[Effects of hypercholesterolemia on the number and activity of endothelial progenitor cells in peripheral blood].

Objective: To investigate whether hypercholesterolemia has influences on the number and activity of endothelial progenitor cells (EPCs).

Methods: Mononuclear cells were isolated from patients with hypercholesterolemia (n = 20) and age-matched control subjects (n = 20). EPCs were characterized as adherent cells double positive for DiLDL-uptake and lectin binding by direct fluorescent staining under a laser scanning confocal microscope. EPCs proliferation and migration were assayed by MTT assay and modified Boyden chamber assay, respectively. EPCs adhesion assay was performed by replating cells on fibronectin-coated dishes, then counting the adherent cells.

Results: The number of EPCs was significantly reduced in patients with hypercholesterolemia as compared with that in control subjects [(41.8 +/- 8.7 vs 64.5 +/- 16.6) EPCs/x 200 fields; P < 0.05] and it was inversely correlated with total cholesterol levels (r = -0.659, P < 0.001) and LDL cholesterol levels (r = -0.611, P < 0.001). In addition, EPCs proliferative, migratory and adhesive capacity were also impaired.

Conclusion: It is suggested that a novel pathophysiological mechanism of hypercholesterolemia may be defined i.e. reduction of EPCs with decreased functional activity.