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

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.

Special Issue: Advancing Knowledge on Cyanobacterial Blooms in Freshwaters – Water-MDPI

Dear Colleagues,

Cyanobacterial blooms are a water quality problem that has been widely acknowledged to cause detrimental ecological and economic effects in drinking and recreational waters supplies, and fisheries. There is increasing evidence that cyanobacterial blooms have increased globally and are likely to expand in water resources due to climate change. Of most concern are cyanotoxins, along with mechanisms that induce their release and fate in the aquatic envirornment. These secondary metabolites pose a potential hazard to human health and agricultural and aquaculture products directed for animal and human consumption; therefore, strict and reliable control of cyanotoxins is crucial for assessing risk. In this direction, a deeper understanding of the mechanisms that determine cyanobacterial bloom structures and toxin production become a target for managing practices.This Special Issue aims to bring together recent research of multi- and interdisciplinary approaches from the field to the laboratory and back again, driven by working hypotheses based on any aspect from ecological theory to applied research on mitigating cyanobacterial blooms. Of special interest are papers that suggest the use of complementary approaches, from the most recently developed molecular-based methods to more classical approaches and experimental and mathematical modeling regarding factors (abiotic and/or biotic) that control the diversity of not only the key bloom forming cyanobacterial species, but also their interactions to other biota, either in frehswater systems or their adjacent habitats, and their role in preventing and/or promoting cyanobacterial growth and toxin production and/or degradation.

Prof. Dr. Elisabeth (Savi) Vardaka
Prof. Dr. Konstantinos Ar. Kormas
Guest Editors

Deadline for manuscript submissions: 30 November 2019

Link to the Special Issue website (Water-MDPI).

IOC-UNESCO HARMFUL ALGAE NEWS No. 61 is now available!

Harmful Algae News (HAN) is an IOC (UNESCO) newsletter created to respond to the expressed wishes of participants in several IOC workshops on harmful algal blooms, in particular the IOC-SCOR Workshop in Newport, Rhode Island (USA), 2-3 November 1991. Its purpose is to disseminate information on harmful algal events and on research results as well as to announce research and management programmes, conferences, meetings etc. The initial address list included all the participants in the V International Conference on Harmful Algal Blooms. Nowadays, HAN has more than 2000 subscribers.

HARMFUL ALGAE NEWS No. 61 now online @ http://www.e-pages.dk/ku/1401/

Visit the ISSHA webpage for more resources on Harmful Algae.

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

 

New cyanopeptolins with potential medical applications !

Abstract from a recent paper by Hanna Mazur-Marzec et al., published in Marine Drugs:

“Cyanopeptolins (CPs) are one of the most frequently occurring cyanobacterial peptides, many of which are inhibitors of serine proteases. Some CP variants are also acutely toxic to aquatic organisms, especially small crustaceans. In this study, thirteen CPs, including twelve new variants, were detected in the cyanobacterium Nostoc edaphicum CCNP1411 isolated from the Gulf of Gdańsk (southern Baltic Sea). Structural elucidation was performed by tandem mass spectrometry with verification by NMR for CP962 and CP985. Trypsin and chymotrypsin inhibition assays confirmed the significance of the residue adjacent to 3-amino-6-hydroxy-2-piperidone (Ahp) for the activity of the peptides. Arginine-containing CPs (CPs-Arg2) inhibited trypsin at low IC50 values (0.24–0.26 µM) and showed mild activity against chymotrypsin (IC50 3.1–3.8 µM), while tyrosine-containing CPs (CPs-Tyr2) were selectively and potently active against chymotrypsin (IC50 0.26 µM). No degradation of the peptides was observed during the enzyme assays. Neither of the CPs were active against thrombin, elastase or protein phosphatase 1. Two CPs (CP962 and CP985) had no cytotoxic effects on MCF-7 breast cancer cells. Strong and selective activity of the new cyanopeptolin variants makes them potential candidates for the development of drugs against metabolic disorders and other diseases.”

The work was carried out by researchers of  the University of Gdansk (Poland) and Robert Gordon University (Scotland, UK) and acknowledges CYANOCOST.

Reference (open access):

Mazur-Marzec, Hanna; Fidor, Anna; Cegłowska, Marta; Wieczerzak, Ewa; Kropidłowska, Magdalena; Goua, Marie; Macaskill, Jenny; Edwards, Christine (2018).  Cyanopeptolins with Trypsin and Chymotrypsin Inhibitory Activity from the Cyanobacterium Nostoc edaphicum CCNP1411. Marine Drugs 16(7) https://doi.org/10.3390/md16070220

 

Three papers published so far in “Marine Bacterial Toxins” Special Issue. Submissions still open !

Three papers have been published in the Marine Drugs Special Issue “Marine Bacterial Toxins”, that is edited by Prof. Hanna Mazur-Marzec and Dr. Anna Toruńska-Sitarz (University of Gdańsk).

You can have open access to the papers through the Special Issue website:
http://www.mdpi.com/journal/marinedrugs/special_issues/marine_bacterial_toxins

The call for submission of papers for this issue is still open. The submission deadline is 20 December 2018.You can contact the editors if you are planning to submit a paper.