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Dong T, Li H. Neurological risks arising from the bioaccumulation of heavy metal contaminants: A focus on mercury. ENVIRONMENTAL TOXICOLOGY 2024; 39:2692-2705. [PMID: 38240341 DOI: 10.1002/tox.24119] [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: 09/27/2023] [Revised: 12/18/2023] [Accepted: 12/25/2023] [Indexed: 04/17/2024]
Abstract
This study investigated the concentrations of heavy metals in the water sources of the upstream region of the Huangpu River, the Yangtze River Estuary, and various areas in Shanghai, as well as the heavy metal concentrations in the blood of Shanghai residents. It aimed to analyze the heavy metal elements absorbed by the human body and the resulting pathological effects. The results revealed that surface water primarily contains five heavy metals: copper (Cu), lead (Pb), zinc (Zn), arsenic (As), and mercury (Hg), while water sediments primarily contain seven heavy metals: Cu, cadmium (Cd), Pb, chromium (Cr), Zn, As, and Hg. The main heavy metals present in the human body are Pb, Hg, As, and Cd. By reviewing previous articles, it was found that heavy metal concentrations in human blood are higher than those in surface water, suggesting uncertainties in the heavy metal content of surface water and its tendency to settle at the bottom. Furthermore, a comparison of heavy metal content in sediments revealed that Hg is the most readily absorbed heavy metal by the human body and is also a toxic environmental pollutant. Within the cell, Hg is highly toxic to mitochondria and may cause oxidative stress and neurodegenerative disease. This study concludes that water sediments serve as the major source of pollution in the human body and pose significant health risks, thereby necessitating the implementation of effective preventive measures.
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Affiliation(s)
- Tianyu Dong
- Municipal Environmental Engineering College, Qingdao University of Technology, Qingdao, China
- Shanghai WLSA Academy, Shanghai, China
| | - Hanxuan Li
- Municipal Environmental Engineering College, Qingdao University of Technology, Qingdao, China
- Shanghai WLSA Academy, Shanghai, China
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Lee CK, Wang FT, Huang CH, Chan WH. Prevention of methylmercury-triggered ROS-mediated impairment of embryo development by co-culture with adult adipose-derived mesenchymal stem cells. Toxicol Res (Camb) 2024; 13:tfad122. [PMID: 38162594 PMCID: PMC10753290 DOI: 10.1093/toxres/tfad122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Revised: 10/19/2023] [Accepted: 12/08/2023] [Indexed: 01/03/2024] Open
Abstract
Methylmercury (MeHg) is a potent toxin that exerts deleterious effects on human health via environmental contamination. Significant effects of MeHg on neuronal development in embryogenesis have been reported. Recently, our group demonstrated that MeHg exerts toxic effects on pre- and post-implantation embryonic development processes from zygote to blastocyst stage. Our results showed that MeHg impairs embryo development by induction of apoptosis through reactive oxygen species (ROS) generation that triggers caspase-3 cleavage and activation, which, in turn, stimulates p21-activated kinase 2 (PAK2) activity. Importantly, ROS were identified as a key upstream regulator of apoptotic events in MeHg-treated blastocysts. Data from the current study further confirmed that MeHg exerts hazardous effects on cell proliferation, apoptosis, implantation, and pre- and post-implantation embryo development. Notably, MeHg-induced injury was markedly prevented by co-culture with adipose-derived mesenchymal stem cells (ADMSCs) in vitro. Furthermore, ADMSC injection significantly reduced MeHg-mediated deleterious effects on embryo, placenta, and fetal development in vivo. Further investigation of the regulatory mechanisms by which co-cultured ADMSCs could prevent MeHg-induced impairment of embryo development revealed that ADMSCs effectively reduced ROS generation and its subsequent downstream apoptotic events, including loss of mitochondrial membrane potential and activation of caspase-3 and PAK2. The collective findings indicate that co-culture with mesenchymal stem cells (MSCs) or utilization of MSC-derived cell-conditioned medium offers an effective potential therapeutic strategy to prevent impairment of embryo development by MeHg.
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Affiliation(s)
- Cheng-Kai Lee
- Department of Obstetrics and Gynecology, Taoyuan General Hospital, Ministry of Health & Welfare, Zhongshan Road, Taoyuan District, Taoyuan City 33004, Taiwan
| | - Fu-Ting Wang
- Rehabilitation and Technical Aid Center, Taipei Veterans General Hospital, Section 2, Shipai Road, Beitou District, Taipei City 11217, Taiwan
| | - Chien-Hsun Huang
- Hungchi Gene IVF Center, Daxing West Road, Taoyuan District, Taoyuan City 330012, Taiwan
| | - Wen-Hsiung Chan
- Department of Bioscience Technology and Center for Nanotechnology, Chung Yuan Christian University, Zhongbei Road, Zhongli District, Taoyuan City 32023, Taiwan
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Sharma S, Mehan S, Khan Z, Gupta GD, Narula AS. Icariin prevents methylmercury-induced experimental neurotoxicity: Evidence from cerebrospinal fluid, blood plasma, brain samples, and in-silico investigations. Heliyon 2024; 10:e24050. [PMID: 38226245 PMCID: PMC10788811 DOI: 10.1016/j.heliyon.2024.e24050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Revised: 11/29/2023] [Accepted: 01/02/2024] [Indexed: 01/17/2024] Open
Abstract
Amyotrophic Lateral Sclerosis (ALS) is a fatal neurodegenerative disease that causes significant neurodegeneration. Methylmercury (MeHg+) is a neurotoxin that induces axonal neurodegeneration and motor nerve degeneration by destroying oligodendrocytes, degenerating white matter, inducing apoptosis, excitotoxicity, and reducing myelin basic protein (MBP). This study examines the inhibition of SIRT-1 (silence information regulator 1), Nrf-2 (nuclear factor E2-related factor 2), HO-1 (heme oxygenase 1), and TDP-43 (TAR-DNA-binding protein 43) accumulation in the context of ALS, as well as the modulation of these proteins by icariin (15 and 30 mg/kg, orally), a glycoside flavonoid with neuroprotective properties. Neuroprotective icariin activates SIRT-1, Nrf-2, and HO-1, mitigating inflammation and neuronal injury in neurodegenerative disorders. In-vivo and in-silico testing of experimental ALS models confirmed icariin efficacy in modulating these cellular targets. The addition of sirtinol 10 mg/kg, an inhibitor of SIRT-1, helps determine the effectiveness of icariin. In this study, we also examined neurobehavioral, neurochemical, histopathological, and LFB (Luxol fast blue) markers in various biological samples, including Cerebrospinal fluid (CSF), blood plasma, and brain homogenates (Cerebral Cortex, Hippocampus, Striatum, mid-brain, and Cerebellum). These results demonstrate that the administration of icariin ameliorates experimental ALS and that the mechanism underlying these benefits is likely related to regulating the SIRT-1, Nrf-2, and HO-1 signaling pathways.
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Affiliation(s)
- Sarthak Sharma
- Division of Neuroscience, Department of Pharmacology, ISF College of Pharmacy (Affiliated to IK Gujral Punjab Technical University, Jalandhar, Punjab, 144603, India), Moga, Punjab, India
| | - Sidharth Mehan
- Division of Neuroscience, Department of Pharmacology, ISF College of Pharmacy (Affiliated to IK Gujral Punjab Technical University, Jalandhar, Punjab, 144603, India), Moga, Punjab, India
| | - Zuber Khan
- Division of Neuroscience, Department of Pharmacology, ISF College of Pharmacy (Affiliated to IK Gujral Punjab Technical University, Jalandhar, Punjab, 144603, India), Moga, Punjab, India
| | - Ghanshyam Das Gupta
- Department of Pharmaceutics, ISF College of Pharmacy (Affiliated to IK Gujral Punjab Technical University, Jalandhar, Punjab, 144603, India), Moga, Punjab, India
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Kumar S, Mehan S, Khan Z, Das Gupta G, Narula AS. Guggulsterone Selectively Modulates STAT-3, mTOR, and PPAR-Gamma Signaling in a Methylmercury-Exposed Experimental Neurotoxicity: Evidence from CSF, Blood Plasma, and Brain Samples. Mol Neurobiol 2024:10.1007/s12035-023-03902-x. [PMID: 38170440 DOI: 10.1007/s12035-023-03902-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Accepted: 12/14/2023] [Indexed: 01/05/2024]
Abstract
Amyotrophic lateral sclerosis (ALS) is a paralytic disease that damages the brain and spinal cord motor neurons. Several clinical and preclinical studies have found that methylmercury (MeHg+) causes ALS. In ALS, MeHg+-induced neurotoxicity manifests as oligodendrocyte destruction; myelin basic protein (MBP) deficiency leads to axonal death. ALS development has been connected to an increase in signal transducer and activator of transcription-3 (STAT-3), a mammalian target of rapamycin (mTOR), and a decrease in peroxisome proliferator-activated receptor (PPAR)-gamma. Guggulsterone (GST), a plant-derived chemical produced from Commiphorawhighitii resin, has been found to protect against ALS by modulating these signaling pathways. Vitamin D3 (VitD3) deficiency has been related to oligodendrocyte precursor cells (OPC) damage, demyelination, and white matter deterioration, which results in motor neuron death. As a result, the primary goal of this work was to investigate the therapeutic potential of GST by altering STAT-3, mTOR, and PPAR-gamma levels in a MeHg+-exposed experimental model of ALS in adult rats. The GST30 and 60 mg/kg oral treatments significantly improved the behavioral, motor, and cognitive dysfunctions and increased remyelination, as proven by the Luxol Fast Blue stain (LFB), and reduced neuroinflammation as measured by histological examinations. Furthermore, the co-administration of VitD3 exhibits moderate efficacy when administered in combination with GST60. Our results show that GST protects neurons by decreasing STAT-3 and mTOR levels while increasing PPAR-gamma protein levels in ALS rats.
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Affiliation(s)
- Sumit Kumar
- Division of Neuroscience, Department of Pharmacology, ISF College of Pharmacy (An Autonomous College), NAAC Accredited "A" Grade College, GT Road, Ghal-Kalan, Moga, 142 001, Punjab, India
- IK Gujral Punjab Technical University, Jalandhar, Punjab, 144603, India
| | - Sidharth Mehan
- Division of Neuroscience, Department of Pharmacology, ISF College of Pharmacy (An Autonomous College), NAAC Accredited "A" Grade College, GT Road, Ghal-Kalan, Moga, 142 001, Punjab, India.
- IK Gujral Punjab Technical University, Jalandhar, Punjab, 144603, India.
| | - Zuber Khan
- Division of Neuroscience, Department of Pharmacology, ISF College of Pharmacy (An Autonomous College), NAAC Accredited "A" Grade College, GT Road, Ghal-Kalan, Moga, 142 001, Punjab, India
- IK Gujral Punjab Technical University, Jalandhar, Punjab, 144603, India
| | - Ghanshyam Das Gupta
- IK Gujral Punjab Technical University, Jalandhar, Punjab, 144603, India
- Department of Pharmaceutics, ISF College of Pharmacy, Moga, Punjab, India
| | - Acharan S Narula
- Narula Research, LLC, 107 Boulder Bluff, Chapel Hill, NC, 27516, USA
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Lee CK, Wang FT, Huang CH, Chan WH. Role of activated p21-activated kinase 2 in methylmercury-induced embryotoxic effects on mouse blastocysts. Toxicol Res (Camb) 2023; 12:433-445. [PMID: 37397923 PMCID: PMC10311136 DOI: 10.1093/toxres/tfad030] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Revised: 03/09/2023] [Accepted: 04/06/2023] [Indexed: 07/04/2023] Open
Abstract
Methylmercury (MeHg), a biotransformation product derived from mercury or inorganic mercury compounds in waterways, is a potent toxin that exerts hazardous effects on human health via environmental contamination. Previous studies have reported MeHg-induced impairment of nerve development in embryogenesis and placental development. However, the potential deleterious effects and regulatory mechanisms of action of MeHg on pre- and post-implantation embryo development are yet to be established. Experiments from the current study clearly demonstrate that MeHg exerts toxic effects on early embryonic development processes, including the zygote to blastocyst stage. Induction of apoptosis and decrease in embryo cell number were clearly detected in MeHg-treated blastocysts. Additionally, intracellular reactive oxygen species (ROS) generation and activation of caspase-3 and p21-activated protein kinase 2 (PAK2) were observed in MeHg-treated blastocysts. Importantly, prevention of ROS generation by pre-treatment with Trolox, a potent antioxidant, significantly attenuated MeHg-triggered caspase-3 and PAK2 activation as well as apoptosis. Notably, the downregulation of PAK2 via transfection of specifically targeted siRNA (siPAK2) led to marked attenuation of PAK2 activity and apoptosis and the deleterious effects of MeHg on embryonic development in blastocysts. Our findings strongly suggest that ROS serve as an important upstream regulator to trigger the activation of caspase-3, which further cleaves and activates PAK2 in MeHg-treated blastocysts. Activated PAK2 promotes apoptotic processes that, in turn, cause sequent impairment of embryonic and fetal development.
