脂多糖对人脐血内皮祖细胞增殖及凋亡的影响

Effects of lipopolysaccharide on proliferation and apoptosis in human umbilical vein endothelial progenitor cells

目的:观察脂多糖(LPS)对体外培养的人脐血内皮祖细胞(EPCs)增殖及凋亡的影响。方法:以密度梯度离心法获取人脐血EPCs,体外诱导分化并鉴定。实验分对照组及不同浓度(2.5、5.0、10.0、20.0mmol/L)LPS组。四氮唑蓝(MTT)法检测细胞增殖能力,流式细胞仪测凋亡率及细胞周期。结果:110.0mmol/L组促进EPCs增殖,20.0 mmol/L组抑制EPCs增殖,差异有统计学意义(P<0.05),其余2组对EPCs增殖能力无显著影响,与对照组比差异无统计学意义(P>0.05)。220.0 mmol/L组促进EPCs凋亡,差异有统计学意义(P<0.05)。其余各组对EPCs凋亡率无明显影响,与对照组比较差异均无统计学意义(P>0.05)。310.0、20.0 mmol/L组影响细胞周期,10.0 mmol/L组G0/G1期细胞减少,S和G2/M期增加;20.0 mmol/L组发生S期阻滞,G2/M期细胞减少,与对照组比差异有统计学意义(P<0.05)。结论:LPS对EPCs增殖能力及凋亡的影响与其浓度有关,当浓度为20.0 mmol/L时抑制增殖并促进凋亡。

Objective：To investigate the effect of proliferation, apoptosis and cell cycle of lipopolysac-charide （LPS） on human umbilical vein endothelial progenitor cells. Methods：mononuclear cells were isolated from human umbilical cord blood. Mononuclearcells （MNCs） were isolated from human umbilical cord blood in vitro by Ficoll density gradient centrifugation. EPCs were characterized as adherent cells with double positive to DiI-acLDL uptake and lectin binding by direct lfuorescent staining under a laser scanning confocal microscope. There were ifve groups. The control group and four LPS concentration groups：2.5, 5.0, 10.0, 20.0 mmol/L. MTT was used to detect cell apoptosis and cell cycle. Results：①10.0 mmol/L LPS promotes proliferation of EPCs, while 20.0 mmol/L LPS inhibits the proliferation of endothelial progenitor cells （P〈0.05）.②20.0 mmol/L LPS promotes apoptosis of EPCs, compared with the control, the difference was signiifcant （P〈0.05）.③LPS at the concentration of 10.0 mmol/L reduces cells at G0/G1 phase and increases S and G2/M phase cells;20.0 mmol/L LPS induces EPCs blockade at S phase, G2/M phase cells decreased, compared with the control, the difference was signiifcant （P〈0.05）. Conclusion：10.0 mmol/L LPS promotes the proliferation of EPCs. 20.0 mmol/L LPS inhibits the proliferation and promotes apoptosis of EPCs.