Metallothionein levels in Algerian mice (Mus spretus) exposed to elemental pollution: An ecophysiological approach

Centro de Biologia Ambiental, Departamento de Biologia Animal, Faculdade de Ciências da Universidade de Lisboa, Edificio C2, 1749-016 Lisboa, Portugal. <>
Chemosphere (Impact Factor: 3.34). 05/2008; 71(7):1340-7. DOI: 10.1016/j.chemosphere.2007.11.024
Source: PubMed


The potential use of metallothioneins (MTs) as biomarkers of trace metal contamination was evaluated for the first time in the Algerian mouse (Mus spretus). Mice were collected seasonally in an abandoned mining area (Aljustrel) and in a reference area, both located in southern Portugal. MT levels were quantified in liver and kidney by differential pulse polarography and hepatic elemental concentrations (Mn, Fe, Cu, Zn, Se) were determined by particle-induced X-ray emission. Hepatic iron and selenium concentrations were elevated in mice from Aljustrel mine when compared to reference animals. MTs levels were averagely higher in mice from Aljustrel than those originated from the reference area. A season-dependent significant effect was found on the hepatic and renal MT concentrations, characterized by higher levels in winter and lower in autumn. In contaminated mice positive relationship between liver elemental contents (Cu in autumn and Fe in winter) and MTs were found. The seasonal variation of MT suggests that probably physiological and environmental factors could influence hepatic and renal MT induction. Results seem to imply that some environmental disturbance occur in the vicinity of the Aljustrel mine. Therefore, for the management purposes MT levels should be followed in liver of M. spretus, especially in winter. Furthermore, other physiological factors that could influence MT expression and turnover in Algerian mouse should also be monitored.

