1
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Abdallah MF, Recote JM, Van Camp C, Van Hassel WHR, Pedroni L, Dellafiora L, Masquelier J, Rajkovic A. Potential (co-)contamination of dairy milk with AFM1 and MC-LR and their synergistic interaction in inducing mitochondrial dysfunction in HepG2 cells. Food Chem Toxicol 2024; 192:114907. [PMID: 39111684 DOI: 10.1016/j.fct.2024.114907] [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: 06/07/2024] [Revised: 07/23/2024] [Accepted: 08/03/2024] [Indexed: 08/11/2024]
Abstract
Several toxic metabolites, such as aflatoxin M1 (AFM1), are known to contaminate dairy milk. However, as mentioned in an external EFSA report, there is a knowledge gap regarding the carry-over of certain emerging toxins such as microcystin-LR (MC-LR). Therefore, this work aimed to develop an LC-MS/MS method for MC-LR quantification in dairy milk. Also, the method included AFM1 as a common fungal metabolite and applied to analyze 113 dairy milk samples collected directly after the end of the summer peak. Both toxins were below their LODs, keeping the question on MC-LR carry-over still unanswered. Moreover, an in silico analysis, using a 3D molecular modeling was performed, pointing to a possible interaction between MC-LR and milk proteins, especially β-lactoglobulin. Since AFM1 and MC-LR are hepatotoxic, their interaction in inducing mitochondrial dysfunction in HepG2 cells was investigated at low (subcytotoxic) concentrations. Live cell imaging-based assays showed an inhibition in cell viability, without involvement of caspase-3/7, and a hyperpolarization in the mitochondrial membrane potential after the exposure to a mixture of 100 ng mL-1 AFM1 and 1000 ng mL-1 MC-LR for 48h. Extracellular flux analysis revealed inhibitions of several key parameters of mitochondrial function (basal respiration, ATP-linked respiration, and spare respiratory capacity).
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Affiliation(s)
- Mohamed F Abdallah
- Department of Food Technology, Safety and Health, Faculty of Bioscience Engineering, Ghent University, Belgium; Department of Forensic Medicine and Toxicology, Faculty of Veterinary Medicine, Assiut University, Egypt.
| | - Jessa May Recote
- Department of Food Technology, Safety and Health, Faculty of Bioscience Engineering, Ghent University, Belgium
| | - Camille Van Camp
- Unit Toxins, Organic Contaminants and Additives, Sciensano, Belgium
| | | | | | | | | | - Andreja Rajkovic
- Department of Food Technology, Safety and Health, Faculty of Bioscience Engineering, Ghent University, Belgium
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2
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Ge K, Du X, Liu H, Meng R, Wu C, Zhang Z, Liang X, Yang J, Zhang H. The cytotoxicity of microcystin-LR: ultrastructural and functional damage of cells. Arch Toxicol 2024; 98:663-687. [PMID: 38252150 DOI: 10.1007/s00204-023-03676-0] [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: 10/23/2023] [Accepted: 12/20/2023] [Indexed: 01/23/2024]
Abstract
Microcystin-LR (MC-LR) is a toxin produced by cyanobacteria, which is widely distributed in eutrophic water bodies and has multi-organ toxicity. Previous cytotoxicity studies have mostly elucidated the effects of MC-LR on intracellular-related factors, proteins, and DNA at the molecular level. However, there have been few studies on the adverse effects of MC-LR on cell ultrastructure and function. Therefore, research on the cytotoxicity of MC-LR in recent years was collected and summarized. It was found that MC-LR can induce a series of cytotoxic effects, including decreased cell viability, induced autophagy, apoptosis and necrosis, altered cell cycle, altered cell morphology, abnormal cell migration and invasion as well as leading to genetic damage. The above cytotoxic effects were related to the damage of various ultrastructure and functions such as cell membranes and mitochondria. Furthermore, MC-LR can disrupt cell ultrastructure and function by inducing oxidative stress and inhibiting protein phosphatase activity. In addition, the combined toxic effects of MC-LR and other environmental pollutants were investigated. This review explored the toxic targets of MC-LR at the subcellular level, which will provide new ideas for the prevention and treatment of multi-organ toxicity caused by MC-LR.
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Affiliation(s)
- Kangfeng Ge
- College of Public Health, Zhengzhou University, Zhengzhou, 450001, China
| | - Xingde Du
- College of Public Health, Zhengzhou University, Zhengzhou, 450001, China
| | - Haohao Liu
- Department of Public Health, First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450001, China
| | - Ruiyang Meng
- College of Public Health, Zhengzhou University, Zhengzhou, 450001, China
| | - Chunrui Wu
- College of Public Health, Zhengzhou University, Zhengzhou, 450001, China
| | - Zongxin Zhang
- College of Public Health, Zhengzhou University, Zhengzhou, 450001, China
| | - Xiao Liang
- College of Public Health, Zhengzhou University, Zhengzhou, 450001, China
| | - Jun Yang
- College of Public Health, Zhengzhou University, Zhengzhou, 450001, China
| | - Huizhen Zhang
- College of Public Health, Zhengzhou University, Zhengzhou, 450001, China.
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3
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Chowdhury RR, Rose S, Ezan F, Sovadinová I, Babica P, Langouët S. Hepatotoxicity of cyanotoxin microcystin-LR in human: Insights into mechanisms of action in the 3D culture model Hepoid-HepaRG. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2024; 342:123047. [PMID: 38036087 DOI: 10.1016/j.envpol.2023.123047] [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: 08/10/2023] [Revised: 11/03/2023] [Accepted: 11/23/2023] [Indexed: 12/02/2023]
Abstract
Microcystin-LR (MC-LR) is a potent hepatotoxin produced by harmful cyanobacterial blooms (CyanoHABs). MC-LR targets highly differentiated hepatocytes expressing organic anion transporting polypeptides OATP1B1 and OATP1B3 that are responsible for hepatocellular uptake of the toxin. The present study utilized an advanced 3D in vitro human liver model Hepoid-HepaRG based on the cultivation of collagen-matrix embedded multicellular spheroids composed of highly differentiated and polarized hepatocyte-like cells. 14-d-old Hepoid-HepaRG cultures showed increased expression of OATP1B1/1B3 and sensitivity to MC-LR cytotoxicity at concentrations >10 nM (48 h exposure, EC20 = 26 nM). MC-LR induced neither caspase 3/7 activity nor expression of the endoplasmic reticulum stress marker gene BiP/GRP78, but increased release of pro-inflammatory cytokine IL-8, indicating a necrotic type of cell death. Subcytotoxic (10 nM) and cytotoxic (≥100 nM) MC-LR concentrations disrupted hepatocyte functions, such as xenobiotic metabolism phase-I enzyme activities (cytochrome P450 1A/1B) and albumin secretion, along with reduced expression of CYP1A2 and ALB genes. MC-LR also decreased expression of HNF4A gene, a critical regulator of hepatocyte differentiation and function. Genes encoding hepatobiliary membrane transporters (OATP1B1, BSEP, NTCP), hepatocyte gap junctional gene connexin 32 and the epithelial cell marker E-cadherin were also downregulated. Simultaneous upregulation of connexin 43 gene, primarily expressed by liver progenitor and non-parenchymal cells, indicated a disruption of tissue homeostasis. This was associated with a shift in the expression ratio of E-cadherin to N-cadherin towards the mesenchymal cell marker, a process linked to epithelial-mesenchymal transition (EMT) and hepatocarcinogenesis. The effects observed in the human liver cell in vitro model revealed mechanisms that can potentially contribute to the MC-LR-induced promotion and progression of hepatocellular carcinoma (HCC). Hepoid-HepaRG cultures provide a robust, accessible and versatile in vitro model, capable of sensitively detecting hepatotoxic effects at toxicologically relevant concentrations, allowing for assessing hepatotoxicity mechanisms, human health hazards and impacts of environmental hepatotoxins, such as MC-LR.
