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HARA Y, SHODA A, YONOICHI S, ISHIDA Y, MURATA M, KIMURA M, ITO M, NUNOBIKI S, YOSHIMOTO A, MANTANI Y, YOKOYAMA T, HIRANO T, IKENAKA Y, TABUCHI Y, HOSHI N. No-observed-adverse-effect-level (NOAEL) clothianidin, a neonicotinoid pesticide, impairs hippocampal memory and motor learning associated with alteration of gene expression in cerebellum. J Vet Med Sci 2024; 86:340-348. [PMID: 38311399 PMCID: PMC10963099 DOI: 10.1292/jvms.23-0516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Accepted: 01/24/2024] [Indexed: 02/10/2024] Open
Abstract
Neonicotinoid pesticides (NNs) have been associated with numerous neurobehavioral effects in rodents, raising concerns about their impact on cognitive function. Clothianidin (CLO), a type of NN, was orally administered to male mice (10 weeks old, C57BL/6N) at the no-observed-adverse-effect level (NOAEL) of 50 mg/kg/day as indicated in the pesticide risk assessment report. Behavioral tests (novel location recognition and rotarod tests) evaluated hippocampal memory and cerebellar motor learning. After each test, plasma monoamines (3-methoxytyramine, histamine, serotonin, tryptamine) were measured by LC-ESI/MS/MS (Liquid chromatography-electrospray ionization/tandem mass spectrometry), and cerebellar mRNA expression was quantified by microarray and qRT-PCR analyses. The NOAEL of CLO was found to impair hippocampal memory, leading to decreased spontaneous locomotor activity and motor function. We reported, for the first time, multiple alterations of gene expression in the cerebellum associated with motor dysfunction.
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Affiliation(s)
- Yukako HARA
- Laboratory of Animal Molecular Morphology, Department of Animal Science, Graduate School of Agricultural Science, Kobe University, Hyogo, Japan
| | - Asuka SHODA
- Laboratory of Animal Molecular Morphology, Department of Animal Science, Graduate School of Agricultural Science, Kobe University, Hyogo, Japan
| | - Sakura YONOICHI
- Laboratory of Animal Molecular Morphology, Department of Animal Science, Graduate School of Agricultural Science, Kobe University, Hyogo, Japan
| | - Yuya ISHIDA
- Laboratory of Animal Molecular Morphology, Department of Animal Science, Graduate School of Agricultural Science, Kobe University, Hyogo, Japan
| | - Midori MURATA
- Laboratory of Animal Molecular Morphology, Department of Animal Science, Graduate School of Agricultural Science, Kobe University, Hyogo, Japan
| | - Mako KIMURA
- Laboratory of Animal Molecular Morphology, Department of Animal Science, Graduate School of Agricultural Science, Kobe University, Hyogo, Japan
| | - Makiko ITO
- Laboratory of Animal Molecular Morphology, Department of Animal Science, Graduate School of Agricultural Science, Kobe University, Hyogo, Japan
| | - Sarika NUNOBIKI
- Laboratory of Animal Molecular Morphology, Department of Animal Science, Graduate School of Agricultural Science, Kobe University, Hyogo, Japan
| | - Ayano YOSHIMOTO
- Laboratory of Animal Molecular Morphology, Department of Animal Science, Graduate School of Agricultural Science, Kobe University, Hyogo, Japan
| | - Youhei MANTANI
- Laboratory of Histophysiology, Department of Animal Science, Graduate School of Agricultural Science, Kobe University, Hyogo, Japan
| | - Toshifumi YOKOYAMA
- Laboratory of Animal Molecular Morphology, Department of Animal Science, Graduate School of Agricultural Science, Kobe University, Hyogo, Japan
| | - Tetsushi HIRANO
- Faculty of Pharmaceutical Sciences, University of Toyama, Toyama, Japan
| | - Yoshinori IKENAKA
- Laboratory of Toxicology, Department of Environmental Veterinary Sciences, Faculty of Veterinary Medicine, Hokkaido University, Hokkaido, Japan
- Translational Research Unit, Veterinary Teaching Hospital, Faculty of Veterinary Medicine, Hokkaido University, Hokkaido, Japan
- One Health Research Center, Hokkaido University, Hokkaido, Japan
- Water Research Group, Unit for Environmental Sciences and Management, North-West University, Potchefstroom, South Africa
| | - Yoshiaki TABUCHI
- Faculty of Pharmaceutical Sciences, University of Toyama, Toyama, Japan
| | - Nobuhiko HOSHI
- Laboratory of Animal Molecular Morphology, Department of Animal Science, Graduate School of Agricultural Science, Kobe University, Hyogo, Japan
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2
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Kimura E, Suzuki G, Uramaru N, Kakeyama M, Maekawa F. 2-Chloro-3,7,8-tribromodibenzofuran as a new environmental pollutant inducing atypical ultrasonic vocalization in infant mice. Toxicol Res (Camb) 2023; 12:999-1004. [PMID: 37915473 PMCID: PMC10615804 DOI: 10.1093/toxres/tfad069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2023] [Revised: 07/22/2023] [Accepted: 08/08/2023] [Indexed: 11/03/2023] Open
Abstract
Epidemiological and experimental studies indicate that maternal exposure to environmental pollutants impairs the cognitive and motor functions of offspring in humans and laboratory animals. Infant ultrasonic vocalizations (USVs), the communicative behavior of pups toward caregivers, are impaired in rodent models of neurodevelopmental disorders, suggesting a useful method to evaluate the developmental neurotoxicity of environmental pollutants. Therefore, we investigated USVs emitted by mouse pups of dams exposed to 2-chloro-3,7,8-tribromodibenzofuran (TeXDF) and 1,2,3,7,8-pentabromodibenzofuran (PeBDF), which are detected in the actual environment. The USV duration and number in the pups born to dams administered with TeXDF 40 μg/kg body weight (b.w.), but not 8 μg/kg b.w., on gestational day (GD) 12.5, were significantly lower than those in the corresponding pups on postnatal days 3-9. Conversely, there was no statistical change in the USVs emitted by the pups of dams administered with PeBDF 35 or 175 μg/kg b.w. on GD 12.5. To examine whether maternal exposure leads to behavioral impairments in adulthood, we analyzed exploratory behaviors in a novel environment using IntelliCage, a fully automated testing apparatus for group-housed mice. Neither TeXDF nor PeBDF exposure induced significant differences in offspring exploration. Considered together, our findings revealed that TeXDF induces atypical USV emission in infant mice, suggesting the importance of further studies on the risk assessment of mixed brominated/chlorinated dibenzo-p-dioxins and dibenzofurans.
