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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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He J, Chen Y, Dai S, Chen F, Wang Y, Shi T, Chen L, Liu Y, Chen J, Xie P. First insights into region-specific lipidome alterations of prefrontal cortex and hippocampus of mice exposed chronically to microcystins. ENVIRONMENT INTERNATIONAL 2023; 177:108018. [PMID: 37329758 DOI: 10.1016/j.envint.2023.108018] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2023] [Revised: 05/31/2023] [Accepted: 06/01/2023] [Indexed: 06/19/2023]
Abstract
Microcystins (MCs), a group of most widespread freshwater cyanotoxins that possess strong neurotoxicity, can adversely affect brain structures and functions and are linked to neurodegenerative diseases. Despite the essential role of lipids in brain structures and functions, the brain lipidome profile of mammals exposed to MCs remains unexplored, hindering a clear understanding of the neurotoxic effects of MCs and underlying mechanisms. In this study, we performed untargeted lipidomic profiling using ultra-performance liquid chromatography-mass spectrometry (UPLC-MS) on the prefrontal cortex and hippocampus of mice orally exposed to 30 and 300 μg/kg body mass/day of microcystin-leucine arginine (MC-LR) for 180 days to evaluate the impacts of MC-LR on the brain lipidome profile and functions. Our results show that MC-LR resulted in a decline in cognitive parameters, as assessed by the Morris water maze test. Interestingly, apparent neurodegenerative changes were observed in the prefrontal cortex, but not in the hippocampus. Comprehensive lipidomic analyses uncovered profound, region-specific changes in the phospholipid and sphingolipid profile at the levels of lipid subclasses, lipid species, and fatty acyl composition. These changes showed overall decrease trends of lipid content in the prefrontal cortex yet increasing trends in the hippocampus. We identified distinct transcriptional regulations of lipid metabolism and apoptosis by MC-LR in the two regions, which appeared to underlie the neurodegenerative changes. Collectively, this study uncovers region-specific changes in the brain lipidome profile and functions induced by MCs, shedding light on the role of lipid dysfunction in neurotoxicity mechanism of MCs.
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Affiliation(s)
- Jun He
- 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 (UCAS), Beijing 100049, China
| | - Yang 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 (UCAS), Beijing 100049, China
| | - Shiming Dai
- 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 (UCAS), Beijing 100049, China
| | - Feng 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 (UCAS), Beijing 100049, China
| | - Yeke Wang
- 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 (UCAS), Beijing 100049, China
| | - Ting Shi
- 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 (UCAS), Beijing 100049, China
| | - 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 (UCAS), Beijing 100049, China; Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Kunming 650500, China
| | - Ying Liu
- Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Kunming 650500, 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; University of Chinese Academy of Sciences (UCAS), Beijing 100049, 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; University of Chinese Academy of Sciences (UCAS), Beijing 100049, China; Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Kunming 650500, China.
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3
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Nugumanova G, Ponomarev ED, Askarova S, Fasler-Kan E, Barteneva NS. Freshwater Cyanobacterial Toxins, Cyanopeptides and Neurodegenerative Diseases. Toxins (Basel) 2023; 15:toxins15030233. [PMID: 36977124 PMCID: PMC10057253 DOI: 10.3390/toxins15030233] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Revised: 03/13/2023] [Accepted: 03/19/2023] [Indexed: 03/30/2023] Open
Abstract
Cyanobacteria produce a wide range of structurally diverse cyanotoxins and bioactive cyanopeptides in freshwater, marine, and terrestrial ecosystems. The health significance of these metabolites, which include genotoxic- and neurotoxic agents, is confirmed by continued associations between the occurrence of animal and human acute toxic events and, in the long term, by associations between cyanobacteria and neurodegenerative diseases. Major mechanisms related to the neurotoxicity of cyanobacteria compounds include (1) blocking of key proteins and channels; (2) inhibition of essential enzymes in mammalian cells such as protein phosphatases and phosphoprotein phosphatases as well as new molecular targets such as toll-like receptors 4 and 8. One of the widely discussed implicated mechanisms includes a misincorporation of cyanobacterial non-proteogenic amino acids. Recent research provides evidence that non-proteinogenic amino acid BMAA produced by cyanobacteria have multiple effects on translation process and bypasses the proof-reading ability of the aminoacyl-tRNA-synthetase. Aberrant proteins generated by non-canonical translation may be a factor in neuronal death and neurodegeneration. We hypothesize that the production of cyanopeptides and non-canonical amino acids is a more general mechanism, leading to mistranslation, affecting protein homeostasis, and targeting mitochondria in eukaryotic cells. It can be evolutionarily ancient and initially developed to control phytoplankton communities during algal blooms. Outcompeting gut symbiotic microorganisms may lead to dysbiosis, increased gut permeability, a shift in blood-brain-barrier functionality, and eventually, mitochondrial dysfunction in high-energy demanding neurons. A better understanding of the interaction between cyanopeptides metabolism and the nervous system will be crucial to target or to prevent neurodegenerative diseases.
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Affiliation(s)
- Galina Nugumanova
- Department of Biology, School of Sciences and Humanities, Nazarbayev University, Astana 010000, Kazakhstan
| | - Eugene D Ponomarev
- Department of Biology, School of Sciences and Humanities, Nazarbayev University, Astana 010000, Kazakhstan
| | - Sholpan Askarova
- Center for Life Sciences, National Laboratory Astana, Nazarbayev University, Astana 010000, Kazakhstan
| | - Elizaveta Fasler-Kan
- Department of Pediatric Surgery, Children's Hospital, Inselspital Bern, University of Bern, 3010 Bern, Switzerland
| | - Natasha S Barteneva
- Department of Biology, School of Sciences and Humanities, Nazarbayev University, Astana 010000, Kazakhstan
- The Environment & Resource Efficiency Cluster (EREC), Nazarbayev University, Astana 010000, Kazakhstan
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4
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Turco L, Santori N, Buratti FM, Dorne JLCM, Testai E. Congeners-Specific Intestinal Absorption Of Microcystins In An In Vitro 3D Human Intestinal Epithelium: The Role Of Influx/Efflux Transporters. FRONTIERS IN TOXICOLOGY 2022; 4:883063. [PMID: 35990858 PMCID: PMC9388863 DOI: 10.3389/ftox.2022.883063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Accepted: 03/28/2022] [Indexed: 11/18/2022] Open
Abstract
Microcystins constitute a group of over 200 variants and are increasingly considered as emerging toxins in food and feed safety, particularly with regards to sea-food and fish consumption. Toxicity of MCs is congener-specific, being characterised by different acute potencies, likely related to the differential activity of metabolic enzymes and transporters proteins involved in their cellular uptake. However, the active transport of MCs across intestinal membranes has not been fully elucidated. Our results, obtained using a fit for purpose 3D human reconstructed intestinal epithelium, provide new information on the complex mechanisms involved in the absorption of 5 MC variants’: it is indeed characterised by the equilibrium between uptake and extrusion, since the selected congeners are substrates of both influx and efflux proteins. In the range of tested nominal concentrations (10–40 µM) fully representative of relevant exposure scenarios, none of the active tested transporters were saturated. The comparison of permeability (Papp) values of MCs variants highlighted a dose independent relationship for MC-LR, -YR and -RR (Papp x 10–7 ranged from 2.95 to 3.54 cm/s), whereas -LW and–LF showed a dose dependent increase in permeability reaching Papp values which were similar to the other congeners at 40 µM. MC-RR, -LR, -YR show absorption values around 5% of the administered dose. Due to their lipophilicity, MC-LW and -LF were also detected within the cellular compartment. The intestinal uptake was only partially attributable to OATPs, suggesting the involvement of additional transporters. Regarding the efflux proteins, MCs are not P-gp substrates whereas MRP2 and to a lesser extent Breast cancer resistance protein are active in their extrusion. Despite the presence of GST proteins, as an indication of metabolic competence, in the intestinal tissue, MC-conjugates were never detected in our experimental settings.
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Affiliation(s)
- Laura Turco
- Istituto Superiore Di Sanità, Environment & Health Dept, Rome, Italy
- *Correspondence: Laura Turco,
| | - Nicoletta Santori
- Istituto Superiore Di Sanità, Environment & Health Dept, Rome, Italy
| | - Franca M. Buratti
- Istituto Superiore Di Sanità, Environment & Health Dept, Rome, Italy
| | | | - Emanuela Testai
- Istituto Superiore Di Sanità, Environment & Health Dept, Rome, Italy
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5
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LC-MS/MS Validation and Quantification of Cyanotoxins in Algal Food Supplements from the Belgium Market and Their Molecular Origins. Toxins (Basel) 2022; 14:toxins14080513. [PMID: 36006175 PMCID: PMC9415669 DOI: 10.3390/toxins14080513] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 07/19/2022] [Accepted: 07/22/2022] [Indexed: 02/04/2023] Open
Abstract
Food supplements are gaining popularity worldwide. However, harmful natural compounds can contaminate these products. In the case of algae-based products, the presence of toxin-producing cyanobacteria may cause health risks. However, data about the prevalence of algal food supplements on the Belgian market and possible contaminations with cyanotoxins are scarce. Therefore, we optimized and validated a method based on Ultra High Performance Liquid Chromatography-Tandem Mass Spectrometry to quantify eight microcystin congeners and nodularin in algal food supplements. Our analytical method was successfully validated and applied on 35 food supplement samples. Nine out of these samples contained microcystin congeners, of which three exceeded 1 µg g−1, a previously proposed guideline value. Additionally, the mcyE gene was amplified and sequenced in ten products to identify the taxon responsible for the toxin production. For seven out of these ten samples, the mcyE gene could be amplified and associated to Microcystis sp. EFSA and posology consumption data for algal-based food supplements were both combined with our toxin prevalence data to establish different toxin exposure scenarios to assess health risks and propose new guideline values.
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Moura DS, Pestana CJ, Moffat CF, Hui J, Irvine JTS, Edwards C, Lawton LA. Adsorption of cyanotoxins on polypropylene and polyethylene terephthalate: Microplastics as vector of eight microcystin analogues. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2022; 303:119135. [PMID: 35283205 DOI: 10.1016/j.envpol.2022.119135] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Revised: 03/04/2022] [Accepted: 03/09/2022] [Indexed: 05/06/2023]
Abstract
Plastics are utilised globally but are of environmental concern due to their persistence. The global presence of microplastics (particles <5 mm in all dimensions) in freshwater environments is increasingly reported, as has the presence of cyanobacterial toxins, including the microcystins. We elucidated the potential role of microplastics as a vector for eight microcystin analogues. Two sizes of polypropylene (PP) and polyethylene terephthalate (PET) microparticles were evaluated. The median particle size distribution (D50) was 8-28 μm for small particles, and 81-124 μm for large particles. Additionally, microcystin-LR and -LF were evaluated individually using small PP and PET to elucidate the adsorption behaviour in the absence of competition. Microcystin hydrophobicity, polymer material, and particle size were key factors influencing adsorption to the plastic microparticles. The small size PP microparticles demonstrated a high affinity for the 8 microcystin analogues. The proportion of microcystin adsorbed onto the small particles of PP after 48 h contact was between 83 and 100%, depending on the analogue. Of all analogues investigated, only microcystin-LW and -LF adsorbed onto the larger sized PP and PET microparticles. Individually, greater amounts of MC-LF adsorbed onto the small PET (19%) compared to when it was present in the mixture of microcystins (11%). While MC-LR did not adsorb onto small PET microparticles in the mixture, 5% adsorption was observed when individually in contact with small PET microparticles. The results demonstrated that microplastics can adsorb eight different microcystin analogues and that more hydrophobic analogues are more likely to adsorb than less hydrophobic analogues.
