This application seeks to improve basic understanding of molecular mechanisms that mediate cytoprotective actions of coagulation proteases on cells. Available therapeutic solutions for vascular, thrombotic, and inflammatory diseases are limited and mortality rates remain unacceptably high. Beneficial effects of activated protein C (APC) on cells contrast with proinflammatory effects of other coagulation proteases (e.g. thrombin and factor Xa) on cells and initiated novel perspectives on the intricate complex networks of receptor-mediated cross talk in cells. Improving therapeutic success requires a more thorough understanding of the molecular mechanisms involved. This proposal is centered on the endothelial protein C receptor (EPCR), a key cytoprotective receptor. The long-term objectives of this application are to contribute to diagnostic and therapeutic progress for vascular, thrombotic, and inflammatory diseases by advancing knowledge through both basic and translational research. The goal of this application is to gain novel insights into the molecular mechanisms of cytoprotective actions mediated by EPCR. The major focus of this application is on structure- function relationships for EPCR that underlie EPCR's cofactor role in the transduction of clinically relevant APC-mediated cytoprotective effects and on translation of this information into improved therapeutic strategies for thrombotic inflammatory diseases. Novel hypotheses will be tested using biochemical and cellular biology methods.
The specific aims are: 1) To generate engineered EPCR variants with unique properties that will enhance its ability to mediate cytoprotective effects, 2) To characterize the structure-function determinants for EPCR-dependent PAR-1 activation that are responsible for APC-mediated cytoprotective effects on cells, and 3) To define the thrombotic complications associated with "off-target" Heparin-Induced Thrombocytopenia (HIT) antibodies against PF4-EPCR and PF4-thrombomodulin (TM) complexes. Succesfull completion of the proposed studies will increase our knowledge and understanding of vascular, thrombotic, and inflammatory diseases and may provide a platform for the development of novel therapeutic strategies for a variety of disorders in which thrombosis, apoptosis and inflammation contribute to pathogenesis.

Public Health Relevance

Vascular, thrombotic, and inflammatory diseases, such as sepsis, heart attack or stroke, will affect most of us at some point in life, with a profound impact on the quality and duration of life thereafter. Available therapeutic solutions are limited and mortality rates remain unacceptably high. Guided by the encouraging beneficial effects of recombinant activated protein C in sepsis and stroke, the proposed studies will identify novel molecular mechanisms and create engineered molecular variants for translational research and potential safer and more effective therapeutic applications.

National Institute of Health (NIH)
National Heart, Lung, and Blood Institute (NHLBI)
Research Project (R01)
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Study Section
Hemostasis and Thrombosis Study Section (HT)
Program Officer
Link, Rebecca P
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Scripps Research Institute
La Jolla
United States
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von Drygalski, Annette; Bhat, Vikas; Gale, Andrew J et al. (2014) An engineered factor Va prevents bleeding induced by anticoagulant wt activated protein C. PLoS One 9:e104304
Aird, William C; Mosnier, Laurent O; Fairhurst, Rick M (2014) Plasmodium falciparum picks (on) EPCR. Blood 123:163-7
Mosnier, Laurent O (2014) PolyP and APC fight a RAGEing battle. Blood 123:804-6
Mosnier, Laurent O; Zlokovic, Berislav V; Griffin, John H (2014) Cytoprotective-selective activated protein C therapy for ischaemic stroke. Thromb Haemost 112:883-92
von Drygalski, A; Cramer, T J; Bhat, V et al. (2014) Improved hemostasis in hemophilia mice by means of an engineered factor Va mutant. J Thromb Haemost 12:363-72
Bouwens, E A M; Stavenuiter, F; Mosnier, L O (2013) Mechanisms of anticoagulant and cytoprotective actions of the protein C pathway. J Thromb Haemost 11 Suppl 1:242-53
von Drygalski, Annette; Furlan-Freguia, Christian; Ruf, Wolfram et al. (2013) Organ-specific protection against lipopolysaccharide-induced vascular leak is dependent on the endothelial protein C receptor. Arterioscler Thromb Vasc Biol 33:769-76
Wang, Yaoming; Sinha, Ranjeet Kumar; Mosnier, Laurent O et al. (2013) Neurotoxicity of the anticoagulant-selective E149A-activated protein C variant after focal ischemic stroke in mice. Blood Cells Mol Dis 51:104-8
Burnier, Laurent; Mosnier, Laurent O (2013) Novel mechanisms for activated protein C cytoprotective activities involving noncanonical activation of protease-activated receptor 3. Blood 122:807-16
Mosnier, L O; Fernandez, J A; Davis, T P et al. (2013) Influence of the 3K3A-activated protein C variant on the plasma clot lysis activity of t-PA and of t-PA on the variant's anticoagulant activity. J Thromb Haemost 11:2059-62

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