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Affiliation(s)
- Eiki Kimura
- Health and Environmental Risk Research Division, National Institute for Environmental Studies, Tsukuba 305-8506, Japan
- Japan Society for the Promotion of Science, Tokyo 102-0083, Japan
- Department of Environmental Health, University of Fukui School of Medical Sciences, Fukui 910-1193, Japan
| | - Go Suzuki
- Material Cycles Division, National Institute for Environmental Studies, Tsukuba 305-8506, Japan
| | - Naoto Uramaru
- Division of Pharmaceutical Health Biosciences, Nihon Pharmaceutical University, Saitama 362-0806, Japan
| | - Masaki Kakeyama
- Faculty of Human Sciences, Waseda University, Saitama 359-1192, Japan
| | - Fumihiko Maekawa
- Health and Environmental Risk Research Division, National Institute for Environmental Studies, Tsukuba 305-8506, Japan
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3
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Cintrón-Rivera LG, Oulette G, Prakki A, Burns NM, Patel R, Cyr R, Plavicki J. Exposure to the persistent organic pollutant 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD, dioxin) disrupts development of the zebrafish inner ear. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2023; 259:106539. [PMID: 37086653 PMCID: PMC10519160 DOI: 10.1016/j.aquatox.2023.106539] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 04/07/2023] [Accepted: 04/09/2023] [Indexed: 05/03/2023]
Abstract
Dioxins are a class of highly toxic and persistent environmental pollutants that have been shown through epidemiological and laboratory-based studies to act as developmental teratogens. 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), the most potent dioxin congener, has a high affinity for the aryl hydrocarbon receptor (AHR), a ligand activated transcription factor. TCDD-induced AHR activation during development impairs nervous system, cardiac, and craniofacial development. Despite the robust phenotypes previously reported, the characterization of developmental malformations and our understanding of the molecular targets mediating TCDD-induced developmental toxicity remains limited. In zebrafish, TCDD-induced craniofacial malformations are produced, in part, by the downregulation of SRY-box transcription factor 9b (sox9b), a member of the SoxE gene family. sox9b, along with fellow SoxE gene family members sox9a and sox10, have important functions in the development of the otic placode, the otic vesicle, and, ultimately, the inner ear. Given that sox9b is a known target of TCDD and that transcriptional interactions exist among SoxE genes, we asked whether TCDD exposure impaired the development of the zebrafish auditory system, specifically the otic vesicle, which gives rise to the sensory components of the inner ear. Using immunohistochemistry, in vivo confocal imaging, and time-lapse microscopy, we assessed the impact of TCDD exposure on zebrafish otic vesicle development. We found exposure resulted in structural deficits, including incomplete pillar fusion and altered pillar topography, leading to defective semicircular canal development. The observed structural deficits were accompanied by reduced collagen type II expression in the ear. Together, our findings reveal the otic vesicle as a novel target of TCDD-induced toxicity, suggest that the function of multiple SoxE genes may be affected by TCDD exposure, and provide insight into how environmental contaminants contribute to congenital malformations.
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Affiliation(s)
- Layra G Cintrón-Rivera
- Department of Pathology and Laboratory Medicine, Brown University, 70 Ship St, Providence, RI, 02903, USA
| | - Gabrielle Oulette
- Department of Pathology and Laboratory Medicine, Brown University, 70 Ship St, Providence, RI, 02903, USA
| | - Aishwarya Prakki
- Department of Pathology and Laboratory Medicine, Brown University, 70 Ship St, Providence, RI, 02903, USA
| | - Nicole M Burns
- Department of Pathology and Laboratory Medicine, Brown University, 70 Ship St, Providence, RI, 02903, USA
| | - Ratna Patel
- Department of Pathology and Laboratory Medicine, Brown University, Providence, RI, USA
| | - Rachel Cyr
- Department of Pathology and Laboratory Medicine, Brown University, Providence, RI, USA
| | - Jessica Plavicki
- Department of Pathology and Laboratory Medicine, Brown University, 70 Ship St, Providence, RI, 02903, USA.
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4
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Cintr N-Rivera LG, Oulette G, Prakki A, Burns NM, Patel R, Cyr R, Plavicki J. Exposure to the persistent organic pollutant 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD, dioxin) disrupts development of the zebrafish inner ear. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.14.532434. [PMID: 36993549 PMCID: PMC10054988 DOI: 10.1101/2023.03.14.532434] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/28/2023]
Abstract
Dioxins are a class of highly toxic and persistent environmental pollutants that have been shown through epidemiological and laboratory-based studies to act as developmental teratogens. 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), the most potent dioxin congener, has a high affinity for the aryl hydrocarbon receptor (AHR), a ligand activated transcription factor. TCDD-induced AHR activation during development impairs nervous system, cardiac, and craniofacial development. Despite the robust phenotypes previously reported, the characterization of developmental malformations and our understanding of the molecular targets mediating TCDD-induced developmental toxicity remains limited. In zebrafish, TCDD-induced craniofacial malformations are produced, in part, by the downregulation of SRY-box transcription factor 9b ( sox9b ), a member of the SoxE gene family. sox9b , along with fellow SoxE gene family members sox9a and sox10 , have important functions in the development of the otic placode, the otic vesicle, and, ultimately, the inner ear. Given that sox9b in a known target of TCDD and that transcriptional interactions exist among SoxE genes, we asked whether TCDD exposure impaired the development of the zebrafish auditory system, specifically the otic vesicle, which gives rise to the sensory components of the inner ear. Using immunohistochemistry, in vivo confocal imaging, and time-lapse microscopy, we assessed the impact of TCDD exposure on zebrafish otic vesicle development. We found exposure resulted in structural deficits, including incomplete pillar fusion and altered pillar topography, leading to defective semicircular canal development. The observed structural deficits were accompanied by reduced collagen type II expression in the ear. Together, our findings reveal the otic vesicle as a novel target of TCDD-induced toxicity, suggest that the function of multiple SoxE genes may be affected by TCDD exposure, and provide insight into how environmental contaminants contribute to congenital malformations. Highlights The zebrafish ear is necessary to detect changes in motion, sound, and gravity.Embryos exposed to TCDD lack structural components of the developing ear.TCDD exposure impairs formation of the fusion plate and alters pillar topography.The semicircular canals of the ear are required to detect changes in movement.Following TCDD exposure embryos fail to establish semicircular canals.
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5
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Martin NR, Patel R, Kossack ME, Tian L, Camarillo MA, Cintrón-Rivera LG, Gawdzik JC, Yue MS, Nwagugo FO, Elemans LMH, Plavicki JS. Proper modulation of AHR signaling is necessary for establishing neural connectivity and oligodendrocyte precursor cell development in the embryonic zebrafish brain. Front Mol Neurosci 2022; 15:1032302. [PMID: 36523606 PMCID: PMC9745199 DOI: 10.3389/fnmol.2022.1032302] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Accepted: 10/24/2022] [Indexed: 12/03/2022] Open
Abstract
2,3,7,8-tetrachlorodibenzo-[p]-dioxin (TCDD) is a persistent global pollutant that exhibits a high affinity for the aryl hydrocarbon receptor (AHR), a ligand activated transcription factor. Epidemiological studies have associated AHR agonist exposure with multiple human neuropathologies. Consistent with the human data, research studies using laboratory models have linked pollutant-induced AHR activation to disruptions in learning and memory as well as motor impairments. Our understanding of endogenous AHR functions in brain development is limited and, correspondingly, scientists are still determining which cell types and brain regions are sensitive to AHR modulation. To identify novel phenotypes resulting from pollutant-induced AHR activation and ahr2 loss of function, we utilized the optically transparent zebrafish model. Early embryonic TCDD exposure impaired embryonic brain morphogenesis, resulted in ventriculomegaly, and disrupted neural connectivity in the optic tectum, habenula, cerebellum, and olfactory bulb. Altered neural network formation was accompanied by reduced expression of synaptic vesicle 2. Loss of ahr2 function also impaired nascent network development, but did not affect gross brain or ventricular morphology. To determine whether neural AHR activation was sufficient to disrupt connectivity, we used the Gal4/UAS system to express a constitutively active AHR specifically in differentiated neurons and observed disruptions only in the cerebellum; thus, suggesting that the phenotypes resulting from global AHR activation likely involve multiple cell types. Consistent with this hypothesis, we found that TCDD exposure reduced the number of oligodendrocyte precursor cells and their derivatives. Together, our findings indicate that proper modulation of AHR signaling is necessary for the growth and maturation of the embryonic zebrafish brain.