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Affiliation(s)
- Diana S Moura
- School of Pharmacy and Life Sciences, Robert Gordon University, Aberdeen, AB10 7GJ, UK.
| | - Carlos J Pestana
- School of Pharmacy and Life Sciences, Robert Gordon University, Aberdeen, AB10 7GJ, UK
| | - Colin F Moffat
- School of Pharmacy and Life Sciences, Robert Gordon University, Aberdeen, AB10 7GJ, UK
| | - Jianing Hui
- School of Chemistry, University of St Andrews, North Haugh, St Andrews, Scotland, KY16 9ST, UK
| | - John T S Irvine
- School of Chemistry, University of St Andrews, North Haugh, St Andrews, Scotland, KY16 9ST, UK
| | - Christine Edwards
- School of Pharmacy and Life Sciences, Robert Gordon University, Aberdeen, AB10 7GJ, UK
| | - Linda A Lawton
- School of Pharmacy and Life Sciences, Robert Gordon University, Aberdeen, AB10 7GJ, UK
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Zhao S, Xu J, Zhang W, Yan W, Li G. Paternal exposure to microcystin-LR triggers developmental neurotoxicity in zebrafish offspring via an epigenetic mechanism involving MAPK pathway. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 792:148437. [PMID: 34153754 DOI: 10.1016/j.scitotenv.2021.148437] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Revised: 05/27/2021] [Accepted: 06/09/2021] [Indexed: 06/13/2023]
Abstract
Microcystin-LR (MCLR) induced impairment to male reproductive system and revealed the effects of transgenerational toxicity on offspring. But very little is known about the inheritance of these effects to offspring and the mechanisms involved. Here, we used methylated DNA immunoprecipitation sequencing (MeDIP-Seq) and microarray to characterize whole-genome DNA methylation and mRNA expression patterns in zebrafish testis after 6-week exposure to 5 and 20 μg/L MCLR. Accompanied with these analyses it revealed that MAPK pathway and ER pathway significantly enriched in zebrafish testes. Apoptosis and testicular damage were also observed in testis. Next, we test the transmission of effects to compare control-father and MCLR exposure-father progenies. DNA methylation analyses (via reduced representation bisulfite sequencing) reveal that the enrichment of differentially methylated regions on neurodevelopment after paternal MCLR exposure. Meanwhile, several genes associated with neurodevelopment were markedly downregulated in zebrafish larvae, and swimming speed was also reduced in the larvae. Interestingly, paternal MCLR exposure also triggered activation the phosphorylation of mitogen-activated protein kinase (MAPK) pathway which is also associated with neurodevelopmental disorders. These results demonstrated the significant effect that paternal MCLR exposure may have on gene-specific DNA methylation patterns in testis. Inherited epigenetic alterations through the germline may be the mechanism leading to developmental neurotoxicity in the offspring.
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Affiliation(s)
- Sujuan Zhao
- School of Public Health, Anhui Medical University, Hefei 230032, China
| | - Jiayi Xu
- School of Public Health, Anhui Medical University, Hefei 230032, China
| | - Weiyun Zhang
- School of Public Health, Anhui Medical University, Hefei 230032, China
| | - Wei Yan
- Institute of Agricultural Quality Standards & Testing Technology, Hubei Academy of Agricultural Sciences, Wuhan 430064, China
| | - Guangyu Li
- College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China.
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8
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Kim W, Kim M, Hong M, Park W. Killing effect of deinoxanthins on cyanobloom-forming Microcystis aeruginosa: Eco-friendly production and specific activity of deinoxanthins. ENVIRONMENTAL RESEARCH 2021; 200:111455. [PMID: 34118245 DOI: 10.1016/j.envres.2021.111455] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Revised: 05/11/2021] [Accepted: 05/29/2021] [Indexed: 06/12/2023]
Abstract
Cyanobacterial blooms caused mainly by Microcystis aeruginosa could be controlled using chemical and biological agents such as H2O2, antagonistic bacteria, and enzymes. Little is known about the possible toxic effects of bacterial membrane pigments on M. aeruginosa cells. Deinococcus metallilatus MA1002 cultured under light increased the production of several carotenoid-like compounds by upregulating two deinoxanthin biosynthesis genes: crtO and cruC. The deinoxanthin compounds were identified using thin-layer chromatography, high-performance liquid chromatography, and liquid chromatography-mass spectrometry. D. metallilatus was cultured with agricultural by-products under light to produce the deinoxanthin compounds. Soybean meal, from six tested agricultural by-products, was selected as the single factor for making an economical medium to produce deinoxanthin compounds. The growth of axenic M. aeruginosa PCC7806, as well as other xenic cyanobacteria such as Cyanobium gracile, Trichormus variabilis, and Dolichospermum circinale, were inhibited by the deinoxanthin compounds. Scanning electron microscopic images showed the complete collapse of M. aeruginosa cells under deinoxanthin treatment, probably due to its interference with cyanobacterial membrane synthesis during cellular elongation. Deinoxanthins appeared to be nontoxic to other non-cyanobacteria such as Acinetobacter, Pseudomonas, Methylobacterium, and Bacillus species, suggesting that it can be a novel candidate for preventing cyanobacterial blooms through its specific activity against cyanobacteria.
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Affiliation(s)
- Wonjae Kim
- Laboratory of Molecular Environmental Microbiology, Department of Environmental Science and Ecological Engineering, Korea University, Seoul, 02841, Republic of Korea
| | - Minkyung Kim
- Laboratory of Molecular Environmental Microbiology, Department of Environmental Science and Ecological Engineering, Korea University, Seoul, 02841, Republic of Korea
| | - Minyoung Hong
- Laboratory of Molecular Environmental Microbiology, Department of Environmental Science and Ecological Engineering, Korea University, Seoul, 02841, Republic of Korea
| | - Woojun Park
- Laboratory of Molecular Environmental Microbiology, Department of Environmental Science and Ecological Engineering, Korea University, Seoul, 02841, Republic of Korea.
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Smit IA, Afzal AM, Allen CHG, Svensson F, Hanser T, Bender A. Systematic Analysis of Protein Targets Associated with Adverse Events of Drugs from Clinical Trials and Postmarketing Reports. Chem Res Toxicol 2020; 34:365-384. [PMID: 33351593 DOI: 10.1021/acs.chemrestox.0c00294] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Adverse drug reactions (ADRs) are undesired effects of medicines that can harm patients and are a significant source of attrition in drug development. ADRs are anticipated by routinely screening drugs against secondary pharmacology protein panels. However, there is still a lack of quantitative information on the links between these off-target proteins and the reporting of ADRs in humans. Here, we present a systematic analysis of associations between measured and predicted in vitro bioactivities of drugs and adverse events (AEs) in humans from two sources of data: the Side Effect Resource, derived from clinical trials, and the Food and Drug Administration Adverse Event Reporting System, derived from postmarketing surveillance. The ratio of a drug's therapeutic unbound plasma concentration over the drug's in vitro potency against a given protein was used to select proteins most likely to be relevant to in vivo effects. In examining individual target bioactivities as predictors of AEs, we found a trade-off between the positive predictive value and the fraction of drugs with AEs that can be detected. However, considering sets of multiple targets for the same AE can help identify a greater fraction of AE-associated drugs. Of the 45 targets with statistically significant associations to AEs, 30 are included on existing safety target panels. The remaining 15 targets include 9 carbonic anhydrases, of which CA5B is significantly associated with cholestatic jaundice. We include the full quantitative data on associations between measured and predicted in vitro bioactivities and AEs in humans in this work, which can be used to make a more informed selection of safety profiling targets.
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Affiliation(s)
- Ines A Smit
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom
| | - Avid M Afzal
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom
| | - Chad H G Allen
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom
| | - Fredrik Svensson
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom
| | - Thierry Hanser
- Lhasa Limited, Granary Wharf House, 2 Canal Wharf, Leeds LS11 5PS, United Kingdom
| | - Andreas Bender
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom
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10
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Schreidah CM, Ratnayake K, Senarath K, Karunarathne A. Microcystins: Biogenesis, Toxicity, Analysis, and Control. Chem Res Toxicol 2020; 33:2225-2246. [PMID: 32614166 DOI: 10.1021/acs.chemrestox.0c00164] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Microcystins are cyclic peptide toxins formed by cyanobacteria. These toxins are recognized for their association with algal blooms, posing a significant threat to ecosystems and drinking water quality. Due to the growing environmental concerns they raise, a comprehensive review on microcystins' genesis, toxicity, and analytical methods for their quantitative determination is outlined. Genes, including the mcyABC cluster, regulate microcystin biogenesis. Bioanalytical experiments have identified key environmental factors, such as temperature and nitrogen availability, that promote microcystin production. Microcystin toxicity is explored based on its modulatory effects on protein phosphatases 1 and 2A in specific tissues and organs. Additionally, biochemical mechanisms of chelation, transportation, resultant oxidative stress, and tumor promotion abilities of microcystins are also discussed. Various analytical methods to separate, detect, and quantify microcystins, including the quantitative real-time polymerase chain reaction, enzyme-linked immunosorbent assay, nuclear magnetic resonance spectroscopy, and chromatographic platforms-linked tandem mass spectrometry (LC-MS) for unequivocal structural identification, are also reviewed. Since control of microcystins in water is of great necessity, both water treatment and mechanisms of abiotic transformation and microbial degradation are also discussed.
