Data from Tiered High-Throughput Screening Approach to Identify Thyroperoxidase Inhibitors within the ToxCast Phase I and II Chemical Libraries
2017
high throughput screening for potential thyroid disrupting chemicals requires a system of assays to capture multiple molecular initiating events mies that converge on perturbed thyroid hormone th homeostasis screening for mies specific to th disrupting pathways is limited in the u s environmental protection agency toxcast screening assay portfolio to fill 1 critical screening gap the amplex ultrared thyroperoxidase aur tpo assay was developed to identify chemicals that inhibit tpo as decreased tpo activity reduces th synthesis the toxcast phase i and ii chemical libraries comprised of 1074 unique chemicals were initially screened using a single high concentration to identify potential tpo inhibitors chemicals positive in the single concentration screen were retested in concentration response due to high false positive rates typically observed with loss of signal assays such as aur tpo we also employed 2 additional assays in parallel to identify possible sources of nonspecific assay signal loss enabling stratification of roughly 300 putative tpo inhibitors based upon selective aur tpo activity a cell free luciferase inhibition assay was used to identify nonspecific enzyme inhibition among the putative tpo inhibitors and a cytotoxicity assay using a human cell line was used to estimate the cellular tolerance limit additionally the tpo inhibition activities of 150 chemicals were compared between the aur tpo and an orthogonal peroxidase oxidation assay using guaiacol as a substrate to confirm the activity profiles of putative tpo inhibitors this effort represents the most extensive tpo inhibition screening campaign to date and illustrates a tiered screening approach that focuses resources maximizes assay throughput and reduces animal use this dataset is associated with the following publication paul friedman k e d watt m w hornung j m hedge r s judson k m crofton k a houck and s o simmons toxicological sciences tiered high throughput screening approach to identify thyroperoxidase inhibitors within the toxcast phase i and ii chemical libraries toxicological sciences society of toxicology 1 59 2016