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Affiliation(s)
- Cheng-Kai Lee
- Department of Obstetrics and Gynecology, Taoyuan General Hospital, Ministry of Health & Welfare, Taoyuan City 33004, Taiwan
| | - Fu-Ting Wang
- Rehabilitation and Technical Aid Center, Taipei Veterans General Hospital, Taipei City 11217, Taiwan
| | - Chien-Hsun Huang
- Hungchi Gene IVF Center, Taoyuan District, Taoyuan City 330012, Taiwan
| | - Wen-Hsiung Chan
- Corresponding author: Department of Bioscience Technology and Center for Nanotechnology, Chung Yuan Christian University, Chung Li District, Taoyuan City 32023, Taiwan. Fax: +886-3-2653599; E-mail:
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Chen N, Yan J, Hu Y, Hao L, Liu H, Yang H. Study of the mechanism underlying the role of PINK1/Parkin in the formic acid-induced autophagy of PC12 cells. Basic Clin Pharmacol Toxicol 2023; 132:329-342. [PMID: 36598398 DOI: 10.1111/bcpt.13833] [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: 04/23/2022] [Revised: 12/27/2022] [Accepted: 01/02/2023] [Indexed: 01/05/2023]
Abstract
This study aimed to explore PINK1/Parkin's role in methanol metabolite formic acid-induced autophagy in PC12 cells and provide a theoretical basis for elucidating methanol-induced neurotoxicity. After treatment with different formic acid concentrations, we observed the morphology and mitochondria of PC12 cells. We used an ultra-micro enzyme kit to detect the mitochondrial Na+ -K+ -ATPase and Ca2+ -Mg2+ -ATPase activities; a JC-1 kit to detect changes in the mitochondrial membrane potential (MMP); MDC staining to detect the autophagy levels; and western blotting to measure the expression levels of the mitochondrial marker protein COX IV and the autophagy-related proteins Beclin1, P62 and LC3II/LC3I, and the mitochondrial and cytoplasmic levels of PINK1, Parkin and P-Parkin. Compared with the control group, the mitochondrial diameters, the mitochondrial Na+ -K+ -ATP and Ca2+ -Mg2+ -ATPase activities, the MMP, and the COX IV expression levels decreased significantly (P < 0.05). The fluorescence signal intensity (indicating autophagy); relative Beclin1 and LC3II/LC3I protein expression levels; and relative mitochondrial PINK1, Parkin and P-Parkin levels increased significantly, and the relative P62 protein expression levels and relative cytoplasmic PINK1, Parkin and P-Parkin levels decreased significantly (P < 0.05) compared with the control group. Thus, formic acid alters mitochondrial morphology, causes mitochondrial dysfunction, affects the PINK/Parkin pathway and, thus, activates the process of mitochondrial autophagy.
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Affiliation(s)
- Nan Chen
- Department of Occupational and Environmental Health, School of Public Health and Management, Ningxia Medical University, Yinchuan, Ningxia, People's Republic of China.,Ningxia Key Laboratory of Environmental Factors and Chronic Disease Control, Yinchuan, Ningxia, People's Republic of China
| | - Jiao Yan
- Xi'an Chang'an District Center for Disease Control and Prevention, Xi'an, Shanxi, People's Republic of China
| | - Yundi Hu
- Department of Occupational and Environmental Health, School of Public Health and Management, Ningxia Medical University, Yinchuan, Ningxia, People's Republic of China.,Ningxia Key Laboratory of Environmental Factors and Chronic Disease Control, Yinchuan, Ningxia, People's Republic of China
| | - Lele Hao
- Department of Occupational and Environmental Health, School of Public Health and Management, Ningxia Medical University, Yinchuan, Ningxia, People's Republic of China.,Ningxia Key Laboratory of Environmental Factors and Chronic Disease Control, Yinchuan, Ningxia, People's Republic of China
| | - Herong Liu
- Department of Occupational and Environmental Health, School of Public Health and Management, Ningxia Medical University, Yinchuan, Ningxia, People's Republic of China.,Ningxia Key Laboratory of Environmental Factors and Chronic Disease Control, Yinchuan, Ningxia, People's Republic of China
| | - Huifang Yang
- Department of Occupational and Environmental Health, School of Public Health and Management, Ningxia Medical University, Yinchuan, Ningxia, People's Republic of China.,Ningxia Key Laboratory of Environmental Factors and Chronic Disease Control, Yinchuan, Ningxia, People's Republic of China
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Song H, Huo M, Zhou M, Chang H, Li J, Zhang Q, Fang Y, Wang H, Zhang D. Carbon Nanomaterials-Based Electrochemical Sensors for Heavy Metal Detection. Crit Rev Anal Chem 2022:1-20. [PMID: 36463557 DOI: 10.1080/10408347.2022.2151832] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/07/2022]
Abstract
Heavy metals are commonly found in a wide range of environmental settings metals, but the potential toxicity associated with heavy metal exposure represents a major threat to global public health. It is thus vital that approaches to efficiently, reliably, and effectively detecting heavy metals in a range of sample types be established. Carbon nanomaterials offer many advantageous properties that make them well-suited to the design of sensitive, selective, easy-to-operate electrochemical biosensors ideal for detecting heavy metal ions. The present review offers an overview of recent progress in the development of carbon nanomaterial-based electrochemical sensors used to detect heavy metals. In addition to providing a detailed discussion of certain carbon nanomaterials such as carbon nanotubes, graphene, carbon fibers, carbon quantum dots, carbon nanospheres, mesoporous carbon, and Graphdiyne, we survey the challenges and future directions for this field. Overall, the studies discussed herein suggest that the further development of carbon nanomaterial-modified electrochemical sensors will support the integration of increasingly advanced sensor platforms to aid in detecting heavy metals in foods, environmental samples, and other settings, thereby benefitting human health and society as a whole.
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Affiliation(s)
- Huijun Song
- Research Center of Experimental Acupuncture Science, College of Acumox and Tuina, Tianjin University of Traditional Chinese Medicine, Tianjin, PR China
| | - Mingzhu Huo
- Research Center of Experimental Acupuncture Science, College of Acumox and Tuina, Tianjin University of Traditional Chinese Medicine, Tianjin, PR China
| | - Mengmeng Zhou
- Research Center of Experimental Acupuncture Science, College of Acumox and Tuina, Tianjin University of Traditional Chinese Medicine, Tianjin, PR China
| | - Hongen Chang
- Research Center of Experimental Acupuncture Science, College of Acumox and Tuina, Tianjin University of Traditional Chinese Medicine, Tianjin, PR China
| | - Jingrong Li
- College of Pharmaceutical Engineering of Traditional Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin, PR China
- State Key Laboratory of Component-based Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin, PR China
| | - Qingxiang Zhang
- Research Center of Experimental Acupuncture Science, College of Acumox and Tuina, Tianjin University of Traditional Chinese Medicine, Tianjin, PR China
| | - Yuxin Fang
- Research Center of Experimental Acupuncture Science, College of Acumox and Tuina, Tianjin University of Traditional Chinese Medicine, Tianjin, PR China
| | - Haixia Wang
- College of Pharmaceutical Engineering of Traditional Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin, PR China
- State Key Laboratory of Component-based Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin, PR China
| | - Di Zhang
- College of Pharmaceutical Engineering of Traditional Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin, PR China
- State Key Laboratory of Component-based Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin, PR China
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Ferroptosis as a mechanism of non-ferrous metal toxicity. Arch Toxicol 2022; 96:2391-2417. [PMID: 35727353 DOI: 10.1007/s00204-022-03317-y] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Accepted: 05/11/2022] [Indexed: 11/02/2022]
Abstract
Ferroptosis is a recently discovered form of regulated cell death, implicated in multiple pathologies. Given that the toxicity elicited by some metals is linked to alterations in iron metabolism and induction of oxidative stress and lipid peroxidation, ferroptosis might be involved in such toxicity. Although direct evidence is insufficient, certain pioneering studies have demonstrated a crosstalk between metal toxicity and ferroptosis. Specifically, the mechanisms underlying metal-induced ferroptosis include induction of ferritinophagy, increased DMT-1 and TfR cellular iron uptake, mitochondrial dysfunction and mitochondrial reactive oxygen species (mitoROS) generation, inhibition of Xc-system and glutathione peroxidase 4 (GPX4) activity, altogether resulting in oxidative stress and lipid peroxidation. In addition, there is direct evidence of the role of ferroptosis in the toxicity of arsenic, cadmium, zinc, manganese, copper, and aluminum exposure. In contrast, findings on the impact of cobalt and nickel on ferroptosis are scant and nearly lacking altogether for mercury and especially lead. Other gaps in the field include limited studies on the role of metal speciation in ferroptosis and the critical cellular targets. Although further detailed studies are required, it seems reasonable to propose even at this early stage that ferroptosis may play a significant role in metal toxicity, and its modulation may be considered as a potential therapeutic tool for the amelioration of metal toxicity.
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Shandilya A, Mehan S, Kumar S, Sethi P, Narula AS, Alshammari A, Alharbi M, Alasmari AF. Activation of IGF-1/GLP-1 Signalling via 4-Hydroxyisoleucine Prevents Motor Neuron Impairments in Experimental ALS-Rats Exposed to Methylmercury-Induced Neurotoxicity. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27123878. [PMID: 35745001 PMCID: PMC9228431 DOI: 10.3390/molecules27123878] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/28/2022] [Revised: 06/13/2022] [Accepted: 06/14/2022] [Indexed: 12/11/2022]
Abstract
Amyotrophic lateral sclerosis (ALS) is a severe adult motor neuron disease that causes progressive neuromuscular atrophy, muscle wasting, weakness, and depressive-like symptoms. Our previous research suggests that mercury levels are directly associated with ALS progression. MeHg+-induced ALS is characterised by oligodendrocyte destruction, myelin basic protein (MBP) depletion, and white matter degeneration, leading to demyelination and motor neuron death. The selection of MeHg+ as a potential neurotoxicant is based on our evidence that it has been connected to the development of ALS-like characteristics. It causes glutamate-mediated excitotoxicity, calcium-dependent neurotoxicity, and an ALS-like phenotype. Dysregulation of IGF-1/GLP-1 signalling has been associated with ALS progression. The bioactive amino acid 4-hydroxyisoleucine (HI) from Trigonella foenum graecum acts as an insulin mimic in rodents and increases insulin sensitivity. This study examined the neuroprotective effects of 4-HI on MeHg+-treated adult Wistar rats with ALS-like symptoms, emphasising brain IGF1/GLP-1 activation. Furthermore, we investigated the effect of 4-HI on MBP levels in rat brain homogenate, cerebrospinal fluid (CSF), blood plasma, and cell death indicators such as caspase-3, Bax, and Bcl-2. Rats were assessed for muscular strength, locomotor deficits, depressed behaviour, and spatial learning in the Morris water maze (MWM) to measure neurobehavioral abnormalities. Doses of 4-HI were given orally for 42 days in the MeHg+ rat model at 50 mg/kg or 100 mg/kg to ameliorate ALS-like neurological dysfunctions. Additionally, neurotransmitters and oxidative stress markers were examined in rat brain homogenates. Our findings suggest that 4-HI has neuroprotective benefits in reducing MeHg+-induced behavioural, neurochemical, and histopathological abnormalities in ALS-like rats exposed to methylmercury.
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Affiliation(s)
- Ambika Shandilya
- Division of Neuroscience, Department of Pharmacology, ISF College of Pharmacy, Moga 142001, Punjab, India; (A.S.); (S.K.); (P.S.)
| | - Sidharth Mehan
- Division of Neuroscience, Department of Pharmacology, ISF College of Pharmacy, Moga 142001, Punjab, India; (A.S.); (S.K.); (P.S.)
- Correspondence:
| | - Sumit Kumar
- Division of Neuroscience, Department of Pharmacology, ISF College of Pharmacy, Moga 142001, Punjab, India; (A.S.); (S.K.); (P.S.)
| | - Pranshul Sethi
- Division of Neuroscience, Department of Pharmacology, ISF College of Pharmacy, Moga 142001, Punjab, India; (A.S.); (S.K.); (P.S.)
| | - Acharan S. Narula
- Narula Research, LLC, 107 Boulder Bluff, Chapel Hill, NC 27516, USA;
| | - Abdulrahman Alshammari
- Department of Pharmacology and Toxicology, College of Pharmacy, King Saud University, Post Box 2455, Riyadh 11451, Saudi Arabia; (A.A.); (M.A.); (A.F.A.)
| | - Metab Alharbi
- Department of Pharmacology and Toxicology, College of Pharmacy, King Saud University, Post Box 2455, Riyadh 11451, Saudi Arabia; (A.A.); (M.A.); (A.F.A.)
| | - Abdullah F. Alasmari
- Department of Pharmacology and Toxicology, College of Pharmacy, King Saud University, Post Box 2455, Riyadh 11451, Saudi Arabia; (A.A.); (M.A.); (A.F.A.)
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Huang CH, Wang FT, Chan WH. Low-dose silver nanoparticles plus methyl mercury exert embryotoxic effects on mouse blastocysts via endoplasmic reticulum stress and mitochondrial apoptosis. Toxicol Res (Camb) 2022; 11:460-474. [PMID: 35782646 PMCID: PMC9244727 DOI: 10.1093/toxres/tfac028] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 04/29/2022] [Accepted: 05/02/2022] [Indexed: 07/30/2023] Open
Abstract
The health and environmental impacts of the increasing commercial use of silver nanoparticles (AgNPs) are a growing concern. Methyl mercury (MeHg) is a potent toxin that biotransforms from mercury or inorganic mercury compounds in waterways and causes dangerous environmental contamination. However, the potential interactions and combined effects of AgNPs and MeHg are yet to be established. In the current study, we showed that low/non-embryotoxic doses of AgNPs and MeHg interact synergistically to induce embryotoxicity and further explored the underlying mechanisms affecting mouse embryo development. Notably, co-treatment with noncytotoxic concentrations of AgNPs (10 μM) and MeHg (0.1 μM) triggered apoptotic processes and embryotoxicity in mouse blastocysts and evoked intracellular reactive oxygen species (ROS) generation, which was effectively blocked by preincubation with 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid (trolox), a classic antioxidant. Further experiments demonstrated that ROS serve as a key upstream inducer of endoplasmic reticulum (ER) stress and mitochondria-dependent apoptotic processes in AgNP/MeHg-induced injury of mouse embryo implantation and pre- and postimplantation development. Our results collectively indicate that AgNP and MeHg at non-embryotoxic concentrations can synergistically evoke ROS, ultimately causing embryotoxicity through promotion of ER stress and mitochondria-dependent apoptotic signaling cascades.