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Affiliation(s)
- Celine M Schreidah
- Vagelos College of Physicians and Surgeons, Columbia University, New York, New York 10032, United States
- Department of Chemistry and Biochemistry, University of Toledo, Toledo, Ohio 43606, United States
| | - Kasun Ratnayake
- Department of Chemistry and Biochemistry, University of Toledo, Toledo, Ohio 43606, United States
| | - Kanishka Senarath
- Department of Chemistry and Biochemistry, University of Toledo, Toledo, Ohio 43606, United States
- Department of Chemistry, University of Colombo, Colombo 00300, Sri Lanka
| | - Ajith Karunarathne
- Department of Chemistry and Biochemistry, University of Toledo, Toledo, Ohio 43606, United States
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11
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Di Gioia D, Bozzi Cionci N, Baffoni L, Amoruso A, Pane M, Mogna L, Gaggìa F, Lucenti MA, Bersano E, Cantello R, De Marchi F, Mazzini L. A prospective longitudinal study on the microbiota composition in amyotrophic lateral sclerosis. BMC Med 2020; 18:153. [PMID: 32546239 PMCID: PMC7298784 DOI: 10.1186/s12916-020-01607-9] [Citation(s) in RCA: 73] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Accepted: 04/27/2020] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND A connection between amyotrophic lateral sclerosis (ALS) and altered gut microbiota composition has previously been reported in animal models. This work is the first prospective longitudinal study addressing the microbiota composition in ALS patients and the impact of a probiotic supplementation on the gut microbiota and disease progression. METHODS Fifty patients and 50 matched controls were enrolled. The microbial profile of stool samples from patients and controls was analyzed via PCR-Denaturing Gradient Gel Electrophoresis, and the main microbial groups quantified via qPCR. The whole microbiota was then analyzed via next generation sequencing after amplification of the V3-V4 region of 16S rDNA. Patients were then randomized to receive probiotic treatment or placebo and followed up for 6 months with ALSFRS-R, BMI, and FVC%. RESULTS The results demonstrate that the gut microbiota of ALS patients is characterized by some differences with respect to controls, regardless of the disability degree. Moreover, the gut microbiota composition changes during the course of the disease as demonstrated by the significant decrease in the number of observed operational taxonomic unit during the follow-up. Interestingly, an unbalance between potentially protective microbial groups, such as Bacteroidetes, and other with potential neurotoxic or pro-inflammatory activity, such as Cyanobacteria, has been shown. The 6-month probiotic treatment influenced the gut microbial composition; however, it did not bring the biodiversity of intestinal microbiota of patients closer to that of control subjects and no influence on the progression of the disease measured by ALSFRS-R was demonstrated. CONCLUSIONS Our study poses the bases for larger clinical studies to characterize the microbiota changes as a novel ALS biomarker and to test new microbial strategy to ameliorate the health status of the gut. TRIAL REGISTRATION CE 107/14, approved by the Ethics Committee of the "Maggiore della Carità" University Hospital, Italy.
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Affiliation(s)
- Diana Di Gioia
- Department of Agricultural and Food Sciences, University of Bologna, Viale Fanin 42, Bologna, Italy
| | - Nicole Bozzi Cionci
- Department of Agricultural and Food Sciences, University of Bologna, Viale Fanin 42, Bologna, Italy
| | - Loredana Baffoni
- Department of Agricultural and Food Sciences, University of Bologna, Viale Fanin 42, Bologna, Italy
| | - Angela Amoruso
- BIOLAB RESEARCH srl, via E. Mattei 3, 28100, Novara, Italy
| | - Marco Pane
- BIOLAB RESEARCH srl, via E. Mattei 3, 28100, Novara, Italy
| | - Luca Mogna
- BIOLAB RESEARCH srl, via E. Mattei 3, 28100, Novara, Italy
| | - Francesca Gaggìa
- Department of Agricultural and Food Sciences, University of Bologna, Viale Fanin 42, Bologna, Italy
| | - Maria Ausiliatrice Lucenti
- Department of Neurology and ALS Centre, University of Piemonte Orientale, Maggiore della Carità Hospital, Corso Mazzini 18, 28100, Novara, Italy
| | - Enrica Bersano
- Department of Neurology and ALS Centre, University of Piemonte Orientale, Maggiore della Carità Hospital, Corso Mazzini 18, 28100, Novara, Italy
| | - Roberto Cantello
- Department of Neurology and ALS Centre, University of Piemonte Orientale, Maggiore della Carità Hospital, Corso Mazzini 18, 28100, Novara, Italy
| | - Fabiola De Marchi
- Department of Neurology and ALS Centre, University of Piemonte Orientale, Maggiore della Carità Hospital, Corso Mazzini 18, 28100, Novara, Italy
| | - Letizia Mazzini
- Department of Neurology and ALS Centre, University of Piemonte Orientale, Maggiore della Carità Hospital, Corso Mazzini 18, 28100, Novara, Italy.
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12
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Santori N, Buratti FM, Scardala S, Dorne JLCM, Testai E. In vitro detoxication of microcystins in human samples: variability among variants with different hydrophilicity and structure. Toxicol Lett 2020; 322:131-139. [PMID: 31953209 DOI: 10.1016/j.toxlet.2020.01.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Revised: 01/07/2020] [Accepted: 01/11/2020] [Indexed: 10/25/2022]
Abstract
Cyanotoxins, among which >200 variants of Microcystins (MC), constitute an emerging issue in food safety. Microcystins (MC) toxicity is congener-specific; however, the in vitro inhibition of PP1/PP2A (the key molecular event of MC toxicity) by single MC variants is comparable and MC toxicokinetics seems to be the critical point. Here, the variability in GSH conjugation catalysed by human recombinant enzymes and human hepatic cytosol has been compared between hydrophilic (MC-LR and MC-RR) and hydrophobic (MC-LW, MC-YR and MC-LF) variants, according to measured logPow. In vitro detoxication reaction (spontaneous plus enzymatic) is favored by the variant hydrophilicity, with MC-LF very poorly detoxified. With MC-YR and -LW the spontaneous reaction always gave the major contribution, whereas with MC-LR and -RR the enzymatic reaction became by far predominant when GSH was depleted. Consequently, the well-known GST polymorphisms seems not to be the major driver for potential human variability in susceptibility towards the MC-toxicity, except for MC-RR and -LR when GSH is depleted. Looking at these results and literature data, MC-RR (the least cytotoxic and acutely toxic in rodents) is the more hydrophilic, has the lowest OATP-mediated hepatic uptake and the highest detoxication efficiency. The opposite is true for the most lipophilic MC-LF: once entered in the cells with the highest uptake, it is very poorly detoxified, and resulted as the most toxic in various cell types. MC-dependent TK should be considered in order to estimate the variability in toxicity and to support the use of quantitative in vitro-in vivo extrapolation models of single toxins and their mixtures co-occurring in the environment.
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Affiliation(s)
- Nicoletta Santori
- Istituto Superiore Di Sanità, Environment & Health Dept., Viale Regina Elena, 299, Rome Italy
| | - Franca Maria Buratti
- Istituto Superiore Di Sanità, Environment & Health Dept., Viale Regina Elena, 299, Rome Italy.
| | - Simona Scardala
- Istituto Superiore Di Sanità, Environment & Health Dept., Viale Regina Elena, 299, Rome Italy
| | | | - Emanuela Testai
- Istituto Superiore Di Sanità, Environment & Health Dept., Viale Regina Elena, 299, Rome Italy
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Novel Microcystins from Planktothrix prolifica NIVA-CYA 544 Identified by LC-MS/MS, Functional Group Derivatization and 15N-labeling. Mar Drugs 2019; 17:md17110643. [PMID: 31731697 PMCID: PMC6891653 DOI: 10.3390/md17110643] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Revised: 11/08/2019] [Accepted: 11/09/2019] [Indexed: 12/31/2022] Open
Abstract
Microcystins are cyclic heptapeptides from cyanobacteria that are potent inhibitors of protein phosphatases and are toxic to animals and humans. At present, more than 250 microcystin variants are known, with variants reported for all seven peptide moieties. While d-glutamic acid (d-Glu) is highly-conserved at position-6 of microcystins, there has been only one report of a cyanobacterium (Anabaena) producing microcystins containing l-Glu at the variable 2- and 4-positions. Liquid chromatography–mass spectrometry analyses of extracts from Planktothrix prolifica NIVA-CYA 544 led to the tentative identification of two new Glu-containing microcystins, [d-Asp3]MC-ER (12) and [d-Asp3]MC-EE (13). Structure determination was aided by thiol derivatization of the Mdha7-moiety and esterification of the carboxylic acid groups, while 15N-labeling of the culture and isotopic profile analysis assisted the determination of the number of nitrogen atoms present and the elemental composition of molecular and product-ions. The major microcystin analog in the extracts was [d-Asp3]MC-RR (1). A microcystin with an unprecedented high-molecular-mass (2116 Da) was also detected and tentatively identified as a sulfide-linked conjugate of [d-Asp3]MC-RR (15) by LC–HRMS/MS and sulfide oxidation, together with its sulfoxide (16) produced via autoxidation. Low levels of [d-Asp3]MC-RW (14), [d-Asp3]MC-LR (4), [d-Asp3,Mser7]MC-RR (11), [d-Asp3]MC-RY (17), [d-Asp3]MC-RF (18), [d-Asp3]MC-RR–glutathione conjugate (19), and [d-Asp3]MC-RCit (20), the first reported microcystin containing citrulline, were also identified in the extract, and an oxidized derivative of [d-Asp3]MC-RR and the cysteine conjugate of 1 were partially characterized.
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14
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Kaur G, Fahrner R, Wittmann V, Stieger B, Dietrich DR. Human MRP2 exports MC-LR but not the glutathione conjugate. Chem Biol Interact 2019; 311:108761. [PMID: 31348918 DOI: 10.1016/j.cbi.2019.108761] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Revised: 07/18/2019] [Accepted: 07/22/2019] [Indexed: 01/20/2023]
Abstract
Water contamination by cyanobacterial blooms is a worldwide health hazard to humans as well as livestock. Exposure to Microcystins (MCs), toxins produced by various cyanobacterial or blue green algae found in poorly treated drinking water or contaminated seafood such as fish or prawns are associated with hepatotoxicity, nephropathy and neurotoxicity and in extreme cases, death in humans. MC congeners, currently >240 known, differ dramatically in their uptake kinetics, i.e. their uptake via OATP1B1 and OATP1B3, in OATP overexpressing human HEK293 cells and primary human hepatocytes. It is thus likely that MC congeners will also differ with respect to the cellular efflux of the parent and conjugated congeners, e.g. via MRPs, MDRs, BCRP or BSEP. Consequently, the role and kinetics of different human efflux transporters - MRP, MDR, BCRP and BSEP in MC efflux was studied using insect membrane vesicles overexpressing the human transporters of interest. Of the efflux transporters investigated, MRP2 displayed MC transport. Michaelis-Menten kinetics displayed mild co-operativity and thus allosteric behavior of MRP2. MC transport by MRP2 was MC congener-specific, whereby MC-LF was transported more rapidly than MC-LR and -RR. Other human transporters (BCRP, BSEP, MRP1,3,5, MDR1) tested in this study did not exhibit interaction with MC. Although MRP2 showed specific MC transport, the MC-LR-GSH conjugate, was not transported suggesting the involvement of other transporters than MRP2 for the conjugate efflux.
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Affiliation(s)
- Gurjot Kaur
- Human and Environmental Toxicology, University of Konstanz, 78457, Konstanz, Germany; School of Pharmaceutical Sciences, Shoolini University, Solan, 173212, India.
| | - Raphael Fahrner
- Department of Chemistry, University of Konstanz, 78457, Konstanz, Germany.
| | - Valentin Wittmann
- Department of Chemistry, University of Konstanz, 78457, Konstanz, Germany.
| | - Bruno Stieger
- Department of Clinical Pharmacology and Toxicology, University Hospital, 8091, Zurich, Switzerland.
| | - Daniel Reto Dietrich
- Human and Environmental Toxicology, University of Konstanz, 78457, Konstanz, Germany.