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Affiliation(s)
- Riju R Chowdhury
- Masaryk University, Faculty of Science, RECETOX, Kotlářská 2, 61137, Brno, Czech Republic
| | - Sophie Rose
- University of Rennes, Inserm, EHESP, Irset (Institut de Recherche en santé, environnement et travail), UMR_S 1085, 35000, Rennes, France
| | - Frédéric Ezan
- University of Rennes, Inserm, EHESP, Irset (Institut de Recherche en santé, environnement et travail), UMR_S 1085, 35000, Rennes, France
| | - Iva Sovadinová
- Masaryk University, Faculty of Science, RECETOX, Kotlářská 2, 61137, Brno, Czech Republic
| | - Pavel Babica
- Masaryk University, Faculty of Science, RECETOX, Kotlářská 2, 61137, Brno, Czech Republic
| | - Sophie Langouët
- University of Rennes, Inserm, EHESP, Irset (Institut de Recherche en santé, environnement et travail), UMR_S 1085, 35000, Rennes, France.
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4
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Li B, Liu Y, Liu Y, Xie P. Excluding interference and detecting Microcystin-LR in the natural lakes and cells based a unique fluorescence method. WATER RESEARCH 2022; 221:118811. [PMID: 35810636 DOI: 10.1016/j.watres.2022.118811] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Revised: 06/27/2022] [Accepted: 07/01/2022] [Indexed: 06/15/2023]
Abstract
Cyanobacteria blooms that cause the death of aquatic and terrestrial organisms have attracted considerable attention since the 19th century. The most typical toxin in cyanobacteria blooms is cyanobacteria toxin, particularly microcystin-LR (MC-LR). Therefore, a simple and highly efficient method for detecting MC-LR plays a role in studying the ecological toxicology of MC-LR. However, as MC-LR itself is located in a complex environment, traditional techniques present complex and false-positive defects. To address the above issues, novel technologies should be explored and discovered. Herein, we describe the development of MC-BDKZ as the first paradigm of probes that can concurrently report MC-LR in natural lakes and cells. This novel material shows large Stokes Shift and possesses good photostability and high sensitivity. Considering the properties mentioned above, MC-BDKZ not only achieves the detection of MC-LR in the lake water samples, but also completes the imaging of exogenous MC-LR in cells. Moreover, the interference of many factors in the lake and cells is excluded completely in the process of MC-LR detection. We comprehensively analyzed the response principle and potential application of MC-BDKZ in the process of MC-LR detection. Compared with the conventional MC-LR detection technologies, fluorescence probe technology shows better convenience and greatly reduces distance from the practical application in vitro and in vivo. We envisioned that the development of this visual research tool could provide crucial clues for exploring the pathogenesis of MC-LR in body.
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Affiliation(s)
- Bingyan Li
- Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Sciences, Yunnan University, Kunming 650500, PR China
| | - Yipeng Liu
- Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Sciences, Yunnan University, Kunming 650500, PR China
| | - Yong Liu
- Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Sciences, Yunnan University, Kunming 650500, PR China.
| | - Ping Xie
- Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Sciences, Yunnan University, Kunming 650500, PR China; Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, PR China.
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5
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Hua S, Chen J, Wu L, Yu X, Ye J, Li Y, Zhu Y, Tian F. The monthly variation tendency of microcystin-LR levels in the Huangpu River (China) by applications of ELISA and HPLC. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:56876-56884. [PMID: 35347625 DOI: 10.1007/s11356-022-19791-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2021] [Accepted: 03/14/2022] [Indexed: 06/14/2023]
Abstract
In this study, the contents of microcystin-LR (MC-LR) of Microcystis aeruginosa cultures in the laboratory and natural water samples from the Huangpu River in different seasons were detected through enzyme-linked immunosorbent assay (ELISA) and high-performance liquid chromatography (HPLC), respectively. Excellent correlation between the two methods was obtained (R2 > 0.99). ELISA was a reliable and simple method with high reproducibility (coefficient of variation < 25%) and satisfactory recovery for the monitoring of low levels of MC-LR. MC-LR concentrations in Huangpu River varied with the seasonal variation, which peaked in August with the temperature over 30 °C and then gradually declined with the decreasing temperature after August. The highest MC-LR concentration in the Huangpu River was below the WHO drinking water quality standard (1 µg/L). These results indicated that warm temperature accelerated the MC-LR synthesis and release, and it is necessary to regularly monitor the MC-LR levels, especially during the high algae period in summer. ELISA can be applied to detect the low levels of MC-LR in the field without complex treatment, avoiding the samples from denaturation and degradation during the transportation. Hence, ELISA is a better alternative of HPLC when HPLC is unavailable, especially when rapid testing is required in routine MC-LR analysis.
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Affiliation(s)
- Sijia Hua
- School of Chemical and Environmental Engineering, Shanghai Institute of Technology, Shanghai, 201418, China
| | - Jiawen Chen
- School of Chemical and Environmental Engineering, Shanghai Institute of Technology, Shanghai, 201418, China
| | - Liang Wu
- Department of Chemical and Environmental Engineering, University of California, Riverside, CA, 92521, USA
- Program of Environmental Toxicology, University of California, Riverside, CA, 92521, USA
| | - Xinyue Yu
- School of Chemical and Environmental Engineering, Shanghai Institute of Technology, Shanghai, 201418, China
| | - Jing Ye
- School of Chemical and Environmental Engineering, Shanghai Institute of Technology, Shanghai, 201418, China.
| | - Yuanting Li
- School of Chemical and Environmental Engineering, Shanghai Institute of Technology, Shanghai, 201418, China
| | - Yongqiang Zhu
- School of Chemical and Environmental Engineering, Shanghai Institute of Technology, Shanghai, 201418, China
| | - Fuxiang Tian
- School of Chemical and Environmental Engineering, Shanghai Institute of Technology, Shanghai, 201418, China
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6
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Wang S, Ding P, Lu S, Wu P, Wei X, Huang R, Kai T. Cell density-dependent regulation of microcystin synthetase genes (mcy) expression and microcystin-LR production in Microcystis aeruginosa that mimics quorum sensing. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2021; 220:112330. [PMID: 34020285 DOI: 10.1016/j.ecoenv.2021.112330] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 05/07/2021] [Accepted: 05/08/2021] [Indexed: 06/12/2023]
Abstract
As the secondary metabolites of cyanobacterial harmful algal blooms (Cyano-HABs), microcystins (MCs) were generated under various environmental and cellular conditions. The understanding of the causes of MCs generation is of great interest in the field of water treatment and environmental science. In this work, we studied how Microcystis aeruginosa (FACHB-905) cell densities affect the MCs synthetase genes (mcy) expression, microcystin-LR (MC-LR) and quorum sensing molecules (Acyl-homoserine lactones (AHLs)) production. An electrochemical sensor was developed here for sensitive and quantitative detection of MC-LR that cultured at different cell densities. The results showed that mcy expression and MC-LR concentration started to increase when the cell density reached ca. 22 × 106 cells/mL, and was significantly increased with increasing cell densities. Moreover, the up-regulation of AHLs with increasing cell densities revealed that MC-LR is quorum sensing-mediated. Our results undoubtedly confirmed that MC-LR was produced in a cell density-dependent way that mimics quorum sensing, and the minimum cell density (ca. 22 × 106 cells/mL) that was required to produce MC-LR was provided and offered a reference standard for the prevention and control of MCs pollution in the actual water environment.
