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Saul N, Chakrabarti S, Stürzenbaum SR, Menzel R, Steinberg CEW. Neurotoxic action of microcystin-LR is reflected in the transcriptional stress response of Caenorhabditis elegans. Chem Biol Interact 2014; 223:51-7. [PMID: 25257166 DOI: 10.1016/j.cbi.2014.09.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2014] [Revised: 08/27/2014] [Accepted: 09/10/2014] [Indexed: 10/24/2022]
Abstract
Cyanobacterial blooms in aquatic environments are frequently characterized by elevated levels of microcystins, a potent hepatotoxin. Here we exposed the nematode Caenorhabditis elegans with environmentally realistic concentrations of MC-LR to explore its non-hepatic toxicity. Lifespan, reproduction and growth assays confirmed the toxic potential of 100μg/L MC-LR even in this liver-lacking invertebrate. Whole-genome microarray analysis revealed that a neuromodulating action was the dominant response in nematodes challenged with 100μg/L MC-LR. Indeed, most of the 201 differentially expressed genes were associated with neurobehavior, neurogenesis, and signaling associated pathways. In addition, a whole-genome miRNA-microarray highlighted that, in particular, members of the let-7 family were differentially regulated. These miRNAs are involved in the developmental timing of cell fates, including neurons, and are probably also part of the stress response system. To conclude, neurological modulation is the main transcriptional stress response in C. elegans exposed to MC-LR.
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Affiliation(s)
- Nadine Saul
- Department of Biology, Freshwater and Stress Ecology, Humboldt-Universität zu Berlin, Späthstr. 80/81, 12437 Berlin, Germany.
| | - Shumon Chakrabarti
- Department of Biology, Freshwater and Stress Ecology, Humboldt-Universität zu Berlin, Späthstr. 80/81, 12437 Berlin, Germany
| | - Stephen R Stürzenbaum
- School of Biomedical Sciences, Analytical and Environmental Sciences Division, King's College London, 150 Stamford Street, London SE1 9NH, UK
| | - Ralph Menzel
- Department of Biology, Freshwater and Stress Ecology, Humboldt-Universität zu Berlin, Späthstr. 80/81, 12437 Berlin, Germany
| | - Christian E W Steinberg
- Department of Biology, Freshwater and Stress Ecology, Humboldt-Universität zu Berlin, Späthstr. 80/81, 12437 Berlin, Germany
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52
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Li L, Liang XF, He S, Li G, Wen Z, Cai W, Shen D. Transcriptional responses of mu-, pi- and omega-class glutathione S-transferase genes in the hepatopancreas of Cipangopaludina cahayensis exposed to microcystin-LR. ACTA ACUST UNITED AC 2014. [DOI: 10.1007/s11434-014-0305-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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53
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Freitas EC, Pinheiro C, Rocha O, Loureiro S. Can mixtures of cyanotoxins represent a risk to the zooplankton? The case study of Daphnia magna Straus exposed to hepatotoxic and neurotoxic cyanobacterial extracts. HARMFUL ALGAE 2014; 31:143-152. [PMID: 28040103 DOI: 10.1016/j.hal.2013.11.004] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2013] [Revised: 11/12/2013] [Accepted: 11/13/2013] [Indexed: 05/28/2023]
Abstract
Worldwide, cyanobacterial blooms have been increasing in intensity and frequency, with toxic cyanobacteria sometimes dominant throughout the year in many freshwater bodies. Since the coexistence of more than one type of cyanotoxins in freshwater environments is a common phenomenon, studies on the joint effects of these toxins would be very useful. In this study, the single and combined effects of two cyanotoxins with different modes of action (hepatotoxic and neurotoxic) on the survival (lethal exposure) and feeding (sublethal exposure) of the cladoceran Daphnia magna were investigated. With the single exposures, it was observed that both the survival and feeding activity of the daphnids were impaired by the hepatotoxic and neurotoxic extracts at environmentally relevant concentrations. In the combined exposures, both survival and feeding rate endpoints showed a good fit to the independent action model. For the acute assay and 24h exposure period in the feeding inhibition test, there was no interaction between components of the hepatotoxic and neurotoxic extracts, although a slight tendency to a synergistic deviation could be seen in the feeding rates. On the other hand, for the 4h post-exposure period, a synergistic deviation was found in feeding rates at all mixture concentrations tested. Hence, the combined exposure of hepatotoxins and neurotoxins should also be taken into account in risk assessments of freshwater bodies, since the mixture of these toxins can result in more severe post-exposure effects on the feeding of daphnids than the sum of those expected for single exposures.
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Affiliation(s)
- Emanuela Cristina Freitas
- Department of Ecology and Evolutionary Biology, Federal University of São Carlos, Rodovia Washington Luis, km 235, CEP 13565-905 São Carlos, SP, Brazil.
| | - Carlos Pinheiro
- Department of Biology and Centre for Environmental and Marine Studies, University of Aveiro, 3810-193 Aveiro, Portugal.
| | - Odete Rocha
- Department of Ecology and Evolutionary Biology, Federal University of São Carlos, Rodovia Washington Luis, km 235, CEP 13565-905 São Carlos, SP, Brazil.
| | - Susana Loureiro
- Department of Biology and Centre for Environmental and Marine Studies, University of Aveiro, 3810-193 Aveiro, Portugal.
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54
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Sotton B, Guillard J, Anneville O, Maréchal M, Savichtcheva O, Domaizon I. Trophic transfer of microcystins through the lake pelagic food web: evidence for the role of zooplankton as a vector in fish contamination. THE SCIENCE OF THE TOTAL ENVIRONMENT 2014; 466-467:152-63. [PMID: 23906853 DOI: 10.1016/j.scitotenv.2013.07.020] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Revised: 05/30/2013] [Accepted: 07/04/2013] [Indexed: 05/08/2023]
Abstract
An in situ study was performed to investigate the role of zooplankton as a vector of microcystins (MCs) from Planktothrix rubescens filaments to fish during a metalimnic bloom of P. rubescens in Lake Hallwil (Switzerland). The concentrations of MCs in P. rubescens and various zooplanktonic taxa (filter-feeders and predators) were assessed in different water strata (epi-, meta- and hypolimnion) using replicated sampling over a 24-hour survey. The presence of P. rubescens in the gut content of various zooplanktonic taxa (Daphnia, Bosmina and Chaoborus) was verified by targeting the cyanobacterial nucleic acids (DNA). These results highlighted that cyanobacterial cells constitute a part of food resource for herbivorous zooplanktonic taxa during metalimnic bloom periods. Furthermore, presence of MCs in Chaoborus larvae highlighted the trophic transfer of MCs between herbivorous zooplankton and their invertebrate predators. Our results suggest that zooplanktonic herbivores by diel vertical migration (DVM) act as vectors of MCs by encapsulating grazed cyanobacteria. As a consequence, they largely contribute to the contamination of zooplanktonic predators, and in fine of zooplanktivorous whitefish. Indeed, we estimated the relative contribution of three preys of the whitefish (i.e. Daphnia, Bosmina and Chaoborus) to diet contamination. We showed that Chaoborus and Daphnia were the highest contributor as MC vectors in the whitefish diet (74.6 and 20.5% of MC-LR equivalent concentrations, respectively). The transfer of MCs across the different trophic compartments follows complex trophic pathways involving various trophic levels whose relative importance in fish contamination might vary at daily and seasonal scale.
