Table 2.

Antithrombotic factors expressed in normal vascular endothelium and its functional mechanisms.

Substance	Function		Antithrombotic Mechanism
TM	Modulator of thrombin activity Anticoagulation and anti-inflammation factor	Suppression of coagulation via protein C activation Enhancement of fibrinolysis via TAFI activation Inhibition of PAMPs/DAMPs and complement factors
Heparan sulfate	Activator of AT and TFPI	Suppression of coagulation via inhibition of thrombin, FXa, and FVIIa,
TFPI	Inhibitor of TF, FXa, and FVIIa	Suppression of coagulation initiation via inhibition of TF, FXa and FVIIa
Protein S	Activator of APC and TFPI	Enhancement of APC-mediated anticoagulation and TFPI-mediated anticoagulation
PGI2	Inhibitor of platelet activation	Inhibition of platelet activation
ecto-ATP/ADPase	Inhibitor of platelet activation	Inhibition of platelet activation
NO	Vasodilator	Inhibition of platelet activation and decrease of shear stress
t-PA	Activator of fibrinolysis	Activation of plasminogen to plasmin
IL-4	Anti-inflammatory cytokine	Inhibition of vascular endothelial inflammation
IL-10	Anti-inflammatory cytokine	Inhibition of vascular endothelial inflammation

TM, thrombomodulin; APC, activated protein C; TAFI, thrombin-activated fibrinolysis inhibitor; PAMPs, pathogen-associated molecular patterns; DAMPs, damage-associated molecular patterns; AT, antithrombin; TFPI, tissue factor pathway inhibitor; NO, nitric oxide; PGI₂, prostacyclin; t-PA, tissue plasminogen activator; IL-4, interleukin-4; IL-10, interleukin-10.