Thromb Haemost 2010; 103(06): 1239-1244
DOI: 10.1160/TH09-11-0750
Blood Coagulation, Fibrinolysis and Cellular Haemostasis
Schattauer GmbH

Blocking endothelial protein C receptor (EPCR) accelerates thrombus development in vivo

Miguel N. Centelles
1   Division of Cardiovascular Sciences, Laboratory of Thrombosis and Haemostasis, Centre for Applied Medical Research, University of Navarra, Pamplona, Spain
,
Cristina Puy
1   Division of Cardiovascular Sciences, Laboratory of Thrombosis and Haemostasis, Centre for Applied Medical Research, University of Navarra, Pamplona, Spain
,
Jacinto Lopez-Sagaseta
1   Division of Cardiovascular Sciences, Laboratory of Thrombosis and Haemostasis, Centre for Applied Medical Research, University of Navarra, Pamplona, Spain
,
Kenji Fukudome
2   Department of Immunology, Saga Medical School, Saga, Japan
,
Ramón Montes
1   Division of Cardiovascular Sciences, Laboratory of Thrombosis and Haemostasis, Centre for Applied Medical Research, University of Navarra, Pamplona, Spain
,
José Hermida
1   Division of Cardiovascular Sciences, Laboratory of Thrombosis and Haemostasis, Centre for Applied Medical Research, University of Navarra, Pamplona, Spain
› Institutsangaben

Financial support: This work was supported through the Unión Temporal de Empresas project CIMA and by grants from Instituto de Salud Carlos III (PI051178, Red Temática de Investigación RECAVA RD/0014/0008). Jacinto López Sagaseta was supported by a fellowship from the Education Department, Gobierno de Navarra.
Weitere Informationen

Publikationsverlauf

Received: 05. November 2009

Accepted after major revision: 01. Februar 2010

Publikationsdatum:
22. November 2017 (online)

Preview

Summary

The endothelial protein C receptor (EPCR) plays an anticoagulant role by improving protein C activation. Although low levels of activated protein C (APC) constitute a thrombosis risk factor, the relationship between modulating EPCR function and thrombosis has not been addressed so far. Monoclonal antibodies (mAb) against murine EPCR were raised, and their ability to block protein C/APC binding was tested. The ferric chloride carotid artery injury model in mice was chosen to test the effect of anti-EPCR mAb on thrombus formation. The time to total occlusion of the vessel was analysed in three groups, given an isotype control mAb (IC), a blocking (RCR-16) or a non-blocking (RCR-20) anti-EPCR mAb. RCR-16 prevented the interaction between protein C/APC and EPCR as demonstrated by surface plasmon resonance and flow cytometry, and inhibited the activation of protein C on the endothelium. IC and RCR-20 were unable to induce such effects. In vivo, RCR-16 shortened the time to total vessel occlusion with respect to IC [13.4 ± 1.0 (mean ± SD) and 17.8 ± 3.2 minutes, respectively, p<0.001]. Occlusive thrombi lasting for more than one hour were observed in all RCR-16-treated animals, but only in 43% of IC-treated ones. Results with RCR-20 were indistinguishable from those observed with IC. For the first time, a direct relationship between blocking EPCR and thrombosis is demonstrated. Blocking anti-EPCR autoantibodies can predispose to thrombosis episodes and may constitute a new therapeutic target.