Skip to main content
eScholarship
Open Access Publications from the University of California

Activation of steroid and xenobiotic receptor (SXR, NR1/2) and its orthologs in laboratory, toxicologic, and genome model species

  • Author(s): Milnes, MR
  • Garcia, A
  • Grossman, E
  • Grün, F
  • Shiotsugu, J
  • Tabb, MM
  • Kawashima, Y
  • Katsu, Y
  • Watanabe, H
  • Iguchi, T
  • Blumberg, B
  • et al.

Published Web Location

https://doi.org/10.1289/ehp.10853Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International Public License
Abstract

Background: Nuclear receptor subfamily 1, group I, member 2 (NR1I2), commonly known as steroid xenobiotic receptor (SXR) in humans, is a key ligand-dependent transcription factor responsible for the regulation of xenobiotic, steroid, and bile acid metabolism. The ligand-binding domain is principally responsible for species-specific activation of NR1I2 in response to xenobiotic exposure. Objectives: Our objective in this study was to create a common framework for screening NR1I2 orthologs from a variety of model species against environmentally relevant xenobiotics and to evaluate the results in light of using the species as predictors of xenobiotic disposition and for assessment of environmental health risk. Methods: Sixteen chimeric fusion plasmid vectors expressing the Gal4 DNA-binding domain and species-specific NR1I2 ligand-binding domain were screened for activation against a spectrum of 27 xenobiotic compounds using a standardized cotransfection receptor activation assay. Results: NR1I2 orthologs were activated by various ligands in a dose-dependent manner. Closely related species show broadly similar patterns of activation; however, considerable variation to individual compounds exists, even among species varying in only a few amino acid residues. Conclusions: Interspecies variation in NR1I2 activation by various ligands can be screened through the use of in vitro NR1I2 activation assays and should be taken into account when choosing appropriate animal models for assessing environmental health risk.

Many UC-authored scholarly publications are freely available on this site because of the UC Academic Senate's Open Access Policy. Let us know how this access is important for you.

Main Content
Current View