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Affiliation(s)
- Benoît Sotton
- INRA, UMR CARRTEL, 75 av. de Corzent, F-74203 Thonon Les Bains, France.
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55
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Vareli K, Jaeger W, Touka A, Frillingos S, Briasoulis E, Sainis I. Hepatotoxic seafood poisoning (HSP) due to microcystins: a threat from the ocean? Mar Drugs 2013; 11:2751-68. [PMID: 23921721 PMCID: PMC3766863 DOI: 10.3390/md11082751] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2013] [Revised: 07/15/2013] [Accepted: 07/16/2013] [Indexed: 01/11/2023] Open
Abstract
Cyanobacterial blooms are a major and growing problem for freshwater ecosystems worldwide that increasingly concerns public health, with an average of 60% of blooms known to be toxic. The most studied cyanobacterial toxins belong to a family of cyclic heptapeptide hepatotoxins, called microcystins. The microcystins are stable hydrophilic cyclic heptapeptides with a potential to cause cell damage following cellular uptake via organic anion-transporting proteins (OATP). Their intracellular biologic effects presumably involve inhibition of catalytic subunits of protein phosphatases (PP1 and PP2A) and glutathione depletion. The microcystins produced by cyanobacteria pose a serious problem to human health, if they contaminate drinking water or food. These toxins are collectively responsible for human fatalities, as well as continued and widespread poisoning of wild and domestic animals. Although intoxications of aquatic organisms by microcystins have been widely documented for freshwater ecosystems, such poisonings in marine environments have only occasionally been reported. Moreover, these poisonings have been attributed to freshwater cyanobacterial species invading seas of lower salinity (e.g., the Baltic) or to the discharge of freshwater microcystins into the ocean. However, recent data suggest that microcystins are also being produced in the oceans by a number of cosmopolitan marine species, so that Hepatotoxic Seafood Poisoning (HSP) is increasingly recognized as a major health risk that follows consumption of contaminated seafood.
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Affiliation(s)
- Katerina Vareli
- Department of Biological Applications and Technologies, University of Ioannina, 45110 Ioannina, Greece; E-Mail:
- Interscience Molecular Oncology Laboratory, Human Cancer Biobank Center, University of Ioannina, 45110 Ioannina, Greece; E-Mails: (A.T.); (E.B.)
| | - Walter Jaeger
- Department of Clinical Pharmacy and Diagnostics, University of Vienna, A-1090 Vienna, Austria; E-Mail:
| | - Anastasia Touka
- Interscience Molecular Oncology Laboratory, Human Cancer Biobank Center, University of Ioannina, 45110 Ioannina, Greece; E-Mails: (A.T.); (E.B.)
| | - Stathis Frillingos
- Laboratory of Biological Chemistry, School of Medicine, University of Ioannina, 45110 Ioannina, Greece; E-Mail:
| | - Evangelos Briasoulis
- Interscience Molecular Oncology Laboratory, Human Cancer Biobank Center, University of Ioannina, 45110 Ioannina, Greece; E-Mails: (A.T.); (E.B.)
| | - Ioannis Sainis
- Interscience Molecular Oncology Laboratory, Human Cancer Biobank Center, University of Ioannina, 45110 Ioannina, Greece; E-Mails: (A.T.); (E.B.)
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +30-26-510-075-57; Fax: +30-26-510-070-64
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56
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He S, Liang XF, Sun J, Shen D. Induction of liver GST transcriptions by tert-butylhydroquinone reduced microcystin-LR accumulation in Nile tilapia (Oreochromis niloticus). ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2013; 90:128-135. [PMID: 23352130 DOI: 10.1016/j.ecoenv.2012.12.021] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2012] [Accepted: 12/21/2012] [Indexed: 06/01/2023]
Abstract
The cyanobacterial toxin, MC-LR, is predominantly presented during toxic cyanobacterial blooms and is consumed by phytoplanktivorous fish and zooplanktivorous fish directly. Detoxification of MC-LR in liver was believed to begin with conjugate formation with GSH, catalyzed by GSTs. MC-LR GSH conjugates display increased solubility and are subjected to accelerated biliary excretion. In this study, we showed that the mRNA transcriptions of GSTA, GPX and UCP2 were increased within 8h following MC-LR exposure in isolated hepatocytes of Nile tilapia, confirming the roles of phase II enzymes, especially GSTs, in MC-LR detoxification in tilapia. The widely used food-additive, synthetic antioxidant, tert-butylhydroquinone (tBHQ) has been shown to induce phase II enzymes including GSTs, via the antioxidant responsive elements (ARE) locate in the regulatory regions of these genes. Our results also showed that the transcription of various GSTs, including GSTA, GSTR2 and GSTT were significantly induced by tBHQ in Nile tilapia. In consistence, fish fed on tBHQ-containing diet (0.01 percent tBHQ) showed significantly reduced MC-LR accumulation in liver tissues 48 h after an oral administration of a single dose of 250 μg MC-LR/kg body weight (bwt). The findings in this research suggested that tBHQ could reduce MC-LR accumulations in liver, likely through the induction of phase II metabolizing enzymes such as GSTs. Subacute effects of tBHQ and its potential applications in fishery need to be further investigated.
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Affiliation(s)
- Shan He
- Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture, College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China
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57
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Analysis of MC-LR and MC-RR in tissue from freshwater fish (Tinca tinca) and crayfish (Procambarus clarkii) in tench ponds (Cáceres, Spain) by liquid chromatography-mass spectrometry (LC-MS). Food Chem Toxicol 2013; 57:170-8. [PMID: 23537600 DOI: 10.1016/j.fct.2013.03.025] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2013] [Revised: 03/06/2013] [Accepted: 03/15/2013] [Indexed: 11/21/2022]
Abstract
In the present study a new method has been developed and validated for detecting free microcystins (MCs) (MC-RR, MC-LR and MC-YR) by liquid chromatography-mass spectrometry (LC-MS) in the cyprinid Tinca tinca and in the crayfish Procambarus clarkii collected from three ponds in Extremadura (Spain) where the presence of the cyanobacteria species Microcystis aeruginosa and Anabaena spiroides has been confirmed. Once the method had been validated, free MCs were determined in fish (tench, T. tinca) and crayfish from different ponds in order to understand how they are bioaccumulated through the food web. MCs were not detected in any of the fish samples analyzed. It was confirmed that P. clarkii accumulated MCs in their tissues without losing their organoleptic characteristics, with MC-LR (2.3-18.1 μg MC-LR/g body weight) being the predominant MC variant detected in all the crayfish samples. MC-RR was measured in 50% of the samples analyzed, ranging between 1.4 and 7.8 μg MC-RR/g body weight and no MC-YR was detected. The results indicated that crayfish can accumulate free MCs in higher quantities than tench that live in ponds contaminated by toxic cyanobacteria species, and emphasized the need for regular monitoring if the health risks associated with their consumption are to be avoided.
