Neuro-apoptogenic and blood platelet targeting toxins in benthic marine cyanobacteria from the Portuguese coast

• Published in: Aquatic toxicology Vol. 74; no. 4; pp. 294 - 306
• Main Authors: Selheim, Frode, Herfindal, Lars, Martins, Rosario, Vasconcelos, Vitor, Døskeland, Stein Ove
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 30.09.2005; Elsevier Science
• Subjects: Animal, plant and microbial ecology; Animals; Aphanothece; Aphanothece sp; Apoptosis - drug effects; Applied ecology; Atlantic Ocean; Bacterial Toxins - metabolism; Bacterial Toxins - toxicity; Benthic cyanobacteria; Biological and medical sciences; Biological Assay; Blood platelets; Cell Extracts - toxicity; Cells, Cultured; Cyanobacteria - chemistry; Ecotoxicology, biological effects of pollution; Fundamental and applied biological sciences. Psychology; General aspects; Marine Toxins - metabolism; Marine Toxins - toxicity; Mice; Neuroblastoma; Platelet Activation - drug effects; Portugal; Species Specificity; Toxic cyanobacteria; Portugal; Atlantic Ocean; ANE, Portugal; PP; ACD; Benthic cyanobacteria; PLC; HRP; TRAP; Neuroblastoma; ECL; Aphanothece sp; GFP; PA; FITC; PMP; PI3K; Blood platelets; PE; Toxic cyanobacteria; Ecotoxicology; Toxicity; Blood; Marine environment; Aquatic environment; Toxin; Cyanobacteria; Bacteria
• ISSN: 0166-445X; 1879-1514
• DOI: 10.1016/j.aquatox.2005.06.005

Six strains of marine cyanobacteria, of which five benthic, were isolated from an area of the Portuguese coast with no known apparent toxic microbial bloom. Five strains were lethal for mice. Four of them produced lethargy and four lead to bleeding. One of the toxic strains was from a genus ( Aphanothece) not previously associated with toxin production. Extracts from four isolates induced SH-SY5Y-neuroblastoma cell apoptosis without affecting the viability of hepatocytes, NRK kidney cells, or fibroblasts. Aqueous extract from four isolates inhibited thrombin-induced blood platelet activation, with decreased P-selectin expression, platelet aggregation and shedding of platelet-derived micro-vesicles. Curiously, platelets treated with organic extracts from two of the cyanobacterial strains formed platelet micro-vesicles, expressed P-selectin on the surface and showed a distinct phosphotyrosine protein pattern, but failed to aggregate. We conclude that low-abundance marine cyanobacteria growing at low rates may be an important source for novel toxins that may be useful to dissect mammalian signalling pathways of apoptosis and platelet function.