Deep venous thrombosis (DVT) is a significant clinical problem that can also lead to potentially fatal pulmonary embolism. Clinical studies reveal that thrombus resolution is central to the pathogenesis of post- thrombotic syndrome. Mechanisms that lead to thrombus resolution in DVT are not well understood at this time. It is clear, however, that optimal resolution of the thrombus requires an inflammatory response in which neutrophil and macrophages are recruited to the thrombus, and require proteases to degrade the matrix and thrombus. Our preliminary data employing mouse models of DVT reveal that genetic deletion of the LDLr results in enhanced thrombus resolution in mouse models of DVT. This appears to result from early recruitment of macrophages into the lesion in LDLr-deficient mice. This is accompanied by increased expression of MMP2;a protease implicated in thrombus resolution and decreased expression of PAI-1 in the thrombus isolated from LDLr-deficient mice. Further, we discovered that mice in which the LRP1 gene has been selectively deleted in macrophages also demonstrate enhanced thrombus resolution in a model of deep vein thrombosis. The central hypothesis of this application is that certain LDL receptor family members play important roles in modulating inflammatory events and protease activity thereby regulating clot resolution in mouse models of Deep Vein Thrombosis (DVT). The specific hypotheses to be tested are: 1) that the LDLr modulates thrombus resolution during DVT by modulating inflammation;2) that LRP1 modulate thrombus resolution by regulating protease levels and by regulating signaling events in inflammation and 3) that we can engineer inhibitor molecules for receptor blockade that would enhance thrombus resolution in DVT. These hypotheses will be tested in the following specific aims: 1) Determine mechanisms by which the LDLr regulates thrombus resolution in mouse models of DVT;2) Define the mechanisms by which LRP1 expressed in macrophages modulates thrombus resolution in mouse models of DVT and 3) Develop strategies for receptor blockade by designing antagonists for LDLR and LRP1 to enhance thrombus resolution in DVT.

Public Health Relevance

Deep vein thrombosis (DVT) and resulting pulmonary embolism represents a significant clinical problem. Clinical studies reveal that rapid resolution o the thrombus is a critical factor for patient outcomes. Those patients whose thrombus resolves slowly often experience damage to the veins. We have discovered two new molecules, the LDL receptor and LRP1 that modulate thrombus resolution in mouse models. These studies will identify new mechanisms that modulate this process, and will allow us to develop new strategies for potential therapeutic intervention in this disease.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL114379-02
Application #
8435382
Study Section
Special Emphasis Panel (ZRG1-VH-J (02))
Program Officer
Kindzelski, Andrei L
Project Start
2012-03-01
Project End
2017-02-28
Budget Start
2013-03-01
Budget End
2014-02-28
Support Year
2
Fiscal Year
2013
Total Cost
$365,330
Indirect Cost
$127,330
Name
University of Maryland Baltimore
Department
Surgery
Type
Schools of Medicine
DUNS #
188435911
City
Baltimore
State
MD
Country
United States
Zip Code
21201
Doherty, Christine M; Visse, Robert; Dinakarpandian, Deendayal et al. (2016) Engineered Tissue Inhibitor of Metalloproteinases-3 Variants Resistant to Endocytosis Have Prolonged Chondroprotective Activity. J Biol Chem 291:22160-22172
Noyes, Nathaniel C; Hampton, Brian; Migliorini, Mary et al. (2016) Regulation of Itch and Nedd4 E3 Ligase Activity and Degradation by LRAD3. Biochemistry 55:1204-13
Strickland, Dudley K; Muratoglu, Selen C (2016) LRP in Endothelial Cells: A Little Goes a Long Way. Arterioscler Thromb Vasc Biol 36:213-6
Young, Patricia A; Migliorini, Mary; Strickland, Dudley K (2016) Evidence That Factor VIII Forms a Bivalent Complex with the Low Density Lipoprotein (LDL) Receptor-related Protein 1 (LRP1): IDENTIFICATION OF CLUSTER IV ON LRP1 AS THE MAJOR BINDING SITE. J Biol Chem 291:26035-26044
Yamamoto, Kazuhiro; Okano, Hiroshi; Miyagawa, Wakako et al. (2016) MMP-13 is constitutively produced in human chondrocytes and co-endocytosed with ADAMTS-5 and TIMP-3 by the endocytic receptor LRP1. Matrix Biol 56:57-73
Yakovlev, Sergiy; Belkin, Alexey M; Chen, Ling et al. (2016) Anti-VLDL receptor monoclonal antibodies inhibit fibrin-VLDL receptor interaction and reduce fibrin-dependent leukocyte transmigration. Thromb Haemost 116:1122-1130
Prasad, Joni M; Young, Patricia A; Strickland, Dudley K (2016) High Affinity Binding of the Receptor-associated Protein D1D2 Domains with the Low Density Lipoprotein Receptor-related Protein (LRP1) Involves Bivalent Complex Formation: CRITICAL ROLES OF LYSINES 60 AND 191. J Biol Chem 291:18430-9
Prasad, Joni M; Migliorini, Mary; Galisteo, Rebeca et al. (2015) Generation of a Potent Low Density Lipoprotein Receptor-related Protein 1 (LRP1) Antagonist by Engineering a Stable Form of the Receptor-associated Protein (RAP) D3 Domain. J Biol Chem 290:17262-8
Kang, Liang-I; Isse, Kumiko; Koral, Kelly et al. (2015) Tissue-type plasminogen activator suppresses activated stellate cells through low-density lipoprotein receptor-related protein 1. Lab Invest 95:1117-29
Davis, Frank M; Rateri, Debra L; Balakrishnan, Anju et al. (2015) Smooth muscle cell deletion of low-density lipoprotein receptor-related protein 1 augments angiotensin II-induced superior mesenteric arterial and ascending aortic aneurysms. Arterioscler Thromb Vasc Biol 35:155-62

Showing the most recent 10 out of 16 publications