CD39 is the prototype ATP/ nucleoside triphosphate diphosphohydrolase (ATPDase/NTPDase; EC 3.6.1.5) member of a family of E-type ectonucleotidases. CD39 modulates purinergic receptor-mediated signaling, following the hydrolysis of ATP and ADP, but also facilitates generation of adenosine for intracellular transport from extracellular adenine nucleotides. Although CD39 appears to be regulated and widely expressed within the vasculature, the functional significance of ectoenzyme expression by the endothelium is unclear. Ectonucleotidases could be involved in the regulation of vascular inflammatory reactions by influencing platelet microthrombi formation, endothelial cell activation or apoptosis and systemic purine homeostasis. To study the functional significance of the vascular NTPDase, the investigators have developed antisense reagents, recombinant adenoviruses and generated CD39-deficient and null mice by homologous recombination. These mutant mice have been shown to be fully viable but have a bleeding diathesis. Platelet hypofunction, secondary to selective purinergic P2Y1 receptor desensitization, can be demonstrated. In keeping with the predicted loss of this vascular thromboregulatory mechanism, fibrin deposition has been observed within the vasculature at multiple sites; the mutant mice also respond adversely to vascular insults and their cardiac xenotransplants rapidly fail. The role of CD39 in modulating differing endothelial cell purinoreceptor mediated effects in vitro and consequent thrombotic reactions in vivo will be further examined in this proposal. Vascular responsiveness to systemic platelet activation, ischemia-reperfusion injury and xenograft rejection will be evaluated in selected vascularized murine tissues over-expressing NTPDase biochemical activtity and in mutant mice deficient in CD39. Reconstitution experiments, using soluble NTPDases, will be performed in parallel. Purinergic mechanisms by which CD39 influences platelet and cellular activation appear to differ from those associated with endothelial constitutive nitric oxide synthase (eNOS), a second aspirin-insensitive thromboregulatory system. These pathways may be additive or synergistic and will be studied by in vitro systems and by modulating NO-activity in CD39 mice. The generation of mice deficient in both eNOS and CD39 will also be undertaken. These double knock-outs may be viable; however, a lethal phenotype will be also informative. These experiments should indicate the involvement of the vascular NTPDase/CD39, and also elucidate interactions with NOS systems, in certain vascular inflammatory disorders observed in human disease states.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL063972-03
Application #
6527273
Study Section
Surgery, Anesthesiology and Trauma Study Section (SAT)
Program Officer
Massicot-Fisher, Judith
Project Start
2000-09-01
Project End
2004-07-31
Budget Start
2002-08-01
Budget End
2003-07-31
Support Year
3
Fiscal Year
2002
Total Cost
$261,000
Indirect Cost
Name
Beth Israel Deaconess Medical Center
Department
Type
DUNS #
076593722
City
Boston
State
MA
Country
United States
Zip Code
02215
Wang, Yan; Begum-Haque, Sakhina; Telesford, Kiel M et al. (2014) A commensal bacterial product elicits and modulates migratory capacity of CD39(+) CD4 T regulatory subsets in the suppression of neuroinflammation. Gut Microbes 5:552-61
Roberts, Veena S; Cowan, Peter J; Alexander, Stephen I et al. (2014) The role of adenosine receptors A2A and A2B signaling in renal fibrosis. Kidney Int 86:685-92
O'Keeffe, Mary G; Thorne, Peter R; Housley, Gary D et al. (2012) Hair cell specific NTPDase6 immunolocalisation in vestibular end organs: potential role of purinergic signaling in vestibular sensory transduction. J Vestib Res 22:213-9
Künzli, Beat M; Berberat, Pascal O; Dwyer, Karen et al. (2011) Variable impact of CD39 in experimental murine colitis. Dig Dis Sci 56:1393-403
Deaglio, Silvia; Robson, Simon C (2011) Ectonucleotidases as regulators of purinergic signaling in thrombosis, inflammation, and immunity. Adv Pharmacol 61:301-32
Eltzschig, Holger K; Robson, Simon C (2011) NT5E mutations and arterial calcifications. N Engl J Med 364:1577-8; author reply 1579-80
Cowan, Peter J; Robson, Simon C; d'Apice, Anthony J F (2011) Controlling coagulation dysregulation in xenotransplantation. Curr Opin Organ Transplant 16:214-21
Schoffstall, Brenda; LaBarbera, Vincent A; Brunet, Nicolas M et al. (2011) Interaction between troponin and myosin enhances contractile activity of myosin in cardiac muscle. DNA Cell Biol 30:653-9
Feng, Lili; Sun, Xiaofeng; Csizmadia, Eva et al. (2011) Vascular CD39/ENTPD1 directly promotes tumor cell growth by scavenging extracellular adenosine triphosphate. Neoplasia 13:206-16
Shalev, Itay; Schmelzle, Moritz; Robson, Simon C et al. (2011) Making sense of regulatory T cell suppressive function. Semin Immunol 23:282-92

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