Cyanobacterial harmful blooms (CyanoHABs) pose a global ecological problem, and their lipopolysaccharides (LPS) are among the bioactive compounds they release. Previous studies on CyanoHAB-LPS from single cyanobacterial species have shown varying bioactivities in different in vitro cell models. In this study, we isolated LPS from 19 CyanoHAB samples collected at 18 water bodies in the Czech Republic over two consecutive seasons. The proportions of cyanobacteria, Gram-negative bacteria (G-), and other bacteria in the biomass were determined by qPCR, while the cyanobacterial genera were identified using light microscopy. In vitro models of keratinocytes (HaCaT), the intestinal epithelium (co-culture of differentiated Caco-2 cells and peripheral blood mononuclear cells - PBMC), and PBMC alone were treated with isolated LPS at concentrations of 50, 100, and 1 µg/ml, respectively. The endotoxin activities of these concentrations were within the range measured in the aquatic environment. Approximately 85-90% of the samples displayed biological activity. However, the potency of individual LPS effects and response patterns varied across the different in vitro models. Furthermore, the observed activities did not exhibit a clear correlation with the taxonomic composition of the phytoplankton community, the relative share of microbial groups in the biomass, endotoxin activity of the LPS, or LPS migration and staining pattern in SDS-PAGE. These findings suggest that the effects of CyanoHAB-LPS depend on the specific composition and abundance of various LPS structures within the complex environmental sample and their interactions with cellular receptors.

• Klíčová slova
• Cyanobacterial harmful blooms, Enterocytes, Immune cells, Inflammation, Keratinocytes, Lipopolysaccharide,
• MeSH
• biomasa MeSH
• Caco-2 buňky MeSH
• leukocyty mononukleární MeSH
• lidé MeSH
• lipopolysacharidy * toxicita   MeSH
• sinice * MeSH
• škodlivý vodní květ MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• lipopolysacharidy * MeSH

Freshwater cyanobacterial harmful blooms (CyanoHABs) produce a variety of toxic and bioactive compounds including lipopolysaccharides (LPSs). The gastrointestinal tract can be exposed to them via contaminated water even during recreational activities. However, there is no evidence of an effect of CyanoHAB LPSs on intestinal cells. We isolated LPSs of four CyanoHABs dominated by different cyanobacterial species and LPSs of four laboratory cultures representing the respective dominant cyanobacterial genera. Two intestinal and one macrophage cell lines were used to detect in vitro pro-inflammatory activity of the LPS. All LPSs isolated from CyanoHABs and laboratory cultures induced cytokines production in at least one in vitro model, except for LPSs from the Microcystis PCC7806 culture. LPSs isolated from cyanobacteria showed unique migration patterns in SDS-PAGE that were qualitatively distinct from those of endotoxins from Gram-negative bacteria. There was no clear relationship between the biological activity of the LPS and the share of genomic DNA of Gram-negative bacteria in the respective biomass. Thus, the total share of Gram-negative bacteria, or the presence of Escherichia coli-like LPSs, did not explain the observed pro-inflammatory activities. The pro-inflammatory properties of environmental mixtures of LPSs from CyanoHABs indicate their human health hazards, and further attention should be given to their assessment and monitoring.

• Klíčová slova
• cyanobacteria, cyanobacterial harmful bloom, inflammation, intestine, lipopolysaccharide, macrophage,
• MeSH
• endotoxiny metabolismus   MeSH
• lidé MeSH
• lipopolysacharidy farmakologie   MeSH
• Microcystis * MeSH
• sinice * metabolismus   MeSH
• škodlivý vodní květ MeSH
• sladká voda mikrobiologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• endotoxiny MeSH
• lipopolysacharidy MeSH

Massive toxic blooms of cyanobacteria represent a major threat to water supplies worldwide. Here, the biological activities of lipopolysaccharide (LPS) isolated from Microcystis aeruginosa, the most prominent cyanobacteria in water bloom, were studied. LPS was isolated from complex environmental water bloom samples dominated by M. aeruginosa, and from laboratory cultures of non-axenic as well as axenic M. aeruginosa strains PCC7806 and HAMBI/UHCC130. Employing human blood-based in vitro tests, the LPS isolated from complex water bloom revealed the priming of both major blood phagocyte population monocytes and polymorphonuclear leukocytes documented by the increased surface expression of CD11b and CD66b. This was accompanied by a water bloom LPS-mediated dose-dependent induction of tumor necrosis factor α, interleukin-1β, and interleukin-6 production. In accordance with its priming effects, water bloom LPS induced significant activation of p38 and ERK1/2 kinases, as well as NF-κB phosphorylation, in isolated polymorphonuclear leukocytes. Interestingly, the pro-inflammatory potential of LPS from the axenic strain of M. aeruginosa was not lower compared to that of LPS isolated from non-axenic strains. In contrast to the biological activity, water bloom LPS revealed almost twice higher pyrogenicity levels compared to Escherichia coli LPS, as analyzed by the PyroGene test. Moreover, LPS from the non-axenic culture exhibited higher endotoxin activity in comparison to LPS from axenic strains. Taking the above findings together, M. aeruginosa LPS can contribute to the health risks associated with contamination by complex water bloom mass.

