We have investigated responses of human monocyte/macrophage cells to extracellular ATP (ATPe). Freshly isolated peripheral blood monocytes showed responses linked to P2Y but not P2Z purinergic receptors; however, during in vitro macrophage differentiation, these cells also exhibited responses suggestive of the presence of the membrane-permeabilizing P2Z receptor. In fact, in human macrophages a brief (15-min) exposure to ATPe, but not other nucleotides, caused (1) a rapid and long-lasting plasma membrane depolarization; (2) a large increase in intracellular Ca2+ concentration followed by efflux of the Ca2+ indicator; (3) uptake of low molecular weight hydrophilic molecules such as Lucifer yellow and ethidium bromide; and (4) cell rounding, swelling, and eventual release of the cytoplasmic enzyme lactate dehydrogenase. rIFN-gamma enhanced both membrane-permeabilizing and cytotoxic ATPe effects. Membrane permeabilization and cytotoxicity were fully blocked by pretreatment of the cells with oxidized ATP, a compound recently shown to block P2Z receptors covalently in macrophages. Blocking of the P2Z receptor by oxidized ATP also inhibited multinucleated giant cell generation stimulated by concanavalin A or rIFN-gamma without decreasing monocyte migration or membrane adhesion molecule expression. These data suggest that human macrophages express rIFN-gamma-modulated purinergic P2Z receptors in vitro and hint at a role for these plasma membrane molecules in the generation of macrophage polykarions.

The Purinergic P2Z Receptor of Human Macrophage Cells: Characterization and Possible Physiological Role

FALZONI, Simonetta;FERRARI, Davide;SPISANI, Susanna;DI VIRGILIO, Francesco
1995

Abstract

We have investigated responses of human monocyte/macrophage cells to extracellular ATP (ATPe). Freshly isolated peripheral blood monocytes showed responses linked to P2Y but not P2Z purinergic receptors; however, during in vitro macrophage differentiation, these cells also exhibited responses suggestive of the presence of the membrane-permeabilizing P2Z receptor. In fact, in human macrophages a brief (15-min) exposure to ATPe, but not other nucleotides, caused (1) a rapid and long-lasting plasma membrane depolarization; (2) a large increase in intracellular Ca2+ concentration followed by efflux of the Ca2+ indicator; (3) uptake of low molecular weight hydrophilic molecules such as Lucifer yellow and ethidium bromide; and (4) cell rounding, swelling, and eventual release of the cytoplasmic enzyme lactate dehydrogenase. rIFN-gamma enhanced both membrane-permeabilizing and cytotoxic ATPe effects. Membrane permeabilization and cytotoxicity were fully blocked by pretreatment of the cells with oxidized ATP, a compound recently shown to block P2Z receptors covalently in macrophages. Blocking of the P2Z receptor by oxidized ATP also inhibited multinucleated giant cell generation stimulated by concanavalin A or rIFN-gamma without decreasing monocyte migration or membrane adhesion molecule expression. These data suggest that human macrophages express rIFN-gamma-modulated purinergic P2Z receptors in vitro and hint at a role for these plasma membrane molecules in the generation of macrophage polykarions.
1995
Falzoni, Simonetta; Munerati, M.; Ferrari, Davide; Spisani, Susanna; Moretti, S.; DI VIRGILIO, Francesco
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11392/1202397
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