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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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Barbosa NV, Aschner M, Tinkov AA, Farina M, da Rocha JBT. Should ebselen be considered for the treatment of mercury intoxication? A minireview. Toxicol Mech Methods 2024; 34:1-12. [PMID: 37731353 PMCID: PMC10841883 DOI: 10.1080/15376516.2023.2258958] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Accepted: 09/09/2023] [Indexed: 09/22/2023]
Abstract
Mercury is a ubiquitous environmental contaminant and can be found in inorganic (Hg0, Hg+ and Hg2+) and organic forms (chiefly CH3Hg+ or MeHg+). The main route of human, mammals and bird exposure occurs via predatory fish ingestion. Occupational exposure to Hg0 (and Hg2+) can also occur; furthermore, in gold mining areas the exposure to inorganic Hg can also be high. The toxicity of electrophilic forms of Hg (E+Hg) is mediated by disruption of thiol (-SH)- or selenol (-SeH)-containing proteins. The therapeutic approaches to treat methylmercury (MeHg+), Hg0 and Hg2+ are limited. Here we discuss the potential use of ebselen as a potential therapeutic agent to lower the body burden of Hg in man. Ebselen is a safe drug for humans and has been tested in clinical trials (for instance, brain ischemia, noise-induce hearing loss, diabetes complications, bipolar disorders) at doses varying from 400 to 3600 mg per day. Two clinical trials with ebselen in moderate and severe COVID are also approved. Ebselen can be metabolized to an intermediate with -SeH (selenol) functional group, which has a greater affinity to electrophilic Hg (E+Hg) forms than the available thiol-containing therapeutic agents. Accordingly, as observed in vitro and rodent models in vivo, Ebselen exhibited protective effects against MeHg+, indicating its potential as a therapeutic agent to treat MeHg+ overexposure. The combined use of ebselen with thiol-containing molecules (e.g. N-acetylcysteine and enaramide)) is also commented, because they can have synergistic protective effects against MeHg+.
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Affiliation(s)
- Nilda V. Barbosa
- Departamento de Bioquímica e Biologia Molecular, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Santa Maria, Brazil
| | - Michael Aschner
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Alexey A. Tinkov
- Yaroslavl State University, Yaroslavl, Russia
- Center of Bioelementology and Human Ecology, IM Sechenov First Moscow State Medical University (Sechenov University), Moscow, Russia
| | - Marcelo Farina
- Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, Brazil
| | - João Batista Teixeira da Rocha
- Departamento de Bioquímica e Biologia Molecular, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Santa Maria, Brazil
- Departamento de Bioquímica, Instituto Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
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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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Sasaki S, Negishi T, Tsuzuki T, Yukawa K. Methylmercury-induced reactive oxygen species-dependent and independent dysregulation of MAP kinase-related signaling pathway in cultured normal rat cerebellar astrocytes. Toxicology 2023; 487:153463. [PMID: 36813253 DOI: 10.1016/j.tox.2023.153463] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2022] [Revised: 02/17/2023] [Accepted: 02/17/2023] [Indexed: 02/22/2023]
Abstract
Methylmercury (MeHg), a global environmental pollutant, could seriously damage the central nervous system (CNS) and cause neurological disorders such as cerebellar symptoms. Although numerous studies have revealed detailed toxicity mechanisms of MeHg in neurons, toxicity in astrocytes is barely known. Here, we tried to shed light on the toxicity mechanisms of MeHg exposure in cultured normal rat cerebellar astrocytes (NRA), focusing on the involvement of reactive oxygen species (ROS) in MeHg toxicity by assessing the effects of major antioxidants Trolox, a free-radical scavenger, N-acetyl-L-cysteine (NAC), a potent thiol-containing antioxidant, and glutathione (GSH), an endogenous thiol-containing antioxidant. Exposure to MeHg at just approximately 2 µM for 96 h increased cell viability, which was accompanied by the increase in intracellular ROS level and at ≥ 5 µM induced significant cell death and lowered ROS level. Trolox and NAC suppressed 2 µM MeHg-induced increases in cell viability and ROS level corresponding to control, although GSH with 2 µM MeHg induced significant cell death and ROS increase. On the contrary, against 4 µM MeHg-induced cell loss and ROS decrease, NAC inhibited both cell loss and ROS decrease, Trolox inhibited cell loss and further enhanced ROS decrease, and GSH moderately inhibited cell loss and increased ROS level above the control level. MeHg-induced oxidative stress was suggested by increases in the protein expression levels of heme oxygenase-1 (HO-1), Hsp70, and Nrf2, except for the decrease in SOD-1 and no change in catalase. Furthermore, MeHg exposure dose-dependently induced increases in the phosphorylation of MAP kinases (ERK1/2, p38MAPK, and SAPK/JNK) and phosphorylation and/or expression levels of transcription factors (CREB, c-Jun, and c-Fos) in NRA. NAC successfully suppressed 2 µM MeHg-induced alterations in all of the above-mentioned MeHg-responsive factors, whereas Trolox suppressed some MeHg-responsive factors but failed to suppress MeHg-induced increases in the protein expression levels of HO-1 and Hsp70 and increase in p38MAPK phosphorylation. Protein expression analyses in NRA exposed to 2 µM MeHg and GSH were excluded because of devastating cell death. These results suggested that MeHg could induce aberrant NRA activation, and ROS must be substantially involved in the toxicity mechanism of MeHg in NRA; however, other factors should be assumed.
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Affiliation(s)
- Shoto Sasaki
- Department of Physiology, Graduate School of Pharmacy, Meijo University, 150 Yagotoyama, Tempaku-ku, Nagoya-shi, Aichi 468-8503, Japan
| | - Takayuki Negishi
- Department of Physiology, Graduate School of Pharmacy, Meijo University, 150 Yagotoyama, Tempaku-ku, Nagoya-shi, Aichi 468-8503, Japan; Department of Physiology, Faculty of Pharmacy, Meijo University, 150 Yagotoyama, Tempaku-ku, Nagoya-shi, Aichi 468-8503, Japan.
| | - Takamasa Tsuzuki
- Department of Physiology, Faculty of Pharmacy, Meijo University, 150 Yagotoyama, Tempaku-ku, Nagoya-shi, Aichi 468-8503, Japan
| | - Kazunori Yukawa
- Department of Physiology, Graduate School of Pharmacy, Meijo University, 150 Yagotoyama, Tempaku-ku, Nagoya-shi, Aichi 468-8503, Japan; Department of Physiology, Faculty of Pharmacy, Meijo University, 150 Yagotoyama, Tempaku-ku, Nagoya-shi, Aichi 468-8503, Japan
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Abdelhamid MS, El Bohi KM, Sherif MH, Abdelhamid MS, Abdel-Daim MM, Elewa YHA, Metwally MMM, Albadrani GM, Najda A, El Abdel-Hamid S, Abu-Zeid EH. Apitoxin alleviates methyl mercury-induced peripheral neurotoxicity in male rats by regulating dorsal root ganglia neuronal degeneration and oxidative stress. Biomed Pharmacother 2023; 161:114521. [PMID: 36921536 DOI: 10.1016/j.biopha.2023.114521] [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: 01/06/2023] [Revised: 03/02/2023] [Accepted: 03/09/2023] [Indexed: 03/16/2023] Open
Abstract
Methylmercury (MeHg) toxicity is associated with extensive neuronal degeneration of dorsal root ganglia (DRG). This study aimed to assess the ameliorative effect of bee venom (BV) on methyl mercury chloride (MeHgCl)-induced peripheral neurotoxicity using DRGs in rats. Forty-eight adult male Sprague Dawley rats were allocated into four equal groups: G I: control (gavaged MilliQ water 1 ml/rat), G II: subcutaneously injected with BV (0.5 mg/kg b.wt), G III: gavaged MeHgCl (6.7 mg/kg b.wt), and G IV: received MeHgCl+BV. Dosing was done five times/week for 2 weeks. Ataxic behavior and visual impairments were significantly increased, whereas the movement behavior and motility gait were suppressed in the MeHgCl group. MeHgCl significantly decreased total antioxidant capacity (TAC) in DRG and significantly decreased the serum levels of glutathione (GSH), catalase (CAT), and superoxide dismutase (SOD). Tumor necrosis factor-alpha (TNF-α) and interleukin 1β (IL-1β) levels were significantly elevated, whereas interleukin 10 (IL-10) levels were significantly decreased in the MeHgCl group compared with the control group. DRGs of the MeHgCl-exposed rats showed pyknotic shrunken neurons with perineural vacuolations, demyelination of nerve axons, and proliferation of the satellite cells. MeHgCl significantly induced a higher positive index ratio of Iba-1, SOX10, neurofilament, pan-neuron, and vimentin immunostaining in the DRG. BV administration significantly mitigated the MeHgCl-induced alterations in oxidative stress-related indices. BV modified the immunostaining of Iba-1, SOX10, neurofilament, pan-neuron, and vimentin-positive index ratio in the DRG of the MeHgCl group. Our findings acknowledged that BV could enhance in vivo neuroprotective effects against MeHgCl-induced DRGs damage in male rats.
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Affiliation(s)
- Moustafa S Abdelhamid
- Biochemistry division, Chemistry Department, Faculty of Science, Zagazig University, 44511, Egypt
| | - Khlood M El Bohi
- Department of Forensic Medicine and Toxicology, Faculty of Veterinary Medicine, Zagazig University, 44511, Egypt
| | - Mohamed H Sherif
- Biochemistry division, Chemistry Department, Faculty of Science, Zagazig University, 44511, Egypt
| | - Manar S Abdelhamid
- Biochemistry division, Chemistry Department, Faculty of Science, Zagazig University, 44511, Egypt
| | - Mohamed M Abdel-Daim
- Department of Pharmaceutical Sciences, Pharmacy Program, Batterjee Medical College, P.O. Box 6231, Jeddah 21442, Saudi Arabia; Pharmacology Department, Faculty of Veterinary Medicine, Suez Canal University, Ismailia 41522, Egypt
| | - Yaser H A Elewa
- Department of Histology and Cytology, Faculty of Veterinary Medicine, Zagazig University, 44511, Egypt; Laboratory of Anatomy, Department of Basic Veterinary Sciences, Faculty of Veterinary Medicine, Hokkaido University, Sapporo, Japan
| | - Mohamed M M Metwally
- Department of Pathology, Faculty of Veterinary Medicine, Zagazig University, Zagazig 44511, Egypt
| | - Ghadeer M Albadrani
- Department of Biology, College of Science, Princess Nourah bint Abdulrahman University, B.O. Box 84428, Riyadh 11671, Saudi Arabia
| | - Agnieszka Najda
- Department of Vegetable Crops and Medicinal Plants University of Life Sciences in Lublin, 50 A Doświadczalna Street, 20-280 Lublin, Poland.
| | - Shereen El Abdel-Hamid
- Department of Behavior and Management of Animal, Poultry and Aquatics, Faculty of Veterinary Medicine, Zagazig University, 44511, Egypt
| | - Ehsan H Abu-Zeid
- Department of Forensic Medicine and Toxicology, Faculty of Veterinary Medicine, Zagazig University, 44511, Egypt.
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Zuo K, Xu Q, Wang Y, Sui Y, Niu Y, Liu Z, Liu M, Liu X, Liu D, Sun W, Wang Z, Liu X, Liu J. L-Ascorbic Acid 2-Phosphate Attenuates Methylmercury-Induced Apoptosis by Inhibiting Reactive Oxygen Species Accumulation and DNA Damage in Human SH-SY5Y Cells. TOXICS 2023; 11:144. [PMID: 36851019 PMCID: PMC9967424 DOI: 10.3390/toxics11020144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Revised: 01/28/2023] [Accepted: 01/31/2023] [Indexed: 06/18/2023]
Abstract
Methylmercury (MeHg) is a toxin that causes severe neuronal oxidative damage. As vitamin C is an antioxidant well-known to protect neurons from oxidative damage, our goal was to elucidate its protective mechanism against MeHg-induced oxidative stress in human neuroblastomas (SHSY5Y). We treated cells with MeHg, L-ascorbic acid 2-phosphate (AA2P), or both, and used MTT, flow cytometry, and Western blot analyses to assess cell damage. We found that MeHg significantly decreased the survival rate of SH-SY5Y cells in a time- and dose-dependent manner, increased apoptosis, downregulated PAR and PARP1 expression, and upregulated AIF, Cyto C, and cleaved Caspase-3 expression. A time course study showed that MeHg increased reactive oxygen species (ROS) accumulation; enhanced apoptosis; increased DNA damage; upregulated expression ofγH2A.X, KU70, 67 and 57 kDa AIF, CytoC, and cleaved Caspase-3; and downregulated expression of 116 kDa PARP1, PAR, BRAC1, and Rad51. Supplementation with AA2P significantly increased cell viability and decreased intrinsic ROS accumulation. It also reduced ROS accumulation in cells treated with MeHg and decreased MeHg-induced apoptosis. Furthermore, AA2P conversely regulated gene expression compared to MeHg. Collectively, we demonstrate that AA2P attenuates MeHg-induced apoptosis by alleviating ROS-mediated DNA damage and is a potential treatment for MeHg neurotoxicity.
