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Moreira-González AR, Domit C, Rosa KMS, Mafra LL. Occurrence of potentially toxic microalgae and diarrhetic shellfish toxins in the digestive tracts of green sea turtles (Chelonia mydas) from southern Brazil. HARMFUL ALGAE 2023; 128:102498. [PMID: 37714579 DOI: 10.1016/j.hal.2023.102498] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Revised: 08/22/2023] [Accepted: 09/01/2023] [Indexed: 09/17/2023]
Abstract
Algal toxins are involved in the mortality and/or illness of marine organisms via consumption of contaminated prey, or upon direct exposure to toxic cells. In this study, the presence of potentially toxic microalgal cells was investigated within the digestive tract contents of a threatened species of green turtle (Chelonia mydas). Additionally, lipophilic toxins were determined by LC-MS/MS in tissue samples (liver, stomach and/or intestine) of selected animals (n = 39 individuals) found dead-stranded in southern Brazil, from winter/2015 to autumn/2016. Thirteen potentially toxic species of microalgae (both benthic and planktonic), including seven dinoflagellates, six cyanobacteria and one diatom, were found in the digestive tract contents of green turtles. Among them, dinoflagellates belonging to the Dinophysis acuminata species complex were the most frequent (36%) and abundant (maximum average abundance of 566 cells g-1 in spring/2015). Moreover, 23% of the examined sea turtles exhibited detectable levels of the diarrhetic shellfish toxin okadaic acid (OA) in washed digestive tissues. Seven individuals accumulated OA in their intestines (max. 24.1 ng g-1) and two in the stomachs (max. 7.4 ng g-1). Toxin levels in the tissues were directly and significantly (r = 0.70, p < 0.025) associated with the cell abundance of OA-producing D. acuminata and Prorocentrum lima species complexes within the digestive contents of green turtles. Although OA concentrations were relatively low, possible chronic exposure might deteriorate general health conditions of exposed sea turtles, increasing the risk for diseases. Okadaic acid has been regarded as a tumor-promoting compound and an environmental co-factor in the incidence of fibropapillomatosis, a frequent disease in juvenile green turtles inhabiting this geographic region. Even though, only one green turtle containing OA in the digestive tissues (out of six examined) also presented fibropapillomatosis in this study. Notwithstanding, sea turtles are sentinels of ocean health. Monitoring the accumulation of algal toxins and their negative effects on these organisms contributes to conserving biodiversity and marine habitats.
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Affiliation(s)
- Angel R Moreira-González
- Centro de Estudos do Mar. Universidade Federal do Paraná. Cx. Postal 61. Pontal do Paraná. Paraná. 83255-976. Brazil; Centro de Estudios Ambientales de Cienfuegos (CEAC). Carretera a Castillo de Jagua. Km 1.5. AP. 5, Ciudad Nuclear 59350, Cienfuegos, Cuba
| | - Camila Domit
- Centro de Estudos do Mar. Universidade Federal do Paraná. Cx. Postal 61. Pontal do Paraná. Paraná. 83255-976. Brazil
| | - Kaianan M S Rosa
- Centro de Estudos do Mar. Universidade Federal do Paraná. Cx. Postal 61. Pontal do Paraná. Paraná. 83255-976. Brazil
| | - Luiz L Mafra
- Centro de Estudos do Mar. Universidade Federal do Paraná. Cx. Postal 61. Pontal do Paraná. Paraná. 83255-976. Brazil.
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Shishido TK, Delbaje E, Wahlsten M, Vuori I, Jokela J, Gugger M, Fiore MF, Fewer DP. A cylindrospermopin-producing cyanobacterium isolated from a microbial mat in the Baltic Sea. Toxicon 2023:107205. [PMID: 37406865 DOI: 10.1016/j.toxicon.2023.107205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Revised: 06/12/2023] [Accepted: 06/21/2023] [Indexed: 07/07/2023]
Abstract
Toxic benthic mats of cyanobacteria are associated with water quality problems and animal poisonings around the world. A strain of the filamentous cyanobacterial genus Kamptonema was isolated from a water bloom in the Baltic Sea four decades ago and later shown to produce cylindrospermopsins. However, the exact habitat of this strain remains unclear and cylindrospermopsins have not yet been reported from water blooms in the Baltic Sea. Here, we report the isolation of Kamptonema sp. UHCC 0994 from a benthic microbial mat collected in shallow water on the coast of Helsinki. We obtained draft genome sequences for the Kamptonema spp. PCC 7926 and UHCC 0994 strains that were isolated from the Baltic Sea. These genomes were 90-96% similar to previously studied Kamptonema sp. PCC 6506 and Kamptonema formosum PCC 6407, which were isolated from benthic and North American freshwater environments, respectively. The genomes of all four Kamptonema strains encode complete cylindrospermopsin biosynthetic gene clusters. We detected the production of cylindrospermopsin and 7-epi-cylindrospermopsin in the four Kamptonema strains using high-resolution liquid chromatography mass spectrometry. The four strains encode genes for producing gas vesicles distributed in two to three different regions of their genomes. Kamptonema spp. UHCC 0994 and PCC 7926 have both retained the ability to regulate their buoyancy when grown in liquid culture. Together this suggests that these toxic cyanobacteria may exhibit a tychoplanktic lifestyle in the Baltic Sea. This study suggests that microbial mats containing cyanobacteria could be a source of environmental toxins in the Baltic Sea.
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Affiliation(s)
- Tania Keiko Shishido
- Department of Microbiology, Faculty of Agriculture and Forestry, University of Helsinki, Viikinkaari 9, FI-00014, Helsinki, Finland
| | - Endrews Delbaje
- Department of Microbiology, Faculty of Agriculture and Forestry, University of Helsinki, Viikinkaari 9, FI-00014, Helsinki, Finland; Center for Nuclear Energy in Agriculture, University of São Paulo, Avenida Centenário 303, Piracicaba, 13400-970, São Paulo, Brazil
| | - Matti Wahlsten
- Department of Microbiology, Faculty of Agriculture and Forestry, University of Helsinki, Viikinkaari 9, FI-00014, Helsinki, Finland
| | - Inkeri Vuori
- Department of Microbiology, Faculty of Agriculture and Forestry, University of Helsinki, Viikinkaari 9, FI-00014, Helsinki, Finland
| | - Jouni Jokela
- Department of Microbiology, Faculty of Agriculture and Forestry, University of Helsinki, Viikinkaari 9, FI-00014, Helsinki, Finland
| | - Muriel Gugger
- Institut Pasteur, Université Paris Cité, Collection of Cyanobacteria, Paris, F-75015, France
| | - Marli F Fiore
- Center for Nuclear Energy in Agriculture, University of São Paulo, Avenida Centenário 303, Piracicaba, 13400-970, São Paulo, Brazil
| | - David P Fewer
- Department of Microbiology, Faculty of Agriculture and Forestry, University of Helsinki, Viikinkaari 9, FI-00014, Helsinki, Finland.
