Developmental Toxicity Assay Based on Real-Time Monitoring of Fibroblast Growth Factor Signal Disruption in Human Induced Pluripotent Stem Cells.

Developmental toxicity (Devtox) is typically evaluated in animal models. However, there are challenges in ensuring accuracy, such as false negatives due to interspecies differences and ethical concerns regarding animal welfare. Therefore, there is a need for new test systems to evaluate human Devtox and help address these issues. We hypothesized that teratogens disrupt Devtox-related signaling pathways essential for morphogenesis, irrespective of their molecular targets. To test this hypothesis, we developed a fibroblast growth factor (FGF) reporter system using human induced pluripotent stem (iPS) cells. This system enables quantification of signal disruption caused by chemicals, achieving an accuracy rate of 83% for known teratogenic and non-teratogenic compounds. Because Devtox signaling activity changes over time, it is important to capture its dynamics continuously rather than measuring at a single endpoint. Use of a real-time luminescence measurement system is optional, but it enhances temporal resolution with less labor. The entire test can be completed within 1 week, from seeding cells in a culture plate to acquiring luminescence data.