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Chen T, Dai K, Wu H. Persistent organic pollutants exposure and risk of depression: A systematic review and meta-analysis. ENVIRONMENTAL RESEARCH 2024; 263:120160. [PMID: 39414105 DOI: 10.1016/j.envres.2024.120160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2024] [Revised: 10/13/2024] [Accepted: 10/14/2024] [Indexed: 10/18/2024]
Abstract
Recently, more and more epidemiological studies have examined the impact of exposure to persistent organic pollutants (POPs) on depression, but the results are inconsistent. Thus, we conducted a systematic review and meta-analysis to better understand the effects of POPs exposure on the risk of depression in the general population. We searched PubMed, Embase, Web of Science, and Scopus databases for studies before March 20, 2024. Random-effects meta-analysis was applied to calculate pooled relative risk (OR) and 95% confidence intervals (CIs). We also assessed potential heterogeneity and publication bias across studies and conducted sensitivity analysis. A total of 26 studies were included, and the results indicated that exposure to ΣPBDEs, PBDE-47, and PBDE-99 increased the risk of depression, with OR of 1.37 (95 % CI = 1.06-1.79), 1.30 (95% CI = 1.08-1.56), 1.46 (95 % CI = 1.00-2.12) respectively. On the contrary, the exposure assessment results of PFOS showed a negative correlation with the risk of depression. There is no association between exposure to ΣPFAS, ΣPCBs, and ΣOCPs and increased risk of depression. More standardized studies and more samples are needed in the future to confirm the findings of this study. This finding could provide theoretical references for the prevention and management of depression and offer insights for the risk assessment of POPs exposure.
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Affiliation(s)
- Tao Chen
- Policy Research Center for Environment and Economy, Ministry of Ecology and Environment of the People's Republic of China, 100029, Beijing, China
| | - Kexin Dai
- Department of Nutrition, Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA
| | - Huihui Wu
- Chinese Academy of Environmental Planning, 100041, Beijing, China.
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2
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Hilz EN, Schnurer C, Bhamidipati S, Deka J, Thompson LM, Gore AC. Cognitive effects of early life exposure to PCBs: Sex-specific behavioral, hormonal and neuromolecular mechanisms involving the brain dopamine system. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.09.13.612971. [PMID: 39314290 PMCID: PMC11419158 DOI: 10.1101/2024.09.13.612971] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/25/2024]
Abstract
Endocrine-disrupting chemicals (EDCs) are environmental toxicants that disrupt hormonal and neurodevelopmental processes. Among these chemicals, polychlorinated biphenyls (PCBs) are particularly concerning due to their resistance to biodegradation and tendency to bioaccumulate. PCBs affect neurodevelopmental function and disrupt the brain's dopamine (DA) system, which is crucial for attentional, affective, and reward processing. These disruptions may contribute to the rising prevalence of DA-mediated neuropsychiatric disorders such as ADHD, depression, and substance use disorders. Notably, these behaviors are sexually dimorphic, in part due to differences in sex hormones and their receptors, which are targets of estrogenic PCBs. Therefore, this study determined effects of early life PCB exposure on behaviors and neurochemistry related to potential disruption of dopaminergic signaling. Male and female Sprague Dawley rats were exposed to PCBs or vehicle perinatally and then underwent a series of behavioral tests, including the sucrose preference test to measure affect, conditioned orienting to assess incentive-motivational phenotype, and attentional set-shifting to evaluate cognitive flexibility and response latency. Following these tests, rats were euthanized, and we measured serum estradiol (E2), midbrain DA cells, and gene expression in the midbrain. Female rats exposed perinatally to A1221 exhibited decreased sucrose preference, and both male and female A1221 rats had reduced response latency in the attentional set-shifting task compared to vehicle counterparts. Conditioned orienting, serum estradiol (E2), and midbrain DA cell numbers were not affected in either sex; however, A1221-exposed male rats displayed higher expression of estrogen receptor alpha ( Esr1 ) in the midbrain and non-significant effects on other DA-signaling genes. Additionally, E2 uniquely predicted behavioral outcomes and DAergic cell numbers in A1221-exposed female rats, whereas DA signaling genes were predictive of behavioral outcomes in males. These data highlight sex-specific effects of A1221 on neuromolecular and behavioral phenotypes.
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Currim F, Tanwar R, Brown-Leung JM, Paranjape N, Liu J, Sanders LH, Doorn JA, Cannon JR. Selective dopaminergic neurotoxicity modulated by inherent cell-type specific neurobiology. Neurotoxicology 2024; 103:266-287. [PMID: 38964509 PMCID: PMC11288778 DOI: 10.1016/j.neuro.2024.06.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2024] [Revised: 06/27/2024] [Accepted: 06/28/2024] [Indexed: 07/06/2024]
Abstract
Parkinson's disease (PD) is a debilitating neurodegenerative disease affecting millions of individuals worldwide. Hallmark features of PD pathology are the formation of Lewy bodies in neuromelanin-containing dopaminergic (DAergic) neurons of the substantia nigra pars compacta (SNpc), and the subsequent irreversible death of these neurons. Although genetic risk factors have been identified, around 90 % of PD cases are sporadic and likely caused by environmental exposures and gene-environment interaction. Mechanistic studies have identified a variety of chemical PD risk factors. PD neuropathology occurs throughout the brain and peripheral nervous system, but it is the loss of DAergic neurons in the SNpc that produce many of the cardinal motor symptoms. Toxicology studies have found specifically the DAergic neuron population of the SNpc exhibit heightened sensitivity to highly variable chemical insults (both in terms of chemical structure and mechanism of neurotoxic action). Thus, it has become clear that the inherent neurobiology of nigral DAergic neurons likely underlies much of this neurotoxic response to broad insults. This review focuses on inherent neurobiology of nigral DAergic neurons and how such neurobiology impacts the primary mechanism of neurotoxicity. While interactions with a variety of other cell types are important in disease pathogenesis, understanding how inherent DAergic biology contributes to selective sensitivity and primary mechanisms of neurotoxicity is critical to advancing the field. Specifically, key biological features of DAergic neurons that increase neurotoxicant susceptibility.
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Affiliation(s)
- Fatema Currim
- School of Health Sciences, Purdue University, West Lafayette, IN 47901, USA; Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN 47901, USA
| | - Reeya Tanwar
- School of Health Sciences, Purdue University, West Lafayette, IN 47901, USA; Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN 47901, USA
| | - Josephine M Brown-Leung
- School of Health Sciences, Purdue University, West Lafayette, IN 47901, USA; Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN 47901, USA
| | - Neha Paranjape
- Pharmaceutical Sciences and Experimental Therapeutics, College of Pharmacy, University of Iowa, Iowa City, IA 52242, USA
| | - Jennifer Liu
- Departments of Neurology and Pathology, Duke University School of Medicine, Durham, NC 27710, USA; Duke Center for Neurodegeneration and Neurotherapeutics, Duke University School of Medicine, Durham, NC 27710, USA
| | - Laurie H Sanders
- Departments of Neurology and Pathology, Duke University School of Medicine, Durham, NC 27710, USA; Duke Center for Neurodegeneration and Neurotherapeutics, Duke University School of Medicine, Durham, NC 27710, USA
| | - Jonathan A Doorn
- Pharmaceutical Sciences and Experimental Therapeutics, College of Pharmacy, University of Iowa, Iowa City, IA 52242, USA
| | - Jason R Cannon
- School of Health Sciences, Purdue University, West Lafayette, IN 47901, USA; Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN 47901, USA.
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4
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Bucher ML, Dicent J, Duarte Hospital C, Miller GW. Neurotoxicology of dopamine: Victim or assailant? Neurotoxicology 2024; 103:175-188. [PMID: 38857676 DOI: 10.1016/j.neuro.2024.06.001] [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: 04/13/2024] [Revised: 06/02/2024] [Accepted: 06/03/2024] [Indexed: 06/12/2024]
Abstract
Since the identification of dopamine as a neurotransmitter in the mid-20th century, investigators have examined the regulation of dopamine homeostasis at a basic biological level and in human disorders. Genetic animal models that manipulate the expression of proteins involved in dopamine homeostasis have provided key insight into the consequences of dysregulated dopamine. As a result, we have come to understand the potential of dopamine to act as an endogenous neurotoxin through the generation of reactive oxygen species and reactive metabolites that can damage cellular macromolecules. Endogenous factors, such as genetic variation and subcellular processes, and exogenous factors, such as environmental exposures, have been identified as contributors to the dysregulation of dopamine homeostasis. Given the variety of dysregulating factors that impact dopamine homeostasis and the potential for dopamine itself to contribute to further cellular dysfunction, dopamine can be viewed as both the victim and an assailant of neurotoxicity. Parkinson's disease has emerged as the exemplar case study of dopamine dysregulation due to the genetic and environmental factors known to contribute to disease risk, and due to the evidence of dysregulated dopamine as a pathologic and pathogenic feature of the disease. This review, inspired by the talk, "Dopamine in Durham: location, location, location" presented by Dr. Miller for the Jacob Hooisma Memorial Lecture at the International Neurotoxicology Association meeting in 2023, offers a primer on dopamine toxicity covering endogenous and exogenous factors that disrupt dopamine homeostasis and the actions of dopamine as an endogenous neurotoxin.
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Affiliation(s)
- Meghan L Bucher
- Department of Environmental Health Sciences, Mailman School of Public Health at Columbia University, New York, NY 10032, USA
| | - Jocelyn Dicent
- Department of Environmental Health Sciences, Mailman School of Public Health at Columbia University, New York, NY 10032, USA
| | - Carolina Duarte Hospital
- Department of Environmental Health Sciences, Mailman School of Public Health at Columbia University, New York, NY 10032, USA
| | - Gary W Miller
- Department of Environmental Health Sciences, Mailman School of Public Health at Columbia University, New York, NY 10032, USA; Department of Molecular Pharmacology and Therapeutics, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA.
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5
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Krauskopf J, Eggermont K, Caiment F, Verfaillie C, de Kok TM. Molecular insights into PCB neurotoxicity: Comparing transcriptomic responses across dopaminergic neurons, population blood cells, and Parkinson's disease pathology. ENVIRONMENT INTERNATIONAL 2024; 186:108642. [PMID: 38608384 DOI: 10.1016/j.envint.2024.108642] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2024] [Revised: 03/26/2024] [Accepted: 04/08/2024] [Indexed: 04/14/2024]
Abstract
Parkinson's disease (PD) is a complex neurodegenerative disorder influenced by genetic factors and environmental exposures. Polychlorinated biphenyls (PCBs), a group of synthetic organic compounds, have been identified as potential environmental risk factors for neurodegenerative diseases, including PD. We explored PCB-induced neurotoxicity mechanisms using iPSC-derived dopaminergic neurons and assessed their transcriptomic responses to varying PCB concentrations (0.01 μM, 0.5 μM, and 10 μM). Specifically, we focused on PCB-180, a congener known for its accumulation in human brains. The exposure durations were 24 h and 74 h, allowing us to capture both short-term and more prolonged effects on gene expression patterns. We observed that PCB exposure led to the suppression of oxidative phosphorylation, synaptic function, and neurotransmitter release, implicating these pathways in PCB-induced neurotoxicity. In our comparative analysis, we noted similarities in PCB-induced changes with other PD-related compounds like MPP+ and rotenone. Our findings also aligned with gene expression changes in human blood derived from a population exposed to PCBs, highlighting broader inflammatory responses. Additionally, molecular patterns seen in iPSC-derived neurons were confirmed in postmortem PD brain tissues, validating our in vitro results. In conclusion, our study offers novel insights into the multifaceted impacts of PCB-induced perturbations on various cellular contexts relevant to PD. The use of iPSC-derived dopaminergic neurons allowed us to decipher intricate transcriptomic alterations, bridging the gap between in vitro and in vivo findings. This work underscores the potential role of PCB exposure in neurodegenerative diseases like PD, emphasizing the need to consider both systemic and cell specific effects.
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Affiliation(s)
- Julian Krauskopf
- Maastricht University, Universiteitssingel 50, 6229 ER Maastricht, The Netherlands; MHeNS, School for Mental Health and Neuroscience, Maastricht University, Universiteitssingel 50, 6229 ER Maastricht, The Netherlands. %
| | - Kristel Eggermont
- Stem Cell Institute, Department of Development and Regeneration, Katholieke Universiteit Leuven, Herestraat 49, 3000 Leuven, Belgium
| | - Florian Caiment
- Maastricht University, Universiteitssingel 50, 6229 ER Maastricht, The Netherlands
| | - Catherine Verfaillie
- Stem Cell Institute, Department of Development and Regeneration, Katholieke Universiteit Leuven, Herestraat 49, 3000 Leuven, Belgium
| | - Theo M de Kok
- Maastricht University, Universiteitssingel 50, 6229 ER Maastricht, The Netherlands; MHeNS, School for Mental Health and Neuroscience, Maastricht University, Universiteitssingel 50, 6229 ER Maastricht, The Netherlands
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6
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Dorsey ER, De Miranda BR, Horsager J, Borghammer P. The Body, the Brain, the Environment, and Parkinson's Disease. JOURNAL OF PARKINSON'S DISEASE 2024; 14:363-381. [PMID: 38607765 DOI: 10.3233/jpd-240019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/14/2024]
Abstract
The brain- and body-first models of Lewy body disorders predict that aggregated alpha-synuclein pathology usually begins in either the olfactory system or the enteric nervous system. In both scenarios the pathology seems to arise in structures that are closely connected to the outside world. Environmental toxicants, including certain pesticides, industrial chemicals, and air pollution are therefore plausible trigger mechanisms for Parkinson's disease and dementia with Lewy bodies. Here, we propose that toxicants inhaled through the nose can lead to pathological changes in alpha-synuclein in the olfactory system that subsequently spread and give rise to a brain-first subtype of Lewy body disease. Similarly, ingested toxicants can pass through the gut and cause alpha-synuclein pathology that then extends via parasympathetic and sympathetic pathways to ultimately produce a body-first subtype. The resulting spread can be tracked by the development of symptoms, clinical assessments, in vivo imaging, and ultimately pathological examination. The integration of environmental exposures into the brain-first and body-first models generates testable hypotheses, including on the prevalence of the clinical conditions, their future incidence, imaging patterns, and pathological signatures. The proposed link, though, has limitations and leaves many questions unanswered, such as the role of the skin, the influence of the microbiome, and the effects of ongoing exposures. Despite these limitations, the interaction of exogenous factors with the nose and the gut may explain many of the mysteries of Parkinson's disease and open the door toward the ultimate goal -prevention.
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Affiliation(s)
- E Ray Dorsey
- Department of Neurology and Center for Health and Technology, University of Rochester Medical Center, Rochester, NY, USA
| | - Briana R De Miranda
- Department of Neurology, Center for Neurodegeneration and Experimental Therapeutics, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Jacob Horsager
- Department of Nuclear Medicine and PET, Aarhus University Hospital, Aarhus, Denmark
| | - Per Borghammer
- Department of Nuclear Medicine and PET, Aarhus University Hospital, Aarhus, Denmark
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Bullert A, Li X, Chunyun Z, Lee K, Pulliam CF, Cagle BS, Doorn JA, Klingelhutz AJ, Robertson LW, Lehmler HJ. Disposition and metabolomic effects of 2,2',5,5'-tetrachlorobiphenyl in female rats following intraperitoneal exposure. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2023; 102:104245. [PMID: 37572994 PMCID: PMC10562985 DOI: 10.1016/j.etap.2023.104245] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 08/07/2023] [Accepted: 08/09/2023] [Indexed: 08/14/2023]
Abstract
The disposition and toxicity of lower chlorinated PCBs (LC-PCBs) with less than five chlorine substituents have received little attention. This study characterizes the distribution and metabolomic effects of PCB 52, an LC-PCB found in indoor and outdoor air, three weeks after intraperitoneal exposure of female Sprague Dawley rats to 0, 1, 10, or 100 mg/kg BW. PCB 52 exposure did not affect overall body weight. Gas chromatography-tandem mass spectrometry (GC-MS/MS) analysis identified PCB 52 in all tissues investigated. Hydroxylated, sulfated, and methylated PCB metabolites, identified using GC-MS/MS and nontarget liquid chromatography-high resolution mass spectrometry (Nt-LCMS), were primarily found in the serum and liver of rats exposed to 100 mg/kg BW. Metabolomic analysis revealed minor effects on L-cysteine, glycine, cytosine, sphingosine, thymine, linoleic acid, orotic acid, L-histidine, and erythrose serum levels. Thus, the metabolism of PCB 52 and its effects on the metabolome must be considered in toxicity studies.
