Abstract:OBJECTIVE: To study the effect of H2O2 on the proliferation and apoptosis of endothelial progenitor cells (EPCs) and the antogonistic effects of catechin on the cell apoptosis induced by H2O2 in rats. METHODS: Immuno-fluoreascence assay was applied to detect CD34, CD133 and VEGFR-2 expression. EPCs of generation 2 were divided into control cells, H2O2-treated cells and catechin-H2O2-treated cells (H2O2: 100 mg/L; catechin: 10 mg/L). Genomic DNA was extracted by the conventional method after intervention for the analysis of apoptosis ladder pattern. The MTT assay was applied to detect proliferation rate of EPCs. RESULTS: The cultured cells at day 10 expressed CD34, CD133 and VEGFR-2. DNA apoptosis ladder pattern appeared in H2O2 -treated cells 2 days after intervention. After 3 days of intervention DNA apoptosis ladder pattern appeared in both H2O2-treated cells and H2O2-catechin-treated cells, with more ladders and grayer scale in H2O2 -treated cells. Compared with the controls, H2O2-treated cells and H2O2-catechin-treated cells showed significantly decreased proliferation rate (P<0.01), with the lowest proliferation rate at the 2nd day (P<0.05). The H2O2-catechin-treated cells showed increased proliferation rate than H2O2-treated cells at the 1st, 2nd and 3rd days. CONCLUSIONS: H2O2 may impair EPCs proliferation and induce EPCs apoptosis. Catechin may increase the capacity of EPCs for the resistance to apoptosis induced by H2O2.［Chin J Contemp Pediatr, 2009, 11 (1):61-64］
