Evaluation of the effect of acetochlor on thyroid hormone receptor gene expression in the brain and behavior of Rana catesbeiana tadpoles

Helbing, Caren C.; Ovaska, Kristiina; Lan, Jing

doi:10.1016/j.aquatox.2006.07.011

Cited by 60 publications

(35 citation statements)

References 31 publications

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“…So far, the model organism Xenopus laevis is the most commonly used species to study TH signaling disruption (Crump et al, 2002;Fini et al, 2007;Searcy et al, 2012;Zhang et al, 2014). Also, certain native amphibian species are promising as test species for TH signaling disruption research (Hammond et al, 2013;Helbing et al, 2006;Veldhoen et al, 2014a). The black-spotted frog (Pelophylax nigromaculatus, formerly Rana nigromaculata) is a native frog species widespread in East Asia.…”

Section: Introductionmentioning

confidence: 99%

A screening assay for thyroid hormone signaling disruption based on thyroid hormone-response gene expression analysis in the frog Pelophylax nigromaculatus

Zhang

Qin

et al. 2015

Journal of Environmental Sciences

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Amphibian metamorphosis provides a wonderful model to study the thyroid hormone (TH) signaling disrupting activity of environmental chemicals, with Xenopus laevis as the most commonly used species. This study aimed to establish a rapid and sensitive screening assay based on TH-response gene expression analysis using Pelophylax nigromaculatus, a native frog species distributed widely in East Asia, especially in China. To achieve this, five candidate TH-response genes that were sensitive to T3 induction were chosen as molecular markers, and T3 induction was determined as 0.2 nmol/L T3 exposure for 48 hr. The developed assay can detect the agonistic activity of T3 with a lowest observed effective concentration of 0.001 nmol/L and EC50 at around 0.118-1.229 nmol/L, exhibiting comparable or higher sensitivity than previously reported assays. We further validated the efficiency of the developed assay by detecting the TH signaling disrupting activity of tetrabromobisphenol A (TBBPA), a known TH signaling disruptor. In accordance with previous reports, we found a weak TH agonistic activity for TBBPA in the absence of T3, whereas a TH antagonistic activity was found for TBBPA at higher concentrations in the presence of T3, showing that the P. nigromaculatus assay is effective for detecting TH signaling disrupting activity. Importantly, we observed non-monotonic dose-dependent disrupting activity of TBBPA in the presence of T3, which is difficult to detect with in vitro reporter gene assays. Overall, the developed P. nigromaculatus assay can be used to screen TH signaling disrupting activity of environmental chemicals with high sensitivity.

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Section: Introductionmentioning

confidence: 99%

A screening assay for thyroid hormone signaling disruption based on thyroid hormone-response gene expression analysis in the frog Pelophylax nigromaculatus

Zhang

Qin

et al. 2015

Journal of Environmental Sciences

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“…To validate R. nigromaculata as a native model species for assaying TH signaling disrupting effects in future study, in this study, we investigated the responsiveness of TR expression to an exogenous TR agonist (T3) and antagonist (AM) in R. nigromaculata tadpoles. In accordance with other amphibian species (Baker and Tata, 1992;Iwamuro et al, 2006;Jagnytsch et al, 2006;Helbing et al, 2006) TRβ expression is a better endpoint than TRα expression for assaying TH signaling disrupting actions. In addition, it was found that the responsiveness of TR expression to TH decreased with R. nigromaculata development.…”

Section: Responsiveness Of Tr Expression To Exogenous Tr Agonist and mentioning

confidence: 92%

“…The Amphibian Metamorphosis Assay developed by OECD (2009) has been applied to screen thyroid disruptors that may interfere with the normal functioning of the HPT axis (Carr and Patino, 2011;Gutleb et al, 2007). In addition, TH-induced metamorphosis is also used to identify thyroid disruptors that may bind to TRs and alter TH actions and signaling (Heimeier et al, 2009;Helbing et al, 2006). TH-dependent gene expression and morphological changes induced by TH are regarded as good endpoints for evaluating TH signaling disrupting effects of chemicals (Heimeier et al, 2009;Helbing et al, 2006;Fini et al, 2012).…”

Section: Introductionmentioning

confidence: 99%

“…Given the obtainability of experimental animals, some native amphibian species, such as Rana catesbeiana and Rana pipiens (Helbing et al, 2006;Croteau et al, 2009), Rana temporaria (Arukwe and Jenssen, 2005;Gutleb et al, 2000) and Rana rugosa (Hanada et al, 2003;Oka et al, 2009), are used to assess effects of chemicals on the thyroid system. Rana nigromaculata (Pelophylax nigromaculatus) is a species of true frog distributed in East Asia.…”