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Affiliation(s)
- Shanlin Wang
- Xiang Ya School of Public Health, Central South University, Changsha, Hunan 410078, China; Hunan Provincial Key Laboratory of Clinical Epidemiology, Changsha, Hunan 410078, China
| | - Ping Ding
- Xiang Ya School of Public Health, Central South University, Changsha, Hunan 410078, China; Hunan Provincial Key Laboratory of Clinical Epidemiology, Changsha, Hunan 410078, China
| | - Siyu Lu
- Xiang Ya School of Public Health, Central South University, Changsha, Hunan 410078, China; Hunan Provincial Key Laboratory of Clinical Epidemiology, Changsha, Hunan 410078, China
| | - Pian Wu
- Xiang Ya School of Public Health, Central South University, Changsha, Hunan 410078, China; Hunan Provincial Key Laboratory of Clinical Epidemiology, Changsha, Hunan 410078, China
| | - Xiaoqian Wei
- Xiang Ya School of Public Health, Central South University, Changsha, Hunan 410078, China; Hunan Provincial Key Laboratory of Clinical Epidemiology, Changsha, Hunan 410078, China
| | - Ruixue Huang
- Xiang Ya School of Public Health, Central South University, Changsha, Hunan 410078, China; Hunan Provincial Key Laboratory of Clinical Epidemiology, Changsha, Hunan 410078, China
| | - Tianhan Kai
- Xiang Ya School of Public Health, Central South University, Changsha, Hunan 410078, China; College of Chemistry and Chemical Engineering, Central South University, Changsha, Hunan 410083, China.
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7
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Wang Y, Xiao X, Wang F, Yang Z, Yue J, Shi J, Ke F, Xie Z, Fan Y. An identified PfHMGB1 promotes microcystin-LR-induced liver injury of yellow catfish (Pelteobagrus fulvidraco). ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2021; 207:111266. [PMID: 32919194 DOI: 10.1016/j.ecoenv.2020.111266] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 08/23/2020] [Accepted: 08/27/2020] [Indexed: 06/11/2023]
Abstract
Microcystin-LR (MC-LR) is a potent hepatotoxin that can cause liver inflammation and injury. However, the mode of action of related inflammatory factors is not fully understood. PfHMGB1 is an inflammatory factor induced at the mRNA level in the liver of juvenile yellow catfish (Pelteobagrus fulvidraco) that were intraperitoneally injected with 50 μg/kg MC-LR. The PfHMGB1 mRNA level was highest in the liver and muscle among 11 tissues examined. The full-length cDNA sequence of PfHMGB1 was cloned and overexpressed in E. coli, and the purified protein rPfHMGB1 demonstrated DNA binding affinity. Endotoxin-free rPfHMGB1 (6-150 μg/mL) also showed dose-dependent hepatotoxicity and induced inflammatory gene expression of primary hepatocytes. PfHMGB1 antibody (anti-PfHMGB1) in vitro reduced MC-LR (30 and 50 μmol/L)-induced hepatotoxicity, suggesting PfHMGB1 is important in the toxic effects of MC-LR. In vivo study showed that MC-LR upregulated PfHMGB1 protein in the liver. The anti-PfHMGB1 blocked its counterpart and reduced ALT/AST activities after MC-LR exposure. Anti-PfHMGB1 partly neutralized MC-LR-induced hepatocyte disorganization, nucleus shrinkage, mitochondria, and rough endoplasmic reticula destruction. These findings suggest that PfHMGB1 promotes MC-LR-induced liver damage in the yellow catfish. HMGB1 may help protect catfish against widespread microcystin pollution.
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Affiliation(s)
- Yun Wang
- Hubei Key Laboratory of Environmental and Health Effects of Persistent Toxic Substances, Institute of Environment and Health, Jianghan University, Hubei Province, Wuhan, 430056, China; Henan Province Key Laboratory of Water Pollution Control and Rehabilitation Technology, Henan University of Urban Construction, Pingdingshan, 467036, China.
| | - Xiaoxue Xiao
- Henan Province Key Laboratory of Water Pollution Control and Rehabilitation Technology, Henan University of Urban Construction, Pingdingshan, 467036, China
| | - Feijie Wang
- Henan Province Key Laboratory of Water Pollution Control and Rehabilitation Technology, Henan University of Urban Construction, Pingdingshan, 467036, China
| | - Zupeng Yang
- Henan Province Key Laboratory of Water Pollution Control and Rehabilitation Technology, Henan University of Urban Construction, Pingdingshan, 467036, China
| | - Jingkai Yue
- Henan Province Key Laboratory of Water Pollution Control and Rehabilitation Technology, Henan University of Urban Construction, Pingdingshan, 467036, China
| | - Jiale Shi
- Henan Province Key Laboratory of Water Pollution Control and Rehabilitation Technology, Henan University of Urban Construction, Pingdingshan, 467036, China
| | - Fei Ke
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Zhaohui Xie
- Henan Province Key Laboratory of Water Pollution Control and Rehabilitation Technology, Henan University of Urban Construction, Pingdingshan, 467036, China
| | - Yanru Fan
- Henan Province Key Laboratory of Water Pollution Control and Rehabilitation Technology, Henan University of Urban Construction, Pingdingshan, 467036, China
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8
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Xiao C, Mei F, Ren G, Long L, Chen M, Fang X, Li J, Li K, Tang Y, Huang T, Deng W. Synergistic Effect of MC-LR and C-Terminal Truncated HBx on HepG2 Cells and Their Effects on PP2A Mediated Downstream Target of MAPK Signaling Pathway. Front Genet 2020; 11:537785. [PMID: 33193609 PMCID: PMC7593820 DOI: 10.3389/fgene.2020.537785] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Accepted: 09/28/2020] [Indexed: 12/24/2022] Open
Abstract
C-terminally truncated hepatitis B virus (HBV) X (ctHBx) infection and exposure to microcystins-LR (MC-LR) can lead to human hepatitis and liver cancer, but the mechanism associated with their synergistically effects not been fully elucidated. The ctHBx (HBxΔ4 and HBxΔ32) lentivirus were constructed and transfected into the HepG2 cells. Then we investigated the function of MC-LR and ctHBx using the molecular biology approaches, including enzyme-linked immunosorbent assay, clone formation assay, scratch wound testing, transwell assays, carried out flow cytometry respectively to examine cell cycle and apoptosis in each group, and detected the related proteins of HBx, MEK/ERK/JNK/p38 in mitogen-activated protein kinase (MAPK) pathway and the downstream proteins such as cdc2, cdc25C, and p53 by western blotting. We found that the protein phosphorylase 2A (PP2A) enzyme activity in MC-LR and HBxΔ32/HBxΔ4 groups decreased more than in MC-LR and HBx group at the same time point and MC-LR concentration (P < 0.05). Meanwhile the proliferation, migration, invasion and colony formation capability of HepG2 cells were significantly enhanced in MC-LR and ctHBx groups (P < 0.05). In addition the proportion of S stage cells in the MC-LR-treated HBxΔ32/HBxΔ4 groups was significantly greater than that in the untreated groups (P < 0.05). Furthermore, the protein expression of MAPK signaling pathway including phospho-MEK1/2, ERKl/2, p38, and JNK were up-regulated by MC-LR and HBxΔ32, and the expression of cyclin-related proteins, including p53, cdc25C, and cdc2 were also activated (P < 0.05). Taken together, our findings revealed the essential significance of the MC-LR and ctHBx on the PP2A/MAPK/p53, cdc25C and cdc2 axis in the formation and development of HCC and identified MC-LR and ctHBx as potential causal cofactors of hepatocarcinogenesis.