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15
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Simultaneous Detection of 14 Microcystin Congeners from Tissue Samples Using UPLC- ESI-MS/MS and Two Different Deuterated Synthetic Microcystins as Internal Standards. Toxins (Basel) 2019; 11:toxins11070388. [PMID: 31269739 PMCID: PMC6669509 DOI: 10.3390/toxins11070388] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Revised: 06/21/2019] [Accepted: 06/28/2019] [Indexed: 02/02/2023] Open
Abstract
Cyanobacterial microcystins (MCs), potent serine/threonine-phosphatase inhibitors, pose an increasing threat to humans. Current detection methods are optimised for water matrices with only a few MC congeners simultaneously detected. However, as MC congeners are known to differ in their toxicity, methods are needed that simultaneously quantify the congeners present, thus allowing for summary hazard and risk assessment. Moreover, detection of MCs should be expanded to complex matrices, e.g., blood and tissue samples, to verify in situ MC concentrations, thus providing for improved exposure assessment and hazard interpretation. To achieve this, we applied two synthetic deuterated MC standards and optimised the tissue extraction protocol for the simultaneous detection of 14 MC congeners in a single ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) run. This procedure was validated using plasma and liver homogenates of mice (male and female) spiked with deuterated MC standards. For proof of concept, tissue and plasma samples from mice i.p. injected with MC-LR and MC-LF were analysed. While MC-LF was detected in all tissue samples of both sexes, detection of MC-LR was restricted to liver samples of male mice, suggesting different toxicokinetics in males, e.g., transport, conjugation or protein binding. Thus, deconjugation/-proteinisation steps should be employed to improve detection of bound MC.
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16
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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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17
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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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18
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Díez-Quijada L, Prieto AI, Guzmán-Guillén R, Jos A, Cameán AM. Occurrence and toxicity of microcystin congeners other than MC-LR and MC-RR: A review. Food Chem Toxicol 2018; 125:106-132. [PMID: 30597222 DOI: 10.1016/j.fct.2018.12.042] [Citation(s) in RCA: 88] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Revised: 11/29/2018] [Accepted: 12/25/2018] [Indexed: 12/11/2022]
Abstract
The occurrence of cyanobacterial toxins is being increasingly reported. This is a reason for concern as they can induce toxic effects both in humans and in the environment. Among them, microcystins (MCs) are the best described and most diverse group of cyanobacterial toxins, and MC-LR and MC-RR are the congeners most widely investigated. However, the number of MC variants has also increased in recent years. Some of these minority variants have been shown to have a different toxicokinetic and toxicodynamic profile, but research focused on them is still limited. Moreover, in some water bodies these minority variants can be the predominant toxins. Nonetheless, MC-LR is the only one used for risk evaluation purposes at present. In order to contribute to more realistic risk assessments in the future, the aim of this review was to compile the available information in the scientific literature regarding the occurrence and concentration of minority MCs in water and food samples, and their toxic effects. The data retrieved demonstrate the congener-specific toxicity of MCs, as well as many data gaps in relation to analytical or mechanistic aspects, among others. Therefore, further research is needed to improve the toxicological characterization of these toxins and the exposure scenarios.
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Affiliation(s)
- Leticia Díez-Quijada
- Area of Toxicology, Faculty of Pharmacy, Universidad de Sevilla, C/Profesor García González 2, 41012, Seville, Spain
| | - Ana I Prieto
- Area of Toxicology, Faculty of Pharmacy, Universidad de Sevilla, C/Profesor García González 2, 41012, Seville, Spain
| | - Remedios Guzmán-Guillén
- Area of Toxicology, Faculty of Pharmacy, Universidad de Sevilla, C/Profesor García González 2, 41012, Seville, Spain
| | - Angeles Jos
- Area of Toxicology, Faculty of Pharmacy, Universidad de Sevilla, C/Profesor García González 2, 41012, Seville, Spain.
| | - Ana M Cameán
- Area of Toxicology, Faculty of Pharmacy, Universidad de Sevilla, C/Profesor García González 2, 41012, Seville, Spain
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19
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Microcystin-LR-Triggered Neuronal Toxicity in Whitefish Does Not Involve MiR124-3p. Neurotox Res 2018; 35:29-40. [PMID: 29882005 PMCID: PMC6313356 DOI: 10.1007/s12640-018-9920-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2018] [Revised: 05/28/2018] [Accepted: 05/30/2018] [Indexed: 02/07/2023]
Abstract
Microcystin-LR (MC-LR) is a potent hepatotoxin that has also been pointed out of causing neurotoxicity, but the exact mechanisms of action still remain ambiguous and need to be elucidated. Data from studies on mammals show that pathology of astrocyte cells points to perturbations of microRNA signaling. Glial fibrillary acidic protein (GFAP), a neuronal cell/astrocyte-specific protein, and a microRNA-124-3p (MiR124-3p) are among putative triggers and regulators of neuronal cell/astrocyte reactivity. In the present study on whitefish (Coregonus lavaretus), we found that gfap mRNA contains a putative target site for MIR124-3p, to potentially affect its expression changes. qPCR expression study of gfap:MiR124-3p pair in the midbrain of juvenile whitefish, during 28 days of exposure to a repeated subacute dose of MC-LR (100 μg kg−1 body mass), showed marginally significant up-regulation of gfap only on the 7th day of exposure period which suggests neuronal toxicity. During the whole exposure period, neither midbrain nor blood plasma levels of MiR124-3p were changed. Furthermore, double luciferase gene reporter assay confirmed the lack of MiR124-3p involvement in mediating control over gfap mRNA expression. These data show that, although MC-LR may trigger neuronal toxicity in whitefish, this does not involve MiR124-3p in response to the treatment.
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20
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Toxic Cyanobacteria in Svalbard: Chemical Diversity of Microcystins Detected Using a Liquid Chromatography Mass Spectrometry Precursor Ion Screening Method. Toxins (Basel) 2018; 10:toxins10040147. [PMID: 29614044 PMCID: PMC5923313 DOI: 10.3390/toxins10040147] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Revised: 03/27/2018] [Accepted: 03/29/2018] [Indexed: 11/16/2022] Open
Abstract
Cyanobacteria synthesize a large variety of secondary metabolites including toxins. Microcystins (MCs) with hepato- and neurotoxic potential are well studied in bloom-forming planktonic species of temperate and tropical regions. Cyanobacterial biofilms thriving in the polar regions have recently emerged as a rich source for cyanobacterial secondary metabolites including previously undescribed congeners of microcystin. However, detection and detailed identification of these compounds is difficult due to unusual sample matrices and structural congeners produced. We here report a time-efficient liquid chromatography-mass spectrometry (LC-MS) precursor ion screening method that facilitates microcystin detection and identification. We applied this method to detect six different MC congeners in 8 out of 26 microbial mat samples of the Svalbard Archipelago in the Arctic. The congeners, of which [Asp3, ADMAdda5, Dhb7] MC-LR was most abundant, were similar to those reported in other polar habitats. Microcystins were also determined using an Adda-specific enzyme-linked immunosorbent assay (Adda-ELISA). Nostoc sp. was identified as a putative toxin producer using molecular methods that targeted 16S rRNA genes and genes involved in microcystin production. The mcy genes detected showed highest similarities to other Arctic or Antarctic sequences. The LC-MS precursor ion screening method could be useful for microcystin detection in unusual matrices such as benthic biofilms or lichen.
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21
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Proteomic evidences for microcystin-RR-induced toxicological alterations in mice liver. Sci Rep 2018; 8:1310. [PMID: 29358693 PMCID: PMC5778043 DOI: 10.1038/s41598-018-19299-w] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Accepted: 12/29/2017] [Indexed: 02/07/2023] Open
Abstract
This study deals with the isolation and purification of an important variant of microcystins namely microcystin-RR (MCYST-RR) from Microcystis aeruginosa and reports its effects on mice liver protein profile and cellular functions. Protein profiling by 2-dimensional gel electrophoresis revealed changes in the number and accumulation of protein spots in liver of mice treated with different concentrations of MCYST-RR. Untreated (control) mice liver showed 368 protein spots while the number was 355, 348 and 332 in liver of mice treated with 200, 300 and 400 µg kg body wt−1 of MCYST-RR respectively. Altogether 102, 97, and 92 spots were differentially up-accumulated and 93, 91, and 87 spots were down- accumulated respectively with the treatment of 200, 300, 400 µg kg body wt−1. Eighteen differentially accumulated proteins present in all the four conditions were identified by MALDI-TOF MS. Of these eighteen proteins, 12 appeared to be involved in apoptosis/toxicological manifestations. Pathway analysis by Reactome and PANTHER database also mapped the identified proteins to programmed cell death/apoptosis clade. That MCYST-RR induces apoptosis in liver tissues was also confirmed by DNA fragmentation assay. Results of this study elucidate the proteomic basis for the hepatotoxicity of MCYST-RR which is otherwise poorly understood till date.
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22
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Funari E, Manganelli M, Buratti FM, Testai E. Cyanobacteria blooms in water: Italian guidelines to assess and manage the risk associated to bathing and recreational activities. THE SCIENCE OF THE TOTAL ENVIRONMENT 2017; 598:867-880. [PMID: 28458204 DOI: 10.1016/j.scitotenv.2017.03.232] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Revised: 03/23/2017] [Accepted: 03/25/2017] [Indexed: 06/07/2023]
Abstract
Cyanobacteria thrive in many aquatic environments, where they can produce cyanotoxins with different toxicological profile. Anthropic pressure and climate changes are causing the expansion in terms of time and space of their blooms, increasing the concerns for human health in several exposure scenarios. Here the update of the Italian guidelines for the management of cyanobacterial blooms in bathing water is presented. A risk-based approach has been developed according to the current scientific knowledge on cyanobacteria distribution in the Italian Lakes and on chemical, toxicological and epidemiological aspects of different cyanotoxins, summarized in the first part of the paper. Oral, dermal and inhalation exposure to cyanotoxins, during recreational activities, are individually examined, to develop a framework of thresholds and actions aimed at preventing harmful effects for bathers. Guidelines, also by comparing international guidance values and/or guidelines, provide criteria to plan environmental monitoring activities, health surveillance and public communication systems. Finally the still important scientific gaps and research needs are highlighted.
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Affiliation(s)
- Enzo Funari
- Istituto Superiore di Sanità, Dept. of Environment and Health, Viale Regina Elena 299, 00161 Rome, Italy.
| | - Maura Manganelli
- Istituto Superiore di Sanità, Dept. of Environment and Health, Viale Regina Elena 299, 00161 Rome, Italy.
| | - Franca M Buratti
- Istituto Superiore di Sanità, Dept. of Environment and Health, Viale Regina Elena 299, 00161 Rome, Italy.
| | - Emanuela Testai
- Istituto Superiore di Sanità, Dept. of Environment and Health, Viale Regina Elena 299, 00161 Rome, Italy.
