Development of the system for prediction of drug-drug interactions in hepatobiliary transport process

1.我们成功地构建了分别表达人有机阴离子转运多肽（OATP）2和多药耐药相关蛋白2（MRP 2）以及大鼠Oatp 4和Mrp 2的人和大鼠双转染子。我们证实了OATP 2（Oatp 4）和MRP 2在基底侧和顶侧表达，这与肝脏中的生理极化表达模式一致。在该系统中，OATP 2（Oatp 4）/MRP 2双底物如雌二醇-17 β-葡萄糖醛酸苷和普伐他汀可以有效地从基底室转运到顶室，而不是其他方向。此外，大鼠体内肝脏清除率与大鼠双转染子的跨细胞清除率通过乘以一个比例因子得到良好的相关性，这表明该系统可能能够利用体内肝脏清除率的预测.为了评估临床情况下的副作用和药物相互作用，我们假设转运蛋白参与，我们分析了 ...更多信息 利用OATP 2表达系统和人冻存肝细胞研究环孢菌素A（CyA）和西立伐他汀（CER）之间的药物相互作用机制。结果，CyA有效抑制OATP 2介导的CER摄取，其抑制常数几乎与人肝细胞和CyA的临床未结合浓度相当。另一方面，CyA轻微抑制CER代谢酶。因此，我们认为，抑制OATP 2介导的肝摄取过程是其作用机制之一。为了研究双胍类降糖药严重副作用（乳酸酸中毒）的表达机制，我们利用人有机阳离子转运蛋白（OCT）1和2表达系统进行转运试验，以检查其在肝脏和肾脏中的转运机制。OCT 1和OCT 2可转运双胍类药物，提示OCT 1参与肝脏摄取，而OCT 2参与肾脏摄取，OCT 1介导的肝脏摄取可能是乳酸酸中毒的触发因素之一。少

1. We succeeded in the construction of human and rat double transfectants which express human organic anion transporting polypeptide(OATP) 2 and multidrug resistance asssociated protein 2 (MRP2), and rat Oatp4 and Mrp2, respectively. We confirmed that OATP2(Oatp4) and MRP2 expressed on the basal and apical side, which is consistent with the physiological polarized expression pattern in liver. In this system, OATP2(Oatp4)/MRP2 bisubstrates such as estradiol-17β-glucuronide and pravastatin can be transported from the basal to apical compartment efficiently, compared with other direction. Moreover, rat in vivo hepatic clearance was well correlated with transcellular clearance of rat double transfectant by multiplying a scaling factor, which suggested that this system may be able to utilize the prediction of in vivo hepatic clearance.2. To evaluate the side effects and drug-drug interactions in the clinical situations, which we hypothesized the involvement of transporters, we analyzed the … More mechanism of drug-drug interaction between cyclosporin A(CyA) and cerivastatin(CER) using OATP2 expression system and human cryopreserved hepatocytes. In result, CyA potently inhibited the OATP2-mediated CER uptake and its inhibition constant was almost comparable with that of human hepatocytes and clinical unbound concentration of CyA. On the other hand, CyA slightly inhibited CER metabolism by CYP enzymes. So we suggested that one of the interaction mechanism is inhibition of hepatic uptake process mediated by OATP2. To investigate the mechanism for the expression of severe side effects (lactic acidosis) of biguanides(antidiabetes drugs), we performed the transport assay using human organic cation transporter(OCT)1 and 2 expression system to check their transport mechanism in liver and kidney. Biguanides can be transported by OCT1 and OCT2, which suggested that OCT1 is involved in hepatic uptake, whereas OCT2 in renal uptake and that OCT1-mediated hepatic uptake may be one of the trigger for lactic acidosis. Less