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Alcaide Martin A, Mayerl S. Local Thyroid Hormone Action in Brain Development. Int J Mol Sci 2023; 24:12352. [PMID: 37569727 PMCID: PMC10418487 DOI: 10.3390/ijms241512352] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Revised: 07/28/2023] [Accepted: 07/30/2023] [Indexed: 08/13/2023] Open
Abstract
Proper brain development essentially depends on the timed availability of sufficient amounts of thyroid hormone (TH). This, in turn, necessitates a tightly regulated expression of TH signaling components such as TH transporters, deiodinases, and TH receptors in a brain region- and cell-specific manner from early developmental stages onwards. Abnormal TH levels during critical stages, as well as mutations in TH signaling components that alter the global and/or local thyroidal state, result in detrimental consequences for brain development and neurological functions that involve alterations in central neurotransmitter systems. Thus, the question as to how TH signaling is implicated in the development and maturation of different neurotransmitter and neuromodulator systems has gained increasing attention. In this review, we first summarize the current knowledge on the regulation of TH signaling components during brain development. We then present recent advances in our understanding on how altered TH signaling compromises the development of cortical glutamatergic neurons, inhibitory GABAergic interneurons, cholinergic and dopaminergic neurons. Thereby, we highlight novel mechanistic insights and point out open questions in this evolving research field.
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Affiliation(s)
| | - Steffen Mayerl
- Department of Endocrinology Diabetes & Metabolism, University Hospital Essen, University of Duisburg-Essen, Hufelandstraße 55, 45147 Essen, Germany
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Custodio RJP, Kim M, Chung YC, Kim BN, Kim HJ, Cheong JH. Thrsp Gene and the ADHD Predominantly Inattentive Presentation. ACS Chem Neurosci 2023; 14:573-589. [PMID: 36716294 DOI: 10.1021/acschemneuro.2c00710] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
There are three presentations of attention-deficit/hyperactivity disorder (ADHD): the predominantly inattention (ADHD-PI), predominantly hyperactive-impulsive (ADHD-HI), and combined (ADHD-C) presentations of ADHD. These may represent distinct childhood-onset neurobehavioral disorders with separate etiologies. ADHD diagnoses are behaviorally based, so investigations into potential etiologies should be founded on behavior. Animal models of ADHD demonstrate face, predictive, and construct validity when they accurately reproduce elements of the symptoms, etiology, biochemistry, and disorder treatment. Spontaneously hypertensive rats (SHR/NCrl) fulfill many validation criteria and compare well with clinical cases of ADHD-C. Compounding the difficulty of selecting an ideal model to study specific presentations of ADHD is a simple fact that our knowledge regarding ADHD neurobiology is insufficient. Accordingly, the current review has explored a potential animal model for a specific presentation, ADHD-PI, with acceptable face, predictive, and construct validity. The Thrsp gene could be a biomarker for ADHD-PI presentation, and THRSP OE mice could represent an animal model for studying this distinct ADHD presentation.
