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Parmentier C.,KaLy Cell | Couttet P.,Novartis | Wolf A.,Novartis | Zaccharias T.,Center Hospitalier Of Mulhouse | And 5 more authors.
Archives of Toxicology | Year: 2017

Primary human hepatocyte (PHH) sandwich cultures from five different donors were daily exposed to cyclosporine A (CsA), ibuprofen (IBU), chlorpromazine (CPZ), amiodarone (AMI) and paracetamol (APAP) at their respective Cmax (total) for short-term (1–3 days) and long-term treatment (14 days). Whole genome mRNA profiles (34,693 genes in total) were conducted using an Illumina microarray platform. The impact of compound treatments on gene signatures involved in liver differentiation, cholestasis and in bile acid homeostasis was evaluated. Notably, PHH from the five donors showed a highly comparable phenotype of terminally differentiated hepatocytes. As expected, PHH exposed to 100 µM APAP showed no signs of hepatotoxicity both after short- and long-term treatment. CsA at 0.7 µM, IBU at 100 µM, AMI at 2.5 µM and CPZ at 0.1–0.2 µM presented, in line with their cholestatic syndromes reported at therapeutic doses, transcriptomic signatures of cholestasis in PHH cultures; deregulation of genes involved in bile acid homeostasis further confirmed this finding. The strength of the cholestasis signature obtained after treatment with CsA, IBU and AMI could be directly related to the basal expression of the respective drug metabolizing enzymes in the various PHH cultures from different individuals. Our data show that the PHH model system combined with transcriptomics carries the future promise to identify individual gene expression profiles predictive of increased cholestasis risk. As the present work suggests possible correlation between mRNA levels of ADME relevant genes and a transcriptomic signature of cholestasis, particular focus on this research question could be the emphasis of additional data collection. © 2017 Springer-Verlag Berlin Heidelberg

Truisi G.L.,Merck KGaA | Truisi G.L.,Karlsruhe Institute of Technology | Consiglio E.D.,Instituto Superiore Of Sanita | Parmentier C.,KaLy Cell | And 12 more authors.
Toxicology Letters | Year: 2015

Common in vitro toxicity testing often neglects the fate and intracellular concentration of tested compounds, potentially limiting the predictability of in vitro results for in vivo extrapolation. We used in vitro long-term cultures of primary rat (PRH) and human hepatocytes (PHH) and HepaRG cells to characterise and model the biokinetic profile of ibuprofen (IBU) after single and daily repeated exposure (14 days) to two concentrations. A cross-model comparison was carried out at 100. μM, roughly corresponding to the human therapeutic plasma concentration. Our results showed that IBU uptake was rapid and a dynamic equilibrium was reached within 1 or 2 days. All three cell systems efficiently metabolised IBU. In terms of species-differences, our data mirrored known in vivo results. Although no bioaccumulation was observed, IBU intracellular concentration was higher in PRH due to a 10-fold lower metabolic clearance compared to the human-derived cells. In HepaRG cells, IBU metabolism increased over time, but was not related to the treatment. In PHH, a low CYP2C9 activity, the major IBU-metabolising CYP, led to an increased cytotoxicity. A high inter-individual variability was seen in PHH, whereas HepaRG cells and PRH were more reproducible models. Although the concentrations of IBU in PRH over time differed from the concentrations found in human cells under similar exposure conditions. © 2015 Elsevier Ireland Ltd.

Agency: European Commission | Branch: FP7 | Program: CP-IP | Phase: HEALTH-2007-1.3-1 | Award Amount: 16.43M | Year: 2008

