Selenium regulates expression in rat liver of genes for proteins involved in iron metabolism

Suppression subtractive hybridization analysis in our laboratory recently revealed that transferrin mRNA may be elevated in Sedeficient rat liver. In this work, we compared expression in rat liver of genes for transferrin, transferrin receptor, ferritin light and heavy chains, and iron-regulatory proteins 1 and 2 in Se adequacy and deficiency. Weanling male Sprague-Dawley rats were fed Torula yeast diets supplemented with 0 or 0.15 µg Se/kg diet as sodium selenite for 15 wk. Activity of cellular glutathione peroxidase was virtually abolished in Se-deficient rat liver, whereas activity of glutathione S-transferase was 43% higher than in Se-adequate liver. There were no differences in hematocrit, hemoglobin, or liver iron content. To examine differential gene expression, we used a multiplex relative reverse transcriptase-polymerase chain reaction method. Three of the six genes examined showed modest but consistent upregulation in Se deficiency. Transferrin mRNA was 30% more abundant in Sedeficient than in Se-adequate liver. For the transferrin receptor, the difference was 32%, and for iron regulatory protein 1, it was 63%. No consistent differences were observed for iron regulatory protein 2 or for ferritin light or heavy chain. These findings suggest a possible role for dietary Se in moderating iron metabolism.