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Gorokhova E, El-Shehawy R. Antioxidant Responses in Copepods Are Driven Primarily by Food Intake, Not by Toxin-Producing Cyanobacteria in the Diet. Front Physiol 2022; 12:805646. [PMID: 35058807 PMCID: PMC8764287 DOI: 10.3389/fphys.2021.805646] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2021] [Accepted: 12/08/2021] [Indexed: 11/16/2022] Open
Abstract
The association between oxidative processes and physiological responses has received much attention in ecotoxicity assessment. In the Baltic Sea, bloom-forming cyanobacterium Nodularia spumigena is a significant producer of various bioactive compounds, and both positive and adverse effects on grazers feeding in cyanobacteria blooms are reported. To elucidate the effect mechanisms and species sensitivity to the cyanobacteria-dominating diet, we exposed two Baltic copepods, Acartia bifilosa and Eurytemora affinis, to a diet consisting of toxin-producing cyanobacteria N. spumigena and a high-quality food Rhodomonas salina at 0–300 μg C L−1; the control food was R. salina provided as a monodiet at the same food levels. The subcellular responses to food type and availability were assayed using a suite of biomarkers – antioxidant enzymes [superoxide dismutases (SOD), catalase (CAT), and glutathione S-transferases (GST)] and acetylcholinesterase (AChE). In parallel, we measured feeding activity using gut content (GC) assayed by real-time PCR analysis that quantified amounts of the prey DNA in copepod stomachs. As growth and reproduction endpoints, individual RNA content (a proxy for protein synthesis capacity), egg production rate (EPR), and egg viability (EV%) were used. In both toxic and nontoxic foods, copepod GC, RNA content, and EPR increased with food availability. Antioxidant enzyme activities increased with food availability regardless of the diet type. Moreover, CAT (both copepods), SOD, and GST (A. bifilosa) were upregulated in the copepods receiving cyanobacteria; the response was detectable when adjusted for the feeding and/or growth responses. By contrast, the diet effects were not significant when food concentration was used as a co-variable. A bimodal response in AChE was observed in A. bifilosa feeding on cyanobacteria, with up to 52% increase at the lower levels (5–25 μg C L−1) and 32% inhibition at the highest food concentrations. These findings contribute to the refinement of biomarker use for assessing environmental stress and mechanistic understanding of cyanobacteria effects in grazers. They also suggest that antioxidant and AChE responses to feeding activity and diet should be accounted for when using biomarker profiles in field-collected animals in the Baltic Sea and, perhaps other systems, where toxic cyanobacteria are common.
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Affiliation(s)
- Elena Gorokhova
- Department of Environmental Science, Stockholm University, Stockholm, Sweden
| | - Rehab El-Shehawy
- Department of Environmental Science, Stockholm University, Stockholm, Sweden
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2
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Gao J, Wang F, Jiang W, Miao J, Wang P, Zhou Z, Liu D. A full evaluation of chiral phenylpyrazole pesticide flufiprole and the metabolites to non-target organism in paddy field. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2020; 264:114808. [PMID: 32434115 DOI: 10.1016/j.envpol.2020.114808] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Revised: 05/09/2020] [Accepted: 05/12/2020] [Indexed: 05/27/2023]
Abstract
Pesticides applied to paddy fields may pose considerable danger to non-target aquatic organisms and further threaten human health. Flufiprole is a pesticide used in rice fields; considering the widespread existence of rice-fish-farming ecosystems, the acute toxicities of flufiprole enantiomers and its six metabolites (fipronil, flufiprole sulfide, flufiprole sulfone, detrifluoromethylsulfinyl flufiprole, desulfinyl flufiprole, and flufiprole amide) to four common aquatic organisms in rice fields including Misgurnus anguillicaudatus (pond loach), Carassius gibelio (Prussian carp), Pelophylax nigromaculatus (black-spotted frog), and Daphnia magna (water flea) were investigated. Genotoxicity, pathological changes and the effects on the antioxidant system of M. anguillicaudatus were also evaluated after exposure. The LC50 (EC50) values showed that fipronil and desulfinyl flufiprole were the most toxic compounds and were approximately about six times as toxic as flufiprole. No enantioselective toxicity was observed between the two enantiomers. The activity of antioxidant defense enzymes and the content of malondialdehyde (MDA) in the liver and gills of M. anguillicaudatus were significantly increased by the chemicals in most cases. In addition, fipronil and desulfinyl flufiprole were found to induce an increase in the micronucleus rate in M. anguillicaudatus. Histopathological analysis showed that the liver of M. anguillicaudatus was not significantly affected by flufiprole. Our study demonstrated a potential negative effect on flufiprole-treated aquatic organisms. As an alternative to fipronil, the environmental risk of flufiprole and its metabolites to non-target organisms in rice fields cannot be ignored.