Section: Introductionmentioning

confidence: 99%

“…In addition, TH-induced metamorphosis is also used to identify thyroid disruptors that may bind to TRs and alter TH actions and signaling (Heimeier et al, 2009;Helbing et al, 2006). TH-dependent gene expression and morphological changes induced by TH are regarded as good endpoints for evaluating TH signaling disrupting effects of chemicals (Heimeier et al, 2009;Helbing et al, 2006;Fini et al, 2012). In particular, TH-induced expression of TRs (especially TRβ) has been used as a molecular biomarker for evaluating TH signaling disrupting effects in amphibians Veldhoen et al, 2006a, b).…”

Section: Introductionmentioning

confidence: 99%

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Molecular characterization and developmental expression patterns of thyroid hormone receptors (TRs) and their responsiveness to TR agonist and antagonist in Rana nigromaculata

Lou

Zhang

Ren

et al. 2014

Journal of Environmental Sciences

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Considering some advantages of Rana nigromaculata as an experimental species, we propose that this species, like Xenopus laevis, could be used to assay thyroid hormone (TH) signaling disrupting actions. To validate the utilizability of R. nigromaculata, we investigated the responsiveness of R. nigromaculata to a TH receptor (TR) agonist (T3) and antagonist (amiodarone) by analyzing expression, based on characterizing TR cDNA and developmental expression patterns. With high levels of identity with the corresponding genes in X. laevis, both TRα and TRβ in R. nigromaculata exhibited roughly similar developmental expression patterns to those of X. laevis, in spite of some species-specific differences. Both TRα and TRβ expression had greater changes in the liver and intestine than in the tail and brain during metamorphosis. T3 exposure for 2 days induced more dramatic increases of TRβ expression in stage 27 than in stage 34 tadpoles but not in stage 42 tadpoles, showing that the responsiveness of R. nigromaculata to TH decreased with development and disappeared at the onset of metamorphic climax.Corresponding to greater changes of TRβ expression in the liver and intestine than in the tail and brain during metamorphosis, the liver and intestine had higher responsiveness to exogenous T3 than the tail and brain. Amiodarone inhibited T3-induced TRβ expression. Our results show that R. nigromaculata can be used as a model species for assaying TH signaling disrupting actions by analyzing TRβ expression, and intestine tissues at stage 27 are ideal test materials due to high responsiveness and easy accessibility.

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Comparative Acute and Chronic Sensitivity of Fish and Amphibians: A Critical Review of Data

Weltje¹,

Simpson

Gross

et al. 2013

Enviro Toxic and Chemistry

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Abstract-The relative sensitivity of amphibians to chemicals in the environment, including plant protection product active substances, is the subject of ongoing scientific debate. The objective of this study was to compare systematically the relative sensitivity of amphibians and fish to chemicals. Acute and chronic toxicity data were obtained from the U.S. Environmental Protection Agency (U.S. EPA) ECOTOX database and were supplemented with data from the scientific and regulatory literature. The overall outcome is that fish and amphibian toxicity data are highly correlated and that fish are more sensitive (both acute and chronic) than amphibians. In terms of acute sensitivity, amphibians were between 10-and 100-fold more sensitive than fish for only four of 55 chemicals and more than 100-fold more sensitive for only two chemicals. However, a detailed inspection of these cases showed a similar acute sensitivity of fish and amphibians. Chronic toxicity data for fish were available for 52 chemicals. Amphibians were between 10-and 100-fold more sensitive than fish for only two substances (carbaryl and dexamethasone) and greater than 100-fold more sensitive for only a single chemical (sodium perchlorate). The comparison for carbaryl was subsequently determined to be unreliable and that for sodium perchlorate is a potential artifact of the exposure medium. Only a substance such as dexamethasone, which interferes with a specific aspect of amphibian metamorphosis, might not be detected using fish tests. However, several other compounds known to influence amphibian metamorphosis were included in the analysis, and these did not affect amphibians disproportionately. These analyses suggest that additional amphibian testing is not necessary during chemical risk assessment. Environ. Toxicol. Chem. 2013;32:984-994.

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Evaluation of the effect of acetochlor on thyroid hormone receptor gene expression in the brain and behavior of Rana catesbeiana tadpoles

Cited by 60 publications

References 31 publications

A screening assay for thyroid hormone signaling disruption based on thyroid hormone-response gene expression analysis in the frog Pelophylax nigromaculatus

A screening assay for thyroid hormone signaling disruption based on thyroid hormone-response gene expression analysis in the frog Pelophylax nigromaculatus

Molecular characterization and developmental expression patterns of thyroid hormone receptors (TRs) and their responsiveness to TR agonist and antagonist in Rana nigromaculata

Comparative Acute and Chronic Sensitivity of Fish and Amphibians: A Critical Review of Data

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