Changes in endothelial progenitor cell function in elderly patients with permanent atrial fibrillation and their clinical significance / 中华老年医学杂志

ABSTRACT

Objective To investigate changes in the number and function of endothelial progenitor cells (EPCs) in elderly patients with permanent atrial fibrillation(AF).Methods This prospective study included 35 elderly patients in each the permanent atrial fibrillation group and the control group.The numbers of circulating CD34+/KDR+ cells in the two groups were determined by flow cytometry.After two sets of peripheral blood samples were taken,mononuclear cells were isolated through density gradient centrifugation and cultured in vitro.EPC colonies were identified by the methylthiazolyldipheny-tetrazolium(MTT) assay and adhesion assay.The proliferation,adhesion and vasculogenesis of EPC colonies were determined by Matrigel culture.Enzyme-linked immunosorbent assay and nitric acid reductase assay were used to measure the secretion of vascular endothelial growth factor (VEGF) and nitric oxide (NO) in EPCs.Results The numbers of CD34+/KDR+ cells were lower in the AF group than in the control group (20.0±12.7)/104 vs.(77.9±58.9)/104 (P＜0.05).The number of EPC colonies in the atrial fibrillation group was significantly lower than that in the control group (1.8 ± 0.6) CFU vs.(3.5 ± 0.8) CFU (P ＜ 0.01).The proliferation,adhesion and vasculogenesis of EPC colonies in the AF group decreased,compared with the control group (each P＜0.01 or 0.05).Paracrine secretion of VEGF in the AF group (27.4±9.9)ng/L was lower than that in the control group (41.9±7.3)ng/L (P＜0.01) and paracrine production of NO in the AF group also decreased (P＜0.05).Conclusions EPCs In elderly patients with permanent atrial fibrillation show decreased numbers and reduced proliferation,adhesion and vasculogenesis.Paracrine VEGF and NO secretion is down as well.