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Affiliation(s)
- Chien-Hsun Huang
- Department of Obstetrics and Gynecology, Taoyuan General Hospital, Ministry of Health & Welfare, Zhongshan Road, Taoyuan District, Taoyuan City 33004, Taiwan
| | - Fu-Ting Wang
- Rehabilitation and Technical Aid Center, Taipei Veterans General Hospital, Section 2, Shipai Road, Beitou District, Taipei City 11217, Taiwan
| | - Wen-Hsiung Chan
- Corresponding author: Department of Bioscience Technology and Center for Nanotechnology, Chung Yuan Christian University, Zhongbei Road, Zhongli District, Taoyuan City 32023, Taiwan.
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Wang L, Yu L, Ge H, Bu Y, Sun M, Huang D, Wang S. A novel reversible dual-mode probe based on amorphous carbon nanodots for the detection of mercury ion and glutathione. Microchem J 2022. [DOI: 10.1016/j.microc.2022.107181] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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Nielsen T, Crawford N, Martell M, Khalil B, Imtiaz F, Newell-Caito JL, Caito S. MicroRNA Expression Influences Methylmercury-Induced Lipid Accumulation and Mitochondrial Toxicity in Caenorhabditis elegans. Chem Res Toxicol 2021; 35:77-88. [PMID: 34905692 DOI: 10.1021/acs.chemrestox.1c00306] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Metabolic effects of methylmercury (MeHg) are gaining wider attention. We have previously shown that MeHg causes lipid dysregulation in Caenorhabditis elegans (C. elegans), leading to altered gene expression, increased triglyceride levels and lipid storage, and altered feeding behaviors. Transcriptional regulators, such as transcription factors and microRNAs (miRNAs), have been shown to regulate lipid storage, serum triglycerides, and adipogenic gene expression in human and rodent models of metabolic diseases. As we recently investigated adipogenic transcription factors induced by MeHg, we were, therefore, interested in whether MeHg may also regulate miRNA sequences to cause metabolic dysfunction. Lipid dysregulation, as measured by triglyceride levels, lipid storage sites, and feeding behaviors, was assessed in wild-type (N2) worms and in transgenic worms that either were sensitive to miRNA expression or were unable to process miRNAs. Worms that were sensitive to the miRNA expression were protected from MeHg-induced lipid dysregulation. In contrast, the mutant worms that were unable to process miRNAs had exacerbated MeHg-induced lipid dysregulation. Concurrent with differential lipid homeostasis, miRNA-expression mutants had altered MeHg-induced mitochondrial toxicity as compared to N2, with the miRNA-sensitive mutants showing mitochondrial protection and the miRNA-processing mutants showing increased mitotoxicity. Taken together, our data demonstrate that the expression of miRNAs is an important determinant in MeHg toxicity and MeHg-induced metabolic dysfunction in C. elegans.
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Affiliation(s)
- Tyson Nielsen
- Department of Basic Pharmaceutical Sciences, School of Pharmacy, Husson University, Bangor, Maine 04401, United States
| | - Nicole Crawford
- Department of Basic Pharmaceutical Sciences, School of Pharmacy, Husson University, Bangor, Maine 04401, United States
| | - Megan Martell
- Department of Basic Pharmaceutical Sciences, School of Pharmacy, Husson University, Bangor, Maine 04401, United States
| | - Belal Khalil
- Department of Basic Pharmaceutical Sciences, School of Pharmacy, Husson University, Bangor, Maine 04401, United States
| | - Farooq Imtiaz
- Department of Basic Pharmaceutical Sciences, School of Pharmacy, Husson University, Bangor, Maine 04401, United States
| | - Jennifer L Newell-Caito
- Department of Molecular and Biomedical Sciences, University of Maine, Orono, Maine 04469, United States
| | - Samuel Caito
- Department of Basic Pharmaceutical Sciences, School of Pharmacy, Husson University, Bangor, Maine 04401, United States
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Alam M, Yadav RK, Minj E, Tiwari A, Mehan S. Exploring Molecular Approaches in Amyotrophic Lateral Sclerosis: Drug Targets from Clinical and Pre-Clinical Findings. Curr Mol Pharmacol 2021; 14:263-280. [PMID: 32342825 DOI: 10.2174/1566524020666200427214356] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Revised: 12/24/2019] [Accepted: 12/26/2019] [Indexed: 11/22/2022]
Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal motor neuron disease (MND) characterized by the death of upper and lower motor neurons (corticospinal tract) in the motor cortex, basal ganglia, brain stem, and spinal cord. The patient experiences the sign and symptoms between 55 to 75 years of age, which include impaired motor movement, difficulty in speaking and swallowing, grip loss, muscle atrophy, spasticity, and sometimes associated with memory and cognitive impairments. Median survival is 3 to 5 years after diagnosis and 5 to 10% of the patients live for more than 10 years. The limited intervention of pharmacologically active compounds, that are used clinically, is majorly associated with the narrow therapeutic index. Pre-clinically established experimental models, where neurotoxin methyl mercury mimics the ALS like behavioural and neurochemical alterations in rodents associated with neuronal mitochondrial dysfunctions and downregulation of adenyl cyclase mediated cAMP/CREB, is the main pathological hallmark for the progression of ALS in central as well in the peripheral nervous system. Despite the considerable investigation into neuroprotection, it still constrains treatment choices to strong care and organization of ALS complications. Therefore, this current review specially targeted the investigation of clinical and pre-clinical features available for ALS to understand the pathogenic mechanisms and to explore the pharmacological interventions associated with the up-regulation of intracellular adenyl cyclase/cAMP/ CREB and activation of mitochondrial-ETC coenzyme-Q10 as a future drug target in the amelioration of ALS mediated motor neuronal dysfunctions.
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Affiliation(s)
- Mamtaj Alam
- Department of Pharmacology, ISF College of Pharmacy, Moga-142001, Punjab, India
| | - Rajeshwar K Yadav
- Department of Pharmacology, ISF College of Pharmacy, Moga-142001, Punjab, India
| | - Elizabeth Minj
- Department of Pharmacology, ISF College of Pharmacy, Moga-142001, Punjab, India
| | - Aarti Tiwari
- Department of Pharmacology, ISF College of Pharmacy, Moga-142001, Punjab, India
| | - Sidharth Mehan
- Department of Pharmacology, ISF College of Pharmacy, Moga-142001, Punjab, India
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The Role of Human LRRK2 in Acute Methylmercury Toxicity in Caenorhabditis elegans. Neurochem Res 2021; 46:2991-3002. [PMID: 34272628 DOI: 10.1007/s11064-021-03394-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2021] [Revised: 06/28/2021] [Accepted: 07/01/2021] [Indexed: 10/20/2022]
Abstract
Methylmercury (MeHg) exposure and its harmful effects on the developing brain continue to be a global environmental health concern. Decline in mitochondrial function is central to the toxic effects of MeHg and pathogenesis of mitochondria-related diseases including Parkinson's disease (PD). LRRK2 (Leucine-rich repeat kinase 2) mutation is one of the most common genetic risk factors for PD. In this study, we utilize an acute toxicity model of MeHg exposure in the model organism Caenorhabditis elegans (C. elegans) to compare lifespan, developmental progression, mitochondrial membrane potential and reactive oxygen species (ROS) between the wild-type N2 strain, wild-type LRRK2 transgenic strain (WLZ1), and mutant LRRK2(G2019S) transgenic strain (WLZ3). Additionally, the expression levels of skn-1 and gst-4 were investigated. Our results show that acute MeHg exposure (5 and 10 µM) caused a significant developmental delay in the N2 and WLZ3 worms. Notably, the worms expressing wild-type LRRK2 were resistant to 5 µM MeHg- induced developmental retardation. ROS levels in response to MeHg exposure were increased in the N2 worms, but not in the WLZ1 or WLZ3 worms. The mitochondrial membrane potential was decreased in the N2 worms but increased in the WLZ1 and WLZ3 worms following MeHg exposure. Furthermore, MeHg exposure increased the expression of skn-1 in N2, but not in WLZ1 worms. Although skn-1 expression was increased in the WLZ3 worms following MeHg exposure, gst-4 expression was not induced. Both skn-1 and gst-4 had higher basal expression levels in LRRK2s transgenic than wild-type N2 worms. Knocking down of skn-1 with feeding RNAi had a significant developmental effect in WLZ1 worms; however, the effect was not found in WLZ3 worms. These results suggest that mitochondrial dysfunction and a defect in the SKN-1 signaling in the LRRK2 G2019S worms contribute to the severe developmental delay, establishing a modulatory role of LRRK2 mutation in MeHg-induced acute toxicity.
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Yuan L, Shi X, Tang BZ, Wang WX. Real-time in vitro monitoring of the subcellular toxicity of inorganic Hg and methylmercury in zebrafish cells. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2021; 236:105859. [PMID: 34004410 DOI: 10.1016/j.aquatox.2021.105859] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2020] [Revised: 04/19/2021] [Accepted: 05/01/2021] [Indexed: 06/12/2023]
Abstract
Mercury (Hg) is a prominent environmental contaminant and can cause various subcellular effects. Elucidating the different subcellular toxicities of inorganic Hg (Hg2+) and methylmercury (MeHg) is critical for understanding their overall cytotoxicity. In this study, we employed aggregation-induced emission (AIE) probes to investigate the toxicity of Hg at the subcellular level using an aquatic embryonic zebrafish fibroblast cell line ZF4 as a model. The dynamic monitoring of lysosomal pH and the mapping of pH distribution during Hg2+ or MeHg exposure were successfully realized for the first time. We found that both Hg2+ and MeHg decreased the mean lysosomal pH, but with contrasting effects and mechanisms. Hg2+ had a greater impact on lysosomal pH than MeHg at a similar intracellular concentration. In addition, Hg2+ in comparison to MeHg exposure led to an increased number of lysosomes, probably because of their different effects on autophagy. We further showed that MeHg (200 nM) exposure had an inverse effect on mitochondrial respiratory function. A high dose (1000 nM) of Hg2+ increased the amount of intracellular lipid droplets by 13%, indicating that lipid droplets may potentially play a role in Hg2+detoxification. Our study suggested that, compared with other parameters, lysosome pH was most sensitive to Hg2+ and MeHg. Therefore, lysosomal pH can be used as a potential biomarker to assess the cellular toxicity of Hg in vitro.
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Affiliation(s)
- Liuliang Yuan
- Division of Life Science, Hong Kong University of Science and Technology, Clearwater Bay, Kowloon, Hong Kong, China; School of Energy and Environment and State Key Laboratory of Marine Pollution, City University of Hong Kong, Kowloon, Hong Kong, China
| | - Xiujuan Shi
- Department of Chemistry, Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction, HKUST, Clear Water Bay, Kowloon, Hong Kong, China
| | - Ben Zhong Tang
- Department of Chemistry, Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction, HKUST, Clear Water Bay, Kowloon, Hong Kong, China
| | - Wen-Xiong Wang
- School of Energy and Environment and State Key Laboratory of Marine Pollution, City University of Hong Kong, Kowloon, Hong Kong, China; Research Centre for the Oceans and Human Health, City University of Hong Kong Shenzhen Research Institute, Shenzhen518057, China.
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Li B, Qiao C, Jin X, Chan HM. Characterizing the Low-Dose Effects of Methylmercury on the Early Stages of Embryo Development Using Cultured Human Embryonic Stem Cells. ENVIRONMENTAL HEALTH PERSPECTIVES 2021; 129:77007. [PMID: 34328791 PMCID: PMC8323991 DOI: 10.1289/ehp7349] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 06/18/2021] [Accepted: 07/02/2021] [Indexed: 06/13/2023]
Abstract
BACKGROUND Global concerns of methylmercury (MeHg) exposure have been raised, especially on its effects on pregnant women. Recent epidemiological studies have revealed associations between maternal blood/hair MeHg concentrations, adverse pregnancy outcomes, and developmental deficits. However, the underlying mechanisms remain unclear. OBJECTIVES In this study, we characterized the effects of MeHg exposure on undifferentiated human embryonic stem cells (hESCs) and extrapolated the effects to human embryonic development. METHODS hESCs were exposed to 0, 1, 5, 10, 50, 100 or 200nM MeHg for 24 h or 6 d. Cell adherence and colony formation and expansion were examined under the microscope. Cell attachment, viability/proliferation, apoptosis, stress response, cell cycle, autophagy, and expression of cell lineage marker genes and proteins were measured at the end of exposures. RESULTS Our results indicated that exposure to nanomolar concentrations of MeHg was associated with a) higher levels of reactive oxygen species (ROS) and hemeoxygenase-1 (HO-1), suggesting increased stress and adaptive responses; b) lower cellular adhesion, viability/proliferation, and colony formation and expansion; c) higher levels of apoptosis, reflected by higher cleaved caspase-3 expression and Annexin V binding; d) higher levels of cytoskeleton protein α-tubulin expression; e) higher rates of G1/S phase cell cycle arrest; and f) autophagy inhibition, as shown by a lower LC3BII/LC3BI ratio and accumulation of SQSTM1 (p62). These outcomes were accompanied by higher expressions of self-renewal genes or proteins or both, including OCT4, SOX2, NANOG, and cytokine receptor IL6ST, as well as pluripotency and the cell fate regulator cyclin D1. DISCUSSION These results revealed that under the selection pressure of exposure to low doses of MeHg, some hESCs underwent apoptosis, whereas others adapted and survived with enhanced self-renewal gene expression and specific morphological phenotypes. Findings from the present study provide in vitro evidence that low doses of MeHg adversely affect hESCs when exposed during a period of time that models embryonic pre-, during, and early postimplantation stages. https://doi.org/10.1289/EHP7349.