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Affiliation(s)
- Raly James Perez Custodio
- Department of Ergonomics, Leibniz Research Centre for Working Environment and Human Factors─IfADo, Ardeystraße 67, 44139 Dortmund, Germany
| | - Mikyung Kim
- Department of Chemistry & Life Science, Sahmyook University, 815 Hwarang-ro, Nowon-gu, Seoul 01795, Republic of Korea.,Uimyung Research Institute for Neuroscience, Department of Pharmacy, Sahmyook University, 815 Hwarangro, Nowon-gu, Seoul 01795, Republic of Korea
| | - Young-Chul Chung
- Department of Psychiatry, Jeonbuk National University Medical School, 567 Baekje-daero, Deokjin-gu, Jeonju-si, Jeollabuk-do 54896, Republic of Korea
| | - Bung-Nyun Kim
- Department of Psychiatry and Behavioral Science, College of Medicine, Seoul National University, 101 Daehakro, Jongno-gu, Seoul 03080, Republic of Korea
| | - Hee Jin Kim
- Uimyung Research Institute for Neuroscience, Department of Pharmacy, Sahmyook University, 815 Hwarangro, Nowon-gu, Seoul 01795, Republic of Korea
| | - Jae Hoon Cheong
- Institute for New Drug Development, School of Pharmacy, Jeonbuk National University, 567 Baekje-daero, Deokjin-gu, Jeonju-si, Jeollabuk-do 54896, Republic of Korea
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Peedicayil J. The Role of Epigenetics in the Pathogenesis and Potential Treatment of Attention Deficit Hyperactivity Disorder. Curr Neuropharmacol 2022; 20:1642-1650. [PMID: 34544344 PMCID: PMC9881064 DOI: 10.2174/1570159x19666210920091036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Revised: 09/09/2021] [Accepted: 09/14/2021] [Indexed: 11/22/2022] Open
Abstract
There is increasing evidence that dysregulated epigenetic mechanisms of gene expression are involved in the pathogenesis of attention deficit hyperactivity disorder (ADHD). This review presents a comprehensive summary of the current state of research on the role of epigenetics in the pathogenesis of ADHD. The potential role of epigenetic drugs in the treatment of ADHD is also reviewed. Several studies suggest that there are epigenetic abnormalities in preclinical models of ADHD and in ADHD patients. Regarding DNA methylation, many studies have reported DNA hypermethylation. There is evidence that there is increased histone deacetylation in ADHD patients. Abnormalities in the expression of microRNAs (miRNAs) in ADHD patients have also been found. Some currently used drugs for treating ADHD, in addition to their more well-established mechanisms of action, have been shown to alter epigenetic mechanisms of gene expression. Clinical trials of epigenetic drugs in patients with ADHD report favorable results. These data suggest that abnormal epigenetic mechanisms of gene expression may be involved in the pathogenesis of ADHD. Drugs acting on epigenetic mechanisms may be a potential new class of drugs for treating ADHD.
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Affiliation(s)
- Jacob Peedicayil
- Department of Pharmacology and Clinical Pharmacology, Christian Medical College, Vellore, India,Address correspondence to this author at the Department of Pharmacology and Clinical Pharmacology, Christian Medical College, Vellore, India;Tel: 91-0416-2284237; E-mail:
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Epigenetics of Autism Spectrum Disorder: Histone Deacetylases. Biol Psychiatry 2022; 91:922-933. [PMID: 35120709 DOI: 10.1016/j.biopsych.2021.11.021] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Revised: 11/19/2021] [Accepted: 11/22/2021] [Indexed: 01/08/2023]
Abstract
The etiology of autism spectrum disorder (ASD) remains unknown, but gene-environment interactions, mediated through epigenetic mechanisms, are thought to be a key contributing factor. Prenatal environmental factors have been shown to be associated with both increased risk of ASD and altered histone deacetylases (HDACs) or acetylation levels. The relationship between epigenetic changes and gene expression in ASD suggests that alterations in histone acetylation, which lead to changes in gene transcription, may play a key role in ASD. Alterations in the acetylome have been demonstrated for several genes in ASD, including genes involved in synaptic function, neuronal excitability, and immune responses, which are mechanisms previously implicated in ASD. We review preclinical and clinical studies that investigated HDACs and autism-associated behaviors and discuss risk genes for ASD that code for proteins associated with HDACs. HDACs are also implicated in neurodevelopmental disorders with a known genetic etiology, such as 15q11-q13 duplication and Phelan-McDermid syndrome, which share clinical features and diagnostic comorbidities (e.g., epilepsy, anxiety, and intellectual disability) with ASD. Furthermore, we highlight factors that affect the behavioral phenotype of acetylome changes, including sensitive developmental periods and brain region specificity in the context of epigenetic programming.
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Gao Y, Aljazi MB, He J. Kdm6b Haploinsufficiency Causes ASD/ADHD-Like Behavioral Deficits in Mice. Front Behav Neurosci 2022; 16:905783. [PMID: 35711692 PMCID: PMC9194811 DOI: 10.3389/fnbeh.2022.905783] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2022] [Accepted: 05/06/2022] [Indexed: 11/13/2022] Open
Abstract
Autism spectrum disorder (ASD) is a neurodevelopmental disease that has intellectual disability (ID) and attention-deficit/hyperactivity disorder (ADHD) as its common comorbidities. Recent genetic and clinical studies report that KDM6B, a gene encoding a histone H3 lysine 27-specific demethylase, is one of the highest ASD risk genes. However, the relationship between KDM6B mutations and neurodevelopmental diseases remains unclear. Here we use an animal model to show that genetic deletion of one Kdm6b allele in mice leads to autistic-like impaired sociability and object recognition memory. In addition, the mutant mice display markedly increased locomotor activity and impulsivity, two ADHD-like behavioral traits that are ameliorated by methylphenidate treatment. Thus, our study not only uncovers a potential causal link between disruptive KDM6B mutations and ASD/ADHD-like behavioral deficits but also provides a new mouse model for studying the cellular and molecular mechanisms underlying the Kdm6b-mutation-related neurodevelopmental diseases.
