PUBLICATION

Developmental exposure to triclosan and benzophenone-2 causes morphological alterations in zebrafish (Danio rerio) thyroid follicles and eyes

Authors
Kraft, M., Gölz, L., Rinderknecht, M., Koegst, J., Braunbeck, T., Baumann, L.
ID
ZDB-PUB-221211-2
Date
2022
Source
Environmental science and pollution research international   30(12): 33711-33724 (Journal)
Registered Authors
Braunbeck, Thomas
Keywords
Disinfectant, Endocrine disruptor, Histopathology, OECD guidelines, Transgenic line, UV filter
MeSH Terms
  • Animals
  • Benzophenones/toxicity
  • Thyroid Gland
  • Thyroid Hormones/metabolism
  • Triclosan*/metabolism
  • Triclosan*/toxicity
  • Water Pollutants, Chemical*/metabolism
  • Zebrafish/genetics
PubMed
36495432 Full text @ Environ. Sci. Pollut. Res. Int.
Abstract
Thyroid hormones (THs) regulate a multitude of developmental and metabolic processes, which are responsible for vertebrate development, growth, and maintenance of homeostasis. THs also play a key role in neurogenesis of vertebrates and thus affect eye development, which is vital for foraging efficiency and for effective escape from predation. Currently, there are no validated test guidelines for the assessment of TH system-disrupting chemicals (THSDCs) in fish. Consequently, the present study was designed to demonstrate the suitability of novel thyroid-related endpoints in early life-stages of fish. Embryos of a transgenic zebrafish (Danio rerio) line expressing the reporter gene tg:mCherry in their thyrocytes were used to investigate the effects of the environmental THSDCs triclosan (TCS, antibacterial agent) and benzophenone-2 (BP-2, UV filter) on thyroid follicle and eye development. Both BP-2 and TCS caused thyroid follicle hyperplasia in transgenic zebrafish, thus confirming their role as THSDCs. The effect intensity on follicle size and fluorescence was comparable with a 1.7-fold increase for BP-2 and 1.6-fold for TCS. Alterations of the cellular structures of the retina indicate an impact of both substances on eye development, with a stronger impact of TCS. With respect to guideline development, results provide further evidence for the suitability of morphological changes in thyroid follicles and the eyes as novel endpoints for the sensitive assessment of THSD-related effects in fish.
Genes / Markers
Figures
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Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping