Under conditions of environmental or ischemic stress, the lungs exhibit a high degree of immunoreactivity and develop a procoagulant phenotype, leading to leukocyte recruitment and microvascular thrombosis. We hypothesized that endothelial cell (EC) expression of a transmembrane protein, CD39 (ectoapyrase), which metabolizes ATP and ADP in the releasate of activated cells, provides a critical mechanism by which ECs inhibit intravascular thrombosis (by inhibiting ADP-mediated platelet/platelet recruitment) and modulate leukocyte traffic(by reducing adhesion receptor expression). Mice null for the CD39 gene, created by deleting exons 4-6 containing the apyrase-conserved domains, exhibit a latent prothrombotic and leukoadhesive phenotype in the setting of unilateral lung ischemia/reperfusion, demonstrating impaired gas exchange and survival. Recombinant soluble CD39, lacking the transmembrane region but retaining apyrase activity, potently suppresses platelet aggregation and leukocyte adhesion to EC monolayers in vitro. Pilot data show that soluble CD39 """"""""reconstituted"""""""" the CD39 null mice to normalize their phenotype and confer functional rescue. Hypoxic CD39 -/-pulmonary ECs also showed increased adhesivity for monocytes and neutrophils, which was reversed by soluble CD39.
The Aims of this project are: (1) To establish the thromboregulatory role of CD39 in the lungs following ischemic, hypoxic, or inflammatory stress, focusing on identification of specific thrombotic or fibrinolytic paradigms which may be modulated by CD39; (2) To determine the leukoregulatory role of CD39 in the lungs following ischemic, hypoxic, or inflammatory stress, and in CD39 +/+ and CD39 -/- pulmonary microvascular ECs exposed to hypoxia or inflammatory mediators. Interactions between leukoadhesive and thrombotic mechanisms will also be studied; and (3) To identify the mechanisms(s) underlying EC CD39-mediated suppression of pulmonary leukosequestration following inflammatory, hypoxic, or ischemic stress, focusing on EC adhesion receptors or their cognate ligands on leukocytes. Overall, experiments will determine how endogenous CD39 modulates thrombosis and recruitment of specific leukocyte cell populations and identify the functional consequences of soluble CD39 administration in in vivo models of pulmonary ischemic, hypoxic, or inflammatory stress. The proposed studies should identify a new CD39-based mechanism of pulmonary vascular thromboregulation and leukoregulation which may lead to a novel therapeutic approach to treat pulmonary ischemia, sepsis, acute respiratory distress syndrome, or other inflammatory/thrombotic diatheses.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
7R01HL069448-03
Application #
6616659
Study Section
Special Emphasis Panel (ZHL1-CSR-P (S1))
Program Officer
Colombini-Hatch, Sandra
Project Start
2001-09-30
Project End
2005-07-31
Budget Start
2003-09-08
Budget End
2004-07-31
Support Year
3
Fiscal Year
2003
Total Cost
$382,500
Indirect Cost
Name
University of Michigan Ann Arbor
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
073133571
City
Ann Arbor
State
MI
Country
United States
Zip Code
48109
Johnson, Jeffrey S; Hamidi, Massihullah; Postle, Bradley R (2010) Using EEG to explore how rTMS produces its effects on behavior. Brain Topogr 22:281-93
Hyman, Matthew C; Petrovic-Djergovic, Danica; Visovatti, Scott H et al. (2009) Self-regulation of inflammatory cell trafficking in mice by the leukocyte surface apyrase CD39. J Clin Invest 119:1136-49
Harada, Hiroaki; Lama, Vibha N; Badri, Linda N et al. (2007) Early growth response gene-1 promotes airway allograft rejection. Am J Physiol Lung Cell Mol Physiol 293:L124-30
Mishra, Snigdha; Fujita, Tomoyuki; Lama, Vibha N et al. (2006) Carbon monoxide rescues ischemic lungs by interrupting MAPK-driven expression of early growth response 1 gene and its downstream target genes. Proc Natl Acad Sci U S A 103:5191-6
Lama, Vibha N; Harada, Hiroaki; Badri, Linda N et al. (2006) Obligatory role for interleukin-13 in obstructive lesion development in airway allografts. Am J Pathol 169:47-60
Marcus, Aaron J; Broekman, M Johan; Drosopoulos, Joan H F et al. (2005) Role of CD39 (NTPDase-1) in thromboregulation, cerebroprotection, and cardioprotection. Semin Thromb Hemost 31:234-46
Marcus, A J; Broekman, M J; Drosopoulos, J H F et al. (2003) Heterologous cell-cell interactions: thromboregulation, cerebroprotection and cardioprotection by CD39 (NTPDase-1). J Thromb Haemost 1:2497-509
Marcus, Aaron J; Broekman, M Johan; Drosopoulos, Joan H F et al. (2003) Metabolic control of excessive extracellular nucleotide accumulation by CD39/ecto-nucleotidase-1: implications for ischemic vascular diseases. J Pharmacol Exp Ther 305:9-16
Ten, Vadim S; Pinsky, David J (2002) Endothelial response to hypoxia: physiologic adaptation and pathologic dysfunction. Curr Opin Crit Care 8:242-50
Pinsky, David J; Broekman, M Johan; Peschon, Jacques J et al. (2002) Elucidation of the thromboregulatory role of CD39/ectoapyrase in the ischemic brain. J Clin Invest 109:1031-40

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