The main objective of these studies is to continue study of the influence of protein S and C4b-binding protein on the disseminated intravascular coagulant response in the lethal E.coli model of sepsis. Since these two factors also influence microvascular thrombotic and deep vein thrombotic responses to inflammatory stimuli, we plan to study the role of these two factors in these models as well. The central hypotheses is that protein S has two protective functions. The first is as an anticoagulant cofactor for activated protein C and the second is as an anticomplement cofactor for C4b-binding protein. Conversely, insufficiency of protein S relative to C4bBP can lead to an amplification of both the inflammatory and coagulant responses because they are linked and drive each other. Thus reduction of protein S by consumption or by neutralization by excess C4bBP can leave pro-inflammatory as well as procoagulant activity unchecked unless there is sufficient protein S to serve both its anticomplement and anticoagulant functions. Certain aspects of this hypothesis can be tested in vivo. Using the model of disseminated intravascular coagulant response to lethal E.coli we will intervene with C4bBP/protein S complex or protein S and monitor their effects on physiologic and laboratory parameters. These include C5b-9 and C4bc markers of complement system activation, thrombin-antithrombin complexes and fibrinogen markers of coagulant activation as well as cytokine and components of the protein C pathway (ie. free and bound protein S, protein C and C4bBP). We will determine if there is a pool of C4bBP/protein S complex bound to cell membranes with antibodies to the Gla domain of protein S by which these complexes might be anchored. We will monitor this by assaying for increases of the complex in plasma following infusion of antibodies. We also will study recruitment of radiolabeled complexes to these membranes before and after an inflammatory stimulus (ie. E.coli, TNF). We will study which domains of protein S participate with the appropriate antibodies. We will intervene with anti-C3b antibody and compare its anti -complement effects with those of the C4bBP/protein S complex. Using the models of the microvascular thrombotic response to sublethal E.coli and C4bBP and the deep vein thrombotic response to TNF and C4bBP, we will probe some of the same systems described above as well as features unique to each model. We will examine the role of tissue factor and platelets in the former and that of tissue factor and leukocytes in the latter. To give these studies more perspective, the pathologic responses of these two models will be divided into stages. This includes correlation of laboratory markers with light and electron microscopic studies of tissue. These studies should provide insights into the relationship between inflammation and coagulation in E.coli sepsis and offer new perspectives on diagnosis and treatment.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
2R01GM037704-07
Application #
3293269
Study Section
Hematology Subcommittee 2 (HEM)
Project Start
1986-12-01
Project End
1995-11-30
Budget Start
1992-12-01
Budget End
1993-11-30
Support Year
7
Fiscal Year
1993
Total Cost
Indirect Cost
Name
Oklahoma Medical Research Foundation
Department
Type
DUNS #
937727907
City
Oklahoma City
State
OK
Country
United States
Zip Code
73104
Taylor Jr, Fletcher B; Kinasewitz, Gary T; Lupu, Florea (2012) Pathophysiology, staging and therapy of severe sepsis in baboon models. J Cell Mol Med 16:672-82
Lupu, Cristina; Zhu, Hua; Popescu, Narcis I et al. (2011) Novel protein ADTRP regulates TFPI expression and function in human endothelial cells in normal conditions and in response to androgen. Blood 118:4463-71
Popescu, Narcis I; Lupu, Cristina; Lupu, Florea (2010) Extracellular protein disulfide isomerase regulates coagulation on endothelial cells through modulation of phosphatidylserine exposure. Blood 116:993-1001
Popescu, Narcis I; Lupu, Cristina; Lupu, Florea (2010) Role of PDI in regulating tissue factor: FVIIa activity. Thromb Res 125 Suppl 1:S38-41
Silasi-Mansat, Robert; Zhu, Hua; Popescu, Narcis I et al. (2010) Complement inhibition decreases the procoagulant response and confers organ protection in a baboon model of Escherichia coli sepsis. Blood 116:1002-10
Xu, Jun; Zhang, Xiaomei; Pelayo, Rosana et al. (2009) Extracellular histones are major mediators of death in sepsis. Nat Med 15:1318-21
Samis, J A; Stewart, K A; Nesheim, M E et al. (2009) Time-dependent association between coagulation factor inactivation and increased elastase during experimental sepsis. J Thromb Haemost 7:1032-4
Fu, Jianxin; Gerhardt, Holger; McDaniel, J Michael et al. (2008) Endothelial cell O-glycan deficiency causes blood/lymphatic misconnections and consequent fatty liver disease in mice. J Clin Invest 118:3725-37
Aragones, Julian; Schneider, Martin; Van Geyte, Katie et al. (2008) Deficiency or inhibition of oxygen sensor Phd1 induces hypoxia tolerance by reprogramming basal metabolism. Nat Genet 40:170-80
Tang, Haiwang; Ivanciu, Lacramioara; Popescu, Narcis et al. (2007) Sepsis-induced coagulation in the baboon lung is associated with decreased tissue factor pathway inhibitor. Am J Pathol 171:1066-77

Showing the most recent 10 out of 42 publications