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Affiliation(s)
- Jing Gao
- Beijing Advanced Innovation Centre for Food Nutrition and Human Health, Department of Applied Chemistry, China Agricultural University, No. 2 West Yuanmingyuan Road, Beijing, 100193, PR China
| | - Fang Wang
- Beijing Key Laboratory of Emerging Organic Contaminants Control, State Key Joint Laboratory of Environmental Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing, 100084, PR China
| | - Wenqi Jiang
- Beijing Advanced Innovation Centre for Food Nutrition and Human Health, Department of Applied Chemistry, China Agricultural University, No. 2 West Yuanmingyuan Road, Beijing, 100193, PR China
| | - Jingwen Miao
- Beijing Advanced Innovation Centre for Food Nutrition and Human Health, Department of Applied Chemistry, China Agricultural University, No. 2 West Yuanmingyuan Road, Beijing, 100193, PR China
| | - Peng Wang
- Beijing Advanced Innovation Centre for Food Nutrition and Human Health, Department of Applied Chemistry, China Agricultural University, No. 2 West Yuanmingyuan Road, Beijing, 100193, PR China
| | - Zhiqiang Zhou
- Beijing Advanced Innovation Centre for Food Nutrition and Human Health, Department of Applied Chemistry, China Agricultural University, No. 2 West Yuanmingyuan Road, Beijing, 100193, PR China
| | - Donghui Liu
- Beijing Advanced Innovation Centre for Food Nutrition and Human Health, Department of Applied Chemistry, China Agricultural University, No. 2 West Yuanmingyuan Road, Beijing, 100193, PR China.
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Huang IS, Zimba PV. Cyanobacterial bioactive metabolites-A review of their chemistry and biology. HARMFUL ALGAE 2019; 86:139-209. [PMID: 31358273 DOI: 10.1016/j.hal.2019.05.001] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Revised: 09/14/2018] [Accepted: 11/16/2018] [Indexed: 06/10/2023]
Abstract
Cyanobacterial blooms occur when algal densities exceed baseline population concentrations. Cyanobacteria can produce a large number of secondary metabolites. Odorous metabolites affect the smell and flavor of aquatic animals, whereas bioactive metabolites cause a range of lethal and sub-lethal effects in plants, invertebrates, and vertebrates, including humans. Herein, the bioactivity, chemistry, origin, and biosynthesis of these cyanobacterial secondary metabolites were reviewed. With recent revision of cyanobacterial taxonomy by Anagnostidis and Komárek as part of the Süβwasserflora von Mitteleuropa volumes 19(1-3), names of many cyanobacteria that produce bioactive compounds have changed, thereby confusing readers. The original and new nomenclature are included in this review to clarify the origins of cyanobacterial bioactive compounds. Due to structural similarity, the 157 known bioactive classes produced by cyanobacteria have been condensed to 55 classes. This review will provide a basis for more formal procedures to adopt a logical naming system. This review is needed for efficient management of water resources to understand, identify, and manage cyanobacterial harmful algal bloom impacts.
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Affiliation(s)
- I-Shuo Huang
- Center for Coastal Studies, Texas A&M University-Corpus Christi, 6300 Ocean Drive, Corpus Christi, TX 78412, USA.