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Affiliation(s)
- Chanchan Xiao
- Guangxi Medical University Cancer Hospital, Nanning, China
| | - Fanbiao Mei
- Guangxi Medical University Cancer Hospital, Nanning, China
| | - Guanhua Ren
- Guangxi Medical University Cancer Hospital, Nanning, China
| | - Long Long
- Guangxi Medical University Cancer Hospital, Nanning, China
| | - Maojian Chen
- Guangxi Medical University Cancer Hospital, Nanning, China
| | - Xiang Fang
- Guangxi Medical University Cancer Hospital, Nanning, China
| | - Jilin Li
- Guangxi Medical University Cancer Hospital, Nanning, China
| | - Kezhi Li
- Guangxi Medical University Cancer Hospital, Nanning, China
| | - Yanping Tang
- Guangxi Medical University Cancer Hospital, Nanning, China
| | - Tianren Huang
- Guangxi Medical University Cancer Hospital, Nanning, China
| | - Wei Deng
- Guangxi Medical University Cancer Hospital, Nanning, China
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9
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Zhang Y, Zhang J, Wang E, Qian W, Fan Y, Feng Y, Yin H, Li Y, Wang Y, Yuan T. Microcystin-Leucine-Arginine Induces Tau Pathology Through Bα Degradation via Protein Phosphatase 2A Demethylation and Associated Glycogen Synthase Kinase-3β Phosphorylation. Toxicol Sci 2019; 162:475-487. [PMID: 29228318 DOI: 10.1093/toxsci/kfx271] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Microcystin-leucine-arginine (MC-LR) has been implicated as a potential environmental factor in Alzheimer's disease because of its potent inhibition of protein phosphatase 2A (PP2A) activity, but experimental evidence to support its detailed neurotoxic effects and their underlying mechanisms has been lacking. The present study investigated the role of PP2A catalytic subunit (PP2Ac) demethylation and its link with glycogen synthase kinase-3β (GSK)-3β in tau hyperphosphorylation induced by MC-LR. The results showed that MC-LR treatment significantly increased demethylation of PP2Ac, with a concomitant increase in GSK-3β phosphorylation at Ser9 resulting in elevated tau hyperphosphorylation at PP2A-favorable sites in SH-SY5Y cells and rat hippocampus. Coimmunoprecipitation experiments showed that MC-LR treatment dissociated PP2Ac from Bα, making it incompetent in binding tau, thus causing tau hyperphosphorylation. Moreover, we found that inhibition of PP2A resulted in an increase in phosphorylation of GSK-3β at Ser9 and a decrease in GSK-3β activity, which further promoted demethylation of PP2Ac induced by MC-LR. These findings suggest a scenario in which MC-LR-mediated demethylation of PP2Ac is associated with GSK-3β phosphorylation at Ser9 and contributes to dissociation of Bα from PP2Ac, which would result in Bα degradation and disruption of PP2A/Bα-tau interactions, thus promoting tau hyperphosphorylation and paired helical filaments-tau accumulation and, consequently, axonal degeneration and cell death.
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Affiliation(s)
- Yali Zhang
- Department of Biochemistry and Molecular Biology, School of Medicine
| | - Jiahui Zhang
- Department of Biochemistry and Molecular Biology, School of Medicine
| | - Enhao Wang
- Department of Biochemistry and Molecular Biology, School of Medicine
| | - Wei Qian
- Department of Biochemistry and Molecular Biology, School of Medicine.,Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education and Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jangsu 226001, China
| | - Yan Fan
- Department of Biochemistry and Molecular Biology, School of Medicine
| | - Ying Feng
- Department of Biochemistry and Molecular Biology, School of Medicine
| | - Haimeng Yin
- Department of Biochemistry and Molecular Biology, School of Medicine
| | - Yang Li
- Department of Biochemistry and Molecular Biology, School of Medicine
| | - Yuning Wang
- Department of Biochemistry and Molecular Biology, School of Medicine
| | - Tianli Yuan
- Department of Biochemistry and Molecular Biology, School of Medicine
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10
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Adegoke EO, Adeniran SO, Zeng Y, Wang X, Wang H, Wang C, Zhang H, Zheng P, Zhang G. Pharmacological inhibition of TLR4/NF-κB with TLR4-IN-C34 attenuated microcystin-leucine arginine toxicity in bovine Sertoli cells. J Appl Toxicol 2019; 39:832-843. [PMID: 30671980 DOI: 10.1002/jat.3771] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Revised: 12/08/2018] [Accepted: 12/11/2018] [Indexed: 01/17/2023]
Abstract
This study investigated the pharmacological inhibition of the toll-like receptor 4 (TLR4) genes as a measure to attenuate microcystin-LR (MC-LR) reproductive toxicity. Bovine Sertoli cells were pretreated with TLR4-IN-C34 (C34) for 1 hour. Thereafter the pretreated and non-pretreated Sertoli cells were cultured in medium containing 10% heat-activated fetal bovine serum + 80 μg/L MC-LR for 24 hours to assess the ability of TLR4-IN-C34 to attenuate the toxic effects of MC-LR. The results showed that TLR4-IN-C34 inhibited MC-LR-induced mitochondria membrane damage, mitophagy and downregulation of blood-testis barrier constituent proteins via TLR4/nuclear factor-kappaB and mitochondria-mediated apoptosis signaling pathway blockage. The downregulation of the mitochondria electron transport chain, energy production and DNA replication related genes (mt-ND2, COX-1, COX-2, ACAT, mtTFA) and upregulation of inflammatory cytokines (interleukin [IL]-6, tumor necrosis factor-α, IL-1β, interferon-γ, IL-4, IL-10, IL-13 and transforming growth factor β1) were modulated by TLR4-IN-C34. Taken together, we conclude that TLR4-IN-C34 inhibits MC-LR-related disruption of mitochondria membrane, mitophagy and downregulation of blood-testis barrier proteins of the bovine Sertoli cell via cytochrome c release and TLR4 signaling blockage.
