Living organisms face an array of various environmental stressors that vary in space and time. For scientists and regulators alike, it is a great challenge to assess these complex risks for human health and the environment. In this laboratory study, we exposed continuously Paracentrotus lividus embryos to a double stress, i.e., cadmium (Cd) from fertilization and UVB at cleavage (Cd/UVB-embryos) and analyzed the effects on signal transduction pathways and stress genes expression. By microscopical inspection at 72 h of development, we evaluated embryo morphogenesis and assessed mesoderm differentiation using tissue-specific markers by immunofluorescence. By Western blot, we analyzed p38MAPK, ERK1/2, and JNK activation. The mRNA profiles of Pl-MT, Pl-14-3-3epsilon, and Pl-jun genes were analyzed 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 caused skeleton malformations in 76% of pluteus embryos, mainly affecting the normal branching of skeletal roads. In Cd/UVB-embryos 1 h after UVB exposure, p38MAPK was activated and 24 h after UVB exposure Pl-MT, Pl-14.3.3epsilon, and Pl-jun genes were over-expressed. Pl-MT and Pl-14.3.3epsilon mRNAs were also misexpressed as they were localized not only in the intestine, as observed in wild-type embryos, but also in other territories. On the contrary, Pl-jun mRNA remained localized in the skeletogenic cells, despite their displacement. 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 genes over-expression seem linked to a protective role against the stress response induced by Cd/UVB.
p38 MAPK activation and stress genes over-expression in sea urchin embryos co-exposed to cadmium and UVB radiation
Rosa Bonaventura;Roberta Russo;Francesca Zito;Valeria Matranga
2015
Abstract
Living organisms face an array of various environmental stressors that vary in space and time. For scientists and regulators alike, it is a great challenge to assess these complex risks for human health and the environment. In this laboratory study, we exposed continuously Paracentrotus lividus embryos to a double stress, i.e., cadmium (Cd) from fertilization and UVB at cleavage (Cd/UVB-embryos) and analyzed the effects on signal transduction pathways and stress genes expression. By microscopical inspection at 72 h of development, we evaluated embryo morphogenesis and assessed mesoderm differentiation using tissue-specific markers by immunofluorescence. By Western blot, we analyzed p38MAPK, ERK1/2, and JNK activation. The mRNA profiles of Pl-MT, Pl-14-3-3epsilon, and Pl-jun genes were analyzed 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 caused skeleton malformations in 76% of pluteus embryos, mainly affecting the normal branching of skeletal roads. In Cd/UVB-embryos 1 h after UVB exposure, p38MAPK was activated and 24 h after UVB exposure Pl-MT, Pl-14.3.3epsilon, and Pl-jun genes were over-expressed. Pl-MT and Pl-14.3.3epsilon mRNAs were also misexpressed as they were localized not only in the intestine, as observed in wild-type embryos, but also in other territories. On the contrary, Pl-jun mRNA remained localized in the skeletogenic cells, despite their displacement. 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 genes over-expression seem linked to a protective role against the stress response induced by Cd/UVB.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