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23
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Moon BR, Kim TK, Kim MK, Choi J, Zoh KD. Degradation mechanisms of Microcystin-LR during UV-B photolysis and UV/H 2O 2 processes: Byproducts and pathways. CHEMOSPHERE 2017; 185:1039-1047. [PMID: 28764099 DOI: 10.1016/j.chemosphere.2017.07.104] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Revised: 07/03/2017] [Accepted: 07/18/2017] [Indexed: 06/07/2023]
Abstract
The removal and degradation pathways of microcystin-LR (MC-LR, [M+H]+ = 995.6) in UV-B photolysis and UV-B/H2O2 processes were examined using liquid chromatography-tandem mass spectrometry. The UV/H2O2 process was more efficient than UV-B photolysis for MC-LR removal. Eight by-products were newly identified in the UV-B photolysis ([M+H]+ = 414.3, 417.3, 709.6, 428.9, 608.6, 847.5, 807.4, and 823.6), and eleven by-products were identified in the UV-B/H2O2 process ([M+H]+ = 707.4, 414.7, 429.3, 445.3, 608.6, 1052.0, 313.4, 823.6, 357.3, 245.2, and 805.7). Most of the MC-LR by-products had lower [M+H]+ values than the MC-LR itself during both processes, except for the [M+H]+ value of 1052.0 during UV-B photolysis. Based on identified by-products and peak area patterns, we proposed potential degradation pathways during the two processes. Bond cleavage and intramolecular electron rearrangement by electron pair in the nitrogen atom were the major reactions during UV-B photolysis and UV-B/H2O2 processes, and hydroxylation by OH radical and the adduct formation reaction between the produced by-products were identified as additional pathways during the UV-B/H2O2 process. Meanwhile, the degradation by-products identified from MC-LR during UV-B/H2O2 process can be further degraded by increasing H2O2 dose.
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Affiliation(s)
- Bo-Ram Moon
- Department of Environmental Health Sciences, School of Public Health, Seoul National University, Seoul 08826, South Korea
| | - Tae-Kyoung Kim
- Department of Environmental Health Sciences, School of Public Health, Seoul National University, Seoul 08826, South Korea
| | - Moon-Kyung Kim
- Institute of Health & Environment, Seoul National University, Seoul 08826, South Korea
| | - Jaewon Choi
- Water Quality Research Center, K-water, Daejeon 34350, South Korea
| | - Kyung-Duk Zoh
- Department of Environmental Health Sciences, School of Public Health, Seoul National University, Seoul 08826, South Korea; Institute of Health & Environment, Seoul National University, Seoul 08826, South Korea.
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Mello FD, Braidy N, Marçal H, Guillemin G, Nabavi SM, Neilan BA. Mechanisms and Effects Posed by Neurotoxic Products of Cyanobacteria/Microbial Eukaryotes/Dinoflagellates in Algae Blooms: a Review. Neurotox Res 2017; 33:153-167. [PMID: 28836116 DOI: 10.1007/s12640-017-9780-3] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Revised: 06/28/2017] [Accepted: 07/05/2017] [Indexed: 12/12/2022]
Abstract
Environmental toxins produced by cyanobacteria and dinoflagellates have increasingly become a public health concern due to their ability to damage several tissues in humans. In particular, emerging evidence has called attention to the neurodegenerative effects of the cyanobacterial toxin β-N-methylamino-L-alanine (BMAA). Furthermore, other toxins such as anatoxin, saxitoxin, microcystin, nodularin and ciguatoxin also have a different range of effects on human tissues, including hepatotoxicity, neurotoxicity and gastrointestinal irritation. However, the vast majority of known environmental toxins have not yet been examined in the context of neurodegenerative disease. This review aims to investigate whether neurotoxic mechanisms can be demonstrated in all aforementioned toxins, and whether there exists a link to neurodegeneration. Management of toxin exposure and potential neuroprotective compounds is also discussed. Collectively, all aforementioned microbial toxins are likely to exert some form of neuronal damage, with many of their modes of action consistent with neurodegeneration. This is important in advancing our current understanding of the cytotoxic potential of environmental toxins upon human brain function, particularly in the context of age-related neurodegenerative disease.
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Affiliation(s)
- Fiona D Mello
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, NSW, 2052, Australia
| | - Nady Braidy
- Centre for Healthy Brain Ageing, School of Psychiatry, Faculty of Medicine, The University of New South Wales, Sydney, Australia
| | - Helder Marçal
- Graduate School of Biomedical Engineering, Faculty of Engineering, The University of New South Wales, Sydney, NSW, 2052, Australia
| | - Gilles Guillemin
- Neuropharmacology group, MND and Neurodegenerative diseases Research Centre, Macquarie University, Sydney, NSW, Australia
| | - Seyed Mohammad Nabavi
- Applied Biotechnology Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran
| | - Brett A Neilan
- School of Environmental and Life Sciences, The University of Newcastle, Callaghan, NSW, 2308, Australia.
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McLellan NL, Manderville RA. Toxic mechanisms of microcystins in mammals. Toxicol Res (Camb) 2017; 6:391-405. [PMID: 30090507 PMCID: PMC6060792 DOI: 10.1039/c7tx00043j] [Citation(s) in RCA: 104] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Accepted: 04/21/2017] [Indexed: 01/08/2023] Open
Abstract
Microcystins, such as microcystin-leucine arginine (MC-LR), are some of the most toxic and prevalent cyanotoxins produced by cyanobacteria in freshwater and saltwater algal blooms worldwide. Acute and chronic exposures to microcystins are primarily known to cause hepatotoxicity; cellular damage and genotoxicity within mammalian livers. However, in vivo studies indicate that similar damage may occur in other mammalian organs and tissues, such as the kidney, heart, reproductive systems, and lungs - particularly following chronic low-dose exposures. Mechanisms of toxicity of mycrocystins are reviewed herein; including cellular uptake, interaction with protein phosphatases PP1 and PP2A, cytoskeletal effects, formation of oxidative stress and induction of apoptosis. In general, the mode of action of toxicity by MCs in mammalian organs are similar to those that have been observed in liver tissues. A comprehensive understanding of the toxic mechanisms of microcystins in mammalian tissues and organs will assist in the development of risk assessment approaches to public health protection strategies and the development of robust drinking water policies.
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Affiliation(s)
- Nicole L McLellan
- School of Environmental Sciences , University of Guelph , Guelph , Ontario N1G 2W1 , Canada
| | - Richard A Manderville
- Department of Chemistry and Toxicology , University of Guelph , Guelph , Ontario N1G 2W1 , Canada . ; ; Tel: +1-519-824-4120, x53963
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Altaner S, Puddick J, Wood SA, Dietrich DR. Adsorption of Ten Microcystin Congeners to Common Laboratory-Ware Is Solvent and Surface Dependent. Toxins (Basel) 2017; 9:toxins9040129. [PMID: 28383495 PMCID: PMC5408203 DOI: 10.3390/toxins9040129] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Revised: 03/23/2017] [Accepted: 03/31/2017] [Indexed: 11/21/2022] Open
Abstract
Cyanobacteria can produce heptapetides called microcystins (MC) which are harmful to humans due to their ability to inhibit cellular protein phosphatases. Quantitation of these toxins can be hampered by their adsorption to common laboratory-ware during sample processing and analysis. Because of their structural diversity (>100 congeners) and different physico-chemical properties, they vary in their adsorption to surfaces. In this study, the adsorption of ten different MC congeners (encompassing non-arginated to doubly-arginated congeners) to common laboratory-ware was assessed using different solvent combinations. Sample handling steps were mimicked with glass and polypropylene pipettes and vials with increasing methanol concentrations at two pH levels, before analysis by liquid chromatography-tandem mass spectrometry. We demonstrated that MC adsorb to polypropylene surfaces irrespective of pH. After eight successive pipet actions using polypropylene tips ca. 20% of the MC were lost to the surface material, which increased to 25%–40% when solutions were acidified. The observed loss was alleviated by changing the methanol (MeOH) concentration in the final solvent. The required MeOH concentration varied depending on which congener was present. Microcystins only adsorbed to glass pipettes (loss up to 30% after eight pipet actions) when in acidified aqueous solutions. The latter appeared largely dependent on the presence of ionizable groups, such as arginine residues.
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Affiliation(s)
- Stefan Altaner
- Human and Environmental Toxicology, University of Konstanz, P.O. Box 662, 78457 Konstanz, Germany.
| | | | - Susanna A Wood
- Environmental Research Institute, University of Waikato, Private Bag 3105, Hamilton 3240, New Zealand.
| | - Daniel R Dietrich
- Human and Environmental Toxicology, University of Konstanz, P.O. Box 662, 78457 Konstanz, Germany.
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Expression analysis of microRNAs and mRNAs in ovarian granulosa cells after microcystin-LR exposure. Toxicon 2017; 129:11-19. [PMID: 28161121 DOI: 10.1016/j.toxicon.2017.01.022] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Revised: 01/23/2017] [Accepted: 01/30/2017] [Indexed: 12/25/2022]
Abstract
Microcystin is a cyclic heptapeptide compounds which could cause female mammals' reproductive toxicity. Ovarian granulosa cells (GCs) are essential for the growth and development of follicles. In this study, after mouse granulosa cells (mGCs) treated with microcystin-LR (MC-LR) for 48 h, microRNAs (miRNAs) and mRNAs microarray technology were adopted to detect the expression of miRNAs and mRNAs. The results showed that 125 miRNAs and 283 mRNAs changed significantly, including 50 miRNAs down-regulated (fold change < -1.2), 75 miRNAs up-regulated (fold change > 1.2), 162 mRNAs down-regulated (fold change < -1.15) and 121 mRNAs up-regulated (fold change > 1.15) in treated group compared with the control group. Functional analysis showed that significant changed miRNAs and mRNAs are mainly involved in proliferation, apoptosis, immunity, metabolism and other biological processes of mGCs. By KEGG pathways analysis, we found that differentially expressed miRNAs and mRNAs mainly participated in apoptosis, formation of cancer, proliferation, production of hormones and other related signal pathways. miRNA-gene network analysis indicated that miR-29b-3p, miR-29a-3p, miR-29c-3p, miR-1906, miR-182-5p, growth factor receptor bound protein 2-associated protein 2 (Gab2), FBJ osteosarcoma oncogene (Fos), insulin-like growth factor 1 (Igf1), mannosidase 1, alpha (Man1a) are key miRNAs and genes. The microarray results were validated by real-time fluorescent quantitative PCR (qRT-PCR).
