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Spencer PS, Valdes Angues R, Palmer VS. Nodding syndrome: A role for environmental biotoxins that dysregulate MECP2 expression? J Neurol Sci 2024; 462:123077. [PMID: 38850769 DOI: 10.1016/j.jns.2024.123077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2023] [Revised: 05/15/2024] [Accepted: 05/30/2024] [Indexed: 06/10/2024]
Abstract
Nodding syndrome is an epileptic encephalopathy associated with neuroinflammation and tauopathy. This initially pediatric brain disease, which has some clinical overlap with Methyl-CpG-binding protein 2 (MECP2) Duplication Syndrome, has impacted certain impoverished East African communities coincident with local civil conflict and internal displacement, conditions that forced dependence on contaminated food and water. A potential role in Nodding syndrome for certain biotoxins (freshwater cyanotoxins plus/minus mycotoxins) with neuroinflammatory, excitotoxic, tauopathic, and MECP2-dysregulating properties, is considered here for the first time.
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Affiliation(s)
- Peter S Spencer
- Department of Neurology, School of Medicine and Oregon Institute of Occupational Health Sciences, Oregon Health & Science University, Portland, OR, USA; Oregon Institute of Occupational Health Sciences, Oregon Health & Science University, Portland, OR, USA; Gulu University School of Medicine, Gulu, Uganda.
| | - Raquel Valdes Angues
- Department of Neurology, School of Medicine and Oregon Institute of Occupational Health Sciences, Oregon Health & Science University, Portland, OR, USA
| | - Valerie S Palmer
- Department of Neurology, School of Medicine and Oregon Institute of Occupational Health Sciences, Oregon Health & Science University, Portland, OR, USA; Gulu University School of Medicine, Gulu, Uganda
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2
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Li SC, Gu LH, Wang YF, Wang LM, Chen L, Giesy JP, Tuo X, Xu WL, Wu QH, Liu YQ, Wu MH, Diao YY, Zeng HH, Zhang QB. A proteomic study on gastric impairment in rats caused by microcystin-LR. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 917:169306. [PMID: 38103614 DOI: 10.1016/j.scitotenv.2023.169306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 11/28/2023] [Accepted: 12/10/2023] [Indexed: 12/19/2023]
Abstract
Microcystins (MCs) are the most common cyanobacterial toxins. Epidemiological investigation showed that exposure to MCs can cause gastro-intestinal symptoms, gastroenteritis and gastric cancer. MCs can also accumulate in and cause histopathological damage to stomach. However, the exact mechanisms by which MCs cause gastric injury were unclear. In this study, Wistar rats were administrated 50, 75 or 100 μg microcystin-LR (MC-LR)/kg, body mass (bm) via tail vein, and histopathology, response of anti-oxidant system and the proteome of gastric tissues at 24 h after exposure were studied. Bleeding of fore-stomach and gastric corpus, inflammation and necrosis in gastric corpus and exfoliation of mucosal epithelial cells in gastric antrum were observed following acute MC-LR exposure. Compared with controls, activities of superoxide dismutase (SOD) were significantly greater in gastric tissues of exposed rats, while activities of catalase (CAT) were less in rats administrated 50 μg MC-LR/kg, bm, and concentrations of glutathione (GSH) and malondialdehyde (MDA) were greater in rats administrated 75 or 100 μg MC-LR/kg, bm. These results indicated that MC-LR could disrupt the anti-oxidant system and cause oxidative stress. The proteomic results revealed that MC-LR could affect expressions of proteins related to cytoskeleton, immune system, gastric functions, and some signaling pathways, including platelet activation, complement and coagulation cascades, and ferroptosis. Quantitative real-time PCR (qRT-PCR) analysis showed that transcriptions of genes for ferroptosis and gastric function were altered, which confirmed results of proteomics. Overall, this study illustrated that MC-LR could induce gastric dysfunction, and ferroptosis might be involved in MC-LR-induced gastric injury. This study provided novel insights into mechanisms of digestive diseases induced by MCs.
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Affiliation(s)
- Shang-Chun Li
- Environmental Health Effects and Risk Assessment Key Laboratory of Luzhou, School of Public Health, Southwest Medical University, Luzhou 646000, China
| | - Li-Hong Gu
- Environmental Health Effects and Risk Assessment Key Laboratory of Luzhou, School of Public Health, Southwest Medical University, Luzhou 646000, China
| | - Yan-Fang Wang
- Environmental Health Effects and Risk Assessment Key Laboratory of Luzhou, School of Public Health, Southwest Medical University, Luzhou 646000, China
| | - Li-Mei Wang
- Environmental Health Effects and Risk Assessment Key Laboratory of Luzhou, School of Public Health, Southwest Medical University, Luzhou 646000, China
| | - Liang Chen
- Qilu Lake Field Scientific Observation and Research Station for Plateau Shallow Lake in Yunnan Province, Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Kunming 650500, China; Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; State Key Laboratory of Eco-hydraulics in Northwest Arid Region, Faculty of Water Resources and Hydroelectric Engineering, Xi'an University of Technology, Xi'an 710048, China.
| | - John P Giesy
- Department of Veterinary Biomedical Sciences, Toxicology Centre, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5B3, Canada
| | - Xun Tuo
- College of Chemistry, Nanchang University, Nanchang 330031, China
| | - Wen-Li Xu
- Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Qian-Hui Wu
- School of Ecology and Environment, Anhui Normal University, Wuhu 241002, China
| | - Yi-Qing Liu
- Qilu Lake Field Scientific Observation and Research Station for Plateau Shallow Lake in Yunnan Province, Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Kunming 650500, China
| | - Ming-Huo Wu
- Environmental Health Effects and Risk Assessment Key Laboratory of Luzhou, School of Public Health, Southwest Medical University, Luzhou 646000, China
| | - Yang-Yang Diao
- Department of Pediatrics, Southwest Medical University, Luzhou 646000, China
| | - Hao-Hang Zeng
- Environmental Health Effects and Risk Assessment Key Laboratory of Luzhou, School of Public Health, Southwest Medical University, Luzhou 646000, China
| | - Qing-Bi Zhang
- Environmental Health Effects and Risk Assessment Key Laboratory of Luzhou, School of Public Health, Southwest Medical University, Luzhou 646000, China.
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Hu Z, Meng G, Zhang L, Zhang M, Cui H, Tang H. Protective effect of Huanglianjiedu Decoction on microcystin-LR induced nerve injury. Comp Biochem Physiol C Toxicol Pharmacol 2023; 272:109698. [PMID: 37442312 DOI: 10.1016/j.cbpc.2023.109698] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2023] [Revised: 06/26/2023] [Accepted: 07/09/2023] [Indexed: 07/15/2023]
Abstract
Microcystin-LR (MC-LR) presented in eutrophic water has been identified as having the capacity to induce damage to the mammalian nervous system by crossing the blood-brain barrier through organic anion transporting polypeptides. However, the lack of effective preventive and protective strategies remains a concern. Huanglianjiedu Decoction (HLJD), a classical Chinese traditional formula originating from the Tang Dynasty and comprising Rhizoma Coptidis, Radix Scutellariae, Cortex Phellodendri, and Fructus Gardeniae, has exhibited neuroprotective effects attributed to its antioxidant properties. In this study, we investigated the potential of HLJD in counteracting the neurotoxic effects induced by MC-LR. Our findings revealed that MC-LR dose-dependently inhibited the activity of the PP2A enzyme in PC 12 cells and significantly elevated the phosphorylation levels of JNK, ERK1/2, and p38. Moreover, MC-LR administration resulted in synaptic damage in mouse neurons, hyperphosphorylation of the microtubule-related protein Tau, cognitive impairment, and deficits in learning and memory in C57BL/6J mice. Notably, HLJD effectively reversed the cytotoxicity caused by MC-LR in PC 12 cells, and attenuated MC-LR-induced neuronal damage while improving learning ability in mice. These results highlight the potential of HLJD as a promising protective strategy against MC-LR-induced neurological injury.
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Affiliation(s)
- Zhengqiang Hu
- Department of Pharmacology, School of Basic Medical Sciences, Zhejiang University, Hangzhou 310058, China
| | - Guanmin Meng
- Department of Biochemistry, University of Alberta, Edmonton, AB, Canada; Department of Clinical Laboratory, Tongde Hospital of Zhejiang Province, Hangzhou, Zhejiang 310013, China
| | - Lejun Zhang
- Department of Pharmacology, School of Basic Medical Sciences, Zhejiang University, Hangzhou 310058, China
| | - Meng Zhang
- Department of Clinical Laboratory, Tongde Hospital of Zhejiang Province, Hangzhou, Zhejiang 310013, China
| | - Huashun Cui
- Department of Acupuncture and Moxibustion, Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai 200021, China.
| | - Huifang Tang
- Department of Pharmacology, School of Basic Medical Sciences, Zhejiang University, Hangzhou 310058, China.