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58
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A pharm-ecological perspective of terrestrial and aquatic plant-herbivore interactions. J Chem Ecol 2013; 39:465-80. [PMID: 23483346 DOI: 10.1007/s10886-013-0267-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2012] [Revised: 02/05/2013] [Accepted: 02/19/2013] [Indexed: 12/14/2022]
Abstract
We describe some recent themes in the nutritional and chemical ecology of herbivores and the importance of a broad pharmacological view of plant nutrients and chemical defenses that we integrate as "Pharm-ecology". The central role that dose, concentration, and response to plant components (nutrients and secondary metabolites) play in herbivore foraging behavior argues for broader application of approaches derived from pharmacology to both terrestrial and aquatic plant-herbivore systems. We describe how concepts of pharmacokinetics and pharmacodynamics are used to better understand the foraging phenotype of herbivores relative to nutrient and secondary metabolites in food. Implementing these concepts into the field remains a challenge, but new modeling approaches that emphasize tradeoffs and the properties of individual animals show promise. Throughout, we highlight similarities and differences between the historic and future applications of pharm-ecological concepts in understanding the ecology and evolution of terrestrial and aquatic interactions between herbivores and plants. We offer several pharm-ecology related questions and hypotheses that could strengthen our understanding of the nutritional and chemical factors that modulate foraging behavior of herbivores across terrestrial and aquatic systems.
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59
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D'ors A, Bartolomé MC, Sánchez-Fortún S. Toxic risk associated with sporadic occurrences of Microcystis aeruginosa blooms from tidal rivers in marine and estuarine ecosystems and its impact on Artemia franciscana nauplii populations. CHEMOSPHERE 2013; 90:2187-2192. [PMID: 23246722 DOI: 10.1016/j.chemosphere.2012.11.029] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2012] [Revised: 11/06/2012] [Accepted: 11/16/2012] [Indexed: 06/01/2023]
Abstract
Microcystis aeruginosa is a species of freshwater cyanobacteria which can form harmful algal blooms in freshwater water bodies worldwide. However, in spite its sporadic occurrences for short periods of time in estuarine waters, their influence on zooplankton populations present in these ecosystems has not been extensively studied. In this work, Artemia franciscana was used as test organism model, studying mortality against several strains of M. aeruginosa with different degrees of toxigenicity, measuring whole-live cells and homogenate extracts. Results were compared with microcystin-LR equivalent content, measured by immunoassay. The results show that there were no significant differences between both exposure models (whole cells and extracts), and there are significant differences respect to the toxigenicity of cyanobacterial blooms depending of the M. aerugionosa strain involved in the process. Analysis of microcystin-LR equivalent concentration test immediately below the lowest significant concentration in all M. aerugionosa strains was used to determine the potential risk associated with the cell densities during a bloom. Comparison among the selected M. aerugionsa strains show that these factors have influence in the results obtained, and thus, several differences have been evidenced depending of the microcystin-LR equivalent production and the strain type involved.
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Affiliation(s)
- A D'ors
- Dpto. Toxicología y Farmacología, Universidad Complutense de Madrid, Avenida Puerta de Hierro, s/n, 28040 Madrid, Spain
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60
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Gutiérrez-Praena D, Jos Á, Pichardo S, Moreno IM, Cameán AM. Presence and bioaccumulation of microcystins and cylindrospermopsin in food and the effectiveness of some cooking techniques at decreasing their concentrations: a review. Food Chem Toxicol 2012. [PMID: 23200893 DOI: 10.1016/j.fct.2012.10.062] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Microcystins (MCs) and cylindrospermopsin (CYN) are among the cyanotoxins which occur naturally, produced by different cyanobacteria species when they grow or proliferate under favorable environmental conditions. From a toxicological point of view, their relevance is due to the deleterious effects that they have been reported to induce in a wide range of organisms, including humans. Cyanotoxins intake from contaminated water and food is an important source of human exposure. Various edible aquatic organisms, plants, and food supplements based on algae, can bioaccumulate these toxins. A thorough review of the scientific data available on this topic is provided, the studies on MCs being much more numerous than those focused on CYN. The scientific literature suggests that these cyanotoxins can be accumulated at concentrations higher than their respective recommended tolerable daily intake (TDI). Finally, the influence of different cooking procedures on their levels in food has been considered. In this regard, again studies on the matter dealing with CYN have been not yet raised. MCs contents have been reported to be reduced in muscle of fish after boiling, or cooking in a microwave-oven, although the effect of other traditional cooking processes such as frying, roasting or grilling have not been demonstrated.
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Affiliation(s)
- Daniel Gutiérrez-Praena
- Nutrición y Bromatología, Toxicología y Medicina Legal Department, Faculty of Pharmacy, University of Sevilla, C/Profesor García González 2, 41012 Sevilla, Spain
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61
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Sotton B, Devaux A, Givaudan N, Guillard J, Domaizon I, Bony S, Anneville O. Short-term uptake of microcystin-LR by Coregonus lavaretus: GST activity and genotoxicity. ECOTOXICOLOGY (LONDON, ENGLAND) 2012; 21:1788-1796. [PMID: 22539116 DOI: 10.1007/s10646-012-0913-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 04/07/2012] [Indexed: 05/31/2023]
Abstract
In the present study, juvenile whitefish weighing 2 g were exposed by force-feeding to two ecologically relevant doses (0.05 and 0.5 μg per fish) of microcystin-LR (MC-LR). Then over 96 h the MC uptake in fish liver and muscle was measured, as the activity of the detoxification enzyme glutathione S-transferase (GST) in the liver, and the genotoxicity impact on red blood cells. Results show that (1) the MC-LR equivalent concentrations increased for both doses and in both organs of whitefish with approximately threefold lower concentrations for the low dose compared to the high dose in both organs and threefold lower concentrations in the muscle compared to the liver for each dose (2) the liver GST activity increased during the first 48 h of exposure with fivefold higher GST activity for the highest dose at 48 h compared to control and (3) MC-LR leads to deoxyribonucleic acid strand breaks that were detected by the comet assay and shown to be partially repaired. This work demonstrates that European whitefish could be impacted by cyanobacteria toxins due to rapid microcystin uptake, especially in the context of chronic contamination, which can occur during long bloom episodes.