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28
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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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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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30
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Takser L, Benachour N, Husk B, Cabana H, Gris D. Cyanotoxins at low doses induce apoptosis and inflammatory effects in murine brain cells: Potential implications for neurodegenerative diseases. Toxicol Rep 2016; 3:180-189. [PMID: 28959538 PMCID: PMC5615428 DOI: 10.1016/j.toxrep.2015.12.008] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2015] [Revised: 12/17/2015] [Accepted: 12/24/2015] [Indexed: 11/25/2022] Open
Abstract
Cyanotoxins have been shown to be highly toxic for mammalian cells, including brain cells. However, little is known about their effect on inflammatory pathways. This study investigated whether mammalian brain and immune cells can be a target of certain cyanotoxins, at doses approximating those in the guideline levels for drinking water, either alone or in mixtures. We examined the effects on cellular viability, apoptosis and inflammation signalling of several toxins on murine macrophage-like RAW264.7, microglial BV-2 and neuroblastoma N2a cell lines. We tested cylindrospermopsin (CYN), microcystin-LR (MC-LR), and anatoxin-a (ATX-a), individually as well as their mixture. In addition, we studied the neurotoxins β-N-methylamino-l-alanine (BMAA) and its isomer 2,4-diaminobutyric acid (DAB), as well as the mixture of both. Cellular viability was determined by the MTT assay. Apoptosis induction was assessed by measuring the activation of caspases 3/7. Cell death and inflammation are the hallmarks of neurodegenerative diseases. Thus, our final step was to quantify the expression of a major proinflammatory cytokine TNF-α by ELISA. Our results show that CYN, MC-LR and ATX-a, but not BMAA and DAB, at low doses, especially when present in a mixture at threefold less concentrations than individual compounds are 3–15 times more potent at inducing apoptosis and inflammation. Our results suggest that common cyanotoxins at low doses have a potential to induce inflammation and apoptosis in immune and brain cells. Further research of the neuroinflammatory effects of these compounds in vivo is needed to improve safety limit levels for cyanotoxins in drinking water and food.
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Affiliation(s)
- Larissa Takser
- Department of Pediatrics, Faculty of Medicine and Health Sciences, University of Sherbrooke, Sherbrooke, J1H 5N4 Quebec, Canada
| | - Nora Benachour
- Department of Pediatrics, Faculty of Medicine and Health Sciences, University of Sherbrooke, Sherbrooke, J1H 5N4 Quebec, Canada
| | - Barry Husk
- BlueLeaf Inc., 310 Chapleau Street, Drummondville, J2B 5E9 Quebec, Canada
| | - Hubert Cabana
- Environmental Engineering Laboratory, Department of Civil Engineering, University of Sherbrooke, Sherbrooke, J1K 2R1 Quebec, Canada
| | - Denis Gris
- Department of Pediatrics, Faculty of Medicine and Health Sciences, University of Sherbrooke, Sherbrooke, J1H 5N4 Quebec, Canada
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31
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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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32
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Wu J, Yuan M, Song Y, Sun F, Han X. MC-LR Exposure Leads to Subfertility of Female Mice and Induces Oxidative Stress in Granulosa Cells. Toxins (Basel) 2015; 7:5212-23. [PMID: 26633508 PMCID: PMC4690122 DOI: 10.3390/toxins7124872] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Revised: 11/17/2015] [Accepted: 11/23/2015] [Indexed: 01/04/2023] Open
Abstract
Health risk of human exposure to microcystin-leucine arginine (MC-LR) has aroused more and more attention over the past few decades. In the present study, MC-LR was orally administered to female mice at 0, 1, 10 and 40 μg/L for three and six months. We found that chronic exposure to MC-LR at environmental levels could stimulate follicle atresia and lead to decreased developmental follicles, accompanied by a reduction of gonadosomatic index (GSI). In line with the irregular gonadal hormone level and estrus cycles, subfertility of female mice was also confirmed by analyzing numbers of litters and pups. The in vitro study suggested that granulosa cells could uptake MC-LR and should be the target of the toxicant. Oxidative stress in granulose cells induced by MC-LR promoted follicle atresia and eventually leads to female subfertility.
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Affiliation(s)
- Jiang Wu
- Immunology and Reproduction Biology Laboratory and State Key Laboratory of Analytical Chemistry for Life Science, Medical School, Nanjing University, Nanjing 210093, Jiangsu, China.
- Jiangsu Key Laboratory of Molecular Medicine, Nanjing University, Nanjing 210093, Jiangsu, China.
| | - Mingming Yuan
- Immunology and Reproduction Biology Laboratory and State Key Laboratory of Analytical Chemistry for Life Science, Medical School, Nanjing University, Nanjing 210093, Jiangsu, China.
- Jiangsu Key Laboratory of Molecular Medicine, Nanjing University, Nanjing 210093, Jiangsu, China.
| | - Yuefeng Song
- Immunology and Reproduction Biology Laboratory and State Key Laboratory of Analytical Chemistry for Life Science, Medical School, Nanjing University, Nanjing 210093, Jiangsu, China.
- Jiangsu Key Laboratory of Molecular Medicine, Nanjing University, Nanjing 210093, Jiangsu, China.
| | - Feng Sun
- Immunology and Reproduction Biology Laboratory and State Key Laboratory of Analytical Chemistry for Life Science, Medical School, Nanjing University, Nanjing 210093, Jiangsu, China.
- Jiangsu Key Laboratory of Molecular Medicine, Nanjing University, Nanjing 210093, Jiangsu, China.
| | - Xiaodong Han
- Immunology and Reproduction Biology Laboratory and State Key Laboratory of Analytical Chemistry for Life Science, Medical School, Nanjing University, Nanjing 210093, Jiangsu, China.
- Jiangsu Key Laboratory of Molecular Medicine, Nanjing University, Nanjing 210093, Jiangsu, China.
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Cai F, Liu J, Li C, Wang J. Intracellular Calcium Plays a Critical Role in the Microcystin-LR-Elicited Neurotoxicity Through PLC/IP3 Pathway. Int J Toxicol 2015; 34:551-8. [PMID: 26395499 DOI: 10.1177/1091581815606352] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Neurotoxicity of microcystin-leucine-arginine (MCLR) has been widely reported. However, the mechanism is not fully understood. Using primary hippocampal neurons, we tested the hypothesis that MCLR-triggered activation in intracellular free calcium concentration ([Ca(2+)](i)) induces the death of neurons. Microcystin-leucine-arginine inhibited cell viability at a range of 0.1 to 30 μmol/L and caused a dose-dependent increase in [Ca(2+)](i). This increase in [Ca(2+)](i) was observed in Ca(2+)-free media and blocked by an endoplasmic reticulum Ca(2+) pump inhibitor, suggesting intracellular Ca(2+) release. Moreover, pretreatment of hippocampal neurons with intracellular Ca(2+) chelator (O,O'-bis (2-aminophenyl) ethyleneglycol-N,N,N',N'-tetraacetic acid, tetraacetoxy-methyl ester) and inositol 1,4,5-trisphosphate receptor antagonist (2-aminoethoxydiphenyl borate) could block both the Ca(2+) mobilization and the neuronal death following MCLR exposure. In contrast, the ryanodine receptor inhibitor (dantrolene) did not ameliorate the effect of MCLR. In conclusion, MCLR disrupts [Ca(2+)](i) homeostasis in neurons by releasing Ca(2+) from intracellular stores, and this increase in [Ca(2+)](i) may be a key determinant in the mechanism underlying MCLR-induced neurotoxicity.
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Affiliation(s)
- Fei Cai
- Department of Pharmacology, Hubei University of Science and Technology, Xianning, China
| | - Jue Liu
- Department of Pharmacy, The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Cairong Li
- Hubei Province Key Laboratory on Cardiovascular, Cerebrovascular, and Metabolic Disorders, Hubei University of Science and Technology, Xianning, Hubei, China
| | - Jianghua Wang
- Fisheries College, Huazhong Agricultural University, Wuhan, China
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Zustiak SP, Dadhwal S, Medina C, Steczina S, Chehreghanianzabi Y, Ashraf A, Asuri P. Three-dimensional matrix stiffness and adhesive ligands affect cancer cell response to toxins. Biotechnol Bioeng 2015; 113:443-52. [DOI: 10.1002/bit.25709] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Revised: 06/15/2015] [Accepted: 07/08/2015] [Indexed: 02/06/2023]
Affiliation(s)
| | - Smritee Dadhwal
- Department of Bioengineering; Santa Clara University; Santa Clara California
| | - Carlos Medina
- Department of Bioengineering; Santa Clara University; Santa Clara California
| | - Sonette Steczina
- Department of Bioengineering; Santa Clara University; Santa Clara California
| | | | - Anisa Ashraf
- Department of Biomedical Engineering; Saint Louis University; St. Louis Missouri
| | - Prashanth Asuri
- Department of Bioengineering; Santa Clara University; Santa Clara California
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Huang X, Chen L, Liu W, Qiao Q, Wu K, Wen J, Huang C, Tang R, Zhang X. Involvement of oxidative stress and cytoskeletal disruption in microcystin-induced apoptosis in CIK cells. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2015; 165:41-50. [PMID: 26022555 DOI: 10.1016/j.aquatox.2015.05.009] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Revised: 05/08/2015] [Accepted: 05/10/2015] [Indexed: 06/04/2023]
Abstract
The outbreak of cyanobacterial blooms induces the production and release of microcystins (MCs) into water, representing a health hazard to aquatic organisms and even humans. Some recent studies have suggested that kidney is another important target organ of MCs except liver, however, the potential toxicity mechanisms are still unclear. In this study, we first investigated the collaborative effect of oxidative stress and cytoskeletal disruption in microcystin-induced apoptosis in CIK (Ctenopharyngodon idellus kidney) cells in vitro. CIK cells were treated with 0, 1, 10, and 100μg/L microcystin-LR (MC-LR) for 24 and 48h. Cell viability was increased by MC-LR in 1μg/L group, while decreased in 100μg/L group at 48h. Cell cycle assay showed that 1 and 10μg/L MC-LR induced cell cycle through G1 into S and G2/M phases, while 100μg/L MC-LR reduced G2/M phase population. MC-LR markedly induced apoptosis in 10 and 100μg/L groups. Elevated reactive oxygen species (ROS) production, increased malondialdehyde (MDA) contents, decreased glutathione (GSH) levels, and modulated antioxidant enzymes including catalase (CAT) and superoxide dismutase (SOD) were observed in CIK cells exposed to MC-LR. These alterations were more pronounced at higher doses (10 and 100μg/L), indicating that oxidative stress was induced by MC-LR. Laser scanning confocal microscope observation showed aggregation and collapse of microfilaments (MFs) and microtubules (MTs) in CIK cells, and even loss of some cytoskeleton structure. Moreover, transcriptional changes of cytoskeletal genes (β-actin, lc3a, and keratin) were also determined, which have a high probability with cytoskeleton structure damage. Our data suggest that oxidative stress and cytoskeletal disruption may interact with each other and jointly lead to apoptosis and renal toxicity induced by MCs.
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Affiliation(s)
- Xiao Huang
- College of Fisheries, Huazhong Agricultural University, Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan 430070, China
| | - 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
| | - Wanjing Liu
- College of Fisheries, Huazhong Agricultural University, Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan 430070, China
| | - Qin Qiao
- College of Fisheries, Huazhong Agricultural University, Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan 430070, China
| | - Kang Wu
- College of Fisheries, Huazhong Agricultural University, Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan 430070, China
| | - Jing Wen
- College of Fisheries, Huazhong Agricultural University, Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan 430070, China
| | - Cuihong Huang
- College of Fisheries, Huazhong Agricultural University, Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan 430070, China
| | - Rong Tang
- College of Fisheries, Huazhong Agricultural University, Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan 430070, China
| | - Xuezhen Zhang
- College of Fisheries, Huazhong Agricultural University, Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan 430070, China.