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Affiliation(s)
- Nathan R. Martin
- Department of Pathology and Laboratory Medicine, Brown University, Providence, RI, United States
| | - Ratna Patel
- Department of Pathology and Laboratory Medicine, Brown University, Providence, RI, United States
| | - Michelle E. Kossack
- Department of Pathology and Laboratory Medicine, Brown University, Providence, RI, United States
| | - Lucy Tian
- Department of Pathology and Laboratory Medicine, Brown University, Providence, RI, United States
| | - Manuel A. Camarillo
- Department of Pathology and Laboratory Medicine, Brown University, Providence, RI, United States
| | - Layra G. Cintrón-Rivera
- Department of Pathology and Laboratory Medicine, Brown University, Providence, RI, United States
| | - Joseph C. Gawdzik
- Molecular and Environmental Toxicology Center, University of Wisconsin at Madison, Madison, WI, United States,Division of Pharmaceutical Sciences, University of Wisconsin at Madison, Madison, WI, United States
| | - Monica S. Yue
- Molecular and Environmental Toxicology Center, University of Wisconsin at Madison, Madison, WI, United States,Division of Pharmaceutical Sciences, University of Wisconsin at Madison, Madison, WI, United States
| | - Favour O. Nwagugo
- Department of Biology, University of Maryland Baltimore County, Baltimore, MD, United States
| | - Loes M. H. Elemans
- Division of Toxicology, Institute for Risk Assessment Sciences (IRAS), Utrecht University, Utrecht, Netherlands
| | - Jessica S. Plavicki
- Department of Pathology and Laboratory Medicine, Brown University, Providence, RI, United States,*Correspondence: Jessica S. Plavicki,
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6
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Du Y, Shi Y, Wang X, Song H, Wang X, Hao Y, Zhao Y, Guo X, Shi M, Gong M, Song L, Wang S, Gao Y, Shi H. Hippocampal Semaphorin 3B Improves Depression-like Behaviours in Mice by Upregulating Synaptic Plasticity and Inhibiting Neuronal Apoptosis. J Neurochem 2022; 163:133-148. [PMID: 35892177 DOI: 10.1111/jnc.15680] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2021] [Revised: 07/03/2022] [Accepted: 07/20/2022] [Indexed: 12/01/2022]
Abstract
Depression is a global health problem, and there is a pressing need for a better understanding of its pathogenesis. Semaphorin 3B (Sema 3B) is an important axon guidance molecule that is primarily expressed in neurons and contributes to synaptic plasticity. Our previous studies using a high-throughput microarray assay suggested that Sema 3B expression was tremendously decreased during the development of depression, but the specific role and mechanisms of Sema 3B in depression are still unknown. Herein, we report that levels of Sema 3B protein are decreased in the hippocampus and serum of chronic mild stress (CMS)-treated mice. Increasing the levels of Sema 3B, either by injecting AAV-Sema 3B into the hippocampus or by injecting recombinant Sema 3B protein into the lateral ventricles, alleviated CMS-induced depression-like behaviours and enhanced the resistance to acute stress by increasing dendritic spine density in hippocampal neurons. In contrast, interfering the function of Sema 3B by injecting anti-Sema 3B antibody into the lateral ventricles decreased the resistance to acute stress. In vitro, corticosterone (CORT) treatment decreased survival rate and protein levels of Sema 3B and synapse-associated proteins in HT22 cells. Overexpression of Sema 3B improved the decreased survival rate caused by CORT by inhibiting apoptosis and increasing levels of synaptic-associated proteins. And knockdown of Sema 3B reduces the cellular resistance to CORT and the levels of synapse-associated proteins. These findings represent the first evidence for the neuroprotective mechanism of Sema 3B against stresses, suggesting that Sema 3B could be a promising novel target for the prevention and treatment of depression.
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Affiliation(s)
- Yuru Du
- Hebei Key Laboratory of Neurophysiology, Shijiazhuang, China.,Neuroscience Research Center, Institute of Medical and Health Science, Hebei Medical University, Shijiazhuang, China
| | - Yun Shi
- Hebei Key Laboratory of Neurophysiology, Shijiazhuang, China.,Neuroscience Research Center, Institute of Medical and Health Science, Hebei Medical University, Shijiazhuang, China.,Department of Biochemistry and Molecular Biology, The Key Laboratory of Neural and Vascular Biology, Ministry of Education of, China, Shijiazhuang, Hebei
| | - Xi Wang
- Hebei Key Laboratory of Neurophysiology, Shijiazhuang, China.,Neuroscience Research Center, Institute of Medical and Health Science, Hebei Medical University, Shijiazhuang, China.,Department of Endocrinology, The Third Affiliated Hospital of Hebei Medical University, Shijiazhuang, China
| | - Han Song
- Hebei Key Laboratory of Neurophysiology, Shijiazhuang, China.,Neuroscience Research Center, Institute of Medical and Health Science, Hebei Medical University, Shijiazhuang, China
| | - Xinhao Wang
- Hebei Key Laboratory of Neurophysiology, Shijiazhuang, China.,Neuroscience Research Center, Institute of Medical and Health Science, Hebei Medical University, Shijiazhuang, China
| | - Ying Hao
- Hebei Key Laboratory of Neurophysiology, Shijiazhuang, China.,Neuroscience Research Center, Institute of Medical and Health Science, Hebei Medical University, Shijiazhuang, China
| | - Ye Zhao
- Hebei Key Laboratory of Neurophysiology, Shijiazhuang, China.,Neuroscience Research Center, Institute of Medical and Health Science, Hebei Medical University, Shijiazhuang, China
| | - Xiangfei Guo
- Hebei Key Laboratory of Neurophysiology, Shijiazhuang, China.,Neuroscience Research Center, Institute of Medical and Health Science, Hebei Medical University, Shijiazhuang, China
| | - Mengxu Shi
- Hebei Key Laboratory of Neurophysiology, Shijiazhuang, China.,Neuroscience Research Center, Institute of Medical and Health Science, Hebei Medical University, Shijiazhuang, China
| | - Miao Gong
- Hebei Key Laboratory of Neurophysiology, Shijiazhuang, China.,Neuroscience Research Center, Institute of Medical and Health Science, Hebei Medical University, Shijiazhuang, China
| | - Li Song
- Hebei Key Laboratory of Neurophysiology, Shijiazhuang, China.,Neuroscience Research Center, Institute of Medical and Health Science, Hebei Medical University, Shijiazhuang, China
| | - Sheng Wang
- Hebei Key Laboratory of Neurophysiology, Shijiazhuang, China.,Neuroscience Research Center, Institute of Medical and Health Science, Hebei Medical University, Shijiazhuang, China
| | - Yuan Gao
- Hebei Key Laboratory of Neurophysiology, Shijiazhuang, China.,Neuroscience Research Center, Institute of Medical and Health Science, Hebei Medical University, Shijiazhuang, China
| | - Haishui Shi
- Hebei Key Laboratory of Neurophysiology, Shijiazhuang, China.,Neuroscience Research Center, Institute of Medical and Health Science, Hebei Medical University, Shijiazhuang, China
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7
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Re DB, Yan B, Calderón-Garcidueñas L, Andrew AS, Tischbein M, Stommel EW. A perspective on persistent toxicants in veterans and amyotrophic lateral sclerosis: identifying exposures determining higher ALS risk. J Neurol 2022; 269:2359-2377. [PMID: 34973105 PMCID: PMC9021134 DOI: 10.1007/s00415-021-10928-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Revised: 11/30/2021] [Accepted: 12/01/2021] [Indexed: 02/07/2023]
Abstract
Multiple studies indicate that United States veterans have an increased risk of developing amyotrophic lateral sclerosis (ALS) compared to civilians. However, the responsible etiological factors are unknown. In the general population, specific occupational (e.g. truck drivers, airline pilots) and environmental exposures (e.g. metals, pesticides) are associated with an increased ALS risk. As such, the increased prevalence of ALS in veterans strongly suggests that there are exposures experienced by military personnel that are disproportionate to civilians. During service, veterans may encounter numerous neurotoxic exposures (e.g. burn pits, engine exhaust, firing ranges). So far, however, there is a paucity of studies investigating environmental factors contributing to ALS in veterans and even fewer assessing their exposure using biomarkers. Herein, we discuss ALS pathogenesis in relation to a series of persistent neurotoxicants (often emitted as mixtures) including: chemical elements, nanoparticles and lipophilic toxicants such as dioxins, polycyclic aromatic hydrocarbons and polychlorinated biphenyls. We propose these toxicants should be directly measured in veteran central nervous system tissue, where they may have accumulated for decades. Specific toxicants (or mixtures thereof) may accelerate ALS development following a multistep hypothesis or act synergistically with other service-linked exposures (e.g. head trauma/concussions). Such possibilities could explain the lower age of onset observed in veterans compared to civilians. Identifying high-risk exposures within vulnerable populations is key to understanding ALS etiopathogenesis and is urgently needed to act upon modifiable risk factors for military personnel who deserve enhanced protection during their years of service, not only for their short-term, but also long-term health.
