Coordinated waves of gene expression during neuronal differentiation of embryonic stem cells as basis for novel approaches to developmental neurotoxicity testing

Marcel Leist (1) , Bastian Zimmer (1) , Philipp Balthasar Kuegler (1) , Birte Baudis (1) , Andreas Genewsky (1) , Vivek Tanavde (1) , Winston Koh (1) , Betty Tan (1) , Tanja Waldmann (1) , Suzanne Kadereit (1)

1 Faculty of Biology

As neuronal differentiation of embryonic stem cells recapitulates embryonic neurogenesis, disturbances of this process may model developmental neurotoxicity (DNT). To identify the relevant steps of in vitro neurodevelopment, we implemented a differentiation protocol yielding neurons with desired electrophysiological properties. Results from focussed transcriptional profiling suggested that detection of non-cytotoxic developmental disturbances triggered by toxicants such as retinoic acid or cyclopamine was possible. Therefore, a broad transcriptional profile of the 20-day differentiation process was obtained. Cluster analysis of expression kinetics, and bioinformatic identification of overrepresented gene ontologies revealed waves of regulation relevant for DNT testing. We further explored the concept of superimposed waves as descriptor of ordered, but overlapping biological processes. The initial wave of transcripts indicated reorganisation of chromatin and epigenetic changes. Then, a transient upregulation of genes involved in the formation and patterning of neuronal precursors followed. Simultaneously, a long wave of ongoing neuronal differentiation started. This was again superseded towards the end of the process by shorter waves of neuronal maturation that yielded information on specification, extracellular matrix formation, disease-associated genes, and the generation of glia. Short exposure to lead during the final differentiation phase, disturbed neuronal maturation. Thus, the wave kinetics and the patterns of neuronal specification define the time windows and endpoints for examination of DNT.

Mots clés: stem cell; electrophysiology; neuron; developmental neurotoxicity; astrocyte

Marcel Leist, Bastian Zimmer, Philipp Balthasar Kuegler, Birte Baudis, Andreas Genewsky, et al.. Coordinated waves of gene expression during neuronal differentiation of embryonic stem cells as basis for novel approaches to developmental neurotoxicity testing. Cell Death and Differentiation, 2010, ⟨10.1038/cdd.2010.109⟩. ⟨hal-00579480⟩