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Rahi V, Kumar P. Animal models of attention-deficit hyperactivity disorder (ADHD). Int J Dev Neurosci 2021; 81:107-124. [PMID: 33428802 DOI: 10.1002/jdn.10089] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2020] [Revised: 12/14/2020] [Accepted: 01/06/2021] [Indexed: 12/15/2022] Open
Abstract
Attention-deficit hyperactivity disorder (ADHD) is a heterogeneous neuropsychiatric disorder characterized by three primary symptoms hyperactivity, attention deficit, and impulsiveness, observed in both children and adults. In childhood, this disorder is more common in boys than in girls, and at least 75% will continue to suffer from the disorder until adulthood. Individuals with ADHD generally have poor academic, occupational, and social functioning resulting from developmentally inappropriate levels of hyperactivity and impulsivity, as well as impaired ability to maintain attention on motivationally relevant tasks. Very few drugs available in clinical practice altogether abolish the symptoms of ADHD, therefore, to find new drugs and target it is essential to understand the neuropathological, neurochemical, and genetic alterations that lead to the progression of ADHD. With this contrast, an animal study is the best approach because animal models provide relatively fast invasive manipulation, rigorous hypothesis testing, as well as it provides a better angle to understand the pathological mechanisms involved in disease progression. Moreover, animal models, especially for ADHD, serve with good predictive validity would allow the assessment and development of new therapeutic interventions, with this aim, the present review collect the various animal models on a single platform so that the research can select an appropriate model to pursue his study.
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Affiliation(s)
- Vikrant Rahi
- Department of Pharmaceutical Sciences and Technology, Maharaja Ranjit Singh Punjab Technical University, Bathinda, India
| | - Puneet Kumar
- Department of Pharmaceutical Sciences and Technology, Maharaja Ranjit Singh Punjab Technical University, Bathinda, India
- Department of Pharmacology, Central University of Punjab, Bathinda, India
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Yang Y, Zhan F, Wang YC, Wang B, Shi MX, Guo C, Xu DX, Meng XH. Pubertal fenvalerate exposure impairs cognitive and behavioral development partially through down-regulating hippocampal thyroid hormone receptor signaling. Toxicol Lett 2020; 332:192-201. [PMID: 32693020 DOI: 10.1016/j.toxlet.2020.07.020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Revised: 07/10/2020] [Accepted: 07/17/2020] [Indexed: 12/18/2022]
Abstract
Fenvalerate, a synthetic pyrethroid insecticide, is an environmental endocrine disruptor and neurodevelopmental toxicant. An early report found that pubertal exposure to high-dose fenvalerate impaired cognitive and behavioral development. Here, we aimed to further investigate the effect of pubertal exposure to low-dose fenvalerate on cognitive and behavioral development. Mice were orally administered with fenvalerate (0.2, 1.0 and 5.0 mg/kg) daily from postnatal day (PND) 28 to PND56. Learning and memory were assessed by Morris water maze. Anxiety-related activities were detected by open-field and elevated plus-maze. Increased anxiety activities were observed only in females exposed to fenvalerate. Spatial learning and memory were damaged only in females exposed to fenvalerate. Histopathology observed numerous scattered shrinking neurons and nuclear pyknosis in hippocampal CA1 region. Neuronal density was reduced in hippocampal CA1 region of fenvalerate-exposed mice. Mechanistically, hippocampal thyroid hormone receptor (TR)β1 was down-regulated in a dose-dependent manner in females. In addition, TRα1 was declined only in females exposed to 5.0 mg/kg fenvalerate. Taken together, these suggests that pubertal exposure to low-dose fenvalerate impairs cognitive and behavioral development in a gender-dependent manner. Hippocampal TR signaling may be, at least partially, involved in fenvalerate-induced impairment of cognitive and behavioral development.
