ABSTRACT
AIM:To investigate the effect of quercetin on the biological functions of rat bone marrow-derived endothelial progenitor cells (EPCs) and its potential mechanisms.METHODS:The bone marrow-derived mononuclear cells of Sprague-Dawley rats were isolated by density gradient centrifugation.The differentiated EPCs were cultured specially and stained with DiI-Ac-LDL and FITC-UEA-1.CD133+ and FLK-1+ were detected on the cell surfaces.After 14 d, the EPCs were incubated with a PI3K inhibitor BYL719 (3 μmol/L) and an ERK inhibitor FR180204 (15 μmol/L).After incubation of the inhibitors for 2 h, the cells were treated with quercetin at different concentrations (0, 10, 20, 40, 80 and 100 μmol/L).MTT assay and Transwell assay were used to detect cell viability and the number of migratory cells.The protein levels of AKT, eNOS, ERK and their phosphorylated status were determined by Western blot.RESULTS:Quercetin enhanced the viability and migration of the EPCs at a dose-dependent manner.However, the PI3K inhibitor BYL719 suppressed the QUE-induced cell viability and migration.Moreover, ERK inhibitor FR180204 exerted the similar inhibitory effect on the cell viability but had no effect on cell migration.Quercetin activated the phosphorylation of AKT, eNOS and ERK.On the other hand, BYL719 was observed to inhibit the phosphorylation of AKT and ERK.FR180204, however, was showed to inhibit the phosphorylation of ERK only.On the contrast, the stimulatory effects that quercetin exerted on the expression of eNOS and its phosphorylation were suppressed by BYL719 and FR180204.CONCLUSION:Quercetin stimulates the viability and migration of EPCs via PI3K/AKT/eNOS and ERK/eNOS signaling pathway, which would be beneficial for cardiovascular health.