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Affiliation(s)
- Amanda Bullert
- Department of Occupational and Environmental Health, College of Public Health, University of Iowa, Iowa City, IA 52242, USA; Interdisciplinary Graduate Program in Neuroscience, University of Iowa, Iowa City, IA 52242, USA
| | - Xueshu Li
- Department of Occupational and Environmental Health, College of Public Health, University of Iowa, Iowa City, IA 52242, USA
| | - Zhang Chunyun
- Department of Occupational and Environmental Health, College of Public Health, University of Iowa, Iowa City, IA 52242, USA
| | - Kendra Lee
- Department of Occupational and Environmental Health, College of Public Health, University of Iowa, Iowa City, IA 52242, USA
| | - Casey F Pulliam
- Interdisciplinary Graduate Program in Human Toxicology, University of Iowa, Iowa City, IA 52242, USA
| | - Brianna S Cagle
- Department of Pharmaceutical Sciences and Experimental Therapeutics, University of Iowa, Iowa City, IA 52242, USA
| | - Jonathan A Doorn
- Interdisciplinary Graduate Program in Neuroscience, University of Iowa, Iowa City, IA 52242, USA; Interdisciplinary Graduate Program in Human Toxicology, University of Iowa, Iowa City, IA 52242, USA; Department of Pharmaceutical Sciences and Experimental Therapeutics, University of Iowa, Iowa City, IA 52242, USA
| | - Aloysius J Klingelhutz
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
| | - Larry W Robertson
- Department of Occupational and Environmental Health, College of Public Health, University of Iowa, Iowa City, IA 52242, USA; Interdisciplinary Graduate Program in Human Toxicology, University of Iowa, Iowa City, IA 52242, USA
| | - Hans-Joachim Lehmler
- Department of Occupational and Environmental Health, College of Public Health, University of Iowa, Iowa City, IA 52242, USA; Interdisciplinary Graduate Program in Neuroscience, University of Iowa, Iowa City, IA 52242, USA; Interdisciplinary Graduate Program in Human Toxicology, University of Iowa, Iowa City, IA 52242, USA.
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8
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Bullert A, Li X, Zhang C, Lee K, Pulliam CF, Cagle BS, Doorn JA, Klingelhutz AJ, Robertson LW, Lehmler HJ. Disposition and Metabolomic Effects of 2,2',5,5'-Tetrachlorobiphenyl in Female Rats Following Intraperitoneal Exposure. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.19.544952. [PMID: 37609242 PMCID: PMC10441371 DOI: 10.1101/2023.06.19.544952] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 08/24/2023]
Abstract
The disposition and toxicity of lower chlorinated PCBs (LC-PCBs) with less than five chlorine substituents have received little attention. This study characterizes the distribution and metabolomic effects of PCB 52, an LC-PCB found in indoor and outdoor air, three weeks after intraperitoneal exposure of female Sprague Dawley rats to 0, 1, 10, or 100 mg/kg BW. PCB 52 exposure did not affect overall body weight. Gas chromatography-tandem mass spectrometry (GC-MS/MS) analysis identified PCB 52 in all tissues investigated. Hydroxylated, sulfated, and methylated PCB metabolites, identified using GC-MS/MS and nontarget liquid chromatography-high resolution mass spectrometry (Nt-LCMS), were primarily found in the serum and liver of rats exposed to 100 mg/kg BW. Metabolomic analysis revealed minor effects on L-cysteine, glycine, cytosine, sphingosine, thymine, linoleic acid, orotic acid, L-histidine, and erythrose serum levels. Thus, the metabolism of PCB 52 and its effects on the metabolome must be considered in toxicity studies. Highlights PCB 52 was present in adipose, brain, liver, and serum 3 weeks after PCB exposureLiver and serum contained hydroxylated, sulfated, and methylated PCB 52 metabolitesMetabolomics analysis revealed minor changes in endogenous serum metabolitesLevels of dopamine and its metabolites in the brain were not affected by PCB 52.
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Affiliation(s)
- Amanda Bullert
- Department of Occupational and Environmental Health, College of Public Health, University of Iowa, Iowa City, IA 52242, USA
- Interdisciplinary Graduate Program in Neuroscience, University of Iowa, Iowa City, IA 52242, USA
| | - Xueshu Li
- Department of Occupational and Environmental Health, College of Public Health, University of Iowa, Iowa City, IA 52242, USA
| | - Chunyun Zhang
- Department of Occupational and Environmental Health, College of Public Health, University of Iowa, Iowa City, IA 52242, USA
| | - Kendra Lee
- Department of Occupational and Environmental Health, College of Public Health, University of Iowa, Iowa City, IA 52242, USA
| | - Casey F. Pulliam
- Interdisciplinary Program in Human Toxicology, University of Iowa, Iowa City, IA 52242, USA
| | - Brianna S. Cagle
- Department of Pharmaceutical Sciences and Experimental Therapeutics, University of Iowa, Iowa City, IA 52242, USA
| | - Jonathan A. Doorn
- Interdisciplinary Graduate Program in Neuroscience, University of Iowa, Iowa City, IA 52242, USA
- Interdisciplinary Program in Human Toxicology, University of Iowa, Iowa City, IA 52242, USA
- Department of Pharmaceutical Sciences and Experimental Therapeutics, University of Iowa, Iowa City, IA 52242, USA
| | - Aloysius J. Klingelhutz
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
| | - Larry W. Robertson
- Department of Occupational and Environmental Health, College of Public Health, University of Iowa, Iowa City, IA 52242, USA
- Interdisciplinary Program in Human Toxicology, University of Iowa, Iowa City, IA 52242, USA
| | - Hans-Joachim Lehmler
- Department of Occupational and Environmental Health, College of Public Health, University of Iowa, Iowa City, IA 52242, USA
- Interdisciplinary Graduate Program in Neuroscience, University of Iowa, Iowa City, IA 52242, USA
- Interdisciplinary Program in Human Toxicology, University of Iowa, Iowa City, IA 52242, USA
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9
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Hilz EN, Lee HJ. Estradiol and progesterone in female reward-learning, addiction, and therapeutic interventions. Front Neuroendocrinol 2023; 68:101043. [PMID: 36356909 DOI: 10.1016/j.yfrne.2022.101043] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Revised: 09/24/2022] [Accepted: 10/28/2022] [Indexed: 11/09/2022]
Abstract
Sex steroid hormones like estradiol (E2) and progesterone (P4) guide the sexual organization and activation of the developing brain and control female reproductive behavior throughout the lifecycle; importantly, these hormones modulate functional activity of not just the endocrine system, but most of the nervous system including the brain reward system. The effects of E2 and P4 can be seen in the processing of and memory for rewarding stimuli and in the development of compulsive reward-seeking behaviors like those seen in substance use disorders. Women are at increased risk of developing substance use disorders; however, the origins of this sex difference are not well understood and therapeutic interventions targeting ovarian hormones have produced conflicting results. This article reviews the contribution of the E2 and P4 in females to functional modulation of the brain reward system, their possible roles in origins of addiction vulnerability, and the development and treatment of compulsive reward-seeking behaviors.
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Affiliation(s)
- Emily N Hilz
- The University of Texas at Austin, Department of Pharmacology, USA.
| | - Hongjoo J Lee
- The University of Texas at Austin, Department of Psychology, USA; The University of Texas at Austin, Institute for Neuroscience, USA
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10
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Rajendran R, Ragavan RP, Al-Sehemi AG, Uddin MS, Aleya L, Mathew B. Current understandings and perspectives of petroleum hydrocarbons in Alzheimer's disease and Parkinson's disease: a global concern. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:10928-10949. [PMID: 35000177 DOI: 10.1007/s11356-021-17931-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Accepted: 11/30/2021] [Indexed: 06/14/2023]
Abstract
Over the last few decades, the global prevalence of neurodevelopmental and neurodegenerative illnesses has risen rapidly. Although the aetiology remains unclear, evidence is mounting that exposure to persistent hydrocarbon pollutants is a substantial risk factor, predisposing a person to neurological diseases later in life. Epidemiological studies correlate environmental hydrocarbon exposure to brain disorders including neuropathies, cognitive, motor and sensory impairments; neurodevelopmental disorders like autism spectrum disorder (ASD); and neurodegenerative disorders like Alzheimer's disease (AD) and Parkinson's disease (PD). Particulate matter, benzene, toluene, ethylbenzene, xylenes, polycyclic aromatic hydrocarbons and endocrine-disrupting chemicals have all been linked to neurodevelopmental problems in all class of people. There is mounting evidence that supports the prevalence of petroleum hydrocarbon becoming neurotoxic and being involved in the pathogenesis of AD and PD. More study is needed to fully comprehend the scope of these problems in the context of unconventional oil and natural gas. This review summarises in vitro, animal and epidemiological research on the genesis of neurodegenerative disorders, highlighting evidence that supports inexorable role of hazardous hydrocarbon exposure in the pathophysiology of AD and PD. In this review, we offer a summary of the existing evidence gathered through a Medline literature search of systematic reviews and meta-analyses of the most important epidemiological studies published so far.
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Affiliation(s)
- Rajalakshmi Rajendran
- Department of Pharmacy Practice, Amrita School of Pharmacy, Amrita Vishwa Vidyapeetham, Kochi, 682041, Kerala, India
| | - Roshni Pushpa Ragavan
- Research Center for Advanced Materials Science, King Khalid University, Abha, 61413, Saudi Arabia.
| | - Abdullah G Al-Sehemi
- Research Center for Advanced Materials Science, King Khalid University, Abha, 61413, Saudi Arabia
- Department of Chemistry, King Khalid University, Abha, 61413, Saudi Arabia
| | - Md Sahab Uddin
- Department of Pharmacy, Southeast University, Dhaka, Bangladesh
- Pharmakon Neuroscience Research Network, Dhaka, Bangladesh
| | - Lotfi Aleya
- Laboratoire Chrono-Environment, CNRS6249, Universite de Bourgogne Franche-Comte, Besancon, France
| | - Bijo Mathew
- Department of Pharmaceutical Chemistry, Amrita School of Pharmacy, Amrita Vishwa Vidyapeetham, AIMS Health Sciences Campus, Kochi, 682 041, India.
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11
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Johnson AM, Ou ZYA, Gordon R, Saminathan H. Environmental neurotoxicants and inflammasome activation in Parkinson's disease - A focus on the gut-brain axis. Int J Biochem Cell Biol 2022; 142:106113. [PMID: 34737076 DOI: 10.1016/j.biocel.2021.106113] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2021] [Revised: 10/25/2021] [Accepted: 10/29/2021] [Indexed: 12/26/2022]
Abstract
Inflammasomes are multi-protein complexes expressed in immune cells that function as intracellular sensors of environmental, metabolic and cellular stress. Inflammasome activation in the brain, has been shown to drive neuropathology and disease progression by multiple mechanisms, making it one of the most attractive therapeutic targets for disease modification in Parkinson's Disease (PD). Extensive inflammasome activation is evident in the brains of people with PD at the sites of dopaminergic degeneration and synuclein aggregation. While substantial progress has been made on validating inflammasome activation as a therapeutic target for PD, the mechanisms by which inflammasome activation is triggered and sustained over the disease course remain poorly understood. A growing body of evidence point to environmental and occupational chemical exposures as possible triggers of inflammasome activation in PD. The involvement of the gastrointestinal system and gut microbiota in PD pathophysiology is beginning to be elucidated, especially the profound link between gut dysbiosis and immune activation. While large cohort studies confirmed specific changes in the gut microbiota in PD patients compared to age-matched healthy controls, recent research suggest that synuclein pathology could be initiated in the gastrointestinal tract. In this review, we present a summarized perspective on current understanding on inflammasome activation and the gut-brain-axis link during PD pathophysiology. We discuss multiple environmental toxicants that are implicated as the etiological agents in causing idiopathic PD and their mechanistic underpinnings during neuroinflammatory events. We additionally present future directions that needs to address the research questions related to the gut-microbiome-brain mechanisms in PD.
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Affiliation(s)
- Aishwarya M Johnson
- Department of Veterinary Medicine, College of Food and Agriculture, United Arab Emirates University, Al Ain, UAE
| | - Zhen-Yi Andy Ou
- Translational Neuroscience Laboratory, UQ Centre for Clinical Research, The University of Queensland, Australia; School of Biomedical Sciences, University of Queensland, Australia
| | - Richard Gordon
- Translational Neuroscience Laboratory, UQ Centre for Clinical Research, The University of Queensland, Australia; School of Biomedical Sciences, University of Queensland, Australia
| | - Hariharan Saminathan
- Department of Veterinary Medicine, College of Food and Agriculture, United Arab Emirates University, Al Ain, UAE.
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12
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Regan SL, Williams MT, Vorhees CV. Review of rodent models of attention deficit hyperactivity disorder. Neurosci Biobehav Rev 2022; 132:621-637. [PMID: 34848247 PMCID: PMC8816876 DOI: 10.1016/j.neubiorev.2021.11.041] [Citation(s) in RCA: 34] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 11/22/2021] [Accepted: 11/23/2021] [Indexed: 01/03/2023]
Abstract
Attention deficit hyperactivity disorder (ADHD) is a polygenic neurodevelopmental disorder that affects 8-12 % of children and >4 % of adults. Environmental factors are believed to interact with genetic predispositions to increase susceptibility to ADHD. No existing rodent model captures all aspects of ADHD, but several show promise. The main genetic models are the spontaneous hypertensive rat, dopamine transporter knock-out (KO) mice, dopamine receptor subtype KO mice, Snap-25 KO mice, guanylyl cyclase-c KO mice, and latrophilin-3 KO mice and rats. Environmental factors thought to contribute to ADHD include ethanol, nicotine, PCBs, lead (Pb), ionizing irradiation, 6-hydroxydopamine, neonatal hypoxia, some pesticides, and organic pollutants. Model validation criteria are outlined, and current genetic models evaluated against these criteria. Future research should explore induced multiple gene KOs given that ADHD is polygenic and epigenetic contributions. Furthermore, genetic models should be combined with environmental agents to test for interactions.
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Affiliation(s)
- Samantha L. Regan
- Neuroscience Graduate Program, University of Cincinnati, Cincinnati, OH 45229
| | - Michael T. Williams
- Department of Pediatrics, University of Cincinnati College of Medicine, and Division of Neurology, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229
| | - Charles V. Vorhees
- Department of Pediatrics, University of Cincinnati College of Medicine, and Division of Neurology, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229,Corresponding author: Charles V. Vorhees, Ph.D., Div. of Neurology, Cincinnati Children’s Hospital Medical Center, 3333 Burnet Ave., Cincinnati, OH 45229, USA:
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13
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Lisek M, Boczek T, Stragierowicz J, Wawrzyniak J, Guo F, Klimczak M, Kilanowicz A, Zylinska L. Hexachloronaphthalene (HxCN) impairs the dopamine pathway in an in vitro model of PC12 cells. CHEMOSPHERE 2022; 287:132284. [PMID: 34563782 DOI: 10.1016/j.chemosphere.2021.132284] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Revised: 09/07/2021] [Accepted: 09/16/2021] [Indexed: 06/13/2023]
Abstract
Among polychlorinated naphthalenes (PCNs), listed by the Stockholm convention as Persistent Organic Pollutants (POPs), hexachloronaphthalenes are considered the most toxic and raise the highest concern. Of these, 1,2,3,5,6,7-hexachloronaphthalanene (PCN67) is considered the main congener affecting human health due to its hepatotoxicity and its ability to disturb the reproductive, endocrine, and hematological systems. It is also prevalent in human serum/plasma, milk, and adipose tissue. However, little is known about its neurotoxicity, despite the fact that anorectic effects have been observed in workers occupationally exposed to PCNs and in animal research on PCN67. Since dopamine is involved in many aspects of food intake, the aim of this study was to confirm whether PCN67 affects dopamine synthesis in differentiated PC12 cells, a widely used model of neurosecretion. Our results show that exposure to PCN67 resulted in diminished dopamine content and release. Moreover, PCN67 also affected the expression of tyrosine hydroxylase and lowered the expression of vesicular monoamine transporter 1 (VMAT1). In addition, significantly lower expression of antioxidant enzymes, including catalase, glutathione peroxidase and copper/zinc superoxide dismutase, was observed in comparison to the vehicle. In conclusion, PCN67 appears to disturb dopaminergic transmission by altering tyrosine hydroxylation, reducing VMAT1 expression and impairing antioxidant protection. Our study provides a potential mechanism for how PCN67 may cause dopamine deficiency and contribute to neuronal death by affecting cellular antioxidant potency; however, this conclusion requires further research.