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Affiliation(s)
- Diane B Re
- Department of Environmental Health Science, Center for Motor Neuron Biology and Disease, Columbia University, New York, NY, USA
| | - Beizhan Yan
- Department of Geochemistry, Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY, USA
| | - Lilian Calderón-Garcidueñas
- Department Biomedical Sciences, College of Health, University of Montana, Missoula, MT, USA
- Universidad del Valle de México, Mexico City, Mexico
| | - Angeline S Andrew
- Department of Neurology, Geisel School of Medicine at Dartmouth, Dartmouth-Hitchcock Medical Center, Lebanon, NH, USA
| | - Maeve Tischbein
- Department of Neurology, Geisel School of Medicine at Dartmouth, Dartmouth-Hitchcock Medical Center, Lebanon, NH, USA
| | - Elijah W Stommel
- Department of Neurology, Geisel School of Medicine at Dartmouth, Dartmouth-Hitchcock Medical Center, Lebanon, NH, USA.
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8
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Kimura E, Suzuki G, Uramaru N, Kakeyama M, Maekawa F. Liver-specific decrease in Tff3 gene expression in infant mice perinatally exposed to 2,3,7,8-tetrabromodibenzofuran or 2,3,7,8-tetrachlorodibenzo-p-dioxin. J Appl Toxicol 2021; 42:305-317. [PMID: 34254344 DOI: 10.1002/jat.4220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 06/09/2021] [Accepted: 06/28/2021] [Indexed: 11/05/2022]
Abstract
Polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/DFs) are byproducts of brominated flame retardants and can cause adverse health effects. Although exposure to polychlorinated (PC) DD/DFs induces toxic effects, including liver injury and neurobehavioral disorder, little is known about toxicities associated with PBDD/DF exposure. Thus, we examined effects of perinatal exposure to brominated congener on the infant mouse. Gene expression in several organs, such as the liver and brain, was analyzed in mouse offspring born to dams administered 2,3,7,8-tetrabromodibenzofuran (TBDF; 9 or 45 μg/kg body weight) or 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD; 3 μg/kg body weight) on gestational day 12.5. An increase in liver size was observed in TBDF- or TCDD-exposed offspring in infancy. Gene microarray analysis revealed that 163 and 36 genes were markedly upregulated and downregulated, respectively, in the liver of TBDF-exposed mice compared with those in vehicle-treated mice on postnatal day (PND) 5. Significant increases in Cyp1a1, Cyp1a2, Fmo3, and Pnliprp1 and decreases in Tff3, Ocstamp, Kcnk16, and Lgals2 mRNA levels in TBDF-exposed offspring on PNDs 5 and 12 were confirmed by quantitative PCR. In particular, a significant reduction in Tff3 mRNA in the liver, but not in the brain, small intestine, colon, and kidney, was observed in offspring perinatally exposed to TBDF or TCDD. Ultrasonic calls of TBDF- or TCDD-exposed offspring on PNDs 3-5 were impaired. Taken together, perinatal exposure to polyhalogenated dioxin/furan congeners disrupts gene expression patterns in the liver and ultrasonic calling during infancy. These results suggest that liver injury may contribute to neurobehavioral disorder.
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Affiliation(s)
- Eiki Kimura
- Center for Health and Environmental Risk Research, National Institute for Environmental Studies, Tsukuba, Japan.,Japan Society for the Promotion of Science, Tokyo, Japan
| | - Go Suzuki
- Center for Material Cycles and Waste Management Research, National Institute for Environmental Studies, Tsukuba, Japan
| | - Naoto Uramaru
- Department of Pharmaceutical Sciences, Nihon Pharmaceutical University, Saitama, Japan
| | - Masaki Kakeyama
- Faculty of Human Sciences, Waseda University, Saitama, Japan
| | - Fumihiko Maekawa
- Center for Health and Environmental Risk Research, National Institute for Environmental Studies, Tsukuba, Japan
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9
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Kimura E, Kohda M, Maekawa F, Fujii-Kuriyama Y, Tohyama C. Neurons expressing the aryl hydrocarbon receptor in the locus coeruleus and island of Calleja major are novel targets of dioxin in the mouse brain. Histochem Cell Biol 2021; 156:147-163. [PMID: 33963922 PMCID: PMC8397641 DOI: 10.1007/s00418-021-01990-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/21/2021] [Indexed: 12/14/2022]
Abstract
The aryl hydrocarbon receptor (AhR) acts as a receptor that responds to ligands, including dioxin. The AhR-ligand complex translocates from the cytoplasm into the nucleus to induce gene expression. Because dioxin exposure impairs cognitive and neurobehavioral functions, AhR-expressing neurons need to be identified for elucidation of the dioxin neurotoxicity mechanism. Immunohistochemistry was performed to detect AhR-expressing neurons in the mouse brain and confirm the specificity of the anti-AhR antibody using Ahr-/- mice. Intracellular distribution of AhR and expression level of AhR-target genes, Cyp1a1, Cyp1b1, and Ahr repressor (Ahrr), were analyzed by immunohistochemistry and quantitative RT-PCR, respectively, using mice exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). The mouse brains were shown to harbor AhR in neurons of the locus coeruleus (LC) and island of Calleja major (ICjM) during developmental period in Ahr+/+ mice but not in Ahr-/- mice. A significant increase in nuclear AhR of ICjM neurons but not LC neurons was found in 14-day-old mice compared to 5- and 7-day-old mice. AhR was significantly translocated into the nucleus in LC and ICjM neurons of TCDD-exposed adult mice. Additionally, the expression levels of Cyp1a1, Cyp1b1, and Ahrr genes in the brain, a surrogate of TCDD in the tissue, were significantly increased by dioxin exposure, suggesting that dioxin-activated AhR induces gene expression in LC and ICjM neurons. This histochemical study shows the ligand-induced nuclear translocation of AhR at the single-neuron level in vivo. Thus, the neurotoxicological significance of the dioxin-activated AhR in the LC and ICjM warrants further studies.
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Affiliation(s)
- Eiki Kimura
- Laboratory of Environmental Health Sciences, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan. .,Center for Health and Environmental Risk Research, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, 305-8506, Japan. .,Research Fellow, Japan Society for the Promotion of Science (JSPS), 5-3-1 Kojimachi, Chiyoda-ku, Tokyo, 102-0083, Japan.
| | - Masanobu Kohda
- Laboratory of Environmental Health Sciences, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan.,Center for Health and Environmental Risk Research, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, 305-8506, Japan
| | - Fumihiko Maekawa
- Center for Health and Environmental Risk Research, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, 305-8506, Japan
| | - Yoshiaki Fujii-Kuriyama
- Medical Research Institute, Molecular Epidemiology, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8510, Japan
| | - Chiharu Tohyama
- Laboratory of Environmental Health Sciences, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan. .,Center for Health and Environmental Risk Research, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, 305-8506, Japan. .,Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, 305-8575, Japan.
