Endothelial P2Y2 receptor regulates LPS-induced neutrophil transendothelial migration in vitro

Previous studies showed that P2 receptors are involved in neutrophil migration Via Stimulation Of chemokine release and by facilitating chemoattractant gradient sensing Here. we have investigated whether these receptors are involved in LPS-induced neutrophil transendothelial migration (TEM) using a Boyden chamber where neutrophils migrated through a layer of lipopolysaccharide (LPS)-stimulated human umbilical vein endothelial cells (HUVECs) In line with a role of P2 receptors, neutrophil TEM was inhibited by the P2 receptor antagonists suramin and reactive blue 2 (RB-2) acting on the basolateral, but not luminal, HUVECs' P2 receptors HUVECs express P2Y(1), P2Y(2), P2Y(4), P2Y(6) and P2Y(11). The involvement of P2Y(4) was unlikely as this receptor is insensitive to suramin while P2Y(1), P2Y(6) and P2Y(11) were excluded with available selective antagonists. leaving P2Y(2) is the only candidate Indeed, the P2Y(2) knockdown in HUVECs inhibited neutrophil TEM compared to control HUVECs transfected with scrambled siRNA Moreover, UTP, a P2Y(2) ligand. markedly potentiated LPS-induced TEM Interestingly. IL-8 and ICAM-1 had a modest effect on neutrophil TEM in this 3 h assay which was significantly diminished by the inhibition of Rho kinase in HUVECs with Y27632 In summary. endothelial P2Y(2) receptors control the early LPS-induced neutrophil TEM in vitro via Rho kinase activation (C) 2009 Elsevier Ltd All rights reserved