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Affiliation(s)
- Kuiyang Zuo
- Department of Toxicology, School of Public Health, Jilin University, 1163 Xinmin Avenue, Changchun 130021, China
| | - Qi Xu
- Department of Toxicology, School of Public Health, Jilin University, 1163 Xinmin Avenue, Changchun 130021, China
| | - Yujie Wang
- Department of Toxicology, School of Public Health, Jilin University, 1163 Xinmin Avenue, Changchun 130021, China
| | - Yutong Sui
- Department of Toxicology, School of Public Health, Jilin University, 1163 Xinmin Avenue, Changchun 130021, China
| | - Ye Niu
- Department of Toxicology, School of Public Health, Jilin University, 1163 Xinmin Avenue, Changchun 130021, China
| | - Zinan Liu
- Department of Toxicology, School of Public Health, Jilin University, 1163 Xinmin Avenue, Changchun 130021, China
| | - Mingsheng Liu
- Department of Toxicology, School of Public Health, Jilin University, 1163 Xinmin Avenue, Changchun 130021, China
| | - Xinpeng Liu
- Department of Toxicology, School of Public Health, Jilin University, 1163 Xinmin Avenue, Changchun 130021, China
| | - Dan Liu
- Department of Toxicology, School of Public Health, Jilin University, 1163 Xinmin Avenue, Changchun 130021, China
| | - Wei Sun
- Department of Toxicology, School of Public Health, Jilin University, 1163 Xinmin Avenue, Changchun 130021, China
| | - Ziyu Wang
- Department of Toxicology, School of Public Health, Jilin University, 1163 Xinmin Avenue, Changchun 130021, China
| | - Xiaomei Liu
- Department of Toxicology, School of Public Health, Jilin University, 1163 Xinmin Avenue, Changchun 130021, China
| | - Jinyu Liu
- Department of Toxicology, School of Public Health, Jilin University, 1163 Xinmin Avenue, Changchun 130021, China
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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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Pan J, Li X, Wei Y, Ni L, Xu B, Deng Y, Yang T, Liu W. Advances on the Influence of Methylmercury Exposure during Neurodevelopment. Chem Res Toxicol 2022; 35:43-58. [PMID: 34989572 DOI: 10.1021/acs.chemrestox.1c00255] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Mercury (Hg) is a toxic heavy-metal element, which can be enriched in fauna and flora and transformed into methylmercury (MeHg). MeHg is a widely distributed environmental pollutant that may be harmful to fish-eating populations through enrichment of aquatic food chains. The central nervous system is a primary target of MeHg. Embryos and infants are more sensitive to MeHg, and exposure to MeHg during gestational feeding can significantly impair the homeostasis of offspring, leading to long-term neurodevelopmental defects. At present, MeHg-induced neurodevelopmental toxicity has become a hotspot in the field of neurotoxicology, but its mechanisms are not fully understood. Some evidence point to oxidative damage, excitotoxicity, calcium ion imbalance, mitochondrial dysfunction, epigenetic changes, and other molecular mechanisms that play important roles in MeHg-induced neurodevelopmental toxicity. In this review, advances in the study of neurodevelopmental toxicity of MeHg exposure during pregnancy and the molecular mechanisms of related pathways are summarized, in order to provide more scientific basis for the study of neurodevelopmental toxicity of MeHg.
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Affiliation(s)
- Jingjing Pan
- Department of Environmental Health, School of Public Health, China Medical University, No.77 Puhe Road, Shenbei New District, Shenyang 110122, Liaoning China
| | - Xiaoyang Li
- Department of Environmental Health, School of Public Health, China Medical University, No.77 Puhe Road, Shenbei New District, Shenyang 110122, Liaoning China
| | - Yanfeng Wei
- Department of Environmental Health, School of Public Health, China Medical University, No.77 Puhe Road, Shenbei New District, Shenyang 110122, Liaoning China
| | - Linlin Ni
- Department of Environmental Health, School of Public Health, China Medical University, No.77 Puhe Road, Shenbei New District, Shenyang 110122, Liaoning China
| | - Bin Xu
- Department of Environmental Health, School of Public Health, China Medical University, No.77 Puhe Road, Shenbei New District, Shenyang 110122, Liaoning China
| | - Yu Deng
- Department of Environmental Health, School of Public Health, China Medical University, No.77 Puhe Road, Shenbei New District, Shenyang 110122, Liaoning China
| | - Tianyao Yang
- Department of Environmental Health, School of Public Health, China Medical University, No.77 Puhe Road, Shenbei New District, Shenyang 110122, Liaoning China
| | - Wei Liu
- Department of Environmental Health, School of Public Health, China Medical University, No.77 Puhe Road, Shenbei New District, Shenyang 110122, Liaoning China
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9
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Abu-Zeid EH, Khalifa BA, Elewa YHA, Arisha AH, Ismail TA, Hendam BM, Abdel-Hamid SE. Bee venom Apis mellifera lamarckii rescues blood brain barrier damage and neurobehavioral changes induced by methyl mercury via regulating tight junction proteins expression in rat cerebellum. Food Chem Toxicol 2021; 154:112309. [PMID: 34062221 DOI: 10.1016/j.fct.2021.112309] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2021] [Revised: 05/21/2021] [Accepted: 05/25/2021] [Indexed: 12/22/2022]
Abstract
The objective of the current study is to investigate the protective effect of Egyptian bee venom (BV) against methyl mercury chloride (MMC) induced blood-brain barrier (BBB) damage and neurobehavioral changes. Eighty male Sprague-Dawley rats were randomly grouped into 1st control (C), 2nd BV (0.5 mg/kg S/C for14 days), 3rd MMC (6.7 mg/kg orally/14 days), and 4th MMC + BV group. MMC exposure significantly altered rat cognitive behavior, auditory startle habituation, and swimming performance, increased the exploratory, grooming, and stereotypic behavior. MMC significantly impaired BBB integrity via induction of inflammation, oxidative stress, and down-regulation of tight junction proteins genes (TJPs) mRNA expression levels: Occludin (OCC), Claudins-5 (CLDN5), Zonula occludens-1 (ZO-1), while up-regulated the transforming growth factor-beta (TGF-β) mRNA expression levels. MMC revealed a significantly higher percentage of IgG positive area ratio, a higher index ratio of Iba1, Sox10, and ss-DNA, while index ratio of CD31, neurofilament, and pan neuron showed a significant reduction. Administration of BV significantly regulates the MMC altered behavioral responses, TJPs relative mRNA expression, and the immune-expression markers for specific neural cell types. It could be concluded for the first time that BV retains a promising in vivo protection against MMC-induced BBB dysfunction and neurobehavioral toxicity.
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Affiliation(s)
- Ehsan H Abu-Zeid
- Department of Forensic Medicine and Toxicology, Faculty of Veterinary Medicine, Zagazig University, 44511, Egypt.
| | - Bouthaina A Khalifa
- Department of Forensic Medicine and Toxicology, Faculty of Veterinary Medicine, Cairo University, Cairo, 12211, Egypt
| | - Yaser H A Elewa
- Department of Histology and Cytology, Faculty of Veterinary Medicine, Zagazig University, 44511, Egypt; Laboratory of Anatomy, Department of Basic Veterinary Sciences, Faculty of Veterinary Medicine, Hokkaido University, Sapporo, Japan.
| | - Ahmed H Arisha
- Department of Animal Physiology and Biochemistry, Faculty of Veterinary Medicine, Badr University in Cairo (BUC), Badr City, Cairo, Egypt; Department of Physiology, Faculty of Veterinary Medicine, Zagazig University, Zagazig, 44511, Egypt
| | - Tamer A Ismail
- Department of Clinical Laboratory Sciences, Turabah University College, Taif University, P.O. Box 11099, Taif, 21944, Saudi Arabia
| | - Basma M Hendam
- Department of Husbandry and Development of Animal Wealth, Faculty of Veterinary Medicine, Mansoura University, Mansoura, 35516, Egypt
| | - Shereen El Abdel-Hamid
- Department of Veterinary Public Health, Faculty of Veterinary Medicine, Zagazig University, Zagazig, 44511, Egypt
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Cheng H, Yang B, Ke T, Li S, Yang X, Aschner M, Chen P. Mechanisms of Metal-Induced Mitochondrial Dysfunction in Neurological Disorders. TOXICS 2021; 9:142. [PMID: 34204190 PMCID: PMC8235163 DOI: 10.3390/toxics9060142] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Revised: 06/12/2021] [Accepted: 06/14/2021] [Indexed: 01/31/2023]
Abstract
Metals are actively involved in multiple catalytic physiological activities. However, metal overload may result in neurotoxicity as it increases formation of reactive oxygen species (ROS) and elevates oxidative stress in the nervous system. Mitochondria are a key target of metal-induced toxicity, given their role in energy production. As the brain consumes a large amount of energy, mitochondrial dysfunction and the subsequent decrease in levels of ATP may significantly disrupt brain function, resulting in neuronal cell death and ensuing neurological disorders. Here, we address contemporary studies on metal-induced mitochondrial dysfunction and its impact on the nervous system.
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Affiliation(s)
- Hong Cheng
- Department of Occupational Health and Environmental Health, School of Public Health, Guangxi Medical University, Nanning 530021, China; (H.C.); (X.Y.)
| | - Bobo Yang
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY 10461, USA; (B.Y.); (T.K.)
| | - Tao Ke
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY 10461, USA; (B.Y.); (T.K.)
| | - Shaojun Li
- Department of Toxicology, School of Public Health, Guangxi Medical University, Nanning 530021, China;
| | - Xiaobo Yang
- Department of Occupational Health and Environmental Health, School of Public Health, Guangxi Medical University, Nanning 530021, China; (H.C.); (X.Y.)
- Department of Public Health, School of Medicine, Guangxi University of Science and Technology, Liuzhou 545006, China
| | - Michael Aschner
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY 10461, USA; (B.Y.); (T.K.)
| | - Pan Chen
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY 10461, USA; (B.Y.); (T.K.)
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Revisiting Astrocytic Roles in Methylmercury Intoxication. Mol Neurobiol 2021; 58:4293-4308. [PMID: 33990914 DOI: 10.1007/s12035-021-02420-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Accepted: 05/04/2021] [Indexed: 02/06/2023]
Abstract
Intoxication by heavy metals such as methylmercury (MeHg) is recognized as a global health problem, with strong implications in central nervous system pathologies. Most of these neuropathological conditions involve vascular, neurotransmitter recycling, and oxidative balance disruption leading to accelerated decline in fine balance, and learning, memory, and visual processes as main outcomes. Besides neurons, astrocytes are involved in virtually all the brain processes and perform important roles in neurological response following injuries. Due to astrocytes' strategic functions in brain homeostasis, these cells became the subject of several studies on MeHg intoxication. The most heterogenous glial cells, astrocytes, are composed of plenty of receptors and transporters to dialogue with neurons and other cells and to monitor extracellular environment responding tightly through fluctuation of cytosolic ions. The overall toxicity of MeHg might be determined on the basis of the balance between MeHg-mediated injury to neurons and protective responses from astrocytes. Although the role of neurons in MeHg intoxication is relatively well-established, the role of the astrocytes is only beginning to be understood. In this review, we update the information on astroglial modulation of the MeHg-induced neurotoxicity, providing remarks on their protective and deleterious roles and insights for future studies.
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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: 37] [Impact Index Per Article: 12.3] [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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Yang B, Zhao W, Yin C, Bai Y, Wang S, Xing G, Li F, Bian J, Aschner M, Cai J, Shi H, Lu R. Acute acrylonitrile exposure inhibits endogenous H 2S biosynthesis in rat brain and liver: The role of CBS/3-MPST-H 2S pathway in its astrocytic toxicity. Toxicology 2021; 451:152685. [PMID: 33486070 DOI: 10.1016/j.tox.2021.152685] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Revised: 12/12/2020] [Accepted: 01/15/2021] [Indexed: 12/11/2022]
Abstract
Hydrogen sulfide (H2S) as the third gasotransmitter molecule serves various biological regulatory roles in health and disease. Acrylonitrile (AN) is a common occupational toxicant and environmental pollutant, causing brain and liver damage in mammals. The biotransformation of AN is dependent-upon reduced glutathione (GSH), cysteine and other sulfur-containing compounds. However, the effects of AN on the endogenous H2S biosynthesis pathway have yet to be determined. Herein, we demonstrated that a single exposure to AN (at 25, 50, or 75 mg/kg for 1, 6 or 24 h) decreased the endogenous H2S content and H2S-producing capacity in a dose-dependent manner, both in the cerebral cortex and liver of rats in vivo. In addition, the inhibitory effects of AN (1, 2.5, 5, 10 mM for 12 h) on the H2S content and/or the expression of H2S-producing enzymes were also found both in primary rat astrocytes and rat liver cell line (BRL cells). Impairment in the H2S biosynthesis pathway was also assessed in primary rat astrocytes treated with AN. It was found that inhibition of the cystathionine-β-synthase (CBS)/3-mercaptopyruvate sulfurtransferase (3-MPST)-H2S pathway with the CBS inhibitor or 3-MPST-targeted siRNA significantly increased the AN-induced (5 mM for 12 h) cytotoxicity in astrocytes. In turn, CBS activation or 3-MPST overexpression as well as exogenous NaHS supplementation significantly attenuated AN-induced cytotoxicity. Taken together, endogenous H2S biosynthesis pathway was disrupted in rats acutely exposed to AN, which contributes to acute AN neurotoxicity in primary rat astrocytes.
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Affiliation(s)
- Bobo Yang
- Department of Preventive Medicine and Public Health Laboratory Science, School of Medicine, Jiangsu University, 301 Xuefu Road, Zhenjiang, Jiangsu, 212013, China
| | - Wenjun Zhao
- Department of Preventive Medicine and Public Health Laboratory Science, School of Medicine, Jiangsu University, 301 Xuefu Road, Zhenjiang, Jiangsu, 212013, China; Department of Clinical Laboratory, Affiliated People's Hospital to Jiangsu University School of Medicine, Zhenjiang, Jiangsu, 212002, China
| | - Changsheng Yin
- Department of Preventive Medicine and Public Health Laboratory Science, School of Medicine, Jiangsu University, 301 Xuefu Road, Zhenjiang, Jiangsu, 212013, China
| | - Yu Bai
- Department of Preventive Medicine and Public Health Laboratory Science, School of Medicine, Jiangsu University, 301 Xuefu Road, Zhenjiang, Jiangsu, 212013, China
| | - Suhua Wang
- Department of Preventive Medicine and Public Health Laboratory Science, School of Medicine, Jiangsu University, 301 Xuefu Road, Zhenjiang, Jiangsu, 212013, China
| | - Guangwei Xing
- Department of Preventive Medicine and Public Health Laboratory Science, School of Medicine, Jiangsu University, 301 Xuefu Road, Zhenjiang, Jiangsu, 212013, China
| | - Fang Li
- Department of Preventive Medicine and Public Health Laboratory Science, School of Medicine, Jiangsu University, 301 Xuefu Road, Zhenjiang, Jiangsu, 212013, China
| | - Jinsong Bian
- Department of Pharmacology, School of Medicine, National Singapore University, 117597, Singapore
| | - Michael Aschner
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY, 10461, USA
| | - Jiyang Cai
- Department of Physiology, College of Medicine, University of Oklahoma Health Science Center, Lindsay, Oklahoma City, OK, 73104, USA
| | - Haifeng Shi
- School of Life Sciences, Jiangsu University, Zhenjiang, Jiangsu, 212013, China
| | - Rongzhu Lu
- Department of Preventive Medicine and Public Health Laboratory Science, School of Medicine, Jiangsu University, 301 Xuefu Road, Zhenjiang, Jiangsu, 212013, China; Center for Experimental Research, Affiliated Kunshan Hospital to Jiangsu University School of Medicine, Kunshan, Suzhou, Jiangsu, 215132, China.
