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A Redox Sensitive Pathway in the Mouse ES Cell Assay Modeled From ToxCast HTS Data
Citation:
CHANDLER, K. J., E. S. HUNTER, S. C. JEFFAY, H. P. NICHOLS, N. KLEINSTREUER, N. SIPES, AND T. Knudson. A Redox Sensitive Pathway in the Mouse ES Cell Assay Modeled From ToxCast HTS Data. Presented at Society of Teratology Annual Meeting, San Diego, CA, June 25 - 29, 2011.
Impact/Purpose:
we used the mouse embryonic stem cell (mESC) adherent cell differentiation and cytotoxicity platform to evaluate the effects of 309 environmental chemicals on mESCs.
Description:
The broad chemical landscape coupled with the lack of developmental toxicity information across most environmental chemicals has motivated the need for high- throughput screening methods and predictive models of developmental toxicity. Towards this end, we used the mouse embryonic stem cell (mESC) adherent cell differentiation and cytotoxicity platform to evaluate the effects of 309 environmental chemicals on mESCs. In brief, J1 mESCs were exposed to chemicals at 0.0125-12.5 uM concentrations (or DMSO vehicle) in the absence of pluripotency factors. Differentiation and cytotoxicity were measured by In-Cell Western™ analysis of Myosin Heavy Chain (MHC), a cardiomyocyte marker, and DRAQ5™/Sapphire700™, respectively. Curve fitting methods were used to calculate half-maximal activities (AC50) and twenty percent (AC20) activities. This analysis indentified 71 of 309 chemicals with sufficient potency to produce an AC20 for MHC expression in the concentration range evaluated. Comparison to over 500 Toxcast™ assays produced a strong multivariate model (Balanced Accuracy=0.72) indicating a subset of environmental chemicals target a redox-sensitive pathway. Because redox signaling is tightly regulated during embryogenesis, we hypothesize that disruption of this signaling pathway may predict the potential for a chemical to perturb development. Subsequent ToxPi™ analysis has further allowed us to rank ToxCast chemicals by their redox disrupting activities and prioritize additional testing on putative redox disrupting chemicals (pRDCs). [This abstract does not necessarily reflect U.S. EPA policy.]