Figure 2.

Illustration of the potential multiple effects of inhaled activated protein C (iAPC) in ARDS in relation to the underlying pathophysiology of ARDS. Inhaled APC (1) inhibits coagulation (Factor Va and VIIIa) (2) and enhances fibrinolysis (3). Further iAPC has an anti-inflammatory effect and anti-apoptotic effect exerted via its APC receptor (EPCR) on the alveolar macrophage, epithelial cell and finally at the site of small airways (4) and reduces tissue factor expression via inhibition of the transnuclear NFKB translocation (5). Finally iAPC inhibits neutrocyte recruitment from the circulation to the airspaces (6) without interfering with their host function. The numbers 1–6 refer to the multiple points of action of iAPC.

Abbreviations: AF, Alveolar macrophage; EPCR, Epithelial protein C receptor; FVII, Coagulation factor VII; SA cell, Mucosal cell of small airways.