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Zhu K, Liu Q, Xie X, Jiang Q, Feng Y, Xiao P, Wu X, Zhu B, Song R. Interaction between manganese and SLC6A3 genetic polymorphisms in relation to dyslexia. Neurotoxicology 2022; 92:102-109. [DOI: 10.1016/j.neuro.2022.08.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 07/11/2022] [Accepted: 08/04/2022] [Indexed: 12/09/2022]
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Abu-Elfotuh K, Hamdan AME, Abbas AN, Alahmre ATS, Elewa MAF, Masoud RAE, Ali AA, Othman M, Kamal MM, Hassan FAM, Khalil MG, El-Sisi AM, Abdel Hady MMM, Abd-Elhaleim El Azazy MK, Awny MM, Wahid A. Evaluating the neuroprotective activities of vinpocetine, punicalagin, niacin and vitamin E against behavioural and motor disabilities of manganese-induced Parkinson's disease in Sprague Dawley rats. Biomed Pharmacother 2022; 153:113330. [PMID: 35780621 DOI: 10.1016/j.biopha.2022.113330] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Revised: 06/22/2022] [Accepted: 06/22/2022] [Indexed: 01/22/2023] Open
Abstract
The current study investigated the neuroprotective activity of some drugs and nutriceuticals with antioxidant and anti-inflammatory potential on the pathogenesis of Parkinson's disease (PD). Rats were categorized into seven groups: Rats received tween80 daily for 5 weeks as a control group, MnCl2 (10 mg/kg, i.p) either alone (group II) or in combination with vinpocetine (VIN) (20 mg/kg) (group III), punicalagin (PUN) (30 mg/kg) (group IV), niacin (85 mg/kg) (group V), vitamin E (Vit E) (100 mg/kg) (group VI) or their combination (group VII). Motor activities was examined using open-field and catalepsy. Striatal monamines, acetylcholinesterase, excitatory/inhibitory neurotransmitters, redox status, pro-oxidant content, brain inflammatory, apoptotic and antioxidant biomarkers levels were assessed. Besides, histopathological investigations of different brain regions were determined. Groups (IV -GVII) showed improved motor functions of PD rats. Applied drugs significantly increased the brain levels of monoamines with the strongest effect to PUN. Meanwhile, they significantly decreased levels of acetylcholinesterase with a strongest effect to PUN. Moreover, they exhibited significant neuronal protection and anti-inflammatory abilities through significant reduction of the brain levels of COX2, TNF-α and Il-1β with a strongest effect to the PUN. Interestingly; groups (IV - GVII) showed restored glutamate/GABA balance and exhibited a pronounced decrease in caspase-3 content and GSK-3β protein expression levels. In addition, they significantly increased Bcl2 mRNA expression levels with a strongest effect for PUN. All these findings were further confirmed by the histopathological examinations. As a conclusion, we propose VIN and PUN to mitigate the progression of PD via their antioxidant, anti-inflammatory, anti-apoptotic, neurotrophic and neurogenic activities.
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Affiliation(s)
- Karema Abu-Elfotuh
- Pharmacology and Toxicology Department (Girls), Faculty of Pharmacy, Al-Azhar University, Cairo, Egypt
| | | | | | | | - Mohammed A F Elewa
- Biochemistry Department, Faculty of Pharmacy, Kafrelsheikh University, Kafr El-Sheikh 33516, Egypt
| | - Rehab Ali Elsayed Masoud
- Forensic Medicine and Clinical Toxicology Department, Faculty of medicine for girls, Al-Azhar University, Cairo, Egypt
| | - Azza A Ali
- Pharmacology and Toxicology Department (Girls), Faculty of Pharmacy, Al-Azhar University, Cairo, Egypt
| | - Mohamed Othman
- Lecturer, Department of anatomy, Faculty of Medicine, King Salman International University, El-Tur Campus, Saini, Egypt
| | - Mona M Kamal
- Pharmacology and Toxicology Department (Girls), Faculty of Pharmacy, Al-Azhar University, Cairo, Egypt
| | - Fatma Alzahraa M Hassan
- Biochemistry and molecular biology Department, Faculty of Pharmacy, Al-Azhar, University, Cairo, Egypt
| | - Mona G Khalil
- Pharmacology and Toxicology Department, Modern University for Technology and Information, Cairo, Egypt
| | - Ahmed M El-Sisi
- Biochemistry and Molecular Biology Department (boys), Faculty of Pharmacy, Al-Azhar University, Cairo, Egypt; Biochemistry Department, Faculty of Pharmacy, Nahda University (NUB), Beni-Suef, Egypt
| | - Manal M M Abdel Hady
- Department of Pharmacology, Faculty of Pharmacy, Qantra University, Sinai, Egypt
| | | | - Magdy M Awny
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, October 6 University, Cairo, Egypt
| | - Ahmed Wahid
- Department of Pharmaceutical Biochemistry, Faculty of Pharmacy, Alexandria University, Alexandria, Egypt
