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Dorman DC. The Role of Oxidative Stress in Manganese Neurotoxicity: A Literature Review Focused on Contributions Made by Professor Michael Aschner. Biomolecules 2023; 13:1176. [PMID: 37627240 PMCID: PMC10452838 DOI: 10.3390/biom13081176] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Revised: 07/21/2023] [Accepted: 07/26/2023] [Indexed: 08/27/2023] Open
Abstract
This literature review focuses on the evidence implicating oxidative stress in the pathogenesis of manganese neurotoxicity. This review is not intended to be a systematic review of the relevant toxicologic literature. Instead, in keeping with the spirit of this special journal issue, this review highlights contributions made by Professor Michael Aschner's laboratory in this field of study. Over the past two decades, his laboratory has made significant contributions to our scientific understanding of cellular responses that occur both in vitro and in vivo following manganese exposure. These studies have identified molecular targets of manganese toxicity and their respective roles in mitochondrial dysfunction, inflammation, and cytotoxicity. Other studies have focused on the critical role astrocytes play in manganese neurotoxicity. Recent studies from his laboratory have used C. elegans to discover new facets of manganese-induced neurotoxicity. Collectively, his body of work has dramatically advanced the field and presents broader implications beyond metal toxicology.
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Affiliation(s)
- David C Dorman
- Department of Molecular Biomedical Sciences, College of Veterinary Medicine, North Carolina State University, 1052 William Moore Dr, Raleigh, NC 27606, USA
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Wilcox JM, Pfalzer AC, Tienda AA, Debbiche IF, Cox EC, Totten MS, Erikson KM, Harrison FE, Bowman AB. YAC128 mouse model of Huntington disease is protected against subtle chronic manganese (Mn)-induced behavioral and neuropathological changes. Neurotoxicology 2021; 87:94-105. [PMID: 34543681 PMCID: PMC8761387 DOI: 10.1016/j.neuro.2021.09.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Revised: 08/27/2021] [Accepted: 09/15/2021] [Indexed: 01/08/2023]
Abstract
Manganese (Mn) is an essential micronutrient but excessive levels induce neurotoxic effects. Increasing evidence suggests a deficit of bioavailable Mn in Huntington disease (HD), an inherited neurodegenerative disease characterized by motor and cognitive disturbances. Previous studies have shown rescue of some molecular HD phenotypes by acute Mn exposure. This study simultaneously examined the potential for chronic Mn exposure to attenuate HD behavioral phenotypes, and for the HD genotype to offer protection against detrimental effects of chronic Mn exposure. In two independent studies a chronic Mn exposure paradigm was implemented in the YAC128 mouse model of HD and behavior was assessed at several timepoints. Study 1 exposed WT and YAC128 mice to twice weekly subcutaneous injections of 0, 5, 15, or 50 mg/kg MnCl[2] tetrahydrate from 12 to 32 weeks of age. A promising protective effect against motor coordination decline in 5 mg/kg MnCl[2] tetrahydrate-treated YAC128 mice was detected. Study 2 thus exposed WT and YAC128 mice to either 0 or 5 mg/kg MnCl[2] tetrahydrate from 12 to 52 weeks of age (with a partial randomized treatment crossover at 31 weeks). The same protective effect was not observed under these conditions at higher statistical power. We report subtle toxicological changes in exploratory behavior and total activity induced by chronic Mn exposure in WT mice only, despite similar total increases in brain Mn in WT and YAC128 mice. Further, chronic Mn treatment resulted in a 10-12 % decrease in striatal NeuN positive cell density in WT mice but not YAC128 mice, despite vehicle cell counts already being reduced compared to WT mice as expected for the HD genotype. The subtle changes observed in specific outcome measures, but not others, following long-term low-level Mn exposure in WT mice delineate the neurobehavioral and neuropathological effects at the threshold of chronic Mn toxicity. We conclude that these chronic low-dose Mn exposures do not significantly rescue behavioral HD phenotypes, but YAC2128 mice are protected against the subtle Mn-induced behavioral changes and decreased striatal neuron density observed in Mn-exposed WT mice.
