PUBLICATION

Effects of 25 thyroid hormone disruptors on zebrafish embryos: A literature review of potential biomarkers

Authors
Spaan, K., Haigis, A.C., Weiss, J., Legradi, J.
ID
ZDB-PUB-190113-1
Date
2019
Source
The Science of the total environment   656: 1238-1249 (Review)
Registered Authors
Legradi, Jessica
Keywords
Biomarker, EDC, HPT axis, Thyroid endocrine disruption, Zebrafish embryo/larvae
MeSH Terms
  • Animals
  • Biomarkers/metabolism*
  • Embryo, Nonmammalian/drug effects*
  • Embryonic Development/drug effects*
  • Endocrine Disruptors/adverse effects*
  • Thyroid Hormones/metabolism*
  • Zebrafish/embryology
  • Zebrafish/growth & development
PubMed
30625654 Full text @ Sci. Total Environ.
Abstract
It is estimated that many organic compounds found in our environment can interfere with the thyroid system and act as thyroid hormone (TH) disruptor. Despite that, there is a clear lack of assays to identify TH disruptors. Recently zebrafish embryos were suggested as screening tool to identify compounds which impact thyroid synthesis. Effects on hormone level, gene transcript expression, eye development and swim bladder inflation are suggested as potential biomarker for TH disruptors. In order to assess the applicability of these biomarkers we performed a literature review. The effects of 25 known TH disrupting compounds were compared between studies. The studies were limited to exposures with embryos prior 7 days of development. The different study designs and the lack of standardized methods complicated the comparison of the results. The most common responses were morphological alterations and gene transcript expression changes, but no specific biomarker for TH disruption could be identified. In studies addressing TH disruption behavioral effects were more commonly monitored than in studies not mentioning the TH pathway. TH disruption in developing zebrafish embryos might be caused by different modes of action e.g. disruption of follicle development, binding of TH, activation of TH receptors causing different effects. Timing of developmental processes in combination with exposure duration might also play a role. On the other side compound characteristics (uptake, stability, metabolization) could also cause differences between substances. Further studies are necessary to gain better understanding into the mechanisms of TH disruption in early zebrafish development.
Genes / Markers
Figures
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping