Neuropeptide S stimulates human monocyte chemotaxis via NPS receptor activation

Neuropeptide S (NPS) produces several biological actions by activating a formerly orphan GPCR, now named NPS receptor (NPSR). It has been previously demonstrated that NPS stimulates murine leukocyte chemotaxis in vitro. In the present study we investigated the ability of NPS, in comparison with the proinflammatory peptide formyl-Met-Leu-Phe (fMLP), to stimulate human monocyte chemotaxis. At a concentration of 10−8 M fMLP significantly stimulated chemotaxis. NPS produced a concentration dependent chemotactic action over the concentration range 10−12 to 10−5 M. The NPSR antagonists [d-Cys(tBu)5]NPS, [tBu-d-Gly5]NPS and SHA 68 were used to pharmacologically characterize NPS action. Monocyte chemoattractant effect of NPS, but not fMLP, was completely blocked by either peptide antagonists or SHA with the nonpeptide molecule being more potent. None of the NPSR antagonists modified per se random cell migration. Thus, the present study demonstrated that NPS is able to stimulate human monocyte chemotaxis and that this effect is entirely due to selective NPSR activation.