OVERALL OBJECTIVES: These are (1) to obtain sufficient information about the fibrinolytic cascade to summarize and describe it by a computer model, and (2) to determine the role of the enzyme TAFIa in down regulating the fibrinolytic cascade and connecting the fibrinolytic and coagulation cascades. BACKGROUND AND SIGNIFICANCE: The fibrinolytic cascade removes inappropriately deposited fibrin and assures an unimpeded flow of blood in the vascular system. Although many of the features of the cascade have been elucidated, many quantitative details are lacking. In addition, a new potential connection between the coagulation and fibrinolytic cascades is suggested by the discovery of TAFI (Thrombin Activatable Fibrinolytic Inhibitor). These studies should provide new information on the basic properties of the fibrinolytic cascade, its connection to coagulation, and its regulation. These studies also should provide new rationale for improving thrombolytic therapy.
SPECIFIC AIMS : (1) to determine the antifibrinolytic mechanism of TAFIa and its potential to modulate coagulation. (2) to study fibrin-dependent plasminogen activation with fluorescently labelled (S741C) plasminogen. (3) to investigate the enzymology of plasmin-catalyzed fibrin degradation. (4) to study the role of platelets in plasminogen activation and fibrinolysis. (5) to continue to develop the Lys-Speed computer model of the fibrinolytic cascade. METHODS OF PROCEDURE: The effects of TAFIa will be studied by exposing purified components to TAFIa and determining their loss of COOH Arg or Lys and quantifying their changes in functional properties. Plasminogen activation in fibrin will be measured by the fluorescence change that occurs when the plasminogen derivative is cleaved. Fibrin breakdown will be studied by perfusing fibrin with plasmin, capturing the solubilized material in a plasmin inhibitor, and analyzing released material with respect to concentration, size, protomer, and chain composition. Washed platelets and purified components will be used to determine the role of platelets in modulating plasminogen and TAFI activation, tPA inhibition, and fibrin breakdown. The computer model will be developed by incorporating new parameter values and mechanistic equations obtained from work carried out to satisfy the first four specific aims.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Program Projects (P01)
Project #
5P01HL046703-09
Application #
6202326
Study Section
Project Start
1999-09-29
Project End
2000-08-31
Budget Start
1997-10-01
Budget End
1998-09-30
Support Year
9
Fiscal Year
1999
Total Cost
Indirect Cost
Name
University of Vermont & St Agric College
Department
Type
DUNS #
066811191
City
Burlington
State
VT
Country
United States
Zip Code
05405
Kusak, Piotr; Czarnecka, Danuta; Gissel, Matthew et al. (2016) Activated factor IX, factor XI and tissue factor identify patients with permanent atrial fibrillation treated with warfarin who are at risk of ischemic stroke. Arch Med Sci 12:1000-1007
Bouchard, Beth A; Chapin, John; Brummel-Ziedins, Kathleen E et al. (2015) Platelets and platelet-derived factor Va confer hemostatic competence in complete factor V deficiency. Blood 125:3647-50
Brummel-Ziedins, Kathleen E; Everse, Stephen J; Mann, Kenneth G et al. (2014) Modeling thrombin generation: plasma composition based approach. J Thromb Thrombolysis 37:32-44
Bouchard, Beth A; Gissel, Matthew T; Whelihan, Matthew F et al. (2014) Platelets do not express the oxidized or reduced forms of tissue factor. Biochim Biophys Acta 1840:1188-93
de Haan, Hugoline G; Bezemer, Irene D; Vossen, Carla Y et al. (2014) Genetic variants in Cell Adhesion Molecule 1 (CADM1): a validation study of a novel endothelial cell venous thrombosis risk factor. Thromb Res 134:1186-92
Undas, A; Brummel-Ziedins, K E; Mann, K G (2014) Anticoagulant effects of statins and their clinical implications. Thromb Haemost 111:392-400
Whelihan, Matthew F; Kiankhooy, Armin; Brummel-Ziedins, Kathleen E (2014) Thrombin generation and fibrin clot formation under hypothermic conditions: an in vitro evaluation of tissue factor initiated whole blood coagulation. J Crit Care 29:24-30
Krudysz-Amblo, Jolanta; Jennings 2nd, Mark E; Knight, Tyler et al. (2013) Disulfide reduction abolishes tissue factor cofactor function. Biochim Biophys Acta 1830:3489-96
Ayombil, F; Abdalla, S; Tracy, P B et al. (2013) Proteolysis of plasma-derived factor V following its endocytosis by megakaryocytes forms the platelet-derived factor V/Va pool. J Thromb Haemost 11:1532-9
Baker, Jason V; Brummel-Ziedins, Kathleen; Neuhaus, Jacqueline et al. (2013) HIV replication alters the composition of extrinsic pathway coagulation factors and increases thrombin generation. J Am Heart Assoc 2:e000264

Showing the most recent 10 out of 247 publications