The long-term objective of this research program is to define the mechanisms by which the central hemostatic protease, thrombin, contributes to the development of sickle cell disease (SCD) pathologies. The seminal role of thrombin in hemostasis and vascular biology is underscored by the fact that this protease positively controls fibrin deposition, platelet activation, and endothelial cell (EC) signaling events via multiple substrates and receptors [e.g., protease-activated receptors, fibrinogen, factor XI, and factor XIII], as well as negatively controls further thrombin generation through the activation of protein C, a natural anticoagulant with known anti-inflammatory/cytoprotective properties. The control of thrombin activity has been intensely studied because thrombin-mediated proteolysis is fundamental to both physiological hemostasis and pathological vaso-occlusive events, including myocardial infarction, venous thrombosis and stroke. However, an additional driving force for detailed studies of thrombin and thrombin targets is that these proteins also control vascular permeability/barrier function, tissue repair, and inflammation, which together contribute to the development of multiple inflammatory diseases. Given that circulating sickle cells result in a combination of vascular damage, occlusive events and inflammatory changes, and given that local and systemic hemostatic system activation is a conspicuous feature of SCD, thrombin and thrombin targets are prime candidates to be clinically-significant modifiers of sickle cell disease pathobiology.
The aims of this project center on two general hypotheses: i) thrombin, as a master regulator of vascular biology, platelet/EC activation, fibrin deposition and inflammatory processes, is a major determinant of SCD pathologies, and ii) SCD-associated morbidities can be ameliorated by novel genetic or pharmacological interventions at the level of pro/thrombin and downstream thrombin substrates. These hypotheses will be tested through studies that focus on defining the importance of prothrombin in the development of multi-organ SCD pathologies and long-term survival in Berkeley sickle mice (Hba0/Hbb0 [Tg(Human HbS)]+/+) (Aim 1);understanding the thrombin-mediated, fibrin(ogen)-dependent and fibrin(ogen)-independent mechanisms driving SCD pathologies (Aim 2);and establishing the potential benefit of thrombin-targeted pharmacological intervention in limiting SCD pathologies in mice (Aim 3). The proposed studies will provide for the first time a clear understanding of the significance of hemostatic factors in the pathogenesis of SCD and may illuminate novel therapeutic strategies for limiting SCD-induced morbidities.

Public Health Relevance

Sickle cell anemia affects over 100,000 Americans and millions worldwide and results in occlusion of blood vessels, pain crises, inflammation, damage to multiple organs, stroke and reduced life-expectancy. There is substantial evidence of coagulation ('clotting') factor activation in sickle cell patients;however, the precise contribution of coagulation factors to vessel occlusion and inflammation remains unclear. The primary goal of this research is to use modern molecular genetics to develop an in-depth understanding of the contribution of key coagulation factors in sickle cell disease and explore novel treatment strategies for patients with this disease.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL112603-03
Application #
8585089
Study Section
Special Emphasis Panel (ZRG1-VH-D (03))
Program Officer
Kindzelski, Andrei L
Project Start
2012-01-01
Project End
2016-11-30
Budget Start
2013-12-01
Budget End
2014-11-30
Support Year
3
Fiscal Year
2014
Total Cost
$344,250
Indirect Cost
$119,250
Name
Cincinnati Children's Hospital Medical Center
Department
Type
DUNS #
071284913
City
Cincinnati
State
OH
Country
United States
Zip Code
45229
Kattula, Sravya; Byrnes, James R; Martin, Sara M et al. (2018) Factor XIII in plasma, but not in platelets, mediates red blood cell retention in clots and venous thrombus size in mice. Blood Adv 2:25-35
Stagaard, Rikke; Ley, Carsten Dan; Almholt, Kasper et al. (2018) Absence of functional compensation between coagulation factor VIII and plasminogen in double-knockout mice. Blood Adv 2:3126-3136
Shaw, Maureen A; Gao, Zhen; McElhinney, Kathryn E et al. (2017) Plasminogen Deficiency Delays the Onset and Protects from Demyelination and Paralysis in Autoimmune Neuroinflammatory Disease. J Neurosci 37:3776-3788
Flick, M J; Bugge, T H (2017) Plasminogen-receptor KT : plasminogen activation and beyond. J Thromb Haemost 15:150-154
Kopec, Anna K; Abrahams, Sara R; Thornton, Sherry et al. (2017) Thrombin promotes diet-induced obesity through fibrin-driven inflammation. J Clin Invest 127:3152-3166
Ko, Ya-Ping; Flick, Matthew J (2016) Fibrinogen Is at the Interface of Host Defense and Pathogen Virulence in Staphylococcus aureus Infection. Semin Thromb Hemost 42:408-21
Byrnes, James R; Wilson, Clare; Boutelle, Anthony M et al. (2016) The interaction between fibrinogen and zymogen FXIII-A2B2 is mediated by fibrinogen residues ?390-396 and the FXIII-B subunits. Blood 128:1969-1978
Niss, Omar; Quinn, Charles T; Lane, Adam et al. (2016) Cardiomyopathy With Restrictive Physiology in Sickle Cell Disease. JACC Cardiovasc Imaging 9:243-52
Bakeer, Nihal; James, Jeanne; Roy, Swarnava et al. (2016) Sickle cell anemia mice develop a unique cardiomyopathy with restrictive physiology. Proc Natl Acad Sci U S A 113:E5182-91
Prasad, Joni M; Gorkun, Oleg V; Raghu, Harini et al. (2015) Mice expressing a mutant form of fibrinogen that cannot support fibrin formation exhibit compromised antimicrobial host defense. Blood 126:2047-58

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