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Affiliation(s)
- Malwina Lisek
- Department of Molecular Neurochemistry, Medical University of Lodz, 92-215, Lodz, Poland.
| | - Tomasz Boczek
- Department of Molecular Neurochemistry, Medical University of Lodz, 92-215, Lodz, Poland.
| | | | - Julia Wawrzyniak
- Department of Molecular Neurochemistry, Medical University of Lodz, 92-215, Lodz, Poland.
| | - Feng Guo
- Department of Pharmaceutical Toxicology, China Medical University, Shenyang, 110122, Liaoning province, China.
| | - Michał Klimczak
- Department of Toxicology, Medical University of Lodz, 90-151, Lodz, Poland.
| | - Anna Kilanowicz
- Department of Toxicology, Medical University of Lodz, 90-151, Lodz, Poland.
| | - Ludmila Zylinska
- Department of Molecular Neurochemistry, Medical University of Lodz, 92-215, Lodz, Poland.
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14
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Ayala-Lopez N, Watts SW. Physiology and Pharmacology of Neurotransmitter Transporters. Compr Physiol 2021; 11:2279-2295. [PMID: 34190339 DOI: 10.1002/cphy.c200035] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Regulation of the ability of a neurotransmitter [our focus: serotonin, norepinephrine, dopamine, acetylcholine, glycine, and gamma-aminobutyric acid (GABA)] to reach its receptor targets is regulated in part by controlling the access the neurotransmitter has to receptors. Transporters, located at both the cellular plasma membrane and in subcellular vesicles, carry a myriad of responsibilities that include enabling neurotransmitter release and controlling uptake of neurotransmitter back into a cell or vesicle. Driven largely by electrochemical gradients, these transporters move neurotransmitters. The regulation of the transporters themselves through changes in expression and/or posttranslational modification allows for fine-tuning of this system. Transporters have been best recognized as targets for psychoactive stimulants and remain a mainstay target of primarily central nervous system (CNS) acting drugs for treatment of debilitating diseases such as depression and anxiety. Studies reveal, however, that transporters are found and functional in tissues outside the CNS (gastrointestinal and cardiovascular tissues, for example). The importance of neurotransmitter transporters is underscored with discoveries that dysfunction of transporters can cause life-changing disease. This article provides a high-level review of major classes of both plasma membrane transporters and vesicular transporters. © 2021 American Physiological Society. Compr Physiol 11:2279-2295, 2021.
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Affiliation(s)
- Nadia Ayala-Lopez
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Stephanie W Watts
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, Michigan, USA
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15
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Adverse health effects of PCBs on fine motor performance - Analysis of a neurophysiological pathway in the HELPcB surveillance program. Neurotoxicology 2021; 84:146-154. [PMID: 33774065 DOI: 10.1016/j.neuro.2021.03.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 02/21/2021] [Accepted: 03/22/2021] [Indexed: 11/21/2022]
Abstract
Since research literature indicates neurotoxic health effects of polychlorinated biphenyls (PCBs), it is necessary to identify by which mechanism PCBs might affect the human central nervous system and human behavior. In the present study, a neurophysiological pathway is assumed to explain the negative association of PCB exposure and performance in fine motor tasks mediated by the level of the dopamine (DA) metabolite homovanillic acid (HVA). A total of 113 occupationally PCB exposed workers and their relatives from an occupational health monitoring program were examined (89.4 % men). PCBs were analyzed in plasma via human biomonitoring and HVA was assessed in urine. The motor performance series was used to measure two dimensions of fine motor skills with 5 subgroups (accuracy: steadiness, line tracking accuracy; speed: line tracking speed, aiming, tapping). The direct effects of PCBs on fine motor performance and the indirect effects of PCBs on fine motor performance via DA metabolite HVA were tested with multiple regressions. We found significant effects for the accuracy dimension, namely a negative direct effect of PCBs on line tracking accuracy mediated by HVA. Further, an indirect effect could be found for PCBs with steadiness accuracy through HVA. There were no significant effects related to fine motor performances in the speed dimension. These results provide first indications for an underlying neurochemical pathomechanism involving the dopamine system of PCB-related deterioration of fine motor performance regarding accuracy.
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16
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Black CA, Bucher ML, Bradner JM, Jonas L, Igarza K, Miller GW. Assessing Vesicular Monoamine Transport and Toxicity Using Fluorescent False Neurotransmitters. Chem Res Toxicol 2020; 34:1256-1264. [PMID: 33378168 DOI: 10.1021/acs.chemrestox.0c00380] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Impairments in the vesicular packaging of dopamine result in an accumulation of dopamine in the cytosol. Cytosolic dopamine is vulnerable to two metabolic processes-enzymatic catabolism and enzymatic- or auto-oxidation-that form toxic metabolites and generate reactive oxygen species. Alterations in the expression or activity of the vesicular monoamine transporter 2 (VMAT2), which transports monoamines such as dopamine from the cytosol into the synaptic vesicle, result in dysregulated dopamine packaging. Here, we developed a series of assays using the fluorescent false neurotransmitter 206 (FFN206) to visualize VMAT2-mediated vesicular packaging at baseline and following pharmacological and toxicological manipulations. As a proof of principle, we observed a significant reduction in vesicular FFN206 packaging after treatment with the VMAT2 inhibitors reserpine (IC50: 73.1 nM), tetrabenazine (IC50: 30.4 nM), methamphetamine (IC50: 2.4 μM), and methylphenidate (IC50: 94.3 μM). We then applied the assay to investigate the consequences on vesicular packaging by environmental toxicants including the pesticides paraquat, rotenone, and chlorpyrifos, as well as the halogenated compounds unichlor, perfluorooctanesulfonic acid, Paroil, Aroclor 1260, and hexabromocyclododecane. Several of the environmental toxicants showed minor impairment of the vesicular FFN206 loading, suggesting that the toxicants are weak VMAT2 inhibitors at the concentrations tested. The assay presented here can be applied to investigate the effect of additional pharmacological compounds and environmental toxicants on vesicular function, which will provide insight into how exposures to such factors are involved in the pathogenesis of monoaminergic diseases such as Parkinson's disease, and the assay can be used to identify pharmacological agents that influence VMAT2 activity.
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Affiliation(s)
- Carlie A Black
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, Georgia 30322, United States
| | - Meghan L Bucher
- Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, New York 10032, United States
| | - Joshua M Bradner
- Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, New York 10032, United States
| | - Lauren Jonas
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, Georgia 30322, United States
| | - Kenny Igarza
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, Georgia 30322, United States
| | - Gary W Miller
- Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, New York 10032, United States
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Raffetti E, Donato F, De Palma G, Leonardi L, Sileo C, Magoni M. Polychlorinated biphenyls (PCBs) and risk of dementia and Parkinson disease: A population-based cohort study in a North Italian highly polluted area. CHEMOSPHERE 2020; 261:127522. [PMID: 32712378 DOI: 10.1016/j.chemosphere.2020.127522] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Revised: 06/20/2020] [Accepted: 06/23/2020] [Indexed: 06/11/2023]
Abstract
BACKGROUND Serum polychlorinated biphenyls (PCBs) have been associated with some chronic diseases, but little evidence exists on their possible relationship with neurodegenerative diseases. We aimed to assess the relationship between PCB exposure and the occurrence of dementia and Parkinson disease in a prospective cohort study in a highly polluted area (Brescia-Caffaro). METHODS PCB exposure was assessed by measuring serum levels of 24 congeners. Data on the onset of dementia and Parkinson disease were retrieved by the Brescia Health Protection Agency Database. We used Poisson regression models adjusted for possible confounders to calculate rate ratios (RRs). A mediation analysis was performed to evaluate the mediatory role of cardiovascular diseases. RESULTS 699 subjects without neurologic diseases at baseline were enrolled (48.1% males, 63.2 years of mean age) in 2001-2013 and followed up to 2018. During a mean follow-up of 8.8 years, 36 and 20 subjects developed dementia and Parkinson disease. Subjects in the 2nd and 3rd tertiles of the total PCBs distribution, compared with those in the 1st tertile, had a higher risk of dementia (RR = 2.30 and RR = 4.35). The estimates for Parkinson disease included the null value with wide confidence intervals. In the mediation analysis, the association between PCB exposure and dementia was dominated by the direct pathway and not by the hypertension-mediated pathway. CONCLUSIONS We observed a positive association between total PCBs serum levels and the onset of dementia not mediated by hypertension. For Parkinson, the unstable risk estimates did not allow to draw a conclusion on a possible association.
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Affiliation(s)
- Elena Raffetti
- Department of Public Health Sciences, Karolinska Institutet, Italy; ATS Brescia (Brescia Health Protection Agency), Italy; Department of Medical and Surgical Specialties Radiological Sciences and Public Health, Unit of Hygiene, Epidemiology, and Public Health, University of Brescia, Italy.
| | - Francesco Donato
- Department of Medical and Surgical Specialties Radiological Sciences and Public Health, Unit of Hygiene, Epidemiology, and Public Health, University of Brescia, Italy
| | - Giuseppe De Palma
- Department of Medical and Surgical Specialties Radiological Sciences and Public Health, Institute of Occupational Health and Industrial Hygiene, University of Brescia, Italy
| | | | - Claudio Sileo
- ATS Brescia (Brescia Health Protection Agency), Italy
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18
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Sex-specific effects of developmental exposure to polychlorinated biphenyls on neuroimmune and dopaminergic endpoints in adolescent rats. Neurotoxicol Teratol 2020; 79:106880. [PMID: 32259577 DOI: 10.1016/j.ntt.2020.106880] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 03/17/2020] [Accepted: 03/24/2020] [Indexed: 12/22/2022]
Abstract
Exposure to environmental contaminants early in life can have long lasting consequences for physiological function. Polychlorinated biphenyls (PCBs) are a group of ubiquitous contaminants that perturb endocrine signaling and have been associated with altered immune function in children. In this study, we examined the effects of developmental exposure to PCBs on neuroimmune responses to an inflammatory challenge during adolescence. Sprague Dawley rat dams were exposed to a PCB mixture (Aroclor 1242, 1248, 1254, 1:1:1, 20 μg/kg/day) or oil control throughout pregnancy, and adolescent male and female offspring were injected with lipopolysaccharide (LPS, 50 μg/kg, ip) or saline control prior to euthanasia. Gene expression profiling was conducted in the hypothalamus, prefrontal cortex, striatum, and midbrain. In the hypothalamus, PCBs increased expression of genes involved in neuroimmune function, including those within the nuclear factor kappa b (NF-κB) complex, independent of LPS challenge. PCB exposure also increased expression of receptors for dopamine, serotonin, and estrogen in this region. In contrast, in the prefrontal cortex, PCB exposure blunted or induced irregular neuroimmune gene expression responses to LPS challenge. Moreover, neither PCB nor LPS exposure altered expression of neurotransmitter receptors throughout the mesocorticolimbic circuit. Almost all effects were present in males but not females, in agreement with the idea that male neuroimmune cells are more sensitive to perturbation and emphasizing the importance of studying both male and female subjects. Given that altered neuroimmune signaling has been implicated in mental health and substance abuse disorders that often begin during adolescence, these results highlight neuroimmune processes as another mechanism by which early life PCBs can alter brain function later in life.
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19
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Pessah IN, Lein PJ, Seegal RF, Sagiv SK. Neurotoxicity of polychlorinated biphenyls and related organohalogens. Acta Neuropathol 2019; 138:363-387. [PMID: 30976975 PMCID: PMC6708608 DOI: 10.1007/s00401-019-01978-1] [Citation(s) in RCA: 106] [Impact Index Per Article: 21.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Revised: 02/12/2019] [Accepted: 02/19/2019] [Indexed: 01/28/2023]
Abstract
Halogenated organic compounds are pervasive in natural and built environments. Despite restrictions on the production of many of these compounds in most parts of the world through the Stockholm Convention on Persistent Organic Pollutants (POPs), many "legacy" compounds, including polychlorinated biphenyls (PCBs), are routinely detected in human tissues where they continue to pose significant health risks to highly exposed and susceptible populations. A major concern is developmental neurotoxicity, although impacts on neurodegenerative outcomes have also been noted. Here, we review human studies of prenatal and adult exposures to PCBs and describe the state of knowledge regarding outcomes across domains related to cognition (e.g., IQ, language, memory, learning), attention, behavioral regulation and executive function, and social behavior, including traits related to attention-deficit hyperactivity disorder (ADHD) and autism spectrum disorders (ASD). We also review current understanding of molecular mechanisms underpinning these associations, with a focus on dopaminergic neurotransmission, thyroid hormone disruption, calcium dyshomeostasis, and oxidative stress. Finally, we briefly consider contemporary sources of organohalogens that may pose human health risks via mechanisms of neurotoxicity common to those ascribed to PCBs.
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Affiliation(s)
- Isaac N Pessah
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, 1089 VM3B, Davis, CA, 95616, USA.
| | - Pamela J Lein
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, 1089 VM3B, Davis, CA, 95616, USA
| | - Richard F Seegal
- Professor Emeritus, School of Public Health, University at Albany, Rensselaer, NY, USA
| | - Sharon K Sagiv
- Center for Environmental Research and Children's Health (CERCH), School of Public Health, University of California, Berkeley, CA, USA
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20
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Kline EM, Butkovich LM, Bradner JM, Chang J, Gelbard H, Goodfellow V, Caudle WM, Tansey MG. The second generation mixed lineage kinase-3 (MLK3) inhibitor CLFB-1134 protects against neurotoxin-induced nigral dopaminergic neuron loss. Exp Neurol 2019; 318:157-164. [PMID: 31077715 PMCID: PMC6592621 DOI: 10.1016/j.expneurol.2019.05.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Revised: 05/01/2019] [Accepted: 05/07/2019] [Indexed: 11/29/2022]
Abstract
Dopaminergic neurons express mixed lineage kinases which regulate the expression of cell death genes. In Parkinson's disease, cell death via apoptosis is prevalent, and previous work testing mixed lineage kinase inhibitors in animal models suggested the inhibitors had some neuroprotective potential. CLFB-1134 is a new, brain-penetrant inhibitor specific for MLK3, tested here in a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) model of dopaminergic depletion and nigral neuron death in mice. After ensuring that treatment with CLFB-1134 did not alter conversion of MPTP to MPP+, we demonstrated CLFB-1134's inhibition of MLK3 and neuroprotective efficacy. Specifically we evaluated the integrity of the nigrostriatal dopamine system following MPTP by assessing protein expression, high performance liquid chromatography, and immunohistology with stereology. We found that CLFB-1134 achieves protection of striatal dopaminergic terminals and nigral cell bodies when dosed simultaneously or following MPTP treatment. By preventing phosphorylation of JNK and other downstream targets of MLK3, CLFB-1134 protects against the neurotoxin MPTP. Inhibition of MLK3 may be a valid target for future work investigating treatment of Parkinson's disease.