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14
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He L, Liu F, Zhao J, Liu Q, Cui L, Yu YL, Fan Y, Li B, Li YF. Temporal trends of urinary mercury in Chinese people from 1970s to 2010s: A review. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2021; 208:111460. [PMID: 33120263 DOI: 10.1016/j.ecoenv.2020.111460] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 09/29/2020] [Accepted: 10/02/2020] [Indexed: 06/11/2023]
Abstract
Mercury (Hg) is one of the most toxic heavy metals. It can migrate around the globe and magnify through the food chain, ultimately harming human health. Urinary Hg reflects recent exposure of Hg, which reflects the status of environmental contamination by Hg. This review summarized the levels and presented temporal trends of urinary Hg in Chinese people (both the general public and the occupationally exposed people) reported from 1970s to 2010s. It was found that urinary Hg levels in 92.3% of the reported population were less than the reference value (10.0 µg/L) recommended by Chinese health authority, while 76.9% were less than the reference value (4.0 µg/L) recommended by World Health Organization (WHO) in the general public in China. For the temporal trend from 1970s to 2010s, the urinary Hg levels in the general public in China were found to decrease gradually. In the occupationally exposed people, the urinary Hg levels generally exceeded the reference value (10.0 µg/L) for the general public, and about half of them were higher than the occupational exposure limit (35.0 µg/g creatinine) set by Chinese Occupational Health Standard (WS/T 265 - 2006). From 1970s to 2010s, the urinary Hg levels in occupationally exposed population increased first and then decreased slowly. Hg miners in Guizhou were found to have the highest urinary Hg levels, while workers in Anhui, Chongqing, Qinghai and Shanxi also had high levels of urinary Hg. In all, the urinary Hg levels in both the general public and the occupationally exposed people decreased from 1970s to 2010s, especially in recent decades. Attention should be paid to occupationally exposed people since high levels of urinary Hg were found in them. The message provided in this review can help better understand the situation of Hg burden in Chinese people and lay a basis for the coming effectiveness evaluation on the implementation of Minamata Convention on Mercury. Capsule abstract: The urinary Hg levels in both the general public and the occupationally exposed people in China are decreasing.
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Affiliation(s)
- Lina He
- Department of Chemistry, College of Sciences, Northeastern University, Shenyang 110819, Liaoning, China; CAS-HKU Joint Laboratory of Metallomics on Health and Environment, Beijing 100049, China; CAS Key Laboratory for Biological Effects of Nanomaterials and Nanosafety, Beijing 100049, China; Beijing Metallomics Facility, Beijing 100049, China; National Consortium for Excellence in Metallomics, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
| | - Fang Liu
- Rizhao Central Hospital, Rizhao 276800, Shandong, China
| | - Jiating Zhao
- CAS-HKU Joint Laboratory of Metallomics on Health and Environment, Beijing 100049, China; CAS Key Laboratory for Biological Effects of Nanomaterials and Nanosafety, Beijing 100049, China; Beijing Metallomics Facility, Beijing 100049, China; National Consortium for Excellence in Metallomics, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
| | - Quancheng Liu
- Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, Shandong Agricultural University, Taian 271018, Shandong, China
| | - Liwei Cui
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yong-Liang Yu
- Department of Chemistry, College of Sciences, Northeastern University, Shenyang 110819, Liaoning, China.
| | - Yuqin Fan
- Shandong Provincial Maternal & Child Health Care Hospital, Cheeloo College of Medicine, Shandong University, Jinan 250014, Shandong, China
| | - Bai Li
- CAS-HKU Joint Laboratory of Metallomics on Health and Environment, Beijing 100049, China; CAS Key Laboratory for Biological Effects of Nanomaterials and Nanosafety, Beijing 100049, China; Beijing Metallomics Facility, Beijing 100049, China; National Consortium for Excellence in Metallomics, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
| | - Yu-Feng Li
- CAS-HKU Joint Laboratory of Metallomics on Health and Environment, Beijing 100049, China; CAS Key Laboratory for Biological Effects of Nanomaterials and Nanosafety, Beijing 100049, China; Beijing Metallomics Facility, Beijing 100049, China; National Consortium for Excellence in Metallomics, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China.
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15
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Abstract
Ebselen is a synthetic organoselenium radical scavenger compound that possesses glutathione peroxidase-like activity and its own unique bioactivity by reacting with thiols, hydroperoxides and peroxynitrites. Owing to its high affinity toward several essential reactions, ebselen protects cellular components from oxidative and free radical damage, and it has been employed as a useful tool for studying redox-related mechanisms. Based on numerous in vitro and in vivo research, mechanisms are proposed to understand the biomedical and molecular actions of ebselen in health and disease, and it is currently under clinical trials for the prevention and treatment of various human disorders. Based on these outstanding discoveries, this review summarizes the current understanding of the biochemical and molecular characteristics, pharmacological applications and future directions of ebselen.
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Ahmad SF, Bakheet SA, Ansari MA, Nadeem A, Alobaidi AF, Attia SM, Alhamed AS, Aldossari AA, Mahmoud MA. Methylmercury chloride exposure aggravates proinflammatory mediators and Notch-1 signaling in CD14 + and CD40 + cells and is associated with imbalance of neuroimmune function in BTBR T + Itpr3tf/J mice. Neurotoxicology 2020; 82:9-17. [PMID: 33166615 DOI: 10.1016/j.neuro.2020.10.014] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 10/22/2020] [Accepted: 10/28/2020] [Indexed: 12/18/2022]
Abstract
Autism spectrum disorder (ASD) is a severe neurodevelopmental disorder characterized by deficits in social interaction, communication, and repetitive behaviors. A key role for immune dysfunction has been suggested in ASD. Recent studies have indicated that inflammatory mediators and Notch-1 signaling may contribute to the development of ASD. Methylmercury chloride (MeHgCl) is an environmental pollutant that primarily affects the central nervous system, causing neurological alterations. Its effects on immunological responses have not been fully investigated in ASD. In this study, we examined the influence of MeHgCl exposure on inflammatory mediators and Notch-1 signaling in BTBR T+ Itpr3tf/J (BTBR) mice, a model of ASD. We examined the effects of MeHgCl on the IL-6-, GM-CSF-, NF-κB p65-, Notch-1-, and IL-27-producing CD14+ and CD40+ cells in the spleen. We assessed the effect of MeHgCl on IL-6, GM-CSF, NF-κB p65, Notch-1, and IL-27 mRNA levels in brain tissue. We also measured IL-6, GM-CSF, and NF-κB p65 protein expression levels in brain tissue. MeHgCl exposure of BTBR mice significantly increased IL-6-, GM-CSF-, NF-κB p65-, and Notch-1-, and decreased IL-27-producing CD14+, and CD40+ cells in the spleen. MeHgCl exposure of BTBR mice upregulated IL-6, GM-CSF, NF-κB p65, and Notch-1, and decreased IL-27 mRNA expression levels in brain tissue. Moreover, MeHgCl resulted in elevated expression of the IL-6, GM-CSF, and NF-κB p65 proteins in brain tissue. Taken together, these results indicate that MeHgCl exposure aggravates proinflammatory mediators and Notch-1 signaling which are associated with imbalance of neuroimmune function in BTBR mice.
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Affiliation(s)
- Sheikh F Ahmad
- Department of Pharmacology and Toxicology, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia.
| | - Saleh A Bakheet
- Department of Pharmacology and Toxicology, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
| | - Mushtaq A Ansari
- Department of Pharmacology and Toxicology, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
| | - Ahmed Nadeem
- Department of Pharmacology and Toxicology, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
| | - Abdulelah F Alobaidi
- Department of Pharmacology and Toxicology, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
| | - Sabry M Attia
- Department of Pharmacology and Toxicology, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
| | - Abdullah S Alhamed
- Department of Pharmacology and Toxicology, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
| | - Abdullah A Aldossari
- Department of Pharmacology and Toxicology, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
| | - Mohamed A Mahmoud
- Department of Pharmacology and Toxicology, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
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Jin X, Chen D, Wu F, Zhang L, Huang Y, Lin Z, Wang X, Wang R, Xu L, Chen Y. Hydrogen Sulfide Protects Against Ammonia-Induced Neurotoxicity Through Activation of Nrf2/ARE Signaling in Astrocytic Model of Hepatic Encephalopathy. Front Cell Neurosci 2020; 14:573422. [PMID: 33192318 PMCID: PMC7642620 DOI: 10.3389/fncel.2020.573422] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Accepted: 09/15/2020] [Indexed: 12/13/2022] Open
Abstract
Objective: Hepatic encephalopathy (HE) characterized by neuropsychiatric abnormalities is a major complication of cirrhosis with high mortality. However, the pathogenesis of HE has not been fully elucidated. This study aimed to determine endogenous hydrogen sulfide (H2S) in the blood of HE patients and investigate the role of H2S in an astrocytic model of HE. Methods: Patients with and without HE were recruited to determine plasma H2S levels and blood microbial 16S rRNA gene. Rat astrocytes were employed as a model of HE by treatment of NH4Cl. Exogenous H2S was preadded. Cell viability was measured by Cell Counting Kit-8 (CCK-8) assay, and cell death was evaluated by lactate dehydrogenase (LDH) release. Apoptosis was determined by Hoechst 33342/Propidium Iodide (PI) Double Staining and Western blot analysis of apoptosis-related protein expression. Intracellular reactive oxygen species (ROS) levels were assessed by flow cytometer. Expressions of Nrf2 and its downstream regulated genes were examined by immunofluorescence staining and Western blot, respectively. Nrf2 gene knockdown was performed by antisense shRNA of Nrf2 gene. Results: There was a significant decrease in H2S levels in cirrhotic patients with HE compared with without HE. Blood microbiota analyses revealed that certain strains associated with H2S production were negatively correlated with HE. In vitro, H2S markedly attenuated NH4Cl-induced cytotoxicity, oxidative stress, and apoptosis. This effect was mediated by Nrf2/ARE signaling, and knockdown of Nrf2 expression abolished the antagonistic effect of H2S on NH4Cl-induced neurotoxicity in astrocytes. Conclusion: Levels of H2S and bacteria associated with H2S production are decreased in HE, and H2S functions as the neuroprotector against NH4Cl-induced HE by activating Nrf2/ARE signaling of astrocytes.
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Affiliation(s)
- Xiaozhi Jin
- Department of Infectious Diseases, Wenzhou Key Laboratory of Hepatology, The First Affiliated Hospital of Wenzhou Medical University, Hepatology Institute of Wenzhou Medical University, Zhejiang Provincial Key Laboratory for Accurate Diagnosis and Treatment of Chronic Liver Diseases, Wenzhou, China
| | - Dazhi Chen
- Department of Gastroenterology, The First Hospital of Peking University, Beijing, China
| | - Faling Wu
- Department of Infectious Diseases, Wenzhou Key Laboratory of Hepatology, The First Affiliated Hospital of Wenzhou Medical University, Hepatology Institute of Wenzhou Medical University, Zhejiang Provincial Key Laboratory for Accurate Diagnosis and Treatment of Chronic Liver Diseases, Wenzhou, China
| | - Lei Zhang
- Department of Infectious Diseases, Wenzhou Key Laboratory of Hepatology, The First Affiliated Hospital of Wenzhou Medical University, Hepatology Institute of Wenzhou Medical University, Zhejiang Provincial Key Laboratory for Accurate Diagnosis and Treatment of Chronic Liver Diseases, Wenzhou, China
| | - Yu Huang
- Department of Infectious Diseases, Wenzhou Key Laboratory of Hepatology, The First Affiliated Hospital of Wenzhou Medical University, Hepatology Institute of Wenzhou Medical University, Zhejiang Provincial Key Laboratory for Accurate Diagnosis and Treatment of Chronic Liver Diseases, Wenzhou, China
| | - Zhuo Lin
- Department of Infectious Diseases, Wenzhou Key Laboratory of Hepatology, The First Affiliated Hospital of Wenzhou Medical University, Hepatology Institute of Wenzhou Medical University, Zhejiang Provincial Key Laboratory for Accurate Diagnosis and Treatment of Chronic Liver Diseases, Wenzhou, China
| | - Xiaodong Wang
- Department of Infectious Diseases, Wenzhou Key Laboratory of Hepatology, The First Affiliated Hospital of Wenzhou Medical University, Hepatology Institute of Wenzhou Medical University, Zhejiang Provincial Key Laboratory for Accurate Diagnosis and Treatment of Chronic Liver Diseases, Wenzhou, China
| | - Rui Wang
- Department of Infectious Diseases, Wenzhou Key Laboratory of Hepatology, The First Affiliated Hospital of Wenzhou Medical University, Hepatology Institute of Wenzhou Medical University, Zhejiang Provincial Key Laboratory for Accurate Diagnosis and Treatment of Chronic Liver Diseases, Wenzhou, China
| | - Lanman Xu
- Department of Infectious Diseases and Liver Diseases, Ningbo Medical Center Lihuili Hospital, Ningbo, China.,Department of Infectious Diseases and Liver Diseases, The Affiliated Lihuili Hospital of Ningbo University, Ningbo, China
| | - Yongping Chen
- Department of Infectious Diseases, Wenzhou Key Laboratory of Hepatology, The First Affiliated Hospital of Wenzhou Medical University, Hepatology Institute of Wenzhou Medical University, Zhejiang Provincial Key Laboratory for Accurate Diagnosis and Treatment of Chronic Liver Diseases, Wenzhou, China
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18
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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: 19] [Impact Index Per Article: 4.8] [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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19
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Cephalic Neuronal Vesicle Formation is Developmentally Dependent and Modified by Methylmercury and sti-1 in Caenorhabditis elegans. Neurochem Res 2020; 45:2939-2948. [PMID: 33037975 DOI: 10.1007/s11064-020-03142-8] [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: 07/20/2020] [Revised: 09/26/2020] [Accepted: 10/01/2020] [Indexed: 01/09/2023]
Abstract
Methylmercury (MeHg) is a potent neurotoxicant. The mechanisms underlying MeHg-induced neurotoxicity are not fully understood. Several studies have shown that protein chaperones are involved in MeHg toxicity. The protein co-chaperone, stress inducible protein 1 (STI-1), has important functions in protein quality control of the chaperone pathway. In the current study, dopaminergic (DAergic) cephalic (CEP) neuronal morphology was evaluated in the Caenorhabditis elegans (C. elegans) sti-1 knockout strain. In the control OH7193 strain (dat-1::mCherry + ttx-3::mCherry), we characterized the morphology of CEP neurons by checking the presence of attached vesicles and unattached vesicles to the CEP dendrites. We showed that the attached vesicles were only present in adult stage worms; whereas they were absent in the younger L3 stage worms. In the sti-1 knockout strain, MeHg treatment significantly altered the structures of CEP dendrites with discontinuation of mCherry fluorescence and shrinkage of CEP soma, as compared to the control. 12 h post treatment on MeHg-free OP50-seeded plates, the discontinuation of mCherry fluorescence of CEP dendrites in worms treated with 0.05 or 0.5 µM MeHg returned to levels statistically indistinguishable from control, while in worms treated with 5 µM MeHg a higher percentage of discontinuation of mCherry fluorescence persisted. Despite this strong effect by 5 µM MeHg, CEP attached vesicles were increased upon 0.05 or 0.5 µM MeHg treatment, yet unaffected by 5 µM MeHg. The CEP attached vesicles of sti-1 knockout strain were significantly increased shortly after MeHg treatment, but were unaffected 48 h post treatment. In addition, there was a significant interactive effect of MeHg and sti-1 on the number of attached vesicles. Knock down sti-1 via RNAi did not alter the number of CEP attached vesicles. Taking together, our data suggests that the increased occurrence of attached vesicles in adult stage worms could initiate a substantial loss of membrane components of CEP dendrites following release of vesicles, leading to the discontinuation of mCherry fluorescence, and the formation of CEP attached vesicles could be regulated by sti-1 to remove cellular debris for detoxification.