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Gkelis S, Panou M, Konstantinou D, Apostolidis P, Kasampali A, Papadimitriou S, Kati D, Di Lorenzo GM, Ioakeim S, Zervou SK, Christophoridis C, Triantis TM, Kaloudis T, Hiskia A, Arsenakis M. Diversity, Cyanotoxin Production, and Bioactivities of Cyanobacteria Isolated from Freshwaters of Greece. Toxins (Basel) 2019; 11:toxins11080436. [PMID: 31349572 PMCID: PMC6723990 DOI: 10.3390/toxins11080436] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 07/12/2019] [Accepted: 07/23/2019] [Indexed: 12/28/2022] Open
Abstract
Cyanobacteria are a diverse group of photosynthetic Gram-negative bacteria that produce an array of secondary compounds with selective bioactivity against a broad spectrum of organisms and cell lines. In this study, 29 strains isolated from freshwaters in Greece were classified using a polyphasic approach and assigned to Chroococcales, Synechococcales, and Nostocales, representing 11 genera and 17 taxa. There were good agreements between 16S ribosomal RNA (rRNA)-cpcBA-internal genetic spacer (IGS) characterization and morphological features, except for the Jaaginema-Limnothrix group which appears intermixed and needs further elucidation. Methanol extracts of the strains were analyzed for cyanotoxin production and tested against pathogenic bacteria species and several cancer cell lines. We report for the first time a Nostoc oryzae strain isolated from rice fields capable of producing microcystins (MCs) and a Chlorogloeopsis fritschii strain isolated from the plankton of a lake, suggesting that this species may also occur in freshwater temperate habitats. Strains with very high or identical 16S rRNA gene sequences displayed different antibacterial and cytotoxic activities. Extracts from Synechococcus cf. nidulans showed the most potent antibacterial activity against Staphylococcus aureus, whereas Jaaginema sp. strains exhibited potent cytotoxic activities against human colorectal adenocarcinoma and hepatocellular carcinoma cells. Jaaginema Thessaloniki Aristotle University Microalgae and Cyanobacteria (TAU-MAC) 0110 and 0210 strains caused pronounced changes in the actin network and triggered the formation of numerous lipid droplets in hepatocellular carcinoma and green monkey kidney cells, suggesting oxidative stress and/or mitochondrial damage leading to apoptosis.
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Affiliation(s)
- Spyros Gkelis
- Department of Botany, School of Biology, Aristotle University of Thessaloniki, GR-541 24 Thessaloniki, Greece.
| | - Manthos Panou
- Department of Botany, School of Biology, Aristotle University of Thessaloniki, GR-541 24 Thessaloniki, Greece
| | - Despoina Konstantinou
- Department of Botany, School of Biology, Aristotle University of Thessaloniki, GR-541 24 Thessaloniki, Greece
| | - Panagiotis Apostolidis
- Department of Botany, School of Biology, Aristotle University of Thessaloniki, GR-541 24 Thessaloniki, Greece
- Department of Genetics, Development and Molecular Biology, School of Biology, Aristotle University of Thessaloniki, GR-541 24 Thessaloniki, Greece
| | - Antonia Kasampali
- Department of Botany, School of Biology, Aristotle University of Thessaloniki, GR-541 24 Thessaloniki, Greece
- Department of Genetics, Development and Molecular Biology, School of Biology, Aristotle University of Thessaloniki, GR-541 24 Thessaloniki, Greece
| | - Sofia Papadimitriou
- Department of Botany, School of Biology, Aristotle University of Thessaloniki, GR-541 24 Thessaloniki, Greece
| | - Dominiki Kati
- Department of Botany, School of Biology, Aristotle University of Thessaloniki, GR-541 24 Thessaloniki, Greece
| | - Giorgia Maria Di Lorenzo
- Department of Botany, School of Biology, Aristotle University of Thessaloniki, GR-541 24 Thessaloniki, Greece
- Department of Genetics, Development and Molecular Biology, School of Biology, Aristotle University of Thessaloniki, GR-541 24 Thessaloniki, Greece
| | - Stamatia Ioakeim
- Department of Botany, School of Biology, Aristotle University of Thessaloniki, GR-541 24 Thessaloniki, Greece
- Department of Genetics, Development and Molecular Biology, School of Biology, Aristotle University of Thessaloniki, GR-541 24 Thessaloniki, Greece
| | - Sevasti-Kiriaki Zervou
- Laboratory of Photo-Catalytic Processes and Environmental Chemistry, Institute of Nanoscience & Nanotechnology, National Center for Scientific Research "Demokritos", Patriarchou Grigoriou & Neapoleos, Agia Paraskevi, 15341 Athens, Greece
| | - Christophoros Christophoridis
- Laboratory of Photo-Catalytic Processes and Environmental Chemistry, Institute of Nanoscience & Nanotechnology, National Center for Scientific Research "Demokritos", Patriarchou Grigoriou & Neapoleos, Agia Paraskevi, 15341 Athens, Greece
| | - Theodoros M Triantis
- Laboratory of Photo-Catalytic Processes and Environmental Chemistry, Institute of Nanoscience & Nanotechnology, National Center for Scientific Research "Demokritos", Patriarchou Grigoriou & Neapoleos, Agia Paraskevi, 15341 Athens, Greece
| | - Triantafyllos Kaloudis
- Laboratory of Photo-Catalytic Processes and Environmental Chemistry, Institute of Nanoscience & Nanotechnology, National Center for Scientific Research "Demokritos", Patriarchou Grigoriou & Neapoleos, Agia Paraskevi, 15341 Athens, Greece
| | - Anastasia Hiskia
- Laboratory of Photo-Catalytic Processes and Environmental Chemistry, Institute of Nanoscience & Nanotechnology, National Center for Scientific Research "Demokritos", Patriarchou Grigoriou & Neapoleos, Agia Paraskevi, 15341 Athens, Greece
| | - Minas Arsenakis