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Dietary Thymoquinone Alone or Combined with Swimming Exercise Protect against Microcystin-LR-Induced Oxidative Injury in Mice. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2023; 2023:5643861. [PMID: 36874614 PMCID: PMC9977520 DOI: 10.1155/2023/5643861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/13/2022] [Accepted: 09/19/2022] [Indexed: 02/24/2023]
Abstract
Microcystin-leucine-arginine (MCLR) is the most abundant cyanotoxin produced by cyanobacteria. It induces potent cytotoxicity through oxidative stress and DNA damage. Thymoquinone (TQ) is a natural nutraceutical antioxidant derived from black cumin (Nigella sativa). Physical exercise (EX) improves whole-body metabolic homeostasis. Therefore, this study examined the protective role of swimming exercise and TQ against MC-induced toxicity in mice. Fifty-six healthy adult male albino mice (25-30 g) were randomized into seven groups; group (I) was the negative control and received oral physiological saline for 21 days; group (II) received water EX for 30 min daily; group (III) was intraperitoneally injected with TQ (5 mg/kg daily, for 21 days); group (IV) was intraperitoneally administered MC (10 μg/kg daily, for 14 days) and acted as the positive toxic control; group (V) was treated with MC and water EX; group (VI) was injected with MC and TQ; finally, group (VII) was treated with MC with TQ and water EX. In comparison with the control group, the results showed hepatic, renal, and cardiac toxicity in the MCLR-treated group, indicated by a significant increase (p < 0.05) in serum levels of alkaline phosphatase (ALP), aspartate aminotransferase (AST), alanine transferase (ALT), cholesterol, lactate dehydrogenase (LDH), creatine kinase (CK), creatine kinase-myocardial band (CK-MB), urea, creatinine, interleukin-6, interleukin -1β, and tumor necrosis factor-α levels. In addition, there were significant elevations (p < 0.05) in malondialdehyde (MDA) and nitric oxide (NO) levels and a significant decrease in reduced glutathione (GSH), glutathione peroxidase (GPx), catalase (CAT), and superoxide dismutase (SOD) in hepatic, cardiac, and renal tissues. Treatment with either TQ or water EX significantly improved (p < 0.05) the MC-induced toxicity with superiority of the TQ group in the restoration of normal ranges; however, cotreatment with both TQ and swimming EX showed the most improvement and restoration to normal ranges as a result of increasing EX clinical efficacy by TQ.
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Zhang X, Liang S, Gao X, Huang H, Lao F, Dai X. Protective Effect of Chitosan Oligosaccharide against Hydrogen Peroxide-Mediated Oxidative Damage and Cell Apoptosis via Activating Nrf2/ARE Signaling Pathway. Neurotox Res 2021; 39:1708-1720. [PMID: 34622385 DOI: 10.1007/s12640-021-00419-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 09/07/2021] [Accepted: 09/17/2021] [Indexed: 12/11/2022]
Abstract
Chitosan oligosaccharide (COS), hydrolyzed and deacetylated from chitosan, has been reported to possess varieties of biological activities. Alzheimer's disease (AD) is a multifactorial progressive neurodegenerative disorder characterized by cognitive decline and memory loss, where oxidative stress was reported to be an overwhelming cause of the occurrence of AD. We have previously reported that COS could significantly decrease cell death, ROS generation, and lipid peroxidation, though the potential mechanism was yet to be determined. This study was designed to investigate the neuroprotective effect of COS against hydrogen peroxide (H2O2)-induced oxidative stress and apoptosis in neuronal SH-SY5Y cells. Our results indicated that COS could dose-dependently scavenge H2O2 in the cell-free systems. Accordingly, COS markedly decreased H2O2-induced cell apoptosis and intracellular ROS generation, while increased antioxidant capacity in SH-SY5Y cells. Further, COS significantly reduced the expression of Bax and upregulated Bcl-2. The mRNA and protein expression levels of nuclear Nrf2, heme oxygenase 1 (HO-1), and NAD(P)H: quinone oxidoreductase 1 (NQO1) were significantly increased upon COS treatment. Moreover, Nrf2-siRNA evidently reversed the promotive effect of COS on expression levels of HO-1 and NQO1, and ARE-driven transcriptional activity as determined by double-luciferase reporter gene assay. Besides, COS reversed H2O2-mediated increased phosphorylation of ERK1/2 and p38 MAPK. In conclusion, our findings indicate that COS could protect SH-SY5Y cells from oxidative damage and apoptosis via regulating Nrf2/ARE signaling pathway, which may provide new applications for the prevention and treatment of AD.
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Affiliation(s)
- Xiaoxia Zhang
- Beijing Key Laboratory of Bioactive Substances and Functional Food, Beijing Union University, Beijing, 100191, China
| | - Shuang Liang
- Beijing Key Laboratory of Bioactive Substances and Functional Food, Beijing Union University, Beijing, 100191, China
| | - Xiaohan Gao
- Beijing Key Laboratory of Bioactive Substances and Functional Food, Beijing Union University, Beijing, 100191, China
| | - Hanchang Huang
- Beijing Key Laboratory of Bioactive Substances and Functional Food, Beijing Union University, Beijing, 100191, China
| | - Fengxue Lao
- Beijing Key Laboratory of Bioactive Substances and Functional Food, Beijing Union University, Beijing, 100191, China
| | - Xueling Dai
- Beijing Key Laboratory of Bioactive Substances and Functional Food, Beijing Union University, Beijing, 100191, China.
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Arman T, Clarke JD. Microcystin Toxicokinetics, Molecular Toxicology, and Pathophysiology in Preclinical Rodent Models and Humans. Toxins (Basel) 2021; 13:toxins13080537. [PMID: 34437407 PMCID: PMC8402503 DOI: 10.3390/toxins13080537] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2021] [Revised: 07/23/2021] [Accepted: 07/27/2021] [Indexed: 02/06/2023] Open
Abstract
Microcystins are ubiquitous toxins produced by photoautotrophic cyanobacteria. Human exposures to microcystins occur through the consumption of contaminated drinking water, fish and shellfish, vegetables, and algal dietary supplements and through recreational activities. Microcystin-leucine-arginine (MCLR) is the prototypical microcystin because it is reported to be the most common and toxic variant and is the only microcystin with an established tolerable daily intake of 0.04 µg/kg. Microcystin toxicokinetics is characterized by low intestinal absorption, rapid and specific distribution to the liver, moderate metabolism to glutathione and cysteinyl conjugates, and low urinary and fecal excretion. Molecular toxicology involves covalent binding to and inhibition of protein phosphatases, oxidative stress, cell death (autophagy, apoptosis, necrosis), and cytoskeleton disruption. These molecular and cellular effects are interconnected and are commonly observed together. The main target organs for microcystin toxicity are the intestine, liver, and kidney. Preclinical data indicate microcystins may also have nervous, pulmonary, cardiac, and reproductive system toxicities. Recent evidence suggests that exposure to other hepatotoxic insults could potentiate microcystin toxicity and increase the risk for chronic diseases. This review summarizes the current knowledge for microcystin toxicokinetics, molecular toxicology, and pathophysiology in preclinical rodent models and humans. More research is needed to better understand human toxicokinetics and how multifactorial exposures contribute to disease pathogenesis and progression.
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Zhang Y, Zhu P, Wu X, Yuan T, Su Z, Chen S, Zhou Y, Tao WA. Microcystin-LR Induces NLRP3 Inflammasome Activation via FOXO1 Phosphorylation, Resulting in Interleukin-1β Secretion and Pyroptosis in Hepatocytes. Toxicol Sci 2021; 179:53-69. [PMID: 33078829 DOI: 10.1093/toxsci/kfaa159] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Microcystin-LR (MC-LR), the most common and toxic microcystin (MC) present in freshwater, poses a substantial threat to human health, especially hepatotoxicity. Recent evidence reveals that the NLRP3 inflammasome plays an important role in liver injury by activating caspase-1 to promote interleukin-1β (IL-1β) secretion. In this study, we investigated the possible role of NLRP3 inflammasome activation in MC-LR-induced mouse liver inflammatory injury. We found that MC-LR administered to mice by oral gavage mainly accumulated in liver and induced the activation of the NLRP3 inflammasome and production of mature IL-1β. Additionally, we observed an increase in the levels of NLRP3 inflammasome-related proteins and the proportion of pyroptosis in MC-LR-treated AML-12 cells. We also found that inhibition of NLRP3 in mice attenuated MC-LR-induced IL-1β production, indicating an essential role for NLRP3 in MC-LR-induced liver inflammatory injury. In addition, we found that inhibition of FOXO1 by AKT-mediated hyperphosphorylation, due to protein phosphatase 2A (PP2A) inhibition, is required for MC-LR-induced expression of NLRP3. Taken together, our in vivo and in vitro findings suggest a model in which the NLRP3 inflammasome activation, a result of AKT-mediated hyperphosphorylation of FOXO1 through inhibition of PP2A, plays a key role in MC-LR-induced liver inflammatory injury via IL-1β secretion and pyroptotic cell death.