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Xu Y, Peng T, Xiang Y, Liao G, Zou F, Meng X. Neurotoxicity and gene expression alterations in zebrafish larvae in response to manganese exposure. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 825:153778. [PMID: 35150691 DOI: 10.1016/j.scitotenv.2022.153778] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2021] [Revised: 02/03/2022] [Accepted: 02/06/2022] [Indexed: 06/14/2023]
Abstract
Manganese (Mn) is an essential trace element, but excessive exposure can damage mental, cognitive, and motor functions. Although many studies have reported the toxicity of Mn, the underlying mechanism remains unclear. Here, wild-type and/or Tg(NBT:DsRed) zebrafish embryos/larvae were exposed to different dosages of Mn to determine the effects on mortality, malformation, and hatching rates. A video tracking system was used to analyze the locomotor activities of zebrafish larvae. The terminal deoxynucleotidyl transferase dUTP nick end labeling assay and acridine orange staining were performed to monitor cell apoptosis, while dopamine transporter and tyrosine hydroxylase (TH) expression were detected by immunohistochemical staining. Meanwhile, transcriptome sequencing of the head tissues of zebrafish larvae was performed to search for molecular targets of Mn neurotoxicity. The results showed that Mn exposure increased the mortality and malformation rates of zebrafish larvae, and significantly reduced swim distance and velocity. In addition, the proportion of apoptotic dopaminergic neurons increased, while TH expression significantly decreased. The results of transcriptome sequencing showed that a large number of differentially expressed genes associated with apoptosis and DNA damage repair were upregulated, consistent with the above results. Meanwhile, Western blot analysis showed that higher exposure level of Mn could induce activation of MAPK pathway. These data demonstrate that Mn exposure can damage dopaminergic neurons and cause apoptosis, which has detrimental effects on the motor abilities of zebrafish larvae.
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Affiliation(s)
- Yongjie Xu
- Department of Occupational Health and Occupational Medicine, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, Guangdong, China
| | - Tao Peng
- Department of Occupational Health and Occupational Medicine, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, Guangdong, China
| | - Yang Xiang
- Department of Occupational Health and Occupational Medicine, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, Guangdong, China
| | - Gengze Liao
- Department of Occupational Health and Occupational Medicine, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, Guangdong, China
| | - Fei Zou
- Department of Occupational Health and Occupational Medicine, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, Guangdong, China
| | - Xiaojing Meng
- Department of Occupational Health and Occupational Medicine, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, Guangdong, China.
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Mechanism of Manganese Dysregulation of Dopamine Neuronal Activity. J Neurosci 2020; 40:5871-5891. [PMID: 32576620 DOI: 10.1523/jneurosci.2830-19.2020] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 05/27/2020] [Accepted: 05/29/2020] [Indexed: 01/01/2023] Open
Abstract
Manganese exposure produces Parkinson's-like neurologic symptoms, suggesting a selective dysregulation of dopamine transmission. It is unknown, however, how manganese accumulates in dopaminergic brain regions or how it regulates the activity of dopamine neurons. Our in vivo studies in male C57BLJ mice suggest that manganese accumulates in dopamine neurons of the VTA and substantia nigra via nifedipine-sensitive Ca2+ channels. Manganese produces a Ca2+ channel-mediated current, which increases neurotransmitter release and rhythmic firing activity of dopamine neurons. These increases are prevented by blockade of Ca2+ channels and depend on downstream recruitment of Ca2+-activated potassium channels to the plasma membrane. These findings demonstrate the mechanism of manganese-induced dysfunction of dopamine neurons, and reveal a potential therapeutic target to attenuate manganese-induced impairment of dopamine transmission.SIGNIFICANCE STATEMENT Manganese is a trace element critical to many physiological processes. Overexposure to manganese is an environmental risk factor for neurologic disorders, such as a Parkinson's disease-like syndrome known as manganism. We found that manganese concentration-dependently increased the excitability of dopamine neurons, decreased the amplitude of action potentials, and narrowed action potential width. Blockade of Ca2+ channels prevented these effects as well as manganese accumulation in the mouse midbrain in vivo Our data provide a potential mechanism for manganese regulation of dopaminergic neurons.