- Department of Genetics, Development and Molecular Biology, School of Biology, Aristotle University of Thessaloniki, GR-541 24 Thessaloniki, Greece
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Tripathi VC, Satish S, Horam S, Raj S, lal A, Arockiaraj J, Pasupuleti M, Dikshit DK. Natural products from polar organisms: Structural diversity, bioactivities and potential pharmaceutical applications. POLAR SCIENCE 2018; 18:147-166. [DOI: 10.1016/j.polar.2018.04.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/16/2023]
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Shunmugam S, Jokela J, Wahlsten M, Battchikova N, Vass I, Karonen M, Sinkkonen J, Permi P, Sivonen K, Aro EM, Allahverdiyeva Y. Secondary metabolite from Nostoc XPORK14A inhibits photosynthesis and growth of Synechocystis PCC 6803. PLANT, CELL & ENVIRONMENT 2014; 37:1371-1381. [PMID: 24895757 DOI: 10.1111/pce.12243] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Screening of 55 different cyanobacterial strains revealed that an extract from Nostoc XPORK14A drastically modifies the amplitude and kinetics of chlorophyll a fluorescence induction of Synechocystis PCC6803 cells.After 2 d exposure to the Nostoc XPORK14A extract, Synechocystis PCC 6803 cells displayed reduced net photosynthetic activity and significantly modified electron transport properties of photosystem II under both light and dark conditions. However, the maximum oxidizable amount of P700 was not strongly affected. The extract also induced strong oxidative stress in Synechocystis PCC 6803 cells in both light and darkness. We identified the secondary metabolite of Nostoc XPORK14A causing these pronounced effects on Synechocystis cells. Mass spectrometry and nuclear magnetic resonance analyses revealed that this compound, designated as M22, has a non-peptide structure. We propose that M22 possesses a dualaction mechanism: firstly, by photogeneration of reactive oxygen species in the presence of light, which in turn affects the photosynthetic machinery of Synechocystis PCC 6803; and secondly, by altering the in vivo redox status of cells, possibly through inhibition of protein kinases.
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Cyanobacteria from terrestrial and marine sources contain apoptogens able to overcome chemoresistance in acute myeloid leukemia cells. Mar Drugs 2014; 12:2036-53. [PMID: 24705501 PMCID: PMC4012442 DOI: 10.3390/md12042036] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2014] [Revised: 03/13/2014] [Accepted: 03/18/2014] [Indexed: 01/12/2023] Open
Abstract
In this study, we investigated forty cyanobacterial isolates from biofilms, gastropods, brackish water and symbiotic lichen habitats. Their aqueous and organic extracts were used to screen for apoptosis-inducing activity against acute myeloid leukemia cells. A total of 28 extracts showed cytotoxicity against rat acute myeloid leukemia (IPC-81) cells. The design of the screen made it possible to eliminate known toxins, such as microcystins and nodularin, or known metabolites with anti-leukemic activity, such as adenosine and its analogs. A cytotoxicity test on human embryonic kidney (HEK293T) fibroblasts indicated that 21 of the 28 extracts containing anti-acute myeloid leukemia (AML) activity showed selectivity in favor of leukemia cells. Extracts L26-O and L30-O were able to partly overcome the chemotherapy resistance induced by the oncogenic protein Bcl-2, whereas extract L1-O overcame protection from the deletion of the tumor suppressor protein p53. In conclusion, cyanobacteria are a prolific resource for anti-leukemia compounds that have potential for pharmaceutical applications. Based on the variety of cellular responses, we also conclude that the different anti-leukemic compounds in the cyanobacterial extracts target different elements of the death machinery of mammalian cells.
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Sletta H, Degnes KF, Herfindal L, Klinkenberg G, Fjærvik E, Zahlsen K, Brunsvik A, Nygaard G, Aachmann FL, Ellingsen TE, Døskeland SO, Zotchev SB. Anti-microbial and cytotoxic 1,6-dihydroxyphenazine-5,10-dioxide (iodinin) produced by Streptosporangium sp. DSM 45942 isolated from the fjord sediment. Appl Microbiol Biotechnol 2013; 98:603-10. [PMID: 24158735 DOI: 10.1007/s00253-013-5320-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2013] [Revised: 10/03/2013] [Accepted: 10/05/2013] [Indexed: 10/26/2022]
Abstract
Phenazine natural products/compounds possess a range of biological activities, including anti-microbial and cytotoxic, making them valuable starting materials for drug development in several therapeutic areas. These compounds are biosynthesized almost exclusively by eubacteria of both terrestrial and marine origins from erythrose 4-phosphate and phosphoenol pyruvate via the shikimate pathway. In this paper, we report isolation of actinomycete bacteria from marine sediment collected in the Trondheimfjord, Norway. Screening of the isolates for biological activity produced several "hits", one of which was followed up by identification and purification of the active compound from the actinomycete bacterium Streptosporangium sp. The purified compound, identified as 1,6-dihydroxyphenazine-5,10-dioxide (iodinin), was subjected to extended tests for biological activity against bacteria, fungi and mammalian cells. In these tests, the iodinin demonstrated high anti-microbial and cytotoxic activity, and was particularly potent against leukaemia cell lines. This is the first report on the isolation of iodinin from a marine-derived Streptosporangium.