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Affiliation(s)
- Benoît Sotton
- INRA, UMR CARRTEL, 75 av. de Corzent, 74203, Thonon Les Bains, France.
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62
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Acuña S, Baxa D, Teh S. Sublethal dietary effects of microcystin producing Microcystis on threadfin shad, Dorosoma petenense. Toxicon 2012; 60:1191-202. [PMID: 22925841 DOI: 10.1016/j.toxicon.2012.08.004] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2012] [Revised: 08/06/2012] [Accepted: 08/09/2012] [Indexed: 11/26/2022]
Abstract
The presence of the toxic cyanobacterium Microcystis in the upper San Francisco Estuary (SFE) since 1999 is a potential but unquantified threat to the health and survival of aquatic organisms such as fish and zooplankton. The microcystins (MCs) predominantly in the LR-form (MC-LR) produced by Microcystis is hepatotoxic and a potential threat to the fishery. Concurrently, in the SFE significant declines in pelagic fish, known as the Pelagic Organism Decline (POD), has been recognized by state and federal agencies since 2000. In 2005, the presence of the toxic algal bloom, Microcystis has been hypothesized as a link to the POD by the Interagency Ecology Program Management Team. This study aims to characterize the toxic effects of Microcystis in one of the POD species, threadfin shad (Dorosoma petenense) by exposure to diets containing Microcystis harvested from the SFE. The diets contained Microcystis with 4.4 (D5) and 10.0 (D10) μg g⁻¹ MC-LR that was fed to threadfin shad for 57 days. The treatments were compared to the control diet, 0 μg g⁻¹ MC-LR (D0). Results showed that ingested Microcystis was localized in the gut by in situ hybridization and MCs were localized in the tissues of the gut, kidney and liver. Condition factor (CF) and liver and gonadal lesions were sensitive to MC exposure. There was a significant inverse relationship between CF and MC-LR with exposed fish exhibiting severe cachexia. Liver lesions of sinusoidal congestion and glycogen depletion significantly increased with increasing MC-LR concentrations, indicating hemorrhaging in the liver and poor nutritional status, respectively. In females, there was a significant increase in severe ovarian necrosis with increasing MC-LR concentration, indicating loss of reproductive potential. The results indicate that MC-LR from Microcystis significantly impairs the health and reproductive potential of threadfin shad has a potential negative effect on populations in the SFE.
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Affiliation(s)
- Shawn Acuña
- Aquatic Health Program, Department of Anatomy, Physiology and Cell Biology, University of California, 1203 Haring Hall, 1 Shields Ave, Davis, CA 95616, USA.
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63
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Zhang J, Wang Z, Song Z, Xie Z, Li L, Song L. Bioaccumulation of microcystins in two freshwater gastropods from a cyanobacteria-bloom plateau lake, Lake Dianchi. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2012; 164:227-234. [PMID: 22366482 DOI: 10.1016/j.envpol.2012.01.021] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2011] [Revised: 01/08/2012] [Accepted: 01/15/2012] [Indexed: 05/31/2023]
Abstract
To investigate the bioaccumulation patterns of microcystins (MCs) in organs of two gastropods, samples were collected in Lake Dianchi monthly from May to October, 2008, when cyanobacteria typically bloom. The average MCs concentrations for Radix swinhoei (pulmonate) and Margarya melanioides (prosobranch) tended to be similar for the different organs: the highest values in the hepatopancreas (9.33 by 3.74 μg/g DW), followed by digestive tracts (1.66 by 3.03 μg/g DW), gonads (0.45 by 1.34 μg/g DW) and muscles (0.22 by 0.40 μg/g DW). Pulmonate had higher value than prosobranch because of the stronger bioaccumulation ability in hepatopancreas. The levels in organs of R. swinhoei were correlated with environmentally dissolved MCs, but influenced by intracellular MCs for M. melanioides. The estimated MCs concentrations in edible parts of M. melanioides were beyond the WHO's provisional tolerable daily intake (0.04 μg/kg), suggesting the risk of consumption of M. melanioides from the lake.
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Affiliation(s)
- Junqian Zhang
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei 430072, China
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64
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Papadimitriou T, Kagalou I, Stalikas C, Pilidis G, Leonardos ID. Assessment of microcystin distribution and biomagnification in tissues of aquatic food web compartments from a shallow lake and evaluation of potential risks to public health. ECOTOXICOLOGY (LONDON, ENGLAND) 2012; 21:1155-1166. [PMID: 22383140 DOI: 10.1007/s10646-012-0870-y] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 02/09/2012] [Indexed: 05/31/2023]
Abstract
The objectives of this study were: (1) to examine the distribution and bioaccumulation of microcystins in the main components of the food web (phytoplankton, zooplankton, crayfish, shrimp, mussel, snail, fish, frog) of Lake Pamvotis (NW Greece), (2) to investigate the possibility of microcystin biomagnification and (3) to evaluate the potential threat of the contaminated aquatic organisms to human health. Significant microcystin concentrations were detected in all the aquatic organisms during two different periods, with the higher concentrations observed in phytoplankton and the lower in fish species and frogs. This is the first study reporting microcystin accumulation in the body of the freshwater shrimp Atyaephyra desmsaresti, in the brain of the fish species common carp (Cyprinus carpio) and in the skin of the frog Rana epirotica. Although there was no evidence for microcystin biomagnification, the fact that microcystins were found in lake water and in the tissues of aquatic organisms, suggests that serious risks to animal and public health are possible to occur. In addition, it is likely to be unsafe to consume aquatic species harvested in Lake Pamvotis due to the high-concentrations of accumulated microcystins.
