title: Neuro-apoptogenic and blood platelet targeting toxins in benthic marine cyanobacteria from the Portuguese coast.
abstract: 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.
authors.affiliation: Department of Biomedicine, University of Bergen, Jonas Lies vei 91, N-5009 Bergen, Norway.
authors.forename: Frode
authors.initials: F
authors.lastname: Selheim
authors.forename: Lars
authors.initials: L
authors.lastname: Herfindal
authors.forename: Rosario
authors.initials: R
authors.lastname: Martins
authors.forename: Vitor
authors.initials: V
authors.lastname: Vasconcelos
authors.forename: Stein Ove
authors.initials: SO
authors.lastname: Døskeland
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D001267:Atlantic Ocean; D001427:Bacterial Toxins / Q000378:metabolism / Q000633:toxicity*; D001681:Biological Assay; D002457:Cell Extracts / Q000633:toxicity*; D002478:Cells, Cultured; D000458:Cyanobacteria / Q000737:chemistry*; D008387:Marine Toxins / Q000378:metabolism / Q000633:toxicity*; D051379:Mice; D015539:Platelet Activation / Q000187:drug effects*; D011174:Portugal; D013045:Species Specificity
chemical_list: D001427:Bacterial Toxins; D002457:Cell Extracts; D008387:Marine Toxins