| Title | Genotoxic damage of benzo[a]pyrene in cultured sea bream (Sparus aurata L.) hepatocytes: Harmful effects of chronic exposure |
| Abstract | The large majority of studies on the genotoxic hazard of PAHs polluted water widely applied the ENA assay as versatile tool in large number of wild and farmed aquatic species. Nuclear abnormalities are commonly considered to be a direct consequence of genotoxic lesions in DNA macromolecule, and such evaluation might be helpful in identifying the genotoxic damage induced by the most harmful PAHs such as B[a]P. Regarding at the fish species subjected to aquaculture, most of the toxicological data come from wild fish and mainly focus on freshwater fish, but very little is known for other marine major aqua-cultured species. The gilthead sea bream (Sparus aurata L.) is the most economically important sparid species cultured along the Mediterranean costs, and it has been proved a very sensitive species to acute B [a]P exposure. However, further investigation is needed on several other types of genotoxic assessments, especially for chronic effects. This work was totally based on an in vitro model for chronic toxicity, using long-term S. aurata hepatocytes in primary culture, continuously exposed to low levels of BaP, over a prolonged period of time, to provide evidences for latent toxicity response. We aimed to investigate the kind of nuclear damage in gilthead sea bream hepatocytes continuously exposed to B[a]P sublethal doses. Cells were exposed to several B[a]P concentrations (10 mu g/mL, 1 mu g/mL, 1 mu g/mL, 1 mu g/mL) for two exposure times (24 and 72 h), and then tested both for apoptosis induction and for nuclear abnormalities by immunofluorescence analysis. The presence of severe nuclear damage, revealed cells progressing towards abnormal genotypes, due to a series of aberrant mitosis followed by unequal distribution of chromosomal content. The nuclear atypia (NA) more frequently observed were: a) micronuclei (MN); b) nuclear buds or blebs (NBUDs); c) notched nuclei; d) lobed nuclei; e) nuclei with nucleoplasmic bridge (NPBs); f) nuclei squashed, with a residual nuclear membrane; g) open nuclei, with membrane tape unrolled; and h) apoptotic bodies. Our results showed at medium-low doses a sustained genotoxic response, whose potency increased with the exposure time, becoming apparent as apoptosis induction, both by cell surface and nuclear changes. At the lowest doses, the longer was B[a]P exposure, greater was the involvement on masses of replicating cells, establishing the connection between the escape from apoptosis and the selection of tumoral cell evolution. In view of these results, there is no evidence of a threshold dose below which B[a]P was found not to be genotoxic in sea bream cultured hepatocytes. (c) 2014 Elsevier Ltd. All rights reserved. |
| Source | Marine environmental research 100, pp. 74–85 |
| Keywords | PAHNuclear abnormalitiesSparus aurataApoptosis |
| Journal | Marine environmental research |
| Editor | Applied Science Publishers,, Barking, Regno Unito |
| Year | 2014 |
| Type | Articolo in rivista |
| DOI | 10.1016/j.marenvres.2014.04.003 |
| Authors | Pastore, Anna Selene; Santacroce, Maria Pia; Narracci, Marcella; Cavallo, Rosa Anna; Acquaviva, Maria Immacolata; Casalino, Elisabetta; Colamonaco, Michele; Crescenzo, Giuseppe |
| Text | 319220 2014 10.1016/j.marenvres.2014.04.003 ISI Web of Science WOS 000342245100011 PAH Nuclear abnormalities Sparus aurata Apoptosis Genotoxic damage of benzo a pyrene in cultured sea bream Sparus aurata L. hepatocytes Harmful effects of chronic exposure Pastore, Anna Selene; Santacroce, Maria Pia; Narracci, Marcella; Cavallo, Rosa Anna; Acquaviva, Maria Immacolata; Casalino, Elisabetta; Colamonaco, Michele; Crescenzo, Giuseppe University of Bari; Consiglio Nazionale delle Ricerche CNR ; University of Bari; University of Bari The large majority of studies on the genotoxic hazard of PAHs polluted water widely applied the ENA assay as versatile tool in large number of wild and farmed aquatic species. Nuclear abnormalities are commonly considered to be a direct consequence of genotoxic lesions in DNA macromolecule, and such evaluation might be helpful in identifying the genotoxic damage induced by the most harmful PAHs such as B a P. Regarding at the fish species subjected to aquaculture, most of the toxicological data come from wild fish and mainly focus on freshwater fish, but very little is known for other marine major aqua cultured species. The gilthead sea bream Sparus aurata L. is the most economically important sparid species cultured along the Mediterranean costs, and it has been proved a very sensitive species to acute B a P exposure. However, further investigation is needed on several other types of genotoxic assessments, especially for chronic effects. This work was totally based on an in vitro model for chronic toxicity, using long term S. aurata hepatocytes in primary culture, continuously exposed to low levels of BaP, over a prolonged period of time, to provide evidences for latent toxicity response. We aimed to investigate the kind of nuclear damage in gilthead sea bream hepatocytes continuously exposed to B a P sublethal doses. Cells were exposed to several B a P concentrations 10 mu g/mL, 1 mu g/mL, 1 mu g/mL, 1 mu g/mL for two exposure times 24 and 72 h , and then tested both for apoptosis induction and for nuclear abnormalities by immunofluorescence analysis. The presence of severe nuclear damage, revealed cells progressing towards abnormal genotypes, due to a series of aberrant mitosis followed by unequal distribution of chromosomal content. The nuclear atypia NA more frequently observed were a micronuclei MN ; b nuclear buds or blebs NBUDs ; c notched nuclei; d lobed nuclei; e nuclei with nucleoplasmic bridge NPBs ; f nuclei squashed, with a residual nuclear membrane; g open nuclei, with membrane tape unrolled; and h apoptotic bodies. Our results showed at medium low doses a sustained genotoxic response, whose potency increased with the exposure time, becoming apparent as apoptosis induction, both by cell surface and nuclear changes. At the lowest doses, the longer was B a P exposure, greater was the involvement on masses of replicating cells, establishing the connection between the escape from apoptosis and the selection of tumoral cell evolution. In view of these results, there is no evidence of a threshold dose below which B a P was found not to be genotoxic in sea bream cultured hepatocytes. c 2014 Elsevier Ltd. All rights reserved. 100 Published version Articolo in rivista Applied Science Publishers, 0141 1136 Marine environmental research Marine environmental research Mar. environ. res. Marine environmental research. Journal of marine environmental research mariaimmacolata.acquaviva ACQUAVIVA MARIA IMMACOLATA marcella.narracci NARRACCI MARCELLA rosaanna.cavallo CAVALLO ROSA ANNA |