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Affiliation(s)
- Elizabeth M Kline
- Emory University, 615 Michael St, Atlanta, GA 30322, United States of America.
| | - Laura M Butkovich
- Emory University, 615 Michael St, Atlanta, GA 30322, United States of America.
| | - Joshua M Bradner
- Emory University, 1518 Clifton Rd NE, Atlanta, GA 30322, United States of America.
| | - Jianjun Chang
- Emory University, 615 Michael St, Atlanta, GA 30322, United States of America.
| | - Harris Gelbard
- University of Rochester Medical Center, Box 645, 601 Elmwood Avenue, Rochester, NY 14642, United States of America.
| | - Val Goodfellow
- Califia Bio Inc., San Diego, CA, United States of America.
| | - W Michael Caudle
- Emory University, 1518 Clifton Rd NE, Atlanta, GA 30322, United States of America.
| | - Malú G Tansey
- Emory University, 615 Michael St, Atlanta, GA 30322, United States of America.
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21
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Uwimana E, Cagle B, Yeung C, Li X, Patterson EV, Doorn JA, Lehmler HJ. Atropselective Oxidation of 2,2',3,3',4,6'-Hexachlorobiphenyl (PCB 132) to Hydroxylated Metabolites by Human Liver Microsomes and Its Implications for PCB 132 Neurotoxicity. Toxicol Sci 2019; 171:406-420. [PMID: 31268529 PMCID: PMC6760323 DOI: 10.1093/toxsci/kfz150] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Revised: 06/18/2019] [Accepted: 06/18/2019] [Indexed: 02/05/2023] Open
Abstract
Polychlorinated biphenyls (PCBs) have been associated with neurodevelopmental disorders. Several neurotoxic congeners display axial chirality and atropselectively affect cellular targets implicated in PCB neurotoxicity. Only limited information is available regarding the atropselective metabolism of these congeners in humans and their atropselective effects on neurotoxic outcomes. Here we investigate the hypothesis that the oxidation of 2,2',3,3',4,6'-hexachlorobiphenyl (PCB 132) by human liver microsomes (HLMs) and their effects on dopaminergic cells in culture are atropselective. Racemic PCB 132 was incubated with pooled or single donor HLMs, and levels and enantiomeric fractions of PCB 132 and its metabolites were determined gas chromatographically. The major metabolite was either 2,2',3,4,4',6'-hexachlorobiphenyl-3'-ol (3'-140), a 1,2-shift product, or 2,2',3,3',4,6'-hexachlorobiphenyl-5'-ol (5'-132). The PCB 132 metabolite profiles displayed inter-individual differences and depended on the PCB 132 atropisomer. Computational studies suggested that 3'-140 is formed via a 3,4-arene oxide intermediate. The second eluting atropisomer of PCB 132, first eluting atropisomer of 3'-140, and second eluting atropisomer of 5'-132 were enriched in all HLM incubations. Enantiomeric fractions of the PCB 132 metabolites differed only slightly between the single donor HLM preparations investigated. Reactive oxygen species and levels of dopamine and its metabolites were not significantly altered after a 24 h exposure of dopaminergic cells to pure PCB 132 atropisomers. These findings suggest that there are inter-individual differences in the atropselective biotransformation of PCB 132 to its metabolites in humans; however, the resulting atropisomeric enrichment of PCB 132 is unlikely to affect neurotoxic outcomes associated with the endpoints investigated in the study.
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Affiliation(s)
- Eric Uwimana
- Interdisciplinary Graduate Program in Human Toxicology and Department of Occupational and Environmental Health, College of Public Health, University of Iowa, Iowa City, Iowa
| | - Brianna Cagle
- Department of Pharmaceutical Sciences and Experimental Therapeutics, College of Pharmacy, University of Iowa, Iowa City, IA, United States
| | - Coby Yeung
- Department of Chemistry, College of Arts and Sciences, Stony Brook University, Stony Brook, New York
| | - Xueshu Li
- Interdisciplinary Graduate Program in Human Toxicology and Department of Occupational and Environmental Health, College of Public Health, University of Iowa, Iowa City, Iowa
| | - Eric V Patterson
- Department of Chemistry, College of Arts and Sciences, Stony Brook University, Stony Brook, New York
| | - Jonathan A Doorn
- Department of Pharmaceutical Sciences and Experimental Therapeutics, College of Pharmacy, University of Iowa, Iowa City, IA, United States
| | - Hans-Joachim Lehmler
- Interdisciplinary Graduate Program in Human Toxicology and Department of Occupational and Environmental Health, College of Public Health, University of Iowa, Iowa City, Iowa
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22
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Walker DI, Marder ME, Yano Y, Terrell M, Liang Y, Barr DB, Miller GW, Jones DP, Marcus M, Pennell KD. Multigenerational metabolic profiling in the Michigan PBB registry. ENVIRONMENTAL RESEARCH 2019; 172:182-193. [PMID: 30782538 PMCID: PMC6534816 DOI: 10.1016/j.envres.2019.02.018] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Revised: 01/12/2019] [Accepted: 02/12/2019] [Indexed: 05/17/2023]
Abstract
Although polychlorinated biphenyls and polybrominated biphenyls are no longer manufactured the United States, biomonitoring in human populations show that exposure to these pollutants persist in human tissues. The objective of this study was to identify metabolic variations associated with exposure to 2,2'4,4',5,5'-hexabromobiphenyl (PBB-153) and 2,2'4,4',5,5'-hexachlorobiphenyl (PCB-153) in two generations of participants enrolled in the Michigan PBB Registry (http://pbbregistry.emory.edu/). Untargeted, high-resolution metabolomic profiling of plasma collected from 156 individuals was completed using liquid chromatography with high-resolution mass spectrometry. PBB-153 and PCB-153 levels were measured in the same individuals using targeted gas chromatography-tandem mass spectrometry and tested for dose-dependent correlation with the metabolome. Biological response to these exposures were evaluated using identified endogenous metabolites and pathway enrichment. When compared to lipid-adjusted concentrations for adults in the National Health and Nutrition Examination Survey (NHANES) for years 2003-2004, PCB-153 levels were consistent with similarly aged individuals, whereas PBB-153 concentrations were elevated (p<0.0001) in participants enrolled in the Michigan PBB Registry. Metabolic alterations were correlated with PBB-153 and PCB-153 in both generations of participants, and included changes in pathways related to catecholamine metabolism, cellular respiration, essential fatty acids, lipids and polyamine metabolism. These pathways were consistent with pathophysiological changes observed in neurodegenerative disease and included previously identified metabolomic markers of Parkinson's disease. To determine if the metabolic alterations detected in this study are replicated other cohorts, we evaluated correlation of PBB-153 and PCB-153 with plasma fatty acids measured in NHANES. Both pollutants showed similar associations with fatty acids previously linked to PCB exposure. Thus, the results from this study show metabolic alterations correlated with PBB-153 and PCB-153 exposure can be detected in human populations and are consistent with health outcomes previously reported in epidemiological and mechanistic studies.
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Affiliation(s)
- Douglas I Walker
- Department of Civil and Environmental Engineering, Tufts University, 200 College Ave, Medford MA 02155, United States; Clinical Biomarkers Laboratory, Division of Pulmonary, Allergy, and Critical Care Medicine, Emory University School of Medicine, 615 Michael St, Atlanta GA 30322, United States.
| | - M Elizabeth Marder
- Department of Environmental Health, Rollins School of Public Health, Emory University, 1518 Clifton Rd, Atlanta GA 30322, United States.
| | - Yukiko Yano
- Division of Environmental Health Sciences, School of Public Health, University of California, Berkeley, 50 University Ave Hall #7360, Berkeley CA 94720, United States.
| | - Metrecia Terrell
- Department of Epidemiology, Rollins School of Public Health, Emory University, 1518 Clifton Rd, Atlanta GA 30322, United States.
| | - Yongliang Liang
- Clinical Biomarkers Laboratory, Division of Pulmonary, Allergy, and Critical Care Medicine, Emory University School of Medicine, 615 Michael St, Atlanta GA 30322, United States.
| | - Dana Boyd Barr
- Department of Environmental Health, Rollins School of Public Health, Emory University, 1518 Clifton Rd, Atlanta GA 30322, United States.
| | - Gary W Miller
- Department of Environmental Health, Rollins School of Public Health, Emory University, 1518 Clifton Rd, Atlanta GA 30322, United States.
| | - Dean P Jones
- Clinical Biomarkers Laboratory, Division of Pulmonary, Allergy, and Critical Care Medicine, Emory University School of Medicine, 615 Michael St, Atlanta GA 30322, United States.
| | - Michele Marcus
- Department of Epidemiology, Rollins School of Public Health, Emory University, 1518 Clifton Rd, Atlanta GA 30322, United States.
| | - Kurt D Pennell
- Department of Civil and Environmental Engineering, Tufts University, 200 College Ave, Medford MA 02155, United States.
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Colter BT, Garber HF, Fleming SM, Fowler JP, Harding GD, Hooven MK, Howes AA, Infante SK, Lang AL, MacDougall MC, Stegman M, Taylor KR, Curran CP. Ahr and Cyp1a2 genotypes both affect susceptibility to motor deficits following gestational and lactational exposure to polychlorinated biphenyls. Neurotoxicology 2019; 65:125-134. [PMID: 29409959 DOI: 10.1016/j.neuro.2018.01.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Revised: 01/16/2018] [Accepted: 01/21/2018] [Indexed: 02/04/2023]
Abstract
Polychlorinated biphenyls (PCBs) are persistent organic pollutants known to cause adverse health effects and linked to neurological deficits in both human and animal studies. Children born to exposed mothers are at highest risk of learning and memory and motor deficits. We developed a mouse model that mimics human variation in the aryl hydrocarbon receptor and cytochrome P450 1A2 (CYP1A2) to determine if genetic variation increases susceptibility to developmental PCB exposure. In our previous studies, we found that high-affinity AhrbCyp1a2(-/-) and poor-affinity AhrdCyp1a2(-/-) knockout mice were most susceptible to learning and memory deficits following developmental PCB exposure compared with AhrbCyp1a2(+/+) wild type mice (C57BL/6J strain). Our follow-up studies focused on motor deficits, because human studies have identified PCBs as a potential risk factor for Parkinson's disease. Dams were treated with an environmentally relevant PCB mixture at gestational day 10 and postnatal day 5. We used a motor battery that included tests of nigrostriatal function as well as cerebellar function, because PCBs deplete thyroid hormone, which is essential to normal cerebellar development. There was a significant effect of PCB treatment in the rotarod test with impaired performance in all three genotypes, but decreased motor learning as well in the two Cyp1a2(-/-) knockout lines. Interestingly, we found a main effect of genotype with corn oil-treated control Cyp1a2(-/-) mice performing significantly worse than Cyp1a2(+/+) wild type mice. In contrast, we found that PCB-treated high-affinity Ahrb mice were most susceptible to disruption of nigrostriatal function with the greatest deficits in AhrbCyp1a2(-/-) mice. We conclude that differences in AHR affinity combined with the absence of CYP1A2 protein affect susceptibility to motor deficits following developmental PCB exposure.
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Affiliation(s)
- Breann T Colter
- Department of Biological Sciences, Northern Kentucky University, Highland Heights, KY, 41076, USA
| | - Helen Frances Garber
- Department of Biological Sciences, Northern Kentucky University, Highland Heights, KY, 41076, USA
| | - Sheila M Fleming
- Department of Psychology and Neurology, University of Cincinnati, Cincinnati, OH, 45267, USA
| | - Jocelyn Phillips Fowler
- Department of Biological Sciences, Northern Kentucky University, Highland Heights, KY, 41076, USA
| | - Gregory D Harding
- Department of Biological Sciences, Northern Kentucky University, Highland Heights, KY, 41076, USA
| | - Molly Kromme Hooven
- Department of Biological Sciences, Northern Kentucky University, Highland Heights, KY, 41076, USA
| | - Amy Ashworth Howes
- Department of Biological Sciences, Northern Kentucky University, Highland Heights, KY, 41076, USA
| | - Smitha Krishnan Infante
- Department of Biological Sciences, Northern Kentucky University, Highland Heights, KY, 41076, USA
| | - Anna L Lang
- Department of Biological Sciences, Northern Kentucky University, Highland Heights, KY, 41076, USA
| | | | - Melinda Stegman
- Department of Biological Sciences, Northern Kentucky University, Highland Heights, KY, 41076, USA
| | - Kelsey Rae Taylor
- Department of Biological Sciences, Northern Kentucky University, Highland Heights, KY, 41076, USA
| | - Christine Perdan Curran
- Department of Biological Sciences, Northern Kentucky University, Highland Heights, KY, 41076, USA.
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Enayah SH, Vanle BC, Fuortes LJ, Doorn JA, Ludewig G. PCB95 and PCB153 change dopamine levels and turn-over in PC12 cells. Toxicology 2017; 394:93-101. [PMID: 29233657 DOI: 10.1016/j.tox.2017.12.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Revised: 11/10/2017] [Accepted: 12/06/2017] [Indexed: 10/18/2022]
Abstract
Polychlorinated biphenyls (PCB) exposure at low chronic levels is a significant public health concern. Animal and epidemiological studies indicate that low PCB body burden may cause neurotoxicity and be a risk factor for neurodegenerative diseases. In the current study, we measured the ability of two non-dioxin like PCBs, 2,2',4,4',5,5'-hexachlorobiphenyl (PCB153) and 2,2'3,5',6-pentachlorobiphenyl (PCB95), to alter dopamine (DA) levels and metabolism using the dopaminergic PC12 cell line. Our hypothesis is that treatment of PC12 cells with non-toxic concentrations of PCB153 or PCB95 for 12 and 24 h will have different effects due to different congener structures. Levels of DA and of 3,4-dihydroxyphenylacetaldehyde (DOPAL), 3, 4-dihyroxylphenylethanol (DOPET), and 3,4-dihyroxylphenylacetic acid (DOPAC) metabolite, gene expression of the dopamine synthesis enzyme tyrosine hydroxylase (TH) and the vesicular monoamine transporter (VMAT2), and gene expression of the anti-oxidant enzymes Cu/Zn and Mn superoxide oxidase (Cu/ZnSOD, MnSOD), glutathione peroxidase (GPx) and catalase were determined. PCB153 decreased intracellular and extracellular levels of DA after 12 h exposure and this was consistent with an increase in DA metabolites. After 24 h, the level of DA in medium increased compared to the control. In contrast, PCB95 exposure increased the intracellular DA level and decreased DA in medium consistent with a down-regulation of VMAT2 expression at 12 h. After 24 h exposure, PCB95 increased DA levels in media. Expression of TH mRNA increased slightly following 12 h but not at 24 h exposure. MnSOD mRNA increased up to 6-7 fold and Cu/ZnSOD increased less than two-fold after treatment with both congeners. Catalase expression was up-regulated following 24 h exposure to PCB153 and PCB95, but GPx expression was down-regulated after 12 h exposure to PCB95 only. These results suggest that PCB153 and PCB95 are neurotoxic and affect DA turnover with structure-dependent differences between these two congeners.
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Affiliation(s)
- Sabah H Enayah
- Interdisciplinary Graduate Program in Human Toxicology, University of Iowa, United States
| | - Brigitte C Vanle
- Department of Pharmaceutical Sciences & Experimental Therapeutics, University of Iowa, United States
| | - Laurence J Fuortes
- Interdisciplinary Graduate Program in Human Toxicology, University of Iowa, United States; Department of Occupational & Environmental Health, University of Iowa, United States
| | - Jonathan A Doorn
- Interdisciplinary Graduate Program in Human Toxicology, University of Iowa, United States; Department of Pharmaceutical Sciences & Experimental Therapeutics, University of Iowa, United States
| | - Gabriele Ludewig
- Interdisciplinary Graduate Program in Human Toxicology, University of Iowa, United States; Department of Occupational & Environmental Health, University of Iowa, United States.