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Affiliation(s)
- Theodoti Papadimitriou
- Biological Applications and Technology Department, University of Ioannina, Ioannina, Greece
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65
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Lürling M, Faassen EJ. Controlling toxic cyanobacteria: effects of dredging and phosphorus-binding clay on cyanobacteria and microcystins. WATER RESEARCH 2012; 46:1447-1459. [PMID: 22137447 DOI: 10.1016/j.watres.2011.11.008] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2011] [Revised: 09/27/2011] [Accepted: 11/04/2011] [Indexed: 05/31/2023]
Abstract
Sediment dredging and Phoslock(®) addition were applied individually and in combination in an enclosure experiment in a Dutch hypertrophic urban pond. These measures were applied to control eutrophication and reduce the risk of exposure to cyanobacterial toxins. Over the 58 days course of the experiment, cyanobacteria (predominantly Microcystis aeruginosa) gradually decreased until they dropped below the level of detection in the combined treated enclosures, they were reduced in dredged enclosures, but remained flourishing in controls and Phoslock(®) treated enclosures. Cyanobacteria were, however, less abundant in the enclosures (medians chlorophyll-a 30-87 μg l(-1)) than in the pond (median chlorophyll-a 162 μg l(-1)), where also a thick surface scum covered one-third of the pond for many weeks. Soluble reactive phosphorus (SRP), total phosphorus and total nitrogen concentrations were significantly lower in the combined dredged and Phoslock(®) treated enclosures than in controls. Median SRP concentrations were 24 μg P l(-1) in the combined treatment, 58 μg P l(-1) in dredged enclosures, and 90 μg P l(-1) in controls and 95 μg P l(-1) in Phoslock(®) treated enclosures. Hence, the combined treatment was most effective in decreasing SRP and TP, and in lowering cyanobacterial biomass. Microcystin (MC) concentrations were analyzed by LC-MS/MS. MC concentrations and cyanobacterial biomass were positively correlated in all treatments. Mean MC concentrations in controls (71 μg l(-1)), Phoslock(®) treated enclosures (37 μg l(-1)) and dredged enclosures (25 μg l(-1)) exceeded the provisional guideline of 20 μg l(-1), whereas mean MC concentrations were 13 μg l(-1) in the combined treated enclosures. All samples contained the MC variants dmMC-RR, MC-RR, MC-YR, dmMC-LR and MC-LR; traces of MC-LY and nodularin were detected in few samples. The different treatments did not change the relative contribution of the variants to the MC pool; MC profiles in all treatments and the pond showed dominance of MC-RR followed by MC-LR. In the surface scum of the pond, total MC concentration was extremely high (64000 μg l(-1) or 1300 μg g(-1) DW), which poses a serious health hazard to children playing on the banks of the pond. Based on our results and pond characteristics, we propose combined sediment dredging and Phoslock(®) addition, fish removal and strong reduction of duck feeding by the neighborhood as most promising measures controlling cyanobacterial hazards in this pond.
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Affiliation(s)
- Miquel Lürling
- Aquatic Ecology & Water Quality Management Group, Department of Environmental Sciences, Wageningen University, P.O. Box 47, 6700 AA Wageningen, The Netherlands.
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Gonçalves-Soares D, Zanette J, Yunes JS, Yepiz-Plascencia GM, Bainy ACD. Expression and activity of glutathione S-transferases and catalase in the shrimp Litopenaeus vannamei inoculated with a toxic Microcystis aeruginosa strain. MARINE ENVIRONMENTAL RESEARCH 2012; 75:54-61. [PMID: 21889198 DOI: 10.1016/j.marenvres.2011.07.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2011] [Revised: 07/23/2011] [Accepted: 07/27/2011] [Indexed: 05/21/2023]
Abstract
Microcystin (MC) produced during cyanobacteria blooms is notably toxic to human and wildlife. Conjugation with reduced glutathione (GSH) by glutathione S-transferase (GST) and the antioxidant enzymes defenses (e.g. catalase, CAT) are important biochemical defense mechanisms against MCs toxicity. We investigated the enzymatic activity of CAT and GST and the gene expression levels of CAT and eight GST isoforms in the hepatopancreas of the globally farmed shrimp Litopenaeus vannamei 48-h after injection with a sub-lethal dose of 100 μg kg⁻¹ of a toxic Microcystis aeruginosa extract. MCs caused up-regulation for GSTΩ, μ and a MAPEG isoform, by 12-, 2.8- and 1.8-fold, respectively, and increases in the total GST enzyme activity and CAT enzyme activity. The study points to the importance of further characterization for the L. vannamei GST isoforms and GST/CAT post-translational regulation processes to better understand the key mechanisms involved in the shrimp's defense against MC exposure.
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Affiliation(s)
- Daniela Gonçalves-Soares
- Departamento de Bioquímica, Núcleo de Estudos em Patologia Aquícola, Universidade Federal de Santa Catarina, Servidão Caminho do Porto, s/n, Itacorubi, Florianópolis, SC 88034-257, Brazil
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Wang NX, Zhang XY, Wu J, Xiao L, Yin Y, Miao AJ, Ji R, Yang LY. Effects of microcystin-LR on the metal bioaccumulation and toxicity in Chlamydomonas reinhardtii. WATER RESEARCH 2012; 46:369-377. [PMID: 22078256 DOI: 10.1016/j.watres.2011.10.035] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2011] [Revised: 09/25/2011] [Accepted: 10/17/2011] [Indexed: 05/31/2023]
Abstract
Microcystin-LR (MC-LR) is one of the most notorious toxins liberated from cyanobacteria in eutrophicated freshwater ecosystems. Its effects on the bioaccumulation and toxicity of Cd(2+), CrO(4)(2-), Cu(2+), and Zn(2+) in a green alga Chlamydomonas reinhardtii were investigated in the present study. The metal bioaccumulation in the alga was unaffected by MC-LR. The surface-adsorbed and intracellular metal concentrations in the treatments with and without the addition of MC-LR could be well simulated by a single Freundlich isotherm for each metal with their accumulation ability following the order of Cu(2+) > Cd(2+) > Zn(2+) > CrO(4)(2-). The bioavailable metal concentrations measured by diffusion gradients in thin-films remained unchanged when MC-LR was applied. Accordingly, the growth of C. reinhardtii was similarly inhibited at the same metal concentration regardless of the addition of MC-LR. The metal toxicity could also be well delineated with the classic free ion activity and biotic ligand models. However, the intracellular metal concentration was found to have the best predictability suggesting its more direct relationship with metal toxicity. Metal exposure induced the accumulation of MC-LR in the alga, which was leveled off at high metal levels. The underlying uptake mechanisms need to be further examined.