| | - Paul V Zimba
- Center for Coastal Studies, Texas A&M University-Corpus Christi, 6300 Ocean Drive, Corpus Christi, TX 78412, USA
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4
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Huang IS, Zimba PV. Cyanobacterial bioactive metabolites-A review of their chemistry and biology. HARMFUL ALGAE 2019; 83:42-94. [PMID: 31097255 DOI: 10.1016/j.hal.2018.11.008] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Revised: 09/14/2018] [Accepted: 11/16/2018] [Indexed: 06/09/2023]
Abstract
Cyanobacterial blooms occur when algal densities exceed baseline population concentrations. Cyanobacteria can produce a large number of secondary metabolites. Odorous metabolites affect the smell and flavor of aquatic animals, whereas bioactive metabolites cause a range of lethal and sub-lethal effects in plants, invertebrates, and vertebrates, including humans. Herein, the bioactivity, chemistry, origin, and biosynthesis of these cyanobacterial secondary metabolites were reviewed. With recent revision of cyanobacterial taxonomy by Anagnostidis and Komárek as part of the Süβwasserflora von Mitteleuropa volumes 19(1-3), names of many cyanobacteria that produce bioactive compounds have changed, thereby confusing readers. The original and new nomenclature are included in this review to clarify the origins of cyanobacterial bioactive compounds. Due to structural similarity, the 157 known bioactive classes produced by cyanobacteria have been condensed to 55 classes. This review will provide a basis for more formal procedures to adopt a logical naming system. This review is needed for efficient management of water resources to understand, identify, and manage cyanobacterial harmful algal bloom impacts.
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Affiliation(s)
- I-Shuo Huang
- Center for Coastal Studies, Texas A&M University Corpus Christi, 6300 Ocean Drive, Corpus Christi, TX 78412, USA.
| | - Paul V Zimba
- Center for Coastal Studies, Texas A&M University Corpus Christi, 6300 Ocean Drive, Corpus Christi, TX 78412, USA
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Bownik A. Harmful algae: Effects of cyanobacterial cyclic peptides on aquatic invertebrates-a short review. Toxicon 2016; 124:S0041-0101(16)30319-1. [PMID: 27984061 DOI: 10.1016/j.toxicon.2016.10.017] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Revised: 10/24/2016] [Accepted: 10/27/2016] [Indexed: 12/22/2022]
Abstract
Cyanotoxins are secondary metabolites produced by cyanobacteria. Cyclic peptides, microcystins and nodularin commonly detected in water reservoirs of different parts of the world may induce various detrimental effects in a wide range of organisms from bacteria to humans. This paper presents the current state of knowledge on the effects of microcystins and nodularin on aquatic invertebrates: zooplankton, decapods and mollusks. Accumulation of microcystins and nodularin in these organisms and possible transfer of the cyanotoxins through the food web and possible threat to humans as consumers are also discussed.
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Affiliation(s)
- Adam Bownik
- Department of Biological Basis of Animal Production, University of Life Sciences, Akademicka 13 Str., 20-950 Lublin, Poland.
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Effect of dietary histamine supplementation on growth, digestive enzyme activities and morphology of intestine and hepatopancreas in the Chinese mitten crab Eriocheir sinensis. SPRINGERPLUS 2016; 5:552. [PMID: 27190751 PMCID: PMC4851676 DOI: 10.1186/s40064-016-2105-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Accepted: 04/05/2016] [Indexed: 12/04/2022]
Abstract
A 28-days feeding experiment was conducted to investigate the effect of histamine on digestive physiology of the Chinese mitten crab, Eriocheir sinensis. Four experimental diets were supplemented with histamine at 0, 1, 2, 4 g/kg. Histamine supplementation had no effect on growth. The activities of digestive enzyme decreased significantly at first (days 7 and 14) (p < 0.05) and then increased or finally slightly recovered in the hepatopancreas and intestinal tract on the 28th day. Tryptase and amylase activities were inhibited significantly in each histamine-treated group on day 7 as compared to the control (p < 0.05). On day 7, 14 and 28, tryptase mRNA relative expression in the histamine treatments correlated positively with the histamine concentration (p < 0.05). Histopathologic analyses showed serious alterations in hepatopancreas, moderate alterations in the hindgut and intestinal bulb, and no alterations in the midgut. In hepatopancreas, low levels (1 g/kg) of histamine caused an increase in the number of B-cells. High levels (4 g/kg) of histamine increased the number of R-cells, which were also highly vacuolized. In extreme cases, the basal lamina was detached from the tubule. In the intestinal bulb and hindgut, high levels of histamine (4 g/kg) decreased the density of reserve inclusion cells. Thus, this indicated that histamine had dose-dependent effect on the activity of digestive enzymes and the morphology of the intestine and hepatopancreas.
