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

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

CYANOnews Sep-Oct 2018 issue is out !

The September-October 2018 issue of CYANOnews is out !

It features, among others, an overview of the CyanoTracker project, open special issues related to cyano-research, new papers acknowledging CYANOCOST, job offers and forthcoming events.

You can download it here:

https://cyanocost.files.wordpress.com/2018/10/cyanonews-issue-10-sep-oct-2018.pdf

The next issue will come out in the end of November. You are welcome to send us any posts and info to be included in CYANOnews and in our media (website, facebook, twitter).

Looking forward to ICHA2018 in Nantes,

CYANOCOST

 

Postdoc researcher, Analytical and Environmental Chemistry (Natural Toxins) at Eawag

The Department of Environmental Chemistry (Uchem) of Eawag is offering a position for a Postdoctoral Researcher in Environmental and Analytical Chemistry.
Topic: Natural Toxins

The position is part of our research on natural toxins. Ecosystems and drinking water resources are not only vulnerable towards anthropogenic pollutants but also natural toxins. Bioactive compounds produced by aquatic organisms, such as cyanobacteria, are of particular concern since these are waterborne toxins directly released into surface waters. Cyanobacteria produce a diverse mixture of bioactive compounds beyond the well-known microcystins, yet the potential risk of many cyanobacterial metabolites remains mostly unknown.

The project is led by Dr Elisabeth Janssen (Uchem) in collaboration with Dr Colette vom Berg (Utox). The period of appointment for the Postdoctoral Researcher is 24 months, earliest starting date is January 2019 or as soon as the position can be adequately filled.
Closing date for applications is 15 November 2018.
Details and application form can be found here.

Just published: ICTC10 Special Issue – Journal of Oceanology and Limnology.

The Special Issue of ICTC10 that was held in October 2016 in Wuhan, China is published in Journal of Oceanology and Limnology, Volume 36, Issue 4, July 2018. 

From the Preface article by R. Li, L. Song and P. Orr:

“The 10th nternational Conference on toxic cyanobacteria (ICTC-10) was successfully held during 23–28 Oct. 2016. We were so glad to see much progress made on toxic cyanobacteria and cyanotoxins during past years, and the ICTC does provide a global forum for a wide-ranging communication and discussion of key issues related to cyanobacterial blooms and cyanotoxins. This special issue “Cyanobacteria and cyanotoxins: responses and detection” in Journal of Oceanology and Limnology includes a collection of twelve papers focus on different topics and approaches on diversity, detection and physiological responses of cyanobacterial blooms and cyanotoxins.”

ICTC11 will be held in Krakow, Poland, on 5-10 May 2019.

VIDEO: Tools for Addressing the Risks of Cyanotoxins in Drinking Water

U.S. EPA Office of Ground Water and Drinking water recently released a video that provides an overview of available tools to support proactive planning for cyanotoxin management in drinking water; watch the video here.

Many thanks to Dr. Lesley D’Anglada, US EPA, Editor of the Freshwater HABs Newsletter  for sharing this information.

 

CyanoVir2018 Workshop, held on 3-6 July in Krakow, Poland

A Workshop titled “CyanoVir2018” was held in the Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Kraków, Poland on 3-6 July 2018. The Chairman of Scientific Committee was Dariusz Dziga andal Organizing Committee members were Anna Maksylewicz, Aleksandra Tlałka, Adam Antosiak.

The main topics of CyanoVir2018 were:

– The interaction between marine toxic cyanobacteria and cyanophages
– Adaptation of toxic cyanobacteria to the chill/light stress
– Extraction, isolation and characterization of bioactive metabolites from cyanobacteria
– The analysis and interpretation of MS spectra of cyanobacterial peptides
– The integration of best practices to block cyanobacterial overgrowth
– Terrestrial cyanobacteria and cyanobacterial secondary metabolites as biomarkers for paleoclimatic reconstruction
– Analysis of RNA-seq data and bacteriophage genome annotations

Invited speakers included J. Meriluoto, Z. Svircev, H. Mazur-Marzec, M. Antoniou, A. Toruńska, K. Kvederavičiūtė, E. Šimoliūnas, N. Tokodi, D. Drobac and Krzysztof Pyrć.

