QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Online Supplemental Material All Versions of this Article: 139/2/199    most recent jn.108.098624v1 Purchase Article View Shopping Cart Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Barnes, K. M. Articles by Sunde, R. A. Search for Related Content PubMed PubMed Citation Articles by Barnes, K. M. Articles by Sunde, R. A.

---

Biochemical, Molecular, and Genetic Mechanisms

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^1–3,

Department of Nutritional Sciences, University of Wisconsin, Madison, WI 53706

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 (<0.01 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 <10% of Se-adequate levels, with a minimum Se requirement at 0.07 µg/g diet. Five selenoprotein mRNA in liver, 4 in kidney, and 2 in muscle decreased to <41% of Se-adequate levels, all with minimum Se requirements at 0.07 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.

^* To whom correspondence should be addressed: E-mail: sunde{at}nutrisci.wisc.edu.

Manuscript received 21 August 2008. Initial review completed 8 September 2008. Revision accepted 7 November 2008.

Published online 23 December 2008.

This article has been cited by other articles:

				R. A. Sunde, K. M. Thompson, J. K. Evenson, and B. M. Thompson Blood Glutathione Peroxidase-1 mRNA Levels Can Be Used as Molecular Biomarkers to Determine Dietary Selenium Requirements in Rats Experimental Biology and Medicine, November 1, 2009; 234(11): 1271 - 1279. [Abstract] [Full Text] [PDF]

				S. C. Schriever, K. M. Barnes, J. K. Evenson, A. M. Raines, and R. A. Sunde Selenium Requirements Are Higher for Glutathione Peroxidase-1 mRNA than Gpx1 Activity in Rat Testis Experimental Biology and Medicine, May 1, 2009; 234(5): 513 - 521. [Abstract] [Full Text] [PDF]