1
|
Gölz L, Pannetier P, Fagundes T, Knörr S, Behnstedt L, Coordes S, Matthiessen P, Morthorst J, Vergauwen L, Knapen D, Holbech H, Braunbeck T, Baumann L. Development of the integrated fish endocrine disruptor test-Part B: Implementation of thyroid-related endpoints. Integr Environ Assess Manag 2024; 20:830-845. [PMID: 37578010 DOI: 10.1002/ieam.4828] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 06/21/2023] [Accepted: 08/10/2023] [Indexed: 08/15/2023]
Abstract
Given the vital role of thyroid hormones (THs) in vertebrate development, it is essential to identify chemicals that interfere with the TH system. Whereas, among nonmammalian laboratory animals, fish are the most frequently utilized test species in endocrine disruptor research, for example, in guidelines for the detection of effects on the sex hormone system, there is no test guideline (TG) using fish as models for thyroid-related effects; rather, amphibians are used. Therefore, the objective of the present project was to integrate thyroid-related endpoints for fish into a test protocol combining OECD TGs 229 (Fish Short-Term Reproduction Assay) and 234 (Fish Sexual Development Test). The resulting integrated Fish Endocrine Disruption Test (iFEDT) was designed as a comprehensive approach to covering sexual differentiation, early development, and reproduction and to identifying disruption not only of the sexual and/or reproductive system but also the TH system. Two 85-day exposure tests were performed using different well-studied endocrine disruptors: 6-propyl-2-thiouracil (PTU) and 17α-ethinylestradiol (EE2). Whereas the companion Part A of this study presents the findings on effects by PTU and EE2 on endpoints established in existing TGs, the present Part B discusses effects on novel thyroid-related endpoints such as TH levels, thyroid follicle histopathology, and eye development. 6-Propyl-2-thiouracil induced a massive proliferation of thyroid follicles in any life stage, and histopathological changes in the eyes proved to be highly sensitive for TH system disruption especially in younger life stages. For measurement of THs, further methodological development is required. 17-α-Ethinylestradiol demonstrated not only the well-known disruption of the hypothalamic-pituitary-gonadal axis, but also induced effects on thyroid follicles in adult zebrafish (Danio rerio) exposed to higher EE2 concentrations, suggesting crosstalk between endocrine axes. The novel iFEDT has thus proven capable of simultaneously capturing endocrine disruption of both the steroid and thyroid endocrine systems. Integr Environ Assess Manag 2024;20:830-845. © 2023 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).
Collapse
Affiliation(s)
- Lisa Gölz
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Heidelberg, Germany
| | - Pauline Pannetier
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Heidelberg, Germany
- Laboratoire de Ploufragan-Plouzané-Niort, Site de Plouzané, Agence nationale de sécurité sanitaire de l'alimentation, de l'environnement et du travail, Plouzané, France
| | - Teresa Fagundes
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Heidelberg, Germany
| | - Susanne Knörr
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Heidelberg, Germany
| | - Laura Behnstedt
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Heidelberg, Germany
| | - Sara Coordes
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Heidelberg, Germany
| | | | - Jane Morthorst
- Department of Biology, University of Southern Denmark, Odense, Denmark
| | - Lucia Vergauwen
- Department of Veterinary Sciences, Veterinary Physiology and Biochemistry, Zebrafishlab, University of Antwerp, Wilrijk, Belgium
| | - Dries Knapen
- Department of Veterinary Sciences, Veterinary Physiology and Biochemistry, Zebrafishlab, University of Antwerp, Wilrijk, Belgium
| | - Henrik Holbech
- Department of Biology, University of Southern Denmark, Odense, Denmark
| | - Thomas Braunbeck
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Heidelberg, Germany
| | - Lisa Baumann
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Heidelberg, Germany
- Amsterdam Institute for Life and Environment (A-LIFE), Section Environmental Health & Toxicology, Vrije Universiteit Amsterdam, HV Amsterdam, The Netherlands
| |
Collapse
|
2
|
Pannetier P, Gölz L, Pissarreira Mendes Fagundes MT, Knörr S, Behnstedt L, Coordes S, Matthiessen P, Morthorst JE, Vergauwen L, Knapen D, Holbech H, Braunbeck T, Baumann L. Development of the integrated fish endocrine disruptor test (iFEDT)-Part A: Merging of existing fish test guidelines. Integr Environ Assess Manag 2024; 20:817-829. [PMID: 37483114 DOI: 10.1002/ieam.4819] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 06/21/2023] [Accepted: 07/20/2023] [Indexed: 07/25/2023]
Abstract
There has been increasing interest in endocrine-disrupting chemicals (EDCs) among scientists and public authorities over the last 30 years, notably because of their wide use and the increasing evidence of detrimental effects on humans and the environment. However, test systems for the detection of potential EDCs as well as testing strategies still require optimization. Thus, the aim of the present project was the development of an integrated test protocol that merges the existing OECD test guidelines (TGs) 229 (fish short-term reproduction assay) and 234 (fish sexual development test) and implements thyroid-related endpoints for fish. The integrated fish endocrine disruptor test (iFEDT) represents a comprehensive approach for fish testing, which covers reproduction, early development, and sexual differentiation, and will thus allow the identification of multiple endocrine-disruptive effects in fish. Using zebrafish (Danio rerio) as a model organism, two exposure tests were performed with well-studied EDCs: 6-propyl-2-thiouracil (PTU), an inhibitor of thyroid hormone synthesis, and 17α-ethinylestradiol (EE2), an estrogen receptor agonist. In part A of this article, the effects of PTU and EE2 on established endpoints of the two existing TGs are reported, whereas part B focuses on the novel thyroid-related endpoints. Results of part A document that, as expected, both PTU and EE2 had strong effects on various endocrine-related endpoints in zebrafish and their offspring. Merging of TGs 229 and 234 proved feasible, and all established biomarkers and endpoints were responsive as expected, including reproductive and morphometric changes (PTU and EE2), vitellogenin levels, sex ratio, gonad maturation, and histopathology (only for EE2) of different life stages. A validation of the iFEDT with other well-known EDCs will allow verification of the sensitivity and usability and confirm its capacity to improve the existing testing strategy for EDCs in fish. Integr Environ Assess Manag 2024;20:817-829. © 2023 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).
Collapse
Affiliation(s)
- Pauline Pannetier
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Heidelberg, Germany
- Laboratoire de Ploufragan-Plouzané-Niort, Site de Plouzané, Agence nationale de sécurité sanitaire de l'alimentation, de l'environnement et du travail, Plouzané, France
| | - Lisa Gölz
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Heidelberg, Germany
| | | | - Susanne Knörr
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Heidelberg, Germany
| | - Laura Behnstedt
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Heidelberg, Germany
| | - Sara Coordes
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Heidelberg, Germany
| | | | - Jane E Morthorst
- Department of Biology, University of Southern Denmark, Odense, Denmark
| | - Lucia Vergauwen
- Department of Veterinary Sciences, Veterinary Physiology and Biochemistry, Zebrafishlab, University of Antwerp, Wilrijk, Belgium
| | - Dries Knapen
- Department of Veterinary Sciences, Veterinary Physiology and Biochemistry, Zebrafishlab, University of Antwerp, Wilrijk, Belgium
| | - Henrik Holbech
- Department of Biology, University of Southern Denmark, Odense, Denmark
| | - Thomas Braunbeck
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Heidelberg, Germany
| | - Lisa Baumann
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Heidelberg, Germany
- Amsterdam Institute for Life and Environment (A-LIFE), Section Environmental Health and Toxicology, Vrije Universiteit Amsterdam, HV Amsterdam, The Netherlands
| |
Collapse
|
3
|
Kämmer N, Reimann T, Braunbeck T. Neurotoxic pesticides change respiratory parameters in early gill-breathing, but not in skin-breathing life-stages of zebrafish (Danio rerio). Aquat Toxicol 2024; 267:106831. [PMID: 38244448 DOI: 10.1016/j.aquatox.2024.106831] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Revised: 12/31/2023] [Accepted: 01/07/2024] [Indexed: 01/22/2024]
Abstract
Neurotoxic compounds can interfere with active gill ventilation in fish, which might lead to premature death in adult fish, but not in skin-breathing embryos of zebrafish, since these exclusively rely on passive diffusion across the skin. Regarding lethality, this respiratory failure syndrome (RFS) has been discussed as one of the main reasons for the higher sensitivity of adult fish in the acute fish toxicity test (AFT), if compared to embryos in the fish embryo toxicity test (FET). To further elucidate the relationship between the onset of gill respiration and death by a neurotoxic mode of action, a comparative study into oxygen consumption (MO2), breathing frequency (fv) and amplitude (fampl) was performed with 4 d old skin-breathing and 12 d old early gill-breathing zebrafish. Neurotoxic model substances with an LC50 FET/AFT ratio of > 10 were used: chlorpyrifos, permethrin, aldicarb, ziram, and fluoxetine. Exposure to hypoxia served as a positive control, whereas aniline was tested as an example of a narcotic substance interfering non-specifically with gill membranes. In 12 d old larvae, all substances caused an increase in MO2, fv and partly fampl, whereas effects were minor in 4 d old embryos. An increase of fv in 4 d old embryos following exposure to chlorpyrifos, aldicarb and hypoxia could not be correlated with an increased MO2 and might be attributed either to (1) to the successfully postponed decrease of arterial partial pressure of oxygen (PO2) through support of skin respiration by increased fv, (2) to an unspecific stimulation of the sphincter muscles at the base of the gill filaments, or (3) to the establishment of oxygen sensing for later stages. In gill-breathing 12 d old zebrafish, a concentration-dependent increase of fv was detected for aniline and chlorpyrifos, whereas for aldicarb, fluoxetine and permethrin, a decline of fv at higher substance concentrations was measured, most likely due to the onset of paralysis and/or fatigue of the gill filament sphincter muscles. Since alterations of fv serve to postpone the decrease in arterial PO2 and MO2 increased with decreasing fv, the respiratory failure syndrome could clearly be demonstrated in 12 d old zebrafish larvae. Passive respiration across the skin in zebrafish embryos could thus be confirmed as a probable reason for the lower sensitivity of early life-stages to neurotoxicants. Integration of respiratory markers into existing testing protocols with non-protected developmental stages such as embryos might help to not underestimate the toxicity of early life-stages of fish.
Collapse
Affiliation(s)
- Nadine Kämmer
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, D-69210, Heidelberg, Germany.
| | - Tanja Reimann
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, D-69210, Heidelberg, Germany
| | - Thomas Braunbeck
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, D-69210, Heidelberg, Germany.
| |
Collapse
|
4
|
Pannetier P, Poulsen R, Gölz L, Coordes S, Stegeman H, Koegst J, Reger L, Braunbeck T, Hansen M, Baumann L. Reversibility of Thyroid Hormone System-Disrupting Effects on Eye and Thyroid Follicle Development in Zebrafish (Danio rerio) Embryos. Environ Toxicol Chem 2023; 42:1276-1292. [PMID: 36920003 DOI: 10.1002/etc.5608] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 09/13/2022] [Accepted: 03/10/2023] [Indexed: 05/27/2023]
Abstract
Early vertebrate development is partially regulated by thyroid hormones (THs). Environmental pollutants that interact with the TH system (TH system-disrupting chemicals [THSDCs]) can have massively disrupting effects on this essential phase. Eye development of fish is directly regulated by THs and can, therefore, be used as a thyroid-related endpoint in endocrine disruptor testing. To evaluate the effects of THSDC-induced eye malformations during early development, zebrafish (Danio rerio) embryos were exposed for 5 days postfertilization (dpf) to either propylthiouracil, a TH synthesis inhibitor, or tetrabromobisphenol A, which interacts with TH receptors. Subsequently, one half of the embryos were exposed further to the THSDCs until 8 dpf, while the other half of the embryos were raised in clean water for 3 days to check for reversibility of effects. Continued THSDC exposure altered eye size and pigmentation and induced changes in the cellular structure of the retina. This correlated with morphological alterations of thyroid follicles as revealed by use of a transgenic zebrafish line. Interestingly, effects were partly reversible after a recovery period as short as 3 days. Results are consistent with changes in TH levels measured in different tissues of the embryos, for example, in the eyes. The results show that eye development in zebrafish embryos is very sensitive to THSDC treatment but able to recover quickly from early exposure by effective repair mechanisms. Environ Toxicol Chem 2023;42:1276-1292. © 2023 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.
Collapse
Affiliation(s)
- Pauline Pannetier
- Aquatic Ecology & Toxicology, Center for Organismal Studies, University of Heidelberg, Heidelberg, Germany
| | - Rikke Poulsen
- Environmental Metabolomics Laboratory, Department of Environmental Science, University of Aarhus, Aarhus, Denmark
| | - Lisa Gölz
- Aquatic Ecology & Toxicology, Center for Organismal Studies, University of Heidelberg, Heidelberg, Germany
| | - Sara Coordes
- Aquatic Ecology & Toxicology, Center for Organismal Studies, University of Heidelberg, Heidelberg, Germany
| | - Hanna Stegeman
- Aquatic Ecology & Toxicology, Center for Organismal Studies, University of Heidelberg, Heidelberg, Germany
| | - Johannes Koegst
- Aquatic Ecology & Toxicology, Center for Organismal Studies, University of Heidelberg, Heidelberg, Germany
| | - Luisa Reger
- Aquatic Ecology & Toxicology, Center for Organismal Studies, University of Heidelberg, Heidelberg, Germany
| | - Thomas Braunbeck
- Aquatic Ecology & Toxicology, Center for Organismal Studies, University of Heidelberg, Heidelberg, Germany
| | - Martin Hansen
- Environmental Metabolomics Laboratory, Department of Environmental Science, University of Aarhus, Aarhus, Denmark
| | - Lisa Baumann
- Aquatic Ecology & Toxicology, Center for Organismal Studies, University of Heidelberg, Heidelberg, Germany
- Amsterdam Institute for Life and Environment (A-LIFE), Section on Environmental Health & Toxicology, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| |
Collapse
|
5
|
von Hellfeld R, Gade C, Baumann L, Leist M, Braunbeck T. The sensitivity of the zebrafish embryo coiling assay for the detection of neurotoxicity by compounds with diverse modes of action. Environ Sci Pollut Res Int 2023:10.1007/s11356-023-27662-2. [PMID: 37213015 DOI: 10.1007/s11356-023-27662-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Accepted: 05/11/2023] [Indexed: 05/23/2023]
Abstract
In the aim to determine neurotoxicity, new methods are being validated, including tests and test batteries comprising in vitro and in vivo approaches. Alternative test models such as the zebrafish (Danio rerio) embryo have received increasing attention, with minor modifications of the fish embryo toxicity test (FET; OECD TG 236) as a tool to assess behavioral endpoints related to neurotoxicity during early developmental stages. The spontaneous tail movement assay, also known as coiling assay, assesses the development of random movement into complex behavioral patterns and has proven sensitive to acetylcholine esterase inhibitors at sublethal concentrations. The present study explored the sensitivity of the assay to neurotoxicants with other modes of action (MoAs). Here, five compounds with diverse MoAs were tested at sublethal concentrations: acrylamide, carbaryl, hexachlorophene, ibuprofen, and rotenone. While carbaryl, hexachlorophene, and rotenone consistently induced severe behavioral alterations by ~ 30 h post fertilization (hpf), acrylamide and ibuprofen expressed time- and/or concentration-dependent effects. At 37-38 hpf, additional observations revealed behavioral changes during dark phases with a strict concentration-dependency. The study documented the applicability of the coiling assay to MoA-dependent behavioral alterations at sublethal concentrations, underlining its potential as a component of a neurotoxicity test battery.
Collapse
Affiliation(s)
- Rebecca von Hellfeld
- School of Biological Sciences, University of Aberdeen, 23 St Machar Drive, Aberdeen, AB24 3UK, UK.
- National Decommissioning Centre, Main Street, Ellon, AB41 6AA, UK.
