title: Transcriptional expression levels and biochemical markers of oxidative stress in Mytilus galloprovincialis exposed to nickel and heat stress.
abstract: The present study aims to evaluate transcriptional expression levels and biochemical markers of oxidative stress responses to nickel (Ni) exposure along with heat stress gradient in a mussel (Mytilus galloprovincialis). For this purpose, we investigated the response of oxidative stress markers, metallothionein accumulation and gene expression in digestive gland of mussels exposed to a sublethal concentration of Ni (2.5μM) along with a temperature gradient (18°C, 22°C, and 26°C) for 24h and 72h. Ni digestive gland uptake was evaluated after the exposure periods. Co-exposure to Ni and higher temperature (26°C) for 72h significantly decreased the antioxidant enzyme activities termed as catalase (CAT), superoxide dismutase (SOD) and glutathione-S-transferase (GST) and caused a pronounced increase of lipofuscin and neutral lipid (NL) accumulation. Ni-uptake was different with respect to the exposure periods and temperatures in Ni-exposed mussels. Sod, cat, gst, mt-10 and mt20 gene expression levels showed a substantial increased pattern in animals exposed for one day to heat stress compared to the control condition (18°C). The same pattern but with highest level was registered in animals co-exposed to Ni and temperatures within one day. Three days exposure to 18°C, 22°C and 26°C, resulted in a significant decrease in mRNA abundance of cat, gst and sod and a significant down-regulation of mts targets (22°C and 26°C). Our data provide new insights into the importance of the early protective response of oxidative stress related-gene expression and regulation in mussels challenging heat stress and sublethal Ni concentration.
authors.affiliation: Department of Environmental and Life Sciences, University of Piemonte Orientale Amedeo Avogadro, Via Bellini 25G, 15100 Alessandria, Italy; Laboratory of Biochemistry and Environmental Toxicology, ISA, Chott-Mariem, 4042 Sousse, Tunisia. Electronic address: m_banni@yahoo.fr.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Banni
authors.affiliation: Laboratory of Biochemistry and Environmental Toxicology, ISA, Chott-Mariem, 4042 Sousse, Tunisia.
authors.forename: Attig
authors.initials: A
authors.lastname: Hajer
authors.affiliation: Department of Environmental and Life Sciences, University of Piemonte Orientale Amedeo Avogadro, Via Bellini 25G, 15100 Alessandria, Italy.
authors.forename: Suzanna
authors.initials: S
authors.lastname: Sforzini
authors.affiliation: Department of Environmental and Life Sciences, University of Piemonte Orientale Amedeo Avogadro, Via Bellini 25G, 15100 Alessandria, Italy.
authors.forename: Caterina
authors.initials: C
authors.lastname: Oliveri
authors.affiliation: Laboratory of Biochemistry and Environmental Toxicology, ISA, Chott-Mariem, 4042 Sousse, Tunisia.
authors.forename: Hamadi
authors.initials: H
authors.lastname: Boussetta
authors.affiliation: Department of Environmental and Life Sciences, University of Piemonte Orientale Amedeo Avogadro, Via Bellini 25G, 15100 Alessandria, Italy.
authors.forename: Aldo
authors.initials: A
authors.lastname: Viarengo
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D005260:Female; D005786:Gene Expression Regulation; D018869:Heat-Shock Response / Q000187:drug effects / Q000502:physiology*; D006358:Hot Temperature / Q000009:adverse effects*; D049878:Mytilus; D009532:Nickel / Q000633:toxicity*; D018384:Oxidative Stress / Q000187:drug effects / Q000502:physiology*; D014158:Transcription, Genetic / Q000187:drug effects / Q000502:physiology*
chemical_list: D015415:Biomarkers; D009532:Nickel
keywords: Gene expression; Heat stress; Mytilus galloprovincialis; Nickel; Oxidative stress