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10
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Gileadi TE, Swamy AK, Hore Z, Horswell S, Ellegood J, Mohan C, Mizuno K, Lundebye AK, Giese KP, Stockinger B, Hogstrand C, Lerch JP, Fernandes C, Basson MA. Effects of Low-Dose Gestational TCDD Exposure on Behavior and on Hippocampal Neuron Morphology and Gene Expression in Mice. ENVIRONMENTAL HEALTH PERSPECTIVES 2021; 129:57002. [PMID: 33956508 PMCID: PMC8101924 DOI: 10.1289/ehp7352] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Revised: 02/19/2021] [Accepted: 03/29/2021] [Indexed: 05/03/2023]
Abstract
BACKGROUND 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is a persistent and toxic environmental pollutant. Gestational exposure to TCDD has been linked to cognitive and motor deficits, and increased incidence of autism spectrum disorder (ASD) traits in children. Most animal studies of these neurodevelopmental effects involve acute TCDD exposure, which does not model typical exposure in humans. OBJECTIVES The aim of the study was to establish a dietary low-dose gestational TCDD exposure protocol and performed an initial characterization of the effects on offspring behavior, neurodevelopmental phenotypes, and gene expression. METHODS Throughout gestation, pregnant C57BL/6J mice were fed a diet containing a low dose of TCDD (9 ng TCDD/kg body weight per day) or a control diet. The offspring were tested in a battery of behavioral tests, and structural brain alterations were investigated by magnetic resonance imaging. The dendritic morphology of pyramidal neurons in the hippocampal Cornu Ammonis (CA)1 area was analyzed. RNA sequencing was performed on hippocampi of postnatal day 14 TCDD-exposed and control offspring. RESULTS TCDD-exposed females displayed subtle deficits in motor coordination and reversal learning. Volumetric difference between diet groups were observed in regions of the hippocampal formation, mammillary bodies, and cerebellum, alongside higher dendritic arborization of pyramidal neurons in the hippocampal CA1 region of TCDD-exposed females. RNA-seq analysis identified 405 differentially expressed genes in the hippocampus, enriched for genes with functions in regulation of microtubules, axon guidance, extracellular matrix, and genes regulated by SMAD3. DISCUSSION Exposure to 9 ng TCDD/kg body weight per day throughout gestation was sufficient to cause specific behavioral and structural brain phenotypes in offspring. Our data suggest that alterations in SMAD3-regulated microtubule polymerization in the developing postnatal hippocampus may lead to an abnormal morphology of neuronal dendrites that persists into adulthood. These findings show that environmental low-dose gestational exposure to TCDD can have significant, long-term impacts on brain development and function. https://doi.org/10.1289/EHP7352.
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Affiliation(s)
- Talia E. Gileadi
- Centre for Craniofacial and Regenerative Biology, King’s College London, London, UK
| | - Abhyuday K. Swamy
- Centre for Craniofacial and Regenerative Biology, King’s College London, London, UK
| | - Zoe Hore
- Social, Genetic & Developmental Psychiatry Centre, Institute of Psychiatry, Psychology & Neuroscience, King’s College London, London, UK
| | - Stuart Horswell
- Department of Bioinformatics and Biostatistics, The Francis Crick Institute, London, UK
| | - Jacob Ellegood
- Mouse Imaging Centre (MICe), Hospital for Sick Children, Toronto, Ontario, Canada
| | - Conor Mohan
- Centre for Craniofacial and Regenerative Biology, King’s College London, London, UK
| | - Keiko Mizuno
- Department of Basic and Clinical Neuroscience, King’s College London, London, UK
| | | | - K. Peter Giese
- Department of Basic and Clinical Neuroscience, King’s College London, London, UK
| | | | | | - Jason P. Lerch
- Mouse Imaging Centre (MICe), Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada
- Wellcome Centre for Integrative Neuroimaging, University of Oxford, Oxford, UK
| | - Cathy Fernandes
- Social, Genetic & Developmental Psychiatry Centre, Institute of Psychiatry, Psychology & Neuroscience, King’s College London, London, UK
- MRC Centre for Neurodevelopmental Disorders, King’s College London, London, UK
| | - M. Albert Basson
- Centre for Craniofacial and Regenerative Biology, King’s College London, London, UK
- MRC Centre for Neurodevelopmental Disorders, King’s College London, London, UK
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11
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Sha R, Chen Y, Wang Y, Luo Y, Liu Y, Ma Y, Li Y, Xu L, Xie HQ, Zhao B. Gestational and lactational exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin in mice: Neurobehavioral effects on female offspring. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 752:141784. [PMID: 32889265 DOI: 10.1016/j.scitotenv.2020.141784] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Revised: 08/12/2020] [Accepted: 08/17/2020] [Indexed: 06/11/2023]
Abstract
Emerging evidence suggests that perinatal dioxin exposure affects neurodevelopment and impairs multiple brain functions, including cognitive, language, learning and emotion, in the offspring. However, the impacts of gestational and lactational exposure to dioxin on behavior and related molecular events are still not fully understood. In this study, female C57BL/6J mice were orally administered three doses of 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin (TCDD) (0.1 or 10 μg/kg body weight (bw)) during the pregnancy and lactation periods. The locomotion, exploration and anxiety-related behaviors were examined by an open field test of the young adult female offspring at postnatal day 68. We found that the maternal TCDD exposure, particularly at a low dose, increased movement ability, novelty-exploration and certain anxiety-related behaviors in the offspring. Such hyperactivity-like behaviors were accompanied by the upregulation of certain genes associated with cholinergic neurotransmission or synaptogenesis in the offspring brain. In accordance with the potential enhancement of cholinergic neurotransmission due to the gene upregulations, the enzymatic activity of acetylcholinesterase was decreased, which might lead to excess acetylcholine and consequent hyper-excitation at the synapses. Thus, we found that gestational and lactational TCDD exposure at low dose caused hyperactivity-like behaviors in young adult female offspring and speculated the enhancement of cholinergic neurotransmission and synaptogenesis as potential molecular events underlying the neurobehavioral effects.
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Affiliation(s)
- Rui Sha
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yangsheng Chen
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yijing Wang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yali Luo
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yiyun Liu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yongchao Ma
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yunping Li
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Li Xu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Heidi Qunhui Xie
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Bin Zhao
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
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12
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Kimura E, Suzuki G, Uramaru N, Endo T, Maekawa F. Behavioral impairments in infant and adult mouse offspring exposed to 2,3,7,8-tetrabromodibenzofuran in utero and via lactation. ENVIRONMENT INTERNATIONAL 2020; 142:105833. [PMID: 32559560 DOI: 10.1016/j.envint.2020.105833] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2020] [Revised: 04/19/2020] [Accepted: 05/22/2020] [Indexed: 06/11/2023]
Abstract
Polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/DFs) have been unintentionally produced and emitted from the lifecycle of products containing brominated flame retardants, such as polybrominated diphenyl ether, which is suspected to cause developmental neurotoxicity (DNT). Although it is plausible that PBDD/DFs can also induce DNT, information regarding their neurotoxic potential is currently limited. Hence, in the present study, we examined the effects of in utero and lactational exposure to brominated dibenzofurans on infant and adult offspring behavior to understand the mechanism of PBDD/DFs toxicity and detect effective behavioral endpoints in DNT assessment. We analyzed the behavior of mouse offspring born to dams administered 2,3,7,8-tetrabromodibenzofuran (2,3,7,8-TeBDF; dose of 0, 9, or 45 μg/kg) or 2,3,8-tribromodibenzofuran (2,3,8-TrBDF; dose of 0, 75.6, or 378 μg/kg) on gestational day 12.5. In mouse offspring born to dams exposed to 2,3,7,8-TeBDF, the exploratory behavior in a novel environment in adulthood and ultrasonic vocalization (USV) during infancy were significantly reduced. Additionally, AhR-target genes, such as Cyp1a1, were induced in the liver of 2,3,7,8-TeBDF-exposed offspring in a dose-dependent manner. Conversely, no significant changes in the infant and adult behaviors and expression level of AhR-target genes were observed in the 2,3,8-TrBDF-exposed offspring. These results suggest that 2,3,7,8-TeBDF can induce DNT and that the analysis of exploratory behavior in a novel environment and USV may be useful endpoints to assess DNT of dioxin-related substances.