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Glutathione Transferases Responses Induced by Microcystin-LR in the Gills and Hepatopancreas of the Clam Venerupis philippinarum. Toxins (Basel) 2015; 7:2096-120. [PMID: 26067368 PMCID: PMC4488691 DOI: 10.3390/toxins7062096] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2015] [Accepted: 05/30/2015] [Indexed: 01/01/2023] Open
Abstract
A multi-method approach was employed to compare the responses of Glutatione Transferases (GSTs) in the gills and hepatopancreas of Venerupis philippinarum to microcystins (MCs) toxicity. In this way, using the cytosolic fraction, the enzymatic activity of GSTs, superoxide dismutase (SOD), serine/threonine protein phosphatases (PPP2) along with the gene expression levels of four GST isoforms (pi, mu, sigma1, sigma2) were investigated in both organs of the clams exposed for 24 h to 10, 50 and 100 μg L−1 of MC-LR. Cytosolic GSTs (cGSTs) from both organs of the high dose exposed clams were purified by glutathione-agarose affinity chromatography, characterized kinetically and the changes in the expression of cGSTs of the gills identified using a proteomic approach. MC-LR caused an increase in GST enzyme activity, involved in conjugation reactions, in both gills and hepatopancreas (100 μg L−1 exposure). SOD activity, an indicator of oxidative stress, showed significantly elevated levels in the hepatopancreas only (50 and 100 μg L−1 exposure). No significant changes were found in PPP2 activity, the main target of MCs, for both organs. Transcription responses revealed an up-regulation of sigma2 in the hepatopancreas at the high dose, but no significant changes were detected in the gills. Kinetic analysis evidenced differences between gills of exposed and non-exposed extracts. Using proteomics, qualitative and quantitative differences were found between the basal and inducible cGSTs. Overall, results suggest a distinct role of GST system in counteracting MCs toxicity between the gills and the hepatopancreas of V. philippinarum, revealing different roles between GST isoforms within and among both organs.
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8
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Clearwater SJ, Wood SA, Phillips NR, Parkyn SM, Van Ginkel R, Thompson KJ. Toxicity thresholds for juvenile freshwater mussels Echyridella menziesii and crayfish Paranephrops planifrons, after acute or chronic exposure to Microcystis sp. ENVIRONMENTAL TOXICOLOGY 2014; 29:487-502. [PMID: 22489020 DOI: 10.1002/tox.21774] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2011] [Revised: 02/05/2012] [Accepted: 02/07/2012] [Indexed: 05/31/2023]
Abstract
Survival of juvenile freshwater mussels (Echyridella menziesii (Gray, 1843) formerly known as Hyridella menziesi) and crayfish (Paranephrops planifrons, White, 1842) decreased after four days exposure to microcystin-containing cell-free extracts (MCFE) of Microcystis sp. at concentrations typical of severe cyanobacterial blooms. Crayfish survival was 100, 80, and 50% in microcystin concentrations of 1339, 2426, and 11146 μg L(-1) respectively, and shade- and shelter-seeking behavior was negatively affected when concentrations were ≥2426 μg L(-1) . Mussel survival decreased to 92% and reburial rates decreased to 16% after exposure for 96 h to MCFE containing microcystins at concentrations of 5300 μg L(-1) . Crayfish survival was 100% when fed freeze-dried Microcystis sp. incorporated into an artificial diet (6-100 μg microcystin kg(-1) ww) at dietary doses from 0.03 to 0.55 μg g(-1) body weight d(-1) for 27 days. Specific growth rate was significantly lower in crayfish fed ≥0.15 μg g(-1) body weight day(-1) compared with controls, but not compared with a diet incorporating nontoxic cyanobacteria. Microcystins accumulated preferentially in crayfish hepatopancreas and mussel digesta as MCFE or dietary concentrations increased. These laboratory data indicate that, assuming dissolved oxygen concentrations remain adequate, and no simultaneous exposure to live Microcystis sp. cells, cell-free microcystins will only be a significant stressor to juvenile crayfish and mussels in severe Microcystis sp. blooms. In contrast, crayfish were negatively affected by relatively low concentrations of microcystins in artificial diets compared with those measured locally in benthic cyanobacterial mats.
