Abstract
New approach methodologies (NAMs) are gaining traction for drug toxicity screening. In recent years, human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) and hiPSC-derived sensory neurons have found greater utility for in vitro toxicity screens. They are a scalable, physiologically relevant model system, providing an ethical alternative to animal testing. Here, we show the application of commercially available hiPSC-derived cells on multiwell plate formats to assess drug response and toxicity.
Contractility assessment using the FLEXcyte™ 96 system showed that chamber-specific hiPSC-derived cardiomyocytes exhibited different baseline contractility waveforms. Atrial cardiomyocytes had a faster beat rate, shorter beat-width and lower contractile amplitude when compared to ventricular cardiomyocytes. In addition, atrial and ventricular cardiomyocytes demonstrated varying responses to the compounds tested. Of note, the Ca2+ agonist S-Bay K8644 had opposing effects on chamber-specific human iPSC-CMs, with atrial cardiomyocytes exhibiting transiently reduced beat rate, increased contractile force and longer beat duration whereas ventricular cardiomyocytes exhibited increased beat rate, decreased contractile force and shorter beat duration.
Neurite outgrowth assessment of hiPSC-derived sensory neurons using the Incucyte® S3 demonstrated that effective cell masking could be achieved using the NeuroTrack module, albeit with higher seeding densities reducing the accuracy of neurite tracking. Paclitaxel treatment inhibited neurite outgrowth, confirming assay sensitivity to neurotoxic compounds. Application of paclitaxel at day 7 produced a larger assay window at neuronal maturity (day 21) compared with treatment initiated at day 14.
Taken together, these results illustrate the utility of NAMs as a physiologically relevant, scalable in vitro model for assessing drug response and toxicity.