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Affiliation(s)
- Håvard Sletta
- SINTEF Materials and Chemistry, Department of Biotechnology, Sem Sælands vei 2a, 7465, Trondheim, Norway
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Catherine Q, Susanna W, Isidora ES, Mark H, Aurélie V, Jean-François H. A review of current knowledge on toxic benthic freshwater cyanobacteria--ecology, toxin production and risk management. WATER RESEARCH 2013; 47:5464-79. [PMID: 23891539 DOI: 10.1016/j.watres.2013.06.042] [Citation(s) in RCA: 201] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2013] [Revised: 06/19/2013] [Accepted: 06/21/2013] [Indexed: 05/12/2023]
Abstract
Benthic cyanobacteria are found globally in plethora of environments. Although they have received less attention than their planktonic freshwater counterparts, it is now well established that they produce toxins and reports of their involvement in animal poisonings have increased markedly during the last decade. Most of the known cyanotoxins have been identified from benthic cyanobacteria including: the hepatotoxic microcystins, nodularins and cylindrospermopsins, the neurotoxic saxitoxins, anatoxin-a and homoanatoxin-a and dermatotoxins, such as lyngbyatoxin. In most countries, observations of toxic benthic cyanobacteria are fragmented, descriptive and in response to animal toxicosis events. Only a limited number of long-term studies have aimed to understand why benthic proliferations occur, and/or how toxin production is regulated. These studies have shown that benthic cyanobacterial blooms are commonly a mixture of toxic and non-toxic genotypes and that toxin concentrations can be highly variable spatially and temporally. Physiochemical parameters responsible for benthic proliferation vary among habitat type with physical disturbance (e.g., flow regimes, wave action) and nutrients commonly identified as important. As climatic conditions change and anthropogenic pressures on waterways increase, it seems likely that the prevalence of blooms of benthic cyanobacteria will increase. In this article we review current knowledge on benthic cyanobacteria: ecology, toxin-producing species, variables that regulate toxin production and bloom formation, their impact on aquatic and terrestrial organisms and current monitoring and management strategies. We suggest research needs that will assist in filling knowledge gaps and ultimately allow more robust monitoring and management protocols to be developed.
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Affiliation(s)
- Quiblier Catherine
- MNHN, UMR 7245, 57 rue Cuvier, CP39, 75231 Paris Cedex 05, France; Université Paris Diderot, 5 rue T. Mann, 75013 Paris, France.
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Leão PN, Ramos V, Gonçalves PB, Viana F, Lage OM, Gerwick WH, Vasconcelos VM. Chemoecological screening reveals high bioactivity in diverse culturable Portuguese marine cyanobacteria. Mar Drugs 2013; 11:1316-35. [PMID: 23609580 PMCID: PMC3705407 DOI: 10.3390/md11041316] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2013] [Revised: 03/12/2013] [Accepted: 03/27/2013] [Indexed: 11/29/2022] Open
Abstract
Marine cyanobacteria, notably those from tropical regions, are a rich source of bioactive secondary metabolites. Tropical marine cyanobacteria often grow to high densities in the environment, allowing direct isolation of many secondary metabolites from field-collected material. However, in temperate environments culturing is usually required to produce enough biomass for investigations of their chemical constituents. In this work, we cultured a selection of novel and diverse cyanobacteria isolated from the Portuguese coast, and tested their organic extracts in a series of ecologically-relevant bioassays. The majority of the extracts showed activity in at least one of the bioassays, all of which were run in very small scale. Phylogenetically related isolates exhibited different activity profiles, highlighting the value of microdiversity for bioprospection studies. Furthermore, LC-MS analyses of selected active extracts suggested the presence of previously unidentified secondary metabolites. Overall, the screening strategy employed here, in which previously untapped cyanobacterial diversity was combined with multiple bioassays, proved to be a successful strategy and allowed the selection of several strains for further investigations based on their bioactivity profiles.
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Affiliation(s)
- Pedro N. Leão
- CIMAR/CIIMAR—Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Rua dos Bragas 177, Porto 4050-123, Portugal; E-Mails: (V.R.); (P.B.G.); (V.M.V.)
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +351-223-401-837; Fax: +351-223-390-608
| | - Vitor Ramos
- CIMAR/CIIMAR—Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Rua dos Bragas 177, Porto 4050-123, Portugal; E-Mails: (V.R.); (P.B.G.); (V.M.V.)
| | - Patrício B. Gonçalves
- CIMAR/CIIMAR—Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Rua dos Bragas 177, Porto 4050-123, Portugal; E-Mails: (V.R.); (P.B.G.); (V.M.V.)
| | - Flávia Viana
- Department of Biology, Faculty of Sciences, University of Porto, Rua do Campo Alegre, Porto 4169-007, Portugal; E-Mails: (F.V.); (O.M.L.)
| | - Olga M. Lage
- CIMAR/CIIMAR—Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Rua dos Bragas 177, Porto 4050-123, Portugal; E-Mails: (V.R.); (P.B.G.); (V.M.V.)
- Department of Biology, Faculty of Sciences, University of Porto, Rua do Campo Alegre, Porto 4169-007, Portugal; E-Mails: (F.V.); (O.M.L.)
| | - William H. Gerwick
- Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA 92093, USA; E-Mail:
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Vitor M. Vasconcelos
- CIMAR/CIIMAR—Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Rua dos Bragas 177, Porto 4050-123, Portugal; E-Mails: (V.R.); (P.B.G.); (V.M.V.)
- Department of Biology, Faculty of Sciences, University of Porto, Rua do Campo Alegre, Porto 4169-007, Portugal; E-Mails: (F.V.); (O.M.L.)
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Oftedal L, Myhren L, Jokela J, Gausdal G, Sivonen K, Døskeland SO, Herfindal L. The lipopeptide toxins anabaenolysin A and B target biological membranes in a cholesterol-dependent manner. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2012; 1818:3000-9. [PMID: 22842546 DOI: 10.1016/j.bbamem.2012.07.015] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2012] [Revised: 06/29/2012] [Accepted: 07/19/2012] [Indexed: 11/26/2022]
Abstract
The two novel cyanobacterial cyclic lipopeptides, anabaenolysin (Abl) A and B permeabilised mammalian cells, leading to necrotic death. Abl A was a more potent haemolysin than other known biodetergents, including digitonin, and induced discocyte-echinocyte transformation in erythrocytes. The mitochondria of the dead cells appeared intact with regard to both ultrastructure and membrane potential. Also isolated rat liver mitochondria were resistant to Abl, judged by their ultrastructure and lack of cytochrome c release. The sparing of the mitochondria could be related to the low cholesterol content of their outer membrane. In fact, a supplement of cholesterol in liposomes sensitised them to Abl. In contrast, the prokaryote-directed cyclic lipopeptide surfactin lysed preferentially non-cholesterol-containing membranes. In silico comparison of the positions of relevant functional chemical structures revealed that Abl A matched poorly with surfactin in spite of the common cyclic lipopeptide structure. Abl A and the plant-derived glycolipid digitonin had, however, predicted overlaps of functional groups, particularly in the cholesterol-binding tail of digitonin. This may suggest independent evolution of Abl and digitonin to target eukaryotic cholesterol-containing membranes. Sub-lytic concentrations of Abl A or B allowed influx of propidium iodide into cells without interfering with their long-term cell viability. The transient permeability increase allowed the influx of enough of the cyanobacterial cyclic peptide toxin nodularin to induce apoptosis. The anabaenolysins might therefore not only act solely as lysins, but also as cofactors for the internalisation of other toxins. They represent a potent alternative to digitonin to selectively disrupt cholesterol-containing biological membranes.
