Activated protein C: a promising drug with multiple effects?

The anti-coagulant activated protein C (APC) can exert direct effects on cells, including cytoprotective functions involving apoptosis and inflammation mechanisms. These cytoprotective properties of APC require the presence of protease-activated receptor-1 (PAR-1) and endothelial protein C receptor (EPCR) resulting in inhibition of inflammatory gene expression and down-regulation of p53 and Bax. Several in vitro and animal studies have documented such cytoprotective properties of APC. The first evidence for a cytoprotective role of APC in a clinical setting came from the PROWESS trial in which APC administration reduced mortality rates in severe sepsis patients. However, although APC certainly has the potential to be used in a broader range of clinical settings it is thwarted by the associated risk of bleeding. Further research within this area towards improved therapeutics of specific APC mutants has taken place.