牛磺酸和FK506对HepG2细胞胆固醇水平的影响

Effect of Taurine and FK506 on cholesterol levels in HepG2 cells

目的:以总胆固醇(Total cholesterol,TC)、游离胆固醇(Free cholesterol,FC)和胆固醇酯(Cholesterol ester,EC)为评价指标,探讨牛磺酸对FK506诱导肝癌细胞Hep G2细胞胆固醇水平代谢异常的影响。方法:首先建立损伤模型,加终浓度为1、5和10μg/m L的FK506,分别在培养24、48 h后测定细胞存活率以及胞内TC、FC和EC水平,确定FK506处理的终浓度;在此基础上,再添加终浓度为0.1、1、10和20 mmol/L的牛磺酸,分别培养24、48 h,测定细胞内TC、FC和EC水平。结果:培养24、48 h,5和10μg/m L FK506处理都使细胞TC、FC水平明显升高(p<0.05),EC水平没有明显变化,但10μg/m L FK506作用48 h时,细胞存活率显著下降到70%,因此确定FK506处理的终浓度为5μg/m L。在FK506(5μg/m L)预处理6 h后,0.1、1、10和20 mmol/L的牛磺酸作用24、48 h都可显著降低FK506诱导的细胞TC、FC水平升高(p<0.05),但作用24 h的效果优于48 h,以20 mmol/L作用24 h降胆固醇效果最佳。结论:FK506通过增加FC诱导Hep G2细胞胆固醇水平升高,而牛磺酸通过降低FC改善了细胞高胆固醇水平。

Objective ： The aim of present study was to investigate the effects of Taurine on abnormal cholesterol metabolism in HepG2 cells induced by tacrolimus with total cholesterol （TC）, free cholesterol （FC）and cholesterol ester （EC）as the evaluation indexes.Methods ： Cell survival rate and the levels of intracellular TC, FC, EC were detected after the cells were cultured for 24 and 48 h in DMEM supplemented with FKS06 at final concentrations of 1,5,10 μg/mL, respectively. The concentration of FK506 was determined which was used to test cholesterol lowering effect of Taurine.Then, Taurine was added to the DMEM with final concentration of 0.1,1,10 and 20 mmol/L after the cells were cultured with FK506 for 6 h and the levels of intracellular TC, FC and EC were detected after the turther incubation for 24 and 48 h. Results： The levels of intracellular TC and FC but not EC were significantly increased after the cells were cultured in the presence of 5 and 10 μg/mL FK506 for 24 h and 48 h （ p 〈 0.05 ） , but 10 μg/mL FK506 for 48 h resulted in cell survival rate decreased to 70% significantly.Therefore,5 μg/mL FK506 was selected as the treatment dose in the following experiments. With the FK506 （5 μg/mL）pretreatment for 6 h, Taurine （0.1,1,10 and 20 mmol/L） supplementation for 24 and 48 h could significantly reduced the evaluated TC,FC levels in cells induced by the FK506 （p 〈 0.05） , and showing a superior effect at 24 h than at 48 h. 20 mmol/L Taurine showed the best cholesterol lowing effect after 24 h treatment.Conclusion： FK506 increased the cholesterol level of HepG2 ceils by increasing FC,while Taurine reduced the high cholesterol level of cells by decreasing FC.