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Affiliation(s)
- Yali Zhang
- Department of Biochemistry and Molecular Biology, School of Medicine, Nantong University, Nantong, Jiangsu 226001, China
| | - Peipei Zhu
- Department of Biochemistry, Purdue University, West Lafayette, Indiana 47907
| | - Xiaofeng Wu
- Department of Biochemistry, Purdue University, West Lafayette, Indiana 47907
| | - Tianli Yuan
- Department of Biochemistry and Molecular Biology, School of Medicine, Nantong University, Nantong, Jiangsu 226001, China
| | - Zhangyao Su
- Department of Biochemistry and Molecular Biology, School of Medicine, Nantong University, Nantong, Jiangsu 226001, China
| | - Shiyin Chen
- Department of Biochemistry and Molecular Biology, School of Medicine, Nantong University, Nantong, Jiangsu 226001, China
| | - Yajun Zhou
- Department of Biochemistry and Molecular Biology, School of Medicine, Nantong University, Nantong, Jiangsu 226001, China
| | - Weiguo Andy Tao
- Department of Biochemistry, Purdue University, West Lafayette, Indiana 47907
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Huang P, Chen K, Ma T, Cao N, Weng D, Xu C, Xu L. The effects of short-term treatment of microcystin-LR on the insulin pathway in both the HL7702 cell line and livers of mice. ENVIRONMENTAL TOXICOLOGY 2020; 35:727-737. [PMID: 32073747 DOI: 10.1002/tox.22907] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Revised: 12/07/2019] [Accepted: 01/17/2020] [Indexed: 06/10/2023]
Abstract
Our previous work indicated exposure of Human liver cell 7702 (HL7702) cells to Microcystin-leucine-arginine (MC-LR) for 24 hours can disrupt insulin (INS) signaling by the hyperphosphorylation of specific proteins. For further exploring the time-dependent effect posed by MC-LR on this pathway, in the current study, HL7702 cells together with mice were exposed to the MC-LR with different concentrations under short-term treatment, and then, protein phosphatase 2A (PP2A) activity and expression of proteins related to INS signaling, as well as the characteristics of their action in the liver, were investigated. The results indicated, in HL7702 cells with 0.5, 1, and 6 hours of treatment by MC-LR, PP2A activity showed an obvious decrease in a time and concentration-dependent manner. While the total protein level of Akt, glycogen synthase kinase 3 (GSK-3), and glycogen synthase remained unchanged, GSK-3 and Akt phosphorylation increased significantly. In livers of mice with 1 hour of intraperitoneal injection with MC-LR, a similar change in these proteins was observed. In addition, the levels of total IRS1 and p-IRS1 at serine sites showed decreasing and increasing trends,respectively, and the hematoxylin and eosin staining showed that liver tissues of mice in the maximum-dose group exhibited obvious hepatocyte degeneration and hemorrhage. Our results further proved that short-term treatment with MC-LR can inhibit PP2A activity and disrupt INS signaling proteins' phosphorylation level, thereby interfering with the INS pathway. Our findings provide a helpful understanding of the toxic effects posed by MC-LR on the glucose metabolism of liver via interference with the INS signaling pathway.
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Affiliation(s)
- Pu Huang
- Department of Biochemistry, School of Medicine, Zhejiang University, Hangzhou, China
| | - Kele Chen
- Department of Biochemistry, School of Medicine, Zhejiang University, Hangzhou, China
| | - Tianfeng Ma
- Department I of Clinical Medicine, First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Naifang Cao
- Department I of Clinical Medicine, First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Dengpo Weng
- Department of Biochemistry, School of Medicine, Zhejiang University, Hangzhou, China
| | - Chun Xu
- Department of Endocrinology, The Third Medical Center of Chinese PLA General Hospital, Beijing, China
| | - Lihong Xu
- Department of Biochemistry, School of Medicine, Zhejiang University, Hangzhou, China
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Zhong S, Liu Y, Wang F, Wu Z, Zhao S. Microcystin-LR induced oxidative stress, inflammation, and apoptosis in alveolar type II epithelial cells of ICR mice in vitro. Toxicon 2019; 174:19-25. [PMID: 31874178 DOI: 10.1016/j.toxicon.2019.12.152] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2019] [Revised: 11/28/2019] [Accepted: 12/19/2019] [Indexed: 12/22/2022]
Abstract
Previous studies have shown that microcystin-LR (MC-LR) produced by toxic cyanobacterial blooms could inflict damage to the lung. However, the mechanisms underlying MC-induced pulmonary toxicity are not fully described. In this study, the primary' fetal alveolar type II epithelial cells (AEC II) from ICR mice, which are involved in formation of bioactive component of pulmonary epithelium and secretion of pulmonary surfactants, were exposed to MC-LR at different concentrations (0, 0.625, 1.25, 2.5, 5, 10, 20 μg/mL) for different time (12, 24, 36 h). Results showed that the viabilities of AEC II exposed to 10 and 20 μg MC-LR/mL were significantly decreased compared with the control group. Furthermore, MC-LR exposure resulted in overproduction of reactive oxygen species (ROS) and induced a significant reduction in superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px). Expressions of apoptosis-related proteins including bax, cyt-c, and caspase-9 were significantly up-regulated by exposure to 2.5, 5, 10, or 20 μg MC-LR/mL. When exposed to 5, 10, or 20 μg MC-LR/mL, expressions of proteins involved in inflammatory, p-65 and iNOS were significantly greater than those of the controls. In conclusion, inflammation and apoptosis might be responsible for MC-LR-induced pulmonary injury.
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Affiliation(s)
- Shengzheng Zhong
- School of Public Health, Anhui Medical University, Hefei, 230032, China
| | - Ying Liu
- Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, 230031, China
| | - Fang Wang
- School of Public Health, Anhui Medical University, Hefei, 230032, China
| | - Zaiwei Wu
- School of Public Health, Anhui Medical University, Hefei, 230032, China
| | - Sujuan Zhao
- School of Public Health, Anhui Medical University, Hefei, 230032, China.
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10
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Liu W, Zhan C, Zhang T, Zhang X. Microcystin-LR influences the in vitro oocyte maturation of zebrafish by activating the MAPK pathway. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2019; 215:105261. [PMID: 31419757 DOI: 10.1016/j.aquatox.2019.105261] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Revised: 06/14/2019] [Accepted: 07/16/2019] [Indexed: 06/10/2023]
Abstract
Harmful cyanobacteria and their production of microcystins (MCs) exert significant toxicity on reproduction of fish, especially the process of oogenesis. Our previous studies demonstrated that MCs have negative impacts on the quantity and quality of mature oocytes in female zebrafish. However, the underlying mechanisms of MCs disrupting oocyte maturation (OM) have been rarely reported. In the present study, in vitro oocytes (immature) were separated from zebrafish and treated with 1, 10, 100 μg/L MC-LR. The serine/threonine protein phosphatase 2A (PP2A) activity was downregulated significantly in oocytes exposed to 10 and 100 μg/L MC-LR for both 2 and 4 h. The phosphorylation levels of mitogen-activated protein kinase (MAPK) were detected without noticeable change in all oocytes treated with MC-LR for 2 h, whereas the activated levels of MAPK subtypes (ERK, p38 and JNK) increased remarkably in the 100 μg/L MC-LR treatment of 4 h. In the oocytes exposed to 100 μg/L MC-LR for 4 h, germinal vesicle breakdown (GVBD) rates changed abnormally and maturation-promoting factor (MPF) activity increased significantly, in accordance with the upregulation of Cyclin B protein levels. Moreover, the MAPK inhibitors (10 μM) were applied to explore the role of MAPK subtypes during MC-LR influencing OM and results showed that ERK inhibitor U0126 and p38 inhibitor SB203580 mitigated the effects of 100 μg/L MC-LR-induced MAPK hyper-phosphorylation and elevated GVBD in the oocytes. In conclusion, the present study indicates that microcystins disrupt the meiotic maturation by the pathway of MC-PP2A-MAPK-OM due to the phosphorylation disorder in oocytes.
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Affiliation(s)
- Wanjing Liu
- College of Fisheries, Huazhong Agricultural University, Hubei Provincial Engineering Laboratory for Pond Aquaculture, Wuhan, 430070, China
| | - Chunhua Zhan
- College of Fisheries, Huazhong Agricultural University, Hubei Provincial Engineering Laboratory for Pond Aquaculture, Wuhan, 430070, China
| | - Tongzhou Zhang
- College of Fisheries, Huazhong Agricultural University, Hubei Provincial Engineering Laboratory for Pond Aquaculture, Wuhan, 430070, China
| | - Xuezhen Zhang
- College of Fisheries, Huazhong Agricultural University, Hubei Provincial Engineering Laboratory for Pond Aquaculture, Wuhan, 430070, China.
