The Effects Of Protectin D1(PD1) On The Adhesion Of Neutrophils To Human Umbilical Vein Endothelial Cells Induced By Lipopolysaccharide (LPS)

Objective:To investigate the effects and mechinism of PD1 on the adhesion of neutrophils (PMNs) to human umbilical vein endothelial cells(HUVECs) induced by lipopolysaccharide (LPS).Methods:Human umbilical vein endothelial cells(HUVECs)cultured in vitro was randomly divided into five groups for the experiment of PMNs-HUVECs adhesion.There were control group ,LPS group ,200nM PD1 pretreated PMNs group (P200), 20nM PD1 pretreated PMNs group (P20), 2nM PD1 pretreated PMNs group (P2).LPS(1ug/ml) was used to stimulate HUVECs for 6h except the control group,and then BCECF-AM labled PMNs was put into the HUVECs monolayers for 30min.Then PMNs adhesion was detected by fluorescence microscope and spectrofluorophotometer. Flow cytometry was applied to assess lymphocyte function-associated antigen (LFA-1) expression in various PD1 treated PMNs.Werstern bloting was used to assess s intercellular adhesion molecuh-1(ICAM-1) expression in various PD1 treated HUVECs.Results: compared to the LPS group,the PMNs-HUVECs adhesion of P2,P20,P200 were significant decreased(P<0.05),and the PD1 inhibited the adhesion of PMNs to HUVECs in a concerntration-dependent manner. The various PD1 were lower LFA-1 expression in PMNs(P<0.05),but have no significant effects on ICAM-1 expression in HUVECs.Conclusion:PD1 can inhibit the adhesion of PMNs to HUVECs in a concerntration-dependent manner, this may be related to the decrease of LFA-1 expression in PMNs.