P2Y11 Purinoceptor Mediates the ATP-Enhanced Chemotactic Response of Rat Neutrophils

Abstract

ATP and hydrolysis products of ATP like adenosine regulate the chemotaxis of neutrophils by activating purinoceptors and adenosine receptors. The present study was designed to examine exogenous ATP, activation of purinoceptors, and activation of A3 adenosine receptor as key steps in the signal cascades that control cell orientation and migration of rat neutrophils. One or more of those steps might be potential therapeutic targets for treatment of inflammatory diseases. The chemotaxis of rat neutrophils was stimulated with N-formyl-methionyl-leucyl-phenylalanine (fMLP) and measured with an EZ-TAXIScan apparatus. The effects of apyrase, exogenous ATP, suramin (P2X and P2Y blocker), PPADS (a P2X blocker), TNP-ATP (P2X1 and P2X3 antagonist), and Reactive Blue 2 (a P2Y blocker) on the chemotactic response were also investigated. Rat neutrophil chemotaxis was significantly suppressed by apyrase. fMLP induced rat neutrophil chemotaxis was potentiated by ATP, blocked by suramin, not affected by PPADS or TNP-ATP, and significantly inhibited by RB-2. Western blotting showed that A3, P2Y2, and P2Y11 were expressed in rat neutrophils. The chemotactic response of rat neutrophils to fMLP stimulation is potentiated by ATP via P2Y11 purinoceptors but not P2X purinoceptors or A3 adenosine receptor, and that the response plays a critical role in host defense and pathogenicity.[Supplementary Movies: available only at http://dx.doi.org/10.1254/jphs.12173FP] Keywords:: chemotaxis, extracellular nucleotide, EZ-TAXIScan, neutrophil, purinoceptor