Oxidative mechanism of homocysteine-induced apoptosis in endothelial progenitor cells / 上海交通大学学报（医学版）

ABSTRACT

Objective To investigate the oxidative mechanism of homocysteine ( Hey) -induced apoptosis in endothelial progenitor cells( EPCs). Methods Total mononuclear cells were isolated from mouse bone marrow by Ficoll density gradient centrifugation and were cultured in vitro for 7 d. Adherent cells were harvested and identified by fluorescence microscopy. EPCs were cultured with Hey (0, 50, 100 and 500 μmol/L) for 12, 24 and 48 h, or pretreated with NAC (1 mmol/L), DPI( 10 μmol/L) or SB203580 (10 μmol/L) for 30 min, then cultured with 500 μmol/L Hey for 24 h. Apoptosis was detected by Annexin-V/PI flow cytometry, levels of reactive oxygen species (ROS) in cells were measured using H2DCF-DA as a fluorescence probe, NADPH oxidases were evaluated with lucigenin-enhanced chemilumine9cence, and NO in the supernatant was determined by nitrate reductase assay. Results Hey induced EPCs apoptosis, ROS accumulation, NADPH oxidase activation and decrease of NO in a time-dose dependent manner( P <0.05 or P < 0.01). Pretreatment with NAC, DPI and SB203580 could inhibit these effects (P < 0.05 or P < 0.01). Conclusion Hey could activate NADPH oxidase, induce ROS increase and NO decrease, and activate p38MAPK to enhance EPCs apoptosis.