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11
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Wang J, Chen Y, Zhang C, Xiang Z, Ding J, Han X. Learning and memory deficits and alzheimer's disease-like changes in mice after chronic exposure to microcystin-LR. JOURNAL OF HAZARDOUS MATERIALS 2019; 373:504-518. [PMID: 30947040 DOI: 10.1016/j.jhazmat.2019.03.106] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2018] [Revised: 03/18/2019] [Accepted: 03/23/2019] [Indexed: 06/09/2023]
Abstract
Previous studies have demonstrated that toxins produced by toxic cyanobacterial blooms are hazardous materials. Although microcystin-LR (MC-LR) has been revealed to inflict damage to the brain, the mechanisms underlying its neurotoxicity as a result of chronic exposure to MC-LR are not fully described. In this study, the mice were exposed to MC-LR dissolved in drinking water at doses of 1, 7.5, 15, or 30 μg/L for 180 days. MC-LR accumulated mostly in the mouse hippocampus (55 ng/g dry weight) followed by cortex (28 ng/g dry weight) after exposure to MC-LR at 30 μg/L. MC-LR exposure at this concentration induced dysfunction of learning and memory, accompanied with apoptosis of neuronal cells (with 10% reduction of the neurons in the CA1 region and 15% in the CA2 region), reduction of spine density, accumulation of β-amyloid plaques 1-42 (Aβ1-42), and enhanced phosphorylation of tau (p-tau) in the brain, which is characteristic of Alzheimer's disease (AD). These data indicate that MC-LR may induce AD-like pathology. Following prolonged exposure, MC-LR significantly upregulated the ratio of proBDNF to BDNF by downregulating the tPA levels, thereby activating downstream signaling pathways to improve the expression of p-JNK, and c-Jun while to inhibit the expression of p-Creb and p-PKC. This study uncovered new molecular mechanisms that account for neurotoxicity after chronic exposure to MC-LR, which has wide-ranging implications for public health.
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Affiliation(s)
- Jing Wang
- Immunology and Reproduction Biology Laboratory & State Key Laboratory of Analytical Chemistry for Life Science, Medical School, Nanjing University, Nanjing 210093, China; Jiangsu Key Laboratory of Molecular Medicine, Nanjing University, Nanjing 210093, China
| | - Yabing Chen
- Immunology and Reproduction Biology Laboratory & State Key Laboratory of Analytical Chemistry for Life Science, Medical School, Nanjing University, Nanjing 210093, China; Jiangsu Key Laboratory of Molecular Medicine, Nanjing University, Nanjing 210093, China
| | - Changliang Zhang
- Immunology and Reproduction Biology Laboratory & State Key Laboratory of Analytical Chemistry for Life Science, Medical School, Nanjing University, Nanjing 210093, China; Jiangsu Key Laboratory of Molecular Medicine, Nanjing University, Nanjing 210093, China
| | - Zou Xiang
- Department of Health Technology and Informatics, Faculty of Health and Social Sciences, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China
| | - Jie Ding
- Immunology and Reproduction Biology Laboratory & State Key Laboratory of Analytical Chemistry for Life Science, Medical School, Nanjing University, Nanjing 210093, China; Jiangsu Key Laboratory of Molecular Medicine, Nanjing University, Nanjing 210093, China.
| | - Xiaodong Han
- Immunology and Reproduction Biology Laboratory & State Key Laboratory of Analytical Chemistry for Life Science, Medical School, Nanjing University, Nanjing 210093, China; Jiangsu Key Laboratory of Molecular Medicine, Nanjing University, Nanjing 210093, China.
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12
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Lu X, Tian J, Wen H, Jiang M, Liu W, Wu F, Yu L, Zhong S. Microcystin-LR-regulated transcriptome dynamics in ZFL cells. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2019; 212:222-232. [PMID: 31136897 DOI: 10.1016/j.aquatox.2019.04.018] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Revised: 04/26/2019] [Accepted: 04/28/2019] [Indexed: 06/09/2023]
Abstract
Microcystin-LR (MC-LR) is a highly toxic hepatotoxin that poses great hazards to aquatic organisms and even human health. The zebrafish liver cell line (ZFL) is a valuable model for investigating toxicity and metabolism of toxicants. However, the toxicity of MC-LR and its effects on gene transcription of ZFL cells remains to be characterized. In this study, we determined the toxicity of MC-LR for ZFL cells and investigated the effects of MC-LR on cellular transcriptome dynamics. The EC50 of MC-LR for ZFL cells was 80.123 μg/mL. The ZFL cells were exposed to 10 μg/mL MC-LR for 0, 1, 3, 6, 12 or 24 h, and RNA-sequencing was performed to analyze gene transcription. A total of 10,209 genes were found to be regulated by MC-LR. The numbers of up- and down-regulated genes at different time points ranged from 2179 to 3202 and from 1501 to 2597, respectively. Furthermore, 1543 genes underwent differential splicing (AS) upon MC-LR exposure, of which 620 were not identified as differentially expressed gene (DEG). The effects of MC-LR on cellular functions were highly time-dependent. MAPK (mitogen-activated protein kinase) and FoxO (forkhead box O) signaling pathways were the most prominent pathways activated by MC-LR. Steroid biosynthesis and terpenoid backbone biosynthesis were the most enriched for the down-regulated genes. A gene regulatory network was constructed from the expression profile datasets and the candidate master transcription factors were identified. Our results shed light on the molecular mechanisms of MC-LR cellular toxicity and the transcriptome landscapes of ZFL cells upon MC-LR toxicity.
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Affiliation(s)
- Xing Lu
- Key Laboratory of Freshwater Biodiversity Conservation and Utilization of Ministry of Agriculture, Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Wuhan 430223, Hubei, China.
| | - Juan Tian
- Key Laboratory of Freshwater Biodiversity Conservation and Utilization of Ministry of Agriculture, Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Wuhan 430223, Hubei, China.
| | - Hua Wen
- Key Laboratory of Freshwater Biodiversity Conservation and Utilization of Ministry of Agriculture, Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Wuhan 430223, Hubei, China.
| | - Ming Jiang
- Key Laboratory of Freshwater Biodiversity Conservation and Utilization of Ministry of Agriculture, Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Wuhan 430223, Hubei, China.
| | - Wei Liu
- Key Laboratory of Freshwater Biodiversity Conservation and Utilization of Ministry of Agriculture, Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Wuhan 430223, Hubei, China.
| | - Fan Wu
- Key Laboratory of Freshwater Biodiversity Conservation and Utilization of Ministry of Agriculture, Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Wuhan 430223, Hubei, China.
| | - Lijuan Yu
- Key Laboratory of Freshwater Biodiversity Conservation and Utilization of Ministry of Agriculture, Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Wuhan 430223, Hubei, China.
| | - Shan Zhong
- Department of Genetics, Wuhan University, Wuhan 430071, Hubei, China; Hubei Provincial Key Laboratory of Developmentally Originated Disease, Wuhan 430071, Hubei, China; Hubei Province Key Laboratory of Allergy and Immunology, Wuhan 430071, Hubei, China.
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13
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Hinojosa MG, Gutiérrez-Praena D, Prieto AI, Guzmán-Guillén R, Jos A, Cameán AM. Neurotoxicity induced by microcystins and cylindrospermopsin: A review. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 668:547-565. [PMID: 30856566 DOI: 10.1016/j.scitotenv.2019.02.426] [Citation(s) in RCA: 69] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Revised: 02/25/2019] [Accepted: 02/27/2019] [Indexed: 05/26/2023]
Abstract
Microcystins (MCs) and cylindrospermopsin (CYN) are among the most frequent toxins produced by cyanobacteria. These toxic secondary metabolites are classified as hepatotoxins and cytotoxin, respectively. Furthermore, both may present the ability to induce damage to the nervous system. In this sense, there are many studies manifesting the potential of MCs to cause neurotoxicity both in vitro and in vivo, due to their probable capacity to cross the blood-brain-barrier through organic anion transporting polypeptides. Moreover, the presence of MCs has been detected in brain of several experimental models. Among the neurological effects, histopathological brain changes, deregulation of biochemical parameters in brain (production of oxidative stress and inhibition of protein phosphatases) and behavioral alterations have been described. It is noteworthy that minority variants such as MC-LF and -LW have demonstrated to exert higher neurotoxic effects compared to the most studied congener, MC-LR. By contrast, the available studies concerning CYN-neurotoxic effects are very scarce, mostly showing inflammation and apoptosis in neural murine cell lines, oxidative stress, and alteration of the acetylcholinesterase activity in vivo. However, more studies are required in order to clarify the neurotoxic potential of both toxins, as well as their possible contribution to neurodegenerative diseases.