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Affiliation(s)
- Linn Oftedal
- Department of Biomedicine, University of Bergen, Norway
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Jokela J, Oftedal L, Herfindal L, Permi P, Wahlsten M, Døskeland SO, Sivonen K. Anabaenolysins, novel cytolytic lipopeptides from benthic Anabaena cyanobacteria. PLoS One 2012; 7:e41222. [PMID: 22829929 PMCID: PMC3400675 DOI: 10.1371/journal.pone.0041222] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2012] [Accepted: 06/19/2012] [Indexed: 11/26/2022] Open
Abstract
Two novel cyclic lipopeptides, anabaenolysin A and anabaenolysin B, were isolated from two benthic cyanobacterial strains of the genus Anabaena. This novel class of cyanobacterial lipopeptides has a general structure of a small peptide ring consisting of four amino acids from which two are proteinogenic and two unusual; glycine1, glycine2, 2-(3-amino-5-oxytetrahydrofuran-2-yl)-2-hydroxyacetic acid3 and a long unsaturated C18 β-amino acid4 with a conjugated triene structure. They are distinguished by the presence of a conjugated dienic structure in the C18 β-amino acid present in anabaenolysin A but not in anabaenolysin B. Conjugated triene structure generates a typical UV spectrum for anabaenolysins for easy recognition. Anabaenolysin A constituted up to 400 ppm of the cyanobacterial dry weight. We found evidence of thirteen variants of anabaenolysins in one cyanobacterial strain. This suggests that the anabaenolysins are an important class of secondary metabolites in benthic Anabaena cyanobacteria. Both anabaenolysin A and B had cytolytic activity on a number of mammalian cell lines.
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Affiliation(s)
- Jouni Jokela
- Division of Microbiology, Department of Food and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - Linn Oftedal
- Department of Biomedicine, University of Bergen, Bergen, Norway
| | - Lars Herfindal
- Department of Biomedicine, University of Bergen, Bergen, Norway
- Translational Signaling Group, Haukeland University Hospital, Bergen, Norway
| | - Perttu Permi
- Program in Structural Biology and Biophysics, Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Matti Wahlsten
- Division of Microbiology, Department of Food and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | | | - Kaarina Sivonen
- Division of Microbiology, Department of Food and Environmental Sciences, University of Helsinki, Helsinki, Finland
- * E-mail:
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12
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Herfindal L, Myhren L, Kleppe R, Krakstad C, Selheim F, Jokela J, Sivonen K, Døskeland SO. Nostocyclopeptide-M1: a potent, nontoxic inhibitor of the hepatocyte drug transporters OATP1B3 and OATP1B1. Mol Pharm 2011; 8:360-7. [PMID: 21214185 DOI: 10.1021/mp1002224] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
We have isolated a novel cyanobacterial cyclic peptide (nostocyclopeptide M1; Ncp-M1) that blocks the hepatotoxic action of microcystin (MC) and nodularin (Nod). We show here that Ncp-M1 is nontoxic to primary hepatocytes in long-term culture. Ncp-M1 does not affect any known intracellular targets or pathways involved in MC action, like protein phosphatases, CaM-KII, or ROS-dependent cell death effectors. In support of this conclusion Ncp-M1 had no protective effect when microinjected into cells. Rather, the antitoxin effect was solely due to blocked hepatocyte uptake of MC and Nod. The hepatic uptake of MC and Nod is mainly via the closely related organic anion transporters OATP1B1 and OATP1B3, which also mediate hepatic transport of endogenous metabolites and hormones as well as drugs. OATP1B3 is also expressed in some aggressive cancers, where it confers apoptosis resistance. We show that Ncp-M1 inhibits transport through OATP1B3 and OATP1B1 expressed in HEK293 cells. The Ncp-M1 molecule has several nonproteinogenic amino acids and an imino bond, which hamper its synthesis. Moreover, a cyclic all L-amino acid heptapeptide analogue of Ncp-M1 also inhibits the OATP1B1/1B3 transporters, and with higher OATP1B3 preference than Ncp-M1 itself. The nontoxic Ncp-M1 and its synthetic cyclic peptide analogues thus provide new tools to probe the role of OATB1B1/1B3 mediated drug and metabolite transport in liver and cancer cells. They can also serve as scaffolds to design new, exopeptidase resistant OATP1B3-specific modulators.
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Affiliation(s)
- Lars Herfindal
- Department of Biomedicine, University of Bergen, Jonas Lies vei 91, 5009 Bergen, Norway
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13
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Jokela J, Herfindal L, Wahlsten M, Permi P, Selheim F, Vasconçelos V, Døskeland SO, Sivonen K. A novel cyanobacterial nostocyclopeptide is a potent antitoxin against microcystins. Chembiochem 2010; 11:1594-9. [PMID: 20575133 DOI: 10.1002/cbic.201000179] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Cyanobacterial hepatotoxins (microcystins and nodularins) cause numerous animal poisonings worldwide each year and are threats to human health. However, we found that extracts from several cyanobacteria isolates failed to induce hepatotoxicity even if they contained high concentrations of the liver toxin microcystin. The antitoxic activity abolishes all morphological hallmarks of microcystin-induced apoptosis, and therefore invalidates cell-based assays of the microcystin content of bloom-forming cyanobacteria. The antitoxin was purified from a cyanobacterial isolate (Nostoc sp. XSPORK 13A) from the Baltic Sea, and the activity was shown to reside in a novel cyclic peptide of the nostocyclopeptide family (nostocyclopeptide M1, Ncp-M1) that consists of seven amino acids (Tyr1-Tyr2-D-HSe3-L-Pro4-L-Val5-(2S,4S)-4-MPr6-Tyr7; MW=881) with an imino linkage between Tyr1 and Tyr7. Ncp-M1 did not compete with labelled microcystin for binding to protein phosphatase 2A; this explains why the antitoxin did not interfere with phosphatase-based microcystin assays. Currently used agents that interfere with microcystin action, such as inhibitors of ROS formation, microcystin uptake and Cam-kinase activity, are themselves inherently toxic. Since Ncp-M1 is potent and nontoxic it promises to become a useful mechanistic tool as soon as its exact cellular target is elucidated.
