Iron regulates the expression of ferroportin 1 in the cultured hFOB 1.19 osteoblast cell line.

Guo-Yang Zhao,Peng Zhang,You-Jia Xu,Bo Wang,Dong-Hua Di

doi:10.3892/etm.2014.1823

Abstract

Iron metabolism is tightly regulated in osteoblasts, and ferroportin 1 (FPN1) is the only identified iron exporter in mammals to date. In the present study, the regulation of FNP1 in human osteoblasts was investigated following various iron treatments. The human osteoblast cell line hFOB 1.19 was treated with ferric ammonium citrate (FAC) or desferrioxamine (DFO) of various concentrations. The intracellular iron ion levels were measured using a confocal laser scanning microscope. In addition, the mRNA and protein expression levels of FPN1 were detected by quantitative polymerase chain reaction, western blot analysis and immunofluorescence. The results demonstrated that increasing iron concentrations via FAC treatment increased the expression of FPN1. By contrast, decreasing the iron concentration by DFO treatment decreased FNP1 expression levels. In addition to demonstrating that the FNP1 expression changed according to the iron concentration, the observations indicated that changes in FPN1 expression may contribute to the maintenance of the intracellular iron balance in osteoblasts.

Highlights

Iron is one of the most important trace elements found in the human body
MRNA and protein expression levels of ferroportin 1 (FPN1) following treatment with ferric ammonium citrate (FAC) and DFO. quantitative polymerase chain reaction (qPCR) revealed that the mRNA expression levels of FPN1 in osteoblasts increased with increasing concentrations of FAC in a concentration‐dependent manner, whereas they decreased with increasing concentrations of DFO in a concentration‐dependent manner (P
In 2003, Knutson et al [18] reported that iron excess increased the mRNA expression levels of FPN1, while iron deficiency decreased the mRNA expression levels of FPN1 in murine J744 macrophages. This effect was completely inhibited by actinomycin D, an inhibitor of RNA polymerase. The results of these studies indicated that the regulation of FPN1 by iron occurs at a transcriptional level in macrophages

Summary

Introduction

Iron is one of the most important trace elements found in the human body. A number of studies have indicated that bone metabolism is closely associated with iron metabolism. Hepcidin (a peptide hormone that decreases iron levels in the body) has been investigated for the treatment of osteoporosis in peri‐ and post‐menopausal females [6]. These studies indicate that iron plays an important role in bone metabolism. Research into the mechanisms underlying the iron balance in bone cells is crucial to improve the understanding of the pathogenesis and treatment of iron‐associated bone disease

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