血栓形成。在脓毒症中，单核细胞诱导性 TF 表达可导致弥散性血管内凝血。在癌症患者中，肿瘤将 TF 阳性微囊泡释放到循环中，可能导致静脉血栓形成。TF 还具有非止血作用。例如，TF 依赖性凝血级联的激活产生凝血蛋白酶，如 FVIIa、FXa 和凝血酶，通过切割蛋白酶激活受体在各种细胞中诱导信号转导。本综述将重点介绍 TF 在保护性止血和病理性血栓形成中的作用。
