title: Genotype-dependent gene expression profile of the antioxidant defense system (ADS) in the liver of a GH-transgenic zebrafish model.
abstract: The aim of this study was to evaluate the effects of growth hormone (GH) overexpression on the gene expression profile of multiple components of the antioxidant defense system (ADS) of different genotypes of a GH-transgenic zebrafish (Danio rerio) model. Several ADS-related genes were analyzed by semiquantitative reverse transcription-PCR in the liver of hemizygous (HE) and homozygous (HO) transgenic zebrafish. The results showed a significant reduction in the glutamate cysteine ligase catalytic subunit (GCLC) and the gene expression of two glutathione S-transferase (GST) isoforms and an increase in the glutathione reductase gene in the HO group compared to non-transgenic controls. The expression of the Cu, Zn-superoxide dismutase (SOD1) and catalase (CAT) genes was reduced in HO and HE groups, respectively. Among the ten genes analyzed, two were altered in HE transgenic zebrafish and five were altered in HO transgenic zebrafish. These findings indicate a genotype-dependent gene expression profile of the ADS-related genes in the liver of our GH-transgenic zebrafish model and are in agreement with the general effects of GH hypersecretion in the fish and mouse, which involves a reduction in the capability of the tissues to deal with oxidative stress situations. The GH-transgenic zebrafish model used here seems to be an interesting tool for analyzing the effect of different GH expression levels on physiological processes.
authors.affiliation: Instituto de Ciências Biológicas, Universidade Federal do Rio Grande (FURG), Avenida Itália, Km 8, Rio Grande, RS, 96201-900, Brazil.
authors.forename: Carlos E
authors.initials: CE
authors.lastname: da Rosa
authors.forename: Márcio A
authors.initials: MA
authors.lastname: Figueiredo
authors.forename: Carlos F C
authors.initials: CF
authors.lastname: Lanes
authors.forename: Daniela V
authors.initials: DV
authors.lastname: Almeida
authors.forename: Luis F
authors.initials: LF
authors.lastname: Marins
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified / Q000235:genetics / Q000378:metabolism*; D000975:Antioxidants / Q000378:metabolism*; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D005838:Genotype; D005721:Glutamate-Cysteine Ligase / Q000235:genetics / Q000378:metabolism; D005982:Glutathione Transferase / Q000235:genetics / Q000378:metabolism; D013006:Growth Hormone / Q000235:genetics*; D057898:Hemizygote; D006720:Homozygote; D008099:Liver / Q000201:enzymology*; D023421:Models, Animal; D018384:Oxidative Stress; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013482:Superoxide Dismutase / Q000235:genetics / Q000378:metabolism; D015027:Zebrafish / Q000235:genetics / Q000378:metabolism*
chemical_list: D000975:Antioxidants; D013006:Growth Hormone; D013482:Superoxide Dismutase; D005982:Glutathione Transferase; D005721:Glutamate-Cysteine Ligase