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Pérez CA, Shah EG, Butler IJ. Mercury-induced autoimmunity: Report of two adolescent siblings with Morvan syndrome "plus" and review of the literature. J Neuroimmunol 2020; 342:577197. [PMID: 32126315 DOI: 10.1016/j.jneuroim.2020.577197] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2019] [Revised: 02/08/2020] [Accepted: 02/21/2020] [Indexed: 02/06/2023]
Abstract
Heavy metal toxicity is a global health concern. Mercury intoxication has been implicated in the etiology and pathogenesis of autoimmune disease, including Morvan syndrome. We describe two siblings with overlapping features of distinct autoimmune syndromes following accidental exposure to elemental mercury. Morvan syndrome was the predominant clinical phenotype. In addition to the characteristic anti-leucine-rich glioma-inactivated protein 1 (LGI1) and anti-contactin-associated protein-like 2 (Caspr2) autoantibodies, glutamic acid decarboxylase 65-kilodalton isoform (GAD65), and N-type and P/Q-type voltage-gated calcium channel (VGCC) antibodies were detected. Treatment with chelation therapy, glucocorticoids, and intravenous immunoglobulin was unsuccessful, but complete resolution of symptoms was achieved following treatment with rituximab. Herein, we perform an extensive review of the literature with a focus on the emerging concepts of mercury-induced autoimmunity and the role of mercury in the etiopathogenesis of autoimmune diseases of the nervous system.
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Affiliation(s)
- Carlos A Pérez
- Division of Multiple Sclerosis and Neuroimmunology, Department of Neurology, University of Texas Health Science Center at Houston, Houston, TX, USA.
| | - Ekta G Shah
- Division of Child and Adolescent Neurology, Department of Pediatrics, University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Ian J Butler
- Division of Child and Adolescent Neurology, Department of Pediatrics, University of Texas Health Science Center at Houston, Houston, TX, USA
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Chang J, Yang B, Zhou Y, Yin C, Liu T, Qian H, Xing G, Wang S, Li F, Zhang Y, Chen D, Aschner M, Lu R. Acute Methylmercury Exposure and the Hypoxia-Inducible Factor-1α Signaling Pathway under Normoxic Conditions in the Rat Brain and Astrocytes in Vitro. ENVIRONMENTAL HEALTH PERSPECTIVES 2019; 127:127006. [PMID: 31850806 PMCID: PMC6957278 DOI: 10.1289/ehp5139] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/10/2019] [Revised: 11/07/2019] [Accepted: 11/18/2019] [Indexed: 06/10/2023]
Abstract
BACKGROUND As a ubiquitous environmental pollutant, methylmercury (MeHg) induces toxic effects in the nervous system, one of its main targets. However, the exact mechanisms of its neurotoxicity have not been fully elucidated. Hypoxia-inducible factor- 1 α (HIF- 1 α ), a transcription factor, plays a crucial role in adaptive and cytoprotective responses in cells and is involved in cell survival, proliferation, apoptosis, inflammation, angiogenesis, glucose metabolism, erythropoiesis, and other physiological activities. OBJECTIVES The aim of this study was to explore the role of HIF- 1 α in response to acute MeHg exposure in rat brain and primary cultured astrocytes to improve understanding of the mechanisms of MeHg-induced neurotoxicity and the development of effective neuroprotective strategies. METHODS Primary rat astrocytes were treated with MeHg (0 - 10 μ M ) for 0.5 h . Cell proliferation and cytotoxicity were assessed with a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl diphenyltetrazolium bromide (MTT) assay and a lactate dehydrogenase (LDH) release assay, respectively. Reactive oxygen species (ROS) levels were analyzed to assess the level of oxidative stress using 2',7'-dichlorofluorescin diacetate (DCFH-DA) fluorescence. HIF- 1 α , and its downstream proteins, glucose transporter 1 (GLUT-1), erythropoietin (EPO), and vascular endothelial growth factor A (VEGF-A) were analyzed by means of Western blotting. Real-time PCR was used to detect the expression of HIF- 1 α mRNA. Pretreatment with protein synthesis inhibitor (CHX), proteasome inhibitor (MG132), or proline hydroxylase inhibitor (DHB) were applied to explore the possible mechanisms of HIF- 1 α inhibition by MeHg. To investigate the role of HIF- 1 α in MeHg-induced neurotoxicity, cobalt chloride (CoC l 2 ), 2-methoxyestradiol (2-MeOE2), small interfering RNA (siRNA) transfection and adenovirus overexpression were used. Pretreatment with N-acetyl-L-cysteine (NAC) and vitamin E (Trolox) were used to investigate the putative role of oxidative stress in MeHg-induced alterations in HIF- 1 α levels. The expression of HIF- 1 α and related downstream proteins was detected in adult rat brain exposed to MeHg (0 - 10 mg / kg ) for 0.5 h in vivo. RESULTS MeHg caused lower cell proliferation and higher cytotoxicity in primary rat astrocytes in a time- and concentration-dependent manner. In comparison with the control cells, exposure to 10 μ M MeHg for 0.5 h significantly inhibited the expression of astrocytic HIF- 1 α , and the downstream genes GLUT-1, EPO, and VEGF-A (p < 0.05 ), in the absence of a significant decrease in HIF- 1 α mRNA levels. When protein synthesis was inhibited by CHX, MeHg promoted the degradation rate of HIF- 1 α . MG132 and DHB significantly blocked the MeHg-induced decrease in HIF- 1 α expression (p < 0.05 ). Overexpression of HIF- 1 α significantly attenuated the decline in MeHg-induced cell proliferation, whereas the inhibition of HIF- 1 α significantly increased the decline in cell proliferation (p < 0.05 ). NAC and Trolox, two established antioxidants, reversed the MeHg-induced decline in HIF- 1 α protein levels and the decrease in cell proliferation (p < 0.05 ). MeHg suppressed the expression of HIF- 1 α and related downstream target proteins in adult rat brain. DISCUSSION MeHg induced a significant reduction in HIF- 1 α protein by activating proline hydroxylase (PHD) and the ubiquitin proteasome system (UPS) in primary rat astrocytes. Additionally, ROS scavenging by antioxidants played a neuroprotective role via increasing HIF- 1 α expression in response to MeHg toxicity. Moreover, we established that up-regulation of HIF- 1 α might serve to mitigate the acute toxicity of MeHg in astrocytes, affording a novel therapeutic target for future exploration. https://doi.org/10.1289/EHP5139.
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Affiliation(s)
- Jie Chang
- Department of Preventive Medicine and Public Health Laboratory Sciences, School of Medicine, Jiangsu University, Zhenjiang, China
| | - Bobo Yang
- Department of Preventive Medicine and Public Health Laboratory Sciences, School of Medicine, Jiangsu University, Zhenjiang, China
| | - Yun Zhou
- Department of Preventive Medicine and Public Health Laboratory Sciences, School of Medicine, Jiangsu University, Zhenjiang, China
| | - Changsheng Yin
- Department of Preventive Medicine and Public Health Laboratory Sciences, School of Medicine, Jiangsu University, Zhenjiang, China
- Institute of Life Sciences, Jiangsu University, Zhenjiang, China
| | - Tingting Liu
- Department of Preventive Medicine and Public Health Laboratory Sciences, School of Medicine, Jiangsu University, Zhenjiang, China
| | - Hai Qian
- Department of Preventive Medicine and Public Health Laboratory Sciences, School of Medicine, Jiangsu University, Zhenjiang, China
| | - Guangwei Xing
- Department of Preventive Medicine and Public Health Laboratory Sciences, School of Medicine, Jiangsu University, Zhenjiang, China
| | - Suhua Wang
- Department of Preventive Medicine and Public Health Laboratory Sciences, School of Medicine, Jiangsu University, Zhenjiang, China
| | - Fang Li
- Department of Preventive Medicine and Public Health Laboratory Sciences, School of Medicine, Jiangsu University, Zhenjiang, China
| | - Yubin Zhang
- Department of Occupational Health and Toxicology, School of Public Health, Fudan University, Shanghai, China
| | - Da Chen
- School of Environment, Guangdong Key Laboratory of Environmental Pollution and Health, Jinan University, Guangzhou, China
| | - Michael Aschner
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Rongzhu Lu
- Department of Preventive Medicine and Public Health Laboratory Sciences, School of Medicine, Jiangsu University, Zhenjiang, China
- Center for Experimental Research, Kunshan Hospital Affiliated to Jiangsu University, Kunshan, China
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Nobre P, Cabral MDF, Costa J, Castro-Caldas M, Carvalho C, Branco V. In Vitro Assessment of the Efficacy of a Macrocyclic Chelator in Reversing Methylmercury Toxicity. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2019; 16:ijerph16234817. [PMID: 31801208 PMCID: PMC6926914 DOI: 10.3390/ijerph16234817] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 11/22/2019] [Accepted: 11/28/2019] [Indexed: 12/25/2022]
Abstract
Methylmercury (MeHg) is a highly neurotoxic compound to which human populations are exposed via fish consumption. Once in cells, MeHg actively binds thiols and selenols, interfering with the activity of redox enzymes such as thioredoxin (Trx) and the selenoenzyme thioredoxin reductase (TrxR) which integrate the thioredoxin system. In fact, it has been shown that inhibition of this system by MeHg is a critical step in the unfolding of cell death. Current clinical approaches to mitigate the toxicity of MeHg rely on the use of chelators, such as meso-2,3-dimercaptosuccinic acid (DMSA) which largely replaced British anti-Lewisite or 2,3-dimercapto-1-propanol (BAL) as the prime choice. However, therapeutic efficacy is limited and therefore new therapeutic options are necessary. In this work, we evaluated the efficacy of a macrocyclic chelator, 1-thia-4,7,10,13-tetraazacyclopentadecane ([15]aneN4S), in preventing MeHg toxicity, namely by looking at the effects over relevant molecular targets, i.e., the thioredoxin system, using both purified enzyme solutions and cell experiments with human neuroblastoma cells (SH-SY5Y). Results showed that [15]aneN4S had a similar efficacy to DMSA and BAL in reversing the inhibition of MeHg over purified TrxR and Trx by looking at both the 5,5′-dithiobis(2-nitrobenzoic acid) (DTNB) reduction assay and insulin reduction capability. In experiments with cells, none of the chelating agents could reverse the inhibition of TrxR by MeHg, which corroborates the high affinity of MeHg to the selenol in TrxR active site. [15]aneN4S and BAL, unlike DMSA, could prevent inhibition of Trx, which allows the maintenance of downstream functions, although BAL showed higher toxicity to cells. Overall these findings highlight the potential of using [15]aneN4S in the treatment of MeHg poisoning and encourage further studies, namely in vivo.
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Affiliation(s)
- Paula Nobre
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal; (P.N.); (M.d.F.C.); (J.C.); (M.C.-C.); (C.C.)
| | - Maria de Fátima Cabral
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal; (P.N.); (M.d.F.C.); (J.C.); (M.C.-C.); (C.C.)
| | - Judite Costa
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal; (P.N.); (M.d.F.C.); (J.C.); (M.C.-C.); (C.C.)
| | - Margarida Castro-Caldas
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal; (P.N.); (M.d.F.C.); (J.C.); (M.C.-C.); (C.C.)
- UCIBIO, Departamento Ciências da Vida, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa, 2829-516 Caparica, Portugal
| | - Cristina Carvalho
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal; (P.N.); (M.d.F.C.); (J.C.); (M.C.-C.); (C.C.)
| | - Vasco Branco
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal; (P.N.); (M.d.F.C.); (J.C.); (M.C.-C.); (C.C.)
