Mechanisms underlying the protective effect of zinc and selenium against cadmium-induced oxidative stress in zebrafish Danio rerio

Abstract

The present study was designed to elucidate the protective effect mechanism of Zinc (Zn) and Selenium (Se) on cadmium (Cd)-induced oxidative stress in zebrafish. For this purpose we investigate the response of oxidative stress markers, metallothionein accumulation and gene expression in liver and ovary of female zebrafish exposed to 0,4 mg/l Cd in water and supplemented with Zn (5 mg kg(-1)) and/or Se (2 mg kg(-1)) for 21 days in their diet. Liver and ovary Cd uptake was evaluated after the exposure period. Cd exposure significantly inhibited the antioxidant enzyme activities termed as catalase (CAT), superoxide dismutase (SOD) and glutathione peroxydase (GPx) and caused a pronounced malondialdehyde (MDA) accumulation in both organs. Co-administration of Zn and Se reversed the Cd-induced toxicity in liver and ovary measured as MDA accumulation. Interestingly, gene expression patterns of Cat, CuZnSod and Gpx were up-regulated when related enzymatic activities were altered. Zebrafish metallothionein transcripts (zMt) significantly decreased in tissues of fish supplemented with Zn and/or Se when compared to Cd-exposed fish. Our data would suggest that Zn and Se protective mechanism against Cd-induced oxidative stress is more depending on the correction of the proteins biological activities rather than on the transcriptional level of related genes.

Metal detoxification and gene expression regulation after a Cd and Zn contamination: An experimental study on Danio rerio

“…In addition, the induction in the liver at T3 of the tap gene, coding for ABC transporters, was relevant of a metal excretion activity by tap ATPase-catalyzed pumping of Cd associated with cysteinrich polypeptides (Dassa and Bouige 2001). At T0, sod and sodmt activities were repressed in the gills and liver of fish exposed to Cd and Cd/Zn, as observed by Banni et al (2011). Since Cd is reported as altering the antioxidant defenses (Cuypers et al, 2010), these results suggest that the induction of genes involved in the oxidative stress (sod, sodmt) was possible in the liver only after the stop of the Cd contamination.…”

Molecular mechanism on cadmium-induced activity changes of catalase and superoxide dismutase

“…The modulation of the related genes and the direct interaction of Cd with the enzyme might account for the activity change of the enzyme [14,15]. However, the underlying molecular mechanisms have not been fully elucidated [16].…”

“…A number of studies have utilized zebrafish as a model system for studying Cd-induced oxidative stress both in vitro and in vivo [14,15,17] due to its capacity to sustain soft water [18], which is a basic requirement for testing biological response of Cd to avoid the interference with other cation [19]. The liver is the primary target organ for Cd accumulation; and it can be critically damaged by chronic Cd exposure from food [20].…”

Expression of the Laccase Gene from a White Rot Fungus in Pichia pastoris Can Enhance the Resistance of This Yeast to H 2 O 2 -Mediated Oxidative Stress by Stimulating the Glutathione-Based Antioxidative System

“…The activity of glutathione peroxidase (GPx) was measured using a GSH-Px detection kit (Nanjing Jiancheng Bioengineering Institute, Nanjing, China) according to the manufacturer's instructions; the kit was designed based on principles described by Hafeman et al and Banni et al (5,29). Glutathione peroxidase degraded H 2 O 2 in the presence of GSH, decreasing GSH levels.…”