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Affiliation(s)
- Jordyn M Wilcox
- Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, United States; Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN, United States
| | - Anna C Pfalzer
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Adriana A Tienda
- Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Ines F Debbiche
- Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN, United States
| | - Ellen C Cox
- Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Melissa S Totten
- Department of Nutrition, University of North Carolina-Greensboro, Greensboro, NC, United States
| | - Keith M Erikson
- Department of Nutrition, University of North Carolina-Greensboro, Greensboro, NC, United States
| | - Fiona E Harrison
- Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, United States; Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN, United States
| | - Aaron B Bowman
- School of Health Sciences, Purdue University, West Lafayette, IN, United States.
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Zhang K, He K, Xu J, Nie L, Li S, Liu J, Long D, Dai Z, Yang X. Manganese exposure causes movement deficit and changes in the protein profile of the external globus pallidus in Sprague Dawley rats. Toxicol Ind Health 2021; 37:715-726. [PMID: 34706592 DOI: 10.1177/07482337211022223] [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] [Indexed: 11/17/2022]
Abstract
Manganese (Mn) is required for normal brain development and function. Excess Mn may trigger a parkinsonian movement disorder but the underlying mechanisms are incompletely understood. We explored changes in the brain proteomic profile and movement behavior of adult Sprague Dawley (SD) rats systemically treated with or without 1.0 mg/mL MnCl2 for 3 months. Mn treatment significantly increased the concentration of protein-bound Mn in the external globus pallidus (GP), as demonstrated by inductively coupled plasma mass spectrometry. Behavioral study showed that Mn treatment induced movement deficits, especially of skilled movement. Proteome analysis by two-dimensional fluorescence difference gel electrophoresis coupled with mass spectrometry revealed 13 differentially expressed proteins in the GP of Mn-treated versus Mn-untreated SD rats. The differentially expressed proteins were mostly involved in glycolysis, metabolic pathways, and response to hypoxia. Selected pathway class analysis of differentially expressed GP proteins, which included phosphoglycerate mutase 1 (PGAM1), primarily identified enrichment in glycolytic process and innate immune response. In conclusion, perturbation of brain energy production and innate immune response, in which PGAM1 has key roles, may contribute to the movement disorder associated with Mn neurotoxicity.
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Affiliation(s)
- Kaiqin Zhang
- School of Public Health, University of South China, Hunan Hengyang, China.,Key Laboratory of Modern Toxicology of Shenzhen, Shenzhen Medical Key Discipline of Health Toxicology, Shenzhen Center for Disease Control and Prevention, Shenzhen, China
| | - Kaiwu He
- Key Laboratory of Modern Toxicology of Shenzhen, Shenzhen Medical Key Discipline of Health Toxicology, Shenzhen Center for Disease Control and Prevention, Shenzhen, China.,School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen, China
| | - Jia Xu
- Key Laboratory of Modern Toxicology of Shenzhen, Shenzhen Medical Key Discipline of Health Toxicology, Shenzhen Center for Disease Control and Prevention, Shenzhen, China
| | - Lulin Nie
- Key Laboratory of Modern Toxicology of Shenzhen, Shenzhen Medical Key Discipline of Health Toxicology, Shenzhen Center for Disease Control and Prevention, Shenzhen, China
| | - Shupeng Li
- School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen, China
| | - Jianjun Liu
- Key Laboratory of Modern Toxicology of Shenzhen, Shenzhen Medical Key Discipline of Health Toxicology, Shenzhen Center for Disease Control and Prevention, Shenzhen, China
| | - Dingxin Long
- School of Public Health, University of South China, Hunan Hengyang, China
| | - Zhongliang Dai
- The department of Anesthesiology, Shenzhen People's Hospital, The Second Clinical Medical College, Jinan University, Shenzhen, China
| | - Xifei Yang
- Key Laboratory of Modern Toxicology of Shenzhen, Shenzhen Medical Key Discipline of Health Toxicology, Shenzhen Center for Disease Control and Prevention, Shenzhen, China
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Pajarillo E, Nyarko-Danquah I, Adinew G, Rizor A, Aschner M, Lee E. Neurotoxicity mechanisms of manganese in the central nervous system. ADVANCES IN NEUROTOXICOLOGY 2021; 5:215-238. [PMID: 34263091 DOI: 10.1016/bs.ant.2020.11.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Edward Pajarillo
- Department of Pharmaceutical Sciences, Florida A&M University, Tallahassee, FL, United States