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36
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Bautista AC, Moore CE, Lin Y, Cline MG, Benitah N, Puschner B. Hepatopathy following consumption of a commercially available blue-green algae dietary supplement in a dog. BMC Vet Res 2015; 11:136. [PMID: 26087767 PMCID: PMC4472392 DOI: 10.1186/s12917-015-0453-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Accepted: 06/09/2015] [Indexed: 11/15/2022] Open
Abstract
Background Dietary supplement use in both human and animals to augment overall health continues to increase and represents a potential health risk due to the lack of safety regulations imposed on the manufacturers. Because there are no requirements for demonstrating safety and efficacy prior to marketing, dietary supplements may contain potentially toxic contaminants such as hepatotoxic microcystins produced by several species of blue-green algae. Case presentation An 11-year-old female spayed 8.95 kg Pug dog was initially presented for poor appetite, lethargy polyuria, polydipsia, and an inability to get comfortable. Markedly increased liver enzyme activities were detected with no corresponding abnormalities evident on abdominal ultrasound. A few days later the liver enzyme activities were persistently increased and the dog was coagulopathic indicating substantial liver dysfunction. The dog was hospitalized for further care consisting of oral S-adenosylmethionine, silybin, vitamin K, and ursodeoxycholic acid, as well as intravenous ampicillin sodium/sulbactam sodium, dolasetron, N-acetylcysteine, metoclopramide, and intravenous fluids. Improvement of the hepatopathy and the dog’s clinical status was noted over the next three days. Assessment of the dog’s diet revealed the use of a commercially available blue-green algae dietary supplement for three-and-a-half weeks prior to hospitalization. The supplement was submitted for toxicology testing and revealed the presence of hepatotoxic microcystins (MCs), MC-LR and MC-LA. Use of the supplement was discontinued and follow-up evaluation over the next few weeks revealed a complete resolution of the hepatopathy. Conclusions To the authors’ knowledge, this is the first case report of microcystin intoxication in a dog after using a commercially available blue-green algae dietary supplement. Veterinarians should recognize the potential harm that these supplements may cause and know that with intervention, recovery is possible. In addition, more prudent oversight of dietary supplement use is recommended for our companion animals to prevent adverse events/intoxications.
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Affiliation(s)
| | - Caroline E Moore
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, CA, USA.
| | - Yanping Lin
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, CA, USA.
| | | | - Noemi Benitah
- Red Bank Veterinary Hospital, Tinton Falls, NJ, USA.
| | - Birgit Puschner
- California Animal Health and Food Safety Laboratory System, Davis, CA, USA. .,Department of Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, CA, USA.
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Li G, Yan W, Dang Y, Li J, Liu C, Wang J. The role of calcineurin signaling in microcystin-LR triggered neuronal toxicity. Sci Rep 2015; 5:11271. [PMID: 26059982 PMCID: PMC4462030 DOI: 10.1038/srep11271] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Accepted: 05/20/2015] [Indexed: 12/31/2022] Open
Abstract
Microcystin-LR (MCLR) is a commonly acting potent hepatotoxin and has been pointed out of potentially causing neurotoxicity, but the exact mechanisms of action still remain unclear. Using proteomic analysis, forty-five proteins were identified to be significantly altered in hippocampal neurons of rats treated with MCLR. Among them, Ca(2+)-activated phosphatase calcineurin (CaN) and the nuclear factor of activated T-cells isoform c3 (NFATc3) were up-regulated remarkably. Validation of the changes in CaN and NFATc3 expression by Western blotting demonstrated CaN cleavage and subsequent NFATc3 nuclear translocation were generated, suggesting that exposure to MCLR leads to activation of CaN, which in turn activates NFATc3. Activation of CaN signaling has been reported to result in apoptosis via dephosphorylation of the proapoptotic Bcl-2 family member Bad. In agreement with this, our results revealed that treatment of neurons with the CaN inhibitor FK506 blocked the reduction in Bad dephosphorylation and cytochrome c (cyt c) release triggered by MCLR. Consistent with these biochemical results, we observed a marked decrease in apoptotic and necrotic cell death after MCLR exposure in the presence of FK506, supporting the hypothesis that MCLR appeared to cause neuronal toxicity by activation of CaN and the CaN-mediated mitochondrial apoptotic pathway.
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Affiliation(s)
- Guangyu Li
- College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China
| | - Wei Yan
- Institute of Agricultural Quality Standards & Testing Technology, Hubei Academy of Agricultural Sciences, Wuhan 430064, China
| | - Yao Dang
- College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China
| | - Jing Li
- College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China
| | - Chunsheng Liu
- College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China
| | - Jianghua Wang
- College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China
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Piyathilaka MAPC, Pathmalal MM, Tennekoon KH, De Silva BGDNK, Samarakoon SR, Chanthirika S. Microcystin-LR-induced cytotoxicity and apoptosis in human embryonic kidney and human kidney adenocarcinoma cell lines. Microbiology (Reading) 2015; 161:819-28. [DOI: 10.1099/mic.0.000046] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2014] [Accepted: 01/26/2015] [Indexed: 01/08/2023] Open
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39
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Buratti FM, Testai E. Species- and congener-differences in microcystin-LR and -RR GSH conjugation in human, rat, and mouse hepatic cytosol. Toxicol Lett 2015; 232:133-40. [DOI: 10.1016/j.toxlet.2014.10.020] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2014] [Revised: 10/13/2014] [Accepted: 10/14/2014] [Indexed: 10/24/2022]
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40
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Chen L, Zhang X, Chen J, Zhang X, Fan H, Li S, Xie P. NF-κB plays a key role in microcystin-RR-induced HeLa cell proliferation and apoptosis. Toxicon 2014; 87:120-30. [PMID: 24932741 DOI: 10.1016/j.toxicon.2014.06.002] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2014] [Revised: 05/30/2014] [Accepted: 06/05/2014] [Indexed: 01/26/2023]
Abstract
Microcystins (MCs) are well-known cyanobacterial toxins produced in eutrophic waters and can act as potential carcinogens and have caused serious risk to human health. However, pleiotropic even paradoxical actions of cells exposure to MCs have been reported, and the mechanisms of MC-induced tumorigenesis and apoptosis are still unknown. In this study, we performed the first comprehensive in vitro investigation on carcinogenesis associated with nuclear factor kappa B (NF-κB) and its downstream genes in HeLa cells (Human cervix adenocarcinoma cell line from epithelial cells) exposure to MC-RR. HeLa cells were treated with 0, 20, 40, 60, and 80 µg/mL MC-RR for 4, 8, 12, and 24 h. HeLa cells presented dualistic responses to different doses of MCs. CCK8 assay showed that MC-RR exposure evidently enhanced cell viability of HeLa cells at lower MCs doses. Cell cycle and apoptosis analysis revealed that lower MCs doses promoted G1/S transition and cell proliferation while higher doses of MCs induced apoptosis, with a dose-dependent manner. Electrophoretic mobility shift assay (EMSA) revealed that MC-RR could increase/decrease NF-κB activity at lower/higher MC-RR doses, respectively. Furthermore, the expression of NF-κB downstream target genes including c-FLIP, cyclinD1, c-myc, and c-IAP2 showed the same variation trend as NF-κB activity both at mRNA and protein levels, which were induced by lower doses of MC-RR and suppressed by higher doses. Our data verified for the first time that NF-κB pathway may mediate MC-induced cell proliferation and apoptosis and provided a better understanding of the molecular mechanism for potential carcinogenicity of MC-RR.
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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
| | - Xin Zhang
- Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China; Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture, College of Fisheries, Huazhong Agricultural University, Wuhan, 430070, 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
- Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture, College of Fisheries, Huazhong Agricultural University, Wuhan, 430070, China
| | - Huihui Fan
- Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China; Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture, College of Fisheries, Huazhong Agricultural University, Wuhan, 430070, China
| | - Shangchun Li
- 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
| | - 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; Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture, College of Fisheries, Huazhong Agricultural University, Wuhan, 430070, China.
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41
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Microcystins alter chemotactic behavior in Caenorhabditis elegans by selectively targeting the AWA sensory neuron. Toxins (Basel) 2014; 6:1813-36. [PMID: 24918360 PMCID: PMC4073131 DOI: 10.3390/toxins6061813] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2014] [Revised: 05/17/2014] [Accepted: 05/28/2014] [Indexed: 11/16/2022] Open
Abstract
Harmful algal blooms expose humans and animals to microcystins (MCs) through contaminated drinking water. While hepatotoxicity following acute exposure to MCs is well documented, neurotoxicity after sub-lethal exposure is poorly understood. We developed a novel statistical approach using a generalized linear model and the quasibinomial family to analyze neurotoxic effects in adult Caenorhabditis elegans exposed to MC-LR or MC-LF for 24 h. Selective effects of toxin exposure on AWA versus AWC sensory neuron function were determined using a chemotaxis assay. With a non-monotonic response MCs altered AWA but not AWC function, and MC-LF was more potent than MC-LR. To probe a potential role for protein phosphatases (PPs) in MC neurotoxicity, we evaluated the chemotactic response in worms exposed to the PP1 inhibitor tautomycin or the PP2A inhibitor okadaic acid for 24 h. Okadaic acid impaired both AWA and AWC function, while tautomycin had no effect on function of either neuronal cell type at the concentrations tested. These findings suggest that MCs alter the AWA neuron at concentrations that do not cause AWC toxicity via mechanisms other than PP inhibition.
