Generation of fluorescent zebrafish to study endocrine disruption and potential crosstalk between thyroid hormone and corticosteroids
- Authors
- Terrien, X., Fini, J.B., Demeneix, B.A., Schramm, K.W., and Prunet, P.
- ID
- ZDB-PUB-110629-8
- Date
- 2011
- Source
- Aquatic toxicology (Amsterdam, Netherlands) 105(1-2): 13-20 (Journal)
- Registered Authors
- Keywords
- zebrafish, bisphenol A, thyroid hormone, green fluorescent protein, corticosteroid
- MeSH Terms
-
- Adrenal Cortex Hormones/genetics
- Adrenal Cortex Hormones/metabolism*
- Animals
- Animals, Genetically Modified/metabolism
- Benzhydryl Compounds
- Embryo, Nonmammalian/drug effects
- Embryo, Nonmammalian/metabolism
- Endocrine Disruptors/toxicity*
- Endocrine System/drug effects*
- Endocrine System/metabolism
- Gene Expression/drug effects
- Green Fluorescent Proteins/metabolism
- Phenols/toxicity*
- Thyroid Hormones/genetics
- Thyroid Hormones/metabolism*
- Water Pollutants, Chemical/toxicity
- Zebrafish/metabolism
- PubMed
- 21684237 Full text @ Aquat. Toxicol.
- CTD
- 21684237
Several environmental chemicals disrupt thyroid function, a key regulator of normal development involved in many physiological processes in fish. We studied the effects of such chemicals in vivo using transient transgenic zebrafish (Danio rerio), expressing Green Fluorescent Protein (GFP) under the control of a TH/bZIP promoter from Xenopus laevis. Exposure to thyroid hormone (T3) at 10-8 M increased GFP fluorescence in F0 embryos and larvae. Transient transgenic embryos were exposed to a T3 signaling agonist (TRIAC) or antagonists (NH3 or NaClO4), or to the endocrine disruptor Bisphenol A (BPA). When tested alone, TRIAC increased fluorescence, confirming the specificity of our model. Exposure to NH3 or NaClO4 decreased fluorescence, reflecting inhibition of thyroid function. When tested alone, BPA did not modify fluorescence, but when tested with T3, it significantly reduced T3-induced fluorescence, suggesting disruption of the thyroid function by BPA. The expression of genes involved in the TH axis (TR-alpha, TR-beta, TSH) and the corticoid axis (GR and MR) was followed by q-PCR after T3 or BPA exposure (24 or 48 h) and at different developmental stages (0, 1, or 5 days post-fertilization). Expression of TR-alpha, TR-beta, and TSH genes increased after 48 h T3 exposure in 1-day-old larvae. When tested alone, BPA only slightly affected gene expression. When applied with T3, BPA decreased expression of all candidate genes in 1-day-old embryos compared to the T3 treated group, in agreement with data obtained with the TH/bZIP-eGFP zebrafish model. Finally, we show that T3 exposure leads to up-regulation of MR and GR genes. This study provides a new rapid diagnostic tool for characterizing the disrupting effects of toxicants on thyroid function and suggests possible crosstalk between the TR and Corticoid Signaling system.