| | - Ivan Nyarko-Danquah
- Department of Pharmaceutical Sciences, Florida A&M University, Tallahassee, FL, United States
| | - Getinet Adinew
- Department of Pharmaceutical Sciences, Florida A&M University, Tallahassee, FL, United States
| | - Asha Rizor
- Department of Pharmaceutical Sciences, Florida A&M University, Tallahassee, FL, United States
| | - Michael Aschner
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY, United States
| | - Eunsook Lee
- Department of Pharmaceutical Sciences, Florida A&M University, Tallahassee, FL, United States
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Freeman DM, O'Neal R, Zhang Q, Bouwer EJ, Wang Z. Manganese-induced Parkinsonism in mice is reduced using a novel contaminated water sediment exposure model. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2020; 78:103399. [PMID: 32380377 DOI: 10.1016/j.etap.2020.103399] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 04/15/2020] [Accepted: 04/18/2020] [Indexed: 06/11/2023]
Abstract
Heavy metals enter the aquatic environment and accumulate within water sediments, but these metal-sediment interactions remain to be explored within toxicity studies. We developed an exposure model in mice that encapsulates the aquatic microenvironment of metals before exposure. Male and female C57/BL6 mice were exposed via their drinking water to manganese contaminated sediment (Sed_Mn) or to manganese without sediment interaction (Mn) for six weeks. Sediment interaction did not alter weekly manganese ingestion from water in males or females. We analyzed motor impairment, a common feature in manganese-induced Parkinsonism, using the beam traversal, cylinder, and accelerating rotarod tests. Sed_Mn mice performed better overall compared to Mn mice and males were more sensitive to manganese than females in both Sed_Mn and Mn treatment groups. Our study indicates that metal-sediment interactions may alter metal toxicity in mammals and introduces a new exposure model to test the toxicity of metal contaminants of drinking water.
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Affiliation(s)
- Dana M Freeman
- Department of Environmental Health & Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Rachel O'Neal
- Department of Environmental Health & Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Qiang Zhang
- Department of Environmental Health & Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Edward J Bouwer
- Department of Environmental Health & Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Zhibin Wang
- Department of Environmental Health & Engineering, Johns Hopkins University, Baltimore, MD, USA.
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Pajarillo E, Rizor A, Son DS, Aschner M, Lee E. The transcription factor REST up-regulates tyrosine hydroxylase and antiapoptotic genes and protects dopaminergic neurons against manganese toxicity. J Biol Chem 2020; 295:3040-3054. [PMID: 32001620 PMCID: PMC7062174 DOI: 10.1074/jbc.ra119.011446] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Revised: 01/22/2020] [Indexed: 12/13/2022] Open
Abstract
Dopaminergic functions are important for various biological activities, and their impairment leads to neurodegeneration, a hallmark of Parkinson's disease (PD). Chronic manganese (Mn) exposure causes the neurological disorder manganism, presenting symptoms similar to those of PD. Emerging evidence has linked the transcription factor RE1-silencing transcription factor (REST) to PD and also Alzheimer's disease. But REST's role in dopaminergic neurons is unclear. Here, we investigated whether REST protects dopaminergic neurons against Mn-induced toxicity and enhances expression of the dopamine-synthesizing enzyme tyrosine hydroxylase (TH). We report that REST binds to RE1 consensus sites in the TH gene promoter, stimulates TH transcription, and increases TH mRNA and protein levels in dopaminergic cells. REST binding to the TH promoter recruited the epigenetic modifier cAMP-response element-binding protein-binding protein/p300 and thereby up-regulated TH expression. REST relieved Mn-induced repression of TH promoter activity, mRNA, and protein levels and also reduced Mn-induced oxidative stress, inflammation, and apoptosis in dopaminergic neurons. REST reduced Mn-induced proinflammatory cytokines, including tumor necrosis factor α, interleukin 1β (IL-1β), IL-6, and interferon γ. Moreover, REST inhibited the Mn-induced proapoptotic proteins Bcl-2-associated X protein (Bax) and death-associated protein 6 (Daxx) and attenuated an Mn-induced decrease in the antiapoptotic proteins Bcl-2 and Bcl-xL. REST also enhanced the expression of antioxidant proteins, including catalase, NF-E2-related factor 2 (Nrf2), and heme oxygenase 1 (HO-1). Our findings indicate that REST activates TH expression and thereby protects neurons against Mn-induced toxicity and neurological disorders associated with dopaminergic neurodegeneration.