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Affiliation(s)
- Bai Li
- Department of Biology, University of Ottawa, Ottawa, Ontario, Canada
| | - Cunye Qiao
- Biostatistics and Modeling Division, Bureau of Food Surveillance and Science Integration, Food Directorate, Health Products and Food Branch (HPFB), Health Canada, Ottawa, Ontario, Canada
| | - Xiaolei Jin
- Regulatory Toxicology Research Division, Bureau of Chemical Safety, Food Directorate, HPFB, Health Canada, Ottawa, Ontario, Canada
| | - Hing Man Chan
- Department of Biology, University of Ottawa, Ottawa, Ontario, Canada
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Novo JP, Martins B, Raposo RS, Pereira FC, Oriá RB, Malva JO, Fontes-Ribeiro C. Cellular and Molecular Mechanisms Mediating Methylmercury Neurotoxicity and Neuroinflammation. Int J Mol Sci 2021; 22:ijms22063101. [PMID: 33803585 PMCID: PMC8003103 DOI: 10.3390/ijms22063101] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2021] [Revised: 03/06/2021] [Accepted: 03/15/2021] [Indexed: 02/06/2023] Open
Abstract
Methylmercury (MeHg) toxicity is a major environmental concern. In the aquatic reservoir, MeHg bioaccumulates along the food chain until it is consumed by riverine populations. There has been much interest in the neurotoxicity of MeHg due to recent environmental disasters. Studies have also addressed the implications of long-term MeHg exposure for humans. The central nervous system is particularly susceptible to the deleterious effects of MeHg, as evidenced by clinical symptoms and histopathological changes in poisoned humans. In vitro and in vivo studies have been crucial in deciphering the molecular mechanisms underlying MeHg-induced neurotoxicity. A collection of cellular and molecular alterations including cytokine release, oxidative stress, mitochondrial dysfunction, Ca2+ and glutamate dyshomeostasis, and cell death mechanisms are important consequences of brain cells exposure to MeHg. The purpose of this review is to organize an overview of the mercury cycle and MeHg poisoning events and to summarize data from cellular, animal, and human studies focusing on MeHg effects in neurons and glial cells. This review proposes an up-to-date compendium that will serve as a starting point for further studies and a consultation reference of published studies.
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Affiliation(s)
- João P. Novo
- Institute for Clinical and Biomedical Research (iCBR), Center for Innovative Biomedicine and Biotechnology (CIBB), and Institute of Pharmacology and Experimental Therapeutics, Faculty of Medicine, University of Coimbra, 3000-548 Coimbra, Portugal; (J.P.N.); (B.M.); (R.S.R.); (F.C.P.)
| | - Beatriz Martins
- Institute for Clinical and Biomedical Research (iCBR), Center for Innovative Biomedicine and Biotechnology (CIBB), and Institute of Pharmacology and Experimental Therapeutics, Faculty of Medicine, University of Coimbra, 3000-548 Coimbra, Portugal; (J.P.N.); (B.M.); (R.S.R.); (F.C.P.)
| | - Ramon S. Raposo
- Institute for Clinical and Biomedical Research (iCBR), Center for Innovative Biomedicine and Biotechnology (CIBB), and Institute of Pharmacology and Experimental Therapeutics, Faculty of Medicine, University of Coimbra, 3000-548 Coimbra, Portugal; (J.P.N.); (B.M.); (R.S.R.); (F.C.P.)
- Experimental Biology Core, University of Fortaleza, Health Sciences, Fortaleza 60110-001, Brazil
| | - Frederico C. Pereira
- Institute for Clinical and Biomedical Research (iCBR), Center for Innovative Biomedicine and Biotechnology (CIBB), and Institute of Pharmacology and Experimental Therapeutics, Faculty of Medicine, University of Coimbra, 3000-548 Coimbra, Portugal; (J.P.N.); (B.M.); (R.S.R.); (F.C.P.)
| | - Reinaldo B. Oriá
- Laboratory of Tissue Healing, Ontogeny and Nutrition, Department of Morphology and Institute of Biomedicine, School of Medicine, Federal University of Ceará, Fortaleza 60430-270, Brazil;
| | - João O. Malva
- Institute for Clinical and Biomedical Research (iCBR), Center for Innovative Biomedicine and Biotechnology (CIBB), and Institute of Pharmacology and Experimental Therapeutics, Faculty of Medicine, University of Coimbra, 3000-548 Coimbra, Portugal; (J.P.N.); (B.M.); (R.S.R.); (F.C.P.)
- Correspondence: (J.O.M.); (C.F.-R.)
| | - Carlos Fontes-Ribeiro
- Institute for Clinical and Biomedical Research (iCBR), Center for Innovative Biomedicine and Biotechnology (CIBB), and Institute of Pharmacology and Experimental Therapeutics, Faculty of Medicine, University of Coimbra, 3000-548 Coimbra, Portugal; (J.P.N.); (B.M.); (R.S.R.); (F.C.P.)
- Correspondence: (J.O.M.); (C.F.-R.)
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Branco V, Aschner M, Carvalho C. Neurotoxicity of mercury: an old issue with contemporary significance. ADVANCES IN NEUROTOXICOLOGY 2021; 5:239-262. [PMID: 34263092 PMCID: PMC8276940 DOI: 10.1016/bs.ant.2021.01.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Mercury exerts a variety of toxic effects, depending on the specific compound and route of exposure. However, neurotoxicity in virtue of its consequence to health causes the greatest concern for toxicologists. This is particularly true regarding fetal development, where neurotoxic effects are much more severe than in adults, and the toxicity threshold is lower. Here, we review the major concepts regarding the neurotoxicity of mercury compounds (mercury vapor; methylmercury and ethylmercury), from exposure routes to toxicokinetic particularities leading to brain deposition and the development of neurotoxic effects. Albeit research on the neurotoxicity of mercury compounds has significantly advanced from the second half of the twentieth century onwards, several grey areas regarding the mechanism of toxicity still exist. Thus, we emphasize research advances during the last two decades concerning the molecular interactions of mercury which cause neurotoxic effects. Highlights include the disruption of glutamate signaling and excitotoxicity resulting from exposure to mercury and the interaction with redox active residues such as cysteines and selenocysteines which are the premise accounting for the disruption of redox homeostasis caused by mercurials. We also address how immunotoxic effects at the CNS, namely microglia and astrocyte activation modulate developmental neurotoxicity, a major topic in contemporary research.
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Affiliation(s)
- Vasco Branco
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal
| | - Michael Aschner
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, USA
| | - Cristina Carvalho
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal
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Tanaka J, Kiyoshi K, Kadokura T, Suzuki KI, Nakayama S. Elucidation of the enzyme involved in 2,3,5-triphenyl tetrazolium chloride (TTC) staining activity and the relationship between TTC staining activity and fermentation profiles in Saccharomyces cerevisiae. J Biosci Bioeng 2020; 131:396-404. [PMID: 33386278 DOI: 10.1016/j.jbiosc.2020.12.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 12/01/2020] [Accepted: 12/01/2020] [Indexed: 10/22/2022]
Abstract
2,3,5-Triphenyl tetrazolium chloride (TTC) staining is a method to distinguish the mitochondrial activity of cells based on the color: colorless TTC turns red when under reducing conditions. Although the assay reflects the mitochondrial activity of cells, which enzyme(s) in the electron transport system contribute to TTC reduction has been unclear. TTC staining assays using gene disruptants related to the electron transport system in Saccharomyces cerevisiae revealed those disruptants related to electron transport from each electron donor to ubiquinone (red colonies) and disruptants that were related to ubiquinol-cytochrome c oxidoreductase and cytochrome c oxidase (white colonies). In addition, when the enzyme activities of ubiquinol-cytochrome c oxidoreductase and cytochrome c oxidase were measured using TTC as the electron acceptor, only ubiquinol-cytochrome c oxidoreductase showed TTC reduction activity, and the activity was enhanced by potassium cyanide, an inhibitor of cytochrome c oxidase. These results indicated that ubiquinol-cytochrome c oxidoreductase is involved in TTC reduction in S. cerevisiae. The fermentation profiles of BY4741UΔcor1 and BY4741UΔcox4, which exhibited no TTC staining activity, were almost identical to that of the parental strain BY4741U. However, cell growth and ethanol and succinate production of the ura3-mutated strain BY4741, which also exhibited no TTC staining activity, was altered compared to those of BY4741U, indicating that the fermentation profile varies among strains that show no TTC staining activity. The relationship between uracil metabolism and TTC staining activity was also determined based on metabolome analysis.
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Affiliation(s)
- Jumpei Tanaka
- Department of Fermentation Science and Technology, Faculty of Applied Bioscience, Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya-ku, Tokyo 156-8502, Japan
| | - Keiji Kiyoshi
- Department of Biochemistry and Applied Bioscience, Faculty of Agriculture, University of Miyazaki, 1-1 Gakuenkibanadainishi, Miyazaki-shi, Miyazaki 889-2192, Japan
| | - Toshimori Kadokura
- Department of Fermentation Science and Technology, Faculty of Applied Bioscience, Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya-ku, Tokyo 156-8502, Japan
| | - Ken-Ichiro Suzuki
- Department of Fermentation Science and Technology, Faculty of Applied Bioscience, Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya-ku, Tokyo 156-8502, Japan
| | - Shunichi Nakayama
- Department of Fermentation Science and Technology, Faculty of Applied Bioscience, Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya-ku, Tokyo 156-8502, Japan.
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Fujimura M, Usuki F. Methylmercury-Mediated Oxidative Stress and Activation of the Cellular Protective System. Antioxidants (Basel) 2020; 9:antiox9101004. [PMID: 33081221 PMCID: PMC7602710 DOI: 10.3390/antiox9101004] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 10/09/2020] [Accepted: 10/14/2020] [Indexed: 12/17/2022] Open
Abstract
Methylmercury (MeHg) is a well-known neurotoxicant that causes severe intoxication in humans. In Japan, it is referred to as Minamata disease, which involves two characteristic clinical forms: fetal type and adult type depending on the exposed age. In addition to MeHg burden level, individual susceptibility to MeHg plays a role in the manifestation of MeHg toxicity. Research progress has pointed out the importance of oxidative stress in the pathogenesis of MeHg toxicity. MeHg has a high affinity for selenohydryl groups, sulfhydryl groups, and selenides. It has been clarified that such affinity characteristics cause the impairment of antioxidant enzymes and proteins, resulting in the disruption of antioxidant systems. Furthermore, MeHg-induced intracellular selenium deficiency due to the greater affinity of MeHg for selenohydryl groups and selenides leads to failure in the recoding of a UGA codon for selenocysteine and results in the degradation of antioxidant selenoenzyme mRNA by nonsense-mediated mRNA decay. The defect of antioxidant selenoenzyme replenishment exacerbates MeHg-mediated oxidative stress. On the other hand, it has also been revealed that MeHg can directly activate the antioxidant Keap1/Nrf2 signaling pathway. This review summarizes the incidence of MeHg-mediated oxidative stress from the viewpoint of the individual intracellular redox system interactions and the MeHg-mediated aforementioned intracellular events. In addition, the mechanisms of cellular stress pathways and neuronal cell death triggered by MeHg-mediated oxidative stress and direct interactions of MeHg with reactive residues of proteins are mentioned.
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Affiliation(s)
- Masatake Fujimura
- Department of Basic Medical Sciences, National Institute for Minamata Disease, Kumamoto 867-0008, Japan;
| | - Fusako Usuki
- Division of Neuroimmunology, Joint Research Center for Human Retrovirus Infection, Kagoshima University, Kagoshima 890-8544, Japan
- Correspondence: ; Tel.: +81-99-275-6246; Fax: +81-99-275-5942
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Chen Z, Liu J, Tian L, Zhang Q, Guan Y, Chen L, Liu G, Yu HQ, Tian Y, Huang Q. Raman micro-spectroscopy monitoring of cytochrome c redox state in Candida utilis during cell death under low-temperature plasma-induced oxidative stress. Analyst 2020; 145:3922-3930. [PMID: 32307505 DOI: 10.1039/d0an00507j] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Oxidative stress may result in different modes of cell death, such as necrosis, apoptosis and necroptosis. Currently, researchers are still striving to develop efficient tools/methods to distinguish the cell death modes in direct and label-free ways. In this study, we attempted to employ Raman micro-spectroscopy to observe the molecular changes in Candida utilis cells under oxidative stress induced by low-temperature plasma (LTP) and explore the spectroscopic biomarkers for the modes of cell death under oxidative stress. In this research, we confirmed that LTP could impose oxidative stress on the yeast cells, and recorded the changes of Raman signals of cytochrome c in the cells under LTP oxidative stress. Subsequently, we identified the biochemical and morphological characteristic features corresponding to different modes of cell death. Interestingly, we found that LTP under certain conditions could induce oxidative stress which caused the yeast cell death mainly by means of necroptosis, which was verified by Annexin V/PI, HMGB1 location assay and immunoprecipitation assay of the RIP1/RIP3 necrosome. Correspondingly, we also showed that the LTP induced necroptosis, associated with the increase of cytoplasmic Ca2+ and mitochondrial ROS, the decrease of mitochondrial membrane potential, the release of oxidized cytochrome c from the mitochondrion to the cytoplasm, and the destruction of mitochondria in yeast cells. This work has therefore demonstrated that monitoring the redox state of cytochrome c using Raman micro-spectroscopy is very useful for distinguishing the modes of cell death and particularly may unveil the unique necroptosis process of cells under extrinsic oxidative stress.