- Aquatic Ecology and Toxicology, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, 69120, Heidelberg, Germany.
| | - Christoph Gade
- School of Biological Sciences, University of Aberdeen, 23 St Machar Drive, Aberdeen, AB24 3UK, UK
- National Decommissioning Centre, Main Street, Ellon, AB41 6AA, UK
- Aquatic Ecology and Toxicology, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, 69120, Heidelberg, Germany
| | - Lisa Baumann
- Aquatic Ecology and Toxicology, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, 69120, Heidelberg, Germany
- Faculty of Science, Environmental Health & Toxicology, Vrije Universiteit Amsterdam, De Boelelaan 1105, 1081 HV, Amersterdam, Netherlands
| | - Marcel Leist
- In Vitro Toxicology and Biomedicine, Department Inaugurated By the Doerenkamp-Zbinden Foundation, University of Konstanz, Universitätsstraße 10, 78464, Constance, Germany
| | - Thomas Braunbeck
- Aquatic Ecology and Toxicology, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, 69120, Heidelberg, Germany
| |
Collapse
|
6
|
Kämmer N, Reimann T, Ovcharova V, Braunbeck T. A novel automated method for the simultaneous detection of breathing frequency and amplitude in zebrafish (Danio rerio) embryos and larvae. Aquat Toxicol 2023; 258:106493. [PMID: 36963131 DOI: 10.1016/j.aquatox.2023.106493] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2023] [Revised: 03/09/2023] [Accepted: 03/10/2023] [Indexed: 06/18/2023]
Abstract
Stress responses of fish to disruption of oxygen homeostasis include adjusted oxygen consumption rate (MO2) as well as the hyperventilation consisting of changes in breathing frequency (fv) and amplitude (fampl). However, studying the HVR in very small organisms such as zebrafish (Danio rerio) embryos and larvae is challenging, and breathing movements (i.e., fv) are usually manually counted, which is time- and human resource-intense, error-prone and does not provide information on the amplitude of breathing movements of the response, the breathing amplitude (fampl). Hence, in the present study, a new automated method was developed to simultaneously measure fv and fampl in small zebrafish embryos and larvae with the computer software DanioScope™. To compare HVR strategies at different life-stages of zebrafish and the physiologically linked MO2, hatched 4 d old embryos and early gill-breathing 12 d old larvae were treated with the HVR-inducing neurotoxic compound lindane (γ-hexachlorocyclohexane; γ-HCH) as a model substance. Comparison of manually counted fv with fv data measured by DanioScope™ at both life-stages showed high to moderate agreement between the two methods with respect to fv in control fish and in fish treated with lower lindane concentrations (3 - 18% deviation at 25 µg/L γ-HCH). With increasing lindane concentrations (100 and 400 µg/L γ-HCH), however, manual counts showed an average underestimation of fv by up to 30%, mainly due to very fast, rapidly successive, and indistinct movements of the fish, which cannot be properly detected by manual counts. Automated measurement thus proved significantly more sensitive, although several pre- and post-processing steps are needed. The improved automated detection of fv and the first reliable estimation of fampl in small fish embryos and larvae, as well as the inclusion of MO2, may provide new insights into different respiratory strategies and may, thus, represent a tool to lower the detection limit for reactions of different life-stages of fish to environmental stressors. In the present study, this became evident, as early gill-breathing 12 d old zebrafish larvae showed symptoms of respiratory failure (i.e., increase in fv, fampl and MO2, followed by subsequent lethargy) after exposure to lindane, whereas skin-breathing in 4 d old embryos proved mainly insensitive to the paralytic effects of lindane.
Collapse
Affiliation(s)
- Nadine Kämmer
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, Heidelberg D-69210, Germany.
| | - Tanja Reimann
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, Heidelberg D-69210, Germany
| | - Viktoriia Ovcharova
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, Heidelberg D-69210, Germany
| | - Thomas Braunbeck
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, Heidelberg D-69210, Germany.
| |
Collapse
|
7
|
Kraft M, Gölz L, Rinderknecht M, Koegst J, Braunbeck T, Baumann L. Developmental exposure to triclosan and benzophenone-2 causes morphological alterations in zebrafish (Danio rerio) thyroid follicles and eyes. Environ Sci Pollut Res Int 2023; 30:33711-33724. [PMID: 36495432 PMCID: PMC9736712 DOI: 10.1007/s11356-022-24531-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Accepted: 11/28/2022] [Indexed: 05/31/2023]
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.
Collapse
Affiliation(s)
- Maximilian Kraft
- Aquatic Toxicology and Ecology Section, Centre of Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, 69120, Heidelberg, Germany
| | - Lisa Gölz
- Aquatic Toxicology and Ecology Section, Centre of Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, 69120, Heidelberg, Germany
| | - Maximilian Rinderknecht
- Aquatic Toxicology and Ecology Section, Centre of Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, 69120, Heidelberg, Germany
| | - Johannes Koegst
- Aquatic Toxicology and Ecology Section, Centre of Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, 69120, Heidelberg, Germany
| | - Thomas Braunbeck
- Aquatic Toxicology and Ecology Section, Centre of Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, 69120, Heidelberg, Germany
| | - Lisa Baumann
- Aquatic Toxicology and Ecology Section, Centre of Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, 69120, Heidelberg, Germany.
| |
Collapse
|
8
|
Frese L, Braunbeck T. Adapting classic paradigms to analyze alterations of shoal-wide behavior in early-life stages of zebrafish (Danio rerio) - A case study with fluoxetine. Neurotoxicol Teratol 2023; 95:107136. [PMID: 36423854 DOI: 10.1016/j.ntt.2022.107136] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 11/01/2022] [Accepted: 11/13/2022] [Indexed: 11/23/2022]
Abstract
Given the strong increase in prescription of neuroactive pharmaceuticals, neurotoxicity has received growing concern in science and the public. Regulatory requirements stimulated the development of new methods to evaluate the risk of neurotoxic substances for humans and the environment, and, with respect to potential damage to aquatic ecosystems, a variety of behavior-based assays have been proposed for neurotoxicity testing, most of which, however, are restricted to changes in the behavior of individual fish. Since many fish species form shoals under natural conditions, this may cause important aspects of behavior to be overlooked and there is a need for behavior assays integrating individual behavior with behavior of the entire swarm. In order to combine more environmentally realistic sub-chronic exposure scenarios with undistorted social behavior and animal welfare considerations, two behavioral assays are proposed that might be integrated into early-life stage toxicity studies according to OECD TG 210, which are commonly run for a multitude of regulations: To this end, protocols for a novel tank test and a predator response assay were adapted to also record the behavior of free-swimming zebrafish (Danio rerio) juveniles within shoals. Comparisons of the diving response (novel tank) or the shoal's coherence and position relative to the stimulus (predator) with control groups allow conclusions about the anxiety state of the fish, which might well have an impact on survival chances in the wild. As a model substance, the antidepressant fluoxetine ((RS)-N-Methyl-3-phenyl-3-(4-trifluoromethylphenoxy)propylamine) produced adverse effects down to concentrations three orders of magnitude below the EC10 from acute fish embryo toxicity tests according to OECD TG 236. With the integration of such behavior tests into OECD TG 210, important population-relevant information on potential neurotoxicity can be collected without increasing the number of experimental animals.
Collapse
Affiliation(s)
- Lukas Frese
- Aquatic Ecology and Toxicology Group, Center for Organismal Studies, Heidelberg University, Im Neuenheimer Feld 504, D-69120 Heidelberg, Germany.
| | - Thomas Braunbeck
- Aquatic Ecology and Toxicology Group, Center for Organismal Studies, Heidelberg University, Im Neuenheimer Feld 504, D-69120 Heidelberg, Germany.
| |
Collapse
|
9
|
Gölz L, Baumann L, Pannetier P, Braunbeck T, Knapen D, Vergauwen L. AOP Report: Thyroperoxidase Inhibition Leading to Altered Visual Function in Fish Via Altered Retinal Layer Structure. Environ Toxicol Chem 2022; 41:2632-2648. [PMID: 35942927 DOI: 10.1002/etc.5452] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Accepted: 07/29/2022] [Indexed: 06/15/2023]
Abstract
Thyroid hormones (THs) are involved in the regulation of many important physiological and developmental processes, including vertebrate eye development. Thyroid hormone system-disrupting chemicals (THSDCs) may have severe consequences, because proper functioning of the visual system is a key factor for survival in wildlife. However, the sequence of events leading from TH system disruption (THSD) to altered eye development in fish has not yet been fully described. The development of this adverse outcome pathway (AOP) was based on an intensive literature review of studies that focused on THSD and impacts on eye development, mainly in fish. In total, approximately 120 studies (up to the end of 2021) were used in the development of this AOP linking inhibition of the key enzyme for TH synthesis, thyroperoxidase (TPO), to effects on retinal layer structure and visual function in fish (AOP-Wiki, AOP 363). In a weight-of-evidence evaluation, the confidence levels were overall moderate, with ample studies showing the link between reduced TH levels and altered retinal layer structure. However, some uncertainties about the underlying mechanism(s) remain. Although the current weight-of-evidence evaluation is based on fish, the AOP is plausibly applicable to other vertebrate classes. Through the re-use of several building blocks, this AOP is connected to the AOPs leading from TPO and deiodinase inhibition to impaired swim bladder inflation in fish (AOPs 155-159), together forming an AOP network describing THSD in fish. This AOP network addresses the lack of thyroid-related endpoints in existing fish test guidelines for the evaluation of THSDCs. Environ Toxicol Chem 2022;41:2632-2648. © 2022 SETAC.
Collapse
Affiliation(s)
- Lisa Gölz
- Aquatic Ecology and Toxicology Research Group, Centre for Organismal Studies, University of Heidelberg, Heidelberg, Germany
| | - Lisa Baumann
- Aquatic Ecology and Toxicology Research Group, Centre for Organismal Studies, University of Heidelberg, Heidelberg, Germany
| | - Pauline Pannetier
- Aquatic Ecology and Toxicology Research Group, Centre for Organismal Studies, University of Heidelberg, Heidelberg, Germany
| | - Thomas Braunbeck
- Aquatic Ecology and Toxicology Research Group, Centre for Organismal Studies, University of Heidelberg, Heidelberg, Germany
| | - Dries Knapen
- Zebrafishlab, Veterinary Physiology and Biochemistry, Department of Veterinary Sciences, University of Antwerp, Wilrijk, Belgium
| | - Lucia Vergauwen
- Zebrafishlab, Veterinary Physiology and Biochemistry, Department of Veterinary Sciences, University of Antwerp, Wilrijk, Belgium
| |
Collapse
|
10
|
Brotzmann K, Escher SE, Walker P, Braunbeck T. Potential of the zebrafish (Danio rerio) embryo test to discriminate between chemicals of similar molecular structure-a study with valproic acid and 14 of its analogues. Arch Toxicol 2022; 96:3033-3051. [PMID: 35920856 PMCID: PMC9525359 DOI: 10.1007/s00204-022-03340-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Accepted: 07/13/2022] [Indexed: 12/01/2022]
Abstract
Valproic acid is a frequently used antiepileptic drug and known pediatric hepatotoxic agent. In search of pharmaceuticals with increased effectiveness and reduced toxicity, analogue chemicals came into focus. So far, toxicity and teratogenicity data of drugs and metabolites have usually been collected from mammalian model systems such as mice and rats. However, in an attempt to reduce mammalian testing while maintaining the reliability of toxicity testing of new industrial chemicals and drugs, alternative test methods are being developed. To this end, the potential of the zebrafish (Danio rerio) embryo to discriminate between valproic acid and 14 analogues was investigated by exposing zebrafish embryos for 120 h post fertilization in the extended version of the fish embryo acute toxicity test (FET; OECD TG 236), and analyzing liver histology to evaluate the correlation of liver effects and the molecular structure of each compound. Although histological evaluation of zebrafish liver did not identify steatosis as the prominent adverse effect typical in human and mice, the structure–activity relationship (SAR) derived was comparable not only to human HepG2 cells, but also to available in vivo mouse and rat data. Thus, there is evidence that zebrafish embryos might serve as a tool to bridge the gap between subcellular, cell-based systems and vertebrate models.
Collapse
Affiliation(s)
- Katharina Brotzmann
- Aquatic Ecology and Toxicology Group, Center for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, 69120, Heidelberg, Germany.
| | - Sylvia E Escher
- Fraunhofer Institute for Toxicology and Experimental Medicine (ITEM), Nikolai-Fuchs-Strasse 1, 30625, Hannover, Germany
| | - Paul Walker
- Cyprotex Discovery, No. 24 Mereside, Alderley Park, Nether Alderley, Cheshire, SK10 4TG, UK
| | - Thomas Braunbeck
- Aquatic Ecology and Toxicology Group, Center for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, 69120, Heidelberg, Germany.
| |
Collapse
|
11
|
Kämmer N, Erdinger L, Braunbeck T. The onset of active gill respiration in post-embryonic zebrafish (Danio rerio) larvae triggers an increased sensitivity to neurotoxic compounds. Aquat Toxicol 2022; 249:106240. [PMID: 35863251 DOI: 10.1016/j.aquatox.2022.106240] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Revised: 07/10/2022] [Accepted: 07/11/2022] [Indexed: 06/15/2023]
Abstract
Originally designed as a general alternative to acute fish toxicity testing (AFT), the fish embryo toxicity test (FET) has become subject to concerns with respect to neurotoxic substances. Whereas oxygen uptake in the fish embryo primarily occurs via diffusion across the skin, juvenile and adult fish rely on active ventilation of the gills. As a consequence, substances including, e.g., neurotoxicants which prevent appropriate ventilation of gills ("respiratory failure syndrome") might lead to suffocation in juvenile and adult fish, but not in skin-breathing embryos. To investigate if this respiratory failure syndrome might play a role for the higher sensitivity of juvenile and adult fish to neurotoxicants, a modified acute toxicity test using post-embryonic, early gill-breathing life-stages of zebrafish was developed with chlorpyrifos, permethrin, lindane, aldicarb, ziram and aniline as test substances. Additionally, a comparative study into bioaccumulation of lipophilic substances with logKow > 3.5 and swimbladder deflation as potential side effects of the respiratory failure syndrome was performed with 4 d old skin-breathing and 12 d old gill-breathing zebrafish. With respect to acute toxicity, post-embryonic 12 d larvae proved to be more sensitive than both embryos (FET) and adult zebrafish (AFT) to all test substances except for permethrin. Accumulation of chlorpyrifos, lindane and permethrin was 1.3- to 5-fold higher in 4 d old than in 12 d old zebrafish, suggesting that (intermediate) storage of substances in the yolk might reduce bioavailability and prevent metabolization, which could be a further reason for lower toxicity in 4 d than in 12 d old zebrafish. Whereas ziram and aniline showed no significant effect on the swimbladder, zebrafish exposed to chlorpyrifos, lindane and permethrin showed significantly deflated swimbladders in 12 d old larvae; in the case of aldicarb, there was a significant hyperinflation in 4 d old larvae. Swimbladder deflation in post-embryonic 12 d zebrafish larvae might be hypothesized as a reason for a lack of internal oxygen supplies during the respiratory failure syndrome, whereas in 4 d old embryos cholinergic hyperinflation of the swimbladder dominates over other effects. Regarding acute lethality, the study provides further evidence that the switch from transcutaneous to branchial respiration in post-embryonic zebrafish life-stages might be the reason for the higher sensitivity of juvenile and adult fish to neurotoxic substances.
