Tissue Factor: An Essential Mediator of Hemostasis and Trigger of Thrombosis.

TLDR: The roles of TF in protective hemostasis and pathological thrombosis are focused on and coagulation proteases, such as FVIIa, FXa, and thrombin are described.

Abstract: 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