Activities of circulating endothelial progenitor cells in patients with in-stent restenosis

Abstract

To observe the number and activities of circulating endothelial progenitor cells (EPCs) in patients with in-stent restenosis. Peripheral blood samples were collected from 15 patients with angiographically restenosis, and 17 baseline characteristics-matched patients without angiographically restenosis (control group). Mononuclear cells were isolated by Ficoll density-gradient centrifugation and plated on dishes coated with human fibronectin. After 7 days in culture, the nature of EPCs was characterized with anti-CD34 and anti-KDR, specific surface antibodies of EPC, and confirmed further with the use of fluorescein isothiocyanate-labeled ulex europaeus agglutinin-I (FITC-UEA-I) and DiI (1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine percolate)-labeled acetylated low-density lipoprotein (DiI-acLDL) by laser scanning confocal microscopy. The number of EPCs was counted in a blinded manner. EPCs were inoculated onto the culture plate and 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl-2H-tetrazolium bromide assay was used to measure the A value by enzyme labeling instrument to evaluate the proliferation. The migration of EPCs was assayed by scratch assay. EPC adhesion was performed by replating cells on fibronectin-coated dishes and then counting the adherent cells. Results The number of EPCs of the patients with in-stent restenosis was 4.97 +/- 1.42/well, significantly lower than that of the control group (17.2 +/- 3.90/well, P = 0.001). MTT assay showed that the proliferative activities of the in-stent restenosis group was 1.37 +/- 0.32 times the baseline value, significantly lower than that of the control group (2.01 +/- 0.62, P < 0.05). The number of migrating EPCs of the in-stent restenosis group was remarkably lower than that of the control group. There was no significant difference in the adherent activity between the two groups. Conclusion The number, proliferation activity, and migration activity of the EPCs patients with in-stent restenosis are all significantly lower, which may contribute to the mechanism of in-stent restenosis.