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Affiliation(s)
- Elikanah Olusayo Adegoke
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science and Technology, Northeast Agricultural University Harbin, People's Republic of China
| | - Samson Olugbenga Adeniran
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science and Technology, Northeast Agricultural University Harbin, People's Republic of China
| | - Yue Zeng
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science and Technology, Northeast Agricultural University Harbin, People's Republic of China
| | - Xue Wang
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science and Technology, Northeast Agricultural University Harbin, People's Republic of China
| | - Hao Wang
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science and Technology, Northeast Agricultural University Harbin, People's Republic of China
| | - Chen Wang
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science and Technology, Northeast Agricultural University Harbin, People's Republic of China
| | - Han Zhang
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science and Technology, Northeast Agricultural University Harbin, People's Republic of China
| | - Peng Zheng
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science and Technology, Northeast Agricultural University Harbin, People's Republic of China
| | - Guixue Zhang
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science and Technology, Northeast Agricultural University Harbin, People's Republic of China
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Adegoke EO, Xue W, Machebe NS, Adeniran SO, Hao W, Chen W, Han Z, Guixue Z, Peng Z. Sodium Selenite inhibits mitophagy, downregulation and mislocalization of blood-testis barrier proteins of bovine Sertoli cell exposed to microcystin-leucine arginine (MC-LR) via TLR4/NF-kB and mitochondrial signaling pathways blockage. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2018; 166:165-175. [PMID: 30267989 DOI: 10.1016/j.ecoenv.2018.09.073] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Revised: 09/11/2018] [Accepted: 09/15/2018] [Indexed: 06/08/2023]
Abstract
This study was conducted to investigate the ameliorative effect of selenium on microcystin-LR induced toxicity in bovine Sertoli cells. Bovine Sertoli cells were pretreated with selenium (Na2SeO3) for 24 h after which selenium pretreated and non-pretreated Sertoli cells were cultured in medium containing 10% heat activated fetal bovine serum FBS+ 80 µg/L MC-LR to assess its ameliorative effect on MC-LR toxicity. The results show that selenium pretreatment inhibited the MC-LR induced mitophagy, downregulation and mislocalization of blood-testis barrier constituent proteins in bovine Sertoli cells via NF-kB and cytochrome c release blockage. The observed downregulation of electron transport chain (ETC) related genes (mt-ND2, COX-1, COX-2) and upregulation of inflammatory cytokines (IL-6, TNF-α, IL-1β, IFN-γ, IL-4, IL-10, 1 L-13, TGFβ1) in non-pretreated cells exposed to MC-LR were ameliorated in selenium pretreated cells. There was no significant difference (P > 0.05) in the protein levels of blood-testis barrier constituent proteins (ZO-1, occludin, connexin-43, CTNNB1, N-cadherin) and mitochondria related genes (mt-ND2, COX-1, COX-2, ACAT1, mtTFA) of selenium pretreated Sertoli cell compared to the control. Taken together, we conclude that selenium inhibits MC-LR caused Mitophagy, downregulation and mislocalization of blood-testis barrier proteins of bovine Sertoli cell via mitochondrial and TLR4/NF-kB signaling pathways blockage.
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Affiliation(s)
- E O Adegoke
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science and Technology, Northeast Agricultural University Harbin, PR China
| | - Wang Xue
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science and Technology, Northeast Agricultural University Harbin, PR China
| | - N S Machebe
- Department of Animal Science, University of Nigeria, Nsukka, Nigeria
| | - S O Adeniran
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science and Technology, Northeast Agricultural University Harbin, PR China
| | - Wang Hao
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science and Technology, Northeast Agricultural University Harbin, PR China
| | - Wang Chen
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science and Technology, Northeast Agricultural University Harbin, PR China
| | - Zhang Han
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science and Technology, Northeast Agricultural University Harbin, PR China
| | - Zhang Guixue
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science and Technology, Northeast Agricultural University Harbin, PR China.
| | - Zheng Peng
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science and Technology, Northeast Agricultural University Harbin, PR China.
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Basu A, Dydowiczová A, Čtveráčková L, Jaša L, Trosko JE, Bláha L, Babica P. Assessment of Hepatotoxic Potential of Cyanobacterial Toxins Using 3D In Vitro Model of Adult Human Liver Stem Cells. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:10078-10088. [PMID: 30059226 DOI: 10.1021/acs.est.8b02291] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Cyanotoxins microcystin-LR (MC-LR) and cylindrospermopsin (CYN) represent hazardous waterborne contaminants and potent human hepatotoxins. However, in vitro monolayer cultures of hepatic cell lines were found to recapitulate, poorly, major hepatocyte-specific functions and inadequately predict hepatotoxic effects of MC-LR and CYN. We utilized 3-dimensional (3D), scaffold-free spheroid cultures of human telomerase-immortalized adult liver stem cells HL1-hT1 to evaluate hepatotoxic potential of MC-LR and CYN. In monolayer cultures of HL1-hT1 cells, MC-LR did not induce cytotoxic effects (EC50 > 10 micromol/L), while CYN inhibited cell growth and viability (48h-96h EC50 ≈ 5.5-0.6 micromol/L). Growth and viability of small growing spheroids were inhibited by both cyanotoxins (≥0.1 micromol/L) and were associated with blebbing and disintegration at the spheroid surface. Hepatospheroid damage and viability reduction were observed also in large mature spheroids, with viability 96h-EC50 values being 0.04 micromol/L for MC-LR and 0.1 micromol/L for CYN, and No Observed Effect Concentrations <0.01 micromol/L. Spheroid cultures of adult human liver stem cells HL1-hT1 exhibit sensitivity comparable to cultures of primary hepatocytes and provide a simple, practical, and cost-effective tool, which can be effectively used in environmental and toxicological research, including assessment of hepatotoxic potential and effect-based monitoring of various samples contaminated with toxic cyanobacteria.