The overall aim of Predict-IV is to develop strategies to improve the assessment of drug safety in the early stage of development and late discovery phase, by an intelligent combination of non animal-based test systems, cell biology, mechanistic toxicology and in-silico modelling, in a rapid and cost effective manner. A better prediction of the safety of an investigational compound in early development will be delivered. Margins-of-safety will be deduced and the data generated by the proposed approach may also identify early biomarkers of human toxicity for pharmaceuticals. The results obtained in Predict-IV will enable pharmaceutical companies to create a tailored testing strategy for early drug safety. The project will integrate new developments to improve and optimize cell culture models for toxicity testing and to characterize the dynamics and kinetics of cellular responses to toxic effects in vitro. The target organs most frequently affected by drug toxicity will be taken into account, namely liver and kidney. Moreover, predictive models for neurotoxicty are scarce and will be developed. For each target organ the most appropriate cell model will be used. The approach will be evaluated using a panel of drugs with well described toxicities and kinetics in animals and partly also in humans. This approach will be highly advantageous as it will allow a direct comparison between the in vivo to the in vitro data. A parallel analysis of several dynamic and kinetic models with a broad spectrum of endpoints should allow for the identification of several relevant biomarkers of toxicity. Inter-individual susceptibilities will be taken into account by integrating the polymorphisms of the major drug metabolizing enzymes and correlating the observed effects in the human cell models with their genotype. Environmental influences on cellular toxicity to these compounds will also be evaluated using hypoxic stress as a relevant test model.

PubMed | Karlsruhe Institute of Technology, University Utrecht, Merck KGaA, National Institute of Public Health and the Environment RIVM and 2 more.
Type: Journal Article | Journal: Toxicology in vitro : an international journal published in association with BIBRA | Year: 2015

Since drug induced liver injury is difficult to predict in animal models, more representative tests are needed to better evaluate these effects in humans. Existing in vitro systems hold great potential to detect hepatotoxicity of pharmaceuticals. In this study, the in vitro biokinetics of the model hepatotoxicant chlorpromazine (CPZ) were evaluated in three different liver cell systems after repeated exposure in order to incorporate repeated-dose testing into an in vitro assay. Primary rat and human hepatocytes, cultured in sandwich configuration and the human HepaRG cell line were treated daily with CPZ for 14 days. Samples were taken from medium, cells and well plastic at specific time points after the first and last exposure. The samples were analysed by HPLC-UV to determine the amount of CPZ in these samples. Based on cytotoxicity assays, the three models were tested at 1-2 M CPZ, while the primary rat hepatocytes and the HepaRG cell line were in addition exposed to a higher concentration of 15-20 M. Overall, the mass balance of CPZ decreased in the course of 24 h, indicating the metabolism of the compound within the cells. The largest decrease in parent compound was seen in the primary cultures; in the HepaRG cell cultures the mass balance only decreased to 50%. CPZ accumulated in the cells during the 14-day repeated exposure. Possible explanations for the accumulation of CPZ are a decrease in metabolism over time, inhibition of efflux transporters or binding to phospholipids. The biokinetics of CPZ differed between the three liver cell models and were influenced by specific cell properties as well as culture conditions. These results support the conclusion that in vitro biokinetics data are necessary to better interpret chemical-induced cytotoxicity data.

Muller C.,CNRS Chemistry of Complex Matter | Pekthong D.,KaLy Cell | Pekthong D.,Naresuan University | Alexandre E.,KaLy Cell | And 5 more authors.
Combinatorial Chemistry and High Throughput Screening | Year: 2015

In this paper we report quantitative structure-activity models linking in vivo Drug-Induced Liver Injury (DILI) of organic molecules with some parameters both measured experimentally in vitro and calculated theoretically from the molecular structure. At the first step, a small database containing information of DILI in humans was created and annotated by experimentally observed information concerning hepatotoxic effects. Thus, for each compound a binary annotation "yes/no" was applied to DILI and seven endpoints causing different liver pathologies in humans: Cholestasis (CH), Oxidative Stress (OS), Mitochondrial injury (MT), Cirrhosis and Steatosis (CS), Hepatitis (HS), Hepatocellular (HC), and Reactive Metabolite (RM). Different machine-learning methods were used to build classification models linking DILI with molecular structure: Support Vector Machines, Artificial Neural Networks and Random Forests. Three types of models were developed: (i) involving molecular descriptors calculated directly from chemical structure, (ii) involving selected endpoints as "biological" descriptors, and (iii) involving both types of descriptors. It has been found that the models based solely on molecular descriptors have much weaker prediction performance than those involving in vivo measured endpoints. Taking into account difficulties in obtaining of in vivo data, at the validation stage we used instead five endpoints (CH, CS, HC, MT and OS) measured in vitro in human hepatocyte cultures. The models involving either some of experimental in vitro endpoints or their combination with theoretically calculated ones correctly predict DILI for 9 out of 10 reference compounds of the external test set. This opens an interesting perspective to use for DILI predictions a combination of theoretically calculated parameters and measured in vitro biological data. © 2015 Bentham Science Publishers.