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Affiliation(s)
- Ning-Xin Wang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, Jiangsu Province 210093, PR China
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Gélinas M, Juneau P, Gagné F. Early biochemical effects of Microcystis aeruginosa extracts on juvenile rainbow trout (Oncorhynchus mykiss). Comp Biochem Physiol B Biochem Mol Biol 2011; 161:261-7. [PMID: 22178707 DOI: 10.1016/j.cbpb.2011.12.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2011] [Revised: 12/02/2011] [Accepted: 12/05/2011] [Indexed: 11/29/2022]
Abstract
Microcystins (MC) are usually the predominant cyanotoxins associated with cyanobacterial blooms in natural surface waters. These toxins are well-known hepatotoxic agents that proceed by inhibiting protein phosphatase in aquatic biota; recent studies have also reported oxidative stress and disruption of ion regulation in aquatic organisms. In the present study, young trout (Oncorhynchus mykiss) were exposed to crude extracts of Microsystis aeruginosa for four days at 15 °C. The level of microcystins was calculated to confirm the presence of toxins in these crude extracts: 0, 0.75, 1.8 and 5 μg/L. Protein phosphatase measured in the liver increased by at least 3-fold and is significantly as a result of exposure to these sublethal concentrations of crude extract, his indicates an early defense response against protein phosphatase inhibition from cyanotoxins. This was corroborated by the decreased phosphate content in proteins found in the liver and brain. No increase in glutathione-S transferase (GST) activity was observed and lipid peroxidation was unaffected in both liver and brain tissue exposed to the cyanobacterial extracts. The data revealed that the proportion of the reduced (metal-binding) form of metallothionein (MT) decreased by two-fold relative to the control group (with a concomitant increase in the proportion of the oxidized form). The level of phosphate associated with MT increased by 1.5-fold at the highest concentration of crude extract. Acetylcholinesterase (AChE) activity in brain tissue was decreased after exposure to the highest concentration of crude extract, suggesting a slowdown in neural activity. However, no biotransformation processes or detoxification of GST was triggered. Our findings show early sign of biochemical effects of MC-LR in young trout.
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Affiliation(s)
- Malorie Gélinas
- Environment Canada, 105 McGill Street, Montréal, Quebec, Canada H2Y 2E7.
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Martins JC, Machado J, Martins A, Azevedo J, OlivaTeles L, Vasconcelos V. Dynamics of protein phosphatase gene expression in Corbicula fluminea exposed to microcystin-LR and to toxic Microcystis aeruginosa cells. Int J Mol Sci 2011; 12:9172-88. [PMID: 22272126 PMCID: PMC3257123 DOI: 10.3390/ijms12129172] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2011] [Revised: 11/21/2011] [Accepted: 11/30/2011] [Indexed: 12/31/2022] Open
Abstract
This study investigated the in vivo effects of microcystins on gene expression of several phosphoprotein phosphatases (PPP) in the freshwater clam Corbicula fluminea with two different exposure scenarios. Clams were exposed for 96 h to 5 μg L−1 of dissolved microcystin-LR and the relative changes of gene expression of three different types of PPP (PPP1, 2 and 4) were analyzed by quantitative real-time PCR. The results showed a significant induction of PPP2 gene expression in the visceral mass. In contrast, the cyanotoxin did not cause any significant changes on PPP1 and PPP4 gene expression. Based on these results, we studied alterations in transcriptional patterns in parallel with enzymatic activity of C. fluminea for PPP2, induced by a Microcystis aeruginosa toxic strain (1 × 105 cells cm−3) during 96 h. The relative changes of gene expression and enzyme activity in visceral mass were analyzed by quantitative real-time PCR and colorimetric assays respectively. The clams exhibited a significant reduction of PPP2 activity with a concomitant enhancement of gene expression. Considering all the results we can conclude that the exposure to an ecologically relevant concentration of pure or intracellular microcystins (-LR) promoted an in vivo effect on PPP2 gene expression in C. fluminea.
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Affiliation(s)
- José Carlos Martins
- CIIMAR/CIMAR, Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Rua dos Bragas 289, 4050-123 Porto, Portugal; E-Mails: (J.C.M.); (J.M.); (A.M.); (J.A.) (L.O.T.)
- Department of Biology, Faculty of Sciences, University of Porto, Rua do Campo Alegre, 4069-007 Porto, Portugal
| | - João Machado
- CIIMAR/CIMAR, Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Rua dos Bragas 289, 4050-123 Porto, Portugal; E-Mails: (J.C.M.); (J.M.); (A.M.); (J.A.) (L.O.T.)
| | - António Martins
- CIIMAR/CIMAR, Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Rua dos Bragas 289, 4050-123 Porto, Portugal; E-Mails: (J.C.M.); (J.M.); (A.M.); (J.A.) (L.O.T.)
| | - Joana Azevedo
- CIIMAR/CIMAR, Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Rua dos Bragas 289, 4050-123 Porto, Portugal; E-Mails: (J.C.M.); (J.M.); (A.M.); (J.A.) (L.O.T.)
| | - Luís OlivaTeles
- CIIMAR/CIMAR, Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Rua dos Bragas 289, 4050-123 Porto, Portugal; E-Mails: (J.C.M.); (J.M.); (A.M.); (J.A.) (L.O.T.)
- Department of Biology, Faculty of Sciences, University of Porto, Rua do Campo Alegre, 4069-007 Porto, Portugal
| | - Vitor Vasconcelos
- CIIMAR/CIMAR, Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Rua dos Bragas 289, 4050-123 Porto, Portugal; E-Mails: (J.C.M.); (J.M.); (A.M.); (J.A.) (L.O.T.)
- Department of Biology, Faculty of Sciences, University of Porto, Rua do Campo Alegre, 4069-007 Porto, Portugal
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +351-223401814; Fax: +351-223390608
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Guzmán-Guillén R, Prieto AI, Moreno I, Soria ME, Cameán AM. Effects of thermal treatments during cooking, microwave oven and boiling, on the unconjugated microcystin concentration in muscle of fish (Oreochromis niloticus). Food Chem Toxicol 2011; 49:2060-7. [PMID: 21621579 DOI: 10.1016/j.fct.2011.05.018] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2011] [Revised: 05/16/2011] [Accepted: 05/17/2011] [Indexed: 10/18/2022]
Abstract
Understanding the factors that contribute to the risk from fish consumption is a relevant public health concern due to potential adverse effects of cyanobacterial toxins. The aim of this work was to study the influence of two usual cooking practices, microwave oven and boiling, on the microcystin (MCs) concentration in fish muscle (Tilapia, Oreochromis niloticus) spiked with a stock solution (500 μL) containing a mixture of three toxins (MC-LR, MC-RR, and MC-YR) (1.5 μg/mL of each toxin). Two different variables were investigated: time of cooking in the microwaves treatment (1 or 5 min), and way of boiling, "boiled muscle" or "continuously heated muscle". All samples were then lyophilized and MCs were extracted and purified (Oasis HLB cartridge) and quantified by HPLC-MS. Furthermore, the waters in which the samples boiled were also analyzed after their purification. The results suggest a reduction on MC-LR (36%) and MC-YR (24.6%) in samples cooked in the microwave for 5 min. Major changes were found when the fish was cooked by the continuous boiling, with a decrease of 45.0% (MC-RR), 56.4% (MC-YR) and 59.3% (MC-LR). More studies are necessary to elucidate the mechanisms involved when aquatic food is submitted to usual cooking practices.