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Affiliation(s)
- S J Clearwater
- National Institute of Water and Atmospheric Research Ltd., PO Box 11115, Hamilton 3251, New Zealand
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Lyu K, Cao H, Chen R, Wang Q, Yang Z. Combined effects of hypoxia and ammonia to Daphnia similis estimated with life-history traits. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2013; 20:5379-5387. [PMID: 23417362 DOI: 10.1007/s11356-013-1555-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2012] [Accepted: 02/04/2013] [Indexed: 06/01/2023]
Abstract
The degradation of cyanobacterial blooms often causes hypoxia and elevated concentrations of ammonia, which can aggravate the adverse effects of blooms on aquatic organisms. However, it is not clear how one stressor would work in the presence of other coexistent stressors. We studied the toxic effects of elevated ammonia under hypoxia using a common yet important cladoceran species Daphnia similis isolated from heavily eutrophicated Lake Taihu. A 3 × 2 factorial experimental design was conducted with animals exposed to three un-ionized ammonia levels under two dissolved oxygen levels. Experiments lasted for 14 days and we recorded the life-history traits such as survival, molt, maturation, and fecundity. Results showed that hypoxia significantly decreased survival time and the number of molts of D. similis, whereas ammonia had no effect on them. Elevated ammonia significantly delayed development to maturity in tested animals and decreased their body sizes at maturity. Both ammonia and hypoxia were significantly detrimental to the number of broods, the number of offspring per female, and the number of total offspring per female, and significantly synergistic interactions were detected. Our data clearly demonstrate that elevated ammonia and hypoxia derived from cyanobacterial blooms synergistically affect the cladoceran D. similis.
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Affiliation(s)
- Kai Lyu
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing, 210023, China
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Liang J, Li T, Zhang YL, Guo ZL, Xu LH. Effect of microcystin-LR on protein phosphatase 2A and its function in human amniotic epithelial cells. J Zhejiang Univ Sci B 2012; 12:951-60. [PMID: 22135143 DOI: 10.1631/jzus.b1100121] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Due to their toxicity, the increased distribution of microcystins (MCs) has become an important worldwide problem. MCs have been recognized as inhibitors of protein phosphatase 2A (PP2A) through their binding to the PP2A catalytic subunit. However, the exact mechanism of MC toxicity has not been elucidated, especially concerning the cellular response and its autoregulation. To further dissect the role of PP2A in MC-induced toxicity, the present study was undertaken to determine the response of PP2A in human amniotic epithelial (FL) cells treated with microcystin-LR (MCLR), one of the MC congeners. The results show that a low-dose treatment of MCLR in FL cells for 6 h induced an increase in PP2A activity, and a high-dose treatment of MCLR for 24 h decreased the activity of PP2A, as expected. The increased mRNA and protein levels of the PP2A C subunit may explain the increased activity of PP2A. Furthermore, MCLR altered microtubule post-translational modifications through PP2A. These results further clarify the underlying mechanism how MCLR affects PP2A and may be helpful for elucidating the complex toxicity of MCLR.
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Affiliation(s)
- Jing Liang
- Department of Biochemistry and Genetics, School of Medicine, Zhejiang University, Hangzhou, China
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11
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Asselman J, Glaholt SP, Smith Z, Smagghe G, Janssen CR, Colbourne JK, Shaw JR, De Schamphelaere KAC. Functional characterization of four metallothionein genes in Daphnia pulex exposed to environmental stressors. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2012; 110-111:54-65. [PMID: 22266576 PMCID: PMC3967237 DOI: 10.1016/j.aquatox.2011.12.010] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2011] [Revised: 12/11/2011] [Accepted: 12/13/2011] [Indexed: 05/11/2023]
Abstract
We characterized the metallothionein genes (Mt1, Mt2, Mt3, and Mt4) in Daphnia pulex on both molecular and ecotoxicological level. We therefore conducted a bioinformatical analysis of the gene location and predicted protein sequence, and screened the upstream flanking region for regulatory elements. The number of these elements and their positions relative to the start codon varied strongly among the four genes and even among two gene duplicates (Mt1A and Mt1B), suggesting different roles of the four proteins in the organisms' response to stress. We subsequently conducted a chronic 16-day exposure of D. pulex to different environmental stressors (at sublethal levels causing approximately 50% reduction in reproduction). Based on prior knowledge, we exposed them to the metals Cd, Cu, and Ni, the moulting hormone hydroxyecdysone (20E), and the oxidative stressors cyanobacteria (Microcystis aeruginosa), and paraquat (Pq). We then compared mRNA expression levels of the four Mt genes under these stress conditions with control conditions in "The Chosen One" clone (TCO), for which the full genome was sequenced and annotated. All together, the mRNA expression results under the different stress regimes indicate that different Mt genes may play different and various roles in the response of D. pulex to stress and that some (but not all) of the differences among the four genes could be related to the pattern of regulatory elements in their upstream flanking region.
