Dioxin exerts anti-estrogenic actions in a novel dioxin-responsive telomerase-immortalized epithelial cell line of the porcine oviduct (TERT-OPEC)

Toxicol Sci. 2006 Apr;90(2):519-28. doi: 10.1093/toxsci/kfj102. Epub 2006 Jan 23.

Abstract

Oviduct epithelial cells are important for the nourishment and survival of ovulated oocytes and early embryos, and they respond to the steroid hormones estrogen and progesterone. Endocrine-disrupting polyhalogenated aromatic hydrocarbons (PHAH) are environmental toxins that act in part through the ligand-activated transcription factor arylhydrocarbon receptor (AhR; dioxin receptor), and exposure to PHAH has been shown to decrease fertility. To investigate effects of PHAHs on the oviduct epithelium as a potential target tissue of dioxin-type endocrine disruptors, we have established a novel telomerase-immortalized oviduct porcine epithelial cell line (TERT-OPEC). TERT-OPEC exhibited active telomerase and the immunoreactive epithelial marker cytokeratin but lacked the stromal marker vimentin. TERT-OPEC contained functional estrogen receptor (ER)-alpha and AhR, as determined by the detection of ER-alpha- and AhR-specific target molecules. Treatment of TERT-OPEC with the AhR ligand 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) resulted in a significant increase in the production of the cytochrome P-450 microsomal enzyme CYP1A1. Activated AhR caused a downregulation of ER nuclear protein fraction and significantly decreased ER-signaling in TERT-OPEC as determined by ERE-luciferase transient transfection assays. In summary, the TCDD-induced and AhR-mediated anti-estrogenic responses by TERT-OPEC suggest that PHAH affect the predominantly estrogen-dependent differentiation of the oviduct epithelium within the fallopian tube. This action then alters the local endocrine milieu, potentially resulting in a largely unexplored cause of impaired embryonic development and female infertility.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Line*
  • Cytochrome P-450 CYP1A1 / genetics
  • Cytochrome P-450 CYP1A1 / metabolism
  • Environmental Pollutants / toxicity
  • Epithelial Cells / drug effects
  • Epithelial Cells / metabolism
  • Estrogen Receptor Modulators / toxicity
  • Estrogen Receptor alpha / genetics
  • Estrogen Receptor alpha / metabolism
  • Female
  • Gene Expression Regulation / drug effects
  • Genes, Reporter / genetics
  • Luciferases / metabolism
  • Oviducts / cytology*
  • Oviducts / drug effects*
  • Oviducts / metabolism
  • Polychlorinated Dibenzodioxins / toxicity*
  • RNA, Messenger / metabolism
  • Receptors, Aryl Hydrocarbon / metabolism
  • Response Elements / genetics
  • Swine*
  • Telomerase / metabolism
  • Transfection

Substances

  • Environmental Pollutants
  • Estrogen Receptor Modulators
  • Estrogen Receptor alpha
  • Polychlorinated Dibenzodioxins
  • RNA, Messenger
  • Receptors, Aryl Hydrocarbon
  • Luciferases
  • Cytochrome P-450 CYP1A1
  • Telomerase