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Affiliation(s)
- Jouni Jokela
- Department of Food and Environmental Sciences, Division of Microbiology, University of Helsinki, P. O. Box 56, 00014 Helsinki, Finland
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14
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Oftedal L, Selheim F, Wahlsten M, Sivonen K, Døskeland SO, Herfindal L. Marine benthic cyanobacteria contain apoptosis-inducing activity synergizing with daunorubicin to kill leukemia cells, but not cardiomyocytes. Mar Drugs 2010; 8:2659-72. [PMID: 21116413 PMCID: PMC2992999 DOI: 10.3390/md8102659] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2010] [Revised: 10/06/2010] [Accepted: 10/12/2010] [Indexed: 12/16/2022] Open
Abstract
The potential of marine benthic cyanobacteria as a source of anticancer drug candidates was assessed in a screen for induction of cell death (apoptosis) in acute myeloid leukemia (AML) cells. Of the 41 marine cyanobacterial strains screened, more than half contained cell death-inducing activity. Several strains contained activity against AML cells, but not against non-malignant cells like hepatocytes and cardiomyoblasts. The apoptotic cell death induced by the various strains could be distinguished by the role of caspase activation and sensitivity to the recently detected chemotherapy-resistance-associated prosurvival protein LEDGF/p75. One strain (M44) was particularly promising since its activity counteracted the protective effect of LEDGF/p75 overexpressed in AML cells, acted synergistically with the anthracycline anticancer drug daunorubicin in AML cells, and protected cardiomyoblasts against the toxic effect of anthracyclines. We conclude that culturable benthic marine cyanobacteria from temperate environments provide a promising and hitherto underexploited source for novel antileukemic drugs.
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MESH Headings
- Adaptor Proteins, Signal Transducing/metabolism
- Animals
- Antibiotics, Antineoplastic/pharmacology
- Antineoplastic Combined Chemotherapy Protocols/pharmacology
- Apoptosis/drug effects
- Blood Platelets/drug effects
- Blood Platelets/physiology
- Cardiotonic Agents/pharmacology
- Caspases/metabolism
- Cell Line, Tumor
- Cyanobacteria/chemistry
- Cyanobacteria/metabolism
- Daunorubicin/pharmacology
- Drug Resistance, Neoplasm
- Drug Screening Assays, Antitumor
- Drug Synergism
- Hepatocytes/drug effects
- Hepatocytes/metabolism
- Leukemia, Myeloid, Acute/drug therapy
- Leukemia, Myeloid, Acute/metabolism
- Leukemia, Myeloid, Acute/pathology
- Myocytes, Cardiac/drug effects
- Myocytes, Cardiac/metabolism
- Rats
- Seawater/microbiology
- Thionucleotides/metabolism
- Transcription Factors/metabolism
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Affiliation(s)
- Linn Oftedal
- Department of Biomedicine, University of Bergen, Jonas Lies vei 91, 5009 Bergen, Norway; E-Mails: (L.O.); (F.S.); (S.O.D.)
| | - Frode Selheim
- Department of Biomedicine, University of Bergen, Jonas Lies vei 91, 5009 Bergen, Norway; E-Mails: (L.O.); (F.S.); (S.O.D.)
- Proteomic Unit at the University of Bergen, Jonas Lies vei 91, 5009 Bergen, Norway
| | - Matti Wahlsten
- Department of Food and Environmental Sciences, University of Helsinki, P. O. Box 56, 00014 Helsinki, Finland; E-Mails: (M.W.); (K.S.)
| | - Kaarina Sivonen
- Department of Food and Environmental Sciences, University of Helsinki, P. O. Box 56, 00014 Helsinki, Finland; E-Mails: (M.W.); (K.S.)
| | - Stein Ove Døskeland
- Department of Biomedicine, University of Bergen, Jonas Lies vei 91, 5009 Bergen, Norway; E-Mails: (L.O.); (F.S.); (S.O.D.)
| | - Lars Herfindal
- Department of Biomedicine, University of Bergen, Jonas Lies vei 91, 5009 Bergen, Norway; E-Mails: (L.O.); (F.S.); (S.O.D.)
- Translational Signalling group, Haukeland Univ. Hospital, Jonas Lies vei 91, 5009 Bergen, Norway
- * Author to whom correspondence should be addressed; E-Mail: ; Tel.: +47-55 58 63 81; Fax: +47-55 58 63 60
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15
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Oftedal L, Skjærven KH, Coyne RT, Edvardsen B, Rohrlack T, Skulberg OM, Døskeland SO, Herfindal L. The apoptosis-inducing activity towards leukemia and lymphoma cells in a cyanobacterial culture collection is not associated with mouse bioassay toxicity. J Ind Microbiol Biotechnol 2010; 38:489-501. [PMID: 20689978 PMCID: PMC3062024 DOI: 10.1007/s10295-010-0791-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2010] [Accepted: 07/21/2010] [Indexed: 11/29/2022]
Abstract
Cyanobacteria (83 strains and seven natural populations) were screened for content of apoptosis (cell death)-inducing activity towards neoplastic cells of the immune (jurkat acute T-cell lymphoma) and hematopoetic (acute myelogenic leukemia) lineage. Apoptogenic activity was frequent, even in strains cultured for decades, and was unrelated to whether the cyanobacteria had been collected from polar, temperate, or tropic environments. The activity was more abundant in the genera Anabaena and Microcystis compared to Nostoc, Phormidium, Planktothrix, and Pseudanabaena. Whereas the T-cell lymphoma apoptogens were frequent in organic extracts, the cell death-inducing activity towards leukemia cells resided mainly in aqueous extracts. The cyanobacteria were from a culture collection established for public health purposes to detect toxic cyanobacterial blooms, and 54 of them were tested for toxicity by the mouse bioassay. We found no correlation between the apoptogenic activity in the cyanobacterial isolates with their content of microcystin, nor with their ability to elicit a positive standard mouse bioassay. Several strains produced more than one apoptogen, differing in biophysical or biological activity. In fact, two strains contained microcystin in addition to one apoptogen specific for the AML cells, and one apoptogen specific for the T-cell lymphoma. This study shows the potential of cyanobacterial culture collections as libraries for bioactive compounds, since strains kept in cultures for decades produced apoptogens unrelated to the mouse bioassay detectable bloom-associated toxins.