You can download the flyer of Cyanovir 2018 here.

 

 

CyanoSED: A Workshop on Benthic Cyanobacteria and Cyanotoxins, August 6 & 7, in Cincinnati, Ohio.

On August 6 and 7, 2018, CyanoSED: A Workshop on Benthic Cyanobacteria and Cyanotoxins will take place at EPA-Cincinnati.

The workshop is organized by Dr. Kaytee Pokrzywinski (U.S. Army Corps of Engineers), Dr. Timothy Davis (Bowling Green State University), Dr. Susie Wood (The Cawthron Institute) and Dr. Jim Lazorchak (EPA, ORD, NERL).

The goals of the workshop are to identify knowledge gaps and prioritize research needs on issues surrounding benthic cyanobacteria and it will feature presentations from experts in the field and discussions on those presented topics.

 Symposium Objectives:

  1. Understand current research in benthic/sediment-associated HABs related to benthic mat-forming (including attached, periphytic and filamentous) cyanobacteria and benthic-pelagic (planktonic) coupling of bloom events.
  2. Identify knowledge gaps and topic areas worth pursing in more detail.
  3. Facilitate engagement among federal, local and state government agencies; academic institutions; and industry partners to continue coordination and collaboration on sediment/benthic-associated HABs issues.
  4. Effectively disseminate workshop results by facilitating publication of research priorities and detailed key discussions developed through this workshop.

This information was shared by Dr. Jim Lazorchak (EPA, ORD, NERL).

 

First report of cyanotoxins in Lake Yerevan, Armenia.

Abstract of a paper from a collaboration within CYANCOST (Armenia, USA, Greece), that was authored by  Minasyan et al. and published in Toxicon:

“This paper presents the first report of cyanobacteria and cyanotoxins from the South Caucasus region, in particular from Lake Yerevan (Armenia). Microcystis, Dolichospermum and Planktothrix were the key genera identified during the growing season. A trend of a remarkable increase in cyanobacterial densities was observed from 2012 to 2013 exhibiting bloom formation in June (by Nostoc linckia) with the highest values in June and August 2013, reaching up to 695.9*103 cells mL−1. Seasonal dependence of cyanobacterial density on temperature, and temperature as a driver for cyanobacterial cells growth and development were suggested. Biogenic nutrients were identified as co-drivers determining species richness and dominance, as well as the distribution of phytoplankton in different parts of the reservoir.

Cyanotoxin concentrations in the filtered biomass were reported during July 2012 for both stations of the reservoir (left and right bank). Microcystin-RR (MC-RR) was the most abundant and the most frequently observed cyanotoxin. Lower MC-LR concentrations were identified in all samples from both stations, with the highest values observed at the right bank in July 2012. [D-Asp3]MC-RR, MC-YR, MC-HtyR, [D-Asp3]MC-LR, MC-HilR, MC-WR, MC-LY and MC-LW were also identified in trace levels. Anatoxin-a (ANA) was reported in the samples from both stations during August 2012. Cylindrospermopsin (CYN) was present in trace concentrations in samples from both stations during July and in the sample from the left bank during September.”

This paper acknowledges CYANOCOST.

Reference:

Arevik Minasyan, Christophoros Christophoridis, Alan E. Wilson, Sevasti-Kiriaki Zervou, Triantafyllos Kaloudis, Anastasia Hiskia (2018). Diversity of cyanobacteria and the presence of cyanotoxins in the epilimnion of Lake Yerevan (Armenia). Toxicon 150, 28-38.
https://doi.org/10.1016/j.toxicon.2018.04.021.