The relationship between number and function of EPCs and concentration of VEGF165 and SDF-1 in coronary artery spasm

We aimed at investigating the functions of endothelial progenitor cells (EPCs) in the pathophysiology of coronary artery spasm (CAS) and coronary artery disease (CAD), as well as to evaluate the correlation of these diseases with the number and function of EPCs, the plasma concentration of vascular endothelial growth factor 165 (VEGF165) and stromal cell-derived factor 1 (SDF-1).

Participants were recruited into three groups, CAS, CAD and the control. The number and functions of early EPCs and outgrowth endothelial cells (OECs) were determined in peripheral blood samples, and the endothelial function was evaluated by measuring endothelium-dependent flow-mediated vasodilation (FMD).

No differences of baseline characteristics were found among CAS, CAD, and the control groups. The OECs isolated from CAS and CAD exhibited significant decrease in the percentage of CD34+/CD45- population, OEC colony formation, OEC proliferation and OEC tubulogenesis, nitric oxide (NO) production, endothelial nitric oxide synthase (eNOS) activity, and the phosphorylation level at Ser1177 of eNOS, compared with OECs isolated from control participants. Meanwhile, FMD was significantly reduced in CAS and CAD (CAS, 4.1% ± 1.9%; CAD, 4.3% ± 1.8%; control, 11.2% ± 3.5%). FMD was positively correlated to OEC functions including NO production, eNOS phosphorylation, colony formation, and proliferation. No differences of plasma VEGF165 and SDF-1 concentrations were recorded among these three groups. Similarly, there was no correlation between plasma VEGF165 (and SDF-1) concentration and EPC number and function.

EPCs show the potential of repairing damaged endothelium in CAS and CAD.