The changes of gene expression of iron transporters for duodenal iron uptake and export in diet-induced obese mice

Abstract

This study aims to determine the gene expression changes of iron transporters-divalent metal transporter 1 (DMT1) and ferroportin 1 (Fpn1) in the duodenal tissue of diet-induced obese mice. C57BL/6J mice were randomly divided into normal control (NC) and obesity model (OM) group, 6 in each, and fed on conventional and high-fat diet respectively for 14 weeks by table of random number. Then the DMT1 and Fpn1 mRNA contents in duodenal tissues of the animals were measured by Real-time PCR method, and the protein expression levels were analyzed by Western blot test. The Real-time PCR detection results showed that, compared with the NC group for which the mRNA expression level was defined as 1.0, the Fpn1 mRNA expression in OM group (0.58±0.11) was reduced significantly (t = 6.71, P = 0.014), whereas the relative expression level of DMT1 mRNA in OM group (0.89±0.26) showed no obvious alteration (t = 2.01, P = 0.122). Western blot results showed that the relative protein expression levels of Fpn1 in OM and NC group were 0.32±0.06 and 0.65±0.19, respectively, and the difference was statistically significant (t = 5.37, P = 0.026). The DMT1 protein relative abundance was 0.88±0.21 in OM group and 0.92±0.17 in NC group, and the difference has no statistical significance (t = 1.84, P = 0.185). Fpn1 gene expression is inhibited in the duodenum of diet-induced obesity mouse while DMT1 expression keeps unchanged, and this implies that decreased iron export from enterocytes into circulation might be responsible for the impaired iron absorption in obesity.