Spontaneous cell fusion in macrophage cultures expressing high levels of the P2Z/P2X7 receptor.
Mouse and human macrophages express a plasma membrane receptor for extracellular ATP named P2Z/P2X7. This molecule, recently cloned, is endowed with the intriguing property of forming an aqueous pore that allows transmembrane fluxes of hydrophylic molecules of molecular weight below 900. The physiological function of this receptor is unknown. In a previous study we reported experiments suggesting that the P2Z/P2X7 receptor is involved in the formation of macrophage-derived multinucleated giant cells (MGCs; Falzoni, S., M. Munerati, D. Ferrari, S. Spisani, S. Moretti, and F. Di Virgilio. 1995. J. Clin. Invest. 95:1207- 1216). We have selected several clones of mouse J774 macrophages that are characterized by either high or low expression of the P2Z/P2X7 receptor and named these clones P2Zhyper or P2Zhypo, respectively. P2Zhyper, but not P2Zhypo, cells grown to confluence in culture spontaneously fuse to form MGCs. As previously shown for human macrophages, fusion is inhibited by the P2Z/P2X7 blocker oxidized ATP. MGCs die shortly after fusion through a dramatic process of cytoplasmic sepimentation followed by fragmentation. These observations support our previous hypothesis that the P2Z/P2X7 receptor is involved in macrophage fusion.
Chiozzi
P
P
Institute of General Pathology, University of Ferrara, I-44100 Ferrara, Italy.
Sanz
J M
JM
Ferrari
D
D
Falzoni
S
S
Aleotti
A
A
Buell
G N
GN
Collo
G
G
Di Virgilio
F
F
D000255:Adenosine Triphosphate / Q000031:analogs & derivatives / Q000494:pharmacology; D000818:Animals; D002449:Cell Aggregation; D002459:Cell Fusion / Q000187:drug effects; D002460:Cell Line; D015726:Giant Cells / Q000166:cytology; D006593:Hexokinase / Q000494:pharmacology; D006801:Humans; D008264:Macrophages / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D051379:Mice; D010641:Phenotype; D058919:Purinergic P2 Receptor Antagonists; D018048:Receptors, Purinergic P2 / Q000378:metabolism*; D058486:Receptors, Purinergic P2X7
C546468:P2RX7 protein, human; C546469:P2rx7 protein, mouse; D058919:Purinergic P2 Receptor Antagonists; D018048:Receptors, Purinergic P2; D058486:Receptors, Purinergic P2X7; C017199:2',3'-dialdehyde ATP; D000255:Adenosine Triphosphate; D006593:Hexokinase