- Correspondence: ; Tel.:+351-217-946-400
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Yang B, Yin C, Zhou Y, Wang Q, Jiang Y, Bai Y, Qian H, Xing G, Wang S, Li F, Feng Y, Zhang Y, Cai J, Aschner M, Lu R. Curcumin protects against methylmercury-induced cytotoxicity in primary rat astrocytes by activating the Nrf2/ARE pathway independently of PKCδ. Toxicology 2019; 425:152248. [PMID: 31330227 PMCID: PMC6710134 DOI: 10.1016/j.tox.2019.152248] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Revised: 07/07/2019] [Accepted: 07/18/2019] [Indexed: 12/11/2022]
Abstract
Methylmercury (MeHg) is a ubiquitous environmental toxicant that leads to long-lasting neurological deficits in animals and humans. Curcumin, a polyphenol obtained from the rhizome of turmeric, has well-known antioxidant functions. Here, we evaluated curcumin's efficacy in mitigating MeHg-induced cytotoxicity and further investigated the underlying mechanism of this neuroprotection in primary rat astrocytes. Pretreatment with curcumin (2, 5, 10 and 20 μM for 3, 6, 12 or 24 h) protected against MeHg-induced (5 μM for 6 h) cell death in a time and dose-dependent manner. Curcumin (2, 5, 10 or 20 μM) pretreatment for 12 h significantly ameliorated the MeHg-induced astrocyte injury and oxidative stress, as evidenced by morphological alterations, lactate dehydrogenase (LDH) release, reactive oxygen species (ROS) generation, and glutathione (GSH) and catalase (CAT) levels. Moreover, curcumin pretreatment increased Nrf2 nuclear translocation and downstream enzyme expression, heme oxygenase-1 (HO-1) and NADPH quinone reductase-1 (NQO1). Knockdown of Nrf2 with siRNA attenuated the protective effect of curcumin against MeHg-induced cell death. However, both the pan-protein kinase C (PKC) inhibitor, Ro 31-8220, and the selective PKCδ inhibitor, rottlerin, failed to suppress the curcumin-activated Nrf2/Antioxidant Response Element(ARE) pathway and attenuate the protection exerted by curcumin. Taken together, these findings confirm that curcumin protects against MeHg-induced neurotoxicity by activating the Nrf2/ARE pathway and this protection is independent of PKCδ activation. More studies are needed to understand the mechanisms of curcumin cytoprotection.
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Affiliation(s)
- Bobo Yang
- Department of Preventive Medicine and Public Health Laboratory Sciences, School of Medicine, Jiangsu University, Zhenjiang, Jiangsu 212013, China
| | - Changsheng Yin
- Department of Preventive Medicine and Public Health Laboratory Sciences, School of Medicine, Jiangsu University, Zhenjiang, Jiangsu 212013, China; Institute of Life Sciences, Jiangsu University, Zhenjiang, Jiangsu 212013, China
| | - Yun Zhou
- Department of Preventive Medicine and Public Health Laboratory Sciences, School of Medicine, Jiangsu University, Zhenjiang, Jiangsu 212013, China
| | - Qiang Wang
- Department of Preventive Medicine and Public Health Laboratory Sciences, School of Medicine, Jiangsu University, Zhenjiang, Jiangsu 212013, China
| | - Yuanyue Jiang
- Department of Preventive Medicine and Public Health Laboratory Sciences, School of Medicine, Jiangsu University, Zhenjiang, Jiangsu 212013, China
| | - Yu Bai
- Department of Preventive Medicine and Public Health Laboratory Sciences, School of Medicine, Jiangsu University, Zhenjiang, Jiangsu 212013, China
| | - Hai Qian
- Department of Preventive Medicine and Public Health Laboratory Sciences, School of Medicine, Jiangsu University, Zhenjiang, Jiangsu 212013, China
| | - Guangwei Xing
- Department of Preventive Medicine and Public Health Laboratory Sciences, School of Medicine, Jiangsu University, Zhenjiang, Jiangsu 212013, China
| | - Suhua Wang
- Department of Preventive Medicine and Public Health Laboratory Sciences, School of Medicine, Jiangsu University, Zhenjiang, Jiangsu 212013, China
| | - Fang Li
- Department of Preventive Medicine and Public Health Laboratory Sciences, School of Medicine, Jiangsu University, Zhenjiang, Jiangsu 212013, China
| | - Yun Feng
- Department of Pharmacology, School of Medicine, Jiangsu University, Zhenjiang, Jiangsu 212013, China
| | - Yubin Zhang
- Department of Occupational Health and Toxicology, School of Public Health, Fudan University, Shanghai 200032, China
| | - Jiyang Cai
- Department of Ophthalmology and Visual Sciences, University of Texas Medical Branch, Galveston, TX 77550-1106, USA
| | - Michael Aschner
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Rongzhu Lu
- Department of Preventive Medicine and Public Health Laboratory Sciences, School of Medicine, Jiangsu University, Zhenjiang, Jiangsu 212013, China; Center for Experimental Research, Kunshan Hospital Affiliated to Jiangsu University, Kunshan, Jiangsu 215132, China.
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Takahashi T, Shimohata T. Vascular Dysfunction Induced by Mercury Exposure. Int J Mol Sci 2019; 20:E2435. [PMID: 31100949 PMCID: PMC6566353 DOI: 10.3390/ijms20102435] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Revised: 05/10/2019] [Accepted: 05/16/2019] [Indexed: 12/15/2022] Open
Abstract
Methylmercury (MeHg) causes severe damage to the central nervous system, and there is increasing evidence of the association between MeHg exposure and vascular dysfunction, hemorrhage, and edema in the brain, but not in other organs of patients with acute MeHg intoxication. These observations suggest that MeHg possibly causes blood-brain barrier (BBB) damage. MeHg penetrates the BBB into the brain parenchyma via active transport systems, mainly the l-type amino acid transporter 1, on endothelial cell membranes. Recently, exposure to mercury has significantly increased. Numerous reports suggest that long-term low-level MeHg exposure can impair endothelial function and increase the risks of cardiovascular disease. The most widely reported mechanism of MeHg toxicity is oxidative stress and related pathways, such as neuroinflammation. BBB dysfunction has been suggested by both in vitro and in vivo models of MeHg intoxication. Therapy targeted at both maintaining the BBB and suppressing oxidative stress may represent a promising therapeutic strategy for MeHg intoxication. This paper reviews studies on the relationship between MeHg exposure and vascular dysfunction, with a special emphasis on the BBB.
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Affiliation(s)
- Tetsuya Takahashi
- Department of Neurology, National Hospital Organization Nishiniigata Chuo Hospital, Niigata 950-2085, Japan.
| | - Takayoshi Shimohata
- Department of Neurology, Gifu University Graduate School of Medicine, Gifu 501-1194, Japan.
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Chalana A, Karri R, Das R, Kumar B, Rai RK, Saxena H, Gupta A, Banerjee M, Jha KK, Roy G. Copper-Driven Deselenization: A Strategy for Selective Conversion of Copper Ion to Nanozyme and Its Implication for Copper-Related Disorders. ACS APPLIED MATERIALS & INTERFACES 2019; 11:4766-4776. [PMID: 30644707 DOI: 10.1021/acsami.8b16786] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Synthetic organic molecules, which can selectively convert excess intracellular copper (Cu) ions to nanozymes with an ability to protect cells from oxidative stress, are highly significant in developing therapeutic agents against Cu-related disorder like Wilson's disease. Here, we report 1,3-bis(2-hydroxyethyl)-1 H-benzoimidazole-2-selenone (1), which shows a remarkable ability to remove Cu ion from glutathione, a major cytosolic Cu-binding ligand, and thereafter converts it into copper selenide (CuSe) nanozyme that exhibits remarkable glutathione peroxidase-like activity, at cellular level of H2O2 concentration, with excellent cytoprotective effect against oxidative stress in hepatocyte. Cu-driven deselenization of 1, under physiologically relevant conditions, occurred in two steps. The activation of C═Se bond by metal ion is the crucial first step, followed by cleavage of the metal-activated C═Se bond, initiated by the OH group of N-(CH2)2OH substituent through neighboring group participation (deselenization step), resulted in the controlled synthesis of various types of Cu2-xSe nanocrystals (NCs) (nanodisks, nanocubes, and nanosheets) and tetragonal Cu3Se2 NCs, depending upon the oxidation state of the Cu ion used to activate the C═Se bond. Deselenization of 1 is highly metal-selective. Except Cu, other essential metal ions, including Mn2+, Fe2+, Co2+, Ni2+, or Zn2+, failed to produce metal selenide under identical reaction conditions. Moreover, no significant change in the expression level of Cu-metabolism-related genes, including metallothioneines MT1A, is observed in liver cells co-treated with Cu and 1, as opposed to the large increase in the concentrations of these genes observed in cells treated with Cu alone, suggesting the participation of 1 in Cu homeostasis in hepatocyte.
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Ismail HTH. Hematobiochemical Disturbances and Oxidative Stress After Subacute Manganese Chloride Exposure and Potential Protective Effects of Ebselen in Rats. Biol Trace Elem Res 2019; 187:452-463. [PMID: 29858966 DOI: 10.1007/s12011-018-1395-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Accepted: 05/23/2018] [Indexed: 12/29/2022]
Abstract
The present study aimed to detect the possible disturbances induced by subacute exposure to manganese chloride (MnCl2) on some biomarkers of hematology, clinical chemistry and oxidative stress, serum iron homeostasis, and ferritin status beside the histopathological alterations in hepatic and renal tissues, and the potential protective effects of ebselen on the Mn toxicity were also evaluated. Forty-eight rats were divided into four groups: Group 1 was used as a control. Groups 2, 3, and 4 were administered of ebselen as a single protective dose (15 mg/kg BW) intraperitoneal, daily manganese chloride (50 mg/kg BW) orally, and ebselen plus manganese chloride, respectively. The administrations were conducted for 30 days. Blood and tissue samples were collected at the end of the treatment for various experimental tests. Results revealed that MnCl2 did not significantly change in erythrogram with leukocytosis and neutrophilia but significantly increased serum aminotransferases and alkaline phosphatase activities, bilirubin (total, direct, and indirect), globulins, triglycerides, total cholesterol, creatinine, urea, manganese, iron and ferritin concentrations and hepatic glutathione, renal malondialdehyde and nitric oxide levels and hepatic superoxide dismutase activity, while serum albumin, hepatic malondialdehyde, and nitric oxide concentrations were significantly decreased besides non-statistical change in serum total proteins concentration. Ebselen has reduced the disturbances in these analytes in combined treatment group. Collectively, subacute exposure to MnCl2 causes disturbance in the leukogram, and hepatic and renal functions with marked renal oxidative stress. It also disturbed serum iron homeostasis and ferritin status. Remarkably, ebselen appears to be highly effective in attenuating the various adverse effects of manganese.
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Affiliation(s)
- Hager Tarek H Ismail
- Department of Clinical Pathology, Faculty of Veterinary Medicine, Zagazig University, 1 Alzeraa Street, Zagazig, Sharkia Province, 44511, Egypt.
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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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28
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Ke T, Gonçalves FM, Gonçalves CL, Dos Santos AA, Rocha JBT, Farina M, Skalny A, Tsatsakis A, Bowman AB, Aschner M. Post-translational modifications in MeHg-induced neurotoxicity. Biochim Biophys Acta Mol Basis Dis 2018; 1865:2068-2081. [PMID: 30385410 DOI: 10.1016/j.bbadis.2018.10.024] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Revised: 10/16/2018] [Accepted: 10/19/2018] [Indexed: 12/29/2022]
Abstract
Mercury (Hg) exposure remains a major public health concern due to its widespread distribution in the environment. Organic mercurials, such as MeHg, have been extensively investigated especially because of their congenital effects. In this context, studies on the molecular mechanism of MeHg-induced neurotoxicity are pivotal to the understanding of its toxic effects and the development of preventive measures. Post-translational modifications (PTMs) of proteins, such as phosphorylation, ubiquitination, and acetylation are essential for the proper function of proteins and play important roles in the regulation of cellular homeostasis. The rapid and transient nature of many PTMs allows efficient signal transduction in response to stress. This review summarizes the current knowledge of PTMs in MeHg-induced neurotoxicity, including the most commonly PTMs, as well as PTMs induced by oxidative stress and PTMs of antioxidant proteins. Though PTMs represent an important molecular mechanism for maintaining cellular homeostasis and are involved in the neurotoxic effects of MeHg, we are far from understanding the complete picture on their role, and further research is warranted to increase our knowledge of PTMs in MeHg-induced neurotoxicity.
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Affiliation(s)
- Tao Ke
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY 10461, United States.
| | - Filipe Marques Gonçalves
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY 10461, United States
| | - Cinara Ludvig Gonçalves
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY 10461, United States
| | | | - João B T Rocha
- Departamento de Bioquímica e Biologia Molecular, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, 97105900 Santa Maria, RS, Brazil
| | - Marcelo Farina
- Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, 88040900 Florianópolis, SC, Brazil
| | - 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
| | - Aristidis Tsatsakis
- Center of Toxicology Science & Research, Medical School, University of Crete, Heraklion, Crete, Greece
| | - Aaron B Bowman
- School of Health Sciences, Purdue University, West Lafayette, IN, United States.
| | - Michael Aschner
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY 10461, United States.
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Consolidating probiotic with dandelion, coriander and date palm seeds extracts against mercury neurotoxicity and for maintaining normal testosterone levels in male rats. Toxicol Rep 2018; 5:1069-1077. [PMID: 30425928 PMCID: PMC6224333 DOI: 10.1016/j.toxrep.2018.10.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Revised: 10/19/2018] [Accepted: 10/20/2018] [Indexed: 11/22/2022] Open
Abstract
Objective Heavy metals are major elements polluting our universe. The inhalation, ingestion or even contacting human body with these elements results in huge health problems. The most common pollutant in our surrounding is mercury. Therefore, the present study aimed to elucidating the protective ability of hot water extracts of dandelion (DA), coriander (CO), date palm seeds (DS), probiotic supernatant (PS) and their combined mixture against mercury-induced neurotoxicity and altered testosterone levels in male rats. Methods Fifty six male rats were randomly allotted into seven groups (n = 8 rats/group). Group1 (negative control; NC) animals were fed on the basal diet only, group2 (positive controls; PC) animals were fed on the basal diet and given an aqueous solution of mercuric chloride (25 ppm mercuric) in drinking water. Animals of the antioxidant-treated groups (3–7) were fed on the basal diet and given an aqueous solution of mercuric chloride (25 ppm mercuric) in drinking water together with the herbal antioxidant extracts and probiotics (25 ml/rat/day) throughout the experimental period. Where, group3 (Hg/CO) given coriander extract, group4 (Hg/DA) given dandelion extract, group5 (Hg/DS) given date palm seeds extract, group6 (Hg/PS) given probiotic supernatant, and group7 (Hg/Mix) given mixture of equal quantities of probiotic supernatant together with the three herbal extracts. The treatment lasted for 6 weeks, animals were sacrificed and blood samples were collected. Blood testosterone, enzyme activity and histopathological sections were performed. Results The obtained data exhibited that mercury intoxication revealed increases of lactic dehydrogenase and decreases of glutathione-s-transferase and testosterone. Light microscopic investigations of the brain cortex and cerebellum were suggestive of multiple foci of inflammation, cellular infiltration, gliosis and degeneration. Moreover, decreased glial fibrillary acidic protein (GFAP)-immunoreactivity and potential astrocyte toxicity both reflected impaired neuro-protective function of astrocytes necessary for maintaining the brain structure and function. Conclusion Administration of the herbal extracts and their mixture with probiotics enhance the body defense and contain protective factor against mercury neurotoxicity and for maintaining normal testosterone levels in male rats. Also, treatment restored the normal control levels of biochemical attributes and histological architecture.
