Effects of stromal cell-derived factor-1α on senescence of endothelial stem cells from peripheral blood / 中国药理学与毒理学杂志

ABSTRACT

OBJECTIVE To investigate whether stromal cell-derived factor-1α (SDF-1α) might be able to prevent senescence of endothelial stem cell (ESC) and also study its effects on the telomerase activity. METHODS Total mononuclear cells (MNCs) were isolated from peripheral blood by density gradient centrifugation, and then the cells were plated on fibronectin-coated culture dishes. After cultured for 4 d, attached cells were divided into control and SDF-1α 1, 10, 50 and 100 μg·L~(-1) groups. ESC became senescent as determined by acidic β-galactosidase staining. The proliferation of ESC was assessed by MTT assay and colony-forming capacity. Telomerase activity was measured by telomerase-PCR ELISA and the phosphorylation of Akt was determined by using Western blotting. RESULTS Ex vivo prolonged cultivation of ESC led to rapid onset of ESC senescence. Compared with control group, SDF-1α concentration-dependently inhibited the onset of ESC senescence, maximum at 100 μg·L~(-1) (40.8±7.1 vs 17.5±3.0; P<0.01). Moreover, SDF-1α 100 μg·L~(-1) increased ESC proliferation (0.22±0.02 vs 0.39±0.04; P<0.01) and ESC colony-forming activity (7.8±2.2 vs 22.4±3.4). Compared with control group, SDF-1α 100 μg·L~(-1) also increased telomerase activity (0.34±0.05 vs 0.57±0.09; P<0.01). In addition, SDF-1α treatment of ESC stimulated a concentration- and time-dependent Akt phosphorylation. CONCLUSION SDF-1α-induced prevention of ESC senescence leads to the potentiation of proliferative activity, and clonal expansion, which may be related to the activation of telomerase and Akt phosphorylation.