Department of Marine Biotechnology, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Napoli, Italy.
Department of Biology, University of Naples Federico II, Complesso Universitario di Monte Sant'Angelo, Via Cinthia 21, 80126 Napoli, Italy.
Int J Mol Sci. 2020 Jan 22;21(3):719. doi: 10.3390/ijms21030719.
Oxylipins are diatom-derived secondary metabolites, deriving from the oxidation of polyunsatured fatty acids that are released from cell membranes after cell damage or senescence of these single-celled algae. Previous results revealed harmful toxic effects of polyunsaturated aldehydes (PUAs) and hydroxyacids (HEPEs) on sea urchin embryonic development by testing individual compounds and mixtures of the same chemical group. Here, we investigated the combined effects of these compounds on sea urchin development at the morphological and molecular level for the first time. Our results demonstrated that oxylipin mixtures had stronger effects on sea urchin embryos compared with individual compounds, confirming that PUAs induce malformations and HEPEs cause developmental delay. This harmful effect was also confirmed by molecular analysis. Twelve new genes, involved in stress response and embryonic developmental processes, were isolated from the sea urchin ; these genes were found to be functionally interconnected with 11 genes already identified as a stress response of embryos to single oxylipins. The expression levels of most of the analyzed genes targeted by oxylipin mixtures were involved in stress, skeletogenesis, development/differentiation, and detoxification processes. This work has important ecological implications, considering that PUAs and HEPEs represent the most abundant oxylipins in bloom-forming diatoms, opening new perspectives in understanding the molecular pathways activated by sea urchins exposed to diatom oxylipins.
氧化脂类是硅藻衍生的次生代谢物，来源于多不饱和脂肪酸的氧化，这些脂肪酸是在这些单细胞藻类的细胞膜损伤或衰老后从细胞膜中释放出来的。以前的研究结果表明，通过测试单一化合物和同化学基团的混合物，多不饱和醛（PUAs）和羟基酸（HEPEs）对海胆胚胎发育有有害的毒性作用。在这里，我们首次在形态和分子水平上研究了这些化合物对海胆发育的综合影响。我们的结果表明，氧化脂类混合物对海胆胚胎的影响比单一化合物更强，证实了 PUAs 诱导畸形，HEPEs 导致发育迟缓。分子分析也证实了这种有害影响。从海胆中分离出 12 个新基因，这些基因参与应激反应和胚胎发育过程；这些基因与已经确定的 11 个基因在应激反应中具有功能上的相互联系，这些基因与胚胎对单一氧化脂类的应激反应有关。大多数分析基因的表达水平都与应激、骨骼生成、发育/分化和解毒过程有关。考虑到 PUA 和 HEPEs 是形成藻华的硅藻中最丰富的氧化脂类，这项工作具有重要的生态意义，为理解暴露于硅藻氧化脂类的海胆激活的分子途径开辟了新的前景。
