Neurotoxicity remains a major safety concern for pharmaceuticals and environmental chemicals, and fully in vitro methods are not yet recognised by governing bodies such as the OECD. However, 3D microtissues cultured from iPSC neurons and astrocytes and, analysed using High Content Screening (HCS) provide an alternative to animal models or ex vivo models such as the brain slice assay.
Like other 3D microtissue models, brain 3D microtissues display uniform size, shape and longevity, thus making them a viable candidate for long-term dosing and chronic exposure studies. The microtissues also exhibit key cell markers, such as ßIII-tubulin as markers for neurons and glial fibrillary acidic protein (GFAP) as markers for astrocytes.
Following exposure to eight known neurotoxins and two non-neurotoxins, the cells were labelled with fluorescent dyes to monitor nuclear morphology, DNA structure, calcium homeostasis and mitochondrial function using confocal HCS. Using this approach following a 14 day exposure, 60% of neurotoxins were correctly identified when data was normalised to plasma Cmax. However, when normalised to brain tissue-specific Cmax (tsCmax), this figure improved to 80%. These results illustrate the value of combining 3D brain microtissue data generated using confocal HCS with predicted tissue levels to detect organ-specific toxicity.
This research was presented at Eurotox 2016. Download the poster.