Collapse
Affiliation(s)
- Nadine Kämmer
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, Heidelberg D-69210, Germany.
| | - Lothar Erdinger
- Department of Medical Microbiology and Hygiene, Im Neuenheimer Feld 324, Heidelberg D-69120, Germany
| | - Thomas Braunbeck
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, Heidelberg D-69210, Germany.
| |
Collapse
|
12
|
Wlodkowic D, Bownik A, Leitner C, Stengel D, Braunbeck T. Beyond the behavioural phenotype: Uncovering mechanistic foundations in aquatic eco-neurotoxicology. Sci Total Environ 2022; 829:154584. [PMID: 35306067 DOI: 10.1016/j.scitotenv.2022.154584] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2022] [Revised: 03/09/2022] [Accepted: 03/11/2022] [Indexed: 06/14/2023]
Abstract
During the last decade, there has been an increase in awareness of how anthropogenic pollution can alter behavioural traits of diverse aquatic organisms. Apart from understanding profound ecological implications, alterations in neuro-behavioural indices have emerged as sensitive and physiologically integrative endpoints in chemical risk assessment. Accordingly, behavioural ecotoxicology and broader eco-neurotoxicology are becoming increasingly popular fields of research that span a plethora of fundamental laboratory experimentations as well as applied field-based studies. Despite mounting interest in aquatic behavioural ecotoxicology studies, there is, however, a considerable paucity in deciphering the mechanistic foundations underlying behavioural alterations upon exposure to pollutants. The behavioural phenotype is indeed the highest-level integrative neurobiological phenomenon, but at its core lie myriads of intertwined biochemical, cellular, and physiological processes. Therefore, the mechanisms that underlie changes in behavioural phenotypes can stem among others from dysregulation of neurotransmitter pathways, electrical signalling, and cell death of discrete cell populations in the central and peripheral nervous systems. They can, however, also be a result of toxicity to sensory organs and even metabolic dysfunctions. In this critical review, we outline why behavioural phenotyping should be the starting point that leads to actual discovery of fundamental mechanisms underlying actions of neurotoxic and neuromodulating contaminants. We highlight potential applications of the currently existing and emerging neurobiology and neurophysiology analytical strategies that should be embraced and more broadly adopted in behavioural ecotoxicology. Such strategies can provide new mechanistic discoveries instead of only observing the end sum phenotypic effects.
Collapse
Affiliation(s)
- Donald Wlodkowic
- The Neurotox Laboratory, School of Science, RMIT University, Melbourne, Australia.
| | - Adam Bownik
- Department of Hydrobiology and Protection of Ecosystems, Faculty of Environmental Biology, University of Life Sciences, Lublin, Poland
| | - Carola Leitner
- Aquatic Ecology and Toxicology, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, D-69120 Heidelberg, Germany
| | - Daniel Stengel
- Aquatic Ecology and Toxicology, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, D-69120 Heidelberg, Germany
| | - Thomas Braunbeck
- Aquatic Ecology and Toxicology, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, D-69120 Heidelberg, Germany
| |
Collapse
|
13
|
Hanslik L, Huppertsberg S, Kämmer N, Knepper TP, Braunbeck T. Rethinking the relevance of microplastics as vector for anthropogenic contaminants: Adsorption of toxicants to microplastics during exposure in a highly polluted stream - Analytical quantification and assessment of toxic effects in zebrafish (Danio rerio). Sci Total Environ 2022; 816:151640. [PMID: 34774627 DOI: 10.1016/j.scitotenv.2021.151640] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Revised: 11/01/2021] [Accepted: 11/08/2021] [Indexed: 06/13/2023]
Abstract
Given the increasing amounts of plastic debris entering marine and freshwater ecosystems, there is a growing demand for environmentally relevant exposure scenarios to improve the risk assessment of microplastic particles (MPs) in aquatic environments. So far, data on adverse effects in aquatic organisms induced by naturally exposed MPs are scarce and controversially discussed. As a consequence, we investigated the potential role of MPs regarding the sorption and transfer of environmental contaminants under natural conditions. For this end, a mixture of four common polymer types (polyethylene, polypropylene, polystyrene, polyvinyl chloride) was exposed to natural surface water in a polluted stream for three weeks. Samples of water, MP mixture, sediment, and suspended matter were target-screened for the presence of pollutants using GC/LC-MS, resulting in up to 94 different compounds. Possible adverse effects were investigated using several biomarkers in early developmental stages of zebrafish (Danio rerio). Exposure to natural stream water samples significantly inhibited acetylcholinesterase activity, altered CYP450 induction and modified behavioral patterns of zebrafish. In contrast, effects by samples of both non-exposed MPs and exposed MPs in zebrafish were less prominent than effects by water samples. In fact, the analytical target screening documented only few compounds sorbed to natural particles and MPs. Regarding acute toxic effects, no clear differentiation between different MPs and natural particles could be made, suggesting that - upon exposure in natural water bodies - MPs seem to approximate the sorption behavior of natural particles, presumably to a large extent due to biofilm formation. Thus, if compared to natural inorganic particles, MPs most likely do not transfer elevated amounts of environmental pollutants to biota and, therefore, do not pose a specific additional threat to aquatic organisms.
Collapse
Affiliation(s)
- Lisa Hanslik
- Aquatic Ecology and Toxicology Group, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, Heidelberg, D-69120, Germany.
| | - Sven Huppertsberg
- Hochschule Fresenius GmbH, University of Applied Sciences Fresenius, Limburger Str. 2, Idstein, D-65510, Germany
| | - Nadine Kämmer
- Aquatic Ecology and Toxicology Group, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, Heidelberg, D-69120, Germany
| | - Thomas P Knepper
- Hochschule Fresenius GmbH, University of Applied Sciences Fresenius, Limburger Str. 2, Idstein, D-65510, Germany
| | - Thomas Braunbeck
- Aquatic Ecology and Toxicology Group, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, Heidelberg, D-69120, Germany.
| |
Collapse
|
14
|
Hanslik L, Seiwert B, Huppertsberg S, Knepper TP, Reemtsma T, Braunbeck T. Biomarker responses in zebrafish (Danio rerio) following long-term exposure to microplastic-associated chlorpyrifos and benzo(k)fluoranthene. Aquat Toxicol 2022; 245:106120. [PMID: 35183844 DOI: 10.1016/j.aquatox.2022.106120] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 01/20/2022] [Accepted: 02/12/2022] [Indexed: 06/14/2023]
Abstract
Continuously increasing plastic production causes a constant accumulation of microplastic particles (MPs) in the aquatic environment, especially in industrialized and urbanized areas with elevated wastewater discharges. This coincides with the release of persistent organic pollutants (polycyclic aromatic hydrocarbons (PAHs), pesticides) entering limnic ecosystems. Although the assessment of potential effects of environmental pollutants sorbed to MPs under chronic exposure scenarios seems vital, data on potential hazards and risk by combined exposure to pollutants and microplastics for aquatic vertebrates is still limited. Therefore, zebrafish (Danio rerio) were exposed over 21 days to the organophosphate insecticide chlorpyrifos (CPF; 10 and 100 ng/L) and the PAH benzo(k)fluoranthene (BkF; 0.78 and 50 µg/L) either dissolved directly in water or sorbed to different MPs (irregular polystyrene, spherical polymethyl methacrylate; ≤ 100 µm), where CPF was sorbed to polystyrene MPs and BkF was sorbed to polymethyl methacrylate MPs. Contaminant sorption to MPs and leaching were documented using GC-EI-MS; potential accumulation was studied in cryosections of the gastrointestinal tract. Enzymatic biomarkers and biotransformation were measured in liver and brain. Overall, exposure to non-contaminated MPs did not induce any adverse effects. Results of fluorescence tracking, CYP1A modulation by BkF as well as changes in acetylcholinesterase activity (AChE) by CPF were less pronounced when contaminants were sorbed to MPs, indicating reduced bioavailability of pollutants. Overall, following exposure to waterborne BkF, only minor amounts of parent BkF and biotransformation products were detected in zebrafish liver. Even high loads of MPs and sorbed contaminants did not induce adverse effects in zebrafish; thus, the potential threat of MPs as vectors for contaminant transfer in limnic ecosystems can be considered limited.
Collapse
Affiliation(s)
- Lisa Hanslik
- Aquatic Ecology and Toxicology Group, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, Heidelberg d-69120, Germany.
| | - Bettina Seiwert
- Department of Analytical Chemistry, Helmholtz Centre for Environmental Research - UFZ, Permoserstrasse 15, Leipzig d-04318, Germany
| | - Sven Huppertsberg
- Hochschule Fresenius GmbH, University of Applied Sciences Fresenius, Limburger Str. 2, Idstein d-65510, Germany
| | - Thomas P Knepper
- Hochschule Fresenius GmbH, University of Applied Sciences Fresenius, Limburger Str. 2, Idstein d-65510, Germany
| | - Thorsten Reemtsma
- Department of Analytical Chemistry, Helmholtz Centre for Environmental Research - UFZ, Permoserstrasse 15, Leipzig d-04318, Germany
| | - Thomas Braunbeck
- Aquatic Ecology and Toxicology Group, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, Heidelberg d-69120, Germany.
| |
Collapse
|
15
|
von Hellfeld R, Pannetier P, Braunbeck T. Specificity of time- and dose-dependent morphological endpoints in the fish embryo acute toxicity (FET) test for substances with diverse modes of action: the search for a "fingerprint". Environ Sci Pollut Res Int 2022; 29:16176-16192. [PMID: 34643865 PMCID: PMC8827326 DOI: 10.1007/s11356-021-16354-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Accepted: 09/01/2021] [Indexed: 06/13/2023]
Abstract
The fish embryo acute toxicity (FET) test with the zebrafish (Danio rerio) embryo according to OECD TG 236 was originally developed as an alternative test method for acute fish toxicity testing according to, e.g., OECD TG 203. Given the versatility of the protocol, however, the FET test has found application beyond acute toxicity testing as a common tool in environmental hazard and risk assessment. Whereas the standard OECD guideline is restricted to four core endpoints (coagulation as well as lack of somite formation, heartbeat, and tail detachment) for simple, rapid assessment of acute toxicity, further endpoints can easily be integrated into the FET test protocol. This has led to the hypothesis that an extended FET test might allow for the identification of different classes of toxicants via a "fingerprint" of morphological observations. To test this hypothesis, the present study investigated a set of 18 compounds with highly diverse modes of action with respect to acute and sublethal endpoints. Especially at higher concentrations, most observations proved toxicant-unspecific. With decreasing concentrations, however, observations declined in number, but gained in specificity. Specific observations may at best be made at test concentrations ≤ EC10. The existence of a "fingerprint" based on morphological observations in the FET is, therefore, highly unlikely in the range of acute toxicity, but cannot be excluded for experiments at sublethal concentrations.
Collapse
Affiliation(s)
- Rebecca von Hellfeld
- Center for Organismal Studies, Aquatic Ecology and Toxicology Section, University of Heidelberg, Im Neuenheimer Feld 504, 69120, Heidelberg, Germany.
- University of Aberdeen, Institute of Biological and Environmental Science, 23 St Machar Drive, AB24 3UU, Aberdeen, UK.
| | - Pauline Pannetier
- Center for Organismal Studies, Aquatic Ecology and Toxicology Section, University of Heidelberg, Im Neuenheimer Feld 504, 69120, Heidelberg, Germany
| | - Thomas Braunbeck
- Center for Organismal Studies, Aquatic Ecology and Toxicology Section, University of Heidelberg, Im Neuenheimer Feld 504, 69120, Heidelberg, Germany.
| |
Collapse
|
16
|
Von Hellfeld R, Ovcharova V, Bevan S, Lazaridi MA, Bauch C, Walker P, Hougaard Bennekou S, Forsby A, Braunbeck T. Zebrafish embryo neonicotinoid developmental neurotoxicity in the FET test and behavioral assays. ALTEX 2022; 39:367–387. [PMID: 35229877 DOI: 10.14573/altex.2111021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 02/21/2022] [Indexed: 06/14/2023]
Abstract
The need for reliable, sensitive (developmental) neurotoxicity testing of chemicals has steadily increased. Given the limited capacities for routine testing according to accepted regulatory guidelines, there is potential risk to human health and the environment. Most toxicity studies are based on mammalian test systems, which have been questioned for low sensitivity, limited relevance for humans, and animal welfare considerations. This increased the need for alternative models, one of which is the zebrafish (Danio rerio) embryo. This study assessed selected neonicotinoids at sub-lethal concentrations for their effects on embryonic development and behavior. The fish embryo acute toxicity test (OECD TG 236) determined the lowest observable effective concentrations, which were used as the highest test concentrations in subsequent behavioral assays. In the FET test, no severe compound-induced sublethal effects were seen at < 100 µM. In the coiling assay, exposure to ≥ 1.25 µM nicotine (positive control) affected both the burst duration and burst count per minute, whereas ≥ 50 µM thiacloprid affected the mean burst duration. Exposure to ≥ 50 µM acetamiprid and imidacloprid induced significant alterations in both mean burst duration and burst count per minute. In the swimming assay, 100 µM acetamiprid induced alterations in the frequency and extent of movements, whilst nicotine exposure only induced non-significant changes. All behavioral changes could be correlated to findings in mammalian studies. Given the quest for alternative test methods of (developmental) neurotoxicity, zebrafish embryo behavior testing could be integrated into a future tiered testing scheme.
Collapse
Affiliation(s)
- Rebecca Von Hellfeld
- Aquatic Ecology and Toxicology, Centre for Organismal Studies, University of Heidelberg, Heidelberg, Germany
- Current address: School of Biological Sciences, University of Aberdeen, Aberdeen, United Kingdom
| | - Viktoriia Ovcharova
- Aquatic Ecology and Toxicology, Centre for Organismal Studies, University of Heidelberg, Heidelberg, Germany
- iES Landau, Institute for Environmental Sciences, University of Koblenz-Landau, Landau, Germany
| | | | | | | | - Paul Walker
- Cyprotex Discovery Limited, Cheshire, United Kingdom
| | | | - Anna Forsby
- Department of Biochemistry and Biophysics, Svante Arrhenius Laboratories for Natural Sciences, Stockholm University, Stockholm, Sweden
| | - Thomas Braunbeck
- Aquatic Ecology and Toxicology, Centre for Organismal Studies, University of Heidelberg, Heidelberg, Germany
| |
Collapse
|
17
|
Escher SE, Aguayo-Orozco A, Benfenati E, Bitsch A, Braunbeck T, Brotzmann K, Bois F, van der Burg B, Castel J, Exner T, Gadaleta D, Gardner I, Goldmann D, Hatley O, Golbamaki N, Graepel R, Jennings P, Limonciel A, Long A, Maclennan R, Mombelli E, Norinder U, Jain S, Capinha LS, Taboureau OT, Tolosa L, Vrijenhoek NG, van Vugt-Lussenburg BMA, Walker P, van de Water B, Wehr M, White A, Zdrazil B, Fisher C. A read-across case study on chronic toxicity of branched carboxylic acids (1): Integration of mechanistic evidence from new approach methodologies (NAMs) to explore a common mode of action. Toxicol In Vitro 2021; 79:105269. [PMID: 34757180 DOI: 10.1016/j.tiv.2021.105269] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 10/17/2021] [Accepted: 10/27/2021] [Indexed: 02/04/2023]
Abstract
This read-across case study characterises thirteen, structurally similar carboxylic acids demonstrating the application of in vitro and in silico human-based new approach methods, to determine biological similarity. Based on data from in vivo animal studies, the read-across hypothesis is that all analogues are steatotic and so should be considered hazardous. Transcriptomic analysis to determine differentially expressed genes (DEGs) in hepatocytes served as first tier testing to confirm a common mode-of-action and identify differences in the potency of the analogues. An adverse outcome pathway (AOP) network for hepatic steatosis, informed the design of an in vitro testing battery, targeting AOP relevant MIEs and KEs, and Dempster-Shafer decision theory was used to systematically quantify uncertainty and to define the minimal testing scope. The case study shows that the read-across hypothesis is the critical core to designing a robust, NAM-based testing strategy. By summarising the current mechanistic understanding, an AOP enables the selection of NAMs covering MIEs, early KEs, and late KEs. Experimental coverage of the AOP in this way is vital since MIEs and early KEs alone are not confirmatory of progression to the AO. This strategy exemplifies the workflow previously published by the EUTOXRISK project driving a paradigm shift towards NAM-based NGRA.