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Affiliation(s)
- Eiki Kimura
- Center for Health and Environmental Risk Research, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba 305-8506, Japan; Japan Society for the Promotion of Science, 5-3-1 Kojimachi, Chiyoda-ku, Tokyo 102-0083, Japan
| | - Go Suzuki
- Center for Material Cycles and Waste Management Research, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba 305-8506, Japan
| | - Naoto Uramaru
- Nihon Pharmaceutical University, 10281 Komuro Ina-machi, Kitaadachi-gun, Saitama 362-0806, Japan
| | - Toshihiro Endo
- Phenovance Research & Technology, 5-4-19-302A, Kashiwanoha, Kashiwa, Chiba 277-0882, Japan
| | - Fumihiko Maekawa
- Center for Health and Environmental Risk Research, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba 305-8506, Japan.
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13
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Nghiem GT, Nishijo M, Pham TN, Ito M, Pham TT, Tran AH, Nishimaru H, Nishino Y, Nishijo H. Adverse effects of maternal dioxin exposure on fetal brain development before birth assessed by neonatal electroencephalography (EEG) leading to poor neurodevelopment; a 2-year follow-up study. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 667:718-729. [PMID: 30849612 DOI: 10.1016/j.scitotenv.2019.02.395] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2018] [Revised: 02/13/2019] [Accepted: 02/25/2019] [Indexed: 06/09/2023]
Abstract
We previously reported the adverse effects of perinatal dioxin exposure on child neurodevelopment around a former US military airbase in Vietnam. In the present study, we investigated the effects of maternal dioxin exposure on fetal brain development, which may predict neurodevelopmental outcomes in early childhood. A total of 55 newborns with mothers from dioxin-contaminated areas were recruited in the prefecture hospital in Bien Hoa, Vietnam. Dioxins in maternal breast milk collected 1 month after birth were used as a maternal exposure marker. Relative powers and coherence were computed from neonatal electroencephalogram (EEG) records during active sleep stages. Relationships between the EEG parameters and dioxin exposure markers were analyzed using linear regression and a general linear model after adjusting for gestational age, body length, and head circumference of infants at birth. Using data from 47 infants whose neurodevelopment was examined in a 2-year follow-up study, associations between EEG parameters and neurodevelopment were analyzed after adjusting for confounding factors. On the right frontal and parietal regions, relative delta powers were significantly decreased, and relative alpha and beta powers were significantly increased with increasing dioxin exposure. Increases in delta power and decreases in alpha power on the right frontal and parietal regions were associated with an increase in language scores at 2 years of age. Furthermore, intra- and inter-hemispheric coherence in theta and alpha bands were positively and inversely correlated with dioxin exposure, respectively, and increased intra-coherence in the right hemisphere was associated with lower language scores. These findings suggest that prenatal dioxin exposure affects neuronal activity and functional connectivity between brain regions, and may lead to poor language development.
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Affiliation(s)
- GiangThi Thuy Nghiem
- System Emotional Science, Graduate School of Medicine, University of Toyama, Toyama 930-0194, Japan
| | - Muneko Nishijo
- Department of Public Health, Kanazawa Medical University, Ishikawa 920-0293, Japan.
| | - Thao Ngoc Pham
- Department of Public Health, Kanazawa Medical University, Ishikawa 920-0293, Japan
| | - Mika Ito
- Department of Obstetrics and Gynecology, University of Toyama, Toyama 930-0194, Japan
| | - Tai The Pham
- Biomedical and Pharmaceutical Research Center, Vietnamese Military Medical University, Hanoi, Viet Nam
| | - Anh Hai Tran
- Biomedical and Pharmaceutical Research Center, Vietnamese Military Medical University, Hanoi, Viet Nam
| | - Hiroshi Nishimaru
- System Emotional Science, Graduate School of Medicine, University of Toyama, Toyama 930-0194, Japan
| | - Yoshikazu Nishino
- Department of Public Health, Kanazawa Medical University, Ishikawa 920-0293, Japan
| | - Hisao Nishijo
- System Emotional Science, Graduate School of Medicine, University of Toyama, Toyama 930-0194, Japan
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14
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Zhang HJ, Liu YN, Xian P, Ma J, Sun YW, Chen JS, Chen X, Tang NJ. Maternal exposure to TCDD during gestation advanced sensory-motor development, but induced impairments of spatial learning and memory in adult male rat offspring. CHEMOSPHERE 2018; 212:678-686. [PMID: 30176550 DOI: 10.1016/j.chemosphere.2018.08.118] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Revised: 08/15/2018] [Accepted: 08/23/2018] [Indexed: 05/19/2023]
Abstract
2,3,7,8-Tetrachlorodibenzo-p-Dioxin (TCDD) is an endocrine disrupting chemical (EDC) with high persistency. Even a low amount can pass the placental barrier during gestational exposure. Exposure to TCDD exposure can impair the development of the nervous system in children, leading to impaired learning ability in later-life. But the changes in neurobehavioral developments in infancy and childhood caused by TCDD are unknown. Pregnant Sprague-Dawley rats were given a consecutive daily dose of TCDD (200 or 800 ng/day/kg) or an equivalent volume of vehicle by gavage on gestational days 8-14 (GD 8-14) as the prenatal TCDD exposure model. In the offspring, early neurobehavioral development was assessed at postnatal day 5 (PND5) and eye-opening was monitored from PND10 onwards. Adult male offspring was tested by Morris Water Maze for spatial memory and learning ability evaluation. Hippocampus Nissl's staining and astrocyte GFAP immunohistochemistry were used to evaluate the activity of astrocytes. The results of the behavioral tests showed that gestational TCDD exposure induced premature motor activity and earlier eyes-opening, but lead to serious deficits of spatial memory and learning ability in the adult male offspring. Morphology and number of neurons in the hippocampus CA1 region was not affected, while the activity of astrocytes in the same region was significantly reduced. These data indicate that perinatal TCDD exposure induced premature neurobehavioral development but impaired the spatial learning and memory in adult male rat offspring. The decreased activity of astrocytes in the hippocampus may play a role in these adverse effects.
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Affiliation(s)
- Hua-Jing Zhang
- Department of Occupational and Environmental Health, School of Public Health, Tianjin Medical University, Tianjin, 300070, China.
| | - Ya-Nan Liu
- Department of Occupational and Environmental Health, School of Public Health, Tianjin Medical University, Tianjin, 300070, China.
| | - Ping Xian
- Department of Occupational and Environmental Health, School of Public Health, Tianjin Medical University, Tianjin, 300070, China.
| | - Jing Ma
- Tianjin Cardiovascular Diseases Institute, Tianjin Chest Hospital, Tianjin, 300350, China.
| | - Ya-Wen Sun
- Department of Occupational and Environmental Health, School of Public Health, Tianjin Medical University, Tianjin, 300070, China.
| | - Jing-Shan Chen
- Department of Technology and Science, Tianjin Medical University General Hospital, Tianjin, 300052, China.
| | - Xi Chen
- Department of Occupational and Environmental Health, School of Public Health, Tianjin Medical University, Tianjin, 300070, China.
| | - Nai-Jun Tang
- Department of Occupational and Environmental Health, School of Public Health, Tianjin Medical University, Tianjin, 300070, China.
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15
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Erdemli ME, Yigitcan B, Gul M, Bag HG, Gul S, Aksungur Z. Thymoquinone is protective against 2,3,7,8-tetrachlorodibenzo-p-dioxin induced hepatotoxicity. Biotech Histochem 2018; 93:453-462. [PMID: 29701106 DOI: 10.1080/10520295.2018.1453549] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022] Open
Abstract
We investigated changes in rat liver tissues following administration of thymoquinone (TQ) against 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) induced hepatotoxicity. Fifty rats were assigned randomly to five groups of 10 as follows: control, corn oil, TCDD, TQ and TCDD + TQ. Biochemical and histopathological analyses were conducted on liver tissue. We found that 30 day TCDD administration caused histopathological changes in liver including thickening of Glisson's capsule, intracytoplasmic vacuolization in hepatocytes, sinusoidal dilation, vascular and sinusoidal congestion and inflammatory cell infiltration. TCDD administration increased malondialdehyde (MDA), total oxidant status (TOS), alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (ALP) levels in rat liver tissue and reduced glutathione (GSH), superoxide dismutase (SOD), catalase (CAT) and total antioxidant status (TAS) levels compared to all other groups. In the TQ treated group, GSH, SOD, CAT and TAS levels increased compared to all other groups. MDA, TOS, ALT, AST, ALP levels decreased compared to all other groups. Our histological findings were consistent with the biochemical findings. The oxidative and histologic effects of TCDD were eliminated by TQ treatment. TCDD administration caused oxidative stress in rat liver and TQ administered with TCDD prevented TCDD induced hepatotoxicity. TQ could be considered an alternative anti-TCDD toxicity agent.
