Protein C and protein S deficiencies contribute to morbidity and mortality in men and mice. Recombinant acfivated 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 collaborafions 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 acfivation of the PI3K-Akt survival pathway. Engineering of murine APC and apoER2 mutants will allow interrogation ofthe protein surfaces that mediate binding and signal inifiation by APC:apoER2 interactions and will provide reagents for in vivo proof of principle studies for mechanisms of APCs acfion in murine sepsis. Studies of mice genefically modified in apoER2 and Dabi will establish whether apoER2 and Dabi mediate APCs mortality reducfion acfivities in sepsis. Protein S deficient mice will be subjected to thrombofic provocafion and treated with combinations of recombinant wild type and mutant murine protein S and APC or other agents to define the relafive 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 diagnosfic or therapeufic advances involving the protein C and protein S systems.

Public Health Relevance

Protein C or protein S deficiency contributes to excessive blood clotting. Recombinant acfivated 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 genefically modified. Novel principles that are established by these preclinical animal model studies may ulfimately be translated into diagnosfic or therapeutic advances involving the protein C and protein S systems.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Program Projects (P01)
Project #
2P01HL031950-26A1
Application #
8191407
Study Section
Heart, Lung, and Blood Initial Review Group (HLBP)
Project Start
Project End
Budget Start
2011-07-01
Budget End
2012-06-30
Support Year
26
Fiscal Year
2011
Total Cost
$419,395
Indirect Cost
Name
Scripps Research Institute
Department
Type
DUNS #
781613492
City
La Jolla
State
CA
Country
United States
Zip Code
92037
Klann, Jane E; Kim, Stephanie H; Remedios, Kelly A et al. (2018) Integrin Activation Controls Regulatory T Cell-Mediated Peripheral Tolerance. J Immunol 200:4012-4023
Griffin, John H; Zlokovic, Berislav V; Mosnier, Laurent O (2018) Activated protein C, protease activated receptor 1, and neuroprotection. Blood 132:159-169
Sinha, Ranjeet K; Wang, Yaoming; Zhao, Zhen et al. (2018) PAR1 biased signaling is required for activated protein C in vivo benefits in sepsis and stroke. Blood 131:1163-1171
Xu, Xiaohong Ruby; Wang, Yiming; Adili, Reheman et al. (2018) Apolipoprotein A-IV binds ?IIb?3 integrin and inhibits thrombosis. Nat Commun 9:3608
Gupta, Naveen; Liu, Roland; Shin, Stephanie et al. (2018) SCH79797 improves outcomes in experimental bacterial pneumonia by boosting neutrophil killing and direct antibiotic activity. J Antimicrob Chemother 73:1586-1594
Gupta, Naveen; Sinha, Ranjeet; Krasnodembskaya, Anna et al. (2018) The TLR4-PAR1 Axis Regulates Bone Marrow Mesenchymal Stromal Cell Survival and Therapeutic Capacity in Experimental Bacterial Pneumonia. Stem Cells 36:796-806
Amar, Arun Paul; Sagare, Abhay P; Zhao, Zhen et al. (2018) Can adjunctive therapies augment the efficacy of endovascular thrombolysis? A potential role for activated protein C. Neuropharmacology 134:293-301
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
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
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

Showing the most recent 10 out of 428 publications