Up-Regulation of CYP2C19 Expression by BuChang NaoXinTong via PXR Activation in HepG2 Cells.
Up-Regulation of CYP2C19 Expression by BuChang NaoXinTong via PXR Activation in HepG2 Cells.
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步长脑心通通过 PXR 激活上调 HepG2 细胞中 CYP2C19 的表达
DOI：
10.1371/journal.pone.0160285
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发表时间：
2016
期刊：
影响因子：
3.7
通讯作者：
Chen H
中科院分区：
文献类型：
--
作者：
Sun H;Lou XY;Wu XY;Wang H;Qu Q;Tan SL;Ruan JS;Qu J;Chen H
背景细胞色素P450 2C19是一种重要的药物代谢酶，负责质子泵抑制剂、血小板聚集抑制剂和抗抑郁药等多种药物的生物转化。既往研究表明步长脑心通胶囊在体外可提高细胞色素P450 2 C19的代谢活性，在体内可增强氯吡格雷的抗血小板作用。然而，其潜在的分子机制仍不清楚。在这项研究中，我们研究了孕烷X受体(PXR)是否在NXT介导的CYP2C19表达调节中发挥作用。方法采用荧光素酶活性测定、实时定量聚合酶链式反应(QPCR)、Western blotting和细胞代谢活性实验等方法，研究NXT对细胞色素P450 2 C19启动子活性、mRNA/蛋白表达和代谢活性的调节作用。结果NXT与PXR共转染人肝癌细胞株HepG2后，明显增强了细胞色素PXC19启动子的活性。PXR反应元件的突变消除了NXT对CYP2C19启动子转录的诱导作用。此外，NXT(15 0和2 5 0μg/m L)还可显著上调PXR基因转染人肝癌细胞的内源性细胞色素P4 2 C19m RNA和蛋白水平。相应地，NXT可显著增强PXR基因转导的HepG2细胞中细胞色素P2C19的催化活性。结论NXT可通过激活PXR诱导细胞内细胞色素P2C19的表达。
Background Cytochrome P450 2C19 (CYP2C19) is an important drug-metabolizing enzyme (DME), which is responsible for the biotransformation of several kinds of drugs such as proton pump inhibitors, platelet aggregation inhibitors and antidepressants. Previous studies showed that Buchang NaoXinTong capsules (NXT) increased the CYP2C19 metabolic activity in vitro and enhanced the antiplatelet effect of clopidogrel in vivo. However, the underlying molecular mechanism remained unclear. In the present study, we examined whether Pregnane X receptor (PXR) plays a role in NXT-mediated regulation of CYP2C19 expression. Methods We applied luciferase assays, real-time quantitative PCR (qPCR), Western blotting and cell-based analysis of metabolic activity experiments to investigate the NXT regulatory effects on the CYP2C19 promoter activity, the mRNA/ protein expression and the metabolic activity. Results Our results demonstrated that NXT significantly increased the CYP2C19 promoter activity when co-transfected with PXR in HepG2 cells. Mutations in PXR responsive element abolished the NXT inductive effects on the CYP2C19 promoter transcription. Additionally, NXT incubation (150 and 250μg/mL) also markedly up-regulated endogenous CYP2C19 mRNA and protein levels in PXR-transfected HepG2 cells. Correspondingly, NXT leaded to a significant enhancement of the CYP2C19 catalytic activity in PXR-transfected HepG2 cells. Conclusion In summary, this is the first study to suggest that NXT could induce CYP2C19 expression via PXR activation.