title: Investigating the emerging role of comparative proteomics in the search for new biomarkers of metal contamination under varying abiotic conditions.
abstract: This study aims at investigating the potential use of comparative proteomics as a multi-marker approach of metal contamination, taking into account the potential confounding effect of water temperature. The major objective was to identify combinations of proteins specifically responding to a given metal, even if included in a metal mixture. The diagnostic approach was performed via the comparative analysis of protein expression on spot mapping provided by adult males of Gammarus pulex (Amphipoda, Crustacea) respectively exposed to arsenate (As), cadmium (Cd) or a binary mixture of these metals (AsCd) at three realistic temperatures (5, 10 and 15°C). Proteomic expression analysis was performed by Differential in-Gel Electrophoresis (2D-DiGE), and completed by an adapted inferential statistical approach. Combinations of under/over-expressed protein spots discriminated the metal identity. However, none of these spots discriminated both the individual metal effect (As or Cd) and its effect in metal mixture (AsCd) whatever the tested temperature. Some limits of the two-dimensional analysis of protein spot maps in G. pulex have been highlighted: (i) the presence of contaminating peptides and/or abundant "déja-vu" proteins which can mask the responses of other proteins of interest or (ii) the presence of post-translational modifications. An optimization of the experimental design (especially during the sample preparation) has been described for future investigations. This study has also highlighted (i) the importance of precisely identifying the protein spots of interest to avoid erroneous interpretations in terms of action mechanisms of chemicals and (ii) the importance of working under controlled laboratory conditions with a temperature close to 10°C. In such conditions, we have demonstrated a higher impact of As than Cd on the energetic metabolism of Gammarus. This As impact is reduced in AsCd mixture confirming the antagonistic interaction of this binary mixture previously observed on G. pulex mortality at 10°C.
authors.affiliation: Laboratoire Interdisciplinaire des Environnements Continentaux (LIEC), CNRS UMR 7360, Université de Lorraine - Metz, France. Electronic address: celine.vellinger@gmail.com.
authors.forename: Céline
authors.initials: C
authors.lastname: Vellinger
authors.affiliation: Laboratoire Interdisciplinaire des Environnements Continentaux (LIEC), CNRS UMR 7360, Université de Lorraine - Metz, France. Electronic address: benedicte.sohm@univ-lorraine.fr.
authors.forename: Bénédicte
authors.initials: B
authors.lastname: Sohm
authors.affiliation: Laboratoire Interdisciplinaire des Environnements Continentaux (LIEC), CNRS UMR 7360, Université de Lorraine - Metz, France. Electronic address: marc.parant@univ-lorraine.fr.
authors.forename: Marc
authors.initials: M
authors.lastname: Parant
authors.affiliation: Biogéosciences, CNRS UMR 6282, Université de Bourgogne - Dijon, France. Electronic address: Francoise.Immel@u-bourgogne.fr.
authors.forename: Françoise
authors.initials: F
authors.lastname: Immel
authors.affiliation: Laboratoire Interdisciplinaire des Environnements Continentaux (LIEC), CNRS UMR 7360, Université de Lorraine - Metz, France. Electronic address: philippe.usseglio-polatera@univ-lorraine.fr.
authors.forename: Philippe
authors.initials: P
authors.lastname: Usseglio-Polatera
mesh_terms: D033304:Amphipoda / Q000502:physiology*; D000818:Animals; D001149:Arsenates / Q000633:toxicity; D015415:Biomarkers / Q000378:metabolism; D002104:Cadmium / Q000633:toxicity; D008297:Male; D020543:Proteome / Q000378:metabolism*; D040901:Proteomics; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D001149:Arsenates; D015415:Biomarkers; D020543:Proteome; D014874:Water Pollutants, Chemical; D002104:Cadmium; C025657:arsenic acid
keywords: Arsenate; Cadmium; Ecotoxicological impact; Gammarus; Metal interaction; Temperature