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Cahova J, Blahova J, Mares J, Hodkovicova N, Sauer P, Kroupova HK, Svobodova Z. Octinoxate as a potential thyroid hormone disruptor - A combination of in vivo and in vitro data. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 856:159074. [PMID: 36181807 DOI: 10.1016/j.scitotenv.2022.159074] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 09/19/2022] [Accepted: 09/23/2022] [Indexed: 06/16/2023]
Abstract
Ultraviolet filters are commonly used in various cosmetic products. Due to their huge consumption ultraviolet filters become a part of the environment. Octinoxate is a commonly used ultraviolet filter that is widely detected in the aquatic environment. In our study, we investigated whether this ultraviolet filter is able to disrupt thyroid hormone regulation after six weeks of exposure in rainbow trout (Oncorhynchus mykiss). Thyroid hormones play crucial role in development and regulation of the organism and its disruption could cause the whole-body imbalance. Our study includes a compilation of in vivo and in vitro tests. The results of the in vivo experiment revealed a significant increase in thyroxine hormone in plasma for the highest tested dose of octinoxate (i.e. 395.6 μg/kg). We examined selected tissues (liver and cranial kidney) to determine the mRNA expression of genes involved in thyroid hormones regulation. The analysis confirmed downregulation of deiodinase 2 mRNA expression for the highest tested dose (i.e. 395.6 μg/kg) and downregulation of paired box 8 mRNA for medium (96 μg/kg) and the highest octinoxate dose (395.6 μg/kg.) only in cranial kidney. In vitro analysis indicated that octinoxate does not elicit (anti-)thyroid activity via thrβ and does not behave as a transthyretin ligand. Based on our results, octinoxate has a potential to act as a thyroid hormone disruptor, but further research required to better understand the entire regulatory mechanism.
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Affiliation(s)
- Jana Cahova
- Department of Animal Protection and Welfare and Veterinary Public Health, Faculty of Veterinary Hygiene and Ecology, University of Veterinary Sciences Brno, Czech Republic
| | - Jana Blahova
- Department of Animal Protection and Welfare and Veterinary Public Health, Faculty of Veterinary Hygiene and Ecology, University of Veterinary Sciences Brno, Czech Republic.
| | - Jan Mares
- Department of Zoology, Fisheries, Hydrobiology and Apiculture, Faculty of AgriSciences, Mendel University in Brno, Czech Republic
| | - Nikola Hodkovicova
- Department of Infectious Diseases and Preventive Medicine, Veterinary Research Institute, Brno, Czech Republic
| | - Pavel Sauer
- University of South Bohemia in České Budějovice, Faculty of Fisheries and Protection of Waters, South Bohemian Research Center of Aquaculture and Biodiversity of Hydrocenoses, Vodňany, Czech Republic
| | - Hana Kocour Kroupova
- University of South Bohemia in České Budějovice, Faculty of Fisheries and Protection of Waters, South Bohemian Research Center of Aquaculture and Biodiversity of Hydrocenoses, Vodňany, Czech Republic
| | - Zdenka Svobodova
- Department of Animal Protection and Welfare and Veterinary Public Health, Faculty of Veterinary Hygiene and Ecology, University of Veterinary Sciences Brno, Czech Republic
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Uemae Y, Sakamoto J, Hidaka Y, Hiratsuka A, Susa T, Kato Y, Suzuki M. Gene expression, function, and diversity of Nkx2-4 in the rainbow trout, Oncorhynchus mykiss. Gen Comp Endocrinol 2014; 206:193-202. [PMID: 25051213 DOI: 10.1016/j.ygcen.2014.07.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Revised: 06/25/2014] [Accepted: 07/13/2014] [Indexed: 11/27/2022]
Abstract
Nkx2 homeodomain transcription factors are involved in various developmental processes and cell specification: e.g. in mammals, NKX2-1 is essential for thyroid-specific gene expression and thyroid morphogenesis. Among Nkx2 proteins, information is still very limited for Nkx2-4. In the present study, we have identified three distinct cDNAs encoding Nkx2-4 isoforms (Nkx2-4a, -b, and -c) from the rainbow trout thyroid tissue, and characterized their transcriptional properties. The trout Nkx2-4 proteins were all predicted to conserve three characteristic domains: the tinman-like amino terminal decapeptide, the NK2 homeodomain, and the NK2-specific domain, and also share 75-89% amino acid similarity. It was shown by dual luciferase assay that Nkx2-4a and Nkx2-4b, but not Nkx2-4c, significantly activated transcription from a cotransfected rat thyroglobulin (TG) promoter. An electrophoretic mobility shift assay indicated that all the Nkx2-4 isoforms could bind to the TG promoter, implying that the faint transcriptional activity of Nkx2-4c might result from some critical amino acid substitution(s) outside the homeodomain. RT-PCR analysis revealed similar tissue distribution patterns for Nkx2-4a and Nkx2-4b mRNAs. Both mRNAs were expressed abundantly in the thyroid, and weakly in the testis. On the other hand, Nkx2-4c mRNA was detected in the ovary as well as in the thyroid. The expression sites of Nkx2-4c mRNA were localized, by in situ hybridization histochemistry, to the ovarian granulosa cells and to the thyroid follicular cells. The results suggest that in the rainbow trout, Nkx2-4a and Nkx2-4b might play a major role in TG gene transcription whereas Nkx2-4c might have some functions in the ovary as well as the thyroid.
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Affiliation(s)
- Youji Uemae
- Department of Biological Science, Graduate School of Science, Shizuoka University, Ohya 836, Shizuoka City, Shizuoka 422-8529, Japan
| | - Joe Sakamoto
- Integrated Bioscience Section, Graduate School of Science and Technology, Shizuoka University, Ohya 836, Shizuoka City, Shizuoka 422-8529, Japan
| | - Yoshie Hidaka
- Integrated Bioscience Section, Graduate School of Science and Technology, Shizuoka University, Ohya 836, Shizuoka City, Shizuoka 422-8529, Japan
| | - Ai Hiratsuka
- Department of Biology, Faculty of Science, Shizuoka University, Ohya 836, Shizuoka City, Shizuoka 422-8529, Japan
| | - Takao Susa
- Department of Life Science, School of Agriculture, Meiji University, 1-1-1 Higashi-mita, Kawasaki, Kanagawa 214-8571, Japan
| | - Yukio Kato
- Department of Life Science, School of Agriculture, Meiji University, 1-1-1 Higashi-mita, Kawasaki, Kanagawa 214-8571, Japan
| | - Masakazu Suzuki
- Department of Biological Science, Graduate School of Science, Shizuoka University, Ohya 836, Shizuoka City, Shizuoka 422-8529, Japan; Integrated Bioscience Section, Graduate School of Science and Technology, Shizuoka University, Ohya 836, Shizuoka City, Shizuoka 422-8529, Japan; Department of Biology, Faculty of Science, Shizuoka University, Ohya 836, Shizuoka City, Shizuoka 422-8529, Japan.
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