Collapse
Affiliation(s)
- Sylvia E Escher
- Fraunhofer Institute for Toxicology and Experimental Medicine, Chemical Safety and Toxicology, Germany.
| | | | - Emilio Benfenati
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Milano, Italy
| | - Annette Bitsch
- Fraunhofer Institute for Toxicology and Experimental Medicine, Chemical Safety and Toxicology, Germany
| | - Thomas Braunbeck
- Aquatic Ecology and Toxicology Group, Center for Organismal Studies, University of Heidelberg, Heidelberg, Germany
| | - Katharina Brotzmann
- Aquatic Ecology and Toxicology Group, Center for Organismal Studies, University of Heidelberg, Heidelberg, Germany
| | - Frederic Bois
- Certara UK Ltd, Simcyp Division, Sheffield, United Kingdom
| | | | - Jose Castel
- Instituto de Investigación Sanitaria La Fe, Valencia, Spain
| | | | - Domenico Gadaleta
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Milano, Italy
| | - Iain Gardner
- Certara UK Ltd, Simcyp Division, Sheffield, United Kingdom
| | - Daria Goldmann
- University of Vienna, Department of Pharmaceutical Sciences, Division of Pharmaceutical Chemistry, Vienna, Austria
| | - Oliver Hatley
- Certara UK Ltd, Simcyp Division, Sheffield, United Kingdom
| | | | - Rabea Graepel
- Leiden Academic Centre for Drug Research (LACDR), Leiden University, Leiden, the Netherlands
| | - Paul Jennings
- Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | | | | | | | | | | | - Sankalp Jain
- University of Vienna, Department of Pharmaceutical Sciences, Division of Pharmaceutical Chemistry, Vienna, Austria
| | | | | | - Laia Tolosa
- Instituto de Investigación Sanitaria La Fe, Valencia, Spain
| | - Nanette G Vrijenhoek
- Leiden Academic Centre for Drug Research (LACDR), Leiden University, Leiden, the Netherlands
| | | | | | - Bob van de Water
- Leiden Academic Centre for Drug Research (LACDR), Leiden University, Leiden, the Netherlands
| | - Matthias Wehr
- Fraunhofer Institute for Toxicology and Experimental Medicine, Chemical Safety and Toxicology, Germany
| | - Andrew White
- Unilever Safety and Environmental Assurance Centre, Sharnbrook, Bedfordshire, United Kingdom
| | - Barbara Zdrazil
- University of Vienna, Department of Pharmaceutical Sciences, Division of Pharmaceutical Chemistry, Vienna, Austria
| | - Ciarán Fisher
- Certara UK Ltd, Simcyp Division, Sheffield, United Kingdom
| |
Collapse
|
18
|
Chen X, Cheng SH, Kinoshita M, de Witte PA, Liu J, Hinton D, Braunbeck T, Cotgreave I, Schlenk D, Gong Z, El-Nezami H, Ho KC, Chan KF, Xu S, Yiu PY, Zhang H, Wu D, Chan YS, Ny A, Maes J. Pre-validation of choriogenin H transgenic medaka eleutheroembryos as a quantitative estrogenic activity test method. Anal Biochem 2021; 629:114311. [PMID: 34302800 DOI: 10.1016/j.ab.2021.114311] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2021] [Revised: 06/23/2021] [Accepted: 07/18/2021] [Indexed: 11/16/2022]
Abstract
The choriogenin H - EGFP transgenic medaka (Oryzias melastigma) has been used to test estrogenic substances and quantify estrogenic activity into 17β-estradiol (E2) equivalency (EEQ). The method uses 8 eleutheroembryos in 2 ml solution per well and 3 wells per treatment in 24-well plates at 26 ± 1 °C for 24 ± 2 h, with subsequent measurements of induced GFP signal intensity. EEQ measurements are calculated using a E2 probit regression model with a coefficient of determination (R2) > 0.90. The selectivity was confirmed evaluating 27 known estrogenic and 5 known non-estrogenic compounds. Limit of quantitation (LOQ), recovery rate and bias were calculated to be 1 ng/ml EEQ, 104% and 4% respectively. Robustness analysis revealed exposure temperature is a sensitive parameter that should be kept at 26 ± 1 °C. The repeatability of intra- and inter-laboratories achieved CV < 30% for most tested food and cosmetics samples. The lot-lot stability was confirmed by the stable EEQ qualitative control (QC, 1 ng/mL E2) and calibration curve results. The stability of standard reagents, samples and sample extracts was also investigated. These data demonstrated this method to be an accurate indicator of estrogenic activity for both chemicals and extracts.
Collapse
Affiliation(s)
- Xueping Chen
- Vitargent (International) Biotechnology Limited, Unit 516, Biotech Centre 2, 11 Science Park West Avenue, Hong Kong Science Park, Hong Kong SAR, 999077, China.
| | - Shuk Han Cheng
- College of Veterinary Medicine and Life Science, City University of Hong Kong, Hong Kong SAR, 999077, China.
| | - Masato Kinoshita
- Division of Applied Bioscience, Graduate School of Agriculture, Kyoto University, Kyoto, Japan.
| | - Peter A de Witte
- Laboratory for Molecular Biodiscovery, Department of Pharmaceutical and Pharmacological Sciences, University of Leuven, O & N II Herestraat 49-Box 824, 3000, Leuven, Belgium.
| | - Jianjun Liu
- Key Laboratory of Modern Toxicology of Shenzhen, Medical Key Laboratory of Health Toxicology, Laboratory of Modern Toxicology, Shenzhen Centre for Disease Control and Prevention, Shenzhen, 518060, China.
| | - David Hinton
- Nicholas School of the Environment, Duke University, A333a LSRC, Durham, NC, 27708, United States.
| | - Thomas Braunbeck
- Aquatic Ecology and Toxicology, Center for Organismal Studies, Heidelberg University, Im Neuenheimer Feld 504, D-69120, Heidelberg, Germany.
| | - Ian Cotgreave
- RISE, Research Institutes of Sweden, Unit of Chemical and Pharmaceutical Safety, Division of Bioeconomy and Health, S-15134, Södertälje, Sweden.
| | - Daniel Schlenk
- Department of Environmental Sciences, University of California, Riverside, CA, 92521, United States.
| | - Zhiyuan Gong
- Department of Biological Sciences, National University of Singapore, Singapore.
| | - Hani El-Nezami
- School of Biological Sciences, Faculty of Science, The University of Hong Kong, Hong Kong SAR, 999077, China.
| | - Kin Chung Ho
- College of Marine Ecology and Environment, Shanghai Ocean University, China.
| | - Kwok Fai Chan
- Vitargent (International) Biotechnology Limited, Unit 516, Biotech Centre 2, 11 Science Park West Avenue, Hong Kong Science Park, Hong Kong SAR, 999077, China.
| | - Shisan Xu
- Vitargent (International) Biotechnology Limited, Unit 516, Biotech Centre 2, 11 Science Park West Avenue, Hong Kong Science Park, Hong Kong SAR, 999077, China.
| | - Pui Ying Yiu
- Vitargent (International) Biotechnology Limited, Unit 516, Biotech Centre 2, 11 Science Park West Avenue, Hong Kong Science Park, Hong Kong SAR, 999077, China.
| | - Huan Zhang
- Vitargent (International) Biotechnology Limited, Unit 516, Biotech Centre 2, 11 Science Park West Avenue, Hong Kong Science Park, Hong Kong SAR, 999077, China.
| | - Desheng Wu
- Key Laboratory of Modern Toxicology of Shenzhen, Medical Key Laboratory of Health Toxicology, Laboratory of Modern Toxicology, Shenzhen Centre for Disease Control and Prevention, Shenzhen, 518060, China.
| | - Yu Suen Chan
- College of Veterinary Medicine and Life Science, City University of Hong Kong, Hong Kong SAR, 999077, China.
| | - Annelii Ny
- Laboratory for Molecular Biodiscovery, Department of Pharmaceutical and Pharmacological Sciences, University of Leuven, O & N II Herestraat 49-Box 824, 3000, Leuven, Belgium.
| | - Jan Maes
- Laboratory for Molecular Biodiscovery, Department of Pharmaceutical and Pharmacological Sciences, University of Leuven, O & N II Herestraat 49-Box 824, 3000, Leuven, Belgium.
| |
Collapse
|
19
|
Loerracher AK, Braunbeck T. Cytochrome P450-dependent biotransformation capacities in embryonic, juvenile and adult stages of zebrafish (Danio rerio)-a state-of-the-art review. Arch Toxicol 2021; 95:2299-2334. [PMID: 34148099 PMCID: PMC8241672 DOI: 10.1007/s00204-021-03071-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2021] [Accepted: 05/04/2021] [Indexed: 01/08/2023]
Abstract
Given the strong trend to implement zebrafish (Danio rerio) embryos as translational model not only in ecotoxicological, but also toxicological testing strategies, there is an increasing need for a better understanding of their capacity for xenobiotic biotransformation. With respect to the extrapolation of toxicological data from zebrafish embryos to other life stages or even other organisms, qualitative and quantitative differences in biotransformation pathways, above all in cytochrome P450-dependent (CYP) phase I biotransformation, may lead to over- or underestimation of the hazard and risk certain xenobiotic compounds may pose to later developmental stages or other species. This review provides a comprehensive state-of-the-art overview of the scientific knowledge on the development of the CYP1-4 families and corresponding phase I biotransformation and bioactivation capacities in zebrafish. A total of 68 publications dealing with spatiotemporal CYP mRNA expression patterns, activities towards mammalian CYP-probe substrates, bioactivation and detoxification activities, as well as metabolite profiling were analyzed and included in this review. The main results allow for the following conclusions: (1) Extensive work has been done to document mRNA expression of CYP isoforms from earliest embryonic stages of zebrafish, but juvenile and adult zebrafish have been largely neglected so far. (2) There is insufficient understanding of how sex- and developmental stage-related differences in expression levels of certain CYP isoforms may impact biotransformation and bioactivation capacities in the respective sexes and in different developmental stages of zebrafish. (3) Albeit qualitatively often identical, many studies revealed quantitative differences in metabolic activities of zebrafish embryos and later developmental stages. However, the actual relevance of age-related differences on the outcome of toxicological studies still needs to be clarified. (4) With respect to current remaining gaps, there is still an urgent need for further studies systematically assessing metabolic profiles and capacities of CYP isoforms in zebrafish. Given the increasing importance of Adverse Outcome Pathway (AOP) concepts, an improved understanding of CYP capacities appears essential for the interpretation and outcome of (eco)toxicological studies.
Collapse
Affiliation(s)
- Ann-Kathrin Loerracher
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, 69120, Heidelberg, Germany.
| | - Thomas Braunbeck
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, 69120, Heidelberg, Germany.
| |
Collapse
|
20
|
Teixeira TM, Arraes IG, Abreu DC, Oliveira KM, Correa RS, Batista AA, Braunbeck T, de Paula Silveira Lacerda E. Ruthenium complexes show promise when submitted to toxicological safety tests using alternative methodologies. Eur J Med Chem 2021; 216:113262. [PMID: 33711764 DOI: 10.1016/j.ejmech.2021.113262] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 01/30/2021] [Accepted: 01/31/2021] [Indexed: 12/30/2022]
Abstract
The number of cancer cases continues to increase worldwide, and unfortunately the main systemic treatments available have numerous of side effects. Ruthenium complexes have shown to be promising chemotherapeutic agents, since they present low toxicity and are more selective for tumor tissues. We report the synthesis, characterization and biological properties of two new ruthenium (II) complexes containing Lapachol and Lawsone as ligands: (1) [Ru(Law)(dppb)(phen)]PF6 and (2) [Ru(Lap)(dppb)(phen)]PF6, where Law = Lawsone, Lap = Lapachol, dppb = 1,4-bis(diphenylphosphine)butane and phen = 1,10-phenanthroline. The ability of the complexes (1) and (2) to interact with CT-DNA (Calf Thymus) was investigated, and the results indicate that the complexes have shown a weak interaction with this macromolecule. Complexes (1) and (2) showed a moderate interaction with BSA, via a spontaneous process with the involvement of van der Waals and hydrogen bond interactions. Both complexes were tested against human lung cancer cell lines, chronic human myeloid leukemia, murine melanoma and human cervical and non-tumoral murine fibroblast adenocarcinoma, human lung fibroblasts and monkey kidney epithelia. The potential for cytotoxicity was tested out using the MTT assay and the neutral red test, to calculate inhibitory concentrations (IC50) and selectivity indices (IS). Both complexes showed a higher selectivity index of 1.17 and 10.91, respectively, for the HeLa tumor line. Studies of toxicological evaluation, using the micronucleus test and the comet assay against non-tumor cells, as well as an assessment of the potential for acute toxicity and neurotoxicity in zebrafish (Danio rerio). In the in vitro micronucleus test, complex (1) showed the least genotoxic potential, and in the in vitro comet assay both compounds had revealed a genotoxic potential at 0.5 and 1.0 mg L-1, with no difference between 24 h and 48 h exposure times. In the acute toxicity tests on zebrafish embryos, complex (1) showed sublethal effects such as decreased blood circulation and heartbeat rate, which were less pronounced than with complex (2). In contrast to complex 2, which caused lethality even before 48h, complex (1) did not cause the death of the embryos at concentrations up to (2.0 mg L-1). Complex (2) also lead to a delay in the embryo. Cell based in vitro methods thus proved able to provide specific toxicological data, allowing a significant reduction in ∖animal experimentation. Given that in vitro tests cannot completely replace animal tests, the use of less advanced developmental stages such as zebrafish embryos, which - at least in the European Union - are not regarded protected, could be shown to be an excellent alternative for testing with, e.g., mammals.
Collapse
Affiliation(s)
- Thallita Monteiro Teixeira
- Instituto de Ciências Biológicas, Universidade Federal de Goiás (UFG), CEP 74045-155, Goiânia, GO, Brazil; Aquatic Ecology and Toxicology, Center for Organismal Studies, University of Heidelberg, D-69117, Heidelberg, Germany.
| | - Isabela Gasparini Arraes
- Instituto de Ciências Biológicas, Universidade Federal de Goiás (UFG), CEP 74045-155, Goiânia, GO, Brazil
| | - Davi Carvalho Abreu
- Instituto de Ciências Biológicas, Universidade Federal de Goiás (UFG), CEP 74045-155, Goiânia, GO, Brazil
| | - Katia M Oliveira
- Departamento de Química, Universidade Federal de São Carlos (UFSCar), CP 676, CEP 13565-905, São Carlos, SP, Brazil; Departamento de Química, ICEB, Universidade Federal de Ouro Preto (UFOP), CEP 35400-000, Ouro Preto, MG, Brazil
| | - Rodrigo S Correa
- Departamento de Química, ICEB, Universidade Federal de Ouro Preto (UFOP), CEP 35400-000, Ouro Preto, MG, Brazil
| | - Alzir A Batista
- Departamento de Química, Universidade Federal de São Carlos (UFSCar), CP 676, CEP 13565-905, São Carlos, SP, Brazil
| | - Thomas Braunbeck
- Aquatic Ecology and Toxicology, Center for Organismal Studies, University of Heidelberg, D-69117, Heidelberg, Germany
| | | |
Collapse
|
21
|
Zindler F, Stoll S, Baumann L, Knoll S, Huhn C, Braunbeck T. Do environmentally relevant concentrations of fluoxetine and citalopram impair stress-related behavior in zebrafish (Danio rerio) embryos? Chemosphere 2020; 261:127753. [PMID: 32745739 DOI: 10.1016/j.chemosphere.2020.127753] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 07/14/2020] [Accepted: 07/15/2020] [Indexed: 06/11/2023]
Abstract
Selective serotonin reuptake inhibitors (SSRIs) have been shown to interfere with various physiological functions of aquatic organisms, yet the neuroactive potential of low concentrations of SSRIs in the aquatic environment is unclear. The current study investigated the effects of fluoxetine and citalopram on the visual motor response (VMR) of 107 h old zebrafish (Danio rerio) embryos. Results document a reduction in stress-related swimming activity of zebrafish embryos at environmentally relevant concentration levels, with fluoxetine being more effective than citalopram. Further experiments were designed to elucidate (1) if the lower neuroactive potential of citalopram is due to differences in uptake kinetics, (2) if the metabolite of fluoxetine, norfluoxetine, contributes to the neuroactive potential of fluoxetine, (3) and how SSRIs and their metabolites interact in equimolar mixtures. At the stage of 120 h, zebrafish embryos accumulate citalopram at significantly lower rates (up to 127 times) than fluoxetine. Moreover, it was demonstrated that norfluoxetine reduces the embryonic VMR similarly to fluoxetine resulting in additive effects of these substances on stress-related behavior in zebrafish embryos. In contrast, the interaction of fluoxetine, norfluoxetine and citalopram varied with test concentrations of the equimolar mixtures. Findings provide evidence that environmentally relevant concentrations of fluoxetine reduce stress-related behavior of zebrafish embryos, while these effects may be enhanced by the interaction of multiple SSRIs and their metabolites in environmental exposure scenarios.
