Upregulated Expression Of Substance P(SP)and NK1R In Eczema And SP Induced Mast Cell Accumulation

ObjectiveTo investigate the expression of substance P(SP)in inflammatory cells in eczema,and its ability in induction of mast cell accumulation.MethodsELISA,flowcytometry,immunohistochemistry,trans-epithelial cell migration assay,and mouse peritoneal model were employed to explore the expression of SP and NK1 R on peripheral blood leukocytes and mast cells from patients with eczema,and the influence of SP on mast cell accumulation.ResultsPlasma SP and IL-17 A levels in eczema patients were higher than that in HC subject.The percentages of SP+ and NK1R+ expression populations of monocytes,helper T cells,natural killer T cells,and basophils in peripheral blood of eczema patients were markedly elevated.It was observed that not only absolute number of mast cells,but also SP+ and NK1R+ mast cells are enhanced in the lesion skin of eczema.SP showed a potent chemoattractant action on mast cells as assessed by a mouse peritoneal model and a trans-endothelium cell migration assay.SP induced mast cell accumulation appears a CD18/CD11 a complex,L-selectin and ICAM-1 dependent event which can be blocked by a NK-1R antagonist RP67580.ConclusionsElevated expression of SP in patients with eczema,and the ability of SP in induction of mast cell accumulation indicate strongly that SP is a potentproinflammatory mediator,which contributes to the pathogenesis of eczema.Inhibitors of SP and blockers of NK1 R are likely useful agents for treatment of eczema.