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Affiliation(s)
- Zhu Chen
- Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, China.
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Li YK, Yang T, Chen ML, Wang JH. Recent Advances in Nanomaterials for Analysis of Trace Heavy Metals. Crit Rev Anal Chem 2020; 51:353-372. [PMID: 32182101 DOI: 10.1080/10408347.2020.1736505] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
In an effort to achieve high sensitivity analysis methods for ultra-trace levels of heavy metals, numerous new nanomaterials are explored for the application in preconcentration processes and sensing systems. Nanomaterial-based methods have proven to be effective for selective analysis and speciation of heavy metals in combination with spectrometric techniques. This review outlined the different types of nanomaterials applied in the field of heavy metal analysis, and concentrated on the latest developments in various new materials. In particular, the functionalization of traditional materials and the exploitation of bio-functional materials could increase the specificity to target metals. The hybridization of multiple materials could improve material properties, to build novel sensor system or achieve detection-removal integration. Finally, we discussed the future perspectives of nanomaterials in the heavy metal preconcentration and sensor design, as well as their respective advantages and challenges. Despite impressive progress and widespread attention, the development of new nanomaterials and nanotechnology is still hampered by numerous challenges, particularly in the specificity to the target and the anti-interference performance in complex matrices.
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Affiliation(s)
- Yi-Kun Li
- Research Center for Analytical Sciences, Department of Chemistry, College of Sciences, Northeastern University, Shenyang, China
| | - Ting Yang
- Research Center for Analytical Sciences, Department of Chemistry, College of Sciences, Northeastern University, Shenyang, China
| | - Ming-Li Chen
- Research Center for Analytical Sciences, Department of Chemistry, College of Sciences, Northeastern University, Shenyang, China.,Analytical and Testing Center, Northeastern University, Shenyang, China
| | - Jian-Hua Wang
- Research Center for Analytical Sciences, Department of Chemistry, College of Sciences, Northeastern University, Shenyang, China
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Ke T, Tsatsakis A, Santamaría A, Antunes Soare FA, Tinkov AA, Docea AO, Skalny A, Bowman AB, Aschner M. Chronic exposure to methylmercury induces puncta formation in cephalic dopaminergic neurons in Caenorhabditis elegans. Neurotoxicology 2020; 77:105-113. [PMID: 31935438 DOI: 10.1016/j.neuro.2020.01.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2019] [Revised: 01/08/2020] [Accepted: 01/08/2020] [Indexed: 01/09/2023]
Abstract
The neurotransmitter dopamine is a neuromodulator in the positive and negative regulation of brain circuits. Dopamine insufficiency or overload has been implicated in aberrant activities of neural circuits that play key roles in the pathogenesis of neurological and psychiatric diseases. Dopaminergic neurons are vulnerable to environmental insults. The neurotoxin methylmercury (MeHg) produces dopaminergic neuron damage in rodent as well as in Caenorhabditis elegans (C. elegans) models. Previous studies have demonstrated the utility of C. elegans as an alternative and complementary experimental model in dissecting out mechanism of MeHg-induced dopaminergic neurodegeneration. However, a sensitive pathological change that marks early events in neurodegeneration induced by environmental level of MeHg, is still lacking. By establishing a chronic exposure C. elegans model, for the first time, we have shown the propensity of MeHg (5 μM, 10 days) to induce bright puncta of dat-1::mCherry aggreagtes in the dendrites of cephalic (2 CEPs) dopaminergic neurons in a dose- and time-dependent manner, while these changes were not found in other dopaminergic neurons: anterior deirids (2 ADEs) and posterior deirids (2 PDEs), cholinergic neurons (2 AIYs) or glutamatergic neurons (2 PVDs). The bright puncta appear as an aggregation of mCherry proteins accumulating in dendrites. Further staining shows that the puncta were not inclusions in lysosome, or amyloid protein aggregates. In addition, features of the puncta including enlarged sphere shape (0.5-2 μm diameters), bright and accompanying with the shrinkage of the dendrite suggest that the puncta are likely composed of homologous mCherry molecules packaged at the dendritic site for exportation. Moreover, in the glutathione S-transferase 4 (gst-4) transcriptional reporter strain and RT-PCR assay, the expression levels of gst-4 and tubulins (tba-1 and tba-2) genes were not significantly modified under this chronic exposure paradigm, but gst-4 did show significant changes in an one day exposure paradigm. Collectively, these results suggest that CEP dopaminergic neurons are a sensitive target of MeHg, and the current exposure paradigm could be used as a model to investigate mechanism of dopaminergic neurotoxicity.
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Affiliation(s)
- Tao Ke
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY 10461, United States
| | - Aristidis Tsatsakis
- Laboratory of Toxicology and Forensic Sciences, Medical School, University of Crete, Heraklion, Greece
| | - Abel Santamaría
- Laboratorio de Aminoácidos Excitadores, Instituto Nacional de Neurología y Neurocirugía, 14269, Mexico City, Mexico
| | - Félix Alexandre Antunes Soare
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY 10461, United States; Department of Biochemistry and Molecular Biology, Federal University of Santa Maria, Santa Maria, RS, Brazil
| | - Alexey A Tinkov
- Yaroslavl State University, Sovetskaya St., 14, Yaroslavl 150000, Russia
| | - Anca Oana Docea
- Department of Toxicology, University of Medicine and Pharmacy, Faculty of Pharmacy, Craiova, 200349, Romania
| | - Anatoly Skalny
- Yaroslavl State University, Sovetskaya St., 14, Yaroslavl 150000, Russia; Peoples' Friendship University of Russia (RUDN University), Miklukho-Maklaya St., 6, Moscow 105064, Russia; Orenburg State University, Pobedy Ave., 13, Orenburg 460352, Russia
| | - Aaron B Bowman
- School of Health Sciences, Purdue University, West Lafayette, IN 47907-2051, United States
| | - Michael Aschner
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY 10461, United States; Peoples' Friendship University of Russia (RUDN University), Miklukho-Maklaya St., 6, Moscow 105064, Russia.
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Krishna Chandran AM, Christina H, Das S, Mumbrekar KD, Satish Rao BS. Neuroprotective role of naringenin against methylmercury induced cognitive impairment and mitochondrial damage in a mouse model. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2019; 71:103224. [PMID: 31376681 DOI: 10.1016/j.etap.2019.103224] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 07/09/2019] [Accepted: 07/21/2019] [Indexed: 06/10/2023]
Abstract
Human exposure to organomercurials like methylmercury (MeHg) may occur by consumption of contaminated seafood, affecting various vital organs especially, brain contributing to neuro disorders. The citrus flavanone, naringenin (NAR) has shown strong antioxidant and anti-inflammatory effects and therefore may exert cytoprotective effect against xenobiotic agents. Herein, we investigated the neuroprotective role of NAR against MeHg induced functional changes in mitochondria, neuronal cell death and cognitive impairment in a mouse model. A neurotoxic dose of MeHg (4 mg/kg.b.wt.) was administered orally to mice for 15 days. This resulted in the reduction of GSH and GST, an increase in mitochondrial DNA damage and memory impairment. On the contrary, NAR pre-treatment (100 mg/kg.b.wt.), helped in lowering the oxidative burden which in turn maintained mitochondrial function and prevented induced neuronal cell death, ultimately improving the cognitive impairment. As MeHg intoxication occurs chronically, consumption of the dietary components rich in NAR may have its positive human health impact, ultimately improving the quality of life.
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Affiliation(s)
- Adwaid Manu Krishna Chandran
- Department of Radiation Biology & Toxicology, Manipal School of Life Sciences, Manipal Academy of Higher Education, Manipal, 576 104, Karnataka, India
| | - Hannah Christina
- Department of Radiation Biology & Toxicology, Manipal School of Life Sciences, Manipal Academy of Higher Education, Manipal, 576 104, Karnataka, India
| | - Shubhankar Das
- Department of Radiation Biology & Toxicology, Manipal School of Life Sciences, Manipal Academy of Higher Education, Manipal, 576 104, Karnataka, India
| | - Kamalesh D Mumbrekar
- Department of Radiation Biology & Toxicology, Manipal School of Life Sciences, Manipal Academy of Higher Education, Manipal, 576 104, Karnataka, India
| | - B S Satish Rao
- Department of Radiation Biology & Toxicology, Manipal School of Life Sciences, Manipal Academy of Higher Education, Manipal, 576 104, Karnataka, India.
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Wang Y, Zhou S, Ma H, Shi JS, Lu YF. Investigation of the differential transport mechanism of cinnabar and mercury containing compounds. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2019; 66:83-90. [PMID: 30639899 DOI: 10.1016/j.etap.2018.12.020] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2018] [Revised: 12/01/2018] [Accepted: 12/24/2018] [Indexed: 06/09/2023]
Abstract
BACKGROUND Cinnabar has a long history of uses in Chinese traditional medicines as an ingredient in various remedies. However, the detailed mechanism of cinnabar in medication remains unclear, and the toxicity of cinnabar has been a debate due to its containing mercury sulfide. This study was designed to investigate the differential transport mechanism of cinnabar and other Hg-containing compounds HgCl2, MeHg and HgS, and to determine if organic anion transporters OAT1 and OAT3 were involved in the differential transport mechanism. MATERIALS AND METHODS The 293T cells were employed to investigate and compare the differential transport mechanism of cinnabar and HgCl2, MeHg and HgS. Cells were incubated with a low dose (5 μM HgCl2 and MeHg, 200 μM HgS and cinnabar), medium dose (10 μM HgCl2 and MeHg, 400 μM HgS and cinnabar), and high dose (20 μM HgCl2 and MeHg, 800 μM HgS and cinnabar) of HgCl2, MeHg, HgS and cinnabar for 24 h. Following treatment, the cells were collected and the cell viability was determined by MTT assay. The intracellular mercury content was measured at 1, 4, and 24 h after treatment with 10 μM of the tested agents by an atomic fluorescence spectrophotometer. The effect of these tested agents on mitochondrial respiration was determined in a high-resolution oxygraphyat 24 h following treatment. Furthermore, the effect of modulation of expression of transporters OAT1 and OAT3 on the transport and cytotoxicity of the tested agents was evaluated. The up and down regulation of OAT1 and OAT3 were achieved by overexpression and siRNA transfection, respectively. RESULTS Compared with HgCl2 and MeHg, the cytotoxicity of cinnabar and HgS was lower, with cell viability at the high dose cinnabar and HgS being about 65%, while MeHg and HgCl2 were 40% and 20%, respectively. The intracellular mercury accumulation was time-dependent. At 24 h the intracellular concentrations of HgCl2 and MeHg were about 7 and 5 times higher, respectively, than that of cinnabar. No significant difference was found in the intracellular mercury content in cells treated with cinnabar compared to HgS. The knockdown and overexpression of the transporter OAT1 resulted in significant reduction and increase, respectively, in mercury accumulation in HgCl2 -treated cells in relative to control cells, while no significant changes were observed in cells treated with cinnabar, MeHg, and HgS. In addition, the knockdown and overexpression of the transporter OAT3 caused significant reduction and increase, respectively, in mercury accumulation in both HgCl2 and MeHg-treated cells in relative to control cells, while no significant changes were observed in cells treated with cinnabar and HgS. Furthermore, it was found that cells transfected with siOAT1 caused significant resistance to the cytotoxicity induced by HgCl2, while no noticeable changes in cell viability were observed in cells treated with other tested agents. Additionally, cells transfected with OAT3 did not change cell sensitivity to cytotoxicity induced by all of the four tested agents. CONCLUSION This study demonstrates that differential transport and accumulation of mercury in 293T cells exists among cinnabar and the three mercury-containing compounds HgCl2, MeHg and HgS, leading to distinct sensitivity to mercury induced cytotoxicity. The kidney organic anion transporters OAT1 and OAT3 are partially involved in the regulation of the transport of HgCl2 and MeHg, but not in the regulation of the transport of cinnabar.
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Affiliation(s)
- Yang Wang
- Joint International Research Laboratory of Ethnomedicine, Key Laboratory of Basic Pharmacology of Ministry of Education, Zunyi Medical College, Guizhou, China
| | - Shaoyu Zhou
- Joint International Research Laboratory of Ethnomedicine, Key Laboratory of Basic Pharmacology of Ministry of Education, Zunyi Medical College, Guizhou, China; Department of Environmental Health, School of Public Health, Indiana University, Bloomington, IN, USA
| | - Honghong Ma
- Joint International Research Laboratory of Ethnomedicine, Key Laboratory of Basic Pharmacology of Ministry of Education, Zunyi Medical College, Guizhou, China
| | - Jing-Shan Shi
- Joint International Research Laboratory of Ethnomedicine, Key Laboratory of Basic Pharmacology of Ministry of Education, Zunyi Medical College, Guizhou, China
| | - Yuan-Fu Lu
- Joint International Research Laboratory of Ethnomedicine, Key Laboratory of Basic Pharmacology of Ministry of Education, Zunyi Medical College, Guizhou, China.