Collapse
Affiliation(s)
- Florian Zindler
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, Heidelberg, D-69120, Germany.
| | - Saskia Stoll
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, Heidelberg, D-69120, Germany
| | - Lisa Baumann
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, Heidelberg, D-69120, Germany
| | - Sarah Knoll
- Institute for Physical and Theoretical Chemistry, University of Tübingen, Auf der Morgenstelle 18, Tübingen, D-72076, Germany
| | - Carolin Huhn
- Institute for Physical and Theoretical Chemistry, University of Tübingen, Auf der Morgenstelle 18, Tübingen, D-72076, Germany
| | - Thomas Braunbeck
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, Heidelberg, D-69120, Germany
| |
Collapse
|
22
|
Siméon S, Brotzmann K, Fisher C, Gardner I, Silvester S, Maclennan R, Walker P, Braunbeck T, Bois FY. Corrigendum to "Development of a generic zebrafish embryo PBPK model and application to the developmental toxicity assessment of valproic acid analogs" [Reprod. Toxicol. 93 (2020) 219⬜229]. Reprod Toxicol 2020; 98:300-303. [PMID: 33153860 DOI: 10.1016/j.reprotox.2020.10.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Affiliation(s)
- Ségolène Siméon
- INERIS, METO unit, Parc ALATA BP2, Verneuil en Halatte, France
| | - Katharina Brotzmann
- University of Heidelberg, Aquatic Ecology and Toxicology, Centre for Organismal Studies (COS), Im Neuenheimer Feld504, D-69120 Heidelberg, Germany
| | - Ciarán Fisher
- CERTARA UK Limited, Simcyp Division, Level 2-Acero, 1 Concourse Way, Sheffield, S1 2BJ, United Kingdom
| | - Iain Gardner
- CERTARA UK Limited, Simcyp Division, Level 2-Acero, 1 Concourse Way, Sheffield, S1 2BJ, United Kingdom
| | - Steve Silvester
- Cyprotex Discovery Ltd., No. 24 Mereside, Alderley Park, Macclesfield, Cheshire, SK10 4TG, United Kingdom
| | - Richard Maclennan
- Cyprotex Discovery Ltd., No. 24 Mereside, Alderley Park, Macclesfield, Cheshire, SK10 4TG, United Kingdom
| | - Paul Walker
- Cyprotex Discovery Ltd., No. 24 Mereside, Alderley Park, Macclesfield, Cheshire, SK10 4TG, United Kingdom
| | - Thomas Braunbeck
- University of Heidelberg, Aquatic Ecology and Toxicology, Centre for Organismal Studies (COS), Im Neuenheimer Feld504, D-69120 Heidelberg, Germany
| | - Frederic Y Bois
- CERTARA UK Limited, Simcyp Division, Level 2-Acero, 1 Concourse Way, Sheffield, S1 2BJ, United Kingdom.
| |
Collapse
|
23
|
Hanslik L, Sommer C, Huppertsberg S, Dittmar S, Knepper TP, Braunbeck T. Microplastic-associated trophic transfer of benzo(k)fluoranthene in a limnic food web: Effects in two freshwater invertebrates (Daphnia magna, Chironomus riparius) and zebrafish (Danio rerio). Comp Biochem Physiol C Toxicol Pharmacol 2020; 237:108849. [PMID: 32768657 DOI: 10.1016/j.cbpc.2020.108849] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Revised: 06/25/2020] [Accepted: 07/10/2020] [Indexed: 12/22/2022]
Abstract
The continuously growing plastic production and incomplete recycling processes open manifold entry routes for microplastic particles (MPs) into the environment. Since knowledge on trophic transfer of contaminants sorbed to MPs is still insufficient for freshwater systems, the transfer of the model pollutant benzo(k)fluoranthene (BkF) sorbed to polymethyl methacrylate (PMMA) particles in a limnic food web was investigated: Two freshwater invertebrates (Daphnia magna and Chironomus riparius larvae) were selected and either left untreated, exposed to pristine PMMA, PMMA-associated BkF, or exposed to dissolved BkF (BkFaq). As second-level consumers, zebrafish (Danio rerio) were fed twice daily with pre-treated invertebrates over two days. Induction of hepatic cytochrome P450 by BkF was determined as 7-ethoxy-O-resorufin deethylase (EROD) activity. Both invertebrate species readily ingested PMMA particles, tracked via fluorescence microscopy and accumulated BkFaq, measured via GC-MS. Fluorescence signals in gastrointestinal tracts of zebrafish were quantified with confocal laser scanning microscopy (CLSM). The fluorescence signal in gastrointestinal tracts of zebrafish was not altered, whereas, EROD activity was significantly induced when zebrafish were fed with Chironomus riparius, pre-exposed to BkFaq. Trophic exposure scenarios with BkF sorbed to PMMA did not result in any alterations of investigated endpoints in both invertebrate species and zebrafish compared to controls. Given that BkF amounts were in the low ng-range, as detected by GC-MS, the transport of MP-sorbed BkF to zebrafish was less effective than direct exposure to waterborne BkFaq, and the potential threat of trophic transfer of substances such as BkF in limnic food webs may have been overestimated.
Collapse
Affiliation(s)
- Lisa Hanslik
- Aquatic Ecology and Toxicology Group, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, D-69120 Heidelberg, Germany.
| | - Carmen Sommer
- Aquatic Ecology and Toxicology Group, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, D-69120 Heidelberg, Germany
| | - Sven Huppertsberg
- Hochschule Fresenius GmbH, University of Applied Sciences Fresenius, Limburger Str. 2, D-65510 Idstein, Germany
| | - Stefan Dittmar
- Chair of Water Quality Control, Technical University of Berlin, Str. des 17. Juni 135, D-10623 Berlin, Germany
| | - Thomas P Knepper
- Hochschule Fresenius GmbH, University of Applied Sciences Fresenius, Limburger Str. 2, D-65510 Idstein, Germany
| | - Thomas Braunbeck
- Aquatic Ecology and Toxicology Group, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, D-69120 Heidelberg, Germany.
| |
Collapse
|
24
|
Brotzmann K, Wolterbeek A, Kroese D, Braunbeck T. Neurotoxic effects in zebrafish embryos by valproic acid and nine of its analogues: the fish-mouse connection? Arch Toxicol 2020; 95:641-657. [PMID: 33111190 PMCID: PMC7870776 DOI: 10.1007/s00204-020-02928-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Accepted: 10/05/2020] [Indexed: 01/26/2023]
Abstract
Since teratogenicity testing in mammals is a particular challenge from an animal welfare perspective, there is a great need for the development of alternative test systems. In this context, the zebrafish (Danio rerio) embryo has received increasing attention as a non-protected embryonic vertebrate in vivo model. The predictive power of zebrafish embryos for general vertebrate teratogenicity strongly depends on the correlation between fish and mammals with respect to both overall general toxicity and more specific endpoints indicative of certain modes-of-action. The present study was designed to analyze the correlation between (1) effects of valproic acid and nine of its analogues in zebrafish embryos and (2) their known neurodevelopmental effects in mice. To this end, zebrafish embryos exposed for 120 h in an extended version of the acute fish embryo toxicity test (FET; OECD TG 236) were analyzed with respect to an extended list of sublethal endpoints. Particular care was given to endpoints putatively related to neurodevelopmental toxicity, namely jitter/tremor, deformation of sensory organs (eyes) and craniofacial deformation, which might correlate to neural tube defects caused by valproic acid in mammals. A standard evaluation of lethal (LC according to OECD TG 236) and sublethal toxicity (EC) merely indicated that four out of ten compounds tested in zebrafish correlate with positive results in mouse in vivo studies. A detailed assessment of more specific effects, however, namely, jitter/tremor, small eyes and craniofacial deformation, resulted in a correspondence of 75% with in vivo mouse data. A refinement of endpoint analysis from an integration of all observations into one LCx or ECx data (as foreseen by current ecotoxicology-driven OECD guidelines) to a differential evaluation of endpoints specific of selected modes-of-action thus increases significantly the predictive power of the zebrafish embryo model for mammalian teratogenicity. However, for some of the endpoints observed, e.g., scoliosis, lordosis, pectoral fin deformation and lack of movement, further experiments are required for the identification of underlying modes-of-action and an unambiguous interpretation of their predictive power for mammalian toxicity.
Collapse
Affiliation(s)
- Katharina Brotzmann
- Aquatic Ecology and Toxicology Group, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, 69120, Heidelberg, Germany.
| | - André Wolterbeek
- TNO Healthy Living Unit, Department of Risk Analysis for Products in Development, The Netherlands Organization for Applied Scientific Research, Princetonlaan 6, 3584 CB, Utrecht, The Netherlands
| | - Dinant Kroese
- TNO Healthy Living Unit, Department of Risk Analysis for Products in Development, The Netherlands Organization for Applied Scientific Research, Princetonlaan 6, 3584 CB, Utrecht, The Netherlands
| | - Thomas Braunbeck
- Aquatic Ecology and Toxicology Group, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, 69120, Heidelberg, Germany.
| |
Collapse
|
25
|
Cousin X, Batel A, Bringer A, Hess S, Bégout ML, Braunbeck T. Microplastics and sorbed contaminants - Trophic exposure in fish sensitive early life stages. Mar Environ Res 2020; 161:105126. [PMID: 32891915 DOI: 10.1016/j.marenvres.2020.105126] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2020] [Revised: 08/17/2020] [Accepted: 08/21/2020] [Indexed: 06/11/2023]
Abstract
The present study evaluated very small microplastic particle (MPs) transfer to zebrafish and marine medaka larvae via prey experimentally exposed to MPs from the onset of feeding. Larvae were fed Paramecium or Artemia nauplii loaded with fluorescent 1-5 or 10-20 μm MP. Pollutant accumulation was analyzed by optically tracking of benzo[a]pyrene (BaP) and recording cyp1a transcription. Paramecium transferred 1-5 μm particles only, whereas Artemia efficiently transferred both MPs. Although zebrafish and medaka larvae fed from the onset of active food intake (2-3 dph, respectively) on Paramecium and from days 6-7 post-hatch on Artemia nauplii, neither MP accumulation nor translocation to tissues was detected. MP egestion started within few hours after ingestion. Cyp1a induction and fluorescent analyses proved BaP bioavailability after transfer via Paramecium and Artemia. Unicellular or plankton organisms ingest contaminants via MPS and transfer effectively these to sensitive early life-stages of vertebrates, giving rise to whole-life exposure.
Collapse
Affiliation(s)
- Xavier Cousin
- Laboratoire Ressources Halieutiques, IFREMER, Place Gaby Coll, L'Houmeau, France; MARBEC, Univ. Montpellier, CNRS, IFREMER, IRD Palavas-les-Flots, France; Univ. Paris-Saclay, AgroParisTech, INRAE, GABI, Jouy-en-Josas, France.
| | - Annika Batel
- Aquatic Ecology and Toxicology, Centre for Organismal Studies, University of Heidelberg, Heidelberg, Germany
| | - Arno Bringer
- Laboratoire Ressources Halieutiques, IFREMER, Place Gaby Coll, L'Houmeau, France
| | - Sebastian Hess
- Aquatic Ecology and Toxicology, Centre for Organismal Studies, University of Heidelberg, Heidelberg, Germany
| | - Marie-Laure Bégout
- Laboratoire Ressources Halieutiques, IFREMER, Place Gaby Coll, L'Houmeau, France; MARBEC, Univ. Montpellier, CNRS, IFREMER, IRD Palavas-les-Flots, France
| | - Thomas Braunbeck
- Aquatic Ecology and Toxicology, Centre for Organismal Studies, University of Heidelberg, Heidelberg, Germany
| |
Collapse
|
26
|
Paparella M, Scholz S, Belanger S, Braunbeck T, Bicherel P, Connors K, Faßbender C, Halder M, Lillicrap A, Liska R, Schirmer K, Stoddart G, Thomas P, Walter-Rohde S. Limitations and uncertainties of acute fish toxicity assessments can be reduced using alternative methods. ALTEX 2020; 38:20-32. [PMID: 32970822 DOI: 10.14573/altex.2006051] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Accepted: 09/16/2020] [Indexed: 11/23/2022]
Abstract
Information about acute fish toxicity is routinely required in many jurisdictions for environmental risk assessment of chemicals. This information is typically obtained using a 96-hour juvenile fish test for lethality according to OECD test guideline (TG) 203 or equivalent regional guidelines. However, TG 203 has never been validated using the criteria currently required for new test methods including alternative methods. Characterization of the practicality and validity of TG 203 is important to provide a benchmark for alternative methods. This contribution systematically summarizes the available knowledge on limitations and uncertainties of TG 203, based on methodological, statistical, and biological considerations. Uncertainties stem from the historic flexibility (e.g., use of a broad range of species) and constraints of the basic test design (e.g., no replication). Other sources of uncertainty arise from environmental safety extrapolation based on TG 203 data. Environmental extrapolation models, combined with data from alternative methods, including mechanistic indicators of toxicity, may provide at least the same level of environmental protection. Yet, most importantly, the 3R advantages of alternative methods allow a better standardization, characterization, and an improved basic study design. This can enhance data reliability and thus facilitate the comparison of chemical toxicity, as well as the environmental classifications and prediction of no-effect concentrations of chemicals. Combined with the 3R gains and the potential for higher throughput, a reliable assessment of more chemicals can be achieved, leading to improved environmental protection.
