Dietary iron-deficient anemia induces a variety of metabolic changes and even apoptosis in rat liver: a DNA microarray study

Abstract

Anemia can be induced by dietary iron deficiency, as well as by hemorrhagia. It may also be associated with changes in lipid metabolism. However, no global analysis detailing the consequences of iron deficiency in the liver has yet been conducted. Since the liver is a metabolically important organ and also a major iron-storing organ, we performed a comprehensive transcriptome analysis to determine the effects of iron deficiency on hepatic gene expression. Four-week-old rats were fed an iron-deficient diet, ∼3 ppm iron, ad libitum for 16 days. These rats were compared with similar rats pair-fed a control diet with a normal iron level, 48 ppm iron. The 16-day iron-deficient diet apparently induced anemia. On day 17, the rats were killed under anesthesia, and their livers were dissected for DNA microarray analysis. We identified 600 upregulated and 500 downregulated probe sets that characterized the iron-deficient diet group. In the upregulated probe sets, genes involved in cholesterol, amino acid, and glucose metabolism were significantly enriched, while genes related to lipid metabolism were significantly enriched in the downregulated probe sets. We also found that genes for caspases 3 and 12, which mediate endoplasmic reticulum (ER)-specific apoptosis, were upregulated in the iron-deficient group. Combined, these results suggest that iron deficiency exerts various influences, not only on nutrient metabolism but also on apoptosis, as a consequence of ER stress in the liver.