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25
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Klinefelter K, Hooven MK, Bates C, Colter BT, Dailey A, Infante SK, Kania-Korwel I, Lehmler HJ, López-Juárez A, Ludwig CP, Curran CP. Genetic differences in the aryl hydrocarbon receptor and CYP1A2 affect sensitivity to developmental polychlorinated biphenyl exposure in mice: relevance to studies of human neurological disorders. Mamm Genome 2017; 29:112-127. [PMID: 29197979 DOI: 10.1007/s00335-017-9728-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Accepted: 11/28/2017] [Indexed: 01/28/2023]
Abstract
Polychlorinated biphenyls (PCBs) are persistent organic pollutants that remain a human health concern with newly discovered sources of contamination and ongoing bioaccumulation and biomagnification. Children exposed during early brain development are at highest risk of neurological deficits, but highly exposed adults reportedly have an increased risk of Parkinson's disease. Our previous studies found allelic differences in the aryl hydrocarbon receptor and cytochrome P450 1A2 (CYP1A2) affect sensitivity to developmental PCB exposure, resulting in cognitive deficits and motor dysfunction. High-affinity Ahr b Cyp1a2(-/-) mice were most sensitive compared with poor-affinity Ahr d Cyp1a2(-/-) and wild-type Ahr b Cyp1a2(+/+) mice. Our follow-up studies assessed biochemical, histological, and gene expression changes to identify the brain regions and pathways affected. We also measured PCB and metabolite levels in tissues to determine if genotype altered toxicokinetics. We found evidence of AHR-mediated toxicity with reduced thymus and spleen weights and significantly reduced thyroxine at P14 in PCB-exposed pups. In the brain, the greatest changes were seen in the cerebellum where a foliation defect was over-represented in Cyp1a2(-/-) mice. In contrast, we found no difference in tyrosine hydroxylase immunostaining in the striatum. Gene expression patterns varied across the three genotypes, but there was clear evidence of AHR activation. Distribution of parent PCB congeners also varied by genotype with strikingly high levels of PCB 77 in poor-affinity Ahr d Cyp1a2(-/-) while Ahr b Cyp1a2(+/+) mice effectively sequestered coplanar PCBs in the liver. Together, our data suggest that the AHR pathway plays a role in developmental PCB neurotoxicity, but we found little evidence that developmental exposure is a risk factor for Parkinson's disease.
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Affiliation(s)
- Kelsey Klinefelter
- Department of Biological Sciences, Northern Kentucky University, SC344 Nunn Drive, Highland Heights, KY, 41076, USA.,Division of Developmental Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, USA
| | - Molly Kromme Hooven
- Department of Biological Sciences, Northern Kentucky University, SC344 Nunn Drive, Highland Heights, KY, 41076, USA.,Division of Developmental Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, USA
| | - Chloe Bates
- Department of Biological Sciences, Northern Kentucky University, SC344 Nunn Drive, Highland Heights, KY, 41076, USA
| | - Breann T Colter
- Department of Biological Sciences, Northern Kentucky University, SC344 Nunn Drive, Highland Heights, KY, 41076, USA
| | - Alexandra Dailey
- Department of Biological Sciences, Northern Kentucky University, SC344 Nunn Drive, Highland Heights, KY, 41076, USA
| | - Smitha Krishnan Infante
- Department of Biological Sciences, Northern Kentucky University, SC344 Nunn Drive, Highland Heights, KY, 41076, USA
| | - Izabela Kania-Korwel
- Department of Occupational and Environmental Health, College of Public Health, University of Iowa, Iowa City, IA, 52242, USA
| | - Hans-Joachim Lehmler
- Department of Occupational and Environmental Health, College of Public Health, University of Iowa, Iowa City, IA, 52242, USA
| | - Alejandro López-Juárez
- Division of Experimental Hematology and Cancer Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, USA
| | - Clare Pickering Ludwig
- Department of Biological Sciences, Northern Kentucky University, SC344 Nunn Drive, Highland Heights, KY, 41076, USA
| | - Christine Perdan Curran
- Department of Biological Sciences, Northern Kentucky University, SC344 Nunn Drive, Highland Heights, KY, 41076, USA.
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Haijima A, Lesmana R, Shimokawa N, Amano I, Takatsuru Y, Koibuchi N. Differential neurotoxic effects of in utero and lactational exposure to hydroxylated polychlorinated biphenyl (OH-PCB 106) on spontaneous locomotor activity and motor coordination in young adult male mice. J Toxicol Sci 2017; 42:407-416. [PMID: 28717099 DOI: 10.2131/jts.42.407] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
We investigated whether in utero or lactational exposure to 4-hydroxy-2',3,3',4',5'-pentachlorobiphenyl (OH-PCB 106) affects spontaneous locomotor activity and motor coordination in young adult male mice. For in utero exposure, pregnant C57BL/6J mice received 0.05 or 0.5 mg/kg body weight of OH-PCB 106 or corn oil vehicle via gavage every second day from gestational day 10 to 18. For lactational exposure, the different groups of dams received 0.05 or 0.5 mg/kg body weight of OH-PCB 106 or corn oil vehicle via gavage every second day from postpartum day 3 to 13. At 6-7 weeks of age, the spontaneous locomotor activities of male offspring were evaluated for a 24-hr continuous session in a home cage and in an open field for 30-min. Motor coordination function on an accelerating rotarod was also measured. Mice exposed prenatally to OH-PCB 106 showed increased spontaneous locomotor activities during the dark phase in the home cage and during the first 10-min in the open field compared with control mice. Mice exposed lactationally to OH-PCB 106, however, did not show a time-dependent decrease in locomotor activity in the open field. Instead, their locomotor activity increased significantly during the second 10-min block. In addition, mice exposed lactationally to OH-PCB 106 displayed impairments in motor coordination in the rotarod test. These results suggest that perinatal exposure to OH-PCB 106 affects motor behaviors in young adult male mice. Depending on the period of exposure, OH-PCB 106 may have different effects on neurobehavioral development.
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Affiliation(s)
- Asahi Haijima
- Center for Medical Education, Gunma University Graduate School of Medicine.,Department of Integrative Physiology, Gunma University Graduate School of Medicine
| | - Ronny Lesmana
- Department of Integrative Physiology, Gunma University Graduate School of Medicine.,Department of Physiology, Universitas Padjadjaran, Indonesia
| | - Noriaki Shimokawa
- Department of Integrative Physiology, Gunma University Graduate School of Medicine.,Department of Nutrition, Takasaki University of Health and Welfare
| | - Izuki Amano
- Department of Integrative Physiology, Gunma University Graduate School of Medicine
| | - Yusuke Takatsuru
- Department of Integrative Physiology, Gunma University Graduate School of Medicine
| | - Noriyuki Koibuchi
- Department of Integrative Physiology, Gunma University Graduate School of Medicine
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Rosenquist AH, Høyer BB, Julvez J, Sunyer J, Pedersen HS, Lenters V, Jönsson BAG, Bonde JP, Toft G. Prenatal and Postnatal PCB-153 and p, p'-DDE Exposures and Behavior Scores at 5–9 Years of Age among Children in Greenland and Ukraine. ENVIRONMENTAL HEALTH PERSPECTIVES 2017; 125:107002. [PMID: 28974479 PMCID: PMC5933308 DOI: 10.1289/ehp553] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Revised: 08/29/2017] [Accepted: 08/29/2017] [Indexed: 05/06/2023]
Abstract
BACKGROUND Studies have reported some evidence of adverse effects of organochlorine exposures on child development, but the results have been inconsistent, and few studies have evaluated associations with child behavior. OBJECTIVE We investigated the association between prenatal and early-life exposures to 2,2',4,4',5,5'-hexachlorobiphenyl (PCB-153) and 1,1-dichloro-2,2-bis(p-chlorophenyl)-ethylene (p,p'-DDE) and behaviors in children between 5 and 9 y of age. METHODS In the Biopersistent organochlorines in diet and human fertility: Epidemiologic studies of time to pregnancy and semen quality in Inuit and European populations (INUENDO) cohort, consisting of mother-child pairs from Greenland and Ukraine (n=1,018), maternal serum PCB-153 and p,p'-DDE concentrations were measured during pregnancy, and cumulative postnatal exposures during the first 12 months after delivery were estimated using a pharmacokinetic model. Parents completed the Strengths and Difficulties Questionnaire (SDQ), and children's behaviors were dichotomized as abnormal (high) versus normal/borderline for five SDQ subscales and the total difficulties score. RESULTS The total difficulties score, an overall measure of abnormal behavior, was not clearly associated with pre- or postnatal exposures to PCB-153 or to p,p'-DDE. However, pooled adjusted odds ratios (ORs) for high conduct problem scores with a doubling of exposure were 1.19 (95% CI: 0.99, 1.42) and 1.16 (95% CI: 0.96, 1.41) for pre- and postnatal PCB-153, respectively, and 1.25 (95% CI: 1.04, 1.51) and 1.24 (95% CI: 1.01, 1.51) for pre- and postnatal p,p'-DDE, respectively. Corresponding ORs for high hyperactivity scores were 1.24 (95% CI: 0.94, 1.62) and 1.08 (95% CI: 0.81, 1.45) for pre- and postnatal PCB-153, respectively, and 1.43 (95% CI: 1.06, 1.92) and 1.27 (95% CI: 0.93, 1.73) for pre- and postnatal p,p'-DDE, respectively. CONCLUSION Prenatal and early postnatal exposures to p,p'-DDE and PCB-153 were associated with a higher prevalence of abnormal scores for conduct and hyperactivity at 5–9 y of age in our study population. These findings provide further support for the importance of minimizing organochlorine exposures to young children and to women of childbearing age. https://doi.org/10.1289/EHP553.
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Affiliation(s)
- Aske Hess Rosenquist
- Department of Clinical Epidemiology, Aarhus University Hospital , Aarhus, Denmark
| | - Birgit Bjerre Høyer
- Department of Occupational and Environmental Medicine, Copenhagen University Hospital , Copenhagen, Denmark
- Department of Clinical Epidemiology, Aarhus University Hospital , Aarhus, Denmark
| | - Jordi Julvez
- ISGlobal, Centre for Research in Environmental Epidemiology (CREAL) , Barcelona, Catalonia, Spain
| | - Jordi Sunyer
- ISGlobal, Centre for Research in Environmental Epidemiology (CREAL) , Barcelona, Catalonia, Spain
| | | | - Virissa Lenters
- Division of Environmental Epidemiology, Institute for Risk Assessment Sciences, Utrecht University , Utrecht, Netherlands
| | - Bo A G Jönsson
- Division of Occupational and Environmental Medicine, Lund University , Lund, Sweden
| | - Jens Peter Bonde
- Department of Occupational and Environmental Medicine, Copenhagen University Hospital , Copenhagen, Denmark
| | - Gunnar Toft
- Department of Clinical Epidemiology, Aarhus University Hospital , Aarhus, Denmark
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28
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Pham-Lake C, Aronoff EB, Camp CR, Vester A, Peters SJ, Caudle WM. Impairment in the mesohippocampal dopamine circuit following exposure to the brominated flame retardant, HBCDD. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2017; 50:167-174. [PMID: 28214749 PMCID: PMC5382642 DOI: 10.1016/j.etap.2017.02.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Accepted: 02/03/2017] [Indexed: 06/06/2023]
Abstract
Many chemicals have been used to increase the safety of consumer products by reducing their flammability and risk for ignition. Recent focus on brominated flame retardants, such as polybrominated diphenyl ethers (PBDEs) has shown them to contribute to neurobehavioral deficits in children, including learning and memory. As the manufacture and use of PBDEs have been reduced, replacement chemicals, such as hexabromocyclododecane (HBCDD) have been substituted. Our current study evaluated the neurotoxicity of HBCDD, concentrating on dopaminergic innervation to the hippocampus. Using an in vivo model, we exposed male mice to HBCDD and then assessed alterations to the dopamine synapse 6 weeks later. These exposures elicited significant reductions in presynaptic dopaminergic proteins, including TH, COMT, MAO-B, DAT, VMAT2, and alpha-synuclein. In contrast, postsynaptic dopamine receptors were not impaired. These findings suggest that the mesohippocampal dopamine circuit is vulnerable to HBCDD and the dopamine terminal may be a selective target for alteration.
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Affiliation(s)
- Camille Pham-Lake
- Department of Environmental Health, Rollins School of Public Health Emory University, Atlanta, GA 30322-3090, USA
| | - Elizabeth B Aronoff
- Department of Environmental Health, Rollins School of Public Health Emory University, Atlanta, GA 30322-3090, USA
| | - Chad R Camp
- Department of Environmental Health, Rollins School of Public Health Emory University, Atlanta, GA 30322-3090, USA
| | - Aimee Vester
- Department of Environmental Health, Rollins School of Public Health Emory University, Atlanta, GA 30322-3090, USA
| | - Sam J Peters
- Department of Environmental Health, Rollins School of Public Health Emory University, Atlanta, GA 30322-3090, USA
| | - W Michael Caudle
- Department of Environmental Health, Rollins School of Public Health Emory University, Atlanta, GA 30322-3090, USA; Center for Neurodegenerative Disease, School of Medicine, Emory University Atlanta, GA 30322-3090, USA.
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29
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Nandipati S, Litvan I. Environmental Exposures and Parkinson's Disease. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2016; 13:ijerph13090881. [PMID: 27598189 PMCID: PMC5036714 DOI: 10.3390/ijerph13090881] [Citation(s) in RCA: 122] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Revised: 08/29/2016] [Accepted: 08/30/2016] [Indexed: 12/21/2022]
Abstract
Parkinson’s disease (PD) affects millions around the world. The Braak hypothesis proposes that in PD a pathologic agent may penetrate the nervous system via the olfactory bulb, gut, or both and spreads throughout the nervous system. The agent is unknown, but several environmental exposures have been associated with PD. Here, we summarize and examine the evidence for such environmental exposures. We completed a comprehensive review of human epidemiologic studies of pesticides, selected industrial compounds, and metals and their association with PD in PubMed and Google Scholar until April 2016. Most studies show that rotenone and paraquat are linked to increased PD risk and PD-like neuropathology. Organochlorines have also been linked to PD in human and laboratory studies. Organophosphates and pyrethroids have limited but suggestive human and animal data linked to PD. Iron has been found to be elevated in PD brain tissue but the pathophysiological link is unclear. PD due to manganese has not been demonstrated, though a parkinsonian syndrome associated with manganese is well-documented. Overall, the evidence linking paraquat, rotenone, and organochlorines with PD appears strong; however, organophosphates, pyrethroids, and polychlorinated biphenyls require further study. The studies related to metals do not support an association with PD.
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Affiliation(s)
- Sirisha Nandipati
- Department of Neurosciences Movement Disorders Center, University of California, San Diego, CA 92093, USA.
| | - Irene Litvan
- Department of Neurosciences Movement Disorders Center, University of California, San Diego, CA 92093, USA.
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30
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Patel R, Bradner JM, Stout KA, Caudle WM. Alteration to Dopaminergic Synapses Following Exposure to Perfluorooctane Sulfonate (PFOS), in Vitro and in Vivo. Med Sci (Basel) 2016; 4:medsci4030013. [PMID: 29083377 PMCID: PMC5635798 DOI: 10.3390/medsci4030013] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Revised: 08/04/2016] [Accepted: 08/09/2016] [Indexed: 12/30/2022] Open
Abstract
Our understanding of the contribution exposure to environmental toxicants has on neurological disease continues to evolve. Of these, Parkinson’s disease (PD) has been shown to have a strong environmental component to its etiopathogenesis. However, work is still needed to identify and characterize environmental chemicals that could alter the expression and function of the nigrostriatal dopamine system. Of particular interest is the neurotoxicological effect of perfluorinated compounds, such as perfluorooctane sulfonate (PFOS), which has been demonstrated to alter aspects of dopamine signaling. Using in vitro approaches, we have elaborated these initial findings to demonstrate the neurotoxicity of PFOS to the SH-SY5Y neuroblastoma cell line and dopaminergic primary cultured neurons. Using an in vivo model, we did not observe a deficit to dopaminergic terminals in the striatum of mice exposed to 10 mg/kg PFOS for 14 days. However, subsequent exposure to the selective dopaminergic neurotoxin, 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) significantly reduced the expression of dopamine transporter (DAT) and tyrosine hydroxylase (TH), and resulted in an even greater reduction in DAT expression in animals previously exposed to PFOS. These findings suggest that PFOS is neurotoxic to the nigrostriatal dopamine circuit and this neurotoxicity could prime the dopamine terminal to more extensive damage following additional toxicological insults.
