title: Kinetics and dynamics of cyclosporine A in three hepatic cell culture systems.
abstract: In vitro experiments have a high potential to improve current chemical safety assessment and reduce the number of animals used. However, most studies conduct hazard assessment alone, largely ignoring exposure and kinetic parameters. Therefore, in this study the kinetics of cyclosporine A (CsA) and the dynamics of CsA-induced cyclophilin B (Cyp-B) secretion were investigated in three widely used hepatic in vitro models: primary rat hepatocytes (PRH), primary human hepatocytes (PHH) and HepaRG cells. Cells were exposed daily to CsA for up to 14 days. CsA in cells and culture media was quantified by LC-MS/MS and used for pharmacokinetic modeling. Cyp-B was quantified by western blot analysis in cells and media. All cell systems took up CsA rapidly from the medium after initial exposure and all showed a time- and concentration-dependent Cyp-B cellular depletion and extracellular secretion. Only in PRH an accumulation of CsA over 14 days repeated exposure was observed. Donor-specific effects in CsA clearance were observed in the PHH model and both PHH and HepaRG cells significantly metabolized CsA, with no bioaccumulation being observed after repeated exposure. The developed kinetic models are described in detail and show that all models under-predict the in vivo hepatic clearance of CsA, but to different extents with 27-, 24- and 2-fold for PRH, PHH and HepaRG cells, respectively. This study highlights the need for more attention to kinetics in in vitro studies.
authors.affiliation: Department of Toxicology, University of Wuerzburg, Wuerzburg, Germany. Electronic address: patricia.bellwon@uni-wuerzburg.de.
authors.forename: P
authors.initials: P
authors.lastname: Bellwon
authors.affiliation: Non-Clinical Safety, Merck Serono, Merck KGaA, Darmstadt, Germany; Institut für Angewandte Biowissenschaften, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany.
authors.forename: G L
authors.initials: GL
authors.lastname: Truisi
authors.affiliation: INERIS, DRC/VIVA/METO, Verneuil en Halatte, France.
authors.forename: F Y
authors.initials: FY
authors.lastname: Bois
authors.affiliation: Division of Physiology, Department of Physiology and Medical Physics, Medical University of Innsbruck, Innsbruck 6020, Austria.
authors.forename: A
authors.initials: A
authors.lastname: Wilmes
authors.affiliation: Department of Toxicology, University of Wuerzburg, Wuerzburg, Germany.
authors.forename: T
authors.initials: T
authors.lastname: Schmidt
authors.affiliation: INSERM, UMR991, Université de Rennes 1, Rennes, France.
authors.forename: C C
authors.initials: CC
authors.lastname: Savary
authors.affiliation: KaLy-Cell, Plobsheim, France.
authors.forename: C
authors.initials: C
authors.lastname: Parmentier
authors.affiliation: Non-Clinical Safety, Merck Serono, Merck KGaA, Darmstadt, Germany.
authors.forename: P G
authors.initials: PG
authors.lastname: Hewitt
authors.affiliation: Department of Toxicology, University of Wuerzburg, Wuerzburg, Germany.
authors.forename: O
authors.initials: O
authors.lastname: Schmal
authors.affiliation: INSERM, UMR991, Université de Rennes 1, Rennes, France.
authors.forename: R
authors.initials: R
authors.lastname: Josse
authors.affiliation: KaLy-Cell, Plobsheim, France; Université de Franche-Comté, Besançon, France.
authors.forename: L
authors.initials: L
authors.lastname: Richert
authors.affiliation: INSERM, UMR991, Université de Rennes 1, Rennes, France.
authors.forename: A
authors.initials: A
authors.lastname: Guillouzo
authors.affiliation: Non-Clinical Safety, Merck Serono, Merck KGaA, Darmstadt, Germany; Department of Food Chemistry and Toxicology, Technische Universität Kaiserslautern, Kaiserslautern, Germany.
authors.forename: S O
authors.initials: SO
authors.lastname: Mueller
authors.affiliation: Division of Physiology, Department of Physiology and Medical Physics, Medical University of Innsbruck, Innsbruck 6020, Austria.
authors.forename: P
authors.initials: P
authors.lastname: Jennings
authors.affiliation: Mechanism of Toxicity Unit, Environment and Primary Prevention Department, Istituto Superiore di Sanità, Rome, Italy.
authors.forename: E
authors.initials: E
authors.lastname: Testai
authors.affiliation: Department of Toxicology, University of Wuerzburg, Wuerzburg, Germany.
authors.forename: W
authors.initials: W
authors.lastname: Dekant
mesh_terms: D000328:Adult; D000368:Aged; D000818:Animals; D002478:Cells, Cultured; D016572:Cyclosporine / Q000493:pharmacokinetics*; D022781:Hepatocytes / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D051381:Rats
chemical_list: D016572:Cyclosporine
keywords: Cyclophilin B depletion; Cyclosporine A; Hepatic in vitro models; Kinetics; Pharmacokinetic modeling