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Affiliation(s)
- Amrita Basu
- RECETOX, Faculty of Science , Masaryk University , Kamenice 753/5 , Brno 625 00 , Czech Republic
| | - Aneta Dydowiczová
- RECETOX, Faculty of Science , Masaryk University , Kamenice 753/5 , Brno 625 00 , Czech Republic
| | - Lucie Čtveráčková
- RECETOX, Faculty of Science , Masaryk University , Kamenice 753/5 , Brno 625 00 , Czech Republic
| | - Libor Jaša
- RECETOX, Faculty of Science , Masaryk University , Kamenice 753/5 , Brno 625 00 , Czech Republic
| | - James E Trosko
- Department of Pediatrics and Human Development & Institute for Integrative Toxicology , Michigan State University , 1129 Farm Lane , East Lansing , 48824 Michigan , United States
| | - Luděk Bláha
- RECETOX, Faculty of Science , Masaryk University , Kamenice 753/5 , Brno 625 00 , Czech Republic
| | - Pavel Babica
- RECETOX, Faculty of Science , Masaryk University , Kamenice 753/5 , Brno 625 00 , Czech Republic
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Papkovsky DB, Zhdanov AV. Phosphorescence based O 2 sensors - Essential tools for monitoring cell and tissue oxygenation and its impact on metabolism. Free Radic Biol Med 2016; 101:202-210. [PMID: 27789291 DOI: 10.1016/j.freeradbiomed.2016.09.018] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Revised: 09/13/2016] [Accepted: 09/22/2016] [Indexed: 12/27/2022]
Abstract
Oxygenation condition at the cellular level is a critical factor in tissue physiology and common pathophysiological states including cancer, metabolic disorders, ischemia-reperfusion injury and inflammation. O2 and ROS signalling and hypoxia research are rapidly growing areas spanning life and biomedical sciences, but still many current cell and tissue models and experimental set ups lack physiological relevance, particularly precise control of cellular O2. Quenched-phosphorescence O2 sensing enables implementation of such in situ control of cellular O2 and the creation of physiological conditions in respiring samples analysed in vitro. The advantages of optical O2 sensing are the non-invasive, contactless, real-time, quantitative monitoring of O2 concentration, which can be performed in the gas or liquid phase, macroscopically or microscopically, by point measurement or in imaging mode, with sub-cellular spatial resolution, in a flexible manner and with various cell and tissue models. Significantly, this same technology can also be used to probe the metabolism of cells and tissue under specific oxygenation conditions and their responses to changing conditions. Here we describe the range of available O2 sensing systems and tools, their analytical capabilities, uses in cell/tissue physiology and hypoxia research, and strategies for integration in routine experimental procedures.
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Affiliation(s)
- Dmitri B Papkovsky
- School of Biochemistry and Cell Biology, University College Cork, Cavanagh Pharmacy Building, College Road, Cork, Ireland.
| | - Alexander V Zhdanov
- School of Biochemistry and Cell Biology, University College Cork, Cavanagh Pharmacy Building, College Road, Cork, Ireland
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14
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Zhang X, Li J, Yang JY, Wood KV, Rothwell AP, Li W, Blatchley Iii ER. Chlorine/UV Process for Decomposition and Detoxification of Microcystin-LR. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2016; 50:7671-7678. [PMID: 27338715 DOI: 10.1021/acs.est.6b02009] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Microcystin-LR (MC-LR) is a potent hepatotoxin that is often associated with blooms of cyanobacteria. Experiments were conducted to evaluate the efficiency of the chlorine/UV process for MC-LR decomposition and detoxification. Chlorinated MC-LR was observed to be more photoactive than MC-LR. LC/MS analyses confirmed that the arginine moiety represented an important reaction site within the MC-LR molecule for conditions of chlorination below the chlorine demand of the molecule. Prechlorination activated MC-LR toward UV254 exposure by increasing the product of the molar absorption coefficient and the quantum yield of chloro-MC-LR, relative to the unchlorinated molecule. This mechanism of decay is fundamentally different than the conventional view of chlorine/UV as an advanced oxidation process. A toxicity assay based on human liver cells indicated MC-LR degradation byproducts in the chlorine/UV process possessed less cytotoxicity than those that resulted from chlorination or UV254 irradiation applied separately. MC-LR decomposition and detoxification in this combined process were more effective at pH 8.5 than at pH 7.5 or 6.5. These results suggest that the chlorine/UV process could represent an effective strategy for control of microcystins and their associated toxicity in drinking water supplies.
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Affiliation(s)
- Xinran Zhang
- School of Municipal and Environmental Engineering, Harbin Institute of Technology , Harbin, China
| | - Jing Li
- Department of Applied Chemistry, China Agricultural University , Beijing, China
| | - Jer-Yen Yang
- Department of Basic Medical Sciences & Center for Cancer Research, Purdue University , West Lafayette, Indiana 47907, United States
| | - Karl V Wood
- Campus-Wide Mass Spectrometry Center, Purdue University , West Lafayette, Indiana 47907, United States
| | - Arlene P Rothwell
- Campus-Wide Mass Spectrometry Center, Purdue University , West Lafayette, Indiana 47907, United States
| | - Weiguang Li
- School of Municipal and Environmental Engineering, Harbin Institute of Technology , Harbin, China
| | - Ernest R Blatchley Iii
- Lyles School of Civil Engineering, Purdue University , West Lafayette, Indiana 47907, United States
- Division of Environmental & Ecological Engineering, Purdue University , West Lafayette, Indiana 47907, United States
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15
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Sinha A, Jana NR. Separation of Microcystin-LR by Cyclodextrin-Functionalized Magnetic Composite of Colloidal Graphene and Porous Silica. ACS APPLIED MATERIALS & INTERFACES 2015; 7:9911-9919. [PMID: 25906257 DOI: 10.1021/acsami.5b02038] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Microcystin-LR belongs to the family of microcystins produced by cyanobacteria and known to be the most toxic of this family. Existence of cyanobacteria in water bodies leads to the contamination of drinking water with microcystin-LR and thus their separation is essential for an advanced water purification system. Here we report functional nanocomposite-based selective separation of microcystin-LR from contaminated water. We have synthesized cyclodextrin-functionalized magnetic composite of colloidal graphene and porous silica where the cyclodextrin component offers host-guest interaction with microcystin-LR and the magnetic component offers easier separation of microcystin-LR from water. High surface area and large extent of chemical functional groups offer high loading (up to 18 wt %) of cyclodextrin with these nanocomposites, and the dispersible form of the nanocomposite offers easier accessibility of cyclodextrin to microcystin-LR. We have shown that microcystin-LR separation efficiency is significantly enhanced after functionalization with cyclodextrin, and among all the tested cyclodextrins, γ-cyclodextrin offers the best performance. We have also found that graphene-based nanocomposite offers better performance over porous silica-based nanocomposite due to better accessibility of cyclodextrins for interaction with microcystin-LR. The proposed graphene-based functional nanocomposite is environment friendly, reusable, and applicable for advanced water purification.
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Affiliation(s)
- Arjyabaran Sinha
- Centre for Advanced Materials, Indian Association for the Cultivation of Science, Kolkata-700032, India
| | - Nikhil R Jana
- Centre for Advanced Materials, Indian Association for the Cultivation of Science, Kolkata-700032, India
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16
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Roegner AF, Puschner B. Aggregate culture: A more accurate predictor of microcystin toxicity for risk assessment. Toxicon 2014; 83:1-14. [PMID: 24593965 DOI: 10.1016/j.toxicon.2014.02.017] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2014] [Revised: 02/15/2014] [Accepted: 02/20/2014] [Indexed: 10/25/2022]
Abstract
Aggregate or spheroid culture has emerged as a more biologically relevant method for screening pharmaceutical compounds and understanding exact mechanism of action. Here in, the aggregate approach applied to the freshwater toxins, microcystins, further unearths exact mechanism(s) of toxicity and provides a markedly improved in vitro predictor of toxicity. Microcystins result in acute intoxication by binding covalently to protein phosphatase 1/2A, resulting in hepatocellular necrosis, hemorrhaging and death. Hepatocellular uptake by organic anion transporting polypeptides (OATPs), in addition to other intracellular sequelae, is considered essential for toxicity. In aggregate HepG2, expression of OAT1B1 and OATP1B3 significantly increased relative to monolayer culture. Uptake of two fluorescently labeled substrates significantly increased in aggregates compared with monolayer, confirmed by inhibition of uptake with known competitive substrates. Increased reaction oxygen species (ROS) production occurred following a three-hour exposure of microcystin LR at concentrations from 100 nM to 100 μM, with reversal by ROS scavengers, in contrast with no response in monolayers. These results suggest monolayer culture inadequately predict intracellular effects of microcystins and support evidence that aggregate culture more closely approximates in vivo form and function. The approach results in more reliable prediction of microcystin toxicity in vitro.