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Affiliation(s)
- J Asselman
- Laboratory of Environmental Toxicology and Aquatic Ecology, Ghent University, Belgium.
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12
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Li R, Zhou Y, Wang L, Ren G. Low-molecular-weight-chitosan ameliorates cadmium-induced toxicity in the freshwater crab, Sinopotamon yangtsekiense. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2011; 74:1164-1170. [PMID: 21392824 DOI: 10.1016/j.ecoenv.2011.02.018] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2011] [Revised: 02/15/2011] [Accepted: 02/20/2011] [Indexed: 05/30/2023]
Abstract
Cadmium (Cd) has been shown to induce oxidative stress. Low-molecular-weight-chitosan (LMWC) has been demonstrated to exhibit potent antioxidant effects. We investigated the regulation role in Cd²⁺-induced oxidative damage in the hepatopancreas of the freshwater crab Sinopotamon yangtsekiense and the protective effect of LMWC. The results showed that Cd²⁺ significantly increased the hepatopancreatic metallothionein (MT) mRNA levels and protein kinase C (PKC) activity while decreasing the activities of Na⁺,K⁺-ATPase and Ca²⁺-ATPase in crabs relative to the control group. Co-treatment with LMWC suppressed the levels of MT and PKC but raised the activities of Na⁺,K+-ATPase and Ca²⁺-ATPase in hepatopancreatic tissues compared with the crabs exposed to Cd²⁺ alone. We postulate that LMWC may exert its protective effect through regulating the expressions of MT, PKC, Na⁺,K⁺-ATPase and Ca²⁺-ATPase, thereby enhancing antioxidant defense. These observations suggest that LMWC may be beneficial because of its ability to alleviate the Cd²⁺-induced damages to the crabs.
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Affiliation(s)
- Ruijin Li
- School of Life Science, Shanxi University, Taiyuan 030006, Shanxi Province, PR China
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Gao QT, Tam NFY. Growth, photosynthesis and antioxidant responses of two microalgal species, Chlorella vulgaris and Selenastrum capricornutum, to nonylphenol stress. CHEMOSPHERE 2011; 82:346-354. [PMID: 21035163 DOI: 10.1016/j.chemosphere.2010.10.010] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2010] [Revised: 09/29/2010] [Accepted: 10/03/2010] [Indexed: 05/30/2023]
Abstract
The effect of nonylphenol (NP) on growth, photochemistry and biochemistry of two green microalgae, Chlorella vulgaris and Selenanstrum capricornutum, and their ability to degrade NP were compared. The 96 h EC50 of C. vulgaris and S. capricornutum were greater than 4.0 and 1.0 mg L(-1) NP, respectively, suggesting that the former species was more tolerant to NP. Both microalgae acclimated to NP stress through down-regulating their photosynthetic activities, including antenna size (chlorophyll a content), maximal photochemistry (Fv/Fm) and the light absorbed by PSII (ABS/CS0), but the dissipation of energy from reaction centres (DI0/RC) increased with the increase of NP concentrations. In C. vulgaris, the changes of these parameters were more significant than in S. capricornutum and recovered completely after a 96 h exposure. The antioxidant responses, such as GSH content, CAT and POD activities in C. vulgaris increased with the increase of NP concentrations after a 24h exposure, but these changes disappeared with exposure time and recovered to the control levels after 96 h. In S. capricornutum, although GSH content, CAT and POD activities also increased when exposed to low- to moderate-NP concentrations, these values were significantly reduced at a high concentration (4 mg L(-1)) even after a 96 h exposure, indicating its antioxidant responses were significantly delayed. It is clear that the more NP-tolerant species, C. vulgaris, acclimated better with a faster recovery of its photosynthetic activity from the NP-induced damage, and exhibited more efficient and rapid responses to NP-induced oxidative stress. C. vulgaris also had a higher NP degradation ability than S. capricornutum.