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Affiliation(s)
- Remedios Guzmán-Guillén
- Nutrición y Bromatología, Toxicología y Medicina Legal Department. Faculty of Pharmacy, University of Sevilla, C/ Profesor García González 2, 41012 Sevilla, Spain
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71
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Deblois CP, Giani A, Bird DF. Experimental model of microcystin accumulation in the liver of Oreochromis niloticus exposed subchronically to a toxic bloom of Microcystis sp. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2011; 103:63-70. [PMID: 21392496 DOI: 10.1016/j.aquatox.2011.02.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2010] [Revised: 02/10/2011] [Accepted: 02/12/2011] [Indexed: 05/30/2023]
Abstract
Although accumulation of the liver toxin microcystin in phytoplanktivorous fish has been demonstrated in captive fish and in natural ecosystems, the relation between microcystin in ingested algae and the pattern of buildup of microcystin in fish is poorly known. In this month-long study performed at a Brazilian fish farm, 45 mature Oreochromis niloticus were fed daily with fresh seston periodically dominated by toxic Microcystis sp. Microcystin was measured daily in the food and every 5 days in liver and muscle samples. Control fish received a diet of seston that was low in toxic cyanobacteria. Initially, in treatment ponds, microcystin available for fish increased from 6.5 to 66.9 ng microcystin fish(-1)day(-1), which was accompanied by an increase from 5.5 to 35.4 ng microcysting liver(-1). Microcystin in muscle was below our detection limit of 4 ng g tissue(-1) for the entire study. In the bloom phase, available microcystin reached its highest concentration (4450 ng MC fish(-1)day(-1)) then decreased to 910 ng microcystin fish(-1)day(-1) on day 31. During this period, microcystin reached its highest concentration of 81.6 ng MC g liver(-1) and stayed high until the end of the experiment. A model based on rapid uptake, saturation, and exponential loss was built with these experimental results, and verified with data from the literature. Our model showed that accumulation was up to 50% of ingestion at low doses, but at intermediate doses, the onset of elimination led to a decline of liver burden. Although the accumulation rate confirms the high contamination potential of microcystin, it was balanced by a high depuration rate and this efficient systemic elimination may explain the tolerance of these fish to toxic blooms in the wild.
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Affiliation(s)
- Charles P Deblois
- Dép. Sciences Biologiques, Université du Québec à Montréal (UQAM), C.P. 8888, Succ. Centre-Ville, Montréal, QC, Canada H3C 3P8
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72
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Malécot M, Marie A, Puiseux-Dao S, Edery M. iTRAQ-based proteomic study of the effects of microcystin-LR on medaka fish liver. Proteomics 2011; 11:2071-8. [DOI: 10.1002/pmic.201000512] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2010] [Revised: 01/20/2011] [Accepted: 02/17/2011] [Indexed: 11/07/2022]
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Dörr FA, Pinto E, Soares RM, Feliciano de Oliveira e Azevedo SM. Microcystins in South American aquatic ecosystems: Occurrence, toxicity and toxicological assays. Toxicon 2010; 56:1247-56. [DOI: 10.1016/j.toxicon.2010.03.018] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2009] [Revised: 03/15/2010] [Accepted: 03/22/2010] [Indexed: 12/23/2022]
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74
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Wang M, Wang D, Lin L, Hong H. Protein profiles in zebrafish (Danio rerio) brains exposed to chronic microcystin-LR. CHEMOSPHERE 2010; 81:716-724. [PMID: 20800265 DOI: 10.1016/j.chemosphere.2010.07.061] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2010] [Revised: 07/20/2010] [Accepted: 07/28/2010] [Indexed: 05/29/2023]
Abstract
Microcystin-LR (MCLR) is a commonly encountered blue-green algal hepatotoxin and a known inhibitor of cellular protein phosphatase (PP), however, little is known about its neurotoxicity. This study investigated the protein profiles of zebrafish (Danio rerio) brains chronically exposed to MCLR concentrations (2 or 20 μg L(-1)) using the proteomic approach. The results showed that MCLR strikingly enhanced toxin accumulation and the PP activity in zebrafish brains after 30 d exposure. Comparison of two-dimensional electrophoresis protein profiles of MCLR exposed and non-exposed zebrafish brains revealed that the abundance of 30 protein spots was remarkably altered in response to MCLR exposure. These proteins are involved in cytoskeleton assembly, macromolecule metabolism, oxidative stress, signal transduction, and other functions (e.g. transporting, protein degradation, apoptosis and translation), indicating that MCLR toxicity in the fish brain is complex and diverse. The chronic neurotoxicity of MCLR might initiate the PP pathway via an upregulation of PP2C in the zebrafish brain, in addition to the reactive oxygen species pathway. Additionally, the increase of vitellogenin abundance in MCLR exposed zebrafish brains suggested that MCLR might mimic the effects of endocrine disrupting chemicals. This study demonstrated that MCLR causes neurotoxicity in zebrafish at the proteomic level, which provides a new insight into MCLR toxicity in aquatic organisms and human beings.
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Affiliation(s)
- Minghua Wang
- State Key Laboratory of Marine Environmental Science/Environmental Science Research Center, Xiamen University, Xiamen 361005, People's Republic of China
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75
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Patterson AD, Gonzalez FJ, Idle JR. Xenobiotic metabolism: a view through the metabolometer. Chem Res Toxicol 2010; 23:851-60. [PMID: 20232918 DOI: 10.1021/tx100020p] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The combination of advanced ultraperformance liquid chromatography coupled with mass spectrometry, chemometrics, and genetically modified mice provide an attractive raft of technologies with which to examine the metabolism of xenobiotics. Here, a reexamination of the metabolism of the food mutagen PhIP (2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine), the suspect carcinogen areca alkaloids (arecoline, arecaidine, and arecoline 1-oxide), the hormone supplement melatonin, and the metabolism of the experimental cancer therapeutic agent aminoflavone is presented. In all cases, the metabolic maps of the xenobiotics were considerably enlarged, providing new insights into their toxicology. The inclusion of transgenic mice permitted unequivocal attribution of individual and often novel metabolic pathways to particular enzymes. Last, a future perspective for xenobiotic metabolomics is discussed and its impact on the metabolome is described. The studies reviewed here are not specific to the mouse and can be adapted to study xenobiotic metabolism in any animal species, including humans. The view through the metabolometer is unique and visualizes a metabolic space that contains both established and unknown metabolites of a xenobiotic, thereby enhancing knowledge of their modes of toxic action.
