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Genotoxic effects of the cyanobacterial pentapeptide nodularin in HepG2 cells

A new paper by Stern et al., published in Food and Chemical Toxicology, provides evidence for ROS-mediated genotoxic effects of Nodularin. From the abstract:

“The cyanobacterial pentapeptide nodularin (NOD), mainly produced by genus Nodularia, is a potent inhibitor of protein phosphatases PP1 and PP2A, and causes animal mortality. The few studies available indicate that NOD is a potential non-genotoxic carcinogen. In the present study we evaluated NOD (0.01, 0.1 and 1 μg/ml) genotoxic activity in human hepatoma (HepG2) cells with the comet, γH2AX and cytokinesis block micronucleus cytome assays. In addition, induction of oxidative stress was studied. Moreover changes in the expression of selected genes from the P53 pathway, involved in the response to DNA damage (P53, GADD45α, CDKN1A, MDM2), apoptosis (BAX, BCL2) and oxidative stress (GPX1, GSR, GCLC, CAT, SOD1) were determined using qPCR. Non-cytotoxic concentrations induced time and dose dependant increase in reactive oxygen species (ROS) production and substantially increased the formation of oxidative DNA damage. In addition, elevated formation of micronuclei was detected. For the first time it has been shown that NOD deregulated the mRNA level of DNA damage (CDKN1A, GADD45α) and oxidative stress (GPX1, GSR, GCLC, CAT and SOD1) responsive genes and anti-apoptotic gene BCL2. Our results provide new evidence that NOD genotoxic effects are mediated through ROS production, already at low environmentally relevant concentrations.”

The paper acknowledges CYANOCOST.

Reference:

A. Štern, A. Rotter, M. Novak, M. Filipič, B. Žegura (2019). Genotoxic effects of the cyanobacterial pentapeptide nodularin in HepG2 cells. Food and Chemical Toxicology 124, 349-358. https://doi.org/10.1016/j.fct.2018.12.019

A review of BMAA and its isomeric amino acids in cyanobacteria and cyanobacteria -based food supplements

A review paper on occurrence of BMAA and related compounds in cyanobacteria and food supplements by was recently published by Manolidi et al. in Journal of Hazardous Materials.

“The review critically discusses existing reports regarding the occurrence of BMAA, DAB and AEG in cyanobacteria and cyanobacteria-based food supplements. It is shown that inconsistencies in reported results could be attributed to performance of different methods of extraction and analysis applied and in ambiguities regarding determination of soluble and bound fractions of the compounds. The critical aspect of this review aims to grow awareness of human intake of neurotoxic amino acids, while results presented in literature concerning dietary supplements aim to promote further research, quality control as well as development of guidelines for cyanotoxins in food products.”

The review paper acknowledges CYANOCOST.

Reference:

Korina Manolidi, Theodoros M. Triantis, Triantafyllos Kaloudis, Anastasia Hiskia (2019). Neurotoxin BMAA and its isomeric amino acids in cyanobacteria and cyanobacteria-based food supplements. Journal of Hazardous Materials 365, 346-365. https://doi.org/10.1016/j.jhazmat.2018.10.084

The European multi-lake survey dataset is published in Scientific Data.

The European Multi Lake Survey (EMLS) in summer 2015 was an initiative among scientists from 27 countries to collect and analyse lake physical, chemical and biological variables in a fully standardized manner. The first product of the European Multi Lake Survey (EMLS) was published by Mantzouki et al. (2018) in Toxins. Following this publication, the dataset of in-situ lake variables along with nutrient, pigment and cyanotoxin data of 369 lakes in Europe, is now published in Scientific Data (Mantzouki et al. 2018). The data can be found and downloaded from the Environmental Data Portal (EDI). EMLS was coordinated by Evi Manzouki and Bas Ibelings from the University of Geneva, and supported by COST Actions Netlake and CYANOCOST.

References:

  1. E. Mantzouki et al. (2018). A European Multi Lake Survey dataset of environmental variables, phytoplankton pigments and cyanotoxins. Scientific Data 5, 180226. https://doi.org/10.1038/sdata.2018.226 .
  2. Data citation: Mantzouki, E. et al. (2018). Environmental Data Initiative https://doi.org/10.6073/pasta/dabc352040fa58284f78883fa9debe37

The Oxford Word of the Year 2018 is… “toxic”.

The Oxford Word of the Year 2018 is… “toxic”.

From the article published by Oxford Dictionaries:

“Data show that, along with a 45% rise in the number of times it has been looked up on oxforddictionaries.com, over the last year the word toxic has been used in an array of contexts, both in its literal and more metaphorical senses.”