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Affiliation(s)
- M G Hinojosa
- Area of Toxicology, Faculty of Pharmacy, Universidad de Sevilla, C/Profesor García González 2, 41012 Seville, Spain
| | - D Gutiérrez-Praena
- Area of Toxicology, Faculty of Pharmacy, Universidad de Sevilla, C/Profesor García González 2, 41012 Seville, Spain
| | - A I Prieto
- Area of Toxicology, Faculty of Pharmacy, Universidad de Sevilla, C/Profesor García González 2, 41012 Seville, Spain.
| | - R Guzmán-Guillén
- Area of Toxicology, Faculty of Pharmacy, Universidad de Sevilla, C/Profesor García González 2, 41012 Seville, Spain
| | - A Jos
- Area of Toxicology, Faculty of Pharmacy, Universidad de Sevilla, C/Profesor García González 2, 41012 Seville, Spain
| | - A M Cameán
- Area of Toxicology, Faculty of Pharmacy, Universidad de Sevilla, C/Profesor García González 2, 41012 Seville, Spain
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14
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Hinojosa MG, Prieto AI, Gutiérrez-Praena D, Moreno FJ, Cameán AM, Jos A. Neurotoxic assessment of Microcystin-LR, cylindrospermopsin and their combination on the human neuroblastoma SH-SY5Y cell line. CHEMOSPHERE 2019; 224:751-764. [PMID: 30851527 DOI: 10.1016/j.chemosphere.2019.02.173] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Revised: 02/12/2019] [Accepted: 02/24/2019] [Indexed: 06/09/2023]
Abstract
Microcystin-LR (MC-LR) and Cylindrospermopsin (CYN) are produced by cyanobacteria. Although being considered as a hepatotoxin and a cytotoxin, respectively, different studies have revealed neurotoxic properties for both of them. The aim of the present work was to study their cytotoxic effects, alone and in combination, in the SH-SY5Y cell line. In addition, toxicity mechanisms such as oxidative stress and acetylcholinesterase (AChE) activity, and morphological studies were carried out. Results showed a cytotoxic response of the cells after their exposure to 0-100 μg/mL of MC-LR or 0-10 μg/mL CYN in both differentiated and undifferentiated cells. Thus, CYN resulted to be more toxic than MC-LR. Respect to their combination, a higher cytotoxic effect than the toxins alone in the case of undifferentiated cells, and almost a similar response to the presented by MC-LR in differentiated cells were observed. However, after analyzing this data with the isobolograms method, an antagonistic effect was mainly obtained. The oxidative stress study only showed an affectation of glutathione levels at the highest concentrations assayed of MC-LR and the combination in the undifferentiated cells. A significant increase in the AChE activity was observed after exposure to MC-LR in undifferentiated cells, and after exposure to the combination of both cyanotoxins on differentiated cells. However, CYN decreased the AChE activity only on differentiated cultures. Finally, the morphological study revealed different signs of cellular affectation, with apoptotic processes at all the concentrations assayed. Therefore, both cyanotoxins isolated and in combination, have demonstrated to cause neurotoxic effects in the SH-SY5Y cell line.
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Affiliation(s)
- M G Hinojosa
- Área de Toxicología, Facultad de Farmacia, Universidad de Sevilla, C/Profesor García González 2, 41012, Sevilla, Spain
| | - A I Prieto
- Área de Toxicología, Facultad de Farmacia, Universidad de Sevilla, C/Profesor García González 2, 41012, Sevilla, Spain
| | - D Gutiérrez-Praena
- Área de Toxicología, Facultad de Farmacia, Universidad de Sevilla, C/Profesor García González 2, 41012, Sevilla, Spain.
| | - F J Moreno
- Área de Biología Celular, Facultad de Biología, Universidad de Sevilla, Avda. Reina Mercedes s/n, 41012, Sevilla, Spain
| | - A M Cameán
- Área de Toxicología, Facultad de Farmacia, Universidad de Sevilla, C/Profesor García González 2, 41012, Sevilla, Spain
| | - A Jos
- Área de Toxicología, Facultad de Farmacia, Universidad de Sevilla, C/Profesor García González 2, 41012, Sevilla, Spain
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Shin EJ, Hwang YG, Pham DT, Lee JW, Lee YJ, Pyo D, Jeong JH, Lei XG, Kim HC. Glutathione peroxidase-1 overexpressing transgenic mice are protected from neurotoxicity induced by microcystin-leucine-arginine. ENVIRONMENTAL TOXICOLOGY 2018; 33:1019-1028. [PMID: 30076769 DOI: 10.1002/tox.22580] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Revised: 05/15/2018] [Accepted: 05/20/2018] [Indexed: 06/08/2023]
Abstract
Although it has been well-recognized that microcystin-leucine-arginine (MCLR), the most common form of microcystins, induces neurotoxicity, little is currently known about the underlying mechanism for this neurotoxicity. Here, we found that MCLR (10 ng/μL/mouse, i.c.v.) induces significant neuronal loss in the hippocampus of mice. MCLR-induced neurotoxicity was accompanied by oxidative stress, as shown by a significant increase in the level of 4-hydroxynonenal, protein carbonyl, and reactive oxygen species (ROS). Superoxide dismutase-1 (SOD-1) activity was significantly increased, but glutathione peroxidase (GPx) level was significantly decreased following MCLR insult. In addition, MCLR significantly inhibited GSH/GSSG ratio, and significantly induced NFκB DNA binding activity. Because reduced activity of GPx appeared to be critical for the imbalance between activities of SODs and GPx, we utilized GPx-1 overexpressing transgenic mice to ascertain the role of GPx-1 in this neurotoxicity. Genetic overexpression of GPx-1 or NFκB inhibitor pyrrolidine dithiocarbamate (PDTC) significantly attenuated MCLR-induced hippocampal neuronal loss in mice. However, PDTC did not exert any additive effect on neuroprotection mediated by GPx-1 overexpression, indicating that NFκB is a neurotoxic target of MCLR. Combined, these results suggest that MCLR-induced neurotoxicity requires oxidative stress associated with failure in compensatory induction of GPx, possibly through activation of the transcription factor NFκB.
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Affiliation(s)
- Eun-Joo Shin
- Neuropsychopharmacology and Toxicology Program, College of Pharmacy, Kangwon National University, Republic of Korea
| | - Yeong Gwang Hwang
- Neuropsychopharmacology and Toxicology Program, College of Pharmacy, Kangwon National University, Republic of Korea
| | - Duc Toan Pham
- Neuropsychopharmacology and Toxicology Program, College of Pharmacy, Kangwon National University, Republic of Korea
| | - Ji Won Lee
- Neuropsychopharmacology and Toxicology Program, College of Pharmacy, Kangwon National University, Republic of Korea
| | - Yu Jeung Lee
- Clinical Pharmacy, College of Pharmacy, Kangwon National University, Republic of Korea
| | - Dongjin Pyo
- Department of Chemistry, College of Natural Sciences, Kangwon National University, Republic of Korea
| | - Ji Hoon Jeong
- Department of Pharmacology, College of Medicine, Chung-Ang University, Seoul, Republic of Korea
| | - Xin Gen Lei
- Department of Animal Science, Cornell University, New York
| | - Hyoung-Chun Kim
- Neuropsychopharmacology and Toxicology Program, College of Pharmacy, Kangwon National University, Republic of Korea
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Melone MAB, Dato C, Paladino S, Coppola C, Trebini C, Giordana MT, Perrone L. Verapamil Inhibits Ser202/Thr205 Phosphorylation of Tau by Blocking TXNIP/ROS/p38 MAPK Pathway. Pharm Res 2018; 35:44. [DOI: 10.1007/s11095-017-2276-2] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Accepted: 10/05/2017] [Indexed: 12/19/2022]
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17
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Liu J, Xu C, Zhang S, Li H, Chen K, Huang P, Guo Z, Xu L. Microcystin-LR disrupts insulin signaling by hyperphosphorylating insulin receptor substrate 1 and glycogen synthase. ENVIRONMENTAL TOXICOLOGY 2018; 33:16-22. [PMID: 28984034 DOI: 10.1002/tox.22456] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2017] [Revised: 07/21/2017] [Accepted: 07/27/2017] [Indexed: 06/07/2023]
Abstract
Microcystin-LR (MC-LR) is a cyanobacteria-derived heptapeptide that has been commonly characterized as a hepatotoxin. Although the liver is a primary organ in glucose homeostasis, the effect of MC-LR on glucose metabolism remains unclear. In this study, the human liver cell line HL7702 and ICR mice were exposed to various concentrations of MC-LR for 24 h, and the proteins involved in insulin signaling were investigated. The results showed that MC-LR treatment induced the hyperphosphorylation of insulin receptor substrate 1 (IRS1) at several serine sites, S307, S323, S636/639, and S1101 in HL7702 cells, and S302, S318, S632/635, and S1097 in mice livers. In addition, the activation of S6K1 was demonstrated to play an important role in MC-LR-induced IRS1 hyperphosphorylation at several serine sites. Decreased levels of total IRS1 were observed in the mice livers, but there was no significant change in HL7702 cells. MC-LR also induced glycogen synthase (GS) hyperphosphorylation at S641 (inactivating GS) both in vitro and in vivo, even glycogen synthase kinase 3, a well-known GS kinase, was inactivated after MC-LR treatment. Moreover, MC-LR could block insulin-induced GS activation. In addition, glucose transport in liver cells was not impacted by MC-LR either with or without insulin stimulation. Our study implies that MC-LR can interfere with the actions of IRS1 and GS in insulin signaling and may have a toxic effect on glucose metabolism in the liver.