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Affiliation(s)
- Amber F Roegner
- Department of Molecular Biosciences, School of Veterinary Medicine, 1089 Veterinary Medicine Drive, University of California, Davis, CA 95616, USA
| | - Birgit Puschner
- Department of Molecular Biosciences, School of Veterinary Medicine, 1089 Veterinary Medicine Drive, University of California, Davis, CA 95616, USA.
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17
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Zhdanov AV, Waters AHC, Golubeva AV, Dmitriev RI, Papkovsky DB. Availability of the key metabolic substrates dictates the respiratory response of cancer cells to the mitochondrial uncoupling. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2013; 1837:51-62. [PMID: 23891695 DOI: 10.1016/j.bbabio.2013.07.008] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2013] [Revised: 07/16/2013] [Accepted: 07/17/2013] [Indexed: 12/12/2022]
Abstract
Active glycolysis and glutaminolysis provide bioenergetic stability of cancer cells in physiological conditions. Under hypoxia, metabolic and mitochondrial disorders, or pharmacological treatment, a deficit of key metabolic substrates may become life-threatening to cancer cells. We analysed the effects of mitochondrial uncoupling by FCCP on the respiration of cells fed by different combinations of Glc, Gal, Gln and Pyr. In cancer PC12 and HCT116 cells, a large increase in O2 consumption rate (OCR) upon uncoupling was only seen when Gln was combined with either Glc or Pyr. Inhibition of glutaminolysis with BPTES abolished this effect. Despite the key role of Gln, addition of FCCP inhibited respiration and induced apoptosis in cells supplied with Gln alone or Gal/Gln. For all substrate combinations, amplitude of respiratory responses to FCCP did not correlate with Akt, Erk and AMPK phosphorylation, cellular ATP, and resting OCR, mitochondrial Ca(2+) or membrane potential. However, we propose that proton motive force could modulate respiratory response to FCCP by regulating mitochondrial transport of Gln and Pyr, which decreases upon mitochondrial depolarisation. As a result, an increase in respiration upon uncoupling is abolished in cells, deprived of Gln or Pyr (Glc). Unlike PC12 or HCT116 cells, mouse embryonic fibroblasts were capable of generating pronounced response to FCCP when deprived of Gln, thus exhibiting lower dependence on glutaminolysis. Overall, the differential regulation of the respiratory response to FCCP by metabolic environment suggests that mitochondrial uncoupling has a potential for substrate-specific inhibition of cell function, and can be explored for selective cancer treatment.
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Affiliation(s)
- Alexander V Zhdanov
- Biochemistry Department, University College Cork, Cavanagh Pharmacy Building, College Road, Cork, Ireland.
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Ju J, Ruan Q, Li X, Liu R, Li Y, Pu Y, Yin L, Wang D. Neurotoxicological evaluation of microcystin-LR exposure at environmental relevant concentrations on nematode Caenorhabditis elegans. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2013; 20:1823-1830. [PMID: 22956115 DOI: 10.1007/s11356-012-1151-2] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2012] [Accepted: 08/27/2012] [Indexed: 06/01/2023]
Abstract
Previous studies have not examined the adverse effects of microcystin-LR (MC-LR) at environmental relevant concentrations on the development and functions of nervous system. The neurotoxic effects of MC-LR exposure on neurotransmitter systems were investigated in Caenorhabditis elegans. After exposing L1 larvae to 0.1, 1, 10, and 100 μg l(-1) of MC-LR for 8 and 24 h, the adverse effects on GABAergic, cholinergic, serotonergic, dopaminergic, and glutamatergic neurons were examined. The expression levels of genes required for development and functions of GABAergic neurons were further investigated. Body bend frequency and head thrash frequency decreased significantly after MC-LR exposure for 8 h at concentrations more than 1 μg l(-1) and after MC-LR exposure for 24 h at concentrations more than 0.1 μg l(-1). Loss of GABAergic neurons increased significantly in a dose-dependent manner after MC-LR exposure at concentrations more than 0.1 μg l(-1). In contrast, no obvious neuronal losses or morphologic changes were observed in cholinergic, serotonergic, dopaminergic, and glutamatergic neurons in MC-LR-exposed nematodes. Quantitative real-time PCR assay further showed that expression levels of unc-30, unc-46, unc-47, and exp-1 genes required for development and function of GABAergic neurons decreased significantly in nematodes exposed to MC-LR at concentrations more than 0.1 or 1 μg l(-1). MC-LR at environmental relevant concentrations caused neurobehavioral defects, which may be largely due to the neuronal loss and the alterations of expression level of genes required for GABAergic neurotransmitter system in C. elegans.
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Affiliation(s)
- Jingjuan Ju
- Key Laboratory of Environmental Medicine Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing, 210009, China
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Zhang XX, Fu Z, Zhang Z, Miao C, Xu P, Wang T, Yang L, Cheng S. Microcystin-LR promotes melanoma cell invasion and enhances matrix metalloproteinase-2/-9 expression mediated by NF-κB activation. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2012; 46:11319-11326. [PMID: 22992115 DOI: 10.1021/es3024989] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
This study aimed to explore the molecular mechanisms behind the stimulation effects of microcystin-LR (a well-known cyanobacterial toxin produced in eutrophic lakes or reservoirs) on cancer cell invasion and matrix metalloproteinases (MMPs) expression. Boyden chamber assay showed that microcystin-LR exposure (>12.5 nM) evidently enhanced the invasion ability of the melanoma cells (MDA-MB-435). Tumor Metastasis PCR Array demonstrated that 24 h microcystin-LR treatment (25 nM) caused overexpression of eight genes involved in tumor metastasis, including MMP-2, MMP-9, and MMP-13. Quantitative real-time PCR, Western blotting and gelatin zymography consistently demonstrated that mRNA and protein levels of MMP-2/-9 were increased in the cells after microcystin-LR exposure (P < 0.05 each). Immunofluorescence assay and electrophoretic mobility shift assay revealed that microcystin-LR could activate nuclear factor kappaB (NF-κB) by accelerating NF-κB translocation into the nucleus and enhancing NF-κB binding ability. Furthermore, addition of NF-κB inhibitor in culture medium could suppress the invasiveness enhancement and MMP-2/-9 overexpression. This study indicates that microcystin-LR can act as a NF-κB activator to promote MMP-2/-9 expression and melanoma cell invasion, which deserves more environmental health concerns.
