title: Combined Effects of Cadmium and UVB Radiation on Sea Urchin Embryos: Skeleton Impairment Parallels p38 MAPK Activation and Stress Genes Overexpression.
abstract: Human and natural activities release many pollutants in the marine environment. The mixture of pollutants can affect many organisms concurrently. We used Paracentrotus lividus as a model to analyze the effects on signal transduction pathways and stress gene expression in embryos exposed continuously to double stress, i.e., cadmium (Cd) from fertilization and UVB at cleavage (Cd/UVB-embryos). By microscopical inspection, we evaluated embryonic morphology after 72 h of development. Tissue-specific markers were used to assess mesoderm differentiation by immunofluorescence. We analyzed p38MAPK, ERK1/2, and JNK activation by Western blot and mRNA profiles of Pl-MT, Pl-14-3-3epsilon, and Pl-jun genes by real-time quantitative polymerase chain reaction (qPCR) and the localization of their transcripts by whole mount in situ hybridization (WMISH). We found that the Cd/UVB combined exposure induced morphological malformations in 76% of pluteus embryos, mainly affecting the development of the skeleton, including the normal branching of skeletal roads. In Cd/UVB-embryos, p38MAPK was activated 1 h after UVB exposure and a remarkable overexpression of the Pl-MT, Pl-14.3.3epsilon, and Pl-jun genes 24 h after UVB exposure. Pl-MT and Pl-14.3.3epsilon mRNAs were misexpressed as they were localized in a position different from that observed in wild-type embryos, i.e., the intestine. On the contrary, Pl-jun mRNA has remained localized in the skeletogenic cells despite their displacement in exposed embryos. In conclusion, Cd/UVB exposure affected skeletal patterning producing alternative morphologies in which p38MAPK activation and Pl-MT, Pl-14.3.3epsilon, and Pl-jun gene overexpression seem linked to a protective role against the stress response induced by Cd/UVB.
authors: Consiglio Nazionale delle Ricerche, Istituto di Biomedicina e Immunologia Molecolare "Alberto Monroy", Via Ugo La Malfa 153, 90146 Palermo, Italy.
authors: Rosa
authors: R
authors: Bonaventura
authors: Consiglio Nazionale delle Ricerche, Istituto di Biomedicina e Immunologia Molecolare "Alberto Monroy", Via Ugo La Malfa 153, 90146 Palermo, Italy.
authors: Roberta
authors: R
authors: Russo
authors: Consiglio Nazionale delle Ricerche, Istituto di Biomedicina e Immunologia Molecolare "Alberto Monroy", Via Ugo La Malfa 153, 90146 Palermo, Italy.
authors: Francesca
authors: F
authors: Zito
authors: Consiglio Nazionale delle Ricerche, Istituto di Biomedicina e Immunologia Molecolare "Alberto Monroy", Via Ugo La Malfa 153, 90146 Palermo, Italy.
authors: Valeria
authors: V
authors: Matranga
mesh_terms: D000818:Animals; D002104:Cadmium / Q000633:toxicity*; D004625:Embryo, Nonmammalian / Q000002:abnormalities* / Q000187:drug effects / Q000196:embryology / Q000528:radiation effects*; D004789:Enzyme Activation / Q000187:drug effects / Q000528:radiation effects; D047328:Paracentrotus / Q000187:drug effects / Q000196:embryology* / Q000235:genetics / Q000528:radiation effects*; D012333:RNA, Messenger / Q000235:genetics; D012863:Skeleton / Q000002:abnormalities / Q000187:drug effects / Q000196:embryology / Q000528:radiation effects; D015854:Up-Regulation / Q000187:drug effects; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism
chemical_list: D012333:RNA, Messenger; D002104:Cadmium; D048051:p38 Mitogen-Activated Protein Kinases