Effect of age on sexually dimorphic selenoprotein expression in mice

Biol Chem. 2007 Oct;388(10):1035-41. doi: 10.1515/BC.2007.128.

Abstract

Clinical data suggest that selenium (Se) supplementation decreases disease predisposition and severity and accelerates recovery in a variety of pathologies. Pre-supplementation Se levels and sex represent important determinants of these Se-dependent health effects. Accordingly, we previously reported on sexually dimorphic expression patterns of Se-dependent glutathione peroxidase 1, type I deiodinase, and selenoprotein P in young mice. In the present study we investigated whether these differences vary with age. The strong sexual dimorphic expression of hepatic type I deiodinase that was observed in young mice vanished both at the mRNA and enzyme activity level by 1 year of age. In contrast, the strong sex-specific differences in renal type I deiodinase mRNA expression were sustained with age. Accordingly, deiodinase enzymatic activities differed in male and female kidneys, largely independent of age [average of 6.8 vs. 15.7 pmol/(min mg) in males vs. females]. In parallel, hepatic Se concentrations and glutathione peroxidase activities increased in female mice compared to male littermates, establishing a new sexual dimorphism in liver. Thus, age represents another important modifier of the dynamic sex- and tissue-specific selenoprotein expression patterns. These data highlight again the unique physiological regulatory mechanisms that have evolved to control Se metabolism according to the actual needs of the organism.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Age Factors
  • Animals
  • Female
  • Gene Expression Regulation*
  • Iodide Peroxidase / genetics
  • Iodide Peroxidase / metabolism
  • Kidney / metabolism
  • Liver / metabolism
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Models, Biological
  • RNA, Messenger / metabolism
  • Selenoproteins / genetics*
  • Selenoproteins / metabolism
  • Sex Characteristics*

Substances

  • RNA, Messenger
  • Selenoproteins
  • Iodide Peroxidase
  • selenodeiodinase type 1, mouse