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Tan Q, Zhang M, Geng L, Xia Z, Li C, Usman M, Du Y, Wei L, Bi H. Hormesis of methylmercury-human serum albumin conjugate on N9 microglia via ERK/MAPKs and STAT3 signaling pathways. Toxicol Appl Pharmacol 2018; 362:59-66. [PMID: 30352208 DOI: 10.1016/j.taap.2018.10.017] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Revised: 09/18/2018] [Accepted: 10/19/2018] [Indexed: 10/28/2022]
Abstract
Methylmercury (MeHg+) is an extremely toxic organomercury cation that can induce severe neurological damage. Once it enters the body, methylmercury binds to amino acids or proteins containing free sulfhydryl groups. In particular, methylmercury is known to bind with human serum albumin (HSA) in human plasma; however, the effects of methylmercury-HSA conjugate (MeHg-HSA) on the central nervous system (CNS) are not fully understood. In the present study, we used the microglial cell line N9 as the target cells to evaluate the effect of MeHg-HSA on physiological function of the CNS preliminarily. The various factors in the cell culture were monitored by MTT assay, total lactate dehydrogenase assay, ELISA, qPCR, Western blot and flow cytometry techniques. The results showed that low-dose treatment with MeHg-HSA activated N9 cells, promoting cell proliferation and total cell number, enhancing NO and intracellular Ca2+ levels, and suppressing the release of TNFα and IL1β without cytotoxic effects; while high-dose MeHg-HSA exhibited cytotoxic effects on N9 cells, including promoting cell death and increasing the secretion of TNFα and IL1β. These results indicate that MeHg-HSA causes hormesis in microglia N9 cells. Furthermore, ERK/MAPKs and STAT3 signaling pathways related to the hormesis of MeHg-HSA on N9 cells. In addition, low dose of MeHg-HSA might be viewed as something very close to a lowest observed adverse effect level (LOAEL) for N9 cells. These findings will be useful for investigating the hormesis mechanism of MeHg+ and exploring the specific functions of MeHg-sulfhydryl conjugates on the central nervous system.
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Affiliation(s)
- Qiaozhu Tan
- Qinghai Provincial Key Laboratory of Tibetan Medicine Pharmacology and Safety Evaluation, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining, China; University of Chinese Academy of Sciences, Beijing, China
| | - Ming Zhang
- Qinghai Provincial Key Laboratory of Tibetan Medicine Pharmacology and Safety Evaluation, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining, China; University of Chinese Academy of Sciences, Beijing, China
| | - Lujing Geng
- Qinghai Provincial Key Laboratory of Tibetan Medicine Pharmacology and Safety Evaluation, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining, China; University of Chinese Academy of Sciences, Beijing, China
| | - Zhenghua Xia
- Qinghai Provincial Key Laboratory of Tibetan Medicine Pharmacology and Safety Evaluation, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining, China; University of Chinese Academy of Sciences, Beijing, China
| | - Cen Li
- Qinghai Provincial Key Laboratory of Tibetan Medicine Pharmacology and Safety Evaluation, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining, China; Key Laboratory of Tibetan Medicine Research, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining, China
| | - Muhammad Usman
- Department of Biotechnology, Virtual University of Pakistan, Lahore, Pakistan
| | - Yuzhi Du
- Qinghai Provincial Key Laboratory of Tibetan Medicine Pharmacology and Safety Evaluation, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining, China; Key Laboratory of Tibetan Medicine Research, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining, China
| | - Lixin Wei
- Qinghai Provincial Key Laboratory of Tibetan Medicine Pharmacology and Safety Evaluation, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining, China; Key Laboratory of Tibetan Medicine Research, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining, China.
| | - Hongtao Bi
- Qinghai Provincial Key Laboratory of Tibetan Medicine Pharmacology and Safety Evaluation, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining, China; Key Laboratory of Tibetan Medicine Research, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining, China.
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Yang B, Bai Y, Yin C, Qian H, Xing G, Wang S, Li F, Bian J, Aschner M, Lu R. Activation of autophagic flux and the Nrf2/ARE signaling pathway by hydrogen sulfide protects against acrylonitrile-induced neurotoxicity in primary rat astrocytes. Arch Toxicol 2018; 92:2093-2108. [PMID: 29725710 DOI: 10.1007/s00204-018-2208-x] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Accepted: 04/25/2018] [Indexed: 10/25/2022]
Abstract
Hydrogen sulfide (H2S), the third gasotransmitter, has been shown to act as a neuroprotective factor in numerous pathological processes; however, its underlying mechanism(s) of action remain unclear. It is widely accepted that activation of moderate autophagy and the Nrf2/ARE signaling pathway play important roles in the biological self-defense systems. In the present study, we investigated whether exogenous H2S protects against the cytotoxicity of acrylonitrile (AN), a neurotoxin, in primary rat astrocytes. We found that pretreatment for 1 h with sodium hydrosulfide (NaHS), a donor of H2S (200-800 µM), significantly attenuated the AN-induced decrease in cell viability, increase in lactate dehydrogenase release and morphological changes. Furthermore, NaHS significantly attenuated AN-induced oxidative stress by reducing reactive oxygen species (ROS) levels and increasing glutathione (GSH) concentration. Moreover, NaHS activated the autophagic flux, detectable as a change in autophagy-related proteins (Beclin-1, Atg5 and p62), the formation of acidic vesicular organelles and LC3B aggregation, confirmed by adenoviral expression of mRFP-GFP-LC3. Additionally, NaHS stimulated translocation of Nrf2 into the nucleus and increased expression of heme oxygenase-1 and γ-glutamylcysteine synthetase, downstream targets of Nrf2. Notably, the autophagy inhibitor 3-methyladenine and Beclin-1, or Nrf2-targeted siRNA, significantly attenuated the neuroprotective effects of NaHS against AN-induced neurotoxicity. In conclusion, we identified a crucial role of autophagy and the Nrf2/ARE signaling pathway in H2S-mediated neuroprotection against AN-induced toxicity in primary rat astrocytes. Our findings provide novel insights into the mechanisms of H2S-mediated neuroprotection, and suggest that H2S-based donors may serve as potential new candidate drugs to treat AN-induced neurotoxicity.
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Affiliation(s)
- Bobo Yang
- Department of Preventive Medicine and Public Health Laboratory Sciences, School of Medicine, Jiangsu University, 301 Xuefu Road, Zhenjiang, 212013, Jiangsu, China
| | - Yu Bai
- Department of Preventive Medicine and Public Health Laboratory Sciences, School of Medicine, Jiangsu University, 301 Xuefu Road, Zhenjiang, 212013, Jiangsu, China
| | - Changsheng Yin
- Department of Preventive Medicine and Public Health Laboratory Sciences, School of Medicine, Jiangsu University, 301 Xuefu Road, Zhenjiang, 212013, Jiangsu, China.,Institute of Life Sciences, Jiangsu University, 301 Xuefu Road, Zhenjiang, 212013, Jiangsu, China
| | - Hai Qian
- Department of Preventive Medicine and Public Health Laboratory Sciences, School of Medicine, Jiangsu University, 301 Xuefu Road, Zhenjiang, 212013, Jiangsu, China
| | - Guangwei Xing
- Department of Preventive Medicine and Public Health Laboratory Sciences, School of Medicine, Jiangsu University, 301 Xuefu Road, Zhenjiang, 212013, Jiangsu, China
| | - Suhua Wang
- Department of Preventive Medicine and Public Health Laboratory Sciences, School of Medicine, Jiangsu University, 301 Xuefu Road, Zhenjiang, 212013, Jiangsu, China
| | - Fang Li
- Department of Preventive Medicine and Public Health Laboratory Sciences, School of Medicine, Jiangsu University, 301 Xuefu Road, Zhenjiang, 212013, Jiangsu, China
| | - Jinsong Bian
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117600, Singapore
| | - Michael Aschner
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY, 10461, USA
| | - Rongzhu Lu
- Department of Preventive Medicine and Public Health Laboratory Sciences, School of Medicine, Jiangsu University, 301 Xuefu Road, Zhenjiang, 212013, Jiangsu, China. .,Center for Experimental Research, Kunshan Hospital Affiliated to Jiangsu University, 91 Qianjin(W) Road, Kunshan, 215132, Jiangsu, China.
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Barbosa NV, Nogueira CW, Nogara PA, de Bem AF, Aschner M, Rocha JBT. Organoselenium compounds as mimics of selenoproteins and thiol modifier agents. Metallomics 2017; 9:1703-1734. [PMID: 29168872 DOI: 10.1039/c7mt00083a] [Citation(s) in RCA: 91] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Selenium is an essential trace element for animals and its role in the chemistry of life relies on a unique functional group: the selenol (-SeH) group. The selenol group participates in critical redox reactions. The antioxidant enzymes glutathione peroxidase (GPx) and thioredoxin reductase (TrxR) exemplify important selenoproteins. The selenol group shares several chemical properties with the thiol group (-SH), but it is much more reactive than the sulfur analogue. The substitution of S by Se has been exploited in organic synthesis for a long time, but in the last 4 decades the re-discovery of ebselen (2-phenyl-1,2-benzisoselenazol-3(2H)-one) and the demonstration that it has antioxidant and therapeutic properties has renovated interest in the field. The ability of ebselen to mimic the reaction catalyzed by GPx has been viewed as the most important molecular mechanism of action of this class of compound. The term GPx-like or thiol peroxidase-like reaction was previously coined in the field and it is now accepted as the most important chemical attribute of organoselenium compounds. Here, we will critically review the literature on the capacity of organoselenium compounds to mimic selenoproteins (particularly GPx) and discuss some of the bottlenecks in the field. Although the GPx-like activity of organoselenium compounds contributes to their pharmacological effects, the superestimation of the GPx-like activity has to be questioned. The ability of these compounds to oxidize the thiol groups of proteins (the thiol modifier effects of organoselenium compounds) and to spare selenoproteins from inactivation by soft-electrophiles (MeHg+, Hg2+, Cd2+, etc.) might be more relevant for the explanation of their pharmacological effects than their GPx-like activity. In our view, the exploitation of the thiol modifier properties of organoselenium compounds can be harnessed more rationally than the use of low mass molecular structures to mimic the activity of high mass macromolecules that have been shaped by millions to billions of years of evolution.
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Affiliation(s)
- Nilda V Barbosa
- Departamento de Bioquímica e Biologia Molecular, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Santa Maria, RS, Brazil.
| | - Cristina W Nogueira
- Departamento de Bioquímica e Biologia Molecular, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Santa Maria, RS, Brazil.
| | - Pablo A Nogara
- Departamento de Bioquímica e Biologia Molecular, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Santa Maria, RS, Brazil.
| | - Andreza F de Bem
- Departamento de Bioquímica, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil
| | - Michael Aschner
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, New York, USA
| | - João B T Rocha
- Departamento de Bioquímica e Biologia Molecular, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Santa Maria, RS, Brazil.
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Branco V, Coppo L, Solá S, Lu J, Rodrigues CMP, Holmgren A, Carvalho C. Impaired cross-talk between the thioredoxin and glutathione systems is related to ASK-1 mediated apoptosis in neuronal cells exposed to mercury. Redox Biol 2017; 13:278-287. [PMID: 28600984 PMCID: PMC5466585 DOI: 10.1016/j.redox.2017.05.024] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Revised: 05/29/2017] [Accepted: 05/30/2017] [Indexed: 12/22/2022] Open
Abstract
Mercury (Hg) compounds target both cysteine (Cys) and selenocysteine (Sec) residues in peptides and proteins. Thus, the components of the two major cellular antioxidant systems - glutathione (GSH) and thioredoxin (Trx) systems - are likely targets for mercurials. Hg exposure results in GSH depletion and Trx and thioredoxin reductase (TrxR) are prime targets for mercury. These systems have a wide-range of common functions and interaction between their components has been reported. However, toxic effects over both systems are normally treated as isolated events. To study how the interaction between the glutathione and thioredoxin systems is affected by Hg, human neuroblastoma (SH-SY5Y) cells were exposed to 1 and 5μM of inorganic mercury (Hg2+), methylmercury (MeHg) or ethylmercury (EtHg) and examined for TrxR, GSH and Grx levels and activities, as well as for Trx redox state. Phosphorylation of apoptosis signalling kinase 1 (ASK1), caspase-3 activity and the number of apoptotic cells were evaluated to investigate the induction of Trx-mediated apoptotic cell death. Additionally, primary cerebellar neurons from mice depleted of mitochondrial Grx2 (mGrx2D) were used to examine the link between Grx activity and Trx function. Results showed that Trx was affected at higher exposure levels than TrxR, especially for EtHg. GSH levels were only significantly affected by exposure to a high concentration of EtHg. Depletion of GSH with buthionine sulfoximine (BSO) severely increased Trx oxidation by Hg. Notably, EtHg-induced oxidation of Trx was significantly enhanced in primary neurons of mGrx2D mice. Our results suggest that GSH/Grx acts as backups for TrxR in neuronal cells to maintain Trx turnover during Hg exposure, thus linking different mechanisms of molecular and cellular toxicity. Finally, Trx oxidation by Hg compounds was associated to apoptotic hallmarks, including increased ASK-1 phosphorylation, caspase-3 activation and increased number of apoptotic cells.