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Affiliation(s)
- Edward Pajarillo
- Department of Pharmaceutical Sciences, Florida A&M University, Tallahassee, Florida 32301
| | - Asha Rizor
- Department of Pharmaceutical Sciences, Florida A&M University, Tallahassee, Florida 32301
| | - Deok-Soo Son
- Department of Biochemistry and Cancer Biology, Meharry Medical College, Nashville, Tennessee 37208
| | - Michael Aschner
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, New York, New York 10461
| | - Eunsook Lee
- Department of Pharmaceutical Sciences, Florida A&M University, Tallahassee, Florida 32301.
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Cavey T, Latour C, Island ML, Leroyer P, Guggenbuhl P, Coppin H, Roth MP, Bendavid C, Brissot P, Ropert M, Loréal O. Spleen iron, molybdenum, and manganese concentrations are coregulated in hepcidin‐deficient and secondary iron overload models in mice. FASEB J 2019; 33:11072-11081. [DOI: 10.1096/fj.201801381rr] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Thibault Cavey
- INSERMUniversité RennesINRAUMR 1241Analyse Elémentaire et Métabolisme des Métaux (AEM2) PlatformCHU Pontchaillou, NutritionMétabolismes et Cancer Institute (NuMeCan)RennesFrance
| | - Chloé Latour
- Institut de Recherche en Santé Digestive (IRSD)INSERMINRAÉcole Nationale Vétérinaire de Toulouse (ENVT)Université Paul Sabatier (UPS)-Université de ToulouseToulouseFrance
| | - Marie-Laure Island
- INSERMUniversité RennesINRAUMR 1241Analyse Elémentaire et Métabolisme des Métaux (AEM2) PlatformCHU Pontchaillou, NutritionMétabolismes et Cancer Institute (NuMeCan)RennesFrance
| | - Patricia Leroyer
- INSERMUniversité RennesINRAUMR 1241Analyse Elémentaire et Métabolisme des Métaux (AEM2) PlatformCHU Pontchaillou, NutritionMétabolismes et Cancer Institute (NuMeCan)RennesFrance
| | - Pascal Guggenbuhl
- INSERMUniversité RennesINRAUMR 1241Analyse Elémentaire et Métabolisme des Métaux (AEM2) PlatformCHU Pontchaillou, NutritionMétabolismes et Cancer Institute (NuMeCan)RennesFrance
| | - Hélène Coppin
- Institut de Recherche en Santé Digestive (IRSD)INSERMINRAÉcole Nationale Vétérinaire de Toulouse (ENVT)Université Paul Sabatier (UPS)-Université de ToulouseToulouseFrance
| | - Marie-Paule Roth
- Institut de Recherche en Santé Digestive (IRSD)INSERMINRAÉcole Nationale Vétérinaire de Toulouse (ENVT)Université Paul Sabatier (UPS)-Université de ToulouseToulouseFrance
| | - Claude Bendavid
- INSERMUniversité RennesINRAUMR 1241Analyse Elémentaire et Métabolisme des Métaux (AEM2) PlatformCHU Pontchaillou, NutritionMétabolismes et Cancer Institute (NuMeCan)RennesFrance
| | - Pierre Brissot
- INSERMUniversité RennesINRAUMR 1241Analyse Elémentaire et Métabolisme des Métaux (AEM2) PlatformCHU Pontchaillou, NutritionMétabolismes et Cancer Institute (NuMeCan)RennesFrance
| | - Martine Ropert
- INSERMUniversité RennesINRAUMR 1241Analyse Elémentaire et Métabolisme des Métaux (AEM2) PlatformCHU Pontchaillou, NutritionMétabolismes et Cancer Institute (NuMeCan)RennesFrance
| | - Olivier Loréal
- INSERMUniversité RennesINRAUMR 1241Analyse Elémentaire et Métabolisme des Métaux (AEM2) PlatformCHU Pontchaillou, NutritionMétabolismes et Cancer Institute (NuMeCan)RennesFrance