Collapse
Affiliation(s)
- Martin Paparella
- Division of Medical Biochemistry, Medical University Innsbruck, Innsbruck, Austria
| | - Stefan Scholz
- UFZ - Helmholtz Centre for Environmental Research, Department of Bioanalytical Ecotoxicology, Leipzig, Germany
| | | | - Thomas Braunbeck
- Aquatic Ecology & Toxicology, University of Heidelberg, INF 504, Heidelberg, Germany
| | - Pascal Bicherel
- Knowledge & Research in Environment and Toxicology in Silico (KREATiS), L'Isle d'Abeau, France
| | | | | | - Marlies Halder
- European Commission, Joint Research Centre, Ispra, Italy
| | - Adam Lillicrap
- Norwegian Institute for Water Research (NIVA), Oslo, Norway
| | - Roman Liska
- European Commission, Joint Research Centre, Ispra, Italy
| | - Kristin Schirmer
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, Dübendorf, Switzerland.,EPF Lausanne, School of Architecture, Civil and Environmental Engineering, Lausanne, Switzerland.,ETH Zürich, Department of Environmental Systems Science, Zürich, Switzerland
| | - Gilly Stoddart
- PETA International Science Consortium Ltd., London, United Kingdom
| | - Paul Thomas
- Knowledge & Research in Environment and Toxicology in Silico (KREATiS), L'Isle d'Abeau, France
| | | |
Collapse
|
27
|
Pauler CM, Isselstein J, Berard J, Braunbeck T, Schneider MK. Grazing Allometry: Anatomy, Movement, and Foraging Behavior of Three Cattle Breeds of Different Productivity. Front Vet Sci 2020; 7:494. [PMID: 32923468 PMCID: PMC7457131 DOI: 10.3389/fvets.2020.00494] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Accepted: 06/30/2020] [Indexed: 12/03/2022] Open
Abstract
Modern breeding has formed a multitude of cattle breeds ranging from undemanding, low-productive breeds to high-productive, specialized dairy, or beef cattle. The choice of breed has important implications for farm management, but its impact on pasture vegetation is underestimated. We hypothesized (i) that anatomy, movement, and foraging behavior of cattle are allometrically related on the individual level, (ii) that differences among cattle are not explained by individual variation alone but also by breed, and (iii) that anatomy, movement, and foraging behavior of a cattle breed is related to its productivity. In order to test these hypotheses, we conducted a controlled grazing experiment in which three cattle breeds simultaneously grazed three types of heterogenous, alpine pastures: low-productive Highland cattle (average weight: 358 kg); local, dual-purpose Original Braunvieh (582 kg); and high-productive Angus × Holstein crossbreed (679 kg). We measured body weight and claw base of nine cows per breed after 10 weeks of grazing alpine pastures. Over a period of 9 days, we recorded the step frequency and lying time by pedometer and space use by GPS. Moreover, we visually observed foraging behavior on three occasions per cow. Forage selectivity and quality were calculated for every cow's diet. Allometric relationships were analyzed on the individual level by fitting standardized major axes. For most parameters measured, we detected strong allometric relationships and clear differences among breeds that depended on the level of productivity. The claws of Highland cattle were relatively large compared to their body weight and thus they exerted less static pressure than other breeds. Moreover, the more productive a breed was, the higher its selectivity and step frequency were. For example, Highland cattle foraged shrubs and thistles more frequently than high-productive Angus × Holstein. The latter walked longer distances to select higher-quality forage, while Highland cattle used the space more evenly, visited steeper slopes, and moved further away from water points. Irrespective of breed, vegetation composition influenced cattle behavior: On pastures of low forage quality, animals walked more, foraged more selectively, and used space less evenly. In conclusion, the observed breed-specific differences can be used to improve pasture management and grassland conservation.
Collapse
Affiliation(s)
- Caren M Pauler
- Forage Production and Grassland Systems, Agroscope, Zurich, Switzerland.,Department of Crop Sciences, Georg-August-University, Göttingen, Germany.,Centre for Organismal Studies, Ruprecht-Karls-University, Heidelberg, Germany
| | | | - Joel Berard
- AgroVet-Strickhof, Lindau, Switzerland.,Animal Production Systems and Animal Health, Agroscope, Zurich, Switzerland
| | - Thomas Braunbeck
- Centre for Organismal Studies, Ruprecht-Karls-University, Heidelberg, Germany
| | | |
Collapse
|
28
|
Loerracher AK, Braunbeck T. Inducibility of cytochrome P450-mediated 7-methoxycoumarin-O-demethylase activity in zebrafish (Danio rerio) embryos. Aquat Toxicol 2020; 225:105540. [PMID: 32569997 DOI: 10.1016/j.aquatox.2020.105540] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 05/31/2020] [Accepted: 06/07/2020] [Indexed: 06/11/2023]
Abstract
The zebrafish (Danio rerio) embryo has increasingly been used as an alternative model in human and environmental toxicology. Since the cytochrome P450 (CYP) system is of fundamental importance for the understanding and correct interpretation of the outcome of toxicological studies, constitutive and xenobiotic-induced 7-methoxycoumarin-O-demethylase (MCOD), i.e. 'mammalian CYP2-like', activities were monitored in vivo in zebrafish embryos via confocal laser scanning microscopy. In order to elucidate molecular mechanisms underlying the MCOD induction, dose-dependent effects of the prototypical CYP inducers β-naphthoflavone (aryl hydrocarbon receptor (AhR) agonist), rifampicin (pregnane X receptor (PXR) agonist), carbamazepine and phenobarbital (constitutive androstane receptor (CAR) agonists) were analyzed in zebrafish embryos of varying age. Starting from 36 h of age, all embryonic stages of zebrafish could be shown to have constitutive MCOD activity, albeit with spatial variation and at distinct levels. Whereas carbamazepine, phenobarbital and rifampicin had no effect on in vivo MCOD activity in 96 h old zebrafish embryos, the model aryl hydrocarbon receptor agonist β-naphthoflavone significantly induced MCOD activity in 96 h old zebrafish embryos at 46-734 nM, however, without a clear concentration-effect relationship. Induction of MCOD activity by β-naphthoflavone gradually decreased with progression of embryonic development. By in vivo characterization of constitutive and xenobiotic-induced MCOD activity patterns in 36, 60, 84 and 108 h old zebrafish embryos, this decrease could primarily be attributed to an age-related decline in the induction of MCOD activity in the cardiovascular system. Results of this study provide novel insights into the mechanism and extent, by which specific CYP activities in early life-stages of zebrafish can be influenced by exposure to xenobiotics. The study thus lends further support to the view that zebrafish embryos- at least from an age of 36 h - have an elaborate and inducible biotransformation system.
Collapse
Affiliation(s)
- Ann-Kathrin Loerracher
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, D-69120, Heidelberg, Germany.
| | - Thomas Braunbeck
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, D-69120, Heidelberg, Germany
| |
Collapse
|
29
|
Knoll S, Jacob S, Mieck S, Triebskorn R, Braunbeck T, Huhn C. Development of a capillary electrophoresis-mass spectrometry method for the analysis of metformin and its transformation product guanylurea in biota. Anal Bioanal Chem 2020; 412:4985-4996. [PMID: 32572543 PMCID: PMC7334255 DOI: 10.1007/s00216-020-02759-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Revised: 04/30/2020] [Accepted: 06/05/2020] [Indexed: 12/13/2022]
Abstract
A method with capillary electrophoresis coupled to mass spectrometry was optimized to determine the uptake of metformin and its metabolite guanylurea by zebrafish (Danio rerio) embryos and brown trout (Salmo trutta f. fario) exposed under laboratory conditions. Metformin was extracted from fish tissues by sonication in methanol, resulting in an absolute recovery of almost 90%. For the extraction of guanylurea from brown trout, solid-phase extraction was implemented with a recovery of 84%. The use of a mixture of methanol and glacial acetic acid as a non-aqueous background electrolyte was vital to achieve robust analysis using a bare fused-silica capillary with an applied voltage of +30 kV. Problems with adsorption associated with an aqueous background electrolyte were eliminated using a non-aqueous background electrolyte made of methanol/acetic acid (97:3) with 25 mM ammonium acetate (for zebrafish embryos) or 100 mM ammonium acetate (for brown trouts), depending on the sample complexity and matrix influences. High resolution and high separation selectivity from matrix components were achieved by optimization of the ammonium acetate concentration in the background electrolyte. An extensive evaluation of matrix effects was conducted with regard to the complex matrices present in the fish samples. They required adapting the background electrolyte to higher concentrations. Applying this method to extracts of zebrafish embryos and brown trout tissue samples, limits of detection for both metformin and guanylurea in zebrafish embryos (12.2 μg/l and 15 μg/l) and brown trout tissues (15 ng/g and 34 ng/g) were in the low μg/l or ng/g range. Finally, metformin and guanylurea could be both quantified for the first time in biota samples from exposure experiments.
Collapse
Affiliation(s)
- Sarah Knoll
- Institute of Physical and Theoretical Chemistry, University of Tübingen, Auf der Morgenstelle 18, Tübingen, Germany
| | - Stefanie Jacob
- Animal Physiological Ecology Group, Institute of Evolution and Ecology, University of Tübingen, Auf der Morgenstelle 5, Tübingen, Germany
| | - Susanna Mieck
- Aquatic Ecology and Toxicology Group, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, Heidelberg, Germany
| | - Rita Triebskorn
- Animal Physiological Ecology Group, Institute of Evolution and Ecology, University of Tübingen, Auf der Morgenstelle 5, Tübingen, Germany
| | - Thomas Braunbeck
- Aquatic Ecology and Toxicology Group, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, Heidelberg, Germany
| | - Carolin Huhn
- Institute of Physical and Theoretical Chemistry, University of Tübingen, Auf der Morgenstelle 18, Tübingen, Germany.
| |
Collapse
|
30
|
Heinrich P, Hanslik L, Kämmer N, Braunbeck T. The tox is in the detail: technical fundamentals for designing, performing, and interpreting experiments on toxicity of microplastics and associated substances. Environ Sci Pollut Res Int 2020; 27:22292-22318. [PMID: 32335837 DOI: 10.1007/s11356-020-08859-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Accepted: 04/13/2020] [Indexed: 06/11/2023]
Abstract
Over the last 10 years, there has been a plethora of experimental studies estimating the potential of microplastic particles (MPs) to exert toxic effects in the environment, many specifically focusing on their postulated capacity to enhance the transfer of environmental pollutants into organisms after ingestion. Obviously, there is little to no consensus on appropriate experimental design, which is mainly owing to the novelty, the interdisciplinarity of the subject, and the complexity of parameters involved. This results in fundamental discrepancies regarding the materials applied, the approach for spiking MPs with pollutants, and the exact exposure scenario. Aiming for a non-chemist audience and providing illustrative, representative, and comparative examples, this review first outlines the theoretical essentials of processes involved in sorption. Also, it discusses the implications for designing experimental approaches using MPs and interpreting the results obtained under consideration of their relevance for environmental conditions. It may help to improve the interpretation of studies on MP toxicity already published, while also calling experimenters' attention to various aspects important to consider when designing and performing environmentally relevant experiments with MPs.
Collapse
Affiliation(s)
- Patrick Heinrich
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, 69120, Heidelberg, Germany.
| | - Lisa Hanslik
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, 69120, Heidelberg, Germany
| | - Nadine Kämmer
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, 69120, Heidelberg, Germany
| | - Thomas Braunbeck
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, 69120, Heidelberg, Germany
| |
Collapse
|
31
|
Zindler F, Tisler S, Loerracher AK, Zwiener C, Braunbeck T. Norfluoxetine Is the Only Metabolite of Fluoxetine in Zebrafish ( Danio rerio) Embryos That Accumulates at Environmentally Relevant Exposure Scenarios. Environ Sci Technol 2020; 54:4200-4209. [PMID: 32167300 DOI: 10.1021/acs.est.9b07618] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Fluoxetine has been recognized as one of the most toxic pharmaceuticals in the aquatic environment. Since there is growing evidence that the toxic potential of fluoxetine in surface waters is markedly influenced by its own metabolism in aquatic species, this study investigated the biotransformation of fluoxetine in the zebrafish embryo - an aquatic model organism of intermediate complexity. Zebrafish embryos were exposed to 0.1, 1.0, 10, 50, and 5000 μg/L of fluoxetine from 48 to 120 h post-fertilization (hpf), and the accumulation of fluoxetine and its metabolites was analyzed over time. Additionally, depuration of fluoxetine and its metabolites from 96 to 120 hpf was investigated, and autoinhibitory effects of fluoxetine on phase I biotransformation were analyzed. Exposure to 5000 μg/L fluoxetine resulted in elevated 7-ethoxyresorufin-O-deethylase (EROD) activity of cytochrome P450 enzymes and continuous accumulation of fluoxetine and 11 fluoxetine metabolites. Embryos exposed to 10 and 50 μg/L fluoxetine were able to reduce fluoxetine accumulation from 94 to 120 hpf. During depuration, accumulation of fluoxetine and most metabolites was clearly reduced, and biotransformation shifted in favor of norfluoxetine, the primary fluoxetine metabolite in humans. Findings demonstrated that norfluoxetine is the only metabolite of fluoxetine that accumulates in zebrafish embryos at environmentally relevant exposure scenarios.
Collapse
Affiliation(s)
- Florian Zindler
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, Heidelberg D-69120, Germany
| | - Selina Tisler
- Environmental Analytical Chemistry, Center for Applied Geosciences, Eberhard Universität Tübingen, Tübingen 72074, Germany
| | - Ann-Kathrin Loerracher
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, Heidelberg D-69120, Germany
| | - Christian Zwiener
- Environmental Analytical Chemistry, Center for Applied Geosciences, Eberhard Universität Tübingen, Tübingen 72074, Germany
| | - Thomas Braunbeck
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, Heidelberg D-69120, Germany
| |
Collapse
|
32
|
Batel A, Baumann L, Carteny CC, Cormier B, Keiter SH, Braunbeck T. Histological, enzymatic and chemical analyses of the potential effects of differently sized microplastic particles upon long-term ingestion in zebrafish (Danio rerio). Mar Pollut Bull 2020; 153:111022. [PMID: 32275568 DOI: 10.1016/j.marpolbul.2020.111022] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2020] [Revised: 02/23/2020] [Accepted: 02/23/2020] [Indexed: 06/11/2023]
Abstract
In microplastics (MPs) research, there is an urgent need to critically reconsider methodological approaches and results published, since public opinion and political decisions might be based on studies using debatable methods and reporting questionable results. For instance, recent studies claim that MPs induce intestinal damage and that relatively large MPs are transferred to, e.g., livers in fish. However, there is methodological criticism and considerable concern whether MP transfer to surrounding tissues is plausible. Likewise, there is an ongoing discussion in MP research if MPs act as vectors for adsorbed hazardous chemicals. In this study, effects of very small (4-6 μm) and very large (125-500 μm) benzo(a) pyrene (BaP)-spiked polyethylene (PE) particles administered via different uptake routes (food chain vs. direct uptake) were compared in a 21-day zebrafish (Danio rerio) feeding experiment. Particular care was taken to prevent cross-contamination of MPs during dissection and histological sample preparation. In contrast to numerous reports in literature describing similar approaches, independent of exposure route and MP size, no adverse effects could be detected. Likewise, no BaP accumulation could be documented, and MPs were exclusively seen in the lumen of the intestinal tract, which, however, did not induce any histopathological effects. Results indicate that in fish MPs are taken up, pass along the intestinal lumen and are excreted without any symptoms of adverse effects.
Collapse
Affiliation(s)
- Annika Batel
- University of Heidelberg, Aquatic Ecology and Toxicology, Center for Organismal Studies, Im Neuenheimer Feld 504, D-69120 Heidelberg, Germany.
| | - Lisa Baumann
- University of Heidelberg, Aquatic Ecology and Toxicology, Center for Organismal Studies, Im Neuenheimer Feld 504, D-69120 Heidelberg, Germany
| | - Camilla Catarci Carteny
- Systemic Physiological and Ecotoxicologal Research (SPHERE), Department of Biology, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp, Belgium
| | - Bettie Cormier
- Man-Technology-Environment Research Centre, School of Science and Technology, University of Örebro, Fakultetsgatan 1, S-70182 Örebro, Sweden; Univ. Bordeaux, EPOC UMR CNRS 5805, Allée Geoffroy Saint-Hilaire, F-33615 Pessac Cedex, France
| | - Steffen H Keiter
- Man-Technology-Environment Research Centre, School of Science and Technology, University of Örebro, Fakultetsgatan 1, S-70182 Örebro, Sweden
| | - Thomas Braunbeck
- University of Heidelberg, Aquatic Ecology and Toxicology, Center for Organismal Studies, Im Neuenheimer Feld 504, D-69120 Heidelberg, Germany
| |
Collapse
|
33
|
Loerracher AK, Grethlein M, Braunbeck T. In vivo fluorescence-based characterization of cytochrome P450 activity during embryonic development of zebrafish (Danio rerio). Ecotoxicol Environ Saf 2020; 192:110330. [PMID: 32078841 DOI: 10.1016/j.ecoenv.2020.110330] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Revised: 02/03/2020] [Accepted: 02/12/2020] [Indexed: 06/10/2023]
Abstract
Zebrafish (Danio rerio) early life-stages are increasingly gaining attention as an alternative model in both human and environmental toxicology. Whereas there is amble knowledge about the transcription of various cytochrome P450 isoforms, the level of information about functional implications is still limited. This study investigated the development of CYP2-dependent 7-methoxycoumarin-O-demethylase (MCOD) activity throughout the early zebrafish development from 5 to 118 h post-fertilization (hpf) via confocal laser scanning microscopy. Results demonstrate that zebrafish embryos exhibit constitutive MCOD activity from as early as 5.5 hpf. Characteristic spatiotemporal patterns were documented with MCOD activities localized in several tissues and organs, namely the cardiovascular system, the brain, the digestive system, and the urinary tract. The study thereby contributes to a better understanding of the development and functional role of CYP enzymes in zebrafish early life-stages.
