. Atherosclerotic cardiovascular disease remains the leading cause of death in our society. The development of atherosclerotic lesions fits the model of chronic inflammation in response to injury. Because the interior of the atherosclerotic lesion is separated from the vessel lumen, there is an extravascular inflammatory microenvironment therein. Monocytes are essential participants in both the initiation and evolution of these lesions, which are also marked by the presence of fibrin. Monocytes exposed to inflammatory stimuli such as LPS rapidly produce high levels of Plasminogen Activator Inhibitor Type 2 (PA-2), a molecule that fosters an antifibrinolytic microenvironment and allows for the persistence and maturation of fibrin deposits. Tumor necrosis factor (TNF), also produced by stimulated monocytes, may, in an autocrine manner, induce these cells to produce high levels of PAI-2 over long periods of time. PAI-2 is not inactivated by the oxidative mediators present at an inflammatory site as would be PAI-1, and PAI-2 (but not PAI-1) is produced by monocytes within the inflammatory focus, so changes in its production can be rapid and in direct response to changes in the immediate local situation. PAI-2 protein production is directly related to levels of PAI-2 mRNA, which are controlled to some extent by inducible changes in their rate of degradation. In some, although PAI-2 seems important in maintaining the anti-fibrinolytic environment of extravascular inflammatory lesions, little is known about the physiological regulation of its production. In this application we therefore propose to: (1) Determine the role of TNF in stimulating a sustained increase in monocyte production of PAI-2; (2) Determine the intracellular signalling mechanisms operative in the monocyte PAI-2 responses to LPS and TNF (i.e., does any stimulus which increases PAI-2 production trigger the same intracellular signals, or can different stimuli cause activation of different intracellular messages and yet induce the same response?); (3) Determine whether changes in mRNA stability play a significant role in regulating monocyte production of PAI-2, and if so whether the above intracellular signalling pathways have a role in determining such changes in mRNA stability.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL043506-09
Application #
2221056
Study Section
Hematology Subcommittee 2 (HEM)
Project Start
1983-08-01
Project End
1995-03-31
Budget Start
1993-04-01
Budget End
1995-03-31
Support Year
9
Fiscal Year
1993
Total Cost
Indirect Cost
Name
University of Wisconsin Madison
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
161202122
City
Madison
State
WI
Country
United States
Zip Code
53715
Li, Shih-Hon; Gorlatova, Natalia V; Lawrence, Daniel A et al. (2008) Structural differences between active forms of plasminogen activator inhibitor type 1 revealed by conformationally sensitive ligands. J Biol Chem 283:18147-57
Barker-Carlson, Karen; Lawrence, Daniel A; Schwartz, Bradford S (2002) Acyl-enzyme complexes between tissue-type plasminogen activator and neuroserpin are short-lived in vitro. J Biol Chem 277:46852-7
Schwartz, B S; Espana, F (1999) Two distinct urokinase-serpin interactions regulate the initiation of cell surface-associated plasminogen activation. J Biol Chem 274:15278-83
Lumelsky, N L; Schwartz, B S (1997) Protein kinase C in erythroid and megakaryocytic differentiation: possible role in lineage determination. Biochim Biophys Acta 1358:79-92
Lumelsky, N L; Schwartz, B S (1996) Protease inhibitors induce specific changes in protein tyrosine phosphorylation that correlate with inhibition of apoptosis in myeloid cells. Cancer Res 56:3909-14
Goldman, I L; Kopelberg, M; Debaene, J E et al. (1996) Antiplatelet activity in onion (Allium cepa) is sulfur dependent. Thromb Haemost 76:450-2
Manchanda, N; Schwartz, B S (1995) Interaction of single-chain urokinase and plasminogen activator inhibitor type 1. J Biol Chem 270:20032-5
Schwartz, B S (1994) Differential inhibition of soluble and cell surface receptor-bound single-chain urokinase by plasminogen activator inhibitor type 2. A potential regulatory mechanism. J Biol Chem 269:8319-23
Schwartz, B S; Bradshaw, J D (1992) Regulation of plasminogen activator inhibitor mRNA levels in lipopolysaccharide-stimulated human monocytes. Correlation with production of the protein. J Biol Chem 267:7089-94
Manchanda, N; Schwartz, B S (1991) Single chain urokinase. Augmentation of enzymatic activity upon binding to monocytes. J Biol Chem 266:14580-4