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Available from: Ana Maria Viegas-Crespo, Oct 07, 2015
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    • "The relationships between exposure to metals and MT levels have been well studied in the laboratory for certain mammal species, mainly rodents used as animal models (mouse and rat) and also for a wild small mammal, the bank vole Myodes (ex-Clethrionomys ) glareolus (Wlostowski, 1992b; Wlostowski and Krasowska, 1999; Klaassen et al., 2009). However, few field studies investigated the relationships between metal accumulation and MT levels in wild terrestrial vertebrates except in recent biomonitoring studies using MTs as exposure biomarkers (Rogival et al., 2007a; Marques et al., 2008; Vanparys et al., 2008). For small mammals, some studies showed that MT levels were more elevated in individuals coming from contaminated areas (Damek-Poprawa, 2002; Rogival et al., 2007a; Swiergosz-Kowalewska et al., 2007; Marques et al., 2008). "
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    ABSTRACT: We investigated how host factors (species, age, gender) modulated Cd, Pb, Zn, and Cu concentrations, metallothionein levels (MTs) and their relationships in 7 sympatric small mammal species along a pollution gradient. Cd concentrations in liver and kidneys increased with age in all species. Age effect on other metals and MTs differs among species. Gender did not influence metal and MT levels except in the bank vole. Three patterns linking internal metal concentrations and MTs were observed along the gradient: a low metal accumulation with a (i) high (wood mouse) or (ii) low (bank vole) level of MTs accompanied by a slight or no increase of MTs with Cd accumulation; (iii) an elevated metal accumulation with a sharp increase of MTs (common and pygmy shrews). In risk assessment and biomonitoring perspectives, we conclude that measurements of MTs and metals might be associated because they cannot be interpreted properly when considered separately.
    Environmental Pollution 11/2009; 158(3):827-40. DOI:10.1016/j.envpol.2009.09.027 · 4.14 Impact Factor
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    • "Among different invertebrates exposed to PCBs and PAHs, induction of GST and GPx activities were observed (Förlin et al. 1996; Machala et al. 1998; Martin-Diaz et al. 2008; Martín- Díaz et al. 2007). MT were used as biomarkers of heavy metals exposure on several organisms including vertebrates and invertebrates: mice Mus spretus (Marques et al. 2008), fish Scatophagus argus (Nikpour et al. 2008), crab Carcinus maenas (Pedersen et al. 1997), mussel Mytilus edulis (Geffard et al. 2005), and clam Ruditapes decussates (Hamza-Chaffai et al. 1999). Bivalve molluscs are appropriate sentinel species to study the quality of the aquatic environment. "
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    ABSTRACT: The cDNA sequences encoding manganese superoxide dismutase (Mn-SOD) and catalase (CAT) were isolated in the freshwater bivalve Unio tumidus by reverse-transcription polymerase chain reaction (RT-PCR) using degenerate primers. Quantitative real-time PCR approach was used to evaluate the mRNA expression patterns of SOD, CAT, selenium-dependent glutathione peroxidase (Se-GPx), pi class glutathione S-transferase (pi-GST) and metallothionein (MT), in the digestive gland of Unio tumidus transplanted from a control site to four stations in the Moselle River (M1-M4), for periods of 8 and 21 days. These sites were chosen upstream and downstream of populated areas. Chemical analysis performed on sediments from the Moselle river sites did not show high levels of pollutants. Decrease of SOD, CAT, Se-GPx and MT mRNA levels were observed at M3 site after a 21-day exposure compared to control site. These results suggest inefficiency of antioxidant systems affected by cytotoxic mechanisms and confirm an environmental perturbation. Organisms transplanted at M4 site showed a strong increase of biomarkers transcription levels after 21 days of exposure. These inductions could correspond to an adaptive response to an altered environment. Our results showed that biological approaches using multibiomarkers appear as essential tools complementary to measurement of contaminants, to detect environmental degradations.
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    ABSTRACT: Glutathione S-transferases (GSTs) are pivotal phase-II enzymes for detoxification of xenobiotics. Pi-class GSTs play key roles in determining cancer susceptibility. The laboratory mouse Mus musculus (Mm) has two GST-Pi-encoding genes; while MmGstp1 is the counterpart of the unique human and rat Pi-class GST gene, the function of MmGstp2 remains unclear because its expression is almost undetectable in liver and its product lacks activity against typical GST/GST-Pi substrates. Mus spretus (Ms) is an aboriginal mouse species of great interest as a bio-indicator in environmental pollution studies and a reservoir of novel allelic variants and phenotypes. Using absolute real-time RT-PCR, we demonstrate significant differences in the hepatic levels of GST-Pi-encoding mRNAs between both mouse species. Particularly, we found that the Gstp2 gene of M. spretus, unlike its M. musculus counterpart, attains relatively high steady-state level of expression (∼30molecules/pg of total liver RNA in mice dwelling in a non-polluted area). To test whether the interspecies difference in Gstp2 mRNA levels is due, at least in part, to evolutionary divergence in the promoter regions, we (i) sequenced the 5'-flanking regulatory regions of the two Gstp2 genes; (ii) used bioinformatics tools to identify differences in TF binding sites (TFBSs) and cis-regulatory modules; and (iii) extended the in silico results to a cell-based functional assay. We observed high sequence divergence (2.8%) and differences in TFBSs (32.6%) between the two Gstp2 promoters. We also show that constructs harbouring promoter fragments with species-specific cis-regulatory motifs displayed differential luciferase reporter activity, suggesting that these promoter sequence variations may determine, at least in part, the strong difference in Gstp2 mRNA levels between M. musculus and M. spretus. Additionally, the comparative analysis of the coding sequences predicts that the MsGstp2 product may be an active Pi-class GST because of a Pro(12) to Arg(12) substitution. Interestingly, free-living M. spretus mice dwelling at an industrial settlement displayed significantly higher amounts of transcripts for both GST-P1 and GST-P2 than those from a non-polluted area, suggesting that. M. spretus may optimise the response to pollution by co-evolving the expression levels of the two Pi-class GST genes. Overall, our data suggest that MsGstp2 may be one of the genes contributing to the natural resistance of M. spretus, facilitating its adaptation in a wild environment. Further insights into the functional roles of mouse Pi-class GSTs should be gained from the data reported in this work.
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