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Ye Q, Park JE, Gugnani K, Betharia S, Pino-Figueroa A, Kim J. Influence of iron metabolism on manganese transport and toxicity. Metallomics 2017; 9:1028-1046. [PMID: 28620665 DOI: 10.1039/c7mt00079k] [Citation(s) in RCA: 74] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Although manganese (Mn) is critical for the proper functioning of various metabolic enzymes and cofactors, excess Mn in the brain causes neurotoxicity. While the exact transport mechanism of Mn has not been fully understood, several importers and exporters for Mn have been identified over the past decade. In addition to Mn-specific transporters, it has been demonstrated that iron transporters can mediate Mn transport in the brain and peripheral tissues. However, while the expression of iron transporters is regulated by body iron stores, whether or not disorders of iron metabolism modify Mn homeostasis has not been systematically discussed. The present review will provide an update on the role of altered iron status in the transport and toxicity of Mn.
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Affiliation(s)
- Qi Ye
- Department of Pharmaceutical Sciences, Northeastern University, 360 Huntington Avenue 148TF, Boston, MA 02115, USA.
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Sukumaran A, Chang J, Han M, Mintri S, Khaw BA, Kim J. Iron overload exacerbates age-associated cardiac hypertrophy in a mouse model of hemochromatosis. Sci Rep 2017; 7:5756. [PMID: 28720890 PMCID: PMC5516030 DOI: 10.1038/s41598-017-05810-2] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Accepted: 06/02/2017] [Indexed: 12/12/2022] Open
Abstract
Cardiac damage associated with iron overload is the most common cause of morbidity and mortality in patients with hereditary hemochromatosis, but the precise mechanisms leading to disease progression are largely unexplored. Here we investigated the effects of iron overload and age on cardiac hypertrophy using 1-, 5- and 12-month old Hfe-deficient mice, an animal model of hemochromatosis in humans. Cardiac iron levels increased progressively with age, which was exacerbated in Hfe-deficient mice. The heart/body weight ratios were greater in Hfe-deficient mice at 5- and 12-month old, compared with their age-matched wild-type controls. Cardiac hypertrophy in 12-month old Hfe-deficient mice was consistent with decreased alpha myosin and increased beta myosin heavy chains, suggesting an alpha-to-beta conversion with age. This was accompanied by cardiac fibrosis and up-regulation of NFAT-c2, reflecting increased calcineurin/NFAT signaling in myocyte hypertrophy. Moreover, there was an age-dependent increase in the cardiac isoprostane levels in Hfe-deficient mice, indicating elevated oxidative stress. Also, rats fed high-iron diet demonstrated increased heart-to-body weight ratios, alpha myosin heavy chain and cardiac isoprostane levels, suggesting that iron overload promotes oxidative stress and cardiac hypertrophy. Our findings provide a molecular basis for the progression of age-dependent cardiac stress exacerbated by iron overload hemochromatosis.