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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.
| | - Lucia Coppo
- Division of Biochemistry, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, SE-171 77 Stockholm, Sweden
| | - Susana Solá
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal
| | - Jun Lu
- School of Pharmaceutical Sciences, Southwest University, 2# Tiansheng Road, Beibei District, Chongqing 400715, PR China
| | - Cecília M P Rodrigues
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal
| | - Arne Holmgren
- Division of Biochemistry, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, SE-171 77 Stockholm, Sweden
| | - 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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Wang X, Fan X, Yuan S, Jiao W, Liu B, Cao J, Jiang W. Chlorogenic acid protects against aluminium-induced cytotoxicity through chelation and antioxidant actions in primary hippocampal neuronal cells. Food Funct 2017; 8:2924-2934. [PMID: 28745369 DOI: 10.1039/c7fo00659d] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Chlorogenic acid (CGA), a major polyphenolic component of many plants, displays antioxidant and neuroprotective properties in neurodegenerative diseases. To investigate whether CGA may influence aluminium (Al) induced cytotoxicity, aluminium chloride (50 μM Al) was administered in primary hippocampal neuronal cells presupplemented with CGA (10, 50 and 100 μM). Our study shows that the exposure to Al caused cell death, Al3+ accumulation, reactive oxygen species generation and mitochondrial damage in cells. The administration of CGA (50 μM) increased cell viability by 37.5%, decreased the levels of Al3+ by 26.0%, together with significantly weakening the oxidative damage compared with Al treatment alone. CGA protected neurons against Al-induced oxidative stress by increasing the expression of nuclear factor-E2-related factor 2 and its target phase 2 enzymes. The administration of CGA remarkably promoted the activities of superoxide dismutase, catalase, glutathione peroxidase, glutathione S-transferase, creatine kinase and acetylcholinesterase and attenuated the rate of ATP hydrolysis. Our finding shows that CGA has neuroprotective effects against Al-induced cytotoxicity by chelation and antioxidant activation.
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Affiliation(s)
- Xiaomei Wang
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, People's Republic of China.
| | - Xinguang Fan
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, People's Republic of China.
| | - Shuzhi Yuan
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, People's Republic of China.
| | - Wenxiao Jiao
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, People's Republic of China.
| | - Bangdi Liu
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, People's Republic of China.
| | - Jiankang Cao
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, People's Republic of China.
| | - Weibo Jiang
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, People's Republic of China.
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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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36
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Culbreth M, Zhang Z, Aschner M. Methylmercury augments Nrf2 activity by downregulation of the Src family kinase Fyn. Neurotoxicology 2017; 62:200-206. [PMID: 28736149 DOI: 10.1016/j.neuro.2017.07.028] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Revised: 07/17/2017] [Accepted: 07/17/2017] [Indexed: 12/26/2022]
Abstract
Methylmercury (MeHg) is a potent developmental neurotoxicant that induces an oxidative stress response in the brain. It has been demonstrated that MeHg exposure increases nuclear factor erythroid 2-related factor 2 (Nrf2) activity. Nrf2 is a transcription factor that translocates to the nucleus in response to oxidative stress, and upregulates phase II detoxifying enzymes. Although, Nrf2 activity is augmented subsequent to MeHg exposure, it has yet to be established whether Nrf2 moves into the nucleus as a result. Furthermore, the potential effect MeHg might have on the non-receptor tyrosine kinase, Fyn, has not been addressed. Fyn phosphorylates Nrf2 in the nucleus, resulting in its inactivation, and consequent downregulation of the oxidative stress response. Here, we observe Nrf2 translocates to the nucleus subsequent to MeHg-induced oxidative stress. This response is concomitant with reduced Fyn expression and nuclear localization. Moreover, we detected an increase in phosphorylated Akt and glycogen synthase kinase 3 beta (GSK-3β) at activating and inhibitory sites, respectively. Akt phosphorylates and inhibits GSK-3β, which subsequently prevents Fyn phosphorylation to signal nuclear import. Our results demonstrate MeHg downregulates Fyn to maintain Nrf2 activity, and further illuminate a potential mechanism by which MeHg elicits neurotoxicity.
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Affiliation(s)
- Megan Culbreth
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY, United States.
| | - Ziyan Zhang
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY, United States
| | - Michael Aschner
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY, United States
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Mohamed NES, Abd El-Moneim AE. Ginkgo biloba extract alleviates oxidative stress and some neurotransmitters changes induced by aluminum chloride in rats. Nutrition 2017; 35:93-99. [DOI: 10.1016/j.nut.2016.10.012] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Revised: 10/16/2016] [Accepted: 10/17/2016] [Indexed: 12/26/2022]
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Yang T, Xu Z, Liu W, Feng S, Li H, Guo M, Deng Y, Xu B. Alpha-lipoic acid reduces methylmercury-induced neuronal injury in rat cerebral cortex via antioxidation pathways. ENVIRONMENTAL TOXICOLOGY 2017; 32:931-943. [PMID: 27298056 DOI: 10.1002/tox.22294] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2016] [Revised: 05/18/2016] [Accepted: 05/22/2016] [Indexed: 06/06/2023]
Abstract
Methylmercury (MeHg), an extremely dangerous environmental pollutant, accumulating preferentially in central nervous system, causes a series of cytotoxic effects. The present study explored the mechanisms which contribute to MeHg-induced neurotoxicity focusing on the oxidative stress in rat cerebral cortex. In addition, the protective effects of alpha-lipoic acid (LA), a potent antioxidant on MeHg-mediated neuronal injury, was also investigated in current study. A MeHg poisoning model was established as 64 rats randomly divided into 4 groups of which saline control group, MeHg-treated groups (4 and 12 μmol kg-1 ), and LA pretreatment (35 μmol kg-1 ) group, respectively. After administration of 12 μmol kg-1 MeHg for 4 weeks, it was found that obvious pathological changes and apoptosis in neuronal cells. Meanwhile, total Hg levels elevated significantly, superoxide dismutase (SOD) and gluthathione peroxidase (GSH-Px) activities were inhibited, and ROS formation elevated, which might be critical to aggravate oxidative stress in cerebral cortex. In addition, NF-E2-related factor 2 (Nrf2) pathways were activated, as heme oxygenase-1 (HO-1) and γ-glutamylcysteine synthetase heavy subunit (γ-GCSh) expressions were up-regulated obviously by MeHg exposure. Moreover, activities of Na+ -K+ -ATPase and Ca2+ -ATPase were inhibited, leading to intracellular calcium (Ca2+ ) overload. LA pre-treatment partially reduced MeHg neurotoxic effects via anti-oxidation pathways. In conclusion, these findings clearly indicated that MeHg aggravated oxidative stress and Ca2+ overload in cerebral cortex. LA possesses the ability to prevent MeHg neurotoxicity through its anti-oxidative properties. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 931-943, 2017.
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Affiliation(s)
- Tianyao Yang
- Department of Environmental Health, School of Public Health, China Medical University, Shenyang, Liaoning Province, 110122, People's Republic of China
| | - Zhaofa Xu
- Department of Environmental Health, School of Public Health, China Medical University, Shenyang, Liaoning Province, 110122, People's Republic of China
| | - Wei Liu
- Department of Environmental Health, School of Public Health, China Medical University, Shenyang, Liaoning Province, 110122, People's Republic of China
| | - Shu Feng
- Department of Environmental Health, School of Public Health, China Medical University, Shenyang, Liaoning Province, 110122, People's Republic of China
| | - Hongpeng Li
- Department of Environmental Health, School of Public Health, China Medical University, Shenyang, Liaoning Province, 110122, People's Republic of China
| | - Meixin Guo
- Department of Environmental Health, School of Public Health, China Medical University, Shenyang, Liaoning Province, 110122, People's Republic of China
| | - Yu Deng
- Department of Environmental Health, School of Public Health, China Medical University, Shenyang, Liaoning Province, 110122, People's Republic of China
| | - Bin Xu
- Department of Environmental Health, School of Public Health, China Medical University, Shenyang, Liaoning Province, 110122, People's Republic of China
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Taïr K, Kharoubi O, Taïr OA, Hellal N, Benyettou I, Aoues A. Aluminium-induced acute neurotoxicity in rats: Treatment with aqueous extract of Arthrophytum (Hammada scoparia). JOURNAL OF ACUTE DISEASE 2016. [DOI: 10.1016/j.joad.2016.08.028] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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40
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Mariano DOC, de Souza D, Meinerz DF, Allebrandt J, de Bem AF, Hassan W, Rodrigues OED, da Rocha JBT. The potential toxicological insights about the anti-HIV drug azidothymidine-derived monoselenides in human leukocytes: Toxicological insights of new selenium-azidothymidine analogs. Hum Exp Toxicol 2016; 36:910-918. [DOI: 10.1177/0960327116674529] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Acquired immunodeficiency syndrome (AIDS) is a worldwide disease characterized by impairments of immune function. AIDS can be associated with oxidative stress (OS) that can be linked to selenium (Se) deficiency. Se is fundamental for the synthesis of selenoproteins, such as glutathione peroxidase and thioredoxin reductase. These enzymes catalyze the decomposition of reactive oxygen species and contribute to maintain equilibrium in cell redox status. Literature data indicate that organoselenium compounds, such as ebselen and diphenyl diselenide, have antioxidant properties in vitro and in vivo models associated with OS. Nevertheless, selenocompounds can also react and oxidize thiols groups, inducing toxicity in mammals. Here, we tested the potential cytotoxic and genotoxic properties of six analogs of the prototypal anti-HIV drug azidothymidine (AZT) containing Se (5′-Se-(phenyl)zidovudine; 5′-Se-(1,3,5-trimethylphenyl)zidovudine; 5′-Se-(1-naphtyl)zidovudine; 5′-Se-(4-chlorophenyl)zidovudine) (C4); 5′-Se-(4-methylphenyl)zidovudine (C5); and 5′-(4-methylbenzoselenoate)zidovudine). C5 increased the rate of dithiothreitol oxidation (thiol oxidase activity) and C2-C4 and C6 (at 100 µM) increased DNA damage index (DI) in human leukocytes. Moreover, C5 (200 µM) decreased human leukocyte viability to about 50%. Taken together, these results indicated the low in vitro toxicity in human leukocytes of some Se-containing analogs of AZT.
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Affiliation(s)
- DOC Mariano
- Departamento de Bioquímica e Biologia Molecular, Universidade Federal de Santa Maria, Santa Maria, Brazil
| | - D de Souza
- Departamento de Bioquímica e Biologia Molecular, Universidade Federal de Santa Maria, Santa Maria, Brazil
| | - DF Meinerz
- Departamento de Bioquímica e Biologia Molecular, Universidade Federal de Santa Maria, Santa Maria, Brazil
| | - J Allebrandt
- Departamento de Bioquímica e Biologia Molecular, Universidade Federal de Santa Maria, Santa Maria, Brazil
| | - AF de Bem
- Departamento de Bioquímica, Universidade Federal de Santa Catarina, Santa Catarina, Brazil
| | - W Hassan
- Departamento de Bioquímica e Biologia Molecular, Universidade Federal de Santa Maria, Santa Maria, Brazil
| | - OED Rodrigues
- Departamento de Química, Universidade Federal de Santa Maria, Santa Maria, Brazil
| | - JBT da Rocha
- Departamento de Bioquímica e Biologia Molecular, Universidade Federal de Santa Maria, Santa Maria, Brazil
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Shao Y, Figeys D, Ning Z, Mailloux R, Chan HM. Methylmercury can induce Parkinson's-like neurotoxicity similar to 1-methyl-4- phenylpyridinium: a genomic and proteomic analysis on MN9D dopaminergic neuron cells. J Toxicol Sci 2016; 40:817-28. [PMID: 26558463 DOI: 10.2131/jts.40.817] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Exposure to environmental chemicals has been implicated as a possible risk factor for the development of neurodegenerative diseases. Our previous study showed that methylmercury (MeHg) exposure can disrupt synthesis, uptake and metabolism of dopamine similar to 1-methyl-4-phenylpyridinium (MPP(+)). The objective of this study was to investigate the effects of MeHg exposure on gene and protein profiles in a dopaminergic MN9D cell line. MN9D cells were treated with MeHg (1-5 μM) and MPP(+) (10-40 μM) for 48 hr. Real-time PCR Parkinson's disease (PD) arrays and high-performance liquid chromatography/electrospray ionization tandem mass spectrometry (HPLC-ESI-MS/MS) were performed for the analysis. PD PCR array results showed that 19% genes were significantly changed in the 2.5 μM MeHg treated cells, and 39% genes were changed in the 5 μM MeHg treated cells. In comparison, MPP(+) treatment (40 µM) resulted in significant changes in 25% genes. A total of 15 common genes were altered by both MeHg and MPP(+), and dopaminergic signaling transduction was the most affected pathway. Proteomic analysis identified a total of 2496 proteins, of which 188, 233 and 395 proteins were differentially changed by 1 μM and 2.5 μM MeHg, and MPP(+) respectively. A total of 61 common proteins were changed by both MeHg and MPP(+) treatment. The changed proteins were mainly involved in energetic generation-related metabolism pathway (propanoate metabolism, pyruvate metabolism and fatty acid metabolism), oxidative phosphorylation, proteasome, PD and other neurodegenerative disorders. A total of 7 genes/proteins including Ube2l3 (Ubiquitin-conjugating enzyme E2 L3) and Th (Tyrosine 3-monooxygenase) were changed in both genomic and proteomic analysis. These results suggest that MeHg and MPP(+) share many similar signaling pathways leading to the pathogenesis of PD and other neurodegenerative diseases.
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Affiliation(s)
- Yueting Shao
- Natural Resources and Environmental Studies Program, University of Northern British Columbia, Canada
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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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43
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Jantas D, Piotrowski M, Lason W. An Involvement of PI3-K/Akt Activation and Inhibition of AIF Translocation in Neuroprotective Effects of Undecylenic Acid (UDA) Against Pro-Apoptotic Factors-Induced Cell Death in Human Neuroblastoma SH-SY5Y Cells. J Cell Biochem 2016; 116:2882-95. [PMID: 26012840 DOI: 10.1002/jcb.25236] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Accepted: 05/15/2015] [Indexed: 01/29/2023]
Abstract
Undecylenic acid (UDA), a naturally occurring 11-carbon unsaturated fatty acid, has been used for several years as an economical antifungal agent and a nutritional supplement. Recently, the potential usefulness of UDA as a neuroprotective drug has been suggested based on the ability of this agent to inhibit μ-calpain activity. In order to verify neuroprotective potential of UDA, we tested protective efficacy of this compound against cell damage evoked by pro-apoptotic factors (staurosporine and doxorubicin) and oxidative stress (hydrogen peroxide) in human neuroblastoma SH-SY5Y cells. We showed that UDA partially protected SH-SY5Y cells against the staurosporine- and doxorubicin-evoked cell death; however, this effect was not connected with its influence on caspase-3 activity. UDA decreased the St-induced changes in mitochondrial and cytosolic AIF level, whereas in Dox-model it affected only the cytosolic AIF content. Moreover, UDA (1-40 μM) decreased the hydrogen peroxide-induced cell damage which was connected with attenuation of hydrogen peroxide-mediated necrotic (PI staining, ADP/ATP ratio) and apoptotic (mitochondrial membrane potential, caspase-3 activation, AIF translocation) changes. Finally, we demonstrated that an inhibitor of PI3-K/Akt (LY294002) but not MAPK/ERK1/2 (U0126) pathway blocked the protection mediated by UDA in all tested models of SH-SY5Y cell injury. These in vitro data point to UDA as potentially effective neuroprotectant the utility of which should be further validated in animal studies.
