Quantitative analysis of drugs induced BSEP inhibition and cholestatic hepatotoxicity

药物性肝损伤（DILI）是候选化合物退出药物测试和药物退出临床使用的主要原因。在肝损伤的多种机制中，胆汁酸（BAs）在肝细胞内的积累被认为是DILI发生的主要机制。虽然胆汁盐输出泵（BSEP）功能障碍被认为是DILI的易感因素，但药物性BSEP功能障碍与ba依赖性肝毒性之间的关系尚不清楚。此外，很少有方法可以系统和定量地评估ba依赖性DILI。本研究旨在利用三明治培养肝细胞（SCHs）构建DILI模型。SCHs可以用来评估小管转运蛋白（如BSEP）的功能和代谢酶的活性。本研究研究了25种测试化合物对大鼠ba依赖性细胞毒性的影响。结果，在ba存在的情况下，11种测试化合物在肝细胞中观察到ba依赖性毒性，而在不存在ba的情况下，肝细胞没有观察到毒性迹象。在这11种化合物中，有9种是已知的BSEP抑制剂。此外，对于某些化合物，在与1-氨基苯并三唑（一种细胞色素P450 （CYP450）介导的药物代谢的非选择性抑制剂）共同处理的SCHs中观察到ba依赖性毒性的严重程度增加。这些结果表明，基于sch的模型可能有助于评估ba依赖性DILI，包括药物代谢和BSEP抑制对肝损伤的影响。

Drug-induced liver injury (DILI) is a major reason for the dropout of candidate compounds from drug testing and the withdrawal of pharmaceuticals from clinical use. Among the various mechanisms of liver injury, the accumulation of bile acids (BAs) within hepatocytes is thought to be a primary mechanism for the development of DILI. Although bile salt export pump (BSEP) dysfunction is considered a susceptibility factor for DILI, little is known about the relationship between drug-induced BSEP dysfunction and BA-dependent hepatotoxicity. Furthermore, few methods are at hand for the systematic and quantitative evaluation of BA-dependent DILI. This study aimed to construct a model of DILI by employing sandwich-cultured hepatocytes (SCHs). SCHs can be used to assess functions of canalicular transporters such as BSEP and the activity of metabolic enzymes. Here, the impact of 25 test compounds was investigated on BA-dependent cytotoxicity in SCHs. As a result, BA-dependent toxicity was observed for 11 test compounds in SCHs treated in the presence of BAs, while no signs of toxicity were observed for SCHs treated in the absence of BAs. Of the 11 compounds, nine were known BSEP inhibitors. Moreover, for some compounds, an increase in the severity of BA-dependent toxicity was observed in SCHs that were co-treated with 1-aminobenzotriazole, a non-selective inhibitor of cytochrome P450 (CYP450)-mediated drug metabolism. These results indicate that the SCH-based model is likely to prove useful for the evaluation of BA-dependent DILI, including the effects of drug metabolism and BSEP inhibition on liver injury.