A high proportion of Baltic Sea benthic cyanobacterial isolates contain apoptogens able to induce rapid death of isolated rat hepatocytes
To assess the potential hepatotoxicity of benthic cyanobacteria, we isolated 41 strains from the Baltic Sea. The bacteria were differentially extracted with solvents of decreasing polarity. The extracts were tested for ability to induce death of primary rat hepatocytes in suspension culture. Mainly...
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Published in | Toxicon (Oxford) Vol. 46; no. 3; pp. 252 - 260 |
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Main Authors | , , , , , |
Format | Journal Article |
Language | English |
Published |
Oxford
Elsevier Ltd
01.09.2005
Elsevier Science |
Subjects | |
Online Access | Get full text |
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Summary: | To assess the potential hepatotoxicity of benthic cyanobacteria, we isolated 41 strains from the Baltic Sea. The bacteria were differentially extracted with solvents of decreasing polarity. The extracts were tested for ability to induce death of primary rat hepatocytes in suspension culture. Mainly morphological criteria were used to discriminate between cell death with apoptotic features (shrinkage, chromatin hypercondensation, budding) or necrotic features (swelling, loss of plasma membrane integrity). The 24 isolates containing hepatotoxic compounds were of the genus
Anabaena. The non-toxic isolates were mainly
Nostoc and
Calothrix. The toxicity was not due to the known hepatotoxic cyanobacterial protein phosphatase inhibitors microcystin or nodularin, as demonstrated by lacking competition with microcystin for PP2A binding. Apoptotic cell death was rapid, being evident from 10 to 60
min after the addition of extract. Sometimes the initial apoptosis was followed by secondary necrosis. Three cyanobacterial extracts produced apoptosis with unusual cell morphology including actin rearrangements. It will be of interest to know if they contain substance(s) acting through novel death pathways. We conclude that benthic
Anabaena cyanobacteria represent a rich source of apoptogenic toxins, presumably directed against competitors or predators in the aquatic environment, but obviously able also to induce cell death in mammalian parenchymal liver cells. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0041-0101 1879-3150 |
DOI: | 10.1016/j.toxicon.2005.04.005 |