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El Fari R, Abbaoui A, Bourziq A, Zroudi M, Draoui A, El Khiat A, Belkouch M, Elgot A, Gamrani H. Neuroprotective effects of docosahexaenoic acid against sub-acute manganese intoxication induced dopaminergic and motor disorders in mice. J Chem Neuroanat 2019; 102:101686. [DOI: 10.1016/j.jchemneu.2019.101686] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Revised: 08/22/2019] [Accepted: 09/24/2019] [Indexed: 01/07/2023]
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Markowski VP, Miller-Rhodes P, Cheung R, Goeke C, Pecoraro V, Cohen G, Small DJ. Motor deficits, impaired response inhibition, and blunted response to methylphenidate following neonatal exposure to decabromodiphenyl ether. Neurotoxicol Teratol 2017; 63:51-59. [PMID: 28764964 DOI: 10.1016/j.ntt.2017.07.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Revised: 07/18/2017] [Accepted: 07/27/2017] [Indexed: 12/30/2022]
Abstract
Decabromodiphenyl ether (decaBDE) is an applied brominated flame retardant that is widely-used in electronic equipment. After decades of use, decaBDE and other members of its polybrominated diphenyl ether class have become globally-distributed environmental contaminants that can be measured in the atmosphere, water bodies, wildlife, food staples and human breastmilk. Although it has been banned in Europe and voluntarily withdrawn from the U.S. market, it is still used in Asian countries. Evidence from epidemiological and animal studies indicate that decaBDE exposure targets brain development and produces behavioral impairments. The current study examined an array of motor and learning behaviors in a C57BL6/J mouse model to determine the breadth of the developmental neurotoxicity produced by decaBDE. Mouse pups were given a single daily oral dose of 0 or 20mg/kg decaBDE from postnatal day 1 to 21 and were tested in adulthood. Exposed male mice had impaired forelimb grip strength, altered motor output in a circadian wheel-running procedure, increased response errors during an operant differential reinforcement of low rates (DRL) procedure and a blunted response to an acute methylphenidate challenge administered before DRL testing. With the exception of altered wheel-running output, exposed females were not affected. Neither sex had altered somatic growth, motor coordination impairments on the Rotarod, gross learning deficits during operant lever-press acquisition, or impaired food motivation. The overall pattern of effects suggests that males are more sensitive to developmental decaBDE exposure, especially when performing behaviors that require effortful motor output or when learning tasks that require sufficient response inhibition for their successful completion.
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Affiliation(s)
- Vincent P Markowski
- Department of Psychology, State University of New York at Geneseo, Geneseo, NY 14454, United States.
| | - Patrick Miller-Rhodes
- Department of Psychology, State University of New York at Geneseo, Geneseo, NY 14454, United States
| | - Randy Cheung
- Department of Psychology, State University of New York at Geneseo, Geneseo, NY 14454, United States
| | - Calla Goeke
- Department of Psychology, State University of New York at Geneseo, Geneseo, NY 14454, United States
| | - Vincent Pecoraro
- Department of Psychology, State University of New York at Geneseo, Geneseo, NY 14454, United States
| | - Gideon Cohen
- Department of Psychology, State University of New York at Geneseo, Geneseo, NY 14454, United States
| | - Deena J Small
- Department of Biochemistry, University of New England, Biddeford, ME 04005, United States
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Fleming SM, Santiago NA, Mullin EJ, Pamphile S, Karkare S, Lemkuhl A, Ekhator OR, Linn SC, Holden JG, Aga DS, Roth JA, Liou B, Sun Y, Shull GE, Schultheis PJ. The effect of manganese exposure in Atp13a2-deficient mice. Neurotoxicology 2017; 64:256-266. [PMID: 28595912 PMCID: PMC10178982 DOI: 10.1016/j.neuro.2017.06.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Revised: 05/25/2017] [Accepted: 06/03/2017] [Indexed: 12/30/2022]
Abstract
Loss of function mutations in the P5-ATPase ATP13A2 are associated with Kufor-Rakeb Syndrome and Neuronal Ceroid Lipofuscinosis. While the function of ATP13A2 is unclear, in vitro studies suggest it is a lysosomal protein that interacts with the metals manganese (Mn) and zinc and the presynaptic protein alpha-synuclein. Loss of ATP13A2 function in mice causes sensorimotor deficits, enhanced autofluorescent storage material, and accumulation of alpha-synuclein. The present study sought to determine the effect of Mn administration on these same outcomes in ATP13A2-deficient mice. Wildtype and ATP13A2-deficient mice received saline or Mn at 5-9 or 12-19 months for 45days. Sensorimotor function was assessed starting at day 30. Autofluorescence was quantified in multiple brain regions and alpha-synuclein protein levels were determined in the ventral midbrain. Brain Mn, iron, zinc, and copper concentrations were measured in 5-9 month old mice. The results show Mn enhanced sensorimotor function, increased autofluorescence in the substantia nigra, and increased insoluble alpha-synuclein in the ventral midbrain in older ATP13A2-deficient mice. In addition, the Mn regimen used increased Mn concentration in the brain and levels were higher in Mn-treated mutants than controls. These results indicate loss of ATP13A2 function leads to increased sensitivity to Mn in vivo.