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Affiliation(s)
- Abitha Sukumaran
- Department of Pharmaceutical Sciences, Northeastern University, Boston, MA, USA
| | - JuOae Chang
- Department of Pharmaceutical Sciences, Northeastern University, Boston, MA, USA
| | - Murui Han
- Department of Pharmaceutical Sciences, Northeastern University, Boston, MA, USA
| | - Shrutika Mintri
- Department of Pharmaceutical Sciences, Northeastern University, Boston, MA, USA
| | - Ban-An Khaw
- Department of Pharmaceutical Sciences, Northeastern University, Boston, MA, USA
| | - Jonghan Kim
- Department of Pharmaceutical Sciences, Northeastern University, Boston, MA, USA.
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Saputra D, Chang J, Lee BJ, Yoon JH, Kim J, Lee K. Short-term manganese inhalation decreases brain dopamine transporter levels without disrupting motor skills in rats. J Toxicol Sci 2017; 41:391-402. [PMID: 27193731 DOI: 10.2131/jts.41.391] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Manganese (Mn) is used in industrial metal alloys and can be released into the atmosphere during methylcyclopentadienyl manganese tricarbonyl combustion. Increased Mn deposition in the brain after long-term exposure to the metal by inhalation is associated with altered dopamine metabolism and neurobehavioral problems, including impaired motor skills. However, neurotoxic effects of short-term exposure to inhaled Mn are not completely characterized. The purpose of this study is to define the neurobehavioral and neurochemical effects of short-term inhalation exposure to Mn at a high concentration using rats. Male Sprague-Dawley rats were exposed to MnCl2 aerosol in a nose-only inhalation chamber for 3 weeks (1.2 µm, 39 mg/m(3)). Motor coordination was tested on the day after the last exposure using a rotarod device at a fixed speed of 10 rpm for 2 min. Also, dopamine transporter and dopamine receptor protein expression levels in the striatum region of the brain were determined by Western blot analysis. At a rotarod speed of 10 rpm, there were no significant differences in the time on the bar before the first fall or the number of falls during the two-minute test observed in the exposed rats, as compared with controls. The Mn-exposed group had significantly higher Mn levels in the lung, blood, olfactory bulb, prefrontal cortex, striatum, and cerebellum compared with the control group. A Mn concentration gradient was observed from the olfactory bulb to the striatum, supporting the idea that Mn is transported via the olfactory pathway. Our results demonstrated that inhalation exposure to 39 mg/m(3) Mn for 3 weeks induced mild lung injury and modulation of dopamine transporter expression in the brain, without altering motor activity.
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Affiliation(s)
- Devina Saputra
- Inhalation Toxicology Center, Korea Institute of Toxicology, Korea
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Menon AV, Chang J, Kim J. Mechanisms of divalent metal toxicity in affective disorders. Toxicology 2015; 339:58-72. [PMID: 26551072 DOI: 10.1016/j.tox.2015.11.001] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Revised: 10/19/2015] [Accepted: 11/03/2015] [Indexed: 01/01/2023]
Abstract
Metals are required for proper brain development and play an important role in a number of neurobiological functions. The divalent metal transporter 1 (DMT1) is a major metal transporter involved in the absorption and metabolism of several essential metals like iron and manganese. However, non-essential divalent metals are also transported through this transporter. Therefore, altered expression of DMT1 can modify the absorption of toxic metals and metal-induced toxicity. An accumulating body of evidence has suggested that increased metal stores in the brain are associated with elevated oxidative stress promoted by the ability of metals to catalyze redox reactions, resulting in abnormal neurobehavioral function and the progression of neurodegenerative diseases. Metal overload has also been implicated in impaired emotional behavior, although the underlying mechanisms are not well understood with limited information. The current review focuses on psychiatric dysfunction associated with imbalanced metabolism of metals that are transported by DMT1. The investigations with respect to the toxic effects of metal overload on behavior and their underlying mechanisms of toxicity could provide several new therapeutic targets to treat metal-associated affective disorders.
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Affiliation(s)
| | - JuOae Chang
- Department of Pharmaceutical Sciences, Northeastern University, Boston, MA 02115, USA
| | - Jonghan Kim
- Department of Pharmaceutical Sciences, Northeastern University, Boston, MA 02115, USA.
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