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Affiliation(s)
- Yang Yang
- Department of Maternal, Child and Adolescent Health, School of Public Health, Anhui Medical University, Hefei, Anhui, China; Key Laboratory of Population Health Across Life Cycle, Ministry of Education of the People's Republic of China; Anhui Provincial Key Laboratory of Population Health & Aristogenics, Hefei, Anhui, China
| | - Feng Zhan
- Department of Maternal, Child and Adolescent Health, School of Public Health, Anhui Medical University, Hefei, Anhui, China; Key Laboratory of Population Health Across Life Cycle, Ministry of Education of the People's Republic of China; Anhui Provincial Key Laboratory of Population Health & Aristogenics, Hefei, Anhui, China
| | - Ye-Cheng Wang
- Department of Maternal, Child and Adolescent Health, School of Public Health, Anhui Medical University, Hefei, Anhui, China; Key Laboratory of Population Health Across Life Cycle, Ministry of Education of the People's Republic of China; Anhui Provincial Key Laboratory of Population Health & Aristogenics, Hefei, Anhui, China
| | - Bo Wang
- Department of Maternal, Child and Adolescent Health, School of Public Health, Anhui Medical University, Hefei, Anhui, China; Key Laboratory of Population Health Across Life Cycle, Ministry of Education of the People's Republic of China; Anhui Provincial Key Laboratory of Population Health & Aristogenics, Hefei, Anhui, China
| | - Meng-Xing Shi
- Department of Maternal, Child and Adolescent Health, School of Public Health, Anhui Medical University, Hefei, Anhui, China; Key Laboratory of Population Health Across Life Cycle, Ministry of Education of the People's Republic of China; Anhui Provincial Key Laboratory of Population Health & Aristogenics, Hefei, Anhui, China
| | - Ce Guo
- Department of Maternal, Child and Adolescent Health, School of Public Health, Anhui Medical University, Hefei, Anhui, China; Key Laboratory of Population Health Across Life Cycle, Ministry of Education of the People's Republic of China; Anhui Provincial Key Laboratory of Population Health & Aristogenics, Hefei, Anhui, China
| | - De-Xiang Xu
- Department of Maternal, Child and Adolescent Health, School of Public Health, Anhui Medical University, Hefei, Anhui, China; Key Laboratory of Population Health Across Life Cycle, Ministry of Education of the People's Republic of China; Department of Toxicology, School of Public Health, Anhui Medical University, Hefei, Anhui, China.
| | - Xiu-Hong Meng
- Department of Maternal, Child and Adolescent Health, School of Public Health, Anhui Medical University, Hefei, Anhui, China; Key Laboratory of Population Health Across Life Cycle, Ministry of Education of the People's Republic of China; Anhui Provincial Key Laboratory of Population Health & Aristogenics, Hefei, Anhui, China.
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Umezu T, Kita T, Morita M. Hyperactive behavioral phenotypes and an altered brain monoaminergic state in male offspring mice with perinatal hypothyroidism. Toxicol Rep 2019; 6:1031-1039. [PMID: 31673505 PMCID: PMC6816216 DOI: 10.1016/j.toxrep.2019.10.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Revised: 09/20/2019] [Accepted: 10/04/2019] [Indexed: 11/19/2022] Open
Abstract
Thyroid hormone (TH) is essential for normal brain development. TH insufficiency during early stages of development may increase the risk for attention deficit/hyperactivity disorder, in which malfunction of brain monoaminergic systems is likely involved. However, little is known about the effects of perinatal hypothyroidism on behaviors and brain monoaminergic systems in offspring mice. The present study examined in mice (1) whether perinatal hypothyroidism causes hyperactive behavioral phenotypes, (2) how perinatal hypothyroidism influences brain monoaminergic systems, and (3) whether hyperactive behavioral phenotypes are associated with the state of brain monoaminergic systems. When dams were exposed to propylthiouracil, offspring mice developed hypothyroidism during the perinatal period. Offspring mice with perinatal hypothyroidism exhibited hyperactive behavioral phenotypes such as hyper-ambulatory activity and an increased response rate in the two-way active avoidance test in a male-specific manner. Significant decreases in dopamine (DA) and serotonin turnover were observed in the striatum (ST), nucleus accumbens, hypothalamus, and hippocampus in male mice with perinatal hypothyroidism. A significant correlation between ambulatory activity and DA turnover in the ST and an augmented ambulatory response to the DA reuptake inhibitor bupropion suggested that DA in the ST was involved in the hyper-ambulatory activity in mice with perinatal hypothyroidism.