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42
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Survival, growth and toxicity of Microcystis aeruginosa PCC 7806 in experimental conditions mimicking some features of the human gastro-intestinal environment. Chem Biol Interact 2014; 215:54-61. [DOI: 10.1016/j.cbi.2014.03.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2013] [Revised: 01/21/2014] [Accepted: 03/15/2014] [Indexed: 01/06/2023]
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43
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Fan H, Cai Y, Xie P, Xiao W, Chen J, Ji W, Zhao S. Microcystin-LR stabilizes c-myc protein by inhibiting protein phosphatase 2A in HEK293 cells. Toxicology 2014; 319:69-74. [DOI: 10.1016/j.tox.2014.02.015] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2014] [Revised: 02/24/2014] [Accepted: 02/26/2014] [Indexed: 12/14/2022]
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44
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Zeng C, Sun H, Xie P, Wang J, Zhang G, Chen N, Yan W, Li G. The role of apoptosis in MCLR-induced developmental toxicity in zebrafish embryos. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2014; 149:25-32. [PMID: 24555956 DOI: 10.1016/j.aquatox.2014.01.021] [Citation(s) in RCA: 93] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2013] [Revised: 01/23/2014] [Accepted: 01/27/2014] [Indexed: 06/03/2023]
Abstract
We previously demonstrated that cyanobacteria-derived microcystin-leucine-arginine (MCLR) is able to induce developing toxicity, such as malformation, growth delay and also decreased heart rates in zebrafish embryos. However, the molecular mechanisms by which MCLR induces its toxicity during the development of zebrafish remain largely unknown. Here, we evaluate the role of apoptosis in MCLR-induced developmental toxicity. Zebrafish embryos were exposed to various concentrations of MCLR (0, 0.2, 0.5, 2, and 5.0 mg L(-1)) for 96 h, at which time reactive oxygen species (ROS) was significantly induced in the 2 and 5.0 mg L(-1) MCLR exposure groups. Acridine orange (AO) staining and terminal deoxynucleotide transferase-mediated deoxy-UTP nick end labelling (TUNEL) assay showed that MCLR exposure resulted in cell apoptosis. To test the apoptotic pathway, the expression pattern of several apoptotic-related genes was examined for the level of enzyme activity, gene and protein expression, respectively. The overall results demonstrate that MCLR induced ROS which consequently triggered apoptosis in the heart of developing zebrafish embryos. Our results also indicate that the p53-Bax-Bcl-2 pathway and the caspase-dependent apoptotic pathway play major roles in MCLR-induced apoptosis in the developing embryos.
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Affiliation(s)
- Cheng Zeng
- College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China
| | - Hong Sun
- Hubei Maternal and Child Health Hospital, Wuhan 430070, China
| | - Ping Xie
- Donghu Experimental Station of Lake Ecosystems, State Key Laboratory for Freshwater Ecology and Biotechnology of China, Institute of Hydrobiology, The Chinese Academy of Sciences, Wuhan 430072, China
| | - Jianghua Wang
- College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China
| | - Guirong Zhang
- College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China
| | - Nan Chen
- College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China
| | - Wei Yan
- Institute of Agricultural Quality Standards & Testing Technology, Hubei Academy of Agricultural Sciences, Wuhan 430064, China.
| | - Guangyu Li
- College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China; Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan 430070, China.
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45
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Wu J, Shao S, Zhou F, Wen S, Chen F, Han X. Reproductive toxicity on female mice induced by microcystin-LR. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2014; 37:1-6. [PMID: 24280256 DOI: 10.1016/j.etap.2013.10.012] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2013] [Revised: 10/12/2013] [Accepted: 10/19/2013] [Indexed: 06/02/2023]
Abstract
There are increasing concerns about health risk of human exposure to microcystin-LR (MC-LR) over the past few decades. Nevertheless, its female mammalian reproductive toxicity has not been addressed yet. In the present study, we firstly reported MC-LR could impact female reproductive function of mammals. After 28 days MC-LR exposure, relative ovary weight significantly reduced in 20 μg/kg MC-LR group and this reduction may be relative with pathomorphological changes of ovary. The result of histological evaluation of follicles showed that primordial follicles decreased roughly in half at high dose level compared with control. Since serum hormone assay indicated that MC-LR induced decrease of progesterone but not FSH or LH, disturbance of estrus cycle was seemed to result from direct impact of ovary rather than indirectly from hypothalamus or pituitary. As expected, MC-LR was detected in the ovaries of MC-LR exposure mice by immunoblot analysis.
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Affiliation(s)
- Jiang Wu
- Immunology and Reproductive Biology Laboratory, Medical School, Nanjing University, Nanjing 210093, China; Jiangsu Key Laboratory of Molecular Medicine, Nanjing University, Nanjing 210093, China; State Key Laboratory of Analytical Chemistry for Life Science, Nanjing University, 210093, China
| | - Sijia Shao
- Immunology and Reproductive Biology Laboratory, Medical School, Nanjing University, Nanjing 210093, China; Jiangsu Key Laboratory of Molecular Medicine, Nanjing University, Nanjing 210093, China; State Key Laboratory of Analytical Chemistry for Life Science, Nanjing University, 210093, China
| | - Fan Zhou
- Immunology and Reproductive Biology Laboratory, Medical School, Nanjing University, Nanjing 210093, China; Jiangsu Key Laboratory of Molecular Medicine, Nanjing University, Nanjing 210093, China; State Key Laboratory of Analytical Chemistry for Life Science, Nanjing University, 210093, China
| | - Siyuan Wen
- Immunology and Reproductive Biology Laboratory, Medical School, Nanjing University, Nanjing 210093, China; Jiangsu Key Laboratory of Molecular Medicine, Nanjing University, Nanjing 210093, China; State Key Laboratory of Analytical Chemistry for Life Science, Nanjing University, 210093, China
| | - Fu Chen
- Immunology and Reproductive Biology Laboratory, Medical School, Nanjing University, Nanjing 210093, China; Jiangsu Key Laboratory of Molecular Medicine, Nanjing University, Nanjing 210093, China; State Key Laboratory of Analytical Chemistry for Life Science, Nanjing University, 210093, China
| | - Xiaodong Han
- Immunology and Reproductive Biology Laboratory, Medical School, Nanjing University, Nanjing 210093, China; Jiangsu Key Laboratory of Molecular Medicine, Nanjing University, Nanjing 210093, China; State Key Laboratory of Analytical Chemistry for Life Science, Nanjing University, 210093, China.
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46
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Effects of the amino acid constituents of microcystin variants on cytotoxicity to primary cultured rat hepatocytes. Toxins (Basel) 2013; 6:168-79. [PMID: 24380975 PMCID: PMC3920255 DOI: 10.3390/toxins6010168] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2013] [Revised: 12/13/2013] [Accepted: 12/24/2013] [Indexed: 12/11/2022] Open
Abstract
Microcystins, which are cyclic heptapeptides produced by some cyanobacterial species from algal blooms, strongly inhibit serine/threonine protein phosphatase and are known as hepatotoxins. Microcystins have many structural variations, yet insufficient information is available on the differences in the cytotoxic potentials among the structural variants. In this study, the cytotoxicities of 16 microcystin variants at concentrations of 0.03–10 μg/mL to primary cultured rat hepatocytes were determined by measuring cellular ATP content, and subsequently determined by their 50% inhibitory concentration (IC50). Differences in the amino acid constituents were associated with differences in cytotoxic potential. [d-Asp3, Z-Dhb7] microcystin-LR exhibited the strongest cytotoxicity at IC50 of 0.053 μg/mL among the microcystin variants tested. Furthermore, [d-Asp3, Z-Dhb7] microcystin-HtyR was also highly cytotoxic. These results suggest that both d-Asp and Z-Dhb residues are important in determining the cytotoxic potential of microcystin variants.
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Roegner AF, Brena B, González-Sapienza G, Puschner B. Microcystins in potable surface waters: toxic effects and removal strategies. J Appl Toxicol 2013; 34:441-57. [PMID: 24038121 DOI: 10.1002/jat.2920] [Citation(s) in RCA: 80] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2013] [Revised: 07/16/2013] [Accepted: 07/17/2013] [Indexed: 02/01/2023]
Abstract
In freshwater, harmful cyanobacterial blooms threaten to increase with global climate change and eutrophication of surface waters. In addition to the burden and necessity of removal of algal material during water treatment processes, bloom-forming cyanobacteria can produce a class of remarkably stable toxins, microcystins, difficult to remove from drinking water sources. A number of animal intoxications over the past 20 years have served as sentinels for widespread risk presented by microcystins. Cyanobacterial blooms have the potential to threaten severely both public health and the regional economy of affected communities, particularly those with limited infrastructure or resources. Our main objectives were to assess whether existing water treatment infrastructure provides sufficient protection against microcystin exposure, identify available options feasible to implement in resource-limited communities in bloom scenarios and to identify strategies for improved solutions. Finally, interventions at the watershed level aimed at bloom prevention and risk reduction for entry into potable water sources were outlined. We evaluated primary studies, reviews and reports for treatment options for microcystins in surface waters, potable water sources and treatment plants. Because of the difficulty of removal of microcystins, prevention is ideal; once in the public water supply, the coarse removal of cyanobacterial cells combined with secondary carbon filtration of dissolved toxins currently provides the greatest potential for protection of public health. Options for point of use filtration must be optimized to provide affordable and adequate protection for affected communities.
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Affiliation(s)
- Amber F Roegner
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, CA, 95616, USA
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Faassen EJ, Lürling M. Occurrence of the microcystins MC-LW and MC-LF in Dutch surface waters and their contribution to total microcystin toxicity. Mar Drugs 2013; 11:2643-54. [PMID: 23880934 PMCID: PMC3736443 DOI: 10.3390/md11072643] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2013] [Revised: 07/08/2013] [Accepted: 07/12/2013] [Indexed: 12/04/2022] Open
Abstract
Microcystins (MCs) are the most frequently found cyanobacterial toxins in freshwater systems. Many MC variants have been identified and variants differ in their toxicity. Recent studies showed that the variants MC-LW and MC-LF might be more toxic than MC-LR, the variant that is most abundant and mostly used for risk assessments. As little is known about the presence of these two variants in The Netherlands, we determined their occurrence by analyzing 88 water samples and 10 scum samples for eight MC variants ((dm-7-)MC-RR, MC-YR, (dm-7-)MC-LR, MC-LY, MC-LW and MC-LF) by liquid chromatography with tandem mass spectrometry detection. All analyzed MC variants were detected, and MC-LW and/or MC-LF were present in 32% of the MC containing water samples. When MC-LW and MC-LF were present, they contributed to nearly 10% of the total MC concentrations, but due to their suspected high toxicity, their average contribution to the total MC toxicity was estimated to be at least 45%. Given the frequent occurrence and possible high toxicity of MC-LW and MC-LF, it seems better to base health risk assessments on the toxicity contributions of different MC variants than on MC-LR concentrations alone.
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Affiliation(s)
- Elisabeth J. Faassen
- Aquatic Ecology & Water Quality Management Group, Wageningen University, PO Box 47, Wageningen 6700 AA, The Netherlands; E-Mail:
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +31-317-483-898; Fax: +31-317-419-000
| | - Miquel Lürling
- Aquatic Ecology & Water Quality Management Group, Wageningen University, PO Box 47, Wageningen 6700 AA, The Netherlands; E-Mail:
- Department of Aquatic Ecology, Netherlands Institute of Ecology, Droevendaalsesteeg 10, Wageningen 6708 PB, The Netherlands
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49
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The conjugation of microcystin-RR by human recombinant GSTs and hepatic cytosol. Toxicol Lett 2013; 219:231-8. [DOI: 10.1016/j.toxlet.2013.03.015] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2013] [Revised: 03/15/2013] [Accepted: 03/18/2013] [Indexed: 01/18/2023]
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50
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Stipa G, Manganelli M, Lolli F. Cyanobacteria biomagnification and amyotrophic lateral sclerosis. Med Hypotheses 2013; 81:356-7. [PMID: 23673195 DOI: 10.1016/j.mehy.2013.04.039] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2013] [Revised: 04/15/2013] [Accepted: 04/23/2013] [Indexed: 10/26/2022]
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