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Affiliation(s)
- Sheila M Fleming
- Department of Pharmaceutical Sciences, Northeast Ohio Medical University, Rootstown, OH, United States.
| | - Nicholas A Santiago
- Department of Pharmaceutical Sciences, Northeast Ohio Medical University, Rootstown, OH, United States
| | | | - Shanta Pamphile
- Department of Neurology, University of Cincinnati, Cincinnati, OH, United States
| | - Swagata Karkare
- Department of Neurology, University of Cincinnati, Cincinnati, OH, United States
| | - Andrew Lemkuhl
- Department of Neurology, University of Cincinnati, Cincinnati, OH, United States
| | - Osunde R Ekhator
- Department of Neurology, University of Cincinnati, Cincinnati, OH, United States
| | - Stephen C Linn
- Department of Biological Sciences, Northern Kentucky University, Highland Heights, KY, United States
| | - John G Holden
- Department of Neurology, University of Cincinnati, Cincinnati, OH, United States
| | - Diana S Aga
- Department of Chemistry, SUNY Buffalo, Buffalo, NY, United States
| | - Jerome A Roth
- Department of Pharmacology and Toxicology, SUNY Buffalo, Buffalo, NY, United States
| | - Benjamin Liou
- Division of Human Genetics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States
| | - Ying Sun
- Division of Human Genetics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States
| | - Gary E Shull
- Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati, Cincinnati, OH, United States
| | - Patrick J Schultheis
- Department of Biological Sciences, Northern Kentucky University, Highland Heights, KY, United States
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Essawy SS, Tawfik MK, Korayem HE. Effects of adenosine receptor antagonists in MPTP mouse model of Parkinson's disease: mitochondrial DNA integrity. Arch Med Sci 2017; 13:659-669. [PMID: 28507584 PMCID: PMC5420638 DOI: 10.5114/aoms.2017.67284] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/19/2015] [Accepted: 05/19/2015] [Indexed: 12/17/2022] Open
Abstract
INTRODUCTION In Parkinson's disease (PD), compelling data indicate a functional link between adenosine/dopamine receptors and the progression of the neurodegenerative process. The present study was carried out to evaluate the effect of the non-selective adenosine receptor (ADR) antagonist caffeine, as well as the selective antagonists 8-cyclopentyl-1,3-dipropylxanthine (DPCPX), an ADRsA1 antagonist, and ((E)-1,3-diethyl-8-(3,4-dimethoxystyryl)-7-methyl-3,7-dihydro-1H-purine-2,6-dione) (KW-6002), an ADRsA2A antagonist, on the prevention of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced Parkinsonism in mice. MATERIAL AND METHODS Mice were allocated to five groups: group I - control group; group II: MPTP group, received four injections of MPTP (20 mg/kg, i.p.) at 2 h intervals; groups III, IV, V: received MPTP and i.p. caffeine (20 mg/kg/day) or DPCPX (5 mg/kg/day) or KW-6002 (10 mg/kg/day) starting one week before MPTP injection and continuing for 2 weeks. RESULTS Therapy with caffeine or KW-6002 not only led to the reversibility of movement dysfunction and increased the concentrations of dopamine and ATP levels (p < 0.05), but also, ameliorates the dopaminergic neuron loss and restored the mtDNA and nDNA integrity (p < 0.05). Furthermore, in passive avoidance test, caffeine and DPCPX significantly (p < 0.05) reversed the MPTP-induced memory deficits, whereas the specific ADRsA2A antagonist did not. CONCLUSIONS The current results provide evidence that blockade of both ADRsA1 and ADRsA2A has therapeutic implications in alleviating MPTP-induced motor and cognitive dysfunction and might be a promising candidate for treatment of PD.