Gerin B.,UCB Pharma | Dell'aiera S.,UCB Pharma | Richert L.,Kaly Cell | Smith S.,UCB Pharma | Chanteux H.,UCB Pharma
Xenobiotica | Year: 2013

1. A fast, straightforward and cost-effective assay was validated for the assessment of CYP induction in cryopreserved human hepatocytes cultured in 48-well plates. The cocktail strategy (in situ incubation) was used to assess the induction of CYP1A2, CYP2B6, CYP2C9 and CYP3A4 by using the recommended probe substrate, i.e. phenacetin, bupropion, diclofenac and midazolam, respectively. 2. Cryopreserved human hepatocytes were treated for 72 h with prototypical reference inducers, β-naphthoflavone (25 μM), phenobarbital (500 μM) and rifampicin (10 μM) as positive controls for CYP induction. The use of a cocktail strategy has been validated and compared to the classical approach (single incubation). The need of using phase II inhibitor (salicylamide) in CYP induction assay was also investigated. 3. By using three different batches of cryopreserved human hepatocytes and our conditions of incubations, we showed that there was no relevant drug-drug interaction using the cocktail strategy. The same conclusions were observed when a broad range of enzyme activity has to be assessed (wide range of reference inducers, i.e. EC50-Emax experiment). In addition, the interassay reproducibility assessment showed that the day-to-day variability was minimal. 4. In summary, the study showed that the conditions used (probe substrates, concentration of probe substrate and time of incubation) for the cocktail approach were appropriate for investigations of CYP induction potential of new chemical entities. In addition, it was also clear that the use of salicylamide in the incubation media was not mandatory and could generate drug-drug interactions. For this reason, we recommend to not use salicylamide in CYP induction assay. © 2013 Informa UK, Ltd.

PubMed | Catholic University of Leuven and KaLy Cell
Type: Journal Article | Journal: Toxicology and applied pharmacology | Year: 2013

Early detection of drug-induced cholestasis remains a challenge during drug development. We have developed and validated a biorelevant sandwich-cultured hepatocytes- (SCH) based model that can identify compounds causing cholestasis by altering bile acid disposition. Human and rat SCH were exposed (24-48h) to known cholestatic and/or hepatotoxic compounds, in the presence or in the absence of a concentrated mixture of bile acids (BAs). Urea assay was used to assess (compromised) hepatocyte functionality at the end of the incubations. The cholestatic potential of the compounds was expressed by calculating a drug-induced cholestasis index (DICI), reflecting the relative residual urea formation by hepatocytes co-incubated with BAs and test compound as compared to hepatocytes treated with test compound alone. Compounds with clinical reports of cholestasis, including cyclosporin A, troglitazone, chlorpromazine, bosentan, ticlopidine, ritonavir, and midecamycin showed enhanced toxicity in the presence of BAs (DICI0.8) for at least one of the tested concentrations. In contrast, the in vitro toxicity of compounds causing hepatotoxicity by other mechanisms (including diclofenac, valproic acid, amiodarone and acetaminophen), remained unchanged in the presence of BAs. A safety margin (SM) for drug-induced cholestasis was calculated as the ratio of lowest in vitro concentration for which was DICI0.8, to the reported mean peak therapeutic plasma concentration. SM values obtained in human SCH correlated well with reported % incidence of clinical drug-induced cholestasis, while no correlation was observed in rat SCH. This in vitro model enables early identification of drug candidates causing cholestasis by disturbed BA handling.

