Vävnadsfaktorfaktor

Vävnadsfaktorfaktor, often abbreviated as TF, is a transmembrane protein that plays a crucial role in the initiation of the blood coagulation cascade. Also known as thromboplastin or factor III, it is primarily found on the surface of cells outside the blood vessels, such as fibroblasts and smooth muscle cells. When a blood vessel is injured, TF is exposed to the circulating blood.

Upon exposure, TF binds to activated factor VII (FVIIa), forming a complex that activates factor X (FX) and, to a lesser extent, factor IX (FIX). This TF-FVIIa complex is considered the primary initiator of coagulation. The activation of FX leads to the formation of thrombin, a key enzyme in the coagulation process, which ultimately converts fibrinogen into fibrin, forming a stable blood clot.

TF's role is not limited to hemostasis; it also participates in other physiological and pathological processes, including inflammation, angiogenesis, and cancer progression. Its expression can be upregulated by inflammatory cytokines, contributing to a prothrombotic state in various diseases. Due to its central role in coagulation, TF and its interactions are targets for anticoagulant therapies.