Whole genome microarray analysis of neural progenitor C17.2 cells during differentiation and validation of 30 neural mRNA biomarkers for estimation of developmental neurotoxicity

PLoS One. 2017 Dec 20;12(12):e0190066. doi: 10.1371/journal.pone.0190066. eCollection 2017.

Abstract

Despite its high relevance, developmental neurotoxicity (DNT) is one of the least studied forms of toxicity. Current guidelines for DNT testing are based on in vivo testing and they require extensive resources. Transcriptomic approaches using relevant in vitro models have been suggested as a useful tool for identifying possible DNT-generating compounds. In this study, we performed whole genome microarray analysis on the murine progenitor cell line C17.2 following 5 and 10 days of differentiation. We identified 30 genes that are strongly associated with neural differentiation. The C17.2 cell line can be differentiated into a co-culture of both neurons and neuroglial cells, giving a more relevant picture of the brain than using neuronal cells alone. Among the most highly upregulated genes were genes involved in neurogenesis (CHRDL1), axonal guidance (BMP4), neuronal connectivity (PLXDC2), axonogenesis (RTN4R) and astrocyte differentiation (S100B). The 30 biomarkers were further validated by exposure to non-cytotoxic concentrations of two DNT-inducing compounds (valproic acid and methylmercury) and one neurotoxic chemical possessing a possible DNT activity (acrylamide). Twenty-eight of the 30 biomarkers were altered by at least one of the neurotoxic substances, proving the importance of these biomarkers during differentiation. These results suggest that gene expression profiling using a predefined set of biomarkers could be used as a sensitive tool for initial DNT screening of chemicals. Using a predefined set of mRNA biomarkers, instead of the whole genome, makes this model affordable and high-throughput. The use of such models could help speed up the initial screening of substances, possibly indicating alerts that need to be further studied in more sophisticated models.

MeSH terms

  • Acrylamide / toxicity
  • Animals
  • Biomarkers / metabolism*
  • Cell Differentiation / drug effects
  • Cell Differentiation / genetics*
  • Cell Line
  • Cell Survival / drug effects
  • Cell Survival / genetics
  • Gene Expression Profiling
  • Gene Expression Regulation / drug effects
  • Genome*
  • Mannitol / toxicity
  • Methylmercury Compounds / toxicity
  • Mice
  • Microarray Analysis / methods*
  • Neural Stem Cells / cytology*
  • Neural Stem Cells / drug effects
  • Neural Stem Cells / metabolism*
  • Neurotoxicity Syndromes / genetics*
  • Principal Component Analysis
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Reproducibility of Results
  • Time Factors
  • Valproic Acid / toxicity

Substances

  • Biomarkers
  • Methylmercury Compounds
  • RNA, Messenger
  • Acrylamide
  • Mannitol
  • Valproic Acid

Grants and funding

The research at Stockholm University (KA, JL, AF) was funded by the Swedish research council (K2013-79X-21373-05-3). The research at Swetox (UN, AF) was supported by Stockholm County Council, Knut & Alice Wallenberg Foundation, and Swedish Research Council FORMAS and the Swedish Fund for Research without Animal Experiments. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.