Aging diminished circulating endothelial progenitors cells in ApoE-deficient mice.

LEMBO, C; RENNA NF; CRUZADO M; MIATELLO RM; CASTRO C

Mendoza

Jornada; XXVI Reunión Anual de la Sociedad de Biología de Cuyo; 2008

Sociedad de Biologia de Cuyo

Level of circulating endothelial progenitor cells (EPCs), characterized by expressing the antigens CD34 and vascular endothelial growth factor receptor-2 (VEGFR-2), is considered a better predictor of vascular reactivity than the presence of conventional risk factors. This study was performed to isolate and characterize circulating EPCs from atherosclerosis-prone ApoE-/- mice  and C57BL6 mice, during aging. Heparin blood samples from severely atherosclerotic, 10-month-old ApoE-/- mice and non atherosclerotic, 4-week-old ApoE-/- mice were collected. Cells were stained with FITC-conjugated CD34 and phycoerythrin-conjugated VEGFR-2 antibodies (BD). Flow cytometry analysis was performed using FACS (BD). Confocal immunofluorescence was also assessed. Circulating CD34+/VEGFR2+ cells differed numerically between young and old ApoE-/- mice (0.18% ± 0.02 vs. 0.021% ± 0.007; n=4 each group, p<0.005) and between young and old C57BL6 mice (0.21%± 0.02 vs 0.063%±0,006; n=4 each group, p<0.005).Despite persistent hypercholesterolemia in both groups, quantification of plaque area, with Oil red O-stained, in the aorta and femoral artery showed no atheroma in young mice and many atheromatous plaques in old mice. Our data suggest that aging results in a lower number of circulating endothelial progenitor cells that could be associated to enhanced atherosclerosis.