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The paralytic shellfish toxin, saxitoxin, enters the cytoplasm and induces apoptosis of oyster immune cells through a caspase-dependent pathway.
- Source :
-
Aquatic toxicology (Amsterdam, Netherlands) [Aquat Toxicol] 2017 Sep; Vol. 190, pp. 133-141. Date of Electronic Publication: 2017 Jul 08. - Publication Year :
- 2017
-
Abstract
- Exposure of the toxin-producing dinoflagellate Alexandrium catenella (A. catenella) was previously demonstrated to cause apoptosis of hemocytes in the oyster species Crassostrea gigas. In this work, a coumarin-labeled saxitoxin appeared to spread throughout the cytoplasm of the hemocytes. PSTs, including saxitoxin, were also shown to be directly responsible for inducing apoptosis in hemocytes, a process dependent on caspase activation and independent of reactive oxygen species (ROS) production. A series of in vitro labelling and microscopy experiments revealed that STX and analogs there of induced nuclear condensation, phosphatidylserine exposure, membrane permeability, and DNA fragmentation of hemocytes. Unlike in vertebrates, gonyautoxin-5 (GTX5), which is present in high concentrations in A. catenella, was found to be more toxic than saxitoxin (STX) to oyster immune cells. Altogether, results show that PSTs produced by toxic dinoflagellates enter the cytoplasm and induce apoptosis of oyster immune cells through a caspase-dependent pathway. Because of the central role of hemocytes in mollusc immune defense, PST-induced death of hemocytes could negatively affect resistance of bivalve molluscs to microbial infection.<br /> (Copyright © 2017 Elsevier B.V. All rights reserved.)
- Subjects :
- Animals
Crassostrea immunology
Crassostrea metabolism
Cytoplasm metabolism
Dinoflagellida metabolism
Hemocytes metabolism
Hemocytes ultrastructure
Reactive Oxygen Species metabolism
Saxitoxin metabolism
Shellfish
Water Pollutants, Chemical metabolism
Apoptosis drug effects
Caspases metabolism
Crassostrea drug effects
Cytoplasm drug effects
Hemocytes drug effects
Saxitoxin toxicity
Water Pollutants, Chemical toxicity
Subjects
Details
- Language :
- English
- ISSN :
- 1879-1514
- Volume :
- 190
- Database :
- MEDLINE
- Journal :
- Aquatic toxicology (Amsterdam, Netherlands)
- Publication Type :
- Academic Journal
- Accession number :
- 28711010
- Full Text :
- https://doi.org/10.1016/j.aquatox.2017.07.001