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Affiliation(s)
- Rahul Patel
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA 30322, USA.
| | - Joshua M Bradner
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA 30322, USA.
- Center for Neurodegenerative Disease, School of Medicine, Emory University, Atlanta, GA 30322, USA.
| | - Kristen A Stout
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA 30322, USA.
- Center for Neurodegenerative Disease, School of Medicine, Emory University, Atlanta, GA 30322, USA.
| | - William Michael Caudle
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA 30322, USA.
- Center for Neurodegenerative Disease, School of Medicine, Emory University, Atlanta, GA 30322, USA.
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31
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Pinson A, Bourguignon JP, Parent AS. Exposure to endocrine disrupting chemicals and neurodevelopmental alterations. Andrology 2016; 4:706-22. [PMID: 27285165 DOI: 10.1111/andr.12211] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Revised: 03/25/2016] [Accepted: 04/05/2016] [Indexed: 01/24/2023]
Abstract
The developing brain is remarkably malleable as neural circuits are formed and these circuits are strongly dependent on hormones for their development. For those reasons, the brain is very vulnerable to the effects of endocrine-disrupting chemicals (EDCs) during critical periods of development. This review focuses on three ubiquitous endocrine disruptors that are known to disrupt the thyroid function and are associated with neurobehavioral deficits: polychlorinated biphenyls, polybrominated diphenyl ethers, and bisphenol A. The human and rodent data suggesting effects of those EDCs on memory, cognition, and social behavior are discussed. Their mechanisms of action go beyond relative hypothyroidism with effects on neurotransmitter release and calcium signaling.
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Affiliation(s)
- A Pinson
- Neuroendocrinology Unit, GIGA Neurosciences, University of Liege, Liège, Belgium
| | - J P Bourguignon
- Neuroendocrinology Unit, GIGA Neurosciences, University of Liege, Liège, Belgium
| | - A S Parent
- Neuroendocrinology Unit, GIGA Neurosciences, University of Liege, Liège, Belgium
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32
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Bentum JK, Dodoo DK, Kwakye PK, Essumang DK, Adjei GA. Spatial and Temporal Distribution of Polychlorinated Biphenyl Residues in Tropical Soils. ACTA ACUST UNITED AC 2016. [DOI: 10.4236/ojapps.2016.64024] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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33
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Choi J, Polcher A, Joas A. Systematic literature review on Parkinson's disease and Childhood Leukaemia and mode of actions for pesticides. ACTA ACUST UNITED AC 2016. [DOI: 10.2903/sp.efsa.2016.en-955] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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34
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Elnar AA, Allouche A, Desor F, Yen FT, Soulimani R, Oster T. Lactational exposure of mice to low levels of non-dioxin-like polychlorinated biphenyls increases susceptibility to neuronal stress at a mature age. Neurotoxicology 2015; 53:314-320. [PMID: 26480858 DOI: 10.1016/j.neuro.2015.10.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2015] [Accepted: 10/05/2015] [Indexed: 11/27/2022]
Abstract
Lactational exposure to low levels of the sum of the six indicator polychlorinated biphenyls (Σ6 NDL-PCBs, 10ng/kg/day) is known to lead to persistent anxious behavior in young and adult offspring mice at postnatal days 40 and 160, respectively. At more advanced life stages, we evaluated the effects on the mouse brain of neuronal stress induced by the synaptotoxic amyloid-beta (Aβ) peptide. Perinatal exposure of lactating mice to Σ6 NDL-PCBs did not affect short-term memory performances of their offspring male mice aged 14 months as compared to control PCB-naive mice. However, following intracerebroventricular injection of soluble Aβ oligomers, significant impairments in long-term memory were detected in the mice that had been lactationally treated with Σ6 NDL-PCBs. In addition, immunoblot analyses of the synaptosomal fraction of hippocampal tissues from treated mice revealed a lower expression of the synaptic proteins synaptophysin and PSD-95. Though preliminary, our findings suggest for the first time that early exposure to low levels of NDL-PCBs induce late neuronal vulnerability to amyloid stress. Additional experiments are needed to confirm whether early environmental influences are involved in the etiology of brain aging and cognitive decline.
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Affiliation(s)
- Arpiné Ardzivian Elnar
- Neurotoxicologie Alimentaire et Bioactivité, MRCA, BP 4102, 57040 Metz, France; Université de Lorraine, Unité de Recherche Animal et Fonctionnalités des Produits Animaux (UR AFPA), EA3998, INRA USC 0340, France.
| | - Ahmad Allouche
- Biodisponibilité et Fonctionnalités des Lipides Alimentaires, BFLA, ENSAIA, Avenue de la forêt de Haye, 54500 Vandœuvre-lès-Nancy, France; Université de Lorraine, Unité de Recherche Animal et Fonctionnalités des Produits Animaux (UR AFPA), EA3998, INRA USC 0340, France
| | - Frédéric Desor
- Neurotoxicologie Alimentaire et Bioactivité, MRCA, BP 4102, 57040 Metz, France; Université de Lorraine, Unité de Recherche Animal et Fonctionnalités des Produits Animaux (UR AFPA), EA3998, INRA USC 0340, France
| | - Frances T Yen
- Biodisponibilité et Fonctionnalités des Lipides Alimentaires, BFLA, ENSAIA, Avenue de la forêt de Haye, 54500 Vandœuvre-lès-Nancy, France; Université de Lorraine, Unité de Recherche Animal et Fonctionnalités des Produits Animaux (UR AFPA), EA3998, INRA USC 0340, France
| | - Rachid Soulimani
- Neurotoxicologie Alimentaire et Bioactivité, MRCA, BP 4102, 57040 Metz, France; Université de Lorraine, Unité de Recherche Animal et Fonctionnalités des Produits Animaux (UR AFPA), EA3998, INRA USC 0340, France
| | - Thierry Oster
- Biodisponibilité et Fonctionnalités des Lipides Alimentaires, BFLA, ENSAIA, Avenue de la forêt de Haye, 54500 Vandœuvre-lès-Nancy, France; Université de Lorraine, Unité de Recherche Animal et Fonctionnalités des Produits Animaux (UR AFPA), EA3998, INRA USC 0340, France
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Alter SP, Stout KA, Lohr KM, Taylor TN, Shepherd KR, Wang M, Guillot TS, Miller GW. Reduced vesicular monoamine transport disrupts serotonin signaling but does not cause serotonergic degeneration. Exp Neurol 2015; 275 Pt 1:17-24. [PMID: 26428905 DOI: 10.1016/j.expneurol.2015.09.016] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2015] [Revised: 09/11/2015] [Accepted: 09/26/2015] [Indexed: 10/23/2022]
Abstract
We previously demonstrated that mice with reduced expression of the vesicular monoamine transporter 2 (VMAT2 LO) undergo age-related degeneration of the catecholamine-producing neurons of the substantia nigra pars compacta and locus ceruleus and exhibit motor disturbances and depressive-like behavior. In this work, we investigated the effects of reduced vesicular transport on the function and viability of serotonin neurons in these mice. Adult (4-6 months of age), VMAT2 LO mice exhibit dramatically reduced (90%) serotonin release capacity, as measured by fast scan cyclic voltammetry. We observed changes in serotonin receptor responsivity in in vivo pharmacological assays. Aged (months) VMAT2 LO mice exhibited abolished 5-HT1A autoreceptor sensitivity, as determined by 8-OH-DPAT (0.1 mg/kg) induction of hypothermia. When challenged with the 5HT2 agonist, 2,5-dimethoxy-4-iodoamphetamine (1 mg/kg), VMAT2 LO mice exhibited a marked increase (50%) in head twitch responses. We observed sparing of serotonergic terminals in aged mice (18-24 months) throughout the forebrain by SERT immunohistochemistry and [(3)H]-paroxetine binding in striatal homogenates of aged VMAT2 LO mice. In contrast to their loss of catecholamine neurons of the substantia nigra and locus ceruleus, aged VMAT2 LO mice do not exhibit a change in the number of serotonergic (TPH2+) neurons within the dorsal raphe, as measured by unbiased stereology at 26-30 months. Collectively, these data indicate that reduced vesicular monoamine transport significantly disrupts serotonergic signaling, but does not drive degeneration of serotonin neurons.
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Affiliation(s)
- Shawn P Alter
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA, United States
| | - Kristen A Stout
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA, United States
| | - Kelly M Lohr
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA, United States
| | - Tonya N Taylor
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA, United States
| | - Kennie R Shepherd
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA, United States
| | - Minzheng Wang
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA, United States
| | - Thomas S Guillot
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA, United States
| | - Gary W Miller
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA, United States; Center for Neurodegenerative Disease, School of Medicine, Emory University, Atlanta, GA, United States.
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Genskow KR, Bradner JM, Hossain MM, Richardson JR, Caudle WM. Selective damage to dopaminergic transporters following exposure to the brominated flame retardant, HBCDD. Neurotoxicol Teratol 2015; 52:162-9. [PMID: 26073293 DOI: 10.1016/j.ntt.2015.06.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2015] [Revised: 06/05/2015] [Accepted: 06/09/2015] [Indexed: 12/01/2022]
Abstract
Over the last several decades, the use of halogenated organic compounds has become the cause of environmental and human health concerns. Of particular notoriety has been the establishment of the neurotoxicity of polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs). The subsequent banning of PBDEs has led to greatly increased use of 1,2,5,6,9,10-hexabromocyclododecane (HBCDD, also known as HBCD) as a flame retardant in consumer products. The physiochemical similarities between HBCDD and PBDEs suggest that HBCDD may also be neurotoxic to the dopamine system, which is specifically damaged in Parkinson disease (PD). The purpose of this study was to assess the neurotoxicity of HBCDD on the nigrostriatal dopamine system using an in vitro and in vivo approach. We demonstrate that exposure to HBCDD (0-25 μM) for 24 h causes significant cell death in the SK-N-SH catecholaminergic cell line, as well as reductions in the growth and viability of TH+ primary cultured neurons at lower concentrations (0-10 μM) after 72 h of treatment. Assessment of the in vivo neurotoxicity of HBCDD (25 mg/kg for 30 days) resulted in significant reductions in the expression of the striatal dopamine transporter and vesicular monoamine transporter 2, both of which are integral in mediating dopamine homeostasis and neurotransmission in the dopamine circuit. However, no changes were seen in the expression of tyrosine hydroxylase in the dopamine terminal, or striatal levels of dopamine. To date, these are the first data to demonstrate that exposure to HBCDD disrupts the nigrostriatal dopamine system. Given these results and the ubiquitous nature of HBCDD in the environment, its possible role as an environmental risk factor for PD should be further investigated.
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Affiliation(s)
- Kelly R Genskow
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA 30322-3090, USA
| | - Joshua M Bradner
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA 30322-3090, USA; Center for Neurodegenerative Disease, School of Medicine, Emory University, Atlanta, GA 30322-3090, USA
| | - Muhammad M Hossain
- Department of Environmental and Occupational Medicine, Robert Wood Johnson Medical School Piscataway, NJ 08854, USA
| | - Jason R Richardson
- Department of Environmental and Occupational Medicine, Robert Wood Johnson Medical School Piscataway, NJ 08854, USA
| | - W Michael Caudle
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA 30322-3090, USA; Center for Neurodegenerative Disease, School of Medicine, Emory University, Atlanta, GA 30322-3090, USA.
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Wang X, Yang L, Wu Y, Huang C, Wang Q, Han J, Guo Y, Shi X, Zhou B. The developmental neurotoxicity of polybrominated diphenyl ethers: Effect of DE-71 on dopamine in zebrafish larvae. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2015; 34:1119-1126. [PMID: 25651517 DOI: 10.1002/etc.2906] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Revised: 10/27/2014] [Accepted: 01/21/2015] [Indexed: 06/04/2023]
Abstract
The potential neurotoxicity of polybrominated diphenyl ethers (PBDEs) is still a great concern. In the present study, the authors investigated whether exposure to PBDEs could affect the neurotransmitter system and cause developmental neurotoxicity in zebrafish. Zebrafish embryos (2 h postfertilization) were exposed to different concentrations of the PBDE mixture DE-71 (0-100 μg/L). The larvae were harvested at 120 h postfertilization, and the impact on dopaminergic signaling was investigated. The results revealed significant reductions in content of whole-body dopamine and its metabolite, dihydroxyphenylacetic acid, in DE-71-exposed larvae. The transcription of genes involved in the development of dopaminergic neurons (e.g., manf, bdnf, and nr4a2b) was significantly downregulated upon exposure to DE-71. Also, DE-71 resulted in a significant decrease of tyrosine hydroxylase and dopamine transporter protein levels in dopaminergic neurons. The expression level of tyrosine hydroxylase in forebrain neurons was assessed by whole-mount immunofluorescence, and the results further demonstrated that the tyrosine hydroxylase protein expression level was reduced in dopaminergic neurons. In addition to these molecular changes, the authors observed reduced locomotor activity in DE-71-exposed larvae. Taken together, the results of the present study demonstrate that acute exposure to PBDEs can affect dopaminergic signaling by disrupting the synthesis and transportation of dopamine in zebrafish, thereby disrupting normal neurodevelopment. In accord with its experimental findings, the present study extends knowledge of the mechanisms governing PBDE-induced developmental neurotoxicity.
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Affiliation(s)
- Xianfeng Wang
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China; University of Chinese Academy of Sciences, Beijing, China
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Richardson JR, Taylor MM, Shalat SL, Guillot TS, Caudle WM, Hossain MM, Mathews TA, Jones SR, Cory-Slechta DA, Miller GW. Developmental pesticide exposure reproduces features of attention deficit hyperactivity disorder. FASEB J 2015; 29:1960-72. [PMID: 25630971 DOI: 10.1096/fj.14-260901] [Citation(s) in RCA: 92] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2014] [Accepted: 12/22/2014] [Indexed: 12/25/2022]
Abstract
Attention-deficit hyperactivity disorder (ADHD) is estimated to affect 8-12% of school-age children worldwide. ADHD is a complex disorder with significant genetic contributions. However, no single gene has been linked to a significant percentage of cases, suggesting that environmental factors may contribute to ADHD. Here, we used behavioral, molecular, and neurochemical techniques to characterize the effects of developmental exposure to the pyrethroid pesticide deltamethrin. We also used epidemiologic methods to determine whether there is an association between pyrethroid exposure and diagnosis of ADHD. Mice exposed to the pyrethroid pesticide deltamethrin during development exhibit several features reminiscent of ADHD, including elevated dopamine transporter (DAT) levels, hyperactivity, working memory and attention deficits, and impulsive-like behavior. Increased DAT and D1 dopamine receptor levels appear to be responsible for the behavioral deficits. Epidemiologic data reveal that children aged 6-15 with detectable levels of pyrethroid metabolites in their urine were more than twice as likely to be diagnosed with ADHD. Our epidemiologic finding, combined with the recapitulation of ADHD behavior in pesticide-treated mice, provides a mechanistic basis to suggest that developmental pyrethroid exposure is a risk factor for ADHD.