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Affiliation(s)
- Jinghui Liu
- Department of Biochemistry, School of Medicine, Zhejiang University, Hangzhou, 310058, China
| | - Chun Xu
- Department of Endocrinology, General Hospital of the Chinese People's Armed Police Forces, Beijing, 100039, China
| | - Shaofeng Zhang
- Department of Endocrinology, General Hospital of the Chinese People's Armed Police Forces, Beijing, 100039, China
| | - Haoyan Li
- Department of Endocrinology, General Hospital of the Chinese People's Armed Police Forces, Beijing, 100039, China
| | - Kele Chen
- Department of Biochemistry, School of Medicine, Zhejiang University, Hangzhou, 310058, China
| | - Pu Huang
- Department of Biochemistry, School of Medicine, Zhejiang University, Hangzhou, 310058, China
| | - Zonglou Guo
- Department of Biosystem Engineering, College of Biosystem Engineering and Food Science, Zhejiang University, Hangzhou, 310058, China
| | - Lihong Xu
- Department of Biochemistry, School of Medicine, Zhejiang University, Hangzhou, 310058, China
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18
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Augusti PR, Brasil AVS, Souto C, Göethel G, de Oliveira Rios A, Emanuelli T, Bürger ME, Garcia SC. Microcystin-LR exposure induces oxidative damage in Caenorhabditis elegans: Protective effect of lutein extracted from marigold flowers. Food Chem Toxicol 2017; 109:60-67. [PMID: 28866331 DOI: 10.1016/j.fct.2017.08.045] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Revised: 08/28/2017] [Accepted: 08/29/2017] [Indexed: 12/31/2022]
Abstract
Microcystin-LR (MIC-LR) is a hepatotoxin, with toxicity mechanisms linked to oxidative stress. Besides, neurotoxic effects of MIC-LR have recently been described. Herein, we evaluated the effects of environmentally important concentrations of MIC-LR (1, 10, 100, 250, and 500 μg/L) on oxidative stress markers and the survival rate of the nematode Caenorhabditis elegans (C. elegans). In addition, a possible protective effect of the carotenoid lutein (LUT) extracted from marigold flowers against MIC-LR toxicity was investigated. Higher concentrations (250 and 500 μg/L) of MIC-LR induced the generation of reactive oxygen species (ROS) and resulted in a survival loss in C elegans. Meanwhile, all MIC-LR concentrations caused an increase in the superoxide dismutase (SOD) expression, while catalase (CAT) expression was only affected at 500 μg/L. The carotenoid LUT prevented the ROS generation, impairment in the CAT expression, and the survival loss induced by MIC-LR in C. elegans. Our results confirm the toxicity of MIC-LR even in a liver-lacking invertebrate and the involvement of oxidative events in this response. Additionally, LUT appears to be able to mitigate the MIC-LR toxic effects.
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Affiliation(s)
- Paula Rossini Augusti
- Instituto de Ciência e Tecnologia de Alimentos, Universidade Federal do Rio Grande do Sul (UFRGS), Av. Bento Gonçalves, 9500, Prédio 43.212, Campus do Vale, Porto Alegre, CEP 91501-970, RS, Brazil.
| | - Allana Von Sulzback Brasil
- Instituto de Ciência e Tecnologia de Alimentos, Universidade Federal do Rio Grande do Sul (UFRGS), Av. Bento Gonçalves, 9500, Prédio 43.212, Campus do Vale, Porto Alegre, CEP 91501-970, RS, Brazil
| | - Caroline Souto
- Laboratório de Toxicologia (LATOX), Departamento de Análises, Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul (UFRGS), Av. Ipiranga, 2752, Porto Alegre, CEP 90610-000, RS, Brazil
| | - Gabriela Göethel
- Laboratório de Toxicologia (LATOX), Departamento de Análises, Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul (UFRGS), Av. Ipiranga, 2752, Porto Alegre, CEP 90610-000, RS, Brazil
| | - Alessandro de Oliveira Rios
- Instituto de Ciência e Tecnologia de Alimentos, Universidade Federal do Rio Grande do Sul (UFRGS), Av. Bento Gonçalves, 9500, Prédio 43.212, Campus do Vale, Porto Alegre, CEP 91501-970, RS, Brazil
| | - Tatiana Emanuelli
- Núcleo Integrado de Desenvolvimento em Análises Laboratoriais (NIDAL), Departamento de Tecnologia e Ciência dos Alimentos, Centro de Ciências Rurais, Universidade Federal de Santa Maria (UFSM), Av. Roraima, 1000, Santa Maria, CEP 97105-900, RS, Brazil
| | - Marilise Escobar Bürger
- Laboratório de Farmacologia e Toxicologia (FARMATOX), Departamento de Fisiologia, Centro de Ciências da Saúde, Universidade Federal de Santa Maria (UFSM), Av. Roraima, 1000, Santa Maria, CEP 97105-900, RS, Brazil
| | - Solange Cristina Garcia
- Laboratório de Toxicologia (LATOX), Departamento de Análises, Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul (UFRGS), Av. Ipiranga, 2752, Porto Alegre, CEP 90610-000, RS, Brazil
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Buratti FM, Manganelli M, Vichi S, Stefanelli M, Scardala S, Testai E, Funari E. Cyanotoxins: producing organisms, occurrence, toxicity, mechanism of action and human health toxicological risk evaluation. Arch Toxicol 2017; 91:1049-1130. [DOI: 10.1007/s00204-016-1913-6] [Citation(s) in RCA: 258] [Impact Index Per Article: 36.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Accepted: 12/13/2016] [Indexed: 12/11/2022]
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Zhao J, Tian F, Zhai Q, Yu R, Zhang H, Gu Z, Chen W. Protective effects of a cocktail of lactic acid bacteria on microcystin-LR-induced hepatotoxicity and oxidative damage in BALB/c mice. RSC Adv 2017. [DOI: 10.1039/c7ra03035e] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
The aim of this study was to investigate the effects of mixed lactic acid bacteria (LAB) against microcystin-LR-exposed hepatotoxicity and oxidative stress in BALB/c mice.
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Affiliation(s)
- Jichun Zhao
- State Key Laboratory of Food Science and Technology
- School of Food Science and Technology
- Jiangnan University
- Wuxi 214122
- P. R. China
| | - Fengwei Tian
- State Key Laboratory of Food Science and Technology
- School of Food Science and Technology
- Jiangnan University
- Wuxi 214122
- P. R. China
| | - Qixiao Zhai
- State Key Laboratory of Food Science and Technology
- School of Food Science and Technology
- Jiangnan University
- Wuxi 214122
- P. R. China
| | - Ruipeng Yu
- State Key Laboratory of Food Science and Technology
- School of Food Science and Technology
- Jiangnan University
- Wuxi 214122
- P. R. China
| | - Hao Zhang
- State Key Laboratory of Food Science and Technology
- School of Food Science and Technology
- Jiangnan University
- Wuxi 214122
- P. R. China
| | - Zhennan Gu
- State Key Laboratory of Food Science and Technology
- School of Food Science and Technology
- Jiangnan University
- Wuxi 214122
- P. R. China
| | - Wei Chen
- State Key Laboratory of Food Science and Technology
- School of Food Science and Technology
- Jiangnan University
- Wuxi 214122
- P. R. China
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Bulc Rozman K, Jurič DM, Šuput D. Selective cytotoxicity of microcystins LR, LW and LF in rat astrocytes. Toxicol Lett 2016; 265:1-8. [PMID: 27864109 DOI: 10.1016/j.toxlet.2016.11.008] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Revised: 11/08/2016] [Accepted: 11/14/2016] [Indexed: 12/24/2022]
Abstract
Microcystins (MCs) comprise a group of cyanobacterial toxins with hepatotoxic, nephrotoxic and, possibly, neurotoxic activity in mammals. In order to understand the development of their neurotoxicity we investigated the toxic effects of MC variants, MC-LR, MC-LW and MC-LF, in astrocytes that play a central role in maintaining brain homeostasis. 24h exposure of cultured rat cortical astrocytes to MCs revealed dose-dependent toxicity of MC-LF and MC-LW, but not of MC-LR, observed by significant reduction in cell number, declined viability monitored by MTT test and an increased percentage of apoptotic cells, confirmed by Annexin-V labelling. The cultured astrocytes expressed organic anion-transporting polypeptides (Oatp) Oatp1a4, Oatp1c1 and Oatp1a5, but not Oatp1b2. Intracellular localisation of MC-LF and MC-LW, proven by anti-Adda primary antibody, demonstrated transport of tested MCs into cultured astrocytes. Acute MC-LW and MC-LF intoxication induced cytoskeletal disruption as seen by the degradation of glial fibrillary acid protein (GFAP), actin and the tubulin network. In this in vitro study, MC-LF and MC-LW, but not MC-LR, are shown to cause the dysfunction of astrocytic homeostatic capabilities, already at low concentrations, suggesting that astrocyte atrophy, with loss of function, could be expected in the brain response to the toxic insult.
