高密度脂蛋白对氧化型低密度脂蛋白诱导内皮细胞凋亡的影响

目的　探讨高密度脂蛋白 (HDL)对氧化型低密度脂蛋白 (ox L DL)诱导体外培养的人血管内皮细胞凋亡的影响及相关机制。方法　 ox L DL 单独或与 HDL 共同处理体外培养的人脐静脉内皮细胞株 (ECV- 30 4 )后 ,通过流式细胞仪、DNA电泳检测细胞凋亡并测定 Caspase- 3酶活性。结果　 10 0 μg/ml和 2 0 0 μg/m l浓度 ox L DL 作用内皮细胞后 ,其细胞凋亡率分别为 2 8.4 0± 5 .30 %、34.72± 4 .6 4 % ,DNA电泳呈典型的梯状图谱 ,Caspase- 3酶活性达到 16 6 .0 1± 16 .4 4、2 6 3.74± 4 6 .6 2 pmd/(m in· mg protein) ,与空白组比较均有显著性差异 (P<0 .0 1)。HDL(2 0 0 μg/ml)与 ox L DL(10 0 μg/ml、2 0 0 μg/m l)共同作用后 ,凋亡率降至 8.0 6± 2 .35 %及 9.4 0± 2 .5 8% ,未出现梯状图谱 ,Caspase- 3酶活性减低 (分别为 6 7.73± 14 .83、111.2 6± 2 7.13min· m g protein) ,与对应的 ox L DL 组比较均差异显著 (P<0 .0 1)。结论　 HDL 能减少 ox L DL 所致体外培养的内皮细胞凋亡 ,这一作用可能与降低Caspase- 3酶活性有关

Impact of High-Density Lipoprotein on the Apoptosis of Endothelial Cells Induced by Oxidized Low-Density Lipoprotein

OBJECTIVE: To investigate the impact of HDL on oxLDL-induced apoptosis of endothelial cells and relevant mechanisms. METHODS: Human umbilical venous endothelial cells (ECV-304) were exposed to oxLDL or oxLDL + HDL. The apoptosis of the endothelial cells was checked by the Flow cytometry and DNA electrophoresis, while caspase-3 activity was meaured simultaneously. RESULTS:The apoptosis rates induced by 100 microg/ml and 200 microg/ml of oxLDL were 28.40 + 5.30% and 34.7 +/- 4.64%, with caspase-3 activity of 166. 01 +/- 16.44 and 263.74 +/- 46.62 pmol/(min x mg pro), respectively. The DNA electrophoresis showed typical ladders. With exposure to HDL (200 mixrog/ml), the above apoptosis rates dropped to 8.06 +/- 2.35% and 9.40 +/- 2.58% respectively. There were no apoptotic ladders while the caspase-3 activities were significantly reduced (67.73 +/- 14.83 and 111.26 +/- 27.13 pmol/(min x mg pro). CONCLUSIONS: HDL can significantly reduce the apoptosis of cultured endothelial cells induced by oxLDL. This effect may be mediated via suppression of caspase-3 activity.