Systems Microscopy Approaches In Unraveling And Predicting Drug-Induced Liver Injury (Dili)

The occurrence of drug-induced liver injury (DILI) after drug approval has often led to withdrawal from the market. Especially idiosyncratic DILI forms a major problem for pharmaceutical companies. Due to its independency of dose or duration of exposure, idiosyncratic DILI is considered as unpredictable. New in vitro test systems are now evoking to improve the prediction of DILI in the preclinical phase of drug development. Most conventional compound toxicity screening systems rely on single end-point assays most of which are based on relatively late-stage toxicity markers. When monitoring key events upstream in various adaptive stress signaling pathways combined in a single assay, the sensitivity to pick up hepatotoxic drugs will be increased while also mechanistic insight will be gained. Integrating with high-content imaging (HCI), time and high resolution single cell dynamics can be captured together with features for translocation between specific subcellular compartments. Efforts have been made to use specific dyes, antibodies or nanosensors in a multiplexed fashion using HCI, to assess multiple toxicity markers. However, these markers are still relatively downstream of toxicity signaling pathways which do not pinpoint to the molecular initiation event (MIE) of a drug. Here, we describe the application of a HepG2 BAC GFP reporter platform for the assessment of DILI liabilities by monitoring key components of adaptive stress pathways combining with HCI. Detailed insight in the regulation of these adaptive stress pathways during drug adversity can be reached by integrating these reporters with RNAi screening. Ultimately, this may lead to the recognition of novel biomarkers which can be used in the development of novel toxicity testing strategies.