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Affiliation(s)
- Jason R Richardson
- *Department of Environmental and Occupational Medicine and Environmental and Occupational Health Sciences Institute, Rutgers-Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, New Jersey, USA; Center for Neurodegenerative Disease, School of Medicine, and Department of Environmental and Occupational Health, Rollins School of Public Health, Emory University, Atlanta, Georgia, USA; Department of Physiology and Pharmacology, Wake Forest University Health Sciences, Winston-Salem, North Carolina, USA; Department of Chemistry, Wayne State University, Detroit, Michigan, USA; and Department of Environmental Medicine, University of Rochester Medical Center, Rochester, New York, USA
| | - Michele M Taylor
- *Department of Environmental and Occupational Medicine and Environmental and Occupational Health Sciences Institute, Rutgers-Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, New Jersey, USA; Center for Neurodegenerative Disease, School of Medicine, and Department of Environmental and Occupational Health, Rollins School of Public Health, Emory University, Atlanta, Georgia, USA; Department of Physiology and Pharmacology, Wake Forest University Health Sciences, Winston-Salem, North Carolina, USA; Department of Chemistry, Wayne State University, Detroit, Michigan, USA; and Department of Environmental Medicine, University of Rochester Medical Center, Rochester, New York, USA
| | - Stuart L Shalat
- *Department of Environmental and Occupational Medicine and Environmental and Occupational Health Sciences Institute, Rutgers-Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, New Jersey, USA; Center for Neurodegenerative Disease, School of Medicine, and Department of Environmental and Occupational Health, Rollins School of Public Health, Emory University, Atlanta, Georgia, USA; Department of Physiology and Pharmacology, Wake Forest University Health Sciences, Winston-Salem, North Carolina, USA; Department of Chemistry, Wayne State University, Detroit, Michigan, USA; and Department of Environmental Medicine, University of Rochester Medical Center, Rochester, New York, USA
| | - Thomas S Guillot
- *Department of Environmental and Occupational Medicine and Environmental and Occupational Health Sciences Institute, Rutgers-Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, New Jersey, USA; Center for Neurodegenerative Disease, School of Medicine, and Department of Environmental and Occupational Health, Rollins School of Public Health, Emory University, Atlanta, Georgia, USA; Department of Physiology and Pharmacology, Wake Forest University Health Sciences, Winston-Salem, North Carolina, USA; Department of Chemistry, Wayne State University, Detroit, Michigan, USA; and Department of Environmental Medicine, University of Rochester Medical Center, Rochester, New York, USA
| | - W Michael Caudle
- *Department of Environmental and Occupational Medicine and Environmental and Occupational Health Sciences Institute, Rutgers-Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, New Jersey, USA; Center for Neurodegenerative Disease, School of Medicine, and Department of Environmental and Occupational Health, Rollins School of Public Health, Emory University, Atlanta, Georgia, USA; Department of Physiology and Pharmacology, Wake Forest University Health Sciences, Winston-Salem, North Carolina, USA; Department of Chemistry, Wayne State University, Detroit, Michigan, USA; and Department of Environmental Medicine, University of Rochester Medical Center, Rochester, New York, USA
| | - Muhammad M Hossain
- *Department of Environmental and Occupational Medicine and Environmental and Occupational Health Sciences Institute, Rutgers-Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, New Jersey, USA; Center for Neurodegenerative Disease, School of Medicine, and Department of Environmental and Occupational Health, Rollins School of Public Health, Emory University, Atlanta, Georgia, USA; Department of Physiology and Pharmacology, Wake Forest University Health Sciences, Winston-Salem, North Carolina, USA; Department of Chemistry, Wayne State University, Detroit, Michigan, USA; and Department of Environmental Medicine, University of Rochester Medical Center, Rochester, New York, USA
| | - Tiffany A Mathews
- *Department of Environmental and Occupational Medicine and Environmental and Occupational Health Sciences Institute, Rutgers-Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, New Jersey, USA; Center for Neurodegenerative Disease, School of Medicine, and Department of Environmental and Occupational Health, Rollins School of Public Health, Emory University, Atlanta, Georgia, USA; Department of Physiology and Pharmacology, Wake Forest University Health Sciences, Winston-Salem, North Carolina, USA; Department of Chemistry, Wayne State University, Detroit, Michigan, USA; and Department of Environmental Medicine, University of Rochester Medical Center, Rochester, New York, USA
| | - Sara R Jones
- *Department of Environmental and Occupational Medicine and Environmental and Occupational Health Sciences Institute, Rutgers-Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, New Jersey, USA; Center for Neurodegenerative Disease, School of Medicine, and Department of Environmental and Occupational Health, Rollins School of Public Health, Emory University, Atlanta, Georgia, USA; Department of Physiology and Pharmacology, Wake Forest University Health Sciences, Winston-Salem, North Carolina, USA; Department of Chemistry, Wayne State University, Detroit, Michigan, USA; and Department of Environmental Medicine, University of Rochester Medical Center, Rochester, New York, USA
| | - Deborah A Cory-Slechta
- *Department of Environmental and Occupational Medicine and Environmental and Occupational Health Sciences Institute, Rutgers-Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, New Jersey, USA; Center for Neurodegenerative Disease, School of Medicine, and Department of Environmental and Occupational Health, Rollins School of Public Health, Emory University, Atlanta, Georgia, USA; Department of Physiology and Pharmacology, Wake Forest University Health Sciences, Winston-Salem, North Carolina, USA; Department of Chemistry, Wayne State University, Detroit, Michigan, USA; and Department of Environmental Medicine, University of Rochester Medical Center, Rochester, New York, USA
| | - Gary W Miller
- *Department of Environmental and Occupational Medicine and Environmental and Occupational Health Sciences Institute, Rutgers-Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, New Jersey, USA; Center for Neurodegenerative Disease, School of Medicine, and Department of Environmental and Occupational Health, Rollins School of Public Health, Emory University, Atlanta, Georgia, USA; Department of Physiology and Pharmacology, Wake Forest University Health Sciences, Winston-Salem, North Carolina, USA; Department of Chemistry, Wayne State University, Detroit, Michigan, USA; and Department of Environmental Medicine, University of Rochester Medical Center, Rochester, New York, USA
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Abstract
In recent years, the contribution of exposure to environmental toxicants has been recognized as a significant contributor to the etiopathogenesis of parkinsonism. Of these toxicants, exposure to pesticides, metals, solvents used in manufacturing processes, as well as flame-retardant chemicals used in consumer and commercial products, has received the greatest attention as possible risk factors. Related to this, individuals who are exposed to these compounds at high concentrations or for prolonged periods of time in an occupational setting appear to be one of the more vulnerable populations to these effects. Our understanding of which compounds are involved and the potential molecular pathways that are susceptible to these chemicals and may underlie the pathogenesis has greatly improved. However, there are still hundreds of chemicals that we are exposed to in the environment for which we do not have any information on their potential neurotoxicity on the nigrostriatal dopamine system. Thus, using our past accomplishments as a blueprint, future endeavors should focus on elaborating upon these initial findings in order to identify specific and relevant chemical toxicants in our environment that can impact the risk of parkinsonism and work towards a means to attenuate or abolish their effects on the human population.
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Affiliation(s)
- W Michael Caudle
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA, USA.
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Hajok I, Marchwińska E, Dziubanek G, Kuraszewska B, Piekut A. Environmentally related diseases and the possibility of valuation of their social costs. ScientificWorldJournal 2014; 2014:284072. [PMID: 25374934 PMCID: PMC4211139 DOI: 10.1155/2014/284072] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Accepted: 09/01/2014] [Indexed: 12/02/2022] Open
Abstract
The risks of the morbidity of the asbestos-related lung cancer was estimated in the general population of Poles as the result of increased exposure to asbestos fibers during the removal of asbestos-cement products and the possibility of the valuation of the social costs related to this risk. The prediction of the new incidences was made using linear regression model. The forecast shows that to the end of 2030 about 3,500 new cases of lung cancer can be expected as a result of occupational exposure to asbestos in the past which makes together with paraoccupational exposure about 14.000 new cases. The forecast shows the increasing number of asbestos-related lung cancer in Poland and indicates the priority areas where preventive action should be implemented.
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Affiliation(s)
- Ilona Hajok
- Department of Environmental Health, Faculty of Public Health, Medical University of Silesia in Katowice, Ulica Piekarska 18, 41-902 Bytom, Poland
| | - Ewa Marchwińska
- Department of Environmental Health, Faculty of Public Health, Medical University of Silesia in Katowice, Ulica Piekarska 18, 41-902 Bytom, Poland
| | - Grzegorz Dziubanek
- Department of Environmental Health, Faculty of Public Health, Medical University of Silesia in Katowice, Ulica Piekarska 18, 41-902 Bytom, Poland
| | - Bernadeta Kuraszewska
- Department of Environmental Health, Faculty of Public Health, Medical University of Silesia in Katowice, Ulica Piekarska 18, 41-902 Bytom, Poland
| | - Agata Piekut
- Department of Environmental Health, Faculty of Public Health, Medical University of Silesia in Katowice, Ulica Piekarska 18, 41-902 Bytom, Poland
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Wilson WW, Shapiro LP, Bradner JM, Caudle WM. Developmental exposure to the organochlorine insecticide endosulfan damages the nigrostriatal dopamine system in male offspring. Neurotoxicology 2014; 44:279-87. [PMID: 25092410 PMCID: PMC4175067 DOI: 10.1016/j.neuro.2014.07.008] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2014] [Revised: 07/06/2014] [Accepted: 07/24/2014] [Indexed: 11/22/2022]
Abstract
The contribution of environmental toxicants to the etiology and risk of Parkinson's disease (PD) has been clearly established, with organochlorine insecticides routinely shown to damage the nigrostriatal dopamine pathway. Although PD is generally considered an adult onset disease, it has been postulated that exposure to environmental contaminants or other factors early in life during critical periods of neurodevelopment could alter the dopaminergic circuit and predispose individuals to developing PD. Recent epidemiological evidence has found exposure to the organochlorine insecticide endosulfan to be a risk factor for PD. However, the specific dopaminergic targets or vulnerable developmental time points related to endosulfan exposure have not been investigated. Thus, we sought to investigate dopaminergic neurotoxicity following developmental exposure to endosulfan as well as following an additional challenge with MPTP. Our in vitro findings demonstrate a reduction in SK-N-SH cells and ventral mesencephalic primary cultures after endosulfan treatment. Using an in vivo developmental model, exposure to endosulfan during gestation and lactation caused a reduction in DAT and TH in the striatum of male offspring. These alterations were exacerbated following subsequent treatment with MPTP. In contrast, exposure of adult mice to endosulfan did not elicit dopaminergic damage and did not appear to increase the vulnerability of the dopamine neurons to MPTP. These findings suggest that development during gestation and lactation represents a critical window of susceptibility to endosulfan exposure and development of the nigrostriatal dopamine system. Furthermore, these exposures appear to sensitize the dopamine neurons to additional insults that may occur later in life.
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Affiliation(s)
- W Wyatt Wilson
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA 30322-3090, USA
| | - Lauren P Shapiro
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA 30322-3090, USA
| | - Joshua M Bradner
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA 30322-3090, USA; Center for Neurodegenerative Disease, School of Medicine, Emory University, Atlanta, GA 30322-3090, USA
| | - W Michael Caudle
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA 30322-3090, USA; Center for Neurodegenerative Disease, School of Medicine, Emory University, Atlanta, GA 30322-3090, USA.
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Wilson WW, Onyenwe W, Bradner JM, Nennig SE, Caudle WM. Developmental exposure to the organochlorine insecticide endosulfan alters expression of proteins associated with neurotransmission in the frontal cortex. Synapse 2014; 68:485-97. [PMID: 25042905 DOI: 10.1002/syn.21764] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2013] [Accepted: 06/11/2014] [Indexed: 11/11/2022]
Abstract
Exposure to environmental contaminants, such as organochlorine insecticides during critical periods of neurodevelopment has been shown to be a major contributor to several neuropsychological deficits seen in children, adolescence, and adults. Although the neurobehavioral outcomes resulting from exposure to these compounds are known the neurotransmitter circuitry and molecular targets that mediate these endpoints have not been identified. Given the importance of the frontal cortex in facilitating numerous neuropsychological processes, our current study sought to investigate the effects of developmental exposure to the organochlorine insecticide, endosulfan, on the expression of specific proteins associated with neurotransmission in the frontal cortex. Utilizing in vitro models we were able to show endosulfan reduces cell viability in IMR-32 neuroblastoma cells in addition to reducing synaptic puncta and neurite outgrowth in primary cultured neurons isolated from the frontal cortex of mice. Elaborating these findings to an in vivo model we found that developmental exposure of female mice to endosulfan during gestation and lactation elicited significant alterations to the GABAergic (GAT1, vGAT, GABAA receptor), glutamatergic (vGlut and GluN2B receptor), and dopaminergic (DAT, TH, VMAT2, and D2 receptor) neurotransmitter systems in the frontal cortex of male offspring. These findings identify damage to critical neurotransmitter circuits and proteins in the frontal cortex, which may underlie the neurobehavioral deficits observed following developmental exposure to endosulfan and other organochlorine insecticides.
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Affiliation(s)
- W Wyatt Wilson
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, Georgia, 30322-3090
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Liu HF, Lu S, Ho PWL, Tse HM, Pang SYY, Kung MHW, Ho JWM, Ramsden DB, Zhou ZJ, Ho SL. LRRK2 R1441G mice are more liable to dopamine depletion and locomotor inactivity. Ann Clin Transl Neurol 2014; 1:199-208. [PMID: 25356398 PMCID: PMC4184549 DOI: 10.1002/acn3.45] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2013] [Revised: 01/31/2014] [Accepted: 01/31/2014] [Indexed: 12/11/2022] Open
Abstract
Objective Mutations in leucine-rich repeat kinase 2 (LRRK2) pose a significant genetic risk in familial and sporadic Parkinson's disease (PD). R1441 mutation (R1441G/C) in its GTPase domain is found in familial PD. How LRRK2 interacts with synaptic proteins, and its role in dopamine (DA) homeostasis and synaptic vesicle recycling remain unclear. Methods To explore the pathogenic effects of LRRK2R1441G mutation on nigrostriatal synaptic nerve terminals and locomotor activity, we generated C57BL/6N mice with homozygous LRRK2R1441G knockin (KI) mutation, and examined for early changes in nigrostriatal region, striatal synaptosomal [3H]-DA uptake and locomotor activity after reserpine-induced DA depletion. Results Under normal conditions, mutant mice showed no differences, (1) in amount and morphology of nigrostriatal DA neurons and neurites, (2) tyrosine hydroxylase (TH), DA uptake transporter (DAT), vesicular monoamine transporter-2 (VMAT2) expression in striatum, (3) COX IV, LC3B, Beclin-1 expression in midbrain, (4) LRRK2 expression in total cell lysate from whole brain, (5) α-synuclein, ubiquitin, and tau protein immunostaining in midbrain, (6) locomotor activity, compared to wild-type controls. However, after a single intraperitoneal reserpine dose, striatal synaptosomes from young 3-month-old mutant mice demonstrated significantly lower DA uptake with impaired locomotor activity and significantly slower recovery from the effects of reserpine. Interpretation Although no abnormal phenotype was observed in mutant LRRK2R1441G mice, the KI mutation increases vulnerability to reserpine-induced striatal DA depletion and perturbed DA homeostasis resulting in presynaptic dysfunction and locomotor deficits with impaired recovery from reserpine. This subtle nigrostriatal synaptic vulnerability may reflect one of the earliest pathogenic processes in LRRK2-associated PD.
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Affiliation(s)
- Hui-Fang Liu
- Division of Neurology, Department of Medicine, University of Hong Kong Hong Kong
| | - Song Lu
- Division of Neurology, Department of Medicine, University of Hong Kong Hong Kong ; Research Centre of Heart, Brain, Hormone and Healthy Aging, University of Hong Kong Hong Kong
| | - Philip Wing-Lok Ho
- Division of Neurology, Department of Medicine, University of Hong Kong Hong Kong ; Research Centre of Heart, Brain, Hormone and Healthy Aging, University of Hong Kong Hong Kong
| | - Ho-Man Tse
- Division of Neurology, Department of Medicine, University of Hong Kong Hong Kong
| | - Shirley Yin-Yu Pang
- Division of Neurology, Department of Medicine, University of Hong Kong Hong Kong
| | | | - Jessica Wing-Man Ho
- Division of Neurology, Department of Medicine, University of Hong Kong Hong Kong ; Research Centre of Heart, Brain, Hormone and Healthy Aging, University of Hong Kong Hong Kong
| | - David B Ramsden
- Department of Clinical and Experimental Medicine, University of Birmingham Birmingham, United Kingdom
| | - Zhong-Jun Zhou
- Department of Biochemistry, University of Hong Kong Hong Kong
| | - Shu-Leong Ho
- Division of Neurology, Department of Medicine, University of Hong Kong Hong Kong ; Research Centre of Heart, Brain, Hormone and Healthy Aging, University of Hong Kong Hong Kong
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Bernstein AI, Stout KA, Miller GW. The vesicular monoamine transporter 2: an underexplored pharmacological target. Neurochem Int 2014; 73:89-97. [PMID: 24398404 DOI: 10.1016/j.neuint.2013.12.003] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2013] [Revised: 12/06/2013] [Accepted: 12/09/2013] [Indexed: 12/21/2022]
Abstract
Active transport of neurotransmitters into synaptic vesicles is required for their subsequent exocytotic release. In the monoamine system, this process is carried out by the vesicular monoamine transporters (VMAT1 and VMAT2). These proteins are responsible for vesicular packaging of dopamine, norepinephrine, serotonin, and histamine. These proteins are essential for proper neuronal function; however, compared to their plasma membrane counterparts, there are few drugs available that target these vesicular proteins. This is partly due to the added complexity of crossing the plasma membrane, but also to the technical difficulty of assaying for vesicular uptake in high throughput. Until recently, reagents to enable high throughput screening for function of these vesicular neurotransmitter transporters have not been available. Fortunately, novel compounds and methods are now making such screening possible; thus, a renewed focus on these transporters as potential targets is timely and necessary.