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Affiliation(s)
- Andrew D Patterson
- Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
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76
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Addressing the design ofin vitromodels for the investigation of microcystins: the essential role of transporter-mediated uptake. Cell Biol Int 2010; 34:907-9. [DOI: 10.1042/cbi20100244] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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77
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Lance E, Josso C, Dietrich D, Ernst B, Paty C, Senger F, Bormans M, Gérard C. Histopathology and microcystin distribution in Lymnaea stagnalis (Gastropoda) following toxic cyanobacterial or dissolved microcystin-LR exposure. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2010; 98:211-220. [PMID: 20227118 DOI: 10.1016/j.aquatox.2010.02.014] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2010] [Revised: 02/11/2010] [Accepted: 02/15/2010] [Indexed: 05/28/2023]
Abstract
The accumulation of hepatotoxic microcystins (MCs) in gastropods has been demonstrated to be higher following grazing of toxic cyanobacteria than from MCs dissolved in ambient water. Previous studies, however, did not adequately consider MCs covalently bound to protein phosphatases, which may represent a considerably part of the MC body burden. Thus, using an immunohistochemical method, we examined and compared the histopathology and organ distribution of covalently bound MCs in Lymnaea stagnalis following a 5-week exposure to (i) dmMC-LR, dmMC-RR, and MC-YR-producing Planktothrix agardhii (5 microg MC-LReqL(-1)) and (ii) dissolved MC-LR (33 and 100 microgL(-1)). A subsequent 3-week depuration investigated potential MC elimination and tissue regeneration. Following both exposures, bound MCs were primarily observed in the digestive gland and tract of L. stagnalis. Snails exposed to toxic cyanobacteria showed severe and widespread necrotic changes in the digestive gland co-occurring with a pronounced cytoplasmic presence of MCs in digestive cells and in the lumen of digestive lobules. Snails exposed to dissolved MC-LR showed moderate and negligible pathological changes of the digestive gland co-occurring with a restrained presence of MCs in the apical membrane of digestive cells and in the lumen of digestive lobules. These results confirm lower uptake of dissolved MC-LR and correspondingly lower cytotoxicity in the digestive gland of L. stagnalis. In contrast, after ingestion of MC-containing cyanobacterial filaments, the most likely longer residual time within the digestive gland and/or the MC variant involved (e.g., MC-YR) allowed for increased MC uptake, consequently a higher MC burden in situ and thus a more pronounced ensuing pathology. While no pathological changes were observed in kidney, foot and the genital gland, MCs were detected in spermatozoids and oocytes of all exposed snails, most likely involving a hemolymph transport from the digestive system to the genital gland. The latter results indicate the potential for adverse impact of MCs on gastropod health and reproduction as well as the possible transfer of MCs to higher trophic levels of the food web.
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Affiliation(s)
- Emilie Lance
- UMR CNRS 6553 ECOBIO, Université de Rennes 1, 263 Avenue du Général Leclerc, CS 74205, 35042 Rennes, France.
| | - Celine Josso
- UMR INRA Bio3P, Université de Rennes 1, 263 Avenue du Général Leclerc, CS 74205, 35042 Rennes Cedex, France
| | - Daniel Dietrich
- Human & Environmental Toxicology Group, University of Konstanz, D-78457 Konstanz, Germany
| | - Bernhard Ernst
- Human & Environmental Toxicology Group, University of Konstanz, D-78457 Konstanz, Germany
| | - Chrystelle Paty
- UMR INRA Bio3P, Université de Rennes 1, 263 Avenue du Général Leclerc, CS 74205, 35042 Rennes Cedex, France
| | - Fabrice Senger
- UMR CNRS 6026, Université de Rennes 1, 263 Avenue du Général Leclerc, CS 74205, 35042 Rennes Cedex, France
| | - Myriam Bormans
- UMR CNRS 6553 ECOBIO, Université de Rennes 1, 263 Avenue du Général Leclerc, CS 74205, 35042 Rennes, France
| | - Claudia Gérard
- UMR CNRS 6553 ECOBIO, Université de Rennes 1, 263 Avenue du Général Leclerc, CS 74205, 35042 Rennes, France
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Lance E, Neffling MR, Gérard C, Meriluoto J, Bormans M. Accumulation of free and covalently bound microcystins in tissues of Lymnaea stagnalis (Gastropoda) following toxic cyanobacteria or dissolved microcystin-LR exposure. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2010; 158:674-80. [PMID: 19906474 DOI: 10.1016/j.envpol.2009.10.025] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2009] [Revised: 09/28/2009] [Accepted: 10/15/2009] [Indexed: 05/21/2023]
Abstract
Accumulation of free microcystins (MCs) in freshwater gastropods has been demonstrated but accumulation of MCs covalently bound to tissues has never been considered so far. Here, we follow the accumulation of total (free and bound) MCs in Lymnaea stagnalis exposed to i) dissolved MC-LR (33 and 100 microg L(-1)) and ii) Planktothrix agardhii suspensions producing 5 and 33 microg MC-LR equivalents L(-1) over a 5-week period, and after a 3-week depuration period. Snails exposed to dissolved MC-LR accumulated up to 0.26 microg total MCs g(-1) dry weight (DW), with no detection of bound MCs. Snails exposed to MCs producing P. agardhii accumulated up to 69.9 microg total MCs g(-1) DW, of which from 17.7 to 66.7% were bound. After depuration, up to 15.3 microg g(-1) DW of bound MCs were detected in snails previously exposed to toxic cyanobacteria, representing a potential source of MCs transfer through the food web.
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Affiliation(s)
- Emilie Lance
- UMR CNRS Ecobio 6553, University of Rennes 1, Campus de Beaulieu, 265 Avenue du Général Leclerc, 35042 Rennes Cedex, France.
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Amado LL, Monserrat JM. Oxidative stress generation by microcystins in aquatic animals: why and how. ENVIRONMENT INTERNATIONAL 2010; 36:226-235. [PMID: 19962762 DOI: 10.1016/j.envint.2009.10.010] [Citation(s) in RCA: 203] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2009] [Revised: 09/09/2009] [Accepted: 10/27/2009] [Indexed: 05/28/2023]
Abstract
Microcystins (MICs) are potent toxins produced worldwide by cyanobacteria during bloom events. Phosphatases inhibition is a well recognized effect of this kind of toxins as well as oxidative stress. However, it is not fully understood why and how MICs exposure can lead to an excessive formation of reactive oxygen species (ROS) that culminate in oxidative damage. Some evidences suggest a close connection between cellular hyperphosphorylation state and oxidative stress generation induced by MICs exposure. It is shown, based on literature data, that MICs incorporation per se can be the first event that triggers glutathione depletion and the consequent increase in ROS concentration. Also, literature data suggest that hyperphosphorylated cellular environment induced by MICs exposure can modulate antioxidant enzymes, contributing to the generation of oxidative damage. This review summarizes information on MICs toxicity in aquatic animals, focusing on mechanistic aspects, and rise questions that in our opinion needs to be further investigated.
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Affiliation(s)
- L L Amado
- Curso de Pós-graduação em Ciências Fisiológicas - Fisiologia Animal Comparada, Cx. P. 474, CEP 96.201-900, Rio Grande, RS, Brazil
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