Effects of aspirin on number,activity and inducible nitric oxide synthase of endothelial progenitor cells from peripheral blood

Aim:To investigate whether aspirin has an influence on endothelial progenitorcells(EPC).Methods:Total mononuclear cells(MNC)were isolated from periph-eral blood by Ficoll density gradient centrifugation,then cells were plated onfibronectin-coated culture dishes.After 7 d of culture,attached cells were stimu-lated with aspirin(to achieve final concentrations of 1,2,5,and 10 retool/L)for 3,6,12,and 24 h.EPC were characterized as adherent cells that were double positivefor 1,1-dioctadecyl-3,3,3,3-tetramethylindocarbocyanine low density lipoprotein(DiLDL)uptake and lectin binding by direct fluorescent staining.EPC prolifera-tion and migration were assayed using a 3-(4,5-dimethyl-2 thiazoyl)-2,5-diphenyl-2H-tetrazolium bromide(MTT)assay and a modified Boyden chamber assay,respectively.An EPC adhesion assay was performed by replating the EPC onfibronectin-coated dishes,and then adherent cells were counted.In vitrovasculogenesis activity was assayed by using an in vitro vasculogenesis kit.Inducible nitric oxide synthase(iNOS)was assayed by Western blotting.Results:Incubation of isolated human MNC with aspirin decreased the number of EPC.Aspirin also decreased the proliferative,migratory,adhesive,and in vitrovasculogenesis capacity of EPC,and also their iNOS levels in a concentration-and time-dependent manner.Conclusion:Aspirin decreases(1)the number ofEPC;(2)the proliferative,migratory,adhesive and in vitro vasculogenesis capaci-ties of EPC;and(3)iNOS levels in EPC.