葡萄糖和胰岛素调节三明治肝细胞中胆酸相关转运体表达及功能

Effects of glucose and insulin on expression and function of bile acid transporters in sandwich cultured rat hepatocytes

目的:测定葡萄糖、胰岛素等糖尿病血糖中的异常因素对体外培养肝细胞中胆汁酸相关转运体表达及功能的影响。方法:分离并用三明治法培养大鼠原代肝细胞,用不同浓度葡萄糖或胰岛素培养72h,使用胆盐类似物Cholyl-lysyl-fluo-rescein(CLF)进行摄取转运体钠/胆汁酸共转运体(Na+/bile acid cotransporter,ntcp)及外排转运体胆盐外排泵(Bilesalt export pump,bsep)转运体功能学实验,并用荧光定量PCR法测定胆汁酸相关转运体ntcp、bsep及调节胆汁酸代谢转运的核受体(Farnesoid X receptor,fxr)的mRNA表达变化。结果:高浓度的葡萄糖和胰岛素均使CLF的胆泡排泄减少。高糖和高胰岛素均能够降低ntcp的表达(3～4倍),增加bsep的表达(约2倍),高糖能够降低fxr的水平(约0.5倍),高胰岛素增加fxr的水平(约1.5倍)。结论:葡萄糖和胰岛素水平异常均会对胆汁酸相关转运体表达和功能造成影响;三明治原代肝细胞可用于胆酸和药物肝胆分布研究。

AIM： To explain the enhancement of bile acid excretion in diabetes from bile acid transporter perspective. METHODS： Primary rat hepatocytes were isolated and cultured in a sandwich configuration （SCRH）. Then hepato- cytes were cultured with different concentrations of glucose and insulin, and function of Na＋/bile acid cotransporter （ntcp） and bile salt export pump （bsep） were tested with Cholyl-lysyl-fluo- rescein （CLF） as a typical substrate, mRNA levels of ntcp, bsep and lipid regulating nuclear receptor fxr were determined with Real Time PCR. RESULTS：CLF biliary excretion was both decreased in high concentrations of glucose and insulin significantly. Both high concentrations ofglucose and insulin can decrease ntcp mRNA for 3-4 fold, but increase bsep mRNA for approxi- mately 2 fold. Levels of fxr mRNA was down regulated in high concentrations of glucose and up regulated in high concentrations of insulin. CONCLUSION： Abnormal glucose and insulin concentration have impacts on bile acid trans- porters in sandwich cultured rat hepatocytes. Sandwich cultured rat hepatocytes could offer a useful tool to explore hepatobiliary disposition of bile acid and drugs.