TAFI: regulating the cross talk between coagulation and fibrinolysis TAFI: Regulierung der Wechselwirkung zwischen Gerinnung und Fibrinolyse

Thrombin activates thrombin-activatable fibrinolysis inhibitor (TAFI) that removes C-terminal lysines or arginines. The activity of active TAFI (TAFIa) is lost rapidly. TAFIa is not inactivated by proteolysis but converted to an inactive state by a conformational transition. Numerous polymorphisms were identified in the TAFI gene. The TAFI-325Ile variant seems to influence TAFI levels. TAFIa retards plasmin formation and makes plasmin more susceptible to inhibition by antiplasmin; it prevents the conversion of the fibrin fragment DD(E) to fragment DD that impairs fibrin polymerization. The complement-derived factors C3a and C5a as well as bradykinin are further substrates for TAFIa. Elevated TAFI levels were associated with an increased risk of venous thrombosis. TAFI deficiency has been shown to be associated with an enhanced leucocyte migration. The absence of TAFI results in delayed wound healing with disturbed keratinocyte migration. Pro-inflammatory properties of osteopontin are downregulated by TAFIa. Hence, TAFI plays a role – besides in regulation of fibrinolysis – in wound healing, angiogenesis, and inflammation.