The utility of HepG2 cells to identify direct mitochondrial dysfunction in the absence of cell death.
Drug-induced mitochondrial dysfunction has been hypothesized to be an important determining factor in the onset of drug-induced liver injury. It is essential to develop robust screens with which to identify drug-induced mitochondrial toxicity and to dissect its role in hepatotoxicity. In this study we have characterised a mechanistically refined HepG2 model, using a panel of selected hepatotoxicants and non-hepatotoxicants. We have demonstrated that acute metabolic modification, via glucose-deprivation over a 4 h period immediately prior to compound addition, is sufficient to allow the identification of drugs which induce mitochondrial dysfunction, in the absence of cell death over a short exposure (2-8 h) using a plate-based screen to measure cellular ATP content and cytotoxicity. These effects were verified by measuring changes in cellular respiration, via oxygen consumption and extracellular acidification rates. Overall, these studies demonstrate the utility of HepG2 cells for the identification of mitochondrial toxins which act directly on the electron transport chain and that the dual assessment of ATP content alongside cytotoxicity provides an enhanced mechanistic understanding of the causes of toxicity.
MRC Centre for Drug Safety Science, The Department of Clinical and Molecular Pharmacology, The University of Liverpool, Ashton Street, Liverpool L69 3GE, UK.
Laleh
L
Kamalian
MRC Centre for Drug Safety Science, The Department of Clinical and Molecular Pharmacology, The University of Liverpool, Ashton Street, Liverpool L69 3GE, UK. Electronic address: Amy.Chadwick@liverpool.ac.uk.
Amy E
AE
Chadwick
MRC Centre for Drug Safety Science, The Department of Clinical and Molecular Pharmacology, The University of Liverpool, Ashton Street, Liverpool L69 3GE, UK.
Mark
M
Bayliss
MRC Centre for Drug Safety Science, The Department of Clinical and Molecular Pharmacology, The University of Liverpool, Ashton Street, Liverpool L69 3GE, UK.
Neil S
NS
French
Pharmacokinetics Dynamics and Metabolism, Janssen Research and Development, Beerse, Belgium.
Mario
M
Monshouwer
Pharmacokinetics Dynamics and Metabolism, Janssen Research and Development, Beerse, Belgium.
Jan
J
Snoeys
MRC Centre for Drug Safety Science, The Department of Clinical and Molecular Pharmacology, The University of Liverpool, Ashton Street, Liverpool L69 3GE, UK.
B Kevin
BK
Park
D000255:Adenosine Triphosphate / Q000378:metabolism; D016923:Cell Death / Q000187:drug effects*; D002470:Cell Survival / Q000187:drug effects; D056486:Chemical and Drug Induced Liver Injury; D056945:Hep G2 Cells; D006801:Humans; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008930:Mitochondria, Liver / Q000187:drug effects*; D028361:Mitochondrial Diseases / Q000139:chemically induced* / Q000473:pathology; D010101:Oxygen Consumption / Q000187:drug effects
D000255:Adenosine Triphosphate; D007770:L-Lactate Dehydrogenase
Drug-induced liver injury; Dysfunction; HepG2; Mitochondria; Toxicity