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Affiliation(s)
- Klara Bulc Rozman
- Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška cesta 4, Ljubljana, Slovenia.
| | - Damijana Mojca Jurič
- Institute of Pharmacology and Experimental Toxicology, Faculty of Medicine, University of Ljubljana, Korytkova 2, Ljubljana, Slovenia.
| | - Dušan Šuput
- Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška cesta 4, Ljubljana, Slovenia.
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22
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Qi M, Dang Y, Xu Q, Yu L, Liu C, Yuan Y, Wang J. Microcystin-LR induced developmental toxicity and apoptosis in zebrafish (Danio rerio) larvae by activation of ER stress response. CHEMOSPHERE 2016; 157:166-173. [PMID: 27219292 DOI: 10.1016/j.chemosphere.2016.05.038] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Revised: 05/12/2016] [Accepted: 05/12/2016] [Indexed: 06/05/2023]
Abstract
Recent studies have demonstrated that cyanobacteria-derived Microcystin-LR (MC-LR) can cause developmental toxicity and trigger apoptosis in zebrafish (Danio rerio) larvae, but the underlying mechanisms remain largely unknown. In this study, we tested the hypothesis that the mechanism by which MC-LR induces developmental toxicity is through activation of endoplasmic reticulum (ER) stress. MC-LR (4.0 μM) exposure through submersion caused serious developmental toxicity, such as malformation, growth delay and decreased heart rates in zebrafish larvae, which could be inhibited by ER stress blocker, tauroursodeoxycholic acid (TUDCA, 20 μM). Meanwhile, acridine orange (AO) staining showed TUDCA could rescue cell apoptosis in heart area in zebrafish larvae resulted by MC-LR exposure. Real-time polymerase chain reaction (real-time PCR) analysis demonstrated that MC-LR induced activation of ER stress which consequently triggered apoptosis in zebrafish larvae. Protein expression examined by western blot indicated that MC-LR could activate MAPK8/Bcl-2/Bax pathway and caspase-dependent apoptotic pathway in zebrafish larva and the effects were mitigated by inhibition of ER stress. Taken together, the results observed in this study suggested that ER stress plays a critical role in developmental toxicity and apoptosis in zebrafish embryos exposed to MC-LR.
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Affiliation(s)
- Mei Qi
- College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China
| | - Yao Dang
- College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China
| | - Qinglong Xu
- College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China
| | - Liqin Yu
- College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China; Hubei Provincial Engineering Laboratory for Pond Aquaculture, Wuhan 430070, China
| | - Chunsheng Liu
- College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China; Hubei Provincial Engineering Laboratory for Pond Aquaculture, Wuhan 430070, China; Collaborative Innovation Center for Efficient and Health Production of Fisheries in Hunan Province, Changde 415000, China
| | - Yongchao Yuan
- College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China
| | - Jianghua Wang
- College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China; Hubei Provincial Engineering Laboratory for Pond Aquaculture, Wuhan 430070, China.
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23
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Meng G, Chai K, Li X, Zhu Y, Huang W. Luteolin exerts pro-apoptotic effect and anti-migration effects on A549 lung adenocarcinoma cells through the activation of MEK/ERK signaling pathway. Chem Biol Interact 2016; 257:26-34. [PMID: 27474067 DOI: 10.1016/j.cbi.2016.07.028] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Revised: 07/03/2016] [Accepted: 07/24/2016] [Indexed: 11/17/2022]
Abstract
An increasing amount of evidence suggests that luteolin, a common dietary flavonoid that is widely distributed in plants and foods, has been shown to be protective against cancer. However, the precise underlying mechanisms of its action against lung cancer are still poorly understood. In the present study, we investigated whether luteolin exhibits the anti-cancer effect in lung cancer through the induction of cell apoptosis and inhibition of cell migration, and whether mitogen-activated protein kinases (MAPKs) and Akt signaling pathways are required. Results revealed that luteolin exerted an anti-proliferation effect in a dose- and time-dependent manner in A549 lung adenocarcinoma cells, and induced apoptosis with a concomitant increase in the activation of caspases-3 and -9, diminution of Bcl-2, elevation in Bax expression, and the phosphorylation of MEK and its down-stream kinase ERK, as well as the activation of Akt. Luteolin also dramatically inhibited cell motility and migration in A549 cells. The inhibitor of MEK-ERK pathway protected against luteolin-induced cell death and suppressed the apoptosis-inducing and anti-migratory effects of luteolin, suggesting MEK-ERK signaling pathway plays an important role in mediating the pro-apoptotic effect and anti-migration effects of luteolin. Taken together, this study provides a new insight into the mode of action of luteolin on lung cancer.
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Affiliation(s)
- Guanmin Meng
- Department of Clinical Laboratory, Tongde Hospital of Zhejiang Province, Hangzhou, China; Department of Biochemistry, University of Alberta, Edmonton, Alberta, Canada
| | - Kequn Chai
- Department of Oncology, Tongde Hospital of Zhejiang Province, Hangzhou, China
| | - Xinda Li
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta, Canada
| | - Yongqiang Zhu
- Zhejiang Academy of Traditional Chinese Medicine, Tongde Hospital of Zhejiang Province, Hangzhou, China
| | - Weihua Huang
- Zhejiang Academy of Traditional Chinese Medicine, Tongde Hospital of Zhejiang Province, Hangzhou, China.
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24
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Li X, Xu L, Zhou W, Zhao Q, Wang Y. Chronic exposure to microcystin-LR affected mitochondrial DNA maintenance and caused pathological changes of lung tissue in mice. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2016; 210:48-56. [PMID: 26706032 DOI: 10.1016/j.envpol.2015.12.001] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Revised: 11/11/2015] [Accepted: 12/01/2015] [Indexed: 06/05/2023]
Abstract
Microcystin-LR (MC-LR), an important variant of cyanotoxin family, was frequently encountered in the contaminated aquatic environment and taken as a potent hepatotoxin. However, a little was known on the association between the long-term MC-LR exposure and lung damage. In this study, we investigated the changes of the pulmonary histopathology, mitochondrial DNA (mtDNA) integrity and the expression of mtDNA encoded genes in the mice with chronic exposed to MC-LR at different concentrations (1, 5, 10, 20 and 40 μg/L) for 12 months. Our results showed that the long-term and persistent exposure to MC-LR disturbed the balance of redox system, influenced mtDNA stability, changed the expression of mitochondrial genes in the lung cells. Notably, MC-LR exposure influenced the level of inflammatory cytokines and resulted in thickening of the alveolar septa. In conclusion, chronic exposure to MC-LR affected mtDNA maintenance, and caused lung impairment in mice.
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Affiliation(s)
- Xinxiu Li
- Department of Medical Genetics, Nanjing University School of Medicine, Nanjing, 210093, China; Jiangsu Key Laboratory of Molecular Medicine, Nanjing University School of Medicine, Nanjing, 210093, China
| | - Lizhi Xu
- Department of Medical Genetics, Nanjing University School of Medicine, Nanjing, 210093, China; Jiangsu Key Laboratory of Molecular Medicine, Nanjing University School of Medicine, Nanjing, 210093, China
| | - Wei Zhou
- Department of Medical Genetics, Nanjing University School of Medicine, Nanjing, 210093, China; Jiangsu Key Laboratory of Molecular Medicine, Nanjing University School of Medicine, Nanjing, 210093, China
| | - Qingya Zhao
- Department of Medical Genetics, Nanjing University School of Medicine, Nanjing, 210093, China; Jiangsu Key Laboratory of Molecular Medicine, Nanjing University School of Medicine, Nanjing, 210093, China
| | - Yaping Wang
- Department of Medical Genetics, Nanjing University School of Medicine, Nanjing, 210093, China; Jiangsu Key Laboratory of Molecular Medicine, Nanjing University School of Medicine, Nanjing, 210093, China.
