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* GIGA-Research Human Genetics Unit,
GIGA-Research Laboratory of Connective Tissue Biology,
Cellular Biology Unit, and
GIGA Bioinformatics Platform, University of Liège, Liège, Belgium;
¶ Department of Cardiology, Cardiovascular Research Institute, Maastricht, The Netherlands; and
|| Department of Cell Physiology and Pharmacology, University of Leicester, Leicester, United Kingdom
ATP, released at the leading edge of migrating neutrophils, amplifies chemotactic signals. The aim of our study was to investigate whether neutrophils express ATP-gated P2X1 ion channels and whether these channels could play a role in chemotaxis. Whole-cell patch clamp experiments showed rapidly desensitizing currents in both human and mouse neutrophils stimulated with P2X1 agonists, 
β-methylene ATP (βMeATP) and β
MeATP. These currents were strongly impaired or absent in neutrophils from P2X1–/– mice. In Boyden chamber assays, βMeATP provoked chemokinesis and enhanced formylated peptide- and IL-8-induced chemotaxis of human neutrophils. This agonist similarly increased W-peptide-induced chemotaxis of wild-type mouse neutrophils, whereas it had no effect on P2X1–/– neutrophils. In human as in mouse neutrophils, βMeATP selectively activated the small RhoGTPase RhoA that caused reversible myosin L chain phosphorylation. Moreover, the βMeATP-elicited neutrophil movements were prevented by the two Rho kinase inhibitors, Y27632 and H1152. In a gradient of W-peptide, P2X1–/– neutrophils migrated with reduced speed and displayed impaired trailing edge retraction. Finally, neutrophil recruitment in mouse peritoneum upon Escherichia coli injection was enhanced in wild-type mice treated with βMeATP, whereas it was significantly impaired in the P2X1–/– mice. Thus, activation of P2X1 ion channels by ATP promotes neutrophil chemotaxis, a process involving Rho kinase-dependent actomyosin-mediated contraction at the cell rear. These ion channels may therefore play a significant role in host defense and inflammation.
The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked advertisement in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
1 This work was supported by the Belgian National Fund for Scientific Research (Project no 1.5.203.06), Belgian Science Policy (IAP6/18), and "Fondation Léon Frédéricq" and "Fonds spéciaux pour la recherche" (Project no I-05/02) of the University of Liège and Wellcome Trust C.L. is a postdoctoral researcher at the Belgian National Fund for Scientific Research and received a fellowship from the Simone and Cino del Duca Foundation; K.F. was supported by the Belgian Science Policy (IAP 6/18); and C.F. was supported by a "Fond pour la recherche industrielle et agricole" fellowship. C.O. is a research associate at the Belgian National Fund for Scientific Research.
2 C.L. and K.F. contributed equally to this work.
3 Address correspondence and reprint requests to Dr. Cécile Oury, University of Liège GIGA-Research Human Genetics Unit, Tour GIGA B34, Avenue de l’Hôpital 1, B-4000 Liège, Belgium. E-mail address: cecile.oury{at}ulg.ac.be
4 Abbreviations used in this paper: PI3P, 3'-phosphoinositol lipid; CaM, calmodulin; CI, chemotactic index; GEF, guanine nucleotide exchange factor; MeATP, methylene ATP; MLC, myosin L chain; WT, wild type.
5 The online version of this article contains supplemental material.
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