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Affiliation(s)
- Linn Oftedal
- Department of Biomedicine, University of Bergen, Jonas Lies Vei 91, 5009 Bergen, Norway
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16
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Marine benthic diatoms contain compounds able to induce leukemia cell death and modulate blood platelet activity. Mar Drugs 2009; 7:605-23. [PMID: 20098602 PMCID: PMC2810217 DOI: 10.3390/md7040605] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2009] [Revised: 11/16/2009] [Accepted: 11/17/2009] [Indexed: 11/16/2022] Open
Abstract
In spite of the high abundance and species diversity of diatoms, only a few bioactive compounds from them have been described. The present study reveals a high number of mammalian cell death inducing substances in biofilm-associated diatoms sampled from the intertidal zone. Extracts from the genera Melosira, Amphora, Phaeodactylum and Nitzschia were all found to induce leukemia cell death, with either classical apoptotic or autophagic features. Several extracts also contained inhibitors of thrombin-induced blood platelet activation. Some of this activity was caused by a high content of adenosine in the diatoms, ranging from 0.07 to 0.31 μg/mg dry weight. However, most of the bioactivity was adenosine deaminase-resistant. An adenosine deaminase-resistant active fraction from one of the extracts was partially purified and shown to induce apoptosis with a distinct phenotype. The results show that benthic diatoms typically found in the intertidal zone may represent a richer source of interesting bioactive compounds than hitherto recognized.
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17
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Herfindal L, Kasprzykowski F, Schwede F, Łankiewicz L, Fladmark KE, Łukomska J, Wahlsten M, Sivonen K, Grzonka Z, Jastorff B, Døskeland SO. Acyloxymethyl esterification of nodularin-R and microcystin-LA produces inactive protoxins that become reactivated and produce apoptosis inside intact cells. J Med Chem 2009; 52:5758-62. [PMID: 19705870 DOI: 10.1021/jm900502e] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We report the esterification of the carboxyl groups of the cyclic peptide toxins nodularin-R and microcystin-LA to produce stable diacetoxymethyl and dipropionyloxymethyl ester derivatives. The derivatives had no activity but were reactivated upon esterase treatment. When injected into cells, the acyloxymethyl moieties were cleaved off and apoptosis induced. Linking the acyloxymethyl-ester moiety of these potent toxins to carriers destined for endocytosis paves the way for selective apoptosis induction in target (e.g., cancer) cells.
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Affiliation(s)
- Lars Herfindal
- Translational Signaling Group, Department of Biomedicine, University of Bergen, Jonas Lies Vei 91, N-5009 Bergen, Norway.
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18
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Lankoff A, Sochacki J, Spoof L, Meriluoto J, Wojcik A, Wegierek A, Verschaeve L. Nucleotide excision repair impairment by nodularin in CHO cell lines due to ERCC1/XPF inactivation. Toxicol Lett 2008; 179:101-7. [PMID: 18514445 DOI: 10.1016/j.toxlet.2008.04.008] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2008] [Revised: 04/13/2008] [Accepted: 04/16/2008] [Indexed: 11/19/2022]
Abstract
The problem of toxicity of cyanobacterial toxins is of increasing concern, as the incidence of such blooms grows. Among the toxins, the most abundant in the environment are hepatotoxins known as nodularins and microcystins. These toxins are responsible for almost all known cases of fresh and brackish water intoxication and are responsible for recurrent episodes of human and animal illness and death. Moreover, they are believed to be potent tumor promoters and initiators. However, the mechanisms by which these toxins induce liver cancer are not well understood. The aim of the present study was to determine the effect of nodularin on the kinetics of nucleotide excision repair (NER) in Chinese hamster ovary (CHO) cells exposed to UV radiation. The first set of experiments was performed to define the optimal treatment conditions for nodularin to avoid the possibility of encountering false positive signals in the comet assay due to the apoptogenic activity of nodularin. Based on the analysis of apoptosis, the 6-h treatment time of cells with nodularin (1mug/ml, 10mug/ml and 20mug/ml) was chosen for the alkaline comet assay. The kinetics of NER was determined in CHO cell lines: AA8 (wild-type) and mutant cell lines: UV135 (XPG(-)), UV41 (XPF(-)) and UV20 (ERCC1(-)) exposed to 20J/m(2) UV radiation. The micronucleus assay was performed to determine a residual DNA damage in four cell lines treated with nodularin (10mug/ml) and exposed to equitoxic doses UV radiation. Radiation doses of UV producing 50% of survival for AA8, UV135, UV20 and UV41 cell lines were calculated from UV survival curves. The results show that nodularin impairs the incision/excision step of NER in CHO cells by the ERCC1/XPF inactivation and leads to an increased level of UV-induced cytogenetic DNA damage.
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Affiliation(s)
- A Lankoff
- Department of Radiobiology and Immunology, Institute of Biology, Jan Kochanowski University, ul. Swietokrzyska 15, 25-406 Kielce, Poland.
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19
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Toxin types, toxicokinetics and toxicodynamics. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2008; 619:383-415. [DOI: 10.1007/978-0-387-75865-7_16] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
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20
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Halinen K, Fewer DP, Sihvonen LM, Lyra C, Eronen E, Sivonen K. Genetic diversity in strains of the genus Anabaena isolated from planktonic and benthic habitats of the Gulf of Finland (Baltic Sea). FEMS Microbiol Ecol 2008; 64:199-208. [PMID: 18336556 DOI: 10.1111/j.1574-6941.2008.00461.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Late summer cyanobacterial blooms in the Baltic Sea contain Anabaena sp. together with Nodularia spumigena and Aphanizomenon flos-aquae. Although Anabaena is common especially in the Gulf of Finland, very little is known about its genetic diversity. Here we undertook a molecular phylogenetic study of 68 Anabaena strains isolated from the brackish Gulf of Finland. We sequenced the 16S rRNA genes from 54 planktonic and 14 benthic Anabaena strains, and rbcL and rpoC1 genes from a subset of these strains. Phylogenetic trees showed that Anabaena strains, from both planktonic and benthic habitats, were genetically diverse. Although the Anabaena strains were morphologically diverse, in our study only one genetically valid species was found to exist in the plankton. Evolutionary distances between benthic Anabaena strains were greater than between planktonic strains, suggesting that benthic habitats allow for the maintenance of greater genetic diversity than planktonic habitats. A number of novel lineages containing only sequences obtained in this study were compiled in the phylogenetical analyses. Thus, it seemed that novel lineages of the genus Anabaena may be present in the Baltic Sea. Our results demonstrate that the Baltic Sea Anabaena strains show surprisingly high genetic diversity.