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Liu W, Yang T, Xu Z, Xu B, Deng Y. Methyl-mercury induces apoptosis through ROS-mediated endoplasmic reticulum stress and mitochondrial apoptosis pathways activation in rat cortical neurons. Free Radic Res 2018; 53:26-44. [DOI: 10.1080/10715762.2018.1546852] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- Wei Liu
- Department of Environmental Health, School of Public Health, China Medical University, Shenyang, People’s Republic of China
| | - Tianyao Yang
- Department of Environmental Health, School of Public Health, China Medical University, Shenyang, People’s Republic of China
| | - Zhaofa Xu
- Department of Environmental Health, School of Public Health, China Medical University, Shenyang, People’s Republic of China
| | - Bin Xu
- Department of Environmental Health, School of Public Health, China Medical University, Shenyang, People’s Republic of China
| | - Yu Deng
- Department of Environmental Health, School of Public Health, China Medical University, Shenyang, People’s Republic of China
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Sumathi T, Jacob S, Gopalakrishnan R. Methylmercury exposure develops atherosclerotic risk factors in the aorta and programmed cell death in the cerebellum: ameliorative action of Celastrus paniculatus ethanolic extract in male Wistar rats. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2018; 25:30212-30223. [PMID: 30155631 DOI: 10.1007/s11356-018-3031-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Accepted: 08/21/2018] [Indexed: 06/08/2023]
Abstract
Methylmercury (MeHg) is a bioaccumulative global environmental contaminant present in fishes and seafood. MeHg is the methylated form of mercury emitted from diverse anthropogenic and natural sources. MeHg is accumulated in the aquatic environment and eventually reaches human system via food chain by biomagnification. We have reported previously that the neurotoxic effect of MeHg in rat cerebellum is mitigated by the administration of an ayurvedic medicinal plant, Celastrus paniculatus ethanolic extract. The present study has focussed to further explore the mechanism of action of Celastrus paniculatus against MeHg-induced neurotoxicity in the cerebellum. We have also inspected the effect of Celastrus paniculatus (CP) against MeHg-induced atherosclerotic risk factors like alterations in antioxidant levels, aortic lipid profile, and aortic histology by MeHg in the largest vasculature, aorta, which are the initiating factors of cardiovascular diseases. Male Wistar rats were divided as (i) control, (ii) MeHg (5 mg/kg b.w.), (iii) MeHg + CP (200 mg/kg b.w.), and (iv) CP alone (200 mg/kg b.w.). All were given orally for 21 days. In cerebellum Celastrus paniculatus, there were increased mitochondrial electron transport chain (p < 0.05) activity, reduced cytochrome c release (p < 0.05), and caspase 3 mRNA expression (p < 0.05). In the aorta, MeHg-induced oxidative stress, lipid profile changes, and endothelial denudation were ameliorated by Celastrus paniculatus. Hence, we conclude that Celastrus paniculatus protects against MeHg toxicity by inhibiting mitochondrial cytochrome c/caspase 3 apoptotic pathway in the cerebellum and reducing the development of atherosclerotic risk factors in the aorta.
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Affiliation(s)
- Thangarajan Sumathi
- Department of Medical Biochemistry, Dr. ALM Post Graduate Institute of Basic Medical Sciences, University of Madras, Taramani Campus, Chennai, Tamil Nadu, 600113, India.
| | - Sherin Jacob
- Department of Medical Biochemistry, Dr. ALM Post Graduate Institute of Basic Medical Sciences, University of Madras, Taramani Campus, Chennai, Tamil Nadu, 600113, India
| | - Rahul Gopalakrishnan
- Department of Medical Biochemistry, Dr. ALM Post Graduate Institute of Basic Medical Sciences, University of Madras, Taramani Campus, Chennai, Tamil Nadu, 600113, India
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Pereira LC, de Paula ES, Pazin M, Carneiro MFH, Grotto D, Barbosa F, Dorta DJ. Niacin prevents mitochondrial oxidative stress caused by sub-chronic exposure to methylmercury. Drug Chem Toxicol 2018; 43:64-70. [PMID: 30192646 DOI: 10.1080/01480545.2018.1497045] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Humans and animals can be exposed to different chemical forms of mercury (Hg) in the environment. For example, methylmercury (MeHg)-contaminated fish is part of the basic diet of the riparian population in the Brazilian Amazon Basin, which leads to high total blood and plasma Hg levels in people living therein. Hg induces toxic effects mainly through oxidative stress. Different compounds have been used to prevent the damage caused by MeHg-induced reactive oxygen species (ROS). This study aims to investigate the in vivo effects of sub-chronic exposure to low MeHg levels on the mitochondrial oxidative status and to evaluate the niacin protective effect against MeHg-induced oxidative stress. For this purpose, Male Wistar rats were divided into four groups: control group, treated with drinking water on a daily basis; group exposed to MeHg at a dose of 100 µg/kg/day; group that received niacin at a dose of 50 mg/kg/day in drinking water, with drinking water being administered by gavage; group that received niacin at a dose of 50 mg/kg/day in drinking water as well as MeHg at a dose of 100 µg/kg/day. After 12 weeks, the rats, which weighed 500-550 g, were sacrificed, and their liver mitochondria were isolated by standard differential centrifugation. Sub-chronic exposure to MeHg (100 µg/kg/day for 12 weeks) led to mitochondrial swelling (p < 0.05) and induced ROS overproduction as determined by increased DFCH oxidation (p < 0.05), increased gluthatione oxidation (p < 0.05), and reduced protein thiol content (p < 0.05). In contrast, niacin supplementation inhibited oxidative stress, which counteracted and minimized the toxic MeHg effects on mitochondria.
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Affiliation(s)
- Lílian Cristina Pereira
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brasil.,Faculdade de Ciências Agronômicas, Departamento de Bioprocessos e Biotecnologia, Universidade Estadual Paulista, Botucatu, São Paulo, Brasil.,Departamento de Patologia, Faculdade de Medicina de Botucatu, Universidade Estadual Paulista, TOXICAM - Núcleo de Avaliação do Impacto Ambiental sobre a Saúde Humana, Botucatu, São Paulo, Brazil
| | - Eloisa Silva de Paula
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brasil
| | - Murilo Pazin
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brasil
| | - Maria Fernanda Hornos Carneiro
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brasil
| | - Denise Grotto
- Laboratório de Pesquisa em Toxicologia, Programa de Pós-Graduação em Ciências Farmacêuticas, Universidade de Sorocaba, Sorocaba, São Paulo, Brasil
| | - Fernando Barbosa
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brasil
| | - Daniel Junqueira Dorta
- Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Departamento de Química, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brasil.,Instituto Nacional de Tecnologias Alternativas de Detecção, Avaliação Toxicológica e Remoção de Micropututantes e Radioativos (INCT-DATREM), Unesp, Instituto de Química, Araraquara, São Paulo, Brasil
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Effect of Metallothionein-III on Mercury-Induced Chemokine Gene Expression. TOXICS 2018; 6:toxics6030048. [PMID: 30103553 PMCID: PMC6161308 DOI: 10.3390/toxics6030048] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Revised: 08/02/2018] [Accepted: 08/07/2018] [Indexed: 11/16/2022]
Abstract
Mercury compounds are known to cause central nervous system disorders; however the detailed molecular mechanisms of their actions remain unclear. Methylmercury increases the expression of several chemokine genes, specifically in the brain, while metallothionein-III (MT-III) has a protective role against various brain diseases. In this study, we investigated the involvement of MT-III in chemokine gene expression changes in response to methylmercury and mercury vapor in the cerebrum and cerebellum of wild-type mice and MT-III null mice. No difference in mercury concentration was observed between the wild-type mice and MT-III null mice in any brain tissue examined. The expression of Ccl3 in the cerebrum and of Cxcl10 in the cerebellum was increased by methylmercury in the MT-III null but not the wild-type mice. The expression of Ccl7 in the cerebellum was increased by mercury vapor in the MT-III null mice but not the wild-type mice. However, the expression of Ccl12 and Cxcl12 was increased in the cerebrum by methylmercury only in the wild-type mice and the expression of Ccl3 in the cerebellum was increased by mercury vapor only in the wild-type mice. These results indicate that MT-III does not affect mercury accumulation in the brain, but that it affects the expression of some chemokine genes in response to mercury compounds.
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Jacob S, Thangarajan S. Fisetin impedes developmental methylmercury neurotoxicity via downregulating apoptotic signalling pathway and upregulating Rho GTPase signalling pathway in hippocampus of F 1 generation rats. Int J Dev Neurosci 2018; 69:88-96. [PMID: 30009881 DOI: 10.1016/j.ijdevneu.2018.07.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Revised: 06/14/2018] [Accepted: 07/08/2018] [Indexed: 01/14/2023] Open
Abstract
Methyl mercury is a teratogenic and neurodevelopmental toxicant in the environment. MeHg affects several biological pathways critical for brain development. The present study validated the effect of Fisetin on developmental MeHg exposure induced alterations in mitochondrial apoptotic pathway and Rho GTPase mRNA expressions in hippocampus of F1 generation rats. Pregnant Wistar rats were grouped as Group I : administered with vehicle control, Group II: MeHg (1.5 mg/kg b.w), Group III: MeHg + Fisetin (10 mg/kg b.w), Group IV: MeHg + Fisetin (30 mg/kg b.w), Group V: MeHg + Fisetin (50 mg/kg b.w), Group VI: MeHg + Fisetin (70 mg/kg b.w), Group VII: Fisetin (30 mg/kg b.w) alone. Fisetin reduced mercury accumulation in offspring brain. In hippocampus, Fisetin preserved mitochondrial total thiol status, glutathione antioxidant system, mitochondrial metabolic integrity and respiratory chain activity. Fisetin ameliorated apoptotic signals by preventing Cytochrome c release, down regulating ERK 1/2 and Caspase 3 gene expression. Fisetin also upregulated mRNA expressions of RhoA/Rac1/Cdc42 in hippocampus. Predominant effect of Fisetin was to reduce mercury accumulation in offspring brain there by diminishing the toxic effect of MeHg. Hence we showed that, gestational intake of Fisetin (30 mg/kg b.w.) impedes developmental MeHg neurotoxicity by regulating mitochondrial apoptotic and Rho GTPase signalling molecules and by reducing the mercury accumulation in hippocampus of F1 generation rats.
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Affiliation(s)
- Sherin Jacob
- Dr.ALMPG IBMS, University of Madras, Taramani Campus, Chennai, 600113, Tamil Nadu, India
| | - Sumathi Thangarajan
- Dr.ALMPG IBMS, University of Madras, Taramani Campus, Chennai, 600113, Tamil Nadu, India.
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31
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Prince LM, Rand MD. Methylmercury exposure causes a persistent inhibition of myogenin expression and C2C12 myoblast differentiation. Toxicology 2017; 393:113-122. [PMID: 29104120 DOI: 10.1016/j.tox.2017.11.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Revised: 10/03/2017] [Accepted: 11/01/2017] [Indexed: 12/11/2022]
Abstract
Methylmercury (MeHg) is a ubiquitous environmental toxicant, best known for its selective targeting of the developing nervous system. MeHg exposure has been shown to cause motor deficits such as impaired gait and coordination, muscle weakness, and muscle atrophy, which have been associated with disruption of motor neurons. However, recent studies have suggested that muscle may also be a target of MeHg toxicity, both in the context of developmental myogenic events and of low-level chronic exposures affecting muscle wasting in aging. We therefore investigated the effects of MeHg on myotube formation, using the C2C12 mouse myoblast model. We found that MeHg inhibits both differentiation and fusion, in a concentration-dependent manner. Furthermore, MeHg specifically and persistently inhibits myogenin (MyoG), a transcription factor involved in myocyte differentiation, within the first six hours of exposure. MeHg-induced reduction in MyoG expression is contemporaneous with a reduction of a number of factors involved in mitochondrial biogenesis and mtDNA transcription and translation, which may implicate a role for mitochondria in mediating MeHg-induced change in the differentiation program. Unexpectedly, inhibition of myoblast differentiation with MeHg parallels inhibition of Notch receptor signaling. Our research establishes muscle cell differentiation as a target for MeHg toxicity, which may contribute to the underlying etiology of motor deficits with MeHg toxicity.
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Affiliation(s)
- Lisa M Prince
- University of Rochester School of Medicine and Dentistry, 601 Elmwood Avenue, Department of Environmental Medicine, Rochester, NY, 14642, USA.
| | - Matthew D Rand
- University of Rochester School of Medicine and Dentistry, 601 Elmwood Avenue, Department of Environmental Medicine, Rochester, NY, 14642, USA.