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Affiliation(s)
- Q T Gao
- Department of Biology and Chemistry, City University of Hong Kong, Hong Kong SAR, China
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Xing ML, Wang XF, Xu LH. Alteration of proteins expression in apoptotic FL cells induced by MCLR. ENVIRONMENTAL TOXICOLOGY 2008; 23:451-458. [PMID: 18214937 DOI: 10.1002/tox.20355] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Microcystins (MCs) are a family of monocyclic heptapeptide hepatotoxins produced by freshwater species of cyanobacteria. Microcystin-LR (MCLR) is the most frequently studied and most toxic in over 80 MC congeners. Great deals of studies have demonstrated that MCLR can induce apoptosis in a wide variety of cell types. Although much evidence indicates that mitochondria play a pivotal role in MCLR-induced apoptosis, the complicated apoptosis mechanisms induced by MCLR have not been completely characterized. It is possible that there are other apoptotic pathways existing in MCLR-induced apoptosis. The present study was undertaken to determine the expression of PP2A, CHOP, Bax, Bcl-2, and p53 proteins in MCLR-induced apoptosis in FL cells. The results showed that MCLR could induce apoptosis in FL cells and the process was accompanied with the upregulation of PP2A, Bax, and p53 proteins and the downregulation of Bcl-2 proteins. In addition, the CHOP protein was upregulated at most treatment groups and decreased at the highest concentration group. These results, especially the alteration of PP2A and CHOP proteins might provide new insights into MCLR-induced apoptosis.
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Affiliation(s)
- Ming-Luan Xing
- Department of Biochemistry and Genetics, School of Medicine, Zhejiang University, 388 Yu Hang Tang Road, Hangzhou 310058, China
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Cyanobacterial toxins: a qualitative meta-analysis of concentrations, dosage and effects in freshwater, estuarine and marine biota. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2008; 619:675-732. [PMID: 18461789 DOI: 10.1007/978-0-387-75865-7_32] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
This paper reviews the rapidly expanding literature on the ecological effects of cyanobacterial toxins. The study employs a qualitative meta-analysis from the literature examining results from a large number of independent studies and extracts general patterns from the literature or signals contradictions. The meta-analysis is set up by putting together two large tables--embodying a large and representative part of the literature (see Appendix A). The first table (Table A.1) reviews the presence (concentrations) of different cyanobacterial toxins in the tissues of various groups of aquatic biota after exposure via different routes, experimentally in the lab or via natural routes in the environment. The second table (Table A.2) reviews the dose dependent effect of toxins on biota. The great majority of studies deal with the presence and effects of microcystin, especially of the MC-LR congener. Although this may partly be justified--MC-LR is an abundant and highly toxic protein--our review also emphasizes what is known about (i) other MC congeners (a number of studies showed a preferred accumulation of the less toxic variant MC-RR in animal tissues), (ii) nodularin (data on a range of biota from studies on the Baltic Sea), (iii) neurotoxins like anatoxin-a(s), which are conspicuously often present at times when mass mortalities of birds occur, (iv) a few studies on the presence and effects of cylindrospermposin, as well as (v) the first examples of ecological effects of newly identified bioactive compounds, like microviridin-J. Data were reorganized to assess to what extent bioconcentration (uptake and concentration of toxins from the water) or biomagnification (uptake and concentration via the food) of cyanobacterial toxins occurs in ecosystems. There is little support for the occurrence of biomagnification, and this reduces the risk for biota at higher trophic levels. Rather than biomagnification biodilution seems to occur in the foodweb with toxins being subject to degradation and excretion at every level. Nevertheless toxins were present at all tropic levels, indicating that some vectorial transport must take place, and in sufficient quantities for effects to possibly occur. Feeding seemed to be the most important route for exposure of aquatic biota to cyanobacterial toxins. A fair number of studies focus on dissolved toxins, but in those studies purified toxin typically is used, and biota do not appear very sensitive to this form of exposure. More effects are found when crude cyanobacterial cell lysates are used, indicating that there may be synergistic effects between different bioactive compounds. Aquatic biota are by no means defenseless against toxic cyanobacteria. Several studies indicate that those species that are most frequently exposed to toxins in their natural environment are also the most tolerant. Protection includes behavioral mechanisms, detoxication of MC and NODLN by conjugation with glutathione, and fairly rapid depuration and excretion. A common theme in much of the ecological studies is that of modulating factors. Effects are seldom straightforward, but are dependent on factors like the (feeding) condition of the animals, environmental conditions and the history of exposure (acclimation and adaptation to toxic cyanobacteria). This makes it harder to generalize on what is known about ecological effects of cyanobacterial toxins. The paper concludes by summarizing the risks for birds, fish, macroinvertebrates and zooplankton. Although acute (lethal) effects are mentioned in the literature, mass mortalities of--especially--fish are more likely to be the result of multiple stress factors that co-occur during cyanobacterial blooms. Bivalves appear remarkably resistant, whilst the harmful effects of cyanobacteria on zooplankton vary widely and the specific contribution of toxins is hard to evaluate.