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Affiliation(s)
- Soha S. Essawy
- Department of Pharmacology, Faculty of Medicine, Suez Canal University, Ismailia, Egypt
| | - Mona Kamal Tawfik
- Department of Pharmacology, Faculty of Medicine, Suez Canal University, Ismailia, Egypt
| | - Horya Erfan Korayem
- Department of Histology, Faculty of Medicine, Suez Canal University, Ismailia, Egypt
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Manganese-Induced Parkinsonism and Parkinson's Disease: Shared and Distinguishable Features. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2015; 12:7519-40. [PMID: 26154659 PMCID: PMC4515672 DOI: 10.3390/ijerph120707519] [Citation(s) in RCA: 220] [Impact Index Per Article: 24.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Revised: 12/12/2014] [Accepted: 01/06/2015] [Indexed: 11/30/2022]
Abstract
Manganese (Mn) is an essential trace element necessary for physiological processes that support development, growth and neuronal function. Secondary to elevated exposure or decreased excretion, Mn accumulates in the basal ganglia region of the brain and may cause a parkinsonian-like syndrome, referred to as manganism. The present review discusses the advances made in understanding the essentiality and neurotoxicity of Mn. We review occupational Mn-induced parkinsonism and the dynamic modes of Mn transport in biological systems, as well as the detection and pharmacokinetic modeling of Mn trafficking. In addition, we review some of the shared similarities, pathologic and clinical distinctions between Mn-induced parkinsonism and Parkinson’s disease. Where possible, we review the influence of Mn toxicity on dopamine, gamma aminobutyric acid (GABA), and glutamate neurotransmitter levels and function. We conclude with a survey of the preventive and treatment strategies for manganism and idiopathic Parkinson’s disease (PD).
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Chen P, Chakraborty S, Peres TV, Bowman AB, Aschner M. Manganese-induced Neurotoxicity: From C. elegans to Humans. Toxicol Res (Camb) 2014; 4:191-202. [PMID: 25893090 DOI: 10.1039/c4tx00127c] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Manganese (Mn) is one of the most abundant metals on the earth. It is required for normal cellular activities, but overexposure leads to toxicity. Neurons are more susceptible to Mn-induced toxicity than other cells, and accumulation of Mn in the brain results in Manganism that presents with Parkinson's disease (PD)-like symptoms. In the last decade, a number of Mn transporters have been identified, which improves our understanding of Mn transport in and out of cells. However, the mechanism of Mn-induced neurotoxicity is only partially uncovered, with further research needed to explore the whole picture of Mn-induced toxicity. In this review, we will address recent progress in Mn-induced neurotoxicity from C. elegans to humans, and explore future directions that will help understand the mechanisms of its neurotoxicity.
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Affiliation(s)
- Pan Chen
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Sudipta Chakraborty
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Tanara V Peres
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY, USA ; Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil
| | - Aaron B Bowman
- Department of Neurology, Vanderbilt University Medical Center, Nashville TN, USA
| | - Michael Aschner
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY, USA
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O'Neal SL, Lee JW, Zheng W, Cannon JR. Subacute manganese exposure in rats is a neurochemical model of early manganese toxicity. Neurotoxicology 2014; 44:303-13. [PMID: 25117542 DOI: 10.1016/j.neuro.2014.08.001] [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: 03/21/2014] [Revised: 06/30/2014] [Accepted: 08/01/2014] [Indexed: 12/21/2022]
Abstract
Manganese (Mn) is an essential trace element, but excess exposure leads to accumulation in biological tissues, including the brain. Chronically high Mn levels in the brain are neurotoxic and can result in a progressive, irreversible neurological disorder known as manganism. Manganism has signs and symptoms similar to, but distinguishable from idiopathic Parkinson's disease, which include both psychological and motor disturbances. Evidence suggests that Mn exposure impacts neurotransmitter levels in the brain. However, it remains unclear if subacute, low-level Mn exposure resulted in alterations in neurotransmitter systems with concomitant behavioral deficits. The current study used high performance liquid chromatography to quantify neurotransmitter levels in rat striatum (STR), substantia nigra (SN), and hippocampus (HP). Subacute Mn exposure via i.p. injection of 15mg Mn/kg as MnCl2 caused significantly increased dopamine (DA) levels in the STR. The enhancement was accompanied by significantly elevated levels of the DA metabolites, 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA), in the STR. In addition, levels of HVA were significantly increased in the SN and HP. These data indicate that subacute, low-level Mn exposure disrupts multiple neurotransmitter systems in the rat brain which may be responsible, in part, for observed locomotor deficits.
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Affiliation(s)
- Stefanie L O'Neal
- School of Health Sciences, Purdue University, West Lafayette, IN 47907, USA
| | - Jang-Won Lee
- School of Health Sciences, Purdue University, West Lafayette, IN 47907, USA
| | - Wei Zheng
- School of Health Sciences, Purdue University, West Lafayette, IN 47907, USA.
| | - Jason R Cannon
- School of Health Sciences, Purdue University, West Lafayette, IN 47907, USA.
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