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32
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The Putative Role of Environmental Mercury in the Pathogenesis and Pathophysiology of Autism Spectrum Disorders and Subtypes. Mol Neurobiol 2017; 55:4834-4856. [DOI: 10.1007/s12035-017-0692-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2017] [Accepted: 07/13/2017] [Indexed: 01/28/2023]
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Memantine, a Low-Affinity NMDA Receptor Antagonist, Protects against Methylmercury-Induced Cytotoxicity of Rat Primary Cultured Cortical Neurons, Involvement of Ca2+ Dyshomeostasis Antagonism, and Indirect Antioxidation Effects. Mol Neurobiol 2016; 54:5034-5050. [DOI: 10.1007/s12035-016-0020-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Accepted: 08/01/2016] [Indexed: 01/20/2023]
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Abstract
Cerebellar disorders trigger the symptoms of movement problems, imbalance, incoordination, and frequent fall. Cerebellar disorders are shown in various CNS illnesses including a drinking disorder called alcoholism. Alcoholism is manifested as an inability to control drinking in spite of adverse consequences. Human and animal studies have shown that cerebellar symptoms persist even after complete abstinence from drinking. In particular, the abrupt termination (ethanol withdrawal) of long-term excessive ethanol consumption has shown to provoke a variety of neuronal and mitochondrial damage to the cerebellum. Upon ethanol withdrawal, excitatory neurotransmitter molecules such as glutamate are overly released in brain areas including cerebellum. This is particularly relevant to the cerebellar neuronal network as glutamate signals are projected to Purkinje neurons through granular cells that are the most populated neuronal type in CNS. This excitatory neuronal signal may be elevated by ethanol withdrawal stress, which promotes an increase in intracellular Ca(2+) level and a decrease in a Ca(2+)-binding protein, both of which result in the excessive entry of Ca(2+) to the mitochondria. Subsequently, mitochondria undergo a prolonged opening of mitochondrial permeability transition pore and the overproduction of harmful free radicals, impeding adenosine triphosphate (ATP)-generating function. This in turn provokes the leakage of mitochondrial molecule cytochrome c to the cytosol, which triggers a cascade of adverse cytosol reactions. Upstream to this pathway, cerebellum under the condition of ethanol withdrawal has shown aberrant gene modifications through altered DNA methylation, histone acetylation, or microRNA expression. Interplay between these events and molecules may result in functional damage to cerebellar mitochondria and consequent neuronal degeneration, thereby contributing to motoric deficit. Mitochondria-targeting research may help develop a powerful new therapy to manage cerebellar disorders associated with hyperexcitatory CNS disorders like ethanol withdrawal.
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Affiliation(s)
- Marianna E Jung
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center at Fort Worth, 3500 Camp Bowie Blvd., Fort Worth, TX, 76107-2699, USA,
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35
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Caito SW, Aschner M. NAD+ Supplementation Attenuates Methylmercury Dopaminergic and Mitochondrial Toxicity in Caenorhabditis Elegans. Toxicol Sci 2016; 151:139-49. [PMID: 26865665 DOI: 10.1093/toxsci/kfw030] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Methylmercury (MeHg) is a neurotoxic contaminant of our fish supply that has been linked to dopaminergic (DAergic) dysfunction that characterizes Parkinson's disease. We have previously shown that MeHg causes both morphological and behavioral changes in the Caenorhabditis elegans DAergic neurons that are associated with oxidative stress. We were therefore interested in whether the redox sensitive cofactor nicotinamide adenine dinucleotide (NAD(+)) may be affected by MeHg and whether supplementation of NAD( + )may prevent MeHg-induced toxicities. Worms treated with MeHg showed depletion in cellular NAD( + )levels, which was prevented by NAD( + )supplementation prior to MeHg treatment. NAD( + )supplementation also prevented DAergic neurodegeneration and deficits in DAergic-dependent behavior upon MeHg exposure. In a mutant worm line that cannot synthesize NAD( + )from nicotinamide, MeHg lethality and DAergic behavioral deficits were more sensitive to MeHg than wildtype worms, demonstrating the importance of NAD( + )in MeHg toxicity. In wildtype worms, NAD( + )supplementation provided protection from MeHg-induced oxidative stress and mitochondrial dysfunction. These data show the importance of NAD( + )levels in the response to MeHg exposure. NAD( + )supplementation may be beneficial for MeHg-induced toxicities and preventing cellular damage involved in Parkinson's disease.
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Affiliation(s)
- Samuel W Caito
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, New York 10461
| | - Michael Aschner
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, New York 10461
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Dysregulation of Glutamate Cycling Mediates Methylmercury-Induced Neurotoxicity. ADVANCES IN NEUROBIOLOGY 2016; 13:295-305. [PMID: 27885634 DOI: 10.1007/978-3-319-45096-4_11] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
To examine the toxicological implications of glutamate, this chapter will focus specifically on its impact in the brain. More explicitly, it will illustrate the role glutamate plays in mediating methylmercury (MeHg)-induced neurotoxicity. In this chapter, one intends to highlight the processes that occur prior to glutamate-stimulated excitotoxicity and subsequent neurodegeneration. As such, it will emphasize three main routes by which MeHg alters glutamate homeostasis. It is essential to recognize that these effects are not mutually exclusive, and that they synergistically influence glutamate dysregulation. Furthermore, the consequences of MeHg exposure will be presented here as a direct pathway; however, it must be noted these effects occur simultaneously. First, glutamate uptake will be reviewed emphasizing the function of astrocytes. Next, the induction of oxidative stress by MeHg exposure will be discussed. This process has a two-fold effect on glutamate homeostasis by (1) inhibiting extracellular glutamate uptake and (2) altering transcription of genes vital to glutamate cycling. Finally, the impact glutamate dysregulation has on glutathione synthesis will be examined. Although this chapter centers on the link between glutamate and MeHg toxicity, it is imperative that the reader acknowledges the processes discussed here can be extended to any pro-oxidant.
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Abstract
SIGNIFICANCE Mitochondria are structurally and biochemically diverse, even within a single type of cell. Protein complexes localized to the inner mitochondrial membrane synthesize ATP by coupling electron transport and oxidative phosphorylation. The organelles produce reactive oxygen species (ROS) from mitochondrial oxygen and ROS can, in turn, alter the function and expression of proteins used for aerobic respiration by post-translational and transcriptional regulation. RECENT ADVANCES New interest is emerging not only into the roles of mitochondria in disease development and progression but also as a target for environmental toxicants. CRITICAL ISSUES Dysregulation of respiration has been linked to cell death and is a major contributor to acute neuronal trauma, peripheral diseases, as well as chronic neurodegenerative diseases, such as Parkinson's disease and Alzheimer's disease. FUTURE DIRECTIONS Here, we discuss the mechanisms underlying the sensitivity of the mitochondrial respiratory complexes to redox modulation, as well as examine the effects of environmental contaminants that have well-characterized mitochondrial toxicity. The contaminants discussed in this review are some of the most prevalent and potent environmental contaminants that have been linked to neurological dysfunction, altered cellular respiration, and oxidation.
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Affiliation(s)
- Samuel W Caito
- Department of Molecular Pharmacology, Albert Einstein College of Medicine , Bronx, New York
| | - Michael Aschner
- Department of Molecular Pharmacology, Albert Einstein College of Medicine , Bronx, New York
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Truong J, Mailloux RJ, Chan HM. Impact of methylmercury exposure on mitochondrial energetics in AC16 and H9C2 cardiomyocytes. Toxicol In Vitro 2015; 29:953-61. [PMID: 25835517 DOI: 10.1016/j.tiv.2015.03.016] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2015] [Revised: 03/23/2015] [Accepted: 03/25/2015] [Indexed: 10/23/2022]
Abstract
It has been reported that chronic low dose exposures of methylmercury (MeHg) is associated with cardiovascular diseases in many populations worldwide. The toxic mechanisms through which these adverse effects occur are currently unknown. The objective of this study was to determine the bioenergetic and cytotoxic effects of MeHg on AC16 and H9C2 cardiomyocyte cell lines. Both cell lines exhibit significantly decreased mitochondrial function, cell viability and increased reactive oxygen species (ROS) production. Decreases in maximal respiration and reserve capacity was observed in both cell lines at 1μM. Bioenergetic profile experiments were also performed in tandem with cells exposed to diamide or menadione, compounds which accumulate in mitochondria and disrupt oxidative phosphorylation. AC16 cells show MeHg dose dependant sensitivities with Stateapparent and ATP production values, but H9C2 cells do not show these trends. H9C2 cells may be more resistant to MeHg toxicity than AC16 cells as reflected in the increases of proton leak and Stateapparent. No changes in expression of respiratory complexes were observed. Results suggest that MeHg has the potential to induce cytotoxicity. Furthermore, MeHg may have differential effects on AC16 and H9C2 cells, derived from human and rat cardiac tissue respectively, suggesting that differences in MeHg toxicity may be species-dependent.
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Affiliation(s)
- Jocelyn Truong
- Center for Advanced Research in Environmental Genomics, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| | - Ryan J Mailloux
- Center for Advanced Research in Environmental Genomics, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| | - Hing Man Chan
- Center for Advanced Research in Environmental Genomics, University of Ottawa, Ottawa, ON K1N 6N5, Canada.
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Tiernan CT, Edwin EA, Hawong HY, Ríos-Cabanillas M, Goudreau JL, Atchison WD, Lookingland KJ. Methylmercury impairs canonical dopamine metabolism in rat undifferentiated pheochromocytoma (PC12) cells by indirect inhibition of aldehyde dehydrogenase. Toxicol Sci 2015; 144:347-56. [PMID: 25601988 DOI: 10.1093/toxsci/kfv001] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The environmental neurotoxicant methylmercury (MeHg) disrupts dopamine (DA) neurochemical homeostasis by stimulating DA synthesis and release. Evidence also suggests that DA metabolism is independently impaired. The present investigation was designed to characterize the DA metabolomic profile induced by MeHg, and examine potential mechanisms by which MeHg inhibits the DA metabolic enzyme aldehyde dehydrogenase (ALDH) in rat undifferentiated PC12 cells. MeHg decreases the intracellular concentration of 3,4-dihydroxyphenylacetic acid (DOPAC). This is associated with a concomitant increase in intracellular concentrations of the intermediate metabolite 3,4-dihydroxyphenylaldehyde (DOPAL) and the reduced metabolic product 3,4-dihydroxyethanol. This metabolomic profile is consistent with inhibition of ALDH, which catalyzes oxidation of DOPAL to DOPAC. MeHg does not directly impair ALDH enzymatic activity, however MeHg depletes cytosolic levels of the ALDH cofactor NAD(+), which could contribute to impaired ALDH activity following exposure to MeHg. The observation that MeHg shunts DA metabolism along an alternative metabolic pathway and leads to the accumulation of DOPAL, a reactive species associated with protein and DNA damage, as well as cell death, is of significant consequence. As a specific metabolite of DA, the observed accumulation of DOPAL provides evidence for a specific mechanism by which DA neurons may be selectively vulnerable to MeHg.
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Affiliation(s)
- Chelsea T Tiernan
- *Neuroscience Program, Department of Pharmacology and Toxicology, Department of Biochemistry and Molecular Biology, College of Osteopathic Medicine and Department of Neurology and Ophthalmology, Michigan State University, East Lansing, Michigan 48824
| | - Ethan A Edwin
- *Neuroscience Program, Department of Pharmacology and Toxicology, Department of Biochemistry and Molecular Biology, College of Osteopathic Medicine and Department of Neurology and Ophthalmology, Michigan State University, East Lansing, Michigan 48824
| | - Hae-Young Hawong
- *Neuroscience Program, Department of Pharmacology and Toxicology, Department of Biochemistry and Molecular Biology, College of Osteopathic Medicine and Department of Neurology and Ophthalmology, Michigan State University, East Lansing, Michigan 48824 *Neuroscience Program, Department of Pharmacology and Toxicology, Department of Biochemistry and Molecular Biology, College of Osteopathic Medicine and Department of Neurology and Ophthalmology, Michigan State University, East Lansing, Michigan 48824
| | - Mónica Ríos-Cabanillas
- *Neuroscience Program, Department of Pharmacology and Toxicology, Department of Biochemistry and Molecular Biology, College of Osteopathic Medicine and Department of Neurology and Ophthalmology, Michigan State University, East Lansing, Michigan 48824
| | - John L Goudreau
- *Neuroscience Program, Department of Pharmacology and Toxicology, Department of Biochemistry and Molecular Biology, College of Osteopathic Medicine and Department of Neurology and Ophthalmology, Michigan State University, East Lansing, Michigan 48824 *Neuroscience Program, Department of Pharmacology and Toxicology, Department of Biochemistry and Molecular Biology, College of Osteopathic Medicine and Department of Neurology and Ophthalmology, Michigan State University, East Lansing, Michigan 48824 *Neuroscience Program, Department of Pharmacology and Toxicology, Department of Biochemistry and Molecular Biology, College of Osteopathic Medicine and Department of Neurology and Ophthalmology, Michigan State University, East Lansing, Michigan 48824
| | - William D Atchison
- *Neuroscience Program, Department of Pharmacology and Toxicology, Department of Biochemistry and Molecular Biology, College of Osteopathic Medicine and Department of Neurology and Ophthalmology, Michigan State University, East Lansing, Michigan 48824 *Neuroscience Program, Department of Pharmacology and Toxicology, Department of Biochemistry and Molecular Biology, College of Osteopathic Medicine and Department of Neurology and Ophthalmology, Michigan State University, East Lansing, Michigan 48824
| | - Keith J Lookingland
- *Neuroscience Program, Department of Pharmacology and Toxicology, Department of Biochemistry and Molecular Biology, College of Osteopathic Medicine and Department of Neurology and Ophthalmology, Michigan State University, East Lansing, Michigan 48824 *Neuroscience Program, Department of Pharmacology and Toxicology, Department of Biochemistry and Molecular Biology, College of Osteopathic Medicine and Department of Neurology and Ophthalmology, Michigan State University, East Lansing, Michigan 48824
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Xu X, Li YF, Zhao J, Li Y, Lin J, Li B, Gao Y, Chen C. Nanomaterial-based approaches for the detection and speciation of mercury. Analyst 2015; 140:7841-53. [DOI: 10.1039/c5an01519g] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Detection and speciation of Hg through the T–Hg–T coordination, Hg–S and/or Hg–Au/Ag interactions based colorimetric or fluorescent changes.
