Division of Pharmacotherapy and Experimental Therapeutics, UNC Eshelman School of Pharmacy (K.K., B.C.F., I.N., K.Y., K.L.R.B.), and Biostatistics Department, School of Public Health (P.W.St.), University of North Carolina at Chapel Hill, Chapel Hill, North Carolina; Department of Pharmacy, Uppsala University, Uppsala, Sweden (I.N.); Center for Human Genome Variation, Duke University Medical Center, Durham, North Carolina (T.J.U.); and Department of Pharmaceutical Sciences, University of Maryland, Baltimore, Maryland (P.W.Sw.).
Drug Metab Dispos. 2014 Apr;42(4):665-74. doi: 10.1124/dmd.113.054304. Epub 2013 Oct 23.
Impaired hepatic bile acid export may contribute to development of cholestatic drug-induced liver injury (DILI). The multidrug resistance-associated proteins (MRP) 3 and 4 are postulated to be compensatory hepatic basolateral bile acid efflux transporters when biliary excretion by the bile salt export pump (BSEP) is impaired. BSEP inhibition is a risk factor for cholestatic DILI. This study aimed to characterize the relationship between MRP3, MRP4, and BSEP inhibition and cholestatic potential of drugs. The inhibitory effect of 88 drugs (100 μM) on MRP3- and MRP4-mediated substrate transport was measured in membrane vesicles. Drugs selected for investigation included 50 BSEP non-inhibitors (24 non-cholestatic; 26 cholestatic) and 38 BSEP inhibitors (16 non-cholestatic; 22 cholestatic). MRP4 inhibition was associated with an increased risk of cholestatic potential among BSEP non-inhibitors. In this group, for each 1% increase in MRP4 inhibition, the odds of the drug being cholestatic increased by 3.1%. Using an inhibition cutoff of 21%, which predicted a 50% chance of cholestasis, 62% of cholestatic drugs inhibited MRP4 (P < 0.05); in contrast, only 17% of non-cholestatic drugs were MRP4 inhibitors. Among BSEP inhibitors, MRP4 inhibition did not provide additional predictive value of cholestatic potential; almost all BSEP inhibitors were also MRP4 inhibitors. Inclusion of pharmacokinetic predictor variables (e.g., maximal unbound concentration in plasma) in addition to percent MRP4 inhibition in logistic regression models did not improve cholestasis prediction. Association of cholestasis with percent MRP3 inhibition was not statistically significant, regardless of BSEP-inhibition status. Inhibition of MRP4, in addition to BSEP, may be a risk factor for the development of cholestatic DILI.
胆汁酸转运蛋白 3 和 4 可能是胆汁盐输出泵(BSEP)功能障碍时的补偿性肝基底外侧胆汁酸外排转运体。BSEP 抑制是胆甾型药物性肝损伤(DILI)的一个风险因素。本研究旨在研究 MRP3、MRP4 和 BSEP 抑制与药物胆甾型潜力之间的关系。采用膜囊泡法测定 88 种药物(100 μM)对 MRP3 和 MRP4 介导的底物转运的抑制作用。选择用于研究的药物包括 50 种 BSEP 非抑制剂(24 种非胆甾型;26 种胆甾型)和 38 种 BSEP 抑制剂(16 种非胆甾型;22 种胆甾型)。MRP4 抑制与 BSEP 非抑制剂的胆甾型潜力增加相关。在该组中,MRP4 抑制增加 1%,药物胆甾型的可能性增加 3.1%。使用预测胆甾型发生概率为 50%的抑制率截断值 21%,62%的胆甾型药物抑制了 MRP4(P<0.05);相比之下,只有 17%的非胆甾型药物是 MRP4 抑制剂。在 BSEP 抑制剂中,MRP4 抑制对胆甾型潜力没有提供额外的预测价值;几乎所有的 BSEP 抑制剂也是 MRP4 抑制剂。在逻辑回归模型中,除了 MRP4 抑制率外,加入药代动力学预测变量(例如,血浆中最大未结合浓度)并不能改善胆甾型的预测。无论 BSEP 抑制状态如何,MRP3 抑制与胆甾型的关联均无统计学意义。除了 BSEP 抑制外,MRP4 抑制可能是胆甾型 DILI 发生的一个风险因素。