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Comparative regulation of novel porcine selenoprotein gene expression in endocrine tissues and liver by dietary selenium
Author(s) -
Lei X G,
Zhou J C,
Zhao H,
Li J G,
Wang K N,
Xia X,
Zhang Y J,
Liu Y,
Zhao Y
Publication year - 2009
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.23.1_supplement.346.5
Subject(s) - selenoprotein , selenoprotein p , endocrinology , gpx1 , medicine , biology , gene expression , thyroid , selenium , endocrine system , messenger rna , gene , glutathione peroxidase , oxidative stress , hormone , chemistry , biochemistry , superoxide dismutase , organic chemistry
Expression and function of selenoproteins in endocrine tissues remain unclear. We conducted 2 experiments: 1) to clone 5 novel selenoprotein genes from pig tissues, and 2) to compare effects of dietary Se on mRNA levels of 12 selenoproteins, activities of 4 antioxidant enzymes, and Se concentrations in testis, thyroid, and pituitary with those in liver of pigs. In Exp. 1, porcine Gpx2, Sephs2, Sep15, Sepn1 and Sepp1 were cloned and demonstrated 84 to 94% of open reading frame homology to human genes. In Exp. 2, 30 weanling male pigs were fed a Se‐deficient (0.02 mg/kg) diet supplemented with 0, 0.3 or 3.0 mg Se/kg as Se‐enriched yeast (Angel Yeast, Hubei, China) for 8 wks. While dietary Se resulted in dose‐dependent increases in Se concentrations and GPX activities in all 4 tissues, its effects on gene expression of the 12 selenoproteins fell into 3 categories. Dietary Se exhibited no significant effect on the mRNA levels of any gene in thyroid and pituitary or 7 genes in any tissue. Testis mRNA levels of Txnrd1 and Sep15 were decreased by supplementing 3.0 mg of Se/kg compared with the 0.3 mg Se/kg group. In conclusion, dietary Se deficiency and supranutrition produced similar responses of Se concentrations and GPX activities in endocrine tissues and liver, but exerted essentially no impact on mRNA abundances of all 12 selenoprotein genes in thyroid and pituitary (Chinese Natural Science Foundation Projects 30628019 & 30700585).