title: Diatom-derived oxylipins induce cell death in sea urchin embryos activating caspase-8 and caspase 3/7.
abstract: Diatoms are an important class of unicellular algae that produce bioactive secondary metabolites with cytotoxic activity collectively termed oxylipins, including polyunsaturated aldehydes (PUAs), hydroxyacids (HEPEs), oxo-acids and epoxyalcohols. Previous results showed that at higher concentrations, the PUA decadienal induced apoptosis on copepods and sea urchin embryos via caspase-3 activation; at lower concentrations decadienal affected the expression levels of the caspase-8 gene in embryos of the sea urchin Paracentrotus lividus. In the present work, we studied the effects of other common oxylipins produced by diatoms: two PUAs (heptadienal and octadienal) and four hydroxyacids (5-, 9- 11- and 15-HEPE) on P. lividus cell death and caspase activities. Our results showed that (i) at higher concentrations PUAs and HEPEs induced apoptosis in sea urchin embryos, detected by microscopic observation and through the activation of caspase-3/7 and caspase-8 measured by luminescent assays; (ii) at low concentrations, PUAs and HEPEs affected the expression levels of caspase-8 and caspase-3/7 (isolated for the first time here in P. lividus) genes, detected by Real Time qPCR. These findings have interesting implications from the ecological point of view, given the importance of diatom blooms in nutrient-rich aquatic environments.
authors.affiliation: Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Napoli, Italy.
authors.forename: Nadia
authors.initials: N
authors.lastname: Ruocco
authors.affiliation: Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Napoli, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Varrella
authors.affiliation: Department of Integrative Marine Ecology, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Napoli, Italy.
authors.forename: Giovanna
authors.initials: G
authors.lastname: Romano
authors.affiliation: Department of Integrative Marine Ecology, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Napoli, Italy.
authors.forename: Adrianna
authors.initials: A
authors.lastname: Ianora
authors.affiliation: Faculty of Science and Technology, C227 Christchurch House, Bournemouth University, Talbot Campus, Poole, UK.
authors.forename: Matt G
authors.initials: MG
authors.lastname: Bentley
authors.affiliation: Dipartimento di Medicina Molecolare e Biotecnologie Mediche, Università di Napoli Federico II, Napoli, Italy.
authors.forename: Domenico
authors.initials: D
authors.lastname: Somma
authors.affiliation: Dipartimento di Medicina Molecolare e Biotecnologie Mediche, Università di Napoli Federico II, Napoli, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Leonardi
authors.affiliation: Istituto di Endocrinologia e Oncologia Sperimentale, CNR, Napoli, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Mellone
authors.affiliation: Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Napoli, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Zuppa
authors.affiliation: Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Napoli, Italy. Electronic address: maria.costantini@szn.it.
authors.forename: Maria
authors.initials: M
authors.lastname: Costantini
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D020169:Caspases / Q000235:genetics / Q000378:metabolism*; D017377:Diatoms / Q000378:metabolism*; D004625:Embryo, Nonmammalian / Q000187:drug effects* / Q000201:enzymology; D054883:Oxylipins / Q000633:toxicity*; D047328:Paracentrotus / Q000187:drug effects* / Q000196:embryology / Q000201:enzymology; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D054883:Oxylipins; D014874:Water Pollutants, Chemical; D020169:Caspases
keywords: Apoptosis; Caspases; Diatoms; Sea urchin