Protein C and protein S deficiencies contribute to morbidity and mortality in men and mice. Recombinant activated protein C (APC) therapy reduces mortality in adult severe sepsis patients. There is a major need for new insights into the physiologic and pharmacologic mechanisms of action of APC and protein S. To establish in vivo proof of principle for such mechanisms. Project 1 uses genetically modified mice, murine injury models, and novel recombinant murine proteins and involves extensive collaborations with Drs. Ruggeri and Ruf APC exerts two distinct activities: (1) anticoagulant activity and (2) direct beneficial effects on cells comprising a variety of cytoprotective actions. This latter activity is critical for mortality reduction by APC in murine sepsis models. The current paradigm for APCs cell signaling involves binding of APC by endothelial protein C receptor (EPCR) combined with protease activated receptor-1 (PARI) proteolytic activation. We found that there is another signaling pathway initiated by APC that involves ligation of apolipoprotein E Receptor 2 (apoER2), signaling via the adaptor protein. Dabi, and Src-family kinases with downstream activation of the PI3K-Akt survival pathway. Engineering of murine APC and apoER2 mutants will allow interrogation ofthe protein surfaces that mediate binding and signal initiation by APC:apoER2 interactions and will provide reagents for in vivo proof of principle studies for mechanisms of APCs action in murine sepsis. Studies of mice genetically modified in apoER2 and Dab1 will establish whether apoER2 and Dab1 mediate APCs mortality reduction activities in sepsis. Protein S deficient mice will be subjected to thrombotic provocation and treated with combinations of recombinant wild type and mutant murine protein S and APC or other agents to define the relative efficacies for protein S antithrombotic activity that is either dependent on APC or independent of APC. Novel Principles that are established by these preclinical animal model studies may ultimately be translated into diagnostic or therapeutic advances involving the protein C and protein S systems.

Public Health Relevance

Protein C or protein S deficiency contributes to excessive blood clotting. Recombinant activated protein C (APC) is FDA-approved for reducing death in adult severe sepsis, but we don't understand how this drug works. To gain new insights, we will use engineered APC and protein S plus mice that are genetically modified. Novel principles that are established by these preclinical animal model studies may ultimately be translated into diagnostic or therapeutic advances involving the protein C and protein S systems.

National Institute of Health (NIH)
National Heart, Lung, and Blood Institute (NHLBI)
Research Program Projects (P01)
Project #
Application #
Study Section
Heart, Lung, and Blood Initial Review Group (HLBP)
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
Scripps Research Institute
La Jolla
United States
Zip Code
Subramaniam, Saravanan; Jurk, Kerstin; Hobohm, Lukas et al. (2017) Distinct contributions of complement factors to platelet activation and fibrin formation in venous thrombus development. Blood 129:2291-2302
Kamikubo, Yuichi; Mendolicchio, G Loredana; Zampolli, Antonella et al. (2017) Selective factor VIII activation by the tissue factor-factor VIIa-factor Xa complex. Blood 130:1661-1670
Amar, Arun Paul; Sagare, Abhay P; Zhao, Zhen et al. (2017) Can adjunctive therapies augment the efficacy of endovascular thrombolysis? A potential role for activated protein C. Neuropharmacology :
Klann, Jane E; Remedios, Kelly A; Kim, Stephanie H et al. (2017) Talin Plays a Critical Role in the Maintenance of the Regulatory T Cell Pool. J Immunol 198:4639-4651
Rothmeier, Andrea S; Marchese, Patrizia; Langer, Florian et al. (2017) Tissue Factor Prothrombotic Activity Is Regulated by Integrin-arf6 Trafficking. Arterioscler Thromb Vasc Biol 37:1323-1331
Deguchi, Hiroshi; Navarro, Silvia; Payne, Amanda B et al. (2017) Low level of the plasma sphingolipid, glucosylceramide, is associated with thrombotic diseases. Res Pract Thromb Haemost 1:33-40
Alsultan, Abdulrahman; Gale, Andrew J; Kurban, Kadijah et al. (2016) Activation-resistant homozygous protein C R229W mutation causing familial perinatal intracranial hemorrhage and delayed onset of thrombosis. Thromb Res 143:17-21
Ruf, Wolfram; Rothmeier, Andrea S; Graf, Claudine (2016) Targeting clotting proteins in cancer therapy - progress and challenges. Thromb Res 140 Suppl 1:S1-7
Bhat, Vikas; von Drygalski, Annette; Gale, Andrew J et al. (2016) Improved coagulation and haemostasis in haemophilia with inhibitors by combinations of superFactor Va and Factor VIIa. Thromb Haemost 115:551-61
Abplanalp, Wesley T; Conklin, Daniel J; Cantor, Joseph M et al. (2016) Enhanced Integrin ?4?1-Mediated Adhesion Contributes to a Mobilization Defect of Endothelial Progenitor Cells in Diabetes. Diabetes 65:3505-3515

Showing the most recent 10 out of 422 publications