芒果苷上调HepG2细胞膜蛋白MRP3和核受体PXR、CPF表达

Mangiferin up-regulates expression of membrane protein MRP3 and nuclear receptors PXR and CPF in HepG2 cells

目的体外HepG2细胞培养观察芒果苷(mangiferin)对多耐药相关蛋白3(multidrug resistance-associate protein 3,MRP3)和核受体孕烷X受体(pregnane X receptor,PXR)、CYP7A启动子结合因子(CYP7A promoter-binding factor,CPF)表达的影响。方法用芒果苷刺激HepG2细胞72 h后,分别抽提细胞RNA、膜蛋白及核蛋白,采用半定量RT-PCR和蛋白免疫印迹检测膜转运蛋白MRP3和核受体PXR、CPF在转录与蛋白水平的表达变化。熊脱氧胆酸(ursode-oxycholic acid,UDCA)处理的HepG2细胞作为阳性对照、DMSO处理细胞为阴性对照。结果芒果苷可显著刺激HepG2细胞膜转运蛋白MRP3的mRNA(比阴性对照组高3.0倍,P<0.05)和蛋白(比阴性对照组高3.3倍,P<0.05)表达,其作用强于UDCA。芒果苷也可明显上调核受体PXR[mRNA水平增高1.7倍(P<0.05),蛋白水平增高3.7倍(P<0.01)]、CPF[mRNA水平增高2.1倍(P<0.05),蛋白水平增高4.9倍(P<0.05)]的表达。结论芒果苷刺激肝癌细胞HepG2细胞膜转运蛋白MRP3的表达上调可能与核受体PXR、CPF途径相关。

Objective To observe the effect of mangiferin on expressions of multidrug resistance-associated protein 3（MRP3）,nuclear pregnane X receptor（PXR）,and CYP7A promoter-binding factor（CPF） in HepG2 cells.Methods Total RNA and membrane or nuclear protein were extracted from HepG2 cells 72 h after treated with mangiferin.Expressions of PXR and CPF at transcription and protein levels were detected by semi-quantitative RT PCR and Western blotting,respectively.HepG2 cells treated with ursodeoxycholic acid（UDCA） and DMSO served as positive and negative controls,respectively.Results Mangiferin could significantly up-regulate the mRNA and protein expression of MRP3 in HepG2 cells.The mRNA and protein expression levels of MRP3 were 3-fold and 3.3-fold higher,respectively,in positive controls than in negative controls（P0.05）.The effect of mangiferin was stronger than that of UDCA on the expression of MRP3（P0.05）.Mangiferin up-regulated the expression levels of PXR and CPF（1.7-fold）,mRNA of MRP3（3.7-fold）,CPF（2.1-fold）,and protein of MRP3（4.9-fold）,respectively,in HepG2 cells（P0.05）.Conclusion Mangiferin can up-regulate the expression of MRP3 in HepG2 cells,which may be related with PXR and PXR.