Transcript Analysis of the Selenoproteome Indicates That Dietary Selenium Requirements of Rats Based on Selenium-Regulated Selenoprotein mRNA Levels Are Uniformly Less Than Those Based on Glutathione Peroxidase Activity
- 1 February 2009
- journal article
- research article
- Published by Elsevier BV in Journal of Nutrition
- Vol. 139 (2), 199-206
- https://doi.org/10.3945/jn.108.098624
Abstract
Dietary selenium (Se) requirements in rats have been based largely upon glutathione peroxidase-1 (Gpx1) enzyme activity and Gpx1 mRNA levels can also be used to determine Se requirements. The identification of the complete selenoprotein proteome suggests that we might identify additional useful molecular biomarkers for assessment of Se status. To characterize Se regulation of the entire rat selenoproteome, weanling male rats were fed a Se-deficient diet (μg Se/g) supplemented with graded levels of Se (0–0.8 μg/g diet) for 28 d, Se status was determined by tissue Se concentration and selenoenzyme activity, and selenoprotein mRNA abundance in liver, kidney, and muscle was determined by quantitative real-time-PCR. Tissue Se and selenoenzyme biomarkers indicated that minimal Se requirements were ≤0.1 μg Se/g diet for most biomarkers. Liver Gpx1 mRNA also decreased to μg/g diet. Five selenoprotein mRNA in liver, 4 in kidney, and 2 in muscle decreased to μg/g diet; the majority of selenoprotein mRNA in each tissue were not significantly regulated by Se status, and 1 selenoprotein, selenophosphate synthetase-2, was upregulated in Se-deficient kidney. Plateau breakpoints for all regulated selenoprotein mRNA were very similar, suggesting that 1 underlying mechanism is in play in Se regulation of selenoprotein mRNA. Lastly, we did not find any selenoprotein mRNA that could be used as biomarkers for super-nutritional/anticarcinogenic levels (up to 0.8 μg Se/g diet) of Se.Keywords
This publication has 49 references indexed in Scilit:
- Selenium status highly regulates selenoprotein mRNA levels for only a subset of the selenoproteins in the selenoproteomeBioscience Reports, 2009
- Longitudinal selenium status in healthy British adults: assessment using biochemical and molecular biomarkersBritish Journal of Nutrition, 2008
- The selenoproteome exhibits widely varying, tissue-specific dependence on selenoprotein P for selenium supplyNucleic Acids Research, 2007
- Selenophosphate synthetase 2 is essential for selenoprotein biosynthesisBiochemical Journal, 2007
- A new mathematical model for relative quantification in real-time RT-PCRNucleic Acids Research, 2001
- Dietary selenium regulation of glutathione peroxidase mRNA and other selenium-dependent parameters in male ratsThe Journal of Nutritional Biochemistry, 1997
- Effect of selenium status on mRNA levels for glutathione peroxidase in rat liverBiochemical and Biophysical Research Communications, 1988
- Glutathione peroxidase activity in rat lens and other tissues in relation to dietary selenium intakeExperimental Eye Research, 1974
- SELENIUM AS AN INTEGRAL PART OF FACTOR 3 AGAINST DIETARY NECROTIC LIVER DEGENERATIONJournal of the American Chemical Society, 1957