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Affiliation(s)
- Toyoshi Umezu
- Center for Health and Environmental Risk Research, National Institute for Environmental Studies, Tsukuba, Ibaraki 305-8506, Japan
- Corresponding author at: Health Effect Assessment Section, Center for Health and Environmental Risk Research, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki, 305-8506, Japan.
| | - Taizo Kita
- Graduate School of Food and Nutrition, Kyushu Nutrition Welfare University, Kitakyushu, Fukuoka 803-8511, Japan
| | - Masatoshi Morita
- Graduate School of Agriculture, Ehime University, Matsuyama, Ehime 790-8577, Japan
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Gley K, Murani E, Haack F, Trakooljul N, Zebunke M, Puppe B, Wimmers K, Ponsuksili S. Haplotypes of coping behavior associated QTL regions reveal distinct transcript profiles in amygdala and hippocampus. Behav Brain Res 2019; 372:112038. [PMID: 31202863 DOI: 10.1016/j.bbr.2019.112038] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Revised: 06/06/2019] [Accepted: 06/12/2019] [Indexed: 12/15/2022]
Abstract
Stress response and coping behavior in pigs are largely shaped by hypothalamic-pituitary-adrenal axis and sympatho-adrenomedullary system action. However, the dynamic interaction between amygdala and hippocampus crucially modulates the behavioral response towards significant emotional events. While this functional relationship is well documented, the molecular underpinnings still remain insufficiently understood. Our study used transcriptome profiling of porcine amygdala and hippocampus to identify molecular pathways that are differentially activated depending on the haplotype of a significantly coping behavior-associated region on pig chromosome 12 (SSC12). The pigs were classified into two groups based on the haplotype information of this QTL-region discovered in our previous genome-wide association study. Ten each of high- (HR) and low- (LR) reactive pigs (n = 20) were selected for differential gene expression analysis and weighted gene co-expression analysis with subsequent pathway analysis. Differentially expressed genes identified in the amygdala include SELL, CXCR7 and NTS, while TRAF3, PTGS2 and CFI were detected in the hippocampus indicating a role of neuroinflammation and immunological processes. Pathway analysis revealed IL-8 signaling, NF-κB signaling, glutamate and GABA metabolism, glucocorticoid receptor signaling and chemokine signaling in the amygdala and ephrin receptor signaling, as well as NF-κB signaling in the hippocampus. We discovered candidate genes in regions detected by genome-wide association study including ARRB2, ADRBK2, THRB, NEK7 and ACVR2B, which relate to dopaminergic and other monoaminergic neurotransmitter systems, neuroimmunomodulation, neuroinflammation and GABA-ergic neurotransmission. These findings provide insights into the molecular underpinning of divergent coping behavior and associated haplotypes in limbic forebrain system in pig.
