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Watanabe Y, Abe H, Nakajima K, Ideta-Otsuka M, Igarashi K, Woo GH, Yoshida T, Shibutani M. Aberrant Epigenetic Gene Regulation in GABAergic Interneuron Subpopulations in the Hippocampal Dentate Gyrus of Mouse Offspring Following Developmental Exposure to Hexachlorophene. Toxicol Sci 2019; 163:13-25. [PMID: 29301063 PMCID: PMC5917777 DOI: 10.1093/toxsci/kfx291] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Maternal hexachlorophene (HCP) exposure causes transient disruption of hippocampal neurogenesis in mouse offspring. We examined epigenetically hypermethylated and downregulated genes related to this HCP-induced disrupted neurogenesis. Mated female mice were dietary exposed to 0 or 100 ppm HCP from gestational day 6 to postnatal day (PND) 21 on weaning. The hippocampal dentate gyrus of male offspring was subjected to methyl-capture sequencing and real-time reverse transcription-polymerase chain reaction analyses on PND 21. Validation analyses on methylation identified three genes, Dlx4, Dmrt1, and Plcb4, showing promoter-region hypermethylation. Immunohistochemically, DLX4+, DMRT1+, and PLCB4+ cells in the dentate hilus co-expressed GAD67, a γ-aminobutyric acid (GABA)ergic neuron marker. HCP decreased all of three subpopulations as well as GAD67+ cells on PND 21. PLCB4+ cells also co-expressed the metabotropic glutamate receptor, GRM1. HCP also decreased transcript level of synaptic plasticity-related genes in the dentate gyrus and immunoreactive granule cells for synaptic plasticity-related ARC. On PND 77, all immunohistochemical cellular density changes were reversed, whereas the transcript expression of the synaptic plasticity-related genes fluctuated. Thus, HCP-exposed offspring transiently reduced the number of GABAergic interneurons. Among them, subpopulations expressing DLX4, DMRT1, or PLCB4 were transiently reduced in number through an epigenetic mechanism. Considering the role of the Dlx gene family in GABAergic interneuron migration and differentiation, the decreased number of DLX4+ cells may be responsible for reducing those GABAergic interneurons regulating neurogenesis. The effect on granule cell synaptic plasticity was sustained until the adult stage, and reduced GABAergic interneurons active in GRM1–PLCB4 signaling may be responsible for the suppression on weaning.
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Affiliation(s)
- Yousuke Watanabe
- Laboratory of Veterinary Pathology, Division of Animal Life Science, Institute of Agriculture, Tokyo University of Agriculture and Technology, Fuchu-shi, Tokyo 183-8509, Japan.,Pathogenetic Veterinary Science, United Graduate School of Veterinary Sciences, Gifu University, Gifu-shi, Gifu 501-1193, Japan
| | - Hajime Abe
- Laboratory of Veterinary Pathology, Division of Animal Life Science, Institute of Agriculture, Tokyo University of Agriculture and Technology, Fuchu-shi, Tokyo 183-8509, Japan
| | - Kota Nakajima
- Laboratory of Veterinary Pathology, Division of Animal Life Science, Institute of Agriculture, Tokyo University of Agriculture and Technology, Fuchu-shi, Tokyo 183-8509, Japan.,Pathogenetic Veterinary Science, United Graduate School of Veterinary Sciences, Gifu University, Gifu-shi, Gifu 501-1193, Japan
| | - Maky Ideta-Otsuka
- Life Science Tokyo Advanced Research Center (L-StaR), Hoshi University School of Pharmacy and Pharmaceutical Sciences, Shinagawa-ku, Tokyo 142-5801, Japan
| | - Katsuhide Igarashi
- Life Science Tokyo Advanced Research Center (L-StaR), Hoshi University School of Pharmacy and Pharmaceutical Sciences, Shinagawa-ku, Tokyo 142-5801, Japan
| | - Gye-Hyeong Woo
- Laboratory of Histopathology, Department of Clinical Laboratory Science, Semyung University, Jecheon-si, Chungbuk 27136, Republic of Korea
| | - Toshinori Yoshida
- Laboratory of Veterinary Pathology, Division of Animal Life Science, Institute of Agriculture, Tokyo University of Agriculture and Technology, Fuchu-shi, Tokyo 183-8509, Japan
| | - Makoto Shibutani
- Laboratory of Veterinary Pathology, Division of Animal Life Science, Institute of Agriculture, Tokyo University of Agriculture and Technology, Fuchu-shi, Tokyo 183-8509, Japan.,Institute of Global Innovation Research, Tokyo University of Agriculture and Technology, Fuchu-shi, Tokyo 183-8509, Japan
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Eriksson P, Darnerud PO. Distribution and retention of some chlorinated hydrocarbons and a phthalate in the mouse brain during the pre-weaning period. Toxicology 1985; 37:189-203. [PMID: 3934796 DOI: 10.1016/0300-483x(85)90082-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
In a quantitative retaining study and a whole-body autoradiographic study 5 14C-labelled compounds, bis-(4-chlorophenyl)trichloroethane (DDT), 2,2',4,4',5,5'-hexachlorobiphenyl (6-CB), hexachlorophene (HCP), polychlorohexadecane (PCHD) and diethylhexylphthalate (DEHP) were each administered to mice at the age of 3, 10 and 20 days. The mice were killed 24 h or 7 days after treatment and the amount of radioactivity in the whole brain was measured and its distribution studied. The retention of radioactivity was most pronounced in mice receiving DDT, PCHD, and 6-CB during the tenth day of life. Here the level of radioactivity 7 days after treatment was nearly as high as that observed after 24 h (ratio between 0.86 and 0.74). In contrast, HCP showed a rapid elimination from the brain and was hardly retained at all in the 20-day-old mouse brain. The retention of DEHP in the brain was minimal. Some of the autoradiographic sections were also subjected to myelin staining. Large amounts of radioactivity were found in the myelinated areas of the brain after HCP and PCHD administration. DDT and 6-CB showed a more even distribution within the brain and were not particularly concentrated in the myelin. There was no obvious relationship between the lipophilicity of the parent compounds and their retention in the brain.
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Brandt I, Dencker L, Larsson KS, Siddall RA. Placental transfer of hexachlorophene (HCP) in the marmoset monkey (Callithrix jacchus). ACTA PHARMACOLOGICA ET TOXICOLOGICA 1983; 52:310-3. [PMID: 6408890 DOI: 10.1111/j.1600-0773.1983.tb01106.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Autoradiography was used to study the distribution of 2,2'-14C-methylene-bis-(3,4,6-trichlorophenol) (HCP) in pregnant marmoset monkeys in early (day 30-50) and late (around day 120) gestation and in a newborn (11 days old) pup. Radioactivity was present in the conceptus at all stages of gestation, although the foetal concentration was lower than the maternal. In the embryo an accumulation was observed in the neural tube and in the embryonic membranes. In the late foetus and newborn monkey the highest concentration of radioactivity was found in the liver and the intestinal contents. The brain of the adult and newborn animals showed low concentration. A partial blood-brain barrier was present in the late foetus but, in relation to other tissues, the foetal brain concentration was higher than that of the mother.
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