Data from Tiered High-Throughput Screening Approach to Identify Thyroperoxidase Inhibitors within the ToxCast Phase I and II Chemical Libraries

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).

                                            [
  "020:00"
]
                                        

                                            {
  "fn": "Steven Simmons",
  "hasEmail": "mailto:simmons.steve@epa.gov"
}
                                        

                                            [
  {
    "title": "https://gaftp.epa.gov/COMPTOX/NCCT_Publication_Data/FriedmanPaul_K/2016_TPO_ToxCast_ToxSci",
    "accessURL": "https://gaftp.epa.gov/COMPTOX/NCCT_Publication_Data/FriedmanPaul_K/2016_TPO_ToxCast_ToxSci"
  },
  {
    "title": "Figures and Tables_v10.docx",
    "mediaType": "application/vnd.openxmlformats-officedocument.wordprocessingml.document",
    "downloadURL": "https://pasteur.epa.gov/uploads/97/Figures%20and%20Tables_v10.docx"
  }
]
                                        

                                            [
  "Thyroperoxidase",
  "ToxCast",
  "chemical safety for sustainablity",
  "chemical safety research",
  "endocrine disruption",
  "high-throughput toxicology"
]
                                        

                                            [
  "020:095"
]
                                        

                                            {
  "name": "U.S. EPA Office of Research and Development (ORD)",
  "subOrganizationOf": {
    "name": "U.S. Environmental Protection Agency",
    "subOrganizationOf": {
      "name": "U.S. Government"
    }
  }
}
                                        

                                            [
  "https://doi.org/10.1093/toxsci/kfw034"
]
                                        

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