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Affiliation(s)
- Kevin Gley
- Leibniz Institute of Farm Animal Biology (FBN), Institute for Genome Biology, Wilhelm-Stahl-Allee 2, D-18196 Dummerstorf, Germany
| | - Eduard Murani
- Leibniz Institute of Farm Animal Biology (FBN), Institute for Genome Biology, Wilhelm-Stahl-Allee 2, D-18196 Dummerstorf, Germany
| | - Fiete Haack
- Leibniz Institute of Farm Animal Biology (FBN), Institute for Genome Biology, Wilhelm-Stahl-Allee 2, D-18196 Dummerstorf, Germany
| | - Nares Trakooljul
- Leibniz Institute of Farm Animal Biology (FBN), Institute for Genome Biology, Wilhelm-Stahl-Allee 2, D-18196 Dummerstorf, Germany
| | - Manuela Zebunke
- Leibniz Institute of Farm Animal Biology (FBN), Institute of Genetics and Biometry, Wilhelm-Stahl-Allee 2, D-18196 Dummerstorf, Germany; Leibniz Institute of Farm Animal Biology (FBN), Institute for Behavioral Physiology, Wilhelm-Stahl-Allee 2, 18196 Dummerstorf, Germany
| | - Birger Puppe
- Leibniz Institute of Farm Animal Biology (FBN), Institute for Behavioral Physiology, Wilhelm-Stahl-Allee 2, 18196 Dummerstorf, Germany
| | - Klaus Wimmers
- Leibniz Institute of Farm Animal Biology (FBN), Institute for Genome Biology, Wilhelm-Stahl-Allee 2, D-18196 Dummerstorf, Germany
| | - Siriluck Ponsuksili
- Leibniz Institute of Farm Animal Biology (FBN), Institute for Genome Biology, Wilhelm-Stahl-Allee 2, D-18196 Dummerstorf, Germany.
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Wang F, Fang M, Hinton DE, Chernick M, Jia S, Zhang Y, Xie L, Dong W, Dong W. Increased coiling frequency linked to apoptosis in the brain and altered thyroid signaling in zebrafish embryos (Danio rerio) exposed to the PBDE metabolite 6-OH-BDE-47. CHEMOSPHERE 2018; 198:342-350. [PMID: 29421749 PMCID: PMC7006228 DOI: 10.1016/j.chemosphere.2018.01.081] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Revised: 01/13/2018] [Accepted: 01/16/2018] [Indexed: 05/04/2023]
Abstract
Polybrominated diphenyl ethers (PBDEs) are a group of brominated flame retardants that are ubiquitously detected in the environment and associated with adverse health outcomes. 6-OH-BDE-47 is a metabolite of the flame retardant, 2,2',4,4'-Tetrabromodiphenyl ether (BDE-47), and there is increasing concern regarding its developmental neurotoxicity and endocrine disrupting properties. In this study, we report that early life exposure in zebrafish (Danio rerio) embryos to 6-OH-BDE-47 (50 and 100 nM) resulted in higher coiling frequency and significantly increased apoptotic cells in the brain. These effects were partially rescued by overexpression of thyroid hormone receptor β (THRβ) mRNA. Moreover, exposure to 100 nM 6-OH-BDE-47 significantly reduced the number of hypothalamic 5-hydroxytryptamine (5-HT, serotonin)-immunoreactive (5-HT-ir) neurons and the mRNA expression of tryptophan hydroxylase 2 (TPH2). These results indicate that 6-OH-BDE-47 affected thyroid hormone regulation through THRβ and negatively impacted the nervous system, in turn, affecting coiling behavior. Correlations of these endpoints suggest that coiling frequency could be used as an indicator of neurotoxicity in embryos.
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Affiliation(s)
- Feng Wang
- Inner Mongolia Key Laboratory of Toxicant Monitoring and Toxicology, Collage of Animal Science and Technology, Inner Mongolia University for Nationalities, Tongliao, Inner Mongolia, 028000, China
| | - Mingliang Fang
- School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore
| | - David E Hinton
- Nicholas School of the Environment, Duke University, Durham, NC, 27708, United States
| | - Melissa Chernick
- Nicholas School of the Environment, Duke University, Durham, NC, 27708, United States
| | - Shenglan Jia
- School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore
| | - Yingdan Zhang
- School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore
| | - Lingtian Xie
- The Environmental Research Institute, MOE Key Laboratory of Theoretical Chemistry of Environment, South China Normal University, Guangzhou, Guangdong, 510006, China
| | - Wenjing Dong
- Inner Mongolia Key Laboratory of Toxicant Monitoring and Toxicology, Collage of Animal Science and Technology, Inner Mongolia University for Nationalities, Tongliao, Inner Mongolia, 028000, China
| | - Wu Dong
- Inner Mongolia Key Laboratory of Toxicant Monitoring and Toxicology, Collage of Animal Science and Technology, Inner Mongolia University for Nationalities, Tongliao, Inner Mongolia, 028000, China; Nicholas School of the Environment, Duke University, Durham, NC, 27708, United States.
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