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Affiliation(s)
- Katrianna Halinen
- Department of Applied Chemistry and Microbiology, Viikki Biocenter, University of Helsinki, Finland
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21
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Halinen K, Jokela J, Fewer DP, Wahlsten M, Sivonen K. Direct evidence for production of microcystins by Anabaena strains from the Baltic Sea. Appl Environ Microbiol 2007; 73:6543-50. [PMID: 17766456 PMCID: PMC2075070 DOI: 10.1128/aem.01377-07] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Anabaena is a filamentous, N(2)-fixing, and morphologically diverse genus of cyanobacteria found in freshwater and brackish water environments worldwide. It contributes to the formation of toxic blooms in freshwater bodies through the production of a range of hepatotoxins or neurotoxins. In the Baltic Sea, Anabaena spp. form late summer blooms, together with Nodularia spumigena and Aphanizomenon flos-aquae. It has been long suspected that Baltic Sea Anabaena may produce microcystins. The presence of microcystins has been reported for the coastal regions of the Baltic proper, and a recent report also indicated the presence of the toxin in the open Gulf of Finland. However, at present there is no direct evidence linking Baltic Sea Anabaena spp. to microcystin production. Here we report on the isolation of microcystin-producing strains of the genus Anabaena in the open Gulf of Finland. The dominant microcystin variants produced by these strains included the highly toxic MCYST-LR as well as [d-Asp(3)]MCYST-LR, [d-Asp(3)]MCYST-HtyR, MCYST-HtyR, [d-Asp(3),Dha(7)]MCYST-HtyR, and [Dha(7)]MCYST-HtyR variants. Toxic strains were isolated from the coastal Gulf of Finland as well as from the easternmost open-sea sampling station, where there were lower salinities than at other stations. This result suggests that lower salinity may favor microcystin-producing Anabaena strains. Furthermore, we sequenced 16S rRNA genes and found evidence for pronounced genetic heterogeneity of the microcystin-producing Anabaena strains. Future studies should take into account the potential presence of microcystin-producing Anabaena sp. in the Gulf of Finland.
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Affiliation(s)
- Katrianna Halinen
- Department of Applied Chemistry and Microbiology, P.O. Box 56, Viikki Biocenter (Viikinkaari 9), FIN-00014 University of Helsinki, Finland.
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22
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Sivonen K, Halinen K, Sihvonen LM, Koskenniemi K, Sinkko H, Rantasärkkä K, Moisander PH, Lyra C. Bacterial diversity and function in the Baltic Sea with an emphasis on cyanobacteria. AMBIO 2007; 36:180-5. [PMID: 17520932 DOI: 10.1579/0044-7447(2007)36[180:bdafit]2.0.co;2] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
In this article we summarize the current knowledge of Baltic Sea cyanobacteria, focusing on diversity, toxicity, and nitrogen fixation in the filamentous heterocystous taxa. We also review the recent results of our microbial diversity studies in planktonic and benthic habitats in the Baltic Sea. Based on molecular analyses, we have improved the understanding of cyanobacterial population structure by assessing genetic diversity within species that are morphologically inseparable. Moreover, we have studied microbial functions such as toxin production and nitrogen fixation in situ under different environmental conditions. Phosphorus limitation of bloom-forming, nitrogen-fixing cyanobacteria was clearly verified, emphasizing the importance of continuous efforts to reduce this element in the Baltic Sea. We have designed a rapid and reliable detection method for the toxic cyanobacterium Nodularia spumigena, which can be used to study bloom formation of this important toxin producer.
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Affiliation(s)
- Kaarina Sivonen
- Department of Applied Chemistry and Microbiology, Viikki Biocenter, University of Helsinki, Finland.
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23
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Lankoff A, Wojcik A, Fessard V, Meriluoto J. Nodularin-induced genotoxicity following oxidative DNA damage and aneuploidy in HepG2 cells. Toxicol Lett 2006; 164:239-48. [PMID: 16480838 DOI: 10.1016/j.toxlet.2006.01.003] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2005] [Revised: 01/09/2006] [Accepted: 01/10/2006] [Indexed: 12/12/2022]
Abstract
The problem of toxicity of Nodularia spumigena to animals and people is of increasing concern, as the incidence of such blooms grows. It was shown that nodularin is a liver carcinogen possessing both initiating and tumor-promoting activities. However, the mechanisms by which this toxin damages the DNA and induces liver cancer are not well understood. The aim of the present study was to investigate the DNA damaging properties of nodularin. The effect of different doses of nodularin (1-10 microg/ml) on DNA damage was determined in HepG2 cells after 6, 12, 24 and 48 h of the treatment. The modified comet assay in conjunction with Fpg (ROS-induced DNA damage) and FISH-micronucleus assay (clastogenic and/or aneugenic activities of nodularin) were applied. In addition the occurrence of apoptosis was estimated by the morphological analysis of chromatin condensation and the annexin method using flow cytometry. We found that nodularin induces oxidative DNA damage by oxidation of purines and increases the formation of centromere positive micronuclei due to aneugenic activity. In addition to genotoxic properties, nodularin exerts a cytotoxic activity by inducing apoptosis in HepG2 cells. These results suggest a causative role for nodularin in the process leading to the accumulation of genetic alterations which may be implicated in carcinogenesis.
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Affiliation(s)
- A Lankoff
- Department of Radiobiology and Immunology, Institute of Biology, Swietokrzyska Academy, Swietokrzyska 15, 25-406 Kielce, Poland.
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