title: Development of an in vitro renal epithelial disease state model for xenobiotic toxicity testing.
abstract: There is a growing impetus to develop more accurate, predictive and relevant in vitro models of renal xenobiotic exposure. As part of the EU-FP7, Predict-IV project, a major aim was to develop models that recapitulate not only normal tissue physiology but also aspects of disease conditions that exist as predisposing risk factors for xenobiotic toxicity. Hypoxia, as a common micro-environmental alteration associated with pathophysiology in renal disease, was investigated for its effect on the toxicity profile of a panel of 14 nephrotoxins, using the human proximal tubular epithelial RPTECT/TERT1 cell line. Changes in ATP, glutathione and resazurin reduction, after 14 days of daily repeat exposure, revealed a number of compounds, including adefovir dipivoxil with enhanced toxicity in hypoxia. We observed intracellular accumulation of adefovir in hypoxia and suggest decreases in the efflux transport proteins MRP4, MRP5, NHERF1 and NHERF3 as a possible explanation. MRP5 and NHERF3 were also down-regulated upon treatment with the HIF-1 activator, dimethyloxalylglycine. Interestingly, adefovir dependent gene expression shifted from alterations in cell cycle gene expression to an inflammatory response in hypoxia. The ability to investigate aspects of disease states and their influence on renal toxin handling is a key advantage of in vitro systems developed here. They also allow for detailed investigations into mechanisms of compound toxicity of potential importance for compromised tissue exposure.
authors.affiliation: University College Dublin, School of Medicine and Medical Science, Dublin, Ireland.
authors.forename: Daniel
authors.initials: D
authors.lastname: Crean
authors.affiliation: Institut fuer Toxikologie, Universitaet Wuerzburg, Versbacher Str. 9, 97078 Würzburg, Germany.
authors.forename: Patricia
authors.initials: P
authors.lastname: Bellwon
authors.affiliation: Division of Physiology, Department of Physiology and Medical Physics, Innsbruck Medical University, Innsbruck 6020, Austria.
authors.forename: Lydia
authors.initials: L
authors.lastname: Aschauer
authors.affiliation: Division of Physiology, Department of Physiology and Medical Physics, Innsbruck Medical University, Innsbruck 6020, Austria.
authors.forename: Alice
authors.initials: A
authors.lastname: Limonciel
authors.affiliation: Emergentec Biodevelopment GmbH, Vienna 1180, Austria.
authors.forename: Konrad
authors.initials: K
authors.lastname: Moenks
authors.affiliation: Merck KGaA, Merck Serono, Nonclinical Safety, Darmstadt 64293, Germany.
authors.forename: Philip
authors.initials: P
authors.lastname: Hewitt
authors.affiliation: Institut fuer Toxikologie, Universitaet Wuerzburg, Versbacher Str. 9, 97078 Würzburg, Germany.
authors.forename: Tobias
authors.initials: T
authors.lastname: Schmidt
authors.affiliation: Institut fuer Toxikologie, Universitaet Wuerzburg, Versbacher Str. 9, 97078 Würzburg, Germany.
authors.forename: Karin
authors.initials: K
authors.lastname: Herrgen
authors.affiliation: Institut fuer Toxikologie, Universitaet Wuerzburg, Versbacher Str. 9, 97078 Würzburg, Germany.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Dekant
authors.affiliation: Emergentec Biodevelopment GmbH, Vienna 1180, Austria.
authors.forename: Arno
authors.initials: A
authors.lastname: Lukas
authors.affiliation: Université de Technologie de Compiègne, Compiègne Cedex 60205, France.
authors.forename: Frederic
authors.initials: F
authors.lastname: Bois
authors.affiliation: Division of Physiology, Department of Physiology and Medical Physics, Innsbruck Medical University, Innsbruck 6020, Austria.
authors.forename: Anja
authors.initials: A
authors.lastname: Wilmes
authors.affiliation: Division of Physiology, Department of Physiology and Medical Physics, Innsbruck Medical University, Innsbruck 6020, Austria.
authors.forename: Paul
authors.initials: P
authors.lastname: Jennings
authors.affiliation: Centre for Radiation, Chemical and Environmental Hazards, Public Health England, Chilton, Didcot OX11 0RQ, UK. Electronic address: Martin.Leonard@phe.gov.uk.
authors.forename: Martin O
authors.initials: MO
authors.lastname: Leonard
mesh_terms: D000225:Adenine / Q000031:analogs & derivatives* / Q000633:toxicity; D002460:Cell Line; D004848:Epithelium / Q000187:drug effects* / Q000473:pathology*; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D000860:Hypoxia; D007674:Kidney Diseases / Q000139:chemically induced*; D007687:Kidney Tubules, Proximal / Q000166:cytology; D063065:Organophosphonates / Q000633:toxicity*; D010100:Oxygen; D040081:Protein Array Analysis; D018894:Reverse Transcriptase Inhibitors / Q000633:toxicity*; D018675:Toxicity Tests; D015262:Xenobiotics
chemical_list: D063065:Organophosphonates; D018894:Reverse Transcriptase Inhibitors; D015262:Xenobiotics; D000225:Adenine; D010100:Oxygen; C106812:adefovir dipivoxil
keywords: Chronic kidney disease; Hypoxia; Nephrotoxicity; Proximal tubule