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Affiliation(s)
- Alison I Bernstein
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA 30322, USA
| | - Kristen A Stout
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA 30322, USA
| | - Gary W Miller
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA 30322, USA; Center for Neurodegenerative Diseases, Emory University, Atlanta, GA 30322, USA; Department of Pharmacology, Emory University, Atlanta, GA 30322, USA; Department of Neurology, Emory University, Atlanta, GA 30322, USA.
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45
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Taylor TN, Alter SP, Wang M, Goldstein DS, Miller GW. Reduced vesicular storage of catecholamines causes progressive degeneration in the locus ceruleus. Neuropharmacology 2014; 76 Pt A:97-105. [PMID: 24025942 PMCID: PMC4049095 DOI: 10.1016/j.neuropharm.2013.08.033] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Revised: 08/23/2013] [Accepted: 08/26/2013] [Indexed: 10/26/2022]
Abstract
Parkinson's disease (PD) is the most common neurodegenerative motor disease. Pathologically, PD is characterized by Lewy body deposition and subsequent death of dopamine neurons in the substantia nigra pars compacta. PD also consistently features degeneration of the locus ceruleus, the main source of norepinephrine in the central nervous system. We have previously reported a mouse model of dopaminergic neurodegeneration based on reduced expression of the vesicular monoamine transporter (VMAT2 LO). To determine if reduced vesicular storage can also cause noradrenergic degeneration, we examined indices of damage to the catecholaminergic systems in brain and cardiac tissue of VMAT2 LO mice. At two months of age, neurochemical analyses revealed substantial reductions in striatal dopamine (94%), cortical dopamine (57%) and norepinephrine (54%), as well as cardiac norepinephrine (97%). These losses were accompanied by increased conversion of dopamine and norepinephrine to their deaminated metabolites. VMAT2 LO mice exhibited loss of noradrenergic innervation in the cortex, as determined by norepinephrine transporter immunoreactivity and (3)H-nisoxetine binding. Using unbiased stereological techniques, we observed progressive degeneration in the locus ceruleus that preceded degeneration of the substantia nigra pars compacta. In contrast, the ventral tegmental area, which is spared in human PD, remained unaffected. The coordinate loss of dopamine and norepinephrine neurons in VMAT2 LO mice parallels the pattern of neurodegeneration that occurs in human PD, and demonstrates that insufficient catecholamine storage can cause spontaneous degeneration in susceptible neurons, underscoring cytosolic catecholamine catabolism as a determinant of neuronal susceptibility in PD. This article is part of the Special Issue entitled 'The Synaptic Basis of Neurodegenerative Disorders'.
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Affiliation(s)
- Tonya N. Taylor
- Center for Neurodegenerative Disease, Emory University, Atlanta, GA
- Department of Environmental Health, Emory University, Atlanta, GA
| | - Shawn P. Alter
- Center for Neurodegenerative Disease, Emory University, Atlanta, GA
- Department of Environmental Health, Emory University, Atlanta, GA
| | - Minzheng Wang
- Center for Neurodegenerative Disease, Emory University, Atlanta, GA
- Department of Environmental Health, Emory University, Atlanta, GA
| | | | - Gary W. Miller
- Center for Neurodegenerative Disease, Emory University, Atlanta, GA
- Department of Environmental Health, Emory University, Atlanta, GA
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Wigestrand M, Stenberg M, Walaas S, Fonnum F, Andersson P. Non-dioxin-like PCBs inhibit [3H]WIN-35,428 binding to the dopamine transporter: A structure–activity relationship study. Neurotoxicology 2013; 39:18-24. [DOI: 10.1016/j.neuro.2013.07.005] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2013] [Revised: 07/24/2013] [Accepted: 07/24/2013] [Indexed: 11/29/2022]
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Adornetto A, Pagliara V, Renzo GD, Arcone R. Polychlorinated biphenyls impair dibutyryl cAMP-induced astrocytic differentiation in rat C6 glial cell line. FEBS Open Bio 2013; 3:459-66. [PMID: 24251112 PMCID: PMC3829991 DOI: 10.1016/j.fob.2013.10.008] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2013] [Revised: 10/20/2013] [Accepted: 10/22/2013] [Indexed: 02/04/2023] Open
Abstract
In the central nervous system, alteration of glial cell differentiation can affect brain functions. Polychlorinated biphenyls (PCBs) are persistent environmental chemical contaminants that exert neurotoxic effects in glial and neuronal cells. We examined the effects of a commercial mixture of PCBs, Aroclor1254 (A1254) on astrocytic differentiation of glial cells, using the rat C6 cell line as in vitro model. The exposure for 24 h to sub-toxic concentrations of A1254 (3 or 9 μM) impaired dibutyryl cAMP-induced astrocytic differentiation as showed by the decrease of glial fibrillary acidic protein (GFAP) protein levels and inhibition in change of cell morphology toward an astrocytic phenotype. The A1254 inhibition was restored by the addition of a protein kinase C (PKC) inhibitor, bisindolylmaleimide (bis), therefore indicating that PCBs disturbed the cAMP-induced astrocytic differentiation of C6 cells via the PKC pathway. The phosphorylation of signal transducer and activator of transcription 3 (STAT3) is essential for cAMP-induced transcription of GFAP promoter in C6 cells. Our results indicated that the exposure to A1254 (3 or 9 μM) for 24 h suppressed cAMP-induced STAT3 phosphorylation. Moreover, A1254 reduced cAMP-dependent phosphorylation of STAT3 requires inhibition of PKC activity. Together, our results suggest that PCBs induce perturbation in cAMP/PKA and PKC signaling pathway during astrocytic differentiation of glial cells.
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Key Words
- A1254, Aroclor 1254
- Aroclor1254
- Astrocytic differentiation
- C6 glial cell line
- CNS, central nervous system
- CRE, cAMP responsive element
- CREB, cAMP-response element binding protein
- DAPI, 4′,6-diamidino-2-phenylindole
- DMEM, Dulbecco’s Modified Eagle’s Medium
- DMSO, dimethyl sulfoxide
- GAPDH, glyceraldehyde-3-phosphate dehydrogenase
- GFAP, glial fibrillary acidic protein
- Glial fibrillary acidic protein (GFAP)
- MTT, 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide
- NMDA, N-methyl-d-aspartate
- PCBs, polychlorinated biphenyls
- PKA, protein kinase A
- PKC, protein kinase C
- Protein kinase C (PKC)
- ROS, reactive oxygen species
- STAT3, signal transducer and activator of transcription 3
- Signal transducer and activator of transcription 3 (STAT3)
- TRE, CRE transcriptional response element
- bis, 2-[1-(3-dimethylamino-propyl)indol-3-yl]-3-(indol-3-yl) maleimide
- dbcAMP, N6,2′-O-dibutyryl cAMP
- nNOS, neuronal nitric oxide
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Affiliation(s)
- Annagrazia Adornetto
- Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, Via P. Bucci, Arcavacata di Rende, Cosenza (CS) 87036, Italy
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48
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Taylor TN, Potgieter D, Anwar S, Senior SL, Janezic S, Threlfell S, Ryan B, Parkkinen L, Deltheil T, Cioroch M, Livieratos A, Oliver PL, Jennings KA, Davies KE, Ansorge O, Bannerman DM, Cragg SJ, Wade-Martins R. Region-specific deficits in dopamine, but not norepinephrine, signaling in a novel A30P α-synuclein BAC transgenic mouse. Neurobiol Dis 2013; 62:193-207. [PMID: 24121116 PMCID: PMC3898275 DOI: 10.1016/j.nbd.2013.10.005] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2013] [Revised: 09/09/2013] [Accepted: 10/02/2013] [Indexed: 12/15/2022] Open
Abstract
Parkinson's disease (PD) is a neurodegenerative disorder classically characterized by the death of dopamine (DA) neurons in the substantia nigra pars compacta and by intracellular Lewy bodies composed largely of α-synuclein. Approximately 5–10% of PD patients have a familial form of Parkinsonism, including mutations in α-synuclein. To better understand the cell-type specific role of α-synuclein on DA neurotransmission, and the effects of the disease-associated A30P mutation, we generated and studied a novel transgenic model of PD. We expressed the A30P mutant form of human α-synuclein in a spatially-relevant manner from the 111 kb SNCA genomic DNA locus on a bacterial artificial chromosome (BAC) insert on a mouse null (Snca −/−) background. The BAC transgenic mice expressed α-synuclein in tyrosine hydroxylase-positive neurons and expression of either A30P α-synuclein or wildtype α-synuclein restored the sensitivity of DA neurons to MPTP in resistant Snca −/− animals. A30P α-synuclein mice showed no Lewy body-like aggregation, and did not lose catecholamine neurons in substantia nigra or locus coeruleus. However, using cyclic voltammetry at carbon-fiber microelectrodes we identified a deficit in evoked DA release in the caudate putamen, but not in the nucleus accumbens, of SNCA-A30P Snca −/− mice but no changes to release of another catecholamine, norepinephrine (NE), in the NE-rich ventral bed nucleus of stria terminalis. SNCA-A30P Snca −/− mice had no overt behavioral impairments but exhibited a mild increase in wheel-running. In summary, this refined PD mouse model shows that A30P α-synuclein preferentially perturbs the dopaminergic system in the dorsal striatum, reflecting the region-specific change seen in PD. SNCA A30P BAC transgenic mice recapitulate endogenous α-synuclein expression pattern SNCA A30P BAC transgenic mice demonstrate a region specific deficit in evoked DA, but not NE, release. Expression of A30P or WT α-syn restored the sensitivity of DA neurons to MPTP. A30P BAC mice had no Lewy body-like aggregation or neuronal loss in SNpc or LC. Early changes in DA neurotransmission in the absence of aggregation
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Affiliation(s)
- Tonya N Taylor
- Oxford Parkinson's Disease Centre, University of Oxford, Oxford, UK; Department of Physiology, Anatomy, and Genetics, University of Oxford, Oxford, UK
| | - Dawid Potgieter
- Oxford Parkinson's Disease Centre, University of Oxford, Oxford, UK; Department of Physiology, Anatomy, and Genetics, University of Oxford, Oxford, UK
| | - Sabina Anwar
- Oxford Parkinson's Disease Centre, University of Oxford, Oxford, UK; Department of Physiology, Anatomy, and Genetics, University of Oxford, Oxford, UK
| | - Steven L Senior
- Oxford Parkinson's Disease Centre, University of Oxford, Oxford, UK; Department of Physiology, Anatomy, and Genetics, University of Oxford, Oxford, UK
| | - Stephanie Janezic
- Oxford Parkinson's Disease Centre, University of Oxford, Oxford, UK; Department of Physiology, Anatomy, and Genetics, University of Oxford, Oxford, UK
| | - Sarah Threlfell
- Oxford Parkinson's Disease Centre, University of Oxford, Oxford, UK; Department of Physiology, Anatomy, and Genetics, University of Oxford, Oxford, UK
| | - Brent Ryan
- Oxford Parkinson's Disease Centre, University of Oxford, Oxford, UK; Department of Physiology, Anatomy, and Genetics, University of Oxford, Oxford, UK
| | - Laura Parkkinen
- Oxford Parkinson's Disease Centre, University of Oxford, Oxford, UK; Nuffield Department of Clinical Neuroscience, John Radcliffe Hospital, University of Oxford, Oxford, UK
| | - Thierry Deltheil
- Oxford Parkinson's Disease Centre, University of Oxford, Oxford, UK; Department of Physiology, Anatomy, and Genetics, University of Oxford, Oxford, UK
| | - Milena Cioroch
- Oxford Parkinson's Disease Centre, University of Oxford, Oxford, UK; Department of Physiology, Anatomy, and Genetics, University of Oxford, Oxford, UK
| | - Achilleas Livieratos
- Department of Physiology, Anatomy, and Genetics, University of Oxford, Oxford, UK; MRC Functional Genomics Unit, University of Oxford, Oxford, UK
| | - Peter L Oliver
- Department of Physiology, Anatomy, and Genetics, University of Oxford, Oxford, UK; MRC Functional Genomics Unit, University of Oxford, Oxford, UK
| | - Katie A Jennings
- Oxford Parkinson's Disease Centre, University of Oxford, Oxford, UK; Department of Physiology, Anatomy, and Genetics, University of Oxford, Oxford, UK
| | - Kay E Davies
- Department of Physiology, Anatomy, and Genetics, University of Oxford, Oxford, UK; MRC Functional Genomics Unit, University of Oxford, Oxford, UK
| | - Olaf Ansorge
- Oxford Parkinson's Disease Centre, University of Oxford, Oxford, UK; Nuffield Department of Clinical Neuroscience, John Radcliffe Hospital, University of Oxford, Oxford, UK
| | - David M Bannerman
- Oxford Parkinson's Disease Centre, University of Oxford, Oxford, UK; Department of Experimental Psychology, University of Oxford, Oxford, UK
| | - Stephanie J Cragg
- Oxford Parkinson's Disease Centre, University of Oxford, Oxford, UK; Department of Physiology, Anatomy, and Genetics, University of Oxford, Oxford, UK
| | - Richard Wade-Martins
- Oxford Parkinson's Disease Centre, University of Oxford, Oxford, UK; Department of Physiology, Anatomy, and Genetics, University of Oxford, Oxford, UK.
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Selvakumar K, Bavithra S, Ganesh L, Krishnamoorthy G, Venkataraman P, Arunakaran J. Polychlorinated biphenyls induced oxidative stress mediated neurodegeneration in hippocampus and behavioral changes of adult rats: Anxiolytic-like effects of quercetin. Toxicol Lett 2013; 222:45-54. [DOI: 10.1016/j.toxlet.2013.06.237] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2013] [Revised: 06/20/2013] [Accepted: 06/27/2013] [Indexed: 12/26/2022]
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50
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The dynamics of autism spectrum disorders: how neurotoxic compounds and neurotransmitters interact. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2013; 10:3384-408. [PMID: 23924882 PMCID: PMC3774444 DOI: 10.3390/ijerph10083384] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 07/01/2013] [Revised: 07/23/2013] [Accepted: 07/23/2013] [Indexed: 12/31/2022]
Abstract
In recent years concern has risen about the increasing prevalence of Autism Spectrum Disorders (ASD). Accumulating evidence shows that exposure to neurotoxic compounds is related to ASD. Neurotransmitters might play a key role, as research has indicated a connection between neurotoxic compounds, neurotransmitters and ASD. In the current review a literature overview with respect to neurotoxic exposure and the effects on neurotransmitter systems is presented. The aim was to identify mechanisms and related factors which together might result in ASD. The literature reported in the current review supports the hypothesis that exposure to neurotoxic compounds can lead to alterations in the GABAergic, glutamatergic, serotonergic and dopaminergic system which have been related to ASD in previous work. However, in several studies findings were reported that are not supportive of this hypothesis. Other factors also might be related, possibly altering the mechanisms at work, such as time and length of exposure as well as dose of the compound. Future research should focus on identifying the pathway through which these factors interact with exposure to neurotoxic compounds making use of human studies.
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