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Affiliation(s)
- M E Erdemli
- a Department of Medical Biochemistry, Medical Faculty , Nigde Omer Halisdemir University , Nigde
| | - B Yigitcan
- b Departments of Histology and Embryology, Medical Faculty , Inonu University , Malatya
| | - M Gul
- b Departments of Histology and Embryology, Medical Faculty , Inonu University , Malatya
| | - H G Bag
- c Department of Biostatistics, Medical Faculty , Inonu University , Malatya
| | - S Gul
- b Departments of Histology and Embryology, Medical Faculty , Inonu University , Malatya
| | - Z Aksungur
- d Department of Medical Biochemistry, Medical Faculty , Inonu University , Malatya , Turkey
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16
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Kimura E, Tohyama C. Vocalization as a novel endpoint of atypical attachment behavior in 2,3,7,8-tetrachlorodibenzo-p-dioxin-exposed infant mice. Arch Toxicol 2018; 92:1741-1749. [PMID: 29445839 DOI: 10.1007/s00204-018-2176-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2018] [Accepted: 02/08/2018] [Indexed: 01/24/2023]
Abstract
Mammalian attachment behaviors, such as crying, are essential for infant survival by receiving food, protection, and warmth from caregivers. Ultrasonic vocalization (USV) of infant rodents functions to promote maternal proximity. Impaired USV emission has been reported in mouse models of autism spectrum disorder, suggesting that USV is associated with higher brain function. In utero and lactational dioxin exposure is known to induce higher brain function abnormalities in adulthood; however, whether perinatal dioxin exposure affects behavior during infancy is unclear. Therefore, we studied the impact of dioxin exposure on USV emission in infant mice born to dams treated with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD; 0.6 or 3.0 µg/kg) on gestational day 12.5. On postnatal days 3-9, USVs of the offspring were recorded for 1 min using a microphone in a sound-attenuated chamber. The total USV and mean call durations in infant mice exposed to 3.0 µg/kg, but not 0.6 µg/kg, were shorter than those in the control mice. In addition, the percentages of complicated call types (i.e., chevron and wave) in mice exposed to 3.0 µg/kg were decreased. Dioxin-induced gene expression changes occurred in the brains of mice exposed to 3.0 µg/kg; however, body weight, motor activity, and vocal fold structure were not significantly affected. These results suggest that infant USV is a useful behavioral endpoint in developmental neurotoxicity assessment that may be used to evaluate effects of chemical exposure on the infant-caregiver interaction.
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Affiliation(s)
- Eiki Kimura
- Laboratory of Environmental Health Sciences, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
- Center for Health and Environmental Risk Research, National Institute for Environmental Studies, Tsukuba, Japan
- Research Fellow of Japan Society for the Promotion of Science, Tokyo, Japan
| | - Chiharu Tohyama
- Laboratory of Environmental Health Sciences, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
- Faculty of Medicine, University of Tsukuba, Tsukuba, Japan.
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17
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van Dongen J, Bonder MJ, Dekkers KF, Nivard MG, van Iterson M, Willemsen G, Beekman M, van der Spek A, van Meurs JBJ, Franke L, Heijmans BT, van Duijn CM, Slagboom PE, Boomsma DI. DNA methylation signatures of educational attainment. NPJ SCIENCE OF LEARNING 2018; 3:7. [PMID: 30631468 PMCID: PMC6220239 DOI: 10.1038/s41539-018-0020-2] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Revised: 11/18/2017] [Accepted: 02/09/2018] [Indexed: 05/09/2023]
Abstract
Educational attainment is a key behavioural measure in studies of cognitive and physical health, and socioeconomic status. We measured DNA methylation at 410,746 CpGs (N = 4152) and identified 58 CpGs associated with educational attainment at loci characterized by pleiotropic functions shared with neuronal, immune and developmental processes. Associations overlapped with those for smoking behaviour, but remained after accounting for smoking at many CpGs: Effect sizes were on average 28% smaller and genome-wide significant at 11 CpGs after adjusting for smoking and were 62% smaller in never smokers. We examined sources and biological implications of education-related methylation differences, demonstrating correlations with maternal prenatal folate, smoking and air pollution signatures, and associations with gene expression in cis, dynamic methylation in foetal brain, and correlations between blood and brain. Our findings show that the methylome of lower-educated people resembles that of smokers beyond effects of their own smoking behaviour and shows traces of various other exposures.
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Affiliation(s)
- Jenny van Dongen
- Department of Biological Psychology, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Marc Jan Bonder
- Department of Genetics, University of Groningen, University Medical Centre Groningen, Groningen, The Netherlands
| | - Koen F. Dekkers
- Molecular Epidemiology section, Leiden University Medical Center, Leiden, The Netherlands
| | - Michel G. Nivard
- Department of Biological Psychology, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Maarten van Iterson
- Molecular Epidemiology section, Leiden University Medical Center, Leiden, The Netherlands
| | - Gonneke Willemsen
- Department of Biological Psychology, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Marian Beekman
- Molecular Epidemiology section, Leiden University Medical Center, Leiden, The Netherlands
| | - Ashley van der Spek
- Department of Epidemiology, Genetic Epidemiology Unit, Erasmus Medical Center, Rotterdam, The Netherlands
| | | | - Lude Franke
- Department of Genetics, University of Groningen, University Medical Centre Groningen, Groningen, The Netherlands
| | - Bastiaan T. Heijmans
- Molecular Epidemiology section, Leiden University Medical Center, Leiden, The Netherlands
| | - Cornelia M. van Duijn
- Department of Epidemiology, Genetic Epidemiology Unit, Erasmus Medical Center, Rotterdam, The Netherlands
| | - P. Eline Slagboom
- Molecular Epidemiology section, Leiden University Medical Center, Leiden, The Netherlands
| | - Dorret I. Boomsma
- Department of Biological Psychology, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
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18
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Xu T, Xie HQ, Li Y, Xia Y, Chen Y, Xu L, Wang L, Zhao B. CDC42 expression is altered by dioxin exposure and mediated by multilevel regulations via AhR in human neuroblastoma cells. Sci Rep 2017; 7:10103. [PMID: 28860601 PMCID: PMC5578991 DOI: 10.1038/s41598-017-10311-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Accepted: 08/08/2017] [Indexed: 02/05/2023] Open
Abstract
Emerging evidence has shown that dioxin causes dysregulation of microRNAs (miRs) in a variety of tissues or cells. However, little is known about dioxin effects on neuronal miRs expression. In the present study, 277 differentially expressed miRs were identified by miRs microarray analysis in 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD, at 10−10 M) treated SK-N-SH neuroblastoma cells. Among them, 53 miRs exhibited changes of more than 0.4-fold. Consistent with the microarray data, we verified the induction effect of TCDD on hsa-miR-608 expression, which is a primate-specific miR associated with brain functions. Bioinformatics analysis showed involvement of hsa-miR-608 in cytoskeleton organization, in which one of the hsa-miR-608 target genes, Cell Division Cycle 42 (CDC42), might play a role. We also confirmed induction of CDC42 expression by TCDD in SK-N-SH cells. TCDD induced the expression of CDC42 mRNA in hsa-miR-608 inhibitor transfected cells more obviously than in control cells, suggesting involvement of both transcriptional and post-transcriptional mechanisms in the TCDD-induced CDC42 regulation. Furthermore, CH223191, an antagonist of the aryl hydrocarbon receptor (AhR), counteracted TCDD-induced hsa-miR-608 and CDC42 expression. These results indicated that AhR not only mediates transcriptional induction of CDC42, but also hsa-miR-608-induced post-transcriptional regulation of CDC42 in dioxin treated neuroblastoma cells.