PubMed | KaLy Cell
Type: Comparative Study | Journal: Drug metabolism and disposition: the biological fate of chemicals | Year: 2011

Benzyloxyresorufin-O-dealkylation (BROD) is usually used as a marker of cytochrome P450 (P450) 2B1 in rat. However, some reports show that CYP1A2 is also highly implicated. The purpose of the present study was to establish bupropion (BUP) hydroxylation, but not BROD, as a selective in vitro marker of CYP2B1 catalytic activity. IC(50) for BROD and BUP hydroxylation were equivalent (40.8 4.6 and 41.8 3.4 M, respectively) when using liver microsomes from -naphthoflavone-pretreated rats in the presence of metyrapone (CYP2B1 inhibitor). When using the same microsomes in the presence of CYP1A1/2-selective inhibitor -naphthoflavone, we found an IC(50) of 2.5 10(-3) 0.8 10(-3) M for BROD and >100 M for BUP hydroxylation. These results suggest that CYP2B1 is similarly involved in both activities, whereas CYP1A2 is involved in BROD activity but not in BUP hydroxylation. BUP hydroxylation was assessed in microsomes from baculovirus-infected insect cells coexpressing NADPH-P450 oxidoreductase, and 14 rat P450s and kinetic parameters (K(m) and V(max)) were determined. BUP hydroxylation was predominantly catalyzed by CYP2B1 (75% of total hydroxybupropion formation), low activity was detected with CYP2E1 and CYP2C11 (10.9 and 8.7% of total hydroxybupropion, respectively), and activity was almost undetectable with the other P450 isoforms at saturating substrate concentrations (2500 M), thereby validating the use of BUP as a diagnostic in vitro marker of CYP2B1 catalytic activity in rat.

PubMed | Center hospitalier Emile Muller, Catholic University of Leuven, University of Franche Comte and KaLy Cell
Type: | Journal: Toxicology in vitro : an international journal published in association with BIBRA | Year: 2016

Drug-induced cholestasis (DIC) is recognized as one of the prime mechanisms for DILI. Hence, earlier detection of drug candidates with cholestatic signature is crucial. Recently, we introduced an in vitro model for DIC and evaluated its performance with several cholestatic drugs. We presently expand on the validation of this model by 14 training compounds (TCs) of the EU-EFPIA IMI project MIP-DILI. Several batches of human hepatocytes in sandwich-culture were qualified for DIC assessment by verifying the bile acid-dependent increase in sensitivity to the toxic effects of cyclosporin A. The cholestatic potential of the TCs was expressed by determining the drug-induced cholestasis index (DICI). A safety margin (SM) was calculated as the ratio of the lowest TC concentration with a DICI0.80 to the Cmax,total. Nefazodone, bosentan, perhexiline and troglitazone were flagged for cholestasis (SM<30). The hepatotoxic (but non-cholestatic) compounds, amiodarone, diclofenac, fialuridine and ximelagatran, and all non-hepatotoxic compounds were cleared as safe for DIC. Tolcapone and paracetamol yielded DICI-based SM values equal to or higher than those based on cytotoxicity, thus excluding DIC as a DILI mechanism. This hepatocyte-based in vitro assay provides a unique tool for early and reliable identification of drug candidates with cholestasis risk.

PubMed | KaLy Cell
Type: Journal Article | Journal: Xenobiotica; the fate of foreign compounds in biological systems | Year: 2012

1.The aim of the present study was to assess the stability of cryopreserved human hepatocytes over 5 years and to explore experimental condition-related variables such as seeding density, culture matrix and medium, start and duration of treatment that could potentially affect the quality of cultures and their response to cytochrome P450 (CYP) inducers. 2.63/125 batches of cryopreserved human hepatocytes were plateable after thawing. Of those, 17 batches showed reproducible recovery, viability and plateability (less than 5% intra-batch variability) up to 5 years. When cultured in collagen home-coated 48-well plates at a seeding density allowing 70% confluence, cryopreserved human hepatocytes display activities equivalent to fresh counterparts. Their response to CYP inducers is maximal and equivalent to fresh counterpart for an incubation of 72 h starting at Day 2 or Day 3 after plating when cultured in modified Hepatocyte Maintenance Medium (HMM). The number of cryopreserved human hepatocytes can be further reduced by using a cocktail of CYP substrates for the assessment of their inducibility. 3.Experimental condition-related variables, such as seeding density, culture matrix and medium, start and duration of treatment, affecting the response of plateable thawed cryopreserved human hepatocytes to cytochrome P450 inducers can be reduced by optimizing critical steps of the protocols.

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