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Affiliation(s)
- Xu-Xiang Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210046, China
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Zhang Z, Zhang XX, Qin W, Xu L, Wang T, Cheng S, Yang L. Effects of microcystin-LR exposure on matrix metalloproteinase-2/-9 expression and cancer cell migration. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2012; 77:88-93. [PMID: 22088328 DOI: 10.1016/j.ecoenv.2011.10.022] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2011] [Revised: 10/21/2011] [Accepted: 10/25/2011] [Indexed: 05/31/2023]
Abstract
This study assessed the effects of microcystin-LR (MC-LR) exposure on matrix metalloproteinases (MMPs) expression and cancer cell migration. After male mice were orally administered with different concentrations of MC-LR for 270 d, histopathologic observation revealed an obvious hepatic lymphocyte infiltration or fatty degeneration. Immunohistochemical staining and enzyme-linked immunosorbent assay demonstrated that MC-LR treatment (even at 1 nM) caused up-regulated expressions of hepatic MMP-2/-9. Quantitative reverse-transcriptase PCR showed that the exposure to 80 nM MC-LR induced an increase of MMP-2/-9 mRNA levels by 1.0 and 1.9 fold. Breast cancer cells (MDA-MB-435s) were also cultured with MC-LR solutions and a wound healing assay demonstrated that MC-LR posed a time/dose-dependent stimulation effect on migration of the cancer cells. Gelatin electrophoresis and quantitative PCR showed significant increases in cellular MMP-2/-9 expressions after MC-LR exposure. This study indicated that chronic exposure to MC-LR could alter MMP-2/-9 expressions and stimulate cancer cell migration.
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Affiliation(s)
- Zongyao Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210046, China
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Sassolas A, Catanante G, Fournier D, Marty JL. Development of a colorimetric inhibition assay for microcystin-LR detection: comparison of the sensitivity of different protein phosphatases. Talanta 2011; 85:2498-503. [PMID: 21962674 DOI: 10.1016/j.talanta.2011.07.101] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2011] [Revised: 07/28/2011] [Accepted: 07/29/2011] [Indexed: 10/17/2022]
Abstract
A colorimetric protein phosphatase (PP) inhibition test for the detection of microcystin-LR (MC-LR) has been developed. Three PP2As, one recombinant and two natural versions, as well as one PP1 produced by molecular engineering, were tested. First, assays were performed using the enzymes in solution to compare their sensitivity to MC-LR. The PP2A purchased from ZEU Immunotec and PP1 appeared more sensitive to the toxin than the other enzymes. With PP2A from ZEU Immunotec, the colorimetric test showed a detection limit of 0.0039 μg L(-1) and an IC(50) value of 0.21 μg L(-1). With PP1, the assay gave a detection limit of 0.05 μg L(-1) and an IC(50) value of 0.56 μg L(-1). Therefore, this assay allowed the detection of lower microcystin-LR (MC-LR) concentrations than the maximum level (1 μg L(-1)) recommended by the World Health Organisation (WHO). The main drawback of this PP-based approach in solution is poor enzyme stabilisation. To overcome this problem, enzymes were entrapped within either a photopolymer or an agarose gel. PP2A from ZEU Immunotec and PP1 were immobilised at the bottom of microwells. The agarose-based tests performed better than the photopolymer-based assay for all of the enzymes. Therefore, the agarose gel is a good candidate to replace the photopolymer, which is generally used in PP-immobilising membranes. The assays based on enzyme-entrapping agarose gels showed detection limits equal to 0.17 μg L(-1) and 0.29 μg L(-1) with immobilised PP2A from ZEU and PP1, respectively. In view of these performances, these tests can potentially be used for monitoring water quality.
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Affiliation(s)
- Audrey Sassolas
- Laboratoire IMAGES, bâtiment S, 52 avenue Paul Alduy, 66860 Perpignan cedex, France.
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Queirós RB, Silva SO, Noronha JP, Frazão O, Jorge P, Aguilar G, Marques PVS, Sales MGF. Microcystin-LR detection in water by the Fabry-Pérot interferometer using an optical fibre coated with a sol-gel imprinted sensing membrane. Biosens Bioelectron 2011; 26:3932-7. [PMID: 21489775 DOI: 10.1016/j.bios.2011.03.015] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2010] [Revised: 03/01/2011] [Accepted: 03/17/2011] [Indexed: 10/18/2022]
Abstract
Cyanobacteria deteriorate the water quality and are responsible for emerging outbreaks and epidemics causing harmful diseases in Humans and animals because of their toxins. Microcystin-LR (MCT) is one of the most relevant cyanotoxin, being the most widely studied hepatotoxin. For safety purposes, the World Health Organization recommends a maximum value of 1 μg L(-1) of MCT in drinking water. Therefore, there is a great demand for remote and real-time sensing techniques to detect and quantify MCT. In this work a Fabry-Pérot sensing probe based on an optical fibre tip coated with a MCT selective thin film is presented. The membranes were developed by imprinting MCT in a sol-gel matrix that was applied over the tip of the fibre by dip coating. The imprinting effect was obtained by curing the sol-gel membrane, prepared with (3-aminopropyl) trimethoxysilane (APTMS), diphenyl-dimethoxysilane (DPDMS), tetraethoxysilane (TEOS), in the presence of MCT. The imprinting effect was tested by preparing a similar membrane without template. In general, the fibre Fabry-Pérot with a Molecular Imprinted Polymer (MIP) sensor showed low thermal effect, thus avoiding the need of temperature control in field applications. It presented a linear response to MCT concentration within 0.3-1.4 μg L(-1) with a sensitivity of -12.4±0.7 nm L μg(-1). The corresponding Non-Imprinted Polymer (NIP) displayed linear behaviour for the same MCT concentration range, but with much less sensitivity, of -5.9±0.2 nm L μg(-1). The method shows excellent selectivity for MCT against other species co-existing with the analyte in environmental waters. It was successfully applied to the determination of MCT in contaminated samples. The main advantages of the proposed optical sensor include high sensitivity and specificity, low-cost, robustness, easy preparation and preservation.
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Affiliation(s)
- Raquel B Queirós
- INESC-Porto, UOSE, Rua do Campo Alegre, Portugal; Departamento de Física, Faculdade de Ciências, Universidade do Porto, Portugal; BIOMARK/ISEP, Instituto Superior de Engenharia do Porto, Porto, Portugal
| | - S O Silva
- INESC-Porto, UOSE, Rua do Campo Alegre, Portugal; Departamento de Física, Faculdade de Ciências, Universidade do Porto, Portugal
| | - J P Noronha
- REQUIMTE/FCT-UNL, Faculdade de Ciência e Tecnologia, Universidade Nova de Lisboa, Portugal
| | - O Frazão
- INESC-Porto, UOSE, Rua do Campo Alegre, Portugal
| | - P Jorge
- INESC-Porto, UOSE, Rua do Campo Alegre, Portugal
| | - G Aguilar
- INESC-Porto, UOSE, Rua do Campo Alegre, Portugal
| | - P V S Marques
- INESC-Porto, UOSE, Rua do Campo Alegre, Portugal; Departamento de Física, Faculdade de Ciências, Universidade do Porto, Portugal
| | - M G F Sales
- BIOMARK/ISEP, Instituto Superior de Engenharia do Porto, Porto, Portugal
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