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Affiliation(s)
- Xiaohan Xu
- CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety
- and State Environmental Protection Engineering Center for Mercury Pollution Prevention and Control
- Institute of High Energy Physics
- Chinese Academy of Sciences
- Beijing 100049
| | - Yu-Feng Li
- CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety
- and State Environmental Protection Engineering Center for Mercury Pollution Prevention and Control
- Institute of High Energy Physics
- Chinese Academy of Sciences
- Beijing 100049
| | - Jiating Zhao
- CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety
- and State Environmental Protection Engineering Center for Mercury Pollution Prevention and Control
- Institute of High Energy Physics
- Chinese Academy of Sciences
- Beijing 100049
| | - Yunyun Li
- CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety
- and State Environmental Protection Engineering Center for Mercury Pollution Prevention and Control
- Institute of High Energy Physics
- Chinese Academy of Sciences
- Beijing 100049
| | - Jing Lin
- CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety
- and State Environmental Protection Engineering Center for Mercury Pollution Prevention and Control
- Institute of High Energy Physics
- Chinese Academy of Sciences
- Beijing 100049
| | - Bai Li
- CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety
- and State Environmental Protection Engineering Center for Mercury Pollution Prevention and Control
- Institute of High Energy Physics
- Chinese Academy of Sciences
- Beijing 100049
| | - Yuxi Gao
- CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety
- and State Environmental Protection Engineering Center for Mercury Pollution Prevention and Control
- Institute of High Energy Physics
- Chinese Academy of Sciences
- Beijing 100049
| | - Chunying Chen
- National Center for Nanoscience and Technology
- Beijing 100190
- China
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Abstract
Metals are frequently used in industry and represent a major source of toxin exposure for workers. For this reason governmental agencies regulate the amount of metal exposure permissible for worker safety. While essential metals serve physiologic roles, metals pose significant health risks upon acute and chronic exposure to high levels. The central nervous system is particularly vulnerable to metals. The brain readily accumulates metals, which under physiologic conditions are incorporated into essential metalloproteins required for neuronal health and energy homeostasis. Severe consequences can arise from circumstances of excess essential metals or exposure to toxic nonessential metal. Herein, we discuss sources of occupational metal exposure, metal homeostasis in the human body, susceptibility of the nervous system to metals, detoxification, detection of metals in biologic samples, and chelation therapeutic strategies. The neurologic pathology and physiology following aluminum, arsenic, lead, manganese, mercury, and trimethyltin exposures are highlighted as classic examples of metal-induced neurotoxicity.
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Affiliation(s)
- Samuel Caito
- Division of Clinical Pharmacology and Pediatric Toxicology, Vanderbilt University Medical Center, Nashville, TN, USA; The Kennedy Center for Research on Human Development, Vanderbilt University Medical Center, Nashville, TN, USA.
| | - Michael Aschner
- Division of Clinical Pharmacology and Pediatric Toxicology, Vanderbilt University Medical Center, Nashville, TN, USA; The Kennedy Center for Research on Human Development, Vanderbilt University Medical Center, Nashville, TN, USA; Center in Molecular Toxicology, Vanderbilt University Medical Center, Nashville, TN, USA; Center for Molecular Neuroscience, Vanderbilt University Medical Center, Nashville, TN, USA
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Pieper I, Wehe CA, Bornhorst J, Ebert F, Leffers L, Holtkamp M, Höseler P, Weber T, Mangerich A, Bürkle A, Karst U, Schwerdtle T. Mechanisms of Hg species induced toxicity in cultured human astrocytes: genotoxicity and DNA-damage response. Metallomics 2014; 6:662-71. [PMID: 24549367 DOI: 10.1039/c3mt00337j] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
The toxicologically most relevant mercury (Hg) species for human exposure is methylmercury (MeHg). Thiomersal is a common preservative used in some vaccine formulations. The aim of this study is to get further mechanistic insight into the yet not fully understood neurotoxic modes of action of organic Hg species. Mercury species investigated include MeHgCl and thiomersal. Additionally HgCl2 was studied, since in the brain mercuric Hg can be formed by dealkylation of the organic species. As a cellular system astrocytes were used. In vivo astrocytes provide the environment necessary for neuronal function. In the present study, cytotoxic effects of the respective mercuricals increased with rising alkylation level and correlated with their cellular bioavailability. Further experiments revealed for all species at subcytotoxic concentrations no induction of DNA strand breaks, whereas all species massively increased H2O2-induced DNA strand breaks. This co-genotoxic effect is likely due to a disturbance of the cellular DNA damage response. Thus, at nanomolar, sub-cytotoxic concentrations, all three mercury species strongly disturbed poly(ADP-ribosyl)ation, a signalling reaction induced by DNA strand breaks. Interestingly, the molecular mechanism behind this inhibition seems to be different for the species. Since chronic PARP-1 inhibition is also discussed to sacrifice neurogenesis and learning abilities, further experiments on neurons and in vivo studies could be helpful to clarify whether the inhibition of poly(ADP-ribosyl)ation contributes to organic Hg induced neurotoxicity.
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Affiliation(s)
- Imke Pieper
- Institute of Food Chemistry, University of Münster, Corrensstr. 45, 48149 Münster, Germany
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Patel E, Reynolds M. Methylmercury impairs motor function in early development and induces oxidative stress in cerebellar granule cells. Toxicol Lett 2013; 222:265-72. [DOI: 10.1016/j.toxlet.2013.08.002] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2013] [Revised: 07/31/2013] [Accepted: 08/03/2013] [Indexed: 01/20/2023]
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Lencesova L, Hudecova S, Csaderova L, Markova J, Soltysova A, Pastorek M, Sedlak J, Wood ME, Whiteman M, Ondrias K, Krizanova O. Sulphide signalling potentiates apoptosis through the up-regulation of IP3 receptor types 1 and 2. Acta Physiol (Oxf) 2013; 208:350-61. [PMID: 23582047 DOI: 10.1111/apha.12105] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2012] [Revised: 11/15/2012] [Accepted: 04/04/2013] [Indexed: 12/14/2022]
Abstract
AIM To investigate an interaction between the calcium and sulphide signalling pathways, particularly effects of the slow H2 S release donor morpholin-4-ium-4-methoxyphenyl-(morpholino)-phosphinodithioate (GYY4137) on the expression of inositol 1,4,5-trisphosphate receptors (IP3 R) with the possible impact on the apoptosis induction in HeLa cells. METHODS Gene expression, Western blot analysis, apoptosis determination by Annexin-V-FLUOS and drop in mitochondrial membrane potential by 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazolyl-carbocyanine iodide (JC1) and immunofluorescence were used to determine differences in control and GYY4137-treated HeLa cells. RESULTS In HeLa cell line, GYY4137 (10 μm) up-regulated expression of the IP3 R1 and IP3 R2, but not IP3 R3 on both mRNA and protein levels. Concurrently, cytosolic calcium increased and reticular calcium was depleted in concentration-dependent manner, partially by the involvement of IP3 R. Depletion of calcium from reticulum was accompanied by increase in endoplasmic reticulum (ER) stress markers, such as X-box, CHOP and ATF4, thus pointing to the development of ER stress due to GYY4137 treatment. Also, GYY4137 treatment of HeLa cells increased the number of apoptotic cells. CONCLUSION These results suggest an involvement of H2 S in both IP3 -induced calcium signalling and induction of apoptosis, possibly through the activation of ER stress.
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Affiliation(s)
- L. Lencesova
- Institute of Molecular Physiology and Genetics; Slovak Academy of Sciences; Bratislava; Slovak Republic
| | - S. Hudecova
- Institute of Molecular Physiology and Genetics; Slovak Academy of Sciences; Bratislava; Slovak Republic
| | - L. Csaderova
- Molecular Medicine Center; Slovak Academy of Sciences; Bratislava; Slovak Republic
| | - J. Markova
- Institute of Molecular Physiology and Genetics; Slovak Academy of Sciences; Bratislava; Slovak Republic
| | - A. Soltysova
- Institute of Molecular Physiology and Genetics; Slovak Academy of Sciences; Bratislava; Slovak Republic
| | - M. Pastorek
- Cancer Research Institute; Slovak Academy of Sciences; Bratislava; Slovak Republic
| | - J. Sedlak
- Cancer Research Institute; Slovak Academy of Sciences; Bratislava; Slovak Republic
| | - M. E. Wood
- Department of Biosciences; College of Life and Environmental Sciences; University of Exeter; Exeter; UK
| | - M. Whiteman
- University of Exeter Medical School; Exeter; UK
| | - K. Ondrias
- Institute of Molecular Physiology and Genetics; Slovak Academy of Sciences; Bratislava; Slovak Republic
| | - O. Krizanova
- Institute of Molecular Physiology and Genetics; Slovak Academy of Sciences; Bratislava; Slovak Republic
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45
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Lee JY, Hwang GW, Kim MS, Takahashi T, Naganuma A. Methylmercury induces a brain-specific increase in chemokine CCL4 expression in mice. J Toxicol Sci 2013. [PMID: 23208444 DOI: 10.2131/jts.37.1279] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Expression of the chemokine genes Ccl2, Ccl4, Ccl7, Ccl9, and Ccl12 is increased in cerebellum of mice treated with methylmercury. To investigate the effect of methylmercury on other tissues and organs, levels of chemokine mRNA were investigated in mouse cerebrum, kidney, liver, and spleen. In cerebrum, expression levels of the five chemokines were significantly increased after methylmercury treatment. In kidney, expression levels of Ccl2, Ccl7, Ccl9, and Ccl12, but not Ccl4 were increased. No significant effects were seen on mRNA levels of the chemokines in liver and spleen. Thus, although methylmercury increases the expression levels of multiple chemokines in the brain and kidney, expression of Ccl4 increases only in the brain. Hence, this phenomenon may be involved in methylmercury toxicity specific to the central nervous system.
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Affiliation(s)
- Jin-Yong Lee
- Laboratory of Molecular and Biochemical Toxicology, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan
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46
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Hwang GW, Kimura Y, Takahashi T, Lee JY, Naganuma A. Identification of deubiquitinating enzymes involved in methylmercury toxicity in Saccharomyces cerevisiae. J Toxicol Sci 2013. [PMID: 23208446 DOI: 10.2131/jts.37.1287] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Deubiquitinating enzymes that influence the methylmercury susceptibility of yeast cells were investigated. Deficiency of Ubp2, Ubp4, Ubp 6, or Ubp14 conferred methylmercury resistance on cells, while deficiency of Ubp7, Ubp13, or Ubp15 conferred high methylmercury susceptibility. Of these enzymes, deficiency of Ubp4 and Ubp6 was associated with particularly high methylmercury resistance. Yeast cells treated with a proteasome inhibitor showed methylmercury resistance due to Ubp4 deficiency, but not due to Ubp6 deficiency. Thus, the enhanced methylmercury toxicity associated with Ubp6 expression requires proteasomal activity, suggesting that Ubp4 and Ubp6 contribute to enhanced methylmercury toxicity through different mechanisms.
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Affiliation(s)
- Gi-Wook Hwang
- Laboratory of Molecular and Biochemical Toxicology, Graduate School of Pharmaceutical Sciences, Tohoku University, Miyagi, Japan
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Hwang GW, Lee JY, Kim MS, Sato M, Takahashi T, Naganuma A. Changes in the levels of low molecular weight metabolites in the mouse cerebellum following treatment with methylmercury. J Toxicol Sci 2013; 38:703-6. [DOI: 10.2131/jts.38.703] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- Gi-Wook Hwang
- Laboratory of Molecular and Biochemical Toxicology, Graduate School of Pharmaceutical Sciences, Tohoku University
| | - Jin-Yong Lee
- Laboratory of Molecular and Biochemical Toxicology, Graduate School of Pharmaceutical Sciences, Tohoku University
- Laboratory of Pharmaceutical Health Sciences, School of Pharmacy, Aichi Gakuin University
| | - Min-Seok Kim
- Laboratory of Molecular and Biochemical Toxicology, Graduate School of Pharmaceutical Sciences, Tohoku University
| | - Masayuki Sato
- Laboratory of Molecular and Biochemical Toxicology, Graduate School of Pharmaceutical Sciences, Tohoku University
| | - Tsutomu Takahashi
- Laboratory of Molecular and Biochemical Toxicology, Graduate School of Pharmaceutical Sciences, Tohoku University
| | - Akira Naganuma
- Laboratory of Molecular and Biochemical Toxicology, Graduate School of Pharmaceutical Sciences, Tohoku University
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RIP1-mediated mitochondrial dysfunction and ROS production contributed to tumor necrosis factor alpha-induced L929 cell necroptosis and autophagy. Int Immunopharmacol 2012; 14:674-82. [DOI: 10.1016/j.intimp.2012.08.003] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2012] [Revised: 08/02/2012] [Accepted: 08/03/2012] [Indexed: 11/21/2022]
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49
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Hassauer M, Kaiser E, Schneider K, Schuhmacher‐Wolz U. Collate the literature on toxicity data on mercury in experimental animals and humans (Part I – Data on organic mercury). ACTA ACUST UNITED AC 2012. [DOI: 10.2903/sp.efsa.2012.en-297] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Martin Hassauer
- Forschungs‐ und Beratungsinstitut Gefahrstoffe GmbH (FoBiG) Freiburg Germany
| | - Eva Kaiser
- Forschungs‐ und Beratungsinstitut Gefahrstoffe GmbH (FoBiG) Freiburg Germany
| | - Klaus Schneider
- Forschungs‐ und Beratungsinstitut Gefahrstoffe GmbH (FoBiG) Freiburg Germany
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50
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Scientific Opinion on the risk for public health related to the presence of mercury and methylmercury in food. EFSA J 2012. [DOI: 10.2903/j.efsa.2012.2985] [Citation(s) in RCA: 276] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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