Expression of Divalent Metal Transporter 1 (DMT1) and Ferroportin 1 (FP1) in the Duodenum of Hepatitis C Virus (HCV)-Infected Patients

Abstract

Purpose: Studies documented increased hepatic iron deposition in some HCV-infected patients, and several authors have implicated this histologic change in the progression of liver disease or in the non-response to combined interferon/ribavirin therapy. The exact mechanism underlying this observation remains elusive. We hypothesize that the expression of DMT1 and FP1 in duodenal mucosa may play an important role in the pathogenesis of HCV-associated hepatic iron overload. The study aims to assess the expression of DMT1 in HCV-infecetd patients. Methods: A total of 36 specimens (20 HCV- infected patients and 16 non-HCV infected patients) were studied. All study subjects underwent gastroscopy as work-up for other gastrointestinal disorders and had biopsies taken from the second part of duodenum. Hematologic parameters were measured within 7 days of gastroscopy. Biopsies were snap frozen in liquid nitrogen immediately and stored at -700 C for total RNA extraction. Total RNA were extracted from two pooled duodenal biopsy specimens from each subject using TRIzol reagent. Real Time PCR were performed on total RNA extracted from specimens. For quantification of DMT1 complementary DNA (cDNA), the following primers were used: 5'GTGGTCAGCGTGGCTTATCTG-3', 5'-GATGCT TACCGTATGCCCACAGT-3'; the TaqMan probe 5'TGTTC-TACT TGGGTTGGCAATGTTTGATTGC-3' were labeled with the reporter fluorescent dye 6-carboxyfluorescein (FAM) at the 5' end and with the quencher 6-carboxytetramethyl-rhodamine (TAMRA) at the 3' end. For quantification of FP1, specific primers were used. Results: HCV-infected patients have a significantly higher DMT1 gene expression than the non-HCV patients, Figure 1. Conclusion: This study documents for the first time increased expression of duodenal DMT1 gene in a subset of HCV infected patients. This may explain the observed hepatic iron overload in this subset of patients.Figure