title: NTPDase1 governs P2X7-dependent functions in murine macrophages.
abstract: P2X7 receptor is an adenosine triphosphate (ATP)-gated ion channel within the multiprotein inflammasome complex. Until now, little is known about regulation of P2X7 effector functions in macrophages. In this study, we show that nucleoside triphosphate diphosphohydrolase 1 (NTPDase1)/CD39 is the dominant ectonucleotidase expressed by murine peritoneal macrophages and that it regulates P2X7-dependent responses in these cells. Macrophages isolated from NTPDase1-null mice (Entpd1(-/-)) were devoid of all ADPase and most ATPase activities when compared with WT macrophages (Entpd1(+/+)). Entpd1(-/-) macrophages exposed to millimolar concentrations of ATP were more susceptible to cell death, released more IL-1beta and IL-18 after TLR2 or TLR4 priming, and incorporated the fluorescent dye Yo-Pro-1 more efficiently (suggestive of increased pore formation) than Entpd1(+/+) cells. Consistent with these observations, NTPDase1 regulated P2X7-associated IL-1beta release after synthesis, and this process occurred independently of, and prior to, cytokine maturation by caspase-1. NTPDase1 also inhibited IL-1beta release in vivo in the air pouch inflammatory model. Exudates of LPS-injected Entpd1(-/-) mice had significantly higher IL-1beta levels when compared with Entpd1(+/+) mice. Altogether, our studies suggest that NTPDase1/CD39 plays a key role in the control of P2X7-dependent macrophage responses.
authors.affiliation: Centre de Recherche en Rhumatologie et Immunologie, Centre Hospitalier Universitaire de Québec, Université Laval, Québec, QC, Canada.
authors.forename: Sébastien A
authors.initials: SA
authors.lastname: Lévesque
authors.forename: Filip
authors.initials: F
authors.lastname: Kukulski
authors.forename: Keiichi
authors.initials: K
authors.lastname: Enjyoji
authors.forename: Simon C
authors.initials: SC
authors.lastname: Robson
authors.forename: Jean
authors.initials: J
authors.lastname: Sévigny
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D015703:Antigens, CD / Q000235:genetics / Q000502:physiology*; D017209:Apoptosis / Q000502:physiology; D001081:Apyrase / Q000172:deficiency / Q000235:genetics / Q000502:physiology*; D001854:Bone Marrow Cells / Q000201:enzymology / Q000378:metabolism; D020169:Caspases / Q000502:physiology; D002463:Cell Membrane Permeability; D003433:Crosses, Genetic; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology; D053583:Interleukin-1beta / Q000378:metabolism; D017737:Macrophages, Peritoneal / Q000201:enzymology* / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D018048:Receptors, Purinergic P2 / Q000502:physiology*; D058486:Receptors, Purinergic P2X7; D051195:Toll-Like Receptor 2 / Q000502:physiology
chemical_list: D015703:Antigens, CD; D015853:Cysteine Proteinase Inhibitors; D053583:Interleukin-1beta; C546469:P2rx7 protein, mouse; D018048:Receptors, Purinergic P2; D058486:Receptors, Purinergic P2X7; C493486:Tlr2 protein, mouse; D051195:Toll-Like Receptor 2; D000255:Adenosine Triphosphate; D020169:Caspases; D001081:Apyrase; C067869:CD39 antigen