Abstract
Drug-induced intrahepatic cholestasis is characterized by cellular accumulation of bile acids (BAs), whose mechanisms remain poorly understood. The present study aimed to analyze early and progressive alterations of BA profiles induced by cyclosporine A, chlorpromazine, troglitazone, tolcapone, trovafloxacin, and tacrolimus after 4-hour, 24-hour, and 6-day treatments of differentiated HepaRG cells. In BA-free medium, the potent cholestatic drugs cyclosporine A, chlorpromazine, and troglitazone reduced endogenous BA synthesis after 24 hours, whereas the rarely cholestatic drugs tolcapone, trovafloxacin, and tacrolimus reduced BA synthesis only after 6 days. In the presence of physiologic serum BA concentrations, cyclosporine A, chlorpromazine, and troglitazone induced early and preferential cellular accumulation of unconjugated lithocholic, deoxycholic, and chenodeoxycholic acids that increased 8- to 12-fold and 47- to 50-fold after 24 hours and 6 days, respectively. Accumulation of these hydrophobic BAs resulted from strong inhibition of amidation, and in addition, for lithocholic acid reduction of its sulfoconjugation, and was associated with variable alterations of uptake and efflux transporters. Trovafloxacin also caused BA accumulation, especially after 6 days, whereas tolcapone and tacrolimus were still without effect. However, when exogenous BAs were added to the medium at cholestatic serum concentrations, a 6-day treatment with all drugs resulted in cellular BA accumulation with higher folds of chenodeoxycholic and lithocholic acids. At the tested concentration, tolcapone had the lowest effect. These results bring the first demonstration that major cholestatic drugs can cause preferential and progressive in vitro cellular accumulation of unconjugated toxic hydrophobic BAs and bring new insights into mechanisms involved in drug-induced cellular accumulation of toxic BAs.
Footnotes
- Received July 6, 2017.
- Accepted September 12, 2017.
↵1 A.S., A.B., and L.H. contributed equally to this work.
↵2 D.R. and A.G. are senior coauthors.
This work was partly supported by the European Community through the Innovative Medicines Initiative Joint Undertaking Mechanism-Based Integrated Systems for the Prediction of Drug-Induced Liver Injury (MIP-DILI) Project [grant agreement number 115336], resources of which are composed of financial contributions from the European Union’s Seventh Framework Programme [FP7/20072013] and in-kind contributions from companies of the European Pharmaceutical Industry Association. A.S. and A.B. were financially supported by the MIP-DILI Project.
↵This article has supplemental material available at dmd.aspetjournals.org.
- Copyright © 2017 by The American Society for Pharmacology and Experimental Therapeutics
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