Effects Of Low-molecular-weight Heparin On Number And Activity Of Endothelial Progenitor Cells From Peripheral Blood

AIMTo investigate whether endothelial progenitor cells (EPCs )are involved in the mechanism of low-molecular-weight heparin (LMWH )in treating cardiovascular disease. METHODSTotal mononuclearcells(MNCs)were isolated from peripheral blood by Ficoll density gradient centrifugation .Cells were plated on fibronectin -coated culture dishes .After 7Dculture ,attacted cells were stimulated with LMWH(to make a series of final concentrations:50,100, 200and400 KU/L~-1)or vehicle control for the respective time points(6,12,24,48and72H).EPCs were characterized as adherent cells double positive for Dil-acLDL-uptake and lectin binding by direct fluorescent staining under a laser scanning confocal microscope .EPCsproliferation and migration v/ere assayed with MTTassey and modified Boyden chamber assay,respectively.EPCs adhesion assay was performed by replating it on fibronectin-coated dishes ,and then adherent cells were counted. RESULTSIncubation of isolated human MNCs with LMWH dose-andtime-dependently increased the number of EPCs,maximum at 200 KU/L~-1 45h(control vs200 KU/L~-1 44 ± 5 vs 112 ± 9). In addition , LMWH alsopromoted EPC proliferation(control vs 200 KU/L~-1 LMWH, 0.504 ± 0.097 vs 0.828 ± 0.109),migration(control vs 200 KU/L~-1LMWH, 8 ± 6 vs 40 ± 8)and adhesion(control vs 200 KU/L~-1 LMWH,9±4 vs 29±4) in a concentration-dependent manner. CONCLUSIONBy increasing the number of EPCs,and enhancing its proliferation, migration and adhesion may be the action mechanism of LMWH in the treatment of cardiovascular disease.