• Klíčová slova
• cyanobacteria, endotoxin, inflammation, leukocytes, lipopolysaccharide, water bloom,
• MeSH
• antigeny CD11b metabolismus   MeSH
• CD antigeny metabolismus   MeSH
• cytokiny krev   MeSH
• eutrofizace MeSH
• GPI-vázané proteiny metabolismus   MeSH
• kultivované buňky MeSH
• laboratoře MeSH
• leukocyty mononukleární účinky léků   metabolismus   MeSH
• lidé MeSH
• lipopolysacharidy toxicita   MeSH
• Microcystis * MeSH
• molekuly buněčné adheze metabolismus   MeSH
• přirozená imunita účinky léků   MeSH
• pyrogeny toxicita   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• antigeny CD11b MeSH
• CD antigeny MeSH
• CEACAM8 protein, human MeSH Prohlížeč
• cytokiny MeSH
• GPI-vázané proteiny MeSH
• ITGAM protein, human MeSH Prohlížeč
• lipopolysacharidy MeSH
• molekuly buněčné adheze MeSH
• pyrogeny MeSH

Toxicity and liver tumor promotion of cyanotoxins microcystins have been extensively studied. However, recent studies document that other metabolites present in the complex cyanobacterial water blooms may also have adverse health effects. In this study we used rat liver epithelial stem-like cells (WB-F344) to examine the effects of cyanobacterial extracts on two established markers of tumor promotion, inhibition of gap-junctional intercellular communication (GJIC) and activation of mitogen-activated protein kinases (MAPKs) - ERK1/2. Extracts of cyanobacteria (laboratory cultures of Microcystis aeruginosa and Aphanizomenon flos-aquae and water blooms dominated by these species) inhibited GJIC and activated MAPKs in a dose-dependent manner (effective concentrations ranging 0.5-5mgd.w./mL). Effects were independent of the microcystin content and the strongest responses were elicited by the extracts of Aphanizomenon sp. Neither pure microcystin-LR nor cylindrospermopsin inhibited GJIC or activated MAPKs. Modulations of GJIC and MAPKs appeared to be specific to cyanobacterial extracts since extracts from green alga Chlamydomonas reinhardtii, heterotrophic bacterium Klebsiella terrigena, and isolated bacterial lipopolysaccharides had no comparable effects. Our study provides the first evidence on the existence of unknown cyanobacterial toxic metabolites that affect in vitro biomarkers of tumor promotion, i.e. inhibition of GJIC and activation of MAPKs.

• MeSH
• aktivace enzymů účinky léků   MeSH
• alkaloidy MeSH
• Aphanizomenon chemie   izolace a purifikace   MeSH
• bakteriální toxiny MeSH
• buněčné linie MeSH
• časové faktory MeSH
• extracelulárním signálem regulované MAP kinasy metabolismus   MeSH
• fosforylace účinky léků   MeSH
• karcinogeny chemie   toxicita   MeSH
• komplexní směsi chemie   toxicita   MeSH
• krysa rodu Rattus MeSH
• mezerový spoj účinky léků   MeSH
• mezibuněčná komunikace účinky léků   MeSH
• Microcystis chemie   izolace a purifikace   MeSH
• mikrocystiny analýza   toxicita   MeSH
• mitogenem aktivované proteinkinasy metabolismus   MeSH
• sinice chemie   izolace a purifikace   MeSH
• sladká voda mikrobiologie   MeSH
• toxiny kmene Cyanobacteria MeSH
• uracil analogy a deriváty   toxicita   MeSH
• vztah mezi dávkou a účinkem léčiva MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• srovnávací studie MeSH
• Geografické názvy
• Česká republika MeSH
• Názvy látek
• alkaloidy MeSH
• bakteriální toxiny MeSH
• cylindrospermopsin MeSH Prohlížeč
• extracelulárním signálem regulované MAP kinasy MeSH
• karcinogeny MeSH
• komplexní směsi MeSH
• mikrocystiny MeSH
• mitogenem aktivované proteinkinasy MeSH
• toxiny kmene Cyanobacteria MeSH
• uracil MeSH