“One of the many environmental issues discussed this year has been the toxic algae disaster in Florida, US. Thanks to a central role in the state’s Senate mid-terms race, toxic algae garnered so much commentary that ‘algae’ featured as the ninth-most frequently seen toxic collocate for 2018.

Link to the article.

 

Occurrence and diversity of cyanotoxins in Greek lakes

From the abstract of a recent paper published by Christophoridis et al. in Scientific Reports:

“Toxic cyanobacteria occur in Greek surface water bodies. However, studies on the occurrence of cyanotoxins (CTs) are often limited to mainly microcystins (MCs), with use of screening methods, such as ELISA, that are not conclusive of the chemical structure of the CT variants and can be subject to false positive results. A multi-lake survey in Greece (14 lakes) was conducted in water and biomass, targeted to a wide range of multi-class CTs including MCs, nodularin-R (NOD), cylindrospermopsin (CYN), anatoxin-a (ANA-a) and saxitoxins (STXs), using multi-class/variant LC-MS/MS analytical workflows, achieving sensitive detection, definitive identification and accurate quantitation. A wide variety of CTs (CYN, ANA-a, STX, neoSTX, dmMC-RR, MC-RR, MC-YR, MC-HtyR, dm3MC-LR, MC-LR, MC-HilR, MC-WR, MC-LA, MC-LY, MC-LW and MC-LF), were detected, with MCs being the most commonly occurring. In biomass, MC-RR was the most abundant toxin, reaching 754 ng mg−1 dw, followed by MC-LR (458 ng mg−1 dw). CYN and ANA-a were detected for the first time in the biomass of Greek lakes at low concentrations and STXs in lakes Trichonis, Vistonis and Petron. The abundance and diversity of CTs were also evaluated in relation to recreational health risks, in a case study with a proven history of MCs (Lake Kastoria).”

The study was funded by the project ARISTEIA: “CYANOWATER” coordinated by A. Hiskia (NCSR Demokritos) and it also acknowledges CYANOCOST.

Reference:

Christophoros Christophoridis, Sevasti-Kiriaki Zervou, Korina Manolidi, Matina Katsiapi, Maria Moustaka-Gouni, Triantafyllos Kaloudis, Theodoros M. Triantis, Anastasia Hiskia* (2018). Occurrence and diversity of cyanotoxins in Greek lakes. Scientific Reports volume 8, Article number: 17877. https://doi.org/10.1038/s41598-018-35428-x

 

 

 

2nd Announcement : ICTC11, Krakow, 5-10 May 2019

We would like to inform you of the second announcement and invite all of you to attend the “11th International Conference on Toxic Cyanobacteria” (ICTC 11), which will be held in Kraków, Poland, from 5 to 10 May 2019. All those interested in ICTC 11 will find detailed information about the conference at http://www.ictc11.org.

The deadline for abstract submission is 15 January 2019.

Dariusz Dziga
Iwona Jasser
Mikołaj Kokociński
Joanna Mankiewicz-Boczek
Hanna Mazur-Marzec
Barbara Pawlik-Skowrońska

Local Organizing Committee

Special Issue “Effects of Harmful Cyanobacteria on Ecosystem Functioning, Food Webs, and Water Quality”- Water, MDPI

Dear Colleagues,

Harmful algal blooms (HABs) in frehwaters and partly also in brackish, coastal seas are frequently dominated by cyanobateria. Cyanobacterial blooms are well established as indicators of environmental degradation. Beyond the role as indicators, bloom forming Cyanobacteria by themselves are a serious threat to the functioning of aquatic ecosystems and resources and services provided by aquatic ecosystems. Because of their mechanical properties and the toxicity of several of them, harmful Cyanobacteria may seriously inhibit matter and energy transfer through the food webs. Dense aggregations of cyanobacterial biomass lead to chemical alterations of the water, including pH-changes and a subsequent shift from NH+-ions to toxic NH3, and the release of toxins from live cells and after cell lysis. This, in turn, can lead to animal kills and health hazards for humans via drinking water, consumption of fish, and recreational use. The planned Special Issue should summmarize recent advances in the monitoring, analysis, and prevention of harfmul cyanobacteria and their adverse effects on ecosystem functioning, food webs, and water quality. Among others, possible topics include the effects of cyanobacteria on water chemistry, deep water, and sediment anoxia, grazing inhibition, animal kills, biodiversity, ecological status, human health, and analyses of societal costs.

Prof. Dr. Maria Moustaka-Gouni
Prof. Dr. Ulrich Sommer
Guest Editors

Deadline for manuscript submissions: 30 June 2020

Link to the webpage of the special issue.