title: DNA adduct formation and induction of detoxification mechanisms in Dreissena polymorpha exposed to nitro-PAHs.
abstract: Derived polycyclic aromatic hydrocarbons (PAHs) such as nitro-PAHs are present in the environment and are known to be much more toxic than PAHs compounds. However, very few studies have analysed their effects on the aquatic environment and none have investigated the freshwater environment. In the present study, we determined whether 1-nitropyrene (1-NP), a model of nitro-PAHs, can induce DNA adducts in gills and digestive glands of the freshwater mussel Dreissena polymorpha. Two concentrations of 1-NP (50 and 500 μM) were tested. In addition, in order to understand the metabolic pathways involved in 1-NP genotoxicity, mRNA expression of genes implicated in biotransformation mechanisms was assessed by quantitative reverse transcription-PCR. Results showed the presence of DNA adducts in both gills and digestive glands, with highest levels obtained after 5 days of exposure to 500 μM. Metallothionein mRNA levels were enhanced in digestive glands exposed to 50 μM. Surprisingly, at the higher concentration (500 μM), aryl hydrocarbon receptor and HSP70 genes were only up-regulated in digestive glands while PgP mRNA levels were increased in both tissues. Results suggested a cytotoxic and genotoxic effect of 1-NP. Mussels seemed to be able to partially detoxify this compound, in view of the low amount of DNA adducts observed after 5 days exposure to 50 μM. For the first time, 1-NP biotransformation and detoxification systems have been characterised in D. polymorpha.
authors.affiliation: IRSTEA, Unité de Recherche Hydrosystèmes et Bioprocédés, 1 rue Pierre-Gilles de Gennes, CS10030, Antony 92761, France and Present address: Université de Nantes, MMS, EA2160, Faculté de Pharmacie, 1 rue G. Veil, BP 53508, 44035 Nantes Cedex 1, France and Université Catholique de l'Ouest, Pôle recherche Département Sciences, 3 place André Leroy, BP10808, 49008 Angers Cedex 01, France. amelie.chatel@uco.fr.
authors.forename: Amélie
authors.initials: A
authors.lastname: Châtel
authors.affiliation: Université de Toulouse, INPT/ENSAT, Laboratoire de Génie Chimie, UMR-CNRS 5503, Département Bioprocédés et systèmes microbiens, 1 avenue agrobiopôle, Auzeville-Tolosane 31320, France.
authors.forename: Virginie
authors.initials: V
authors.lastname: Faucet-Marquis
authors.affiliation: Université de Toulouse, INPT/ENSAT, Laboratoire de Génie Chimie, UMR-CNRS 5503, Département Bioprocédés et systèmes microbiens, 1 avenue agrobiopôle, Auzeville-Tolosane 31320, France.
authors.forename: Annie
authors.initials: A
authors.lastname: Pfohl-Leszkowicz
authors.affiliation: IRSTEA, Unité de Recherche Hydrosystèmes et Bioprocédés, 1 rue Pierre-Gilles de Gennes, CS10030, Antony 92761, France and.
authors.forename: Catherine
authors.initials: C
authors.lastname: Gourlay-Francé
authors.affiliation: IRSTEA, Unité de Recherche Hydrosystèmes et Bioprocédés, 1 rue Pierre-Gilles de Gennes, CS10030, Antony 92761, France and Present address: IFREMER, Laboratoire de microbioologie-LNR, centre de Nantes, BP 21105, 44311 Nantes Cedex 03, France.
authors.forename: Françoise
authors.initials: F
authors.lastname: Vincent-Hubert
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D018736:DNA Adducts / Q000187:drug effects / Q000378:metabolism*; D004064:Digestive System / Q000187:drug effects / Q000378:metabolism; D049875:Dreissena / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000187:drug effects; D005880:Gills / Q000187:drug effects / Q000378:metabolism; D008658:Inactivation, Metabolic / Q000235:genetics; D011084:Polycyclic Aromatic Hydrocarbons / Q000633:toxicity*; D011721:Pyrenes / Q000633:toxicity*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism
chemical_list: D015415:Biomarkers; D018736:DNA Adducts; D011084:Polycyclic Aromatic Hydrocarbons; D011721:Pyrenes; D012333:RNA, Messenger; C032668:1-nitropyrene