Collapse
Affiliation(s)
- Ann-Kathrin Loerracher
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, Heidelberg, D-69120, Germany.
| | - Martin Grethlein
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, Heidelberg, D-69120, Germany
| | - Thomas Braunbeck
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, Heidelberg, D-69120, Germany
| |
Collapse
|
34
|
Siméon S, Brotzmann K, Fisher C, Gardner I, Silvester S, Maclennan R, Walker P, Braunbeck T, Bois FY. Development of a generic zebrafish embryo PBPK model and application to the developmental toxicity assessment of valproic acid analogs. Reprod Toxicol 2020; 93:219-229. [PMID: 32114065 DOI: 10.1016/j.reprotox.2020.02.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Revised: 02/10/2020] [Accepted: 02/21/2020] [Indexed: 11/26/2022]
Abstract
In order to better explain, predict, or extrapolate to humans the developmental toxicity effects of chemicals to zebrafish (Danio rerio) embryos, we developed a physiologically-based pharmacokinetic (PBPK) model designed to predict organ concentrations of neutral or ionizable chemicals, up to 120 h post-fertilization. Chemicals' distribution is modeled in the cells, lysosomes, and mitochondria of ten organs of the embryo. The model's partition coefficients are calculated with sub-models using physicochemical properties of the chemicals of interest. The model accounts for organ growth and changes in metabolic clearance with time. We compared ab initio model predictions to data obtained on culture medium and embryo concentrations of valproic acid (VPA) and nine analogs during continuous dosing under the OECD test guideline 236. We further improved the predictions by estimating metabolic clearance and partition coefficients from the data by Bayesian calibration. We also assessed the performance of the model at reproducing data published by Brox et al. (2016) on VPA and 16 other chemicals. We finally compared dose-response relationships calculated for mortality and malformations on the basis of predicted whole embryo concentrations versus those based on nominal water concentrations. The use of target organ concentrations substantially shifted the magnitude of dose-response parameters and the relative toxicity ranking of chemicals studied.
Collapse
Affiliation(s)
- Ségolène Siméon
- INERIS, METO Unit, Parc ALATA BP2, Verneuil en Halatte, France
| | - Katharina Brotzmann
- University of Heidelberg, Aquatic Ecology and Toxicology, Centre for Organismal Studies (COS), Im Neuenheimer Feld 504, D-69120 Heidelberg, Germany
| | - Ciaran Fisher
- CERTARA UK Limited, Simcyp Division, Level 2-Acero, 1 Concourse Way, Sheffield, S1 2BJ, United Kingdom
| | - Iain Gardner
- CERTARA UK Limited, Simcyp Division, Level 2-Acero, 1 Concourse Way, Sheffield, S1 2BJ, United Kingdom
| | - Steve Silvester
- Cyprotex Discovery Ltd., No. 24 Mereside, Alderley Park, Macclesfield, Cheshire, SK10 4TG, United Kingdom
| | - Richard Maclennan
- Cyprotex Discovery Ltd., No. 24 Mereside, Alderley Park, Macclesfield, Cheshire, SK10 4TG, United Kingdom
| | - Paul Walker
- Cyprotex Discovery Ltd., No. 24 Mereside, Alderley Park, Macclesfield, Cheshire, SK10 4TG, United Kingdom
| | - Thomas Braunbeck
- University of Heidelberg, Aquatic Ecology and Toxicology, Centre for Organismal Studies (COS), Im Neuenheimer Feld 504, D-69120 Heidelberg, Germany
| | - Frederic Y Bois
- CERTARA UK Limited, Simcyp Division, Level 2-Acero, 1 Concourse Way, Sheffield, S1 2BJ, United Kingdom.
| |
Collapse
|
35
|
Pauler CM, Isselstein J, Suter M, Berard J, Braunbeck T, Schneider MK. Choosy grazers: Influence of plant traits on forage selection by three cattle breeds. Funct Ecol 2020. [DOI: 10.1111/1365-2435.13542] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Caren M. Pauler
- Forage Production and Grassland SystemsAgroscope Zurich Switzerland
- Department of Crop Sciences Georg‐August‐University Goettingen Germany
- Centre for Organismal Studies Ruprecht‐Karls‐University Heidelberg Germany
| | | | - Matthias Suter
- Forage Production and Grassland SystemsAgroscope Zurich Switzerland
| | | | - Thomas Braunbeck
- Centre for Organismal Studies Ruprecht‐Karls‐University Heidelberg Germany
| | | |
Collapse
|
36
|
Heinrich P, Braunbeck T. Microplastic particles reduce EROD-induction specifically by highly lipophilic compounds in RTL-W1 cells. Ecotoxicol Environ Saf 2020; 189:110041. [PMID: 31816496 DOI: 10.1016/j.ecoenv.2019.110041] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 11/29/2019] [Accepted: 11/30/2019] [Indexed: 06/10/2023]
Abstract
Microplastic particles (MPs) from lipophilic polymers have been shown to efficiently accumulate hydrophobic organic contaminants (HOCs) in aquatic environments. MPs have, therefore, frequently been discussed as vectors for contaminants, enhancing HOC uptake by various organisms after ingestion followed by pollutant release; however, integrative models of sorption argue against this mechanism and even predict cleansing of pollutants from biological systems under particular circumstances. In order to experimentally investigate such a depuration mechanism, RTL-W1 cells were dosed with three 7-ethoxyresorufin-O-deethylase (EROD) inducers of distinct lipophilicity via the medium before adding both native and hexane-purified polyethylene MPs (20-25 μm) to the medium surface. EROD activity was significantly reduced in the presence of MP, the extent of which correlated with the inducers' lipophilicity (KOW) and thus affinity to MP. For hexane-purged MPs and TCDD (KOW = 6.8), MPs reduce the bioavailability by up to 79%; the effect was marginally weaker with benzo[k]fluoranthene (KOW = 6.11) and almost absent with β-Naphthoflavone (KOW = 4.68). Compared to hexane-purged MPs, native particles possessed slightly less detoxification potential. These experimental results corroborate theoretically predicted mechanisms of detoxification via MPs. Yet, it is unclear if, under corresponding conditions in the environment, MPs can compete with organismal tissues for highly lipophilic compounds and, if so, to which degree they may act as a sink reducing the amount of bioavailable pollutants in situ. However, the present results suggest that in scenarios where pollutant-free MPs interact with organisms that accumulated HOCs via other routes of uptake, qualitatively the presence of such a mechanism is likely.
Collapse
Affiliation(s)
- Patrick Heinrich
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, D-69120, Heidelberg, Germany.
| | - Thomas Braunbeck
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, D-69120, Heidelberg, Germany
| |
Collapse
|
37
|
Baumann L, Holbech H, Schmidt-Posthaus H, Moissl AP, Hennies M, Tiedemann J, Weltje L, Segner H, Braunbeck T. Does hepatotoxicity interfere with endocrine activity in zebrafish (Danio rerio)? Chemosphere 2020; 238:124589. [PMID: 31437630 DOI: 10.1016/j.chemosphere.2019.124589] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 08/07/2019] [Accepted: 08/13/2019] [Indexed: 06/10/2023]
Abstract
Vitellogenin (VTG), a well-established biomarker for the diagnosis of endocrine activity in fish, is used in multiple OECD test guidelines (TG) to identify activities of chemicals on hormonal pathways. However, the synthesis of VTG may not only be modified by typical endocrine-related pathways, but also through non-endocrine-mediated processes. In particular, hepatotoxicity, i.e. toxicant-induced impairment of liver structure and function, might influence VTG as a biomarker, since VTG is synthesized in hepatocytes. An intimate understanding of the interplay between endocrine-related and non-endocrine-related pathways influencing VTG production is crucial for the avoidance of erroneous diagnoses in hazard assessment for regulatory purposes of chemical compounds. In order to investigate whether hepatotoxicity may interfere with hepatic VTG synthesis, adult zebrafish (Danio rerio) were exposed to three well-known hepatotoxicants, acetaminophen, isoniazid and acetylsalicylic acid, according to OECD TG 230. Various hepatotoxicity- and endocrine system-related endpoints were recorded: mRNA expression of selected endocrine- and hepatotoxicity-related marker genes in the liver; VTG levels in head/tail homogenates; and liver histopathology. All three test compounds induced significant, but mild single cell necrosis of hepatocytes and transcriptional changes of hepatotoxicity-related marker genes, thus confirming hepatotoxic effects. A positive correlation between hepatotoxicity and reduced hepatic VTG synthesis was not observed, with the single exception of a weak increase in female zebrafish exposed to APAP. This suggests that - in studies conducted according to OECD TG 229 or 230 - it is unlikely that hepatotoxic chemicals will interfere with the hepatic capacity for VTG synthesis.
Collapse
Affiliation(s)
- Lisa Baumann
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, D-69120, Heidelberg, Germany.
| | - Henrik Holbech
- University of Southern Denmark, Campusvej 55, DK-5230, Odense M, Denmark
| | - Heike Schmidt-Posthaus
- Centre for Fish and Wildlife Health, Vetsuisse Faculty, University of Bern, Laenggassstrasse 122, CH-3012, Bern, Switzerland
| | - Angela P Moissl
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, D-69120, Heidelberg, Germany
| | - Mark Hennies
- TECO Development, Marie-Curie-Strasse 1, D-53359, Rheinbach, Germany
| | - Janina Tiedemann
- TECO Development, Marie-Curie-Strasse 1, D-53359, Rheinbach, Germany
| | - Lennart Weltje
- BASF SE, Agricultural Solutions - Ecotoxicology, Speyerer Strasse 2, D-67117, Limburgerhof, Germany
| | - Helmut Segner
- Centre for Fish and Wildlife Health, Vetsuisse Faculty, University of Bern, Laenggassstrasse 122, CH-3012, Bern, Switzerland
| | - Thomas Braunbeck
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, D-69120, Heidelberg, Germany
| |
Collapse
|
38
|
Zindler F, Beedgen F, Brandt D, Steiner M, Stengel D, Baumann L, Braunbeck T. Analysis of tail coiling activity of zebrafish (Danio rerio) embryos allows for the differentiation of neurotoxicants with different modes of action. Ecotoxicol Environ Saf 2019; 186:109754. [PMID: 31606639 DOI: 10.1016/j.ecoenv.2019.109754] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Revised: 10/01/2019] [Accepted: 10/01/2019] [Indexed: 06/10/2023]
Abstract
In (eco)toxicology, there is a critical need for efficient methods to evaluate the neurotoxic potential of environmental chemicals. Recent studies proposed analysis of early coiling activity in zebrafish embryos as a powerful tool for the identification of neurotoxic compounds. In order to demonstrate that the analysis of early tail movements of zebrafish embryos allows for the discrimination of neurotoxicants acting via different mechanisms, the present study investigated the effects of four different neurotoxicants on the embryogenesis (fish embryo toxicity test) and early tail coiling movements of zebrafish embryos. Cadmium predominantly increased the frequency of tail coiling at the late pharyngula stage. Dichlorvos delayed embryonic development and caused convulsive tail movements resulting in prolonged duration of tail coils. Embryos exposed to teratogenic concentrations of fluoxetine and citalopram displayed absence of spontaneous tail movements at 24 h post-fertilization. In contrast, a non-teratogenic test concentration of citalopram decreased coiling frequency at multiple time points. Results demonstrated that the analysis of tail coiling movements of zebrafish embryos has the potential to discriminate neurotoxic compounds with different primary modes of action. In addition, chemical-induced effects on coiling activity were shown to potentially overlap with effects on embryogenesis. Further studies are needed to clarify the interplay of unspecific developmental toxicity of neurotoxic chemicals and effects resulting from specific neurotoxic mechanisms.
Collapse
Affiliation(s)
- Florian Zindler
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, Heidelberg, D-69120, Germany.
| | - Franziska Beedgen
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, Heidelberg, D-69120, Germany
| | - Diana Brandt
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, Heidelberg, D-69120, Germany
| | - Madeleine Steiner
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, Heidelberg, D-69120, Germany
| | - Daniel Stengel
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, Heidelberg, D-69120, Germany
| | - Lisa Baumann
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, Heidelberg, D-69120, Germany
| | - Thomas Braunbeck
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, Heidelberg, D-69120, Germany
| |
Collapse
|
39
|
Zindler F, Beedgen F, Braunbeck T. Time-course of coiling activity in zebrafish (Danio rerio) embryos exposed to ethanol as an endpoint for developmental neurotoxicity (DNT) - Hidden potential and underestimated challenges. Chemosphere 2019; 235:12-20. [PMID: 31254777 DOI: 10.1016/j.chemosphere.2019.06.154] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Revised: 06/19/2019] [Accepted: 06/20/2019] [Indexed: 06/09/2023]
Abstract
Detection of developmental neurotoxicity (DNT) has been recognized as a major challenge by regulatory bodies and science. In search of sensitive and specific test methods, spontaneous tail coiling of embryonic zebrafish has been recommended as a promising tool for identification of DNT-inducing chemicals. The present study was designed to develop a protocol for a prolonged test to study neurotoxicity during the entire development of coiling movement in zebrafish embryos. Ambient illumination was found to modulate coiling activity from the very onset of tail movements representing the earliest behavioral response to light possible in zebrafish. In the dark, embryos displayed increased coiling activity in a way known from photokinesis, a stereotypical element of the visual motor response. Elevated coiling activity during dark phases allows for the development of test strategies that integrate later coiling movements under the control of a further developed nervous system. Furthermore, zebrafish embryos were exposed to ethanol, and coiling activity was analyzed according to the new test protocol. Exposure of embryos to non-teratogenic concentrations of ethanol (0.4-1%) resulted in a delay of the onset of coiling activity and heartbeat. Moreover, ethanol produced a dose-dependent increase in coiling frequency at 26 h post-fertilization, indicating the involvement of neurotoxic mechanisms. Analysis of coiling activity during prolonged exposure allowed for (1) attributing effects on coiling activity to different mechanisms and (2) preventing false interpretation of results. Further research is needed to verify the potential of this test protocol to distinguish between different mechanisms of neurotoxicity.
