Zhu Qing, Xia Haiyan, Xia Cindy Q, Yang Qian, Doshi Utkarsh, Li Albert P, Liao Mingxiang
Takeda Pharmaceuticals International Co. 40 Landsdowne St. Cambridge, MA 02139, USA.
Drug Metab Lett. 2014 Jul;7(2):117-25. doi: 10.2174/1872312808666140317153311.
Human hepatic organic anion-transporting polypeptides (OATPs), including OATP1B1, 1B3, and 2B1, are expressed at the basolateral membrane of hepatocytes and mediate the uptake of a variety of compounds from blood into hepatocytes. The liver-specific OATPs are increasingly recognized as playing important roles in the pharmacokinetic (PK) of many drugs and thus, involved in the clinically significant drug-drug interactions (DDIs). However, the evaluation of the specific roles of individual OATPs in hepatocytes is challenging because of the lack of selective inhibitors and probe substrates for each OATP member. In the present study, the uptake activity of OATP1B3 was examined in human hepatocytes cultured up to 14 days using an in vitro uptake assay. The results showed that OATP-mediated uptake of rosuvastatin, a substrate for OATPs declined substantially in cultured human hepatocytes. In contrast, the uptake of OATP1B3-selective substrate telmisartan was not measureable at earlier culture periods, but became detectable on Day 7 and showed culture duration-dependent changes from Day 7 to 14. Quantitative polymerase chain reaction (qPCR) analyses illustrated that the OATP functional change was not correlated with messenger ribonucleic acid (mRNA) expression alteration in hepatocytes cultured for 3 hours or 7 days. The OATP1B3-mediated telmisartan uptake was also culture medium- and donor-dependent, and only observed in 3 of 5 lots of hepatocytes cultured in 2 of 3 media tested. These results show that using human hepatocytes cultured in certain conditions may provide an excellent addition to transfected cell lines as a way to distinguish OATP1B3 from other hepatic OATP family members, such as OATP1B1, to provide more understanding of OATP-mediated clinical DDI.
人类肝脏有机阴离子转运多肽（OATP），包括OATP1B1、1B3和2B1，表达于肝细胞的基底外侧膜，介导多种化合物从血液摄取进入肝细胞。肝脏特异性OATP越来越被认为在许多药物的药代动力学（PK）中发挥重要作用，因此，参与了具有临床意义的药物相互作用（DDI）。然而，由于缺乏针对每个OATP成员的选择性抑制剂和探针底物，评估单个OATP在肝细胞中的具体作用具有挑战性。在本研究中，使用体外摄取试验检测了培养至14天的人肝细胞中OATP1B3的摄取活性。结果表明，OATP介导的瑞舒伐他汀（一种OATP底物）摄取在培养的人肝细胞中显著下降。相比之下，OATP1B3选择性底物替米沙坦的摄取在培养早期无法测量，但在第7天变得可检测到，并在第7天至14天显示出培养时间依赖性变化。定量聚合酶链反应（qPCR）分析表明，OATP功能变化与培养3小时或7天的肝细胞中信使核糖核酸（mRNA）表达改变无关。OATP1B3介导的替米沙坦摄取也依赖于培养基和供体，并且仅在测试的3种培养基中的2种培养基中培养的5批肝细胞中的3批中观察到。这些结果表明，在特定条件下培养人肝细胞可能是对转染细胞系的一种很好补充，作为区分OATP1B3与其他肝脏OATP家族成员（如OATP1B1）的一种方法，以更深入了解OATP介导的临床DDI。
