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Linking DNT In Vitro Battery Endpoints to Adverse Outcome Pathways using Omics Approaches
Citation:
Shafer, T. Linking DNT In Vitro Battery Endpoints to Adverse Outcome Pathways using Omics Approaches. 5th International Conference on Developmental Neurotoxicity Testing (DNT5), Konstanz, GERMANY, April 07 - 10, 2024. https://doi.org/10.23645/epacomptox.25605633
Impact/Purpose:
Presentation to the 5th International Conference on Developmental Neurotoxicity Testing (DNT5) April 2024
Description:
Development of in vitro new approach methodologies (NAMs) has been driven by the need for developmental neurotoxicity (DNT) hazard data on thousands of chemicals. The network formation assay (NFA) characterizes DNT hazard based on changes in network formation but provides no mechanistic information. Previously, we demonstrated that combined transcriptomic and metabolomic analysis could be used to identify nervous system signaling pathways and upstream physiological regulators underlying chemically-induced neural network dysfunction using a small set of proof-of-concept chemicals. Such information can be informative for putative AOP development. Here, we expand this approach by evaluating 18 additional chemicals that fall into four broad categories; metals/organometals, gaba modulators, organophosphates and fungicides. Rat primary cortical neural networks grown on microelectrode arrays were exposed to one of the test compounds for 12 days in vitro (DIV) Based on previous evaluations in MEAs, three concentrations near the tipping point for disruption of network formation of each compound, were used for exposures. RNA-seq from cells and GC/MS analysis of media extracts collected on DIV 12 provided gene expression and metabolomic identification, respectively. The integration of differentially expressed genes and metabolites for each neurotoxicant was analyzed using Ingenuity Pathway Analysis. In the combined transcriptomic/metabolomic analysis, all compounds altered processes linked to developmental disorders and neurological diseases. Some enriched canonical pathways overlapped among compounds of the same class; for example, genes and metabolites influenced by metals often included perturbations to ion transport and neurotransmitter/energetic metabolic mechanisms. Upstream regulators identified by the combined analysis were more heterogeneous across all compounds, but identified several transcriptomic regulators including SOX2, BDNF, and MAPT existing in the causal network of many compound disruptions. These results further demonstrate that changes in network formation are accompanied by transcriptomic and metabolomic changes and that different classes of compounds produce differing responses. Information from this “omic” approach can be combined with data from DNT NAMs and other data from in vitro and in vivo studies to facilitate the identification and development of adverse outcome pathways (AOPs) associated with DNT, thus enhancing the information obtained from NAMs. (This abstract does not reflect US EPA policy)
URLs/Downloads:
DOI: Linking DNT In Vitro Battery Endpoints to Adverse Outcome Pathways using Omics Approaches
SHAFER_DNT5_TUESDAY_FINAL_240415.PDF (PDF, NA pp, 1578.062 KB, about PDF)