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Li L, Xie P, Li S, Qiu T, Guo L. Sequential ultrastructural and biochemical changes induced in vivo by the hepatotoxic microcystins in liver of the phytoplanktivorous silver carp Hypophthalmichthys molitrix. Comp Biochem Physiol C Toxicol Pharmacol 2007; 146:357-67. [PMID: 17574927 DOI: 10.1016/j.cbpc.2007.04.008] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2007] [Revised: 04/18/2007] [Accepted: 04/18/2007] [Indexed: 11/16/2022]
Abstract
Up to now, in vivo studies on the toxic effects of microcystins (MCs) on the ultrastructures of fish liver have been very limited. The phytoplanktivorous silver carp was injected i.p. with extracted hepatotoxic microcystins (mainly MC-RR and -LR) at a dose of 1000 microg MC-LReq. kg(-1) body weight, showing a time-dependent ultrastructural change in liver as well as significant increases in enzyme activity of plasma alanine aminotransferase (ALT), aspartate aminotransferase (AST) and lactate dehydrogenase (LDH). We observed for the first time the occurrence of a large amount of activated secondary lysosomes, which might be an adaptive mechanism to eliminate or lessen cell damage caused by MCs through lysosome activation. Quantitative and qualitative determinations of MCs in the liver were conducted by HPLC and LC-MS2, respectively. MCs concentration in the liver reached the maximum (114.20 microg g(-1) dry weight) after 3 h post-injection, and then rapidly dropped to 7.57 microg g(-1) dry weight at 48 h, indicating a depuration of 99% accumulated MC-LReq. On the other hand, a decrease trend in glutathione (GSH) concentration was observed in the liver of silver carp while the activity of glutathione S-transferase (GST) increased significantly after injection. The high tolerance of silver carp to MCs might be due to the high basic GSH level in their liver, and/or an increased GSH synthesis.
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Affiliation(s)
- Li Li
- Donghu Experimental Station of Lake Ecosystems, State Key Laboratory for Freshwater Ecology and Biotechnology of China, Institute of Hydrobiology, The Chinese Academy of Sciences, Donghu South Road 7, Wuhan 430072, P.R. China
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Rao PVL, Gupta N, Jayaraj R, Bhaskar ASB, Jatav PC. Age-dependent effects on biochemical variables and toxicity induced by cyclic peptide toxin microcystin-LR in mice. Comp Biochem Physiol C Toxicol Pharmacol 2005; 140:11-9. [PMID: 15792618 DOI: 10.1016/j.cca.2004.11.008] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/06/2004] [Revised: 11/18/2004] [Accepted: 11/19/2004] [Indexed: 11/22/2022]
Abstract
Microcystins are naturally occurring hepatotoxins produced by certain strains of Microcystis aeruginosa and microcystin-LR is the most toxic among the 60 microcystin variants isolated so far. These toxins have been implicated in both human and livestock mortality. In the present study we evaluated the age-dependent hepatotoxic effects of microcystin-LR (MC-LR) in mice after intraperitoneal and oral route of exposure. For acute toxicity studies by intraperitoneal route, 1 LD(50) dose of MC-LR (43.0 microg/kg) was administered to 6- to 36-week-old mice. Results showed that time to death in toxin treated animals decreased with age of mice. In comparison to control mice, treated animals of all age groups showed significant increases in liver body mass index and increases in serum enzymes (lactate dehydrogenase, alanine aminotransferase, aspartate aminotransferase, gamma-glutamyl transpeptidase, sorbitol dehydrogenase). For acute oral toxicity studies, 1 LD(50) of microcystin-LR containing extracts (3.5 g of MCE/kg) was administered to 6- and 36-week-old mice. The effects on biochemical variables were similar to intraperitoneal route of exposure. Significant age-dependent effects that were observed in microcystin treated animals by intraperitoneal and oral routes of exposure include: time to death, hepatic lipid peroxidation, glutathione depletion and DNA fragmentation. The age-dependent effects observed in some of the biochemical variables may be due to difference in the amount of microcystin-LR up take and also the age-dependent ability to detoxify the toxin in mice.
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Affiliation(s)
- P V Lakshmana Rao
- Division of Pharmacology and Toxicology, Defence Research and Development Establishment, Jhansi Road, Gwalior, India.
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