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25
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Chen L, Chen J, Zhang X, Xie P. A review of reproductive toxicity of microcystins. JOURNAL OF HAZARDOUS MATERIALS 2016; 301:381-99. [PMID: 26521084 DOI: 10.1016/j.jhazmat.2015.08.041] [Citation(s) in RCA: 233] [Impact Index Per Article: 29.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2015] [Revised: 08/20/2015] [Accepted: 08/23/2015] [Indexed: 05/25/2023]
Abstract
Animal studies provide strong evidence of positive associations between microcystins (MCs) exposure and reproductive toxicity, representing a threat to human reproductive health and the biodiversity of wild life. This paper reviews current knowledge of the reproductive toxicity of MCs, with regard to mammals, fishes, amphibians, and birds, mostly in males. Toxicity of MCs is primarily governed by the inhibition of protein phosphatases 1 and 2A (PP1 and PP2A) and disturbance of cellular phosphorylation balance. MCs exposure is related to excessive production of reactive oxygen species (ROS) and oxidative stress, leading to cytoskeleton disruption, mitochondria dysfunction, endoplasmic reticulum (ER) stress, and DNA damage. MCs induce cell apoptosis mediated by the mitochondrial and ROS and ER pathways. Through PP1/2A inhibition and oxidative stress, MCs lead to differential expression/activity of transcriptional factors and proteins involved in the pathways of cellular differentiation, proliferation, and tumor promotion. MC-induced DNA damage is also involved in carcinogenicity. Apart from a direct effect on testes and ovaries, MCs indirectly affect sex hormones by damaging the hypothalamic-pituitary-gonad (HPG) axis and liver. Parental exposure to MCs may result in hepatotoxicity and neurotoxicity of offspring. We also summarize the current research gaps which should be addressed by further studies.
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Affiliation(s)
- Liang Chen
- Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Jun Chen
- Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China.
| | - Xuezhen Zhang
- College of Fisheries, Huazhong Agricultural University, Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan 430070, China.
| | - Ping Xie
- Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China.
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26
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Cai F, Liu J, Li C, Wang J. Critical Role of Endoplasmic Reticulum Stress in Cognitive Impairment Induced by Microcystin-LR. Int J Mol Sci 2015; 16:28077-86. [PMID: 26602924 PMCID: PMC4691030 DOI: 10.3390/ijms161226083] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Revised: 11/16/2015] [Accepted: 11/17/2015] [Indexed: 01/11/2023] Open
Abstract
Recent studies showed that cyanobacteria-derived microcystin-leucine-arginine (MCLR) can cause hippocampal pathological damage and trigger cognitive impairment; but the underlying mechanisms have not been well understood. The objective of the present study was to investigate the mechanism of MCLR-induced cognitive deficit; with a focus on endoplasmic reticulum (ER) stress. The Morris water maze test and electrophysiological study demonstrated that MCLR caused spatial memory injury in male Wistar rats; which could be inhibited by ER stress blocker; tauroursodeoxycholic acid (TUDCA). Meanwhile; real-time polymerase chain reaction (real-time PCR) and immunohistochemistry demonstrated that the expression level of the 78-kDa glucose-regulated protein (GRP78); C/EBP homologous protein (CHOP) and caspase 12 were significantly up-regulated. These effects were rescued by co-administration of TUDCA. In agreement with this; we also observed that treatment of rats with TUDCA blocked the alterations in ER ultrastructure and apoptotic cell death in CA1 neurons from rats exposed to MCLR. Taken together; the present results suggested that ER stress plays an important role in potential memory impairments in rats treated with MCLR; and amelioration of ER stress may serve as a novel strategy to alleviate damaged cognitive function triggered by MCLR.
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Affiliation(s)
- Fei Cai
- Department of Pharmacology, Hubei University of Science and Technology, Xianning 437100, China.
| | - Jue Liu
- Department of Pharmacy, The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430014, China.
| | - Cairong Li
- Hubei Province Key Laboratory on Cardiovascular, Cerebrovascular, and Metabolic Disorders, Hubei University of Science and Technology, Xianning 437100, China.
| | - Jianghua Wang
- Fisheries College, Huazhong Agricultural University, Wuhan 430070, China.
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27
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Mechanisms of microcystin-LR-induced cytoskeletal disruption in animal cells. Toxicon 2015; 101:92-100. [DOI: 10.1016/j.toxicon.2015.05.005] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2015] [Revised: 05/06/2015] [Accepted: 05/12/2015] [Indexed: 12/31/2022]
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28
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Li X, Zhao Q, Zhou W, Xu L, Wang Y. Effects of chronic exposure to microcystin-LR on hepatocyte mitochondrial DNA replication in mice. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:4665-4672. [PMID: 25723732 DOI: 10.1021/es5059132] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Microcystins (MCs) are produced by cyanobacterial blooms, and microcystin-LR (MC-LR) is the most toxic among the 80 MC variants. Data have shown that the liver is one of the specific target organs for MC-LR, which can cause mitochondrial DNA (mtDNA) damage, resulting in mitochondrial dysfunction. However, the underlying mechanism is still unclear. In the present study, we evaluated the genetic toxicity of MC-LR in mice drinking water at different concentrations (1, 5, 10, 20, and 40 μg/L) for 12 months. Our results showed that long-term and persistent exposure to MC-LR increased the 8-hydroxy-2'-deoxyguanosine (8-OHdG) levels of DNA in liver cells, damaged the integrity of mtDNA and nuclear DNA (nDNA), and altered the mtDNA content. Notably, MC-LR exposure can change the expression of mitochondrial genes and nuclear genes that are critical for regulating mtDNA replication and repairing oxidized DNA. They also further impaired the function of mitochondria and liver cells.
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Affiliation(s)
- Xinxiu Li
- †Department of Medical Genetics, and ‡Jiangsu Key Laboratory of Molecular Medicine, Nanjing University School of Medicine, Nanjing, Jiangsu 210093, People's Republic of China
| | - Qingya Zhao
- †Department of Medical Genetics, and ‡Jiangsu Key Laboratory of Molecular Medicine, Nanjing University School of Medicine, Nanjing, Jiangsu 210093, People's Republic of China
| | - Wei Zhou
- †Department of Medical Genetics, and ‡Jiangsu Key Laboratory of Molecular Medicine, Nanjing University School of Medicine, Nanjing, Jiangsu 210093, People's Republic of China
| | - Lizhi Xu
- †Department of Medical Genetics, and ‡Jiangsu Key Laboratory of Molecular Medicine, Nanjing University School of Medicine, Nanjing, Jiangsu 210093, People's Republic of China
| | - Yaping Wang
- †Department of Medical Genetics, and ‡Jiangsu Key Laboratory of Molecular Medicine, Nanjing University School of Medicine, Nanjing, Jiangsu 210093, People's Republic of China
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29
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Li XB, Zhang X, Ju J, Li Y, Yin L, Pu Y. Alterations in neurobehaviors and inflammation in hippocampus of rats induced by oral administration of microcystin-LR. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2014; 21:12419-12425. [PMID: 24938810 DOI: 10.1007/s11356-014-3151-x] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2014] [Accepted: 06/03/2014] [Indexed: 06/03/2023]
Abstract
Microcystin-LR (MC-LR) is a widely studied toxic peptide secreted by certain water blooms of cyanobacteria that exhibit hepatotoxicity and neural toxicity. This study aimed to observe the neurotoxic effects of low-dose MC-LR exposure by oral administration. Male Sprague-Dawley (SD) rats were administered orally every 2 days for 8 weeks with pure water and 0.2, 1.0, and 5.0 μg/kg MC-LR. The Morris water maze test was used to assess the spatial learning and memory capability of rats. The activation of astrocytes and nitric oxide synthase (NOS) was evaluated by immunohistochemistry, and concentrations of nitric oxide (NO) in rat hippocampus were analyzed. Slight liver dysfunction was observed in the 5.0 μg/kg MC-LR-treated rats. Impairment of spatial learning and memory was also observed in the 5.0 μg/kg MC-LR-treated rats. Astrocytes in the hippocampus of the 5.0 μg/kg MC-LR-treated rats showed enhanced activation and cell density; the inflammatory indicators, NOS and NO, increased in accordance with astrocyte activation. This study showed that oral exposure of MC-LR had adverse affects on neurobehaviors, and induced inflammation in memory-related brain regions.
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Affiliation(s)
- Xiao-Bo Li
- Key Laboratory of Environmental Medicine Engineering, Ministry of Education, School of Public Health, Southeast University, Dingjiaqiao 87, Nanjing, 210009, China,
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