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Affiliation(s)
- Danuta Jantas
- Department of Experimental Neuroendocrinology, Institute of Pharmacology, Polish Academy of Sciences, Krakow, Poland
| | - Marek Piotrowski
- Jerzy Haber Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences, Krakow, Poland
| | - Wladyslaw Lason
- Department of Experimental Neuroendocrinology, Institute of Pharmacology, Polish Academy of Sciences, Krakow, Poland
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Yu B, Wenjun Z, Changsheng Y, Yuntao F, Jing M, Ben L, Hai Q, Guangwei X, Suhua W, Fang L, Aschner M, Rongzhu L. Preconditioning of endoplasmic reticulum stress protects against acrylonitrile-induced cytotoxicity in primary rat astrocytes: The role of autophagy. Neurotoxicology 2016; 55:112-121. [DOI: 10.1016/j.neuro.2016.05.020] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2015] [Revised: 05/27/2016] [Accepted: 05/28/2016] [Indexed: 01/06/2023]
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Liu W, Xu Z, Yang T, Deng Y, Xu B, Feng S. Tea Polyphenols Protect Against Methylmercury-Induced Cell Injury in Rat Primary Cultured Astrocytes, Involvement of Oxidative Stress and Glutamate Uptake/Metabolism Disorders. Mol Neurobiol 2016; 53:2995-3009. [PMID: 25952541 DOI: 10.1007/s12035-015-9161-y] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Accepted: 03/25/2015] [Indexed: 02/06/2023]
Abstract
Methylmercury (MeHg) is an extremely dangerous environmental contaminant, accumulating preferentially in CNS and causing a series of cytotoxic effects. However, the precise mechanisms are still incompletely understood. The current study explored the mechanisms that contribute to MeHg-induced cell injury focusing on the oxidative stress and Glu uptake/metabolism disorders in rat primary cultured astrocytes. Moreover, the neuroprotective effects of tea polyphenols (TP), a natural antioxidant, against MeHg cytotoxicity were also investigated. Astrocytes were exposed to 0, 2.5, 5, 10, and 20 μM MeHgCl for 6-30 h, or pretreated with 50, 100, 200, and 400 μM TP for 1-12 h; cell viability and LDH release were then determined. For further experiments, 50, 100, and 200 μM of TP pretreatment for 6 h followed by 10 μM MeHgCl for 24 h were performed for the examination of the responses of astrocytes, specifically addressing NPSH levels, ROS generation, ATPase activity, the expressions of Nrf2 pathway as well as Glu metabolism enzyme GS and Glu transporters (GLAST and GLT-1). Exposure of MeHg resulted in damages of astrocytes, which were shown by a loss of cell viability, and supported by high levels of LDH release, morphological changes, apoptosis rates, and NPSH depletion. In addition, astrocytes were sensitive to MeHg-mediated oxidative stress, a finding that is consistent with ROS overproduction; Nrf2 as well as its downstream genes HO-1 and γ-GCSh were markedly upregulated. Moreover, MeHg significantly inhibited GS activity, as well as expressions of GS, GLAST, and GLT-1. On the contrary, pretreatment with TP presented a concentration-dependent prevention against MeHg-mediated cytotoxic effects of astrocytes. In conclusion, the findings clearly indicated that MeHg aggravated oxidative stress and Glu uptake/metabolism dysfunction in astrocytes. TP possesses some abilities to prevent MeHg cytotoxicity through its antioxidative properties.
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Affiliation(s)
- Wei Liu
- Department of Environmental Health, School of Public Health, China Medical University, Shenyang, 110122, Liaoning province, China
| | - Zhaofa Xu
- Department of Environmental Health, School of Public Health, China Medical University, Shenyang, 110122, Liaoning province, China.
| | - Tianyao Yang
- Department of Environmental Health, School of Public Health, China Medical University, Shenyang, 110122, Liaoning province, China
| | - Yu Deng
- Department of Environmental Health, School of Public Health, China Medical University, Shenyang, 110122, Liaoning province, China
| | - Bin Xu
- Department of Environmental Health, School of Public Health, China Medical University, Shenyang, 110122, Liaoning province, China
| | - Shu Feng
- Department of Environmental Health, School of Public Health, China Medical University, Shenyang, 110122, Liaoning province, China
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46
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Selenium and mercury levels in rat liver slices co-treated with diphenyl diselenide and methylmercury. Biometals 2016; 29:543-50. [DOI: 10.1007/s10534-016-9936-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2016] [Accepted: 04/24/2016] [Indexed: 11/25/2022]
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47
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Wu J, Cheng G, Lu Z, Wang M, Tian J, Bi Y. Effects of Methyl Mercury Chloride on Rat Hippocampus Structure. Biol Trace Elem Res 2016; 171:124-30. [PMID: 26358766 PMCID: PMC4832005 DOI: 10.1007/s12011-015-0492-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Accepted: 08/21/2015] [Indexed: 12/02/2022]
Abstract
The objective of this study is to investigate the impacts of Methyl Mercury Chloride (MMC) on cognitive functions and ultrastructural changes of hippocampus in Sprague Dawley (SD) rats. Thirty healthy 20-day-old male SD rats weighing 30-40 g were randomly divided into three groups to receive daily injections. Two different dose levels were used: 4 mg/kg as high dose (H-MMC) and 2 mg/kg as low dose (L-MMC).The control group received 4 mg/kg saline solution (N-NaCl). After daily subcutaneous injection for 50 days, 6-day Morris water maze tests were used to assess the learning and memory functions of the rats. After a 5-day continuous training, spatial probe tests were conducted of times and paths crossing to the target quadrant on the 6th day. After the rats were euthanized, their hippocampus sections were stained with hematoxylin and eosin and analyzed under bothoptical microscope and electron microscope. The time H-MMC group spent in finding platform was significantly longer as compared toN-NaCl group on day 2 to day 5 and L-MMC group on day 4 to day 5. The number of crossing times of H-MMC group to the target quadrant was 0.63 ± 0.74, which is much lower than C-NaCl group (3.13 ± 1.56) with P value <0.05. No statistically significant difference in crossing times was found between L-MMC and C-NaCl groups. For H-MMC group, decreasing number of neurons and disorganized nerve cells were examined under light microscope. Swelling and dissolution of Golgi complex were examined under electron microscope, along with endoplasmic reticulum expansion and cytoplasmic edema. Mild cytoplasmic edema was found in L-MMC group. MMC can cause cognitive impairment in terms of learning and memory in SD rats. Additionally, it can also cause changes in the ultrastructure of neurons and morphological changes in the hippocampus, causing significant damage.
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Affiliation(s)
- Jingwei Wu
- Department of Radiology, Zhongnan Hospital of Wuhan University, Wuhan, China
- Department of Radiology, Hainan Provincial Nongken Hospital, Haikou, China
| | - Guangyuan Cheng
- Department of Radiology, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Zhiyan Lu
- Department of Radiology, Zhongnan Hospital of Wuhan University, Wuhan, China.
| | - Mingyue Wang
- Department of Radiology, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Jianying Tian
- Department of Anatomy, Ningxia Medical University, Yinchuan, China
| | - Yongyi Bi
- School of Public Health, Wuhan University, Wuhan, China
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48
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de Oliveira Souza VC, de Marco KC, Laure HJ, Rosa JC, Barbosa F. A brain proteome profile in rats exposed to methylmercury or thimerosal (ethylmercury). JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 2016; 79:502-512. [PMID: 27294299 DOI: 10.1080/15287394.2016.1182003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Exposure to organomercurials has been associated with harmful effects on the central nervous system (CNS). However, the mechanisms underlying organomercurial-mediated neurotoxic effects need to be elucidated. Exposure to toxic elements may promote cellular modifications such as alterations in protein synthesis in an attempt to protect tissues and organs from damage. In this context, the use of a "proteomic profile" is an important tool to identify potential early biomarkers or targets indicative of neurotoxicity. The aim of this study was to investigate potential modifications in rat cerebral cell proteome following exposure to methylmercury (MeHg) or ethylmercury (EtHg). For MeHg exposure, animals were administered by gavage daily 140 µg/kg/d of Hg (as MeHg) for 60 d and sacrificed 24 h after the last treatment. For EtHg exposure, 800 µg/kg/d of Hg (as EtHg) was given intramuscularly (im) in a single dose and rats were sacrificed after 4 h. Control groups received saline either by gavage or im. After extraction of proteins from whole brain samples and separation by two-dimensional electrophoresis (2-DE), 26 differentially expressed proteins were identified from exposed animals by matrix-assisted laser desorption ionization-time of flight (MALDI-TOF/TOF). Both MeHg and EtHg exposure induced an overexpression of calbindin, a protein that acts as a neuroprotective agent by (1) adjusting the concentration of Ca(2+) within cells and preventing neurodegenerative diseases and (2) decreasing expression of glutamine synthetase, a crucial protein involved in regulation of glutamate concentration in synaptic cleft. In contrast, expression of superoxide dismutase (SOD), a protein involved in antioxidant defense, was elevated in brain of MeHg-exposed animals. Taken together, our data provide new valuable information on the possible molecular mechanisms associated with MeHg- and EtHg-mediated toxicity in cerebral tissue. These observed protein alterations may be considered as biomarkers candidates for biological monitoring of organomercurial poisoning.
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Affiliation(s)
- Vanessa Cristina de Oliveira Souza
- a Department of Clinical, Bromatological and Toxicological Analysis, Faculty of Pharmaceutical Sciences of Ribeirão Preto , University of São Paulo , São Paulo , Brazil
| | - Kátia Cristina de Marco
- a Department of Clinical, Bromatological and Toxicological Analysis, Faculty of Pharmaceutical Sciences of Ribeirão Preto , University of São Paulo , São Paulo , Brazil
| | - Hélen Julie Laure
- b Department of Molecular and Cellular Biology, Faculty of Medicine of Ribeirão Preto , University of São Paulo , São Paulo , Brazil
| | - José Cesar Rosa
- b Department of Molecular and Cellular Biology, Faculty of Medicine of Ribeirão Preto , University of São Paulo , São Paulo , Brazil
| | - Fernando Barbosa
- a Department of Clinical, Bromatological and Toxicological Analysis, Faculty of Pharmaceutical Sciences of Ribeirão Preto , University of São Paulo , São Paulo , Brazil
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49
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Yu B, Changsheng Y, Wenjun Z, Ben L, Hai Q, Jing M, Guangwei X, Shuhua W, Fang L, Aschner M, Rongzhu L. Differential protection of pre- versus post-treatment with curcumin, Trolox, and N -acetylcysteine against acrylonitrile-induced cytotoxicity in primary rat astrocytes. Neurotoxicology 2015; 51:58-66. [DOI: 10.1016/j.neuro.2015.09.011] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2015] [Revised: 09/16/2015] [Accepted: 09/22/2015] [Indexed: 01/30/2023]
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50
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Mailloux RJ, Yumvihoze E, Chan HM. Superoxide anion radical (O2(-)) degrades methylmercury to inorganic mercury in human astrocytoma cell line (CCF-STTG1). Chem Biol Interact 2015; 239:46-55. [PMID: 26111762 DOI: 10.1016/j.cbi.2015.06.028] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Revised: 06/11/2015] [Accepted: 06/19/2015] [Indexed: 10/23/2022]
Abstract
Methylmercury (MeHg) is a global pollutant that is affecting the health of millions of people worldwide. However, the mechanism of MeHg toxicity still remains somewhat elusive and there is no treatment. It has been known for some time that MeHg can be progressively converted to inorganic mercury (iHg) in various tissues including the brain. Recent work has suggested that cleavage of the carbon-metal bond in MeHg in a biological environment is facilitated by reactive oxygen species (ROS). However, the oxyradical species that actually mediates this process has not been identified. Here, we provide evidence that superoxide anion radical (O2(-)) can convert MeHg to iHg. The calculated second-order rate constant for the degradation of 1μM MeHg by O2(-) generated by xanthine/xanthine oxidase was calculated to be 2×10(5)M(-1)s(-1). We were also able to show that this bioconversion can proceed in intact CCF-STTG1 human astrocytoma cells exposed to paraquat (PQ), a O2(-) generating viologen. Notably, exposure of cells to increasing amounts of PQ led to a dose dependent increase in both MeHg and iHg. Indeed, a 24h exposure to 500μM PQ induced a ∼13-fold and ∼18-fold increase in intracellular MeHg and iHg respectively. These effects were inhibited by superoxide dismutase mimetic MnTBAP. In addition, we also observed that a 24h exposure to a biologically relevant concentration of MeHg (1μM) did not induce cell death, oxidative stress, or even changes in cellular O2(-) and H2O2. However, co-exposure to PQ enhanced MeHg toxicity which was associated with a robust increase in cell death and oxidative stress. Collectively our results show that O2(-) can bioconvert MeHg to iHg in vitro and in intact cells exposed to conditions that simulate high intracellular O2(-) production. In addition, we show for the first time that O2(-) mediated degradation of MeHg to iHg enhances the toxicity of MeHg by facilitating an accumulation of both MeHg and iHg in the intracellular environment.
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Affiliation(s)
- Ryan J Mailloux
- University of Ottawa, Department of Biology, Center for Advanced Research in Environmental Genomics, Ottawa, ON K1N 6N5, Canada
| | - Emmanuel Yumvihoze
- University of Ottawa, Department of Biology, Center for Advanced Research in Environmental Genomics, Ottawa, ON K1N 6N5, Canada
| | - Hing Man Chan
- University of Ottawa, Department of Biology, Center for Advanced Research in Environmental Genomics, Ottawa, ON K1N 6N5, Canada.
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