Collapse
Affiliation(s)
- Florian Zindler
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, Heidelberg, D-69120, Germany.
| | - Franziska Beedgen
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, Heidelberg, D-69120, Germany
| | - Thomas Braunbeck
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, Heidelberg, D-69120, Germany
| |
Collapse
|
40
|
du Plessis B, Regnier T, Combrinck S, Heinrich P, Braunbeck T. Effect of pH on the toxicity of fumonisins towards the RTL-W1 cell line and zebrafish (Danio rerio) embryos. Toxicol Lett 2019; 313:101-107. [DOI: 10.1016/j.toxlet.2019.06.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Revised: 05/31/2019] [Accepted: 06/25/2019] [Indexed: 11/29/2022]
|
41
|
Brotzmann K, von Hellfeld R, Braunbeck T. Teratogenicity in mammals predicted by a non-mammal test system, the zebrafish (Danio rerio) embryo. Reprod Toxicol 2019. [DOI: 10.1016/j.reprotox.2019.07.071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
42
|
Tisler S, Zindler F, Freeling F, Nödler K, Toelgyesi L, Braunbeck T, Zwiener C. Transformation Products of Fluoxetine Formed by Photodegradation in Water and Biodegradation in Zebrafish Embryos ( Danio rerio). Environ Sci Technol 2019; 53:7400-7409. [PMID: 31136157 DOI: 10.1021/acs.est.9b00789] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
The present study investigates the transformation of the antidepressant fluoxetine (FLX) by photo- and biodegradation and shows similarities and differences in transformation products (TPs). TPs were identified using LC-high-resolution mass spectrometry with positive and negative electrospray ionization. In a sunlight simulator, photodegradation was carried out using ultrapure water (pH 6, 8, and 10) and surface water (pH 8) to study the effect of direct and indirect photolysis, respectively. The well-known metabolite norfluoxetine (NFLX) proved to be a minor TP in photolysis (≤2% of degraded FLX). In addition, 26 TPs were detected, which were formed by cleavage of the phenolether bond ( O-dealkylation) which primarily formed 3-(methylamino)-1-phenyl-1-propanol (TP 166) and 4-(trifluoromethyl)phenol, by hydroxylation of the benzyl moiety, by CF3 substitution to benzoic aldehyde/acid, and by adduct formation at the amine group ( N-acylation with aldehydes and carboxylic acids). Higher pH favors the neutral species of FLX and the neutral/anionic species of primary TPs and, therefore, photodegradation. In zebrafish embryos, the bioconcentration factor of FLX was found to be 110, and about 1% of FLX taken up by the embryos was transformed to NFLX. Seven metabolites known from photodegradation and formed by hydrolysis, hydroxylation, and N-acylation as well as three new metabolites formed by N-hydroxylation, N-methylation, and attachment of an amine group were identified in zebrafish embryos. The study highlights the importance of considering a broad range of TPs of FLX in fresh water systems and in ecotoxicity tests and to include TP formation in both environmental processes and metabolism in organisms.
Collapse
Affiliation(s)
- Selina Tisler
- Environmental Analytical Chemistry, ZAG , University of Tübingen , Hölderlinstrasse 12 , 72074 Tübingen , Germany
| | - Florian Zindler
- Aquatic Ecology & Toxicology , Centre for Organismal Studies, University of Heidelberg , Im Neuenheimer Feld 504, Heidelberg 69120 , Germany
| | | | - Karsten Nödler
- TZW: DVGW-Technologiezentrum Wasser , 76139 Karlsruhe , Germany
| | | | - Thomas Braunbeck
- Aquatic Ecology & Toxicology , Centre for Organismal Studies, University of Heidelberg , Im Neuenheimer Feld 504, Heidelberg 69120 , Germany
| | - Christian Zwiener
- Environmental Analytical Chemistry, ZAG , University of Tübingen , Hölderlinstrasse 12 , 72074 Tübingen , Germany
| |
Collapse
|
43
|
Heinrich P, Braunbeck T. Bioavailability of microplastic-bound pollutants in vitro: The role of adsorbate lipophilicity and surfactants. Comp Biochem Physiol C Toxicol Pharmacol 2019; 221:59-67. [PMID: 30940555 DOI: 10.1016/j.cbpc.2019.03.012] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Revised: 03/25/2019] [Accepted: 03/27/2019] [Indexed: 11/30/2022]
Abstract
The potential role of microplastic particles (MPs) as vectors for lipophilic organic pollutants enhancing their uptake by organisms has repeatedly been discussed in the scientific community. Likewise, several studies indicate an important role of surfactants in pollutant-transfer from MP to organisms. Employing polyethylene particles, the bioavailability of three MP-bound inducers of 7-ethoxyresorufin-O-deethylase (EROD) with variable lipophilicity was quantitatively compared via EROD activity in RTL-W1 cells. In addition, non-cytotoxic surfactant concentrations of Pluronic F-127, rhamnolipids, sodium deoxycholate and sodium dodecyl sulfate (SDS) supplemented to the medium were tested for their effects on pollutant desorption from MPs as well as on cellular EROD induction. Bioavailability of MP-bound pollutants was negatively correlated with lipophilicity, and all surfactants were found to modulate the cellular response towards inducers by unidentified mechanisms. After experimental correction for effects on the cellular response, all surfactants except SDS moderately increased desorption of inducer from MPs. Results on the impact of lipophilicity agree with previously published thermodynamic models, indicating that appreciable pollutant desorption from MPs may only occur for substances with comparatively low lipophilicity, the accumulation of which on MPs is negligible in the environment. However, the role of surfactants should be considered further with respect to potential effects on sorption of pollutants to and from MPs.
Collapse
Affiliation(s)
- Patrick Heinrich
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, D-69120 Heidelberg, Germany.
| | - Thomas Braunbeck
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, D-69120 Heidelberg, Germany
| |
Collapse
|
44
|
Castaño A, Bols N, Braunbeck T, Dierickx P, Halder M, Isomaa B, Kawahara K, Lee LEJ, Mothersill C, Pärt P, Repetto G, Sintes JR, Rufli H, Smith R, Wood C, Segner H. The use of Fish Cells in Ecotoxicology: The Report and Recommendations of ECVAM Workshop 47,. Altern Lab Anim 2019; 31:317-51. [PMID: 15612875 DOI: 10.1177/026119290303100314] [Citation(s) in RCA: 106] [Impact Index Per Article: 21.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Argelia Castaño
- Animal Health Research Centre, Spanish National Institute for Food and Agrarian Research and Technology (CISA-INIA), 28130 Valdeolmos, Madrid, Spain
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
45
|
Heinrich P, Braunbeck T. Microplastic testing in vitro: Realistic loading of pollutants, surfactant-free solid surface-dosing and bioanalytical detection using a sensitivity-optimized EROD assay. Toxicol In Vitro 2019; 54:194-201. [DOI: 10.1016/j.tiv.2018.10.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Revised: 09/17/2018] [Accepted: 10/02/2018] [Indexed: 11/28/2022]
|
46
|
Triebskorn R, Braunbeck T, Grummt T, Hanslik L, Huppertsberg S, Jekel M, Knepper TP, Krais S, Müller YK, Pittroff M, Ruhl AS, Schmieg H, Schür C, Strobel C, Wagner M, Zumbülte N, Köhler HR. Relevance of nano- and microplastics for freshwater ecosystems: A critical review. Trends Analyt Chem 2019. [DOI: 10.1016/j.trac.2018.11.023] [Citation(s) in RCA: 178] [Impact Index Per Article: 35.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
|
47
|
Norberg-King TJ, Embry MR, Belanger SE, Braunbeck T, Butler JD, Dorn PB, Farr B, Guiney PD, Hughes SA, Jeffries M, Journel R, Lèonard M, McMaster M, Oris JT, Ryder K, Segner H, Senac T, Der Kraak GV, Whale G, Wilson P. An International Perspective on the Tools and Concepts for Effluent Toxicity Assessments in the Context of Animal Alternatives: Reduction in Vertebrate Use. Environ Toxicol Chem 2018; 37:2745-2757. [PMID: 30359486 PMCID: PMC6534126 DOI: 10.1002/etc.4259] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Revised: 05/03/2018] [Accepted: 08/16/2018] [Indexed: 06/01/2023]
Abstract
Since the 1940s, effluent toxicity testing has been used to assess potential ecological impacts of effluents and help determine necessary treatment options for environmental protection prior to release. Strategic combinations of toxicity tests, analytical tools, and biological monitoring have been developed. Because the number of vertebrates utilized in effluent testing is thought to be much greater than that used for individual chemical testing, there is a new need to develop strategies to reduce the numbers of vertebrates (i.e., fish) used. This need will become more critical as developing nations begin to use vertebrates in toxicity tests to assess effluent quality. A workshop was held to 1) assess the state of science in effluent toxicity testing globally; 2) determine current practices of regulators, industry, private laboratories, and academia; and 3) explore alternatives to vertebrate (fish) testing options and the inclusion of modified/new methods and approaches in the regulatory environment. No single approach was identified, because of a range of factors including regulatory concerns, validity criteria, and wider acceptability of alternatives. However, a suite of strategies in a weight-of-evidence approach would provide the flexibility to meet the needs of the environment, regulators, and the regulated community; and this "toolbox" approach would also support reduced reliance on in vivo fish tests. The present Focus article provides a brief overview of wastewater regulation and effluent testing approaches. Alternative methodologies under development and some of the limitations and barriers to regulatory approaches that can be selected to suit individual country and regional requirements are described and discussed. Environ Toxicol Chem 2018;37:2745-2757. © 2018 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals, Inc. on behalf of SETAC.
Collapse
Affiliation(s)
| | | | | | | | | | | | - Brianna Farr
- Health and Environmental Science Institute, Washington, DC, USA
| | | | | | | | | | | | - Mark McMaster
- Environment and Climate Change Canada, Burlington, ON, Canada
| | | | | | | | | | | | | | | |
Collapse
|
48
|
Zhao H, Di Mauro G, Lungu-Mitea S, Negrini P, Guarino AM, Frigato E, Braunbeck T, Ma H, Lamparter T, Vallone D, Bertolucci C, Foulkes NS. Modulation of DNA Repair Systems in Blind Cavefish during Evolution in Constant Darkness. Curr Biol 2018; 28:3229-3243.e4. [PMID: 30318355 DOI: 10.1016/j.cub.2018.08.039] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2018] [Revised: 07/19/2018] [Accepted: 08/16/2018] [Indexed: 11/18/2022]
Abstract
How the environment shapes the function and evolution of DNA repair systems is poorly understood. In a comparative study using zebrafish and the Somalian blind cavefish, Phreatichthys andruzzii, we reveal that during evolution for millions of years in continuous darkness, photoreactivation DNA repair function has been lost in P. andruzzii. We demonstrate that this loss results in part from loss-of-function mutations in pivotal DNA-repair genes. Specifically, C-terminal truncations in P. andruzzii DASH and 6-4 photolyase render these proteins predominantly cytoplasmic, with consequent loss in their functionality. In addition, we reveal a general absence of light-, UV-, and ROS-induced expression of P. andruzzii DNA-repair genes. This results from a loss of function of the D-box enhancer element, which coordinates and enhances DNA repair in response to sunlight. Our results point to P. andruzzii being the only species described, apart from placental mammals, that lacks the highly evolutionary conserved photoreactivation function. We predict that in the DNA repair systems of P. andruzzii, we may be witnessing the first stages in a process that previously occurred in the ancestors of placental mammals during the Mesozoic era.
Collapse
Affiliation(s)
- Haiyu Zhao
- Institute of Toxicology and Genetics, Karlsruhe Institute of Technology, Hermann-von-Helmholtz Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
| | - Giuseppe Di Mauro
- Institute of Toxicology and Genetics, Karlsruhe Institute of Technology, Hermann-von-Helmholtz Platz 1, 76344 Eggenstein-Leopoldshafen, Germany; Department of Life Science and Biotechnology, University of Ferrara, Via Luigi Borsari 46, 44121 Ferrara, Italy
| | - Sebastian Lungu-Mitea
- Institute of Toxicology and Genetics, Karlsruhe Institute of Technology, Hermann-von-Helmholtz Platz 1, 76344 Eggenstein-Leopoldshafen, Germany; Aquatic Ecology and Toxicology, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld, 69120 Heidelberg, Germany; Department of Biomedical Sciences and Veterinary Public Health, Swedish University of Agricultural Sciences, 75007 Uppsala, Sweden
| | - Pietro Negrini
- Institute of Toxicology and Genetics, Karlsruhe Institute of Technology, Hermann-von-Helmholtz Platz 1, 76344 Eggenstein-Leopoldshafen, Germany; Department of Life Science and Biotechnology, University of Ferrara, Via Luigi Borsari 46, 44121 Ferrara, Italy
| | - Andrea Maria Guarino
- Institute of Toxicology and Genetics, Karlsruhe Institute of Technology, Hermann-von-Helmholtz Platz 1, 76344 Eggenstein-Leopoldshafen, Germany; Department of Biology, University of Naples "Federico II," 80126 Naples, Italy
| | - Elena Frigato
- Department of Life Science and Biotechnology, University of Ferrara, Via Luigi Borsari 46, 44121 Ferrara, Italy
| | - Thomas Braunbeck
- Aquatic Ecology and Toxicology, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld, 69120 Heidelberg, Germany
| | - Hongju Ma
- Botanical Institute, Karlsruhe Institute of Technology, 76128 Karlsruhe, Germany
| | - Tilman Lamparter
- Botanical Institute, Karlsruhe Institute of Technology, 76128 Karlsruhe, Germany
| | - Daniela Vallone
- Institute of Toxicology and Genetics, Karlsruhe Institute of Technology, Hermann-von-Helmholtz Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
| | - Cristiano Bertolucci
- Department of Life Science and Biotechnology, University of Ferrara, Via Luigi Borsari 46, 44121 Ferrara, Italy
| | - Nicholas S Foulkes
- Institute of Toxicology and Genetics, Karlsruhe Institute of Technology, Hermann-von-Helmholtz Platz 1, 76344 Eggenstein-Leopoldshafen, Germany.
| |
Collapse
|
49
|
Heinrich P, Braunbeck T. Genetically engineered zebrafish liver (ZF-L) cells as an in vitro source for zebrafish acetylcholinesterase (zfAChE) for the use in AChE inhibition assays. Toxicol In Vitro 2018; 52:52-59. [DOI: 10.1016/j.tiv.2018.06.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Revised: 05/04/2018] [Accepted: 06/01/2018] [Indexed: 12/14/2022]
|
50
|
Rehberger K, Baumann L, Hecker M, Braunbeck T. Intrafollicular thyroid hormone staining in whole-mount zebrafish (Danio rerio) embryos for the detection of thyroid hormone synthesis disruption. Fish Physiol Biochem 2018; 44:997-1010. [PMID: 29568982 DOI: 10.1007/s10695-018-0488-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2017] [Accepted: 02/26/2018] [Indexed: 06/08/2023]
Abstract
Endocrine-disrupting chemicals are known to impact multiple hormonal axes of vertebrates, among which the thyroid system is crucial for multiple developmental and physiological processes. Thus, the present study focused on the semi-quantitative visualization of intrafollicular triiodothyronine (T3) and thyroxin (T4) in zebrafish embryos as a potential test system for the detection of disrupted thyroid hormone synthesis. To this end, an antibody-based fluorescence double-staining protocol for whole-mount zebrafish embryos and larvae was adapted to simultaneously detect intrafollicular T3 and T4. During normal development until 10 days post-fertilization (dpf), the number of thyroid follicles increased along the ventral aorta. Concentrations of T4 and T3, measured by fluorescence intensity, increased until 6 dpf, but decreased thereafter. Exposure of zebrafish embryos to propylthiouracil (PTU), a known inhibitor of TH synthesis, resulted in a significant decrease in the number of follicles that stained for T3, whereas a trend for increase in follicles that stained for T4 was observed. In contrast, fluorescence intensity for both thyroid hormones decreased significantly after exposure to PTU. Overall, the zebrafish embryo appears to be suitable for the simultaneous visualization and detection of changing intrafollicular TH contents during normal development and after PTU treatment.
Collapse
Affiliation(s)
- Kristina Rehberger
- Centre for Organismal Studies, Aquatic Ecology and Toxicology, University of Heidelberg, Im Neuenheimer Feld 504, 69120, Heidelberg, Germany
- Vetsuisse Faculty, Centre for Fish and Wildlife Health, University of Bern, Länggassstrasse122, 3012, Bern, Switzerland
| | - Lisa Baumann
- Centre for Organismal Studies, Aquatic Ecology and Toxicology, University of Heidelberg, Im Neuenheimer Feld 504, 69120, Heidelberg, Germany.
| | - Markus Hecker
- School of the Environment & Sustainability and Toxicology Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, SK, S7N 5B3, Canada
| | - Thomas Braunbeck
- Centre for Organismal Studies, Aquatic Ecology and Toxicology, University of Heidelberg, Im Neuenheimer Feld 504, 69120, Heidelberg, Germany.
| |
Collapse
|