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Affiliation(s)
- Tuan Xu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China.,University of Chinese Academy of Sciences, Beijing, 100085, China
| | - Heidi Q Xie
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China.,University of Chinese Academy of Sciences, Beijing, 100085, China
| | - Yunping Li
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China.,University of Chinese Academy of Sciences, Beijing, 100085, China
| | - Yingjie Xia
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China.,University of Chinese Academy of Sciences, Beijing, 100085, China
| | - Yangsheng Chen
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China.,University of Chinese Academy of Sciences, Beijing, 100085, China
| | - Li Xu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China.,University of Chinese Academy of Sciences, Beijing, 100085, China
| | - Lingyun Wang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China.,University of Chinese Academy of Sciences, Beijing, 100085, China
| | - Bin Zhao
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China. .,University of Chinese Academy of Sciences, Beijing, 100085, China.
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19
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Kimura E, Kubo KI, Endo T, Ling W, Nakajima K, Kakeyama M, Tohyama C. Impaired dendritic growth and positioning of cortical pyramidal neurons by activation of aryl hydrocarbon receptor signaling in the developing mouse. PLoS One 2017; 12:e0183497. [PMID: 28820910 PMCID: PMC5562321 DOI: 10.1371/journal.pone.0183497] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Accepted: 08/05/2017] [Indexed: 11/24/2022] Open
Abstract
The basic helix-loop-helix (bHLH) transcription factors exert multiple functions in mammalian cerebral cortex development. The aryl hydrocarbon receptor (AhR), a member of the bHLH-Per-Arnt-Sim subfamily, is a ligand-activated transcription factor reported to regulate nervous system development in both invertebrates and vertebrates, but the functions that AhR signaling pathway may have for mammalian cerebral cortex development remains elusive. Although the endogenous ligand involved in brain developmental process has not been identified, the environmental pollutant dioxin potently binds AhR and induces abnormalities in higher brain function of laboratory animals. Thus, we studied how activation of AhR signaling influences cortical development in mice. To this end, we produced mice expressing either constitutively active-AhR (CA-AhR), which has the capacity for ligand-independent activation of downstream genes, or AhR, which requires its ligands for activation. In brief, CA-AhR-expressing plasmid and AhR-expressing plasmid were each transfected into neural stems cells in the developing cerebrum by in utero electroporation on embryonic day 14.5. On postnatal day 14, mice transfected in utero with CA-AhR, but not those transfected with AhR, exhibited drastically reduced dendritic arborization of layer II/III pyramidal neurons and impaired neuronal positioning in the developing somatosensory cortex. The effects of CA-AhR were observed for dendrite development but not for the commissural fiber projection, suggesting a preferential influence on dendrites. The present results indicate that over-activation of AhR perturbs neuronal migration and morphological development in mammalian cortex, supporting previous observations of impaired dendritic structure, cortical dysgenesis, and behavioral abnormalities following perinatal dioxin exposure.
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Affiliation(s)
- Eiki Kimura
- Laboratory of Environmental Health Sciences, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
- Center for Health and Environmental Risk Research, National Institute for Environmental Studies, Tsukuba, Japan
- Research Fellow of Japan Society for the Promotion of Science, Tokyo, Japan
| | - Ken-ichiro Kubo
- Department of Anatomy, Keio University School of Medicine, Tokyo, Japan
| | - Toshihiro Endo
- Laboratory of Environmental Health Sciences, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
- Department of Neurochemistry, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Wenting Ling
- Laboratory of Environmental Health Sciences, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Kazunori Nakajima
- Department of Anatomy, Keio University School of Medicine, Tokyo, Japan
| | - Masaki Kakeyama
- Laboratory of Environmental Health Sciences, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
- Laboratory for Systems Neuroscience and Preventive Medicine, Faculty of Human Sciences, Waseda University, Tokorozawa, Japan
| | - Chiharu Tohyama
- Laboratory of Environmental Health Sciences, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
- Department of Anatomy and Embryology, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
- * E-mail:
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20
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Kimura E, Kubo KI, Endo T, Nakajima K, Kakeyama M, Tohyama C. Excessive activation of AhR signaling disrupts neuronal migration in the hippocampal CA1 region in the developing mouse. J Toxicol Sci 2017; 42:25-30. [PMID: 28070106 DOI: 10.2131/jts.42.25] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The aryl hydrocarbon receptor (AhR) avidly binds dioxin, a ubiquitous environmental contaminant. Disruption of downstream AhR signaling has been reported to alter neuronal development, and rodent offspring exposed to dioxin during gestation and lactation showed abnormalities in learning and memory, emotion, and social behavior. However, the mechanism behind the disrupted AhR signaling and developmental neurotoxicity induced by xenobiotic ligands remains elusive. Therefore, we studied how excessive AhR activation affects neuronal migration in the hippocampal CA1 region of the developing mouse brain. We transfected constitutively active (CA)-AhR, AhR, or control vector plasmids into neurons via in utero electroporation on gestational day 14 and analyzed neuronal positioning in the hippocampal CA1 region of offspring on postnatal day 14. CA-AhR transfection affected neuronal positioning, whereas no change was observed in AhR-transfected or control hippocampus. These results suggest that constitutively activated AhR signaling disrupts neuronal migration during hippocampal development. Further studies are needed to investigate whether such developmental disruption in the hippocampus leads to the abnormal cognition and behavior of rodent offspring upon maternal exposure to AhR xenobiotic ligands.
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Affiliation(s)
- Eiki Kimura
- Laboratory of Environmental Health Sciences, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo
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21
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Kimura E, Tohyama C. Embryonic and Postnatal Expression of Aryl Hydrocarbon Receptor mRNA in Mouse Brain. Front Neuroanat 2017; 11:4. [PMID: 28223923 PMCID: PMC5293765 DOI: 10.3389/fnana.2017.00004] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Accepted: 01/17/2017] [Indexed: 12/21/2022] Open
Abstract
Aryl hydrocarbon receptor (AhR), a member of the basic helix-loop-helix-Per-Arnt-Sim transcription factor family, plays a critical role in the developing nervous system of invertebrates and vertebrates. Dioxin, a ubiquitous environmental pollutant, avidly binds to this receptor, and maternal exposure to dioxin has been shown to impair higher brain functions and dendritic morphogenesis, possibly via an AhR-dependent mechanism. However, there is little information on AhR expression in the developing mammalian brain. To address this issue, the present study analyzed AhR mRNA expression in the brains of embryonic, juvenile, and adult mice by reverse transcription (RT)-PCR and in situ hybridization. In early brain development (embryonic day 12.5), AhR transcript was detected in the innermost cortical layer. The mRNA was also expressed in the hippocampus, cerebral cortex, cerebellum, olfactory bulb, and rostral migratory stream on embryonic day 18.5, postnatal days 3, 7, and 14, and in 12-week-old (adult) mice. Hippocampal expression was abundant in the CA1 and CA3 pyramidal and dentate gyrus granule cell layers, where expression level of AhR mRNA in 12-week old is higher than that in 7-day old. These results reveal temporal and spatial patterns of AhR mRNA expression in the mouse brain, providing the information that may contribute to the elucidation of the physiologic and toxicologic significance of AhR in the developing brain.
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Affiliation(s)
- Eiki Kimura
- Laboratory of Environmental Health Sciences, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of TokyoTokyo, Japan; Environmental Biology Laboratory, Faculty of Medicine, University of TsukubaTsukuba, Japan
| | - Chiharu Tohyama
- Laboratory of Environmental Health Sciences, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of TokyoTokyo, Japan; Environmental Biology Laboratory, Faculty of Medicine, University of TsukubaTsukuba, Japan
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