Effects of Rapamycin and Paclitaxel on the Number and Activity of Bone Marrow-Derived Endothelial Progenitor Cells

Objective:To investigate the effects of rapamycin and paclitaxel on the number and activity of bone marrow-derived endothelial progenitor cells(EPCs).Methods:Bone marrow mononuclear cells were isolated from rat bone marrow by centrifugation and they were cultured on gelatin-coated dishes.After 7-day culture,adherent cells were treated with rapamycin or paclitaxel in a series of concentrations(0.1μg/mL,1μg/mL,and 5μg/mL) for 24 h.EPCs were identified as adherent cells double positive for DiI-acLDL-uptake and lectin binding by direct fluorescent staining.Proliferation and migration of EPCs were determined using MTT assay and modified version of the Boyden chamber assay,respectively.EPCs adhesion assay was performed by replanting the cells on gelatin-coated dishes,and then adherent cells were counted.Results: Incubation of EPCs with rapamycin or paclitaxel decreased the number of EPCs.Rapamycin and paclitaxel also decreased the proliferative,migratory,and adhensive capacity of EPCs in a concentration-dependent manner(P0.05).At the same time,the influence of the same concentrations of rapamycin and paclitaxel on the number and function of EPCs showed no significant differences.Conclusions: Rapamycin and paclitaxel decreased the number,as well as the proliferative,migratory,and adhensive capacity of EPCs.