Effects of various metal ions on the gene expression of iron exporter ferroportin-1 in J774 macrophages
1
조회
0
다운로드
1
인용
0
참고문헌
키워드
초록
Macrophages play a key role in iron metabolism by recycling iron through erythrophagocytosis. Ferroportin-1 (FPN1) is a transporter protein that is known to mediate iron export from macrophages. Since divalent metals often interact with iron metabolism, we examined if divalent metals could regulate the expression of FPN1 in macrophages. J774 macrophage cells were treated with copper, manganese, zinc, or cobalt at 10, 50, or 100 μM for 16 to 24 h. Then, FPN1 mRNA and protein levels were determined by quantitative real-time PCR and Western blot analyses, respectively. In addition, effects of divalent metals on FPN1 promoter activity were examined by luciferase reporter assays. Results showed that copper significantly increased FPN1 mRNA levels in a dose-dependent manner. The copper-induced expression of FPN1 mRNA was associated with a corresponding increase in FPN1 protein levels. Also, copper directly stimulated the activity of FPN1 promoter-driven reporter construct. In contrast, manganese and zinc had no effect on the FPN1 gene expression in J774 cells. Interestingly, cobalt treatment in J774 cells decreased FPN1 protein levels without affecting FPN1 mRNA levels. In conclusion, our study results demonstrate that divalent metals differentially regulate FPN1 expression in macrophages and indicate a potential interaction of divalent metals with the FPN1-mediated iron export in macrophages.
Abstract
Macrophages play a key role in iron metabolism by recycling iron through erythrophagocytosis. Ferroportin-1 (FPN1) is a transporter protein that is known to mediate iron export from macrophages. Since divalent metals often interact with iron metabolism, we examined if divalent metals could regulate the expression of FPN1 in macrophages. J774 macrophage cells were treated with copper, manganese, zinc, or cobalt at 10, 50, or 100 μM for 16 to 24 h. Then, FPN1 mRNA and protein levels were determined by quantitative real-time PCR and Western blot analyses, respectively. In addition, effects of divalent metals on FPN1 promoter activity were examined by luciferase reporter assays. Results showed that copper significantly increased FPN1 mRNA levels in a dose-dependent manner. The copper-induced expression of FPN1 mRNA was associated with a corresponding increase in FPN1 protein levels. Also, copper directly stimulated the activity of FPN1 promoter-driven reporter construct. In contrast, manganese and zinc had no effect on the FPN1 gene expression in J774 cells. Interestingly, cobalt treatment in J774 cells decreased FPN1 protein levels without affecting FPN1 mRNA levels. In conclusion, our study results demonstrate that divalent metals differentially regulate FPN1 expression in macrophages and indicate a potential interaction of divalent metals with the FPN1-mediated iron export in macrophages.
참고문헌 (29)
- Abboud S, "A novel mammalian iron-regulated protein involved in intracellular iron metabolism", J Biol Chem, 275, pp.19906~19912 (2000)
- Aigner E, "Copper availability contributes to iron perturbations in human nonalcoholic fatty liver disease", Gastroenterology, 135, pp.680~688 (2008)
- Andersen HS, "Effect of dietary copper deficiency on iron metabolism in the pregnant rat", Br J Nutr, 97, pp.239~246 (2007)
- Beutler E, "Hemochromatosis: genetics and pathophysiology", Annu Rev Med, 57, pp.331~347 (2006)
- Chung J, "Copper-induced ferroportin-1 expression in J774 macrophages is associated with increased iron efflux", Proc Natl Acad Sci U S A, 통권 : 101, pp.2700~2705 (2004)
- Cuthbert JA, "Wilson's disease: a new gene and an animal model for an old disease", J Investig Med, 43, pp.323~336 (1995)
- Donovan A, "Positional cloning of zebrafish ferroportin1 identifies a conserved vertebrate iron exporter", Nature, 403, pp.776~781 (2000)
- Ganz T, "Regulation of iron acquisition and iron distribution in mammals", Biochim Biophys Acta, 1763, pp.690~699 (2006)
- Giedroc DP, "Metal response element (MRE)-binding transcription factor-1 (MTF-1): structure, function, and regulation", Antioxid Redox Signal, 3, pp.577~596 (2001)
- Gonzalez M, "Expression of copper-related genes in response to copper load", Am J Clin Nutr, 88, pp.830S~834S (2008)
- Gunshin H, "Cloning and characterization of a mammalian proton-coupled metal-ion transporter", Nature, 388, pp.482~488 (1997)
- Hunt JR, "Zinc absorption, mineral balance, and blood lipids in women consuming controlled lactoovovegetarian and omnivorous diets for 8 wk", Am J Clin Nutr, 67, pp.421~430 (1998)
- Itoh S, "Novel role of antioxidant-1 (Atox1) as a copper-dependent transcription factor involved in cell proliferation", J Biol Chem, 283, pp.9157~9167 (2008)
- Knutson MD, "Iron release from macrophages after erythrophagocytosis is up-regulated by ferroportin 1 overexpression and down-regulated by hepcidin", Proc Natl Acad Sci U S A, 통권 : 102, pp.1324~1328 (2005)
- Knutson MD, "Iron loading and erythrophagocytosis increase ferroportin 1 (FPN1) expression in J774 macrophages", Blood, 102, pp.4191~4197 (2003)
- Li GJ, "Occupational exposure to welding fume among welders: alterations of manganese, iron, zinc, copper, and lead in body fluids and the oxidative stress status", J Occup Environ Med, 46, pp.241~248 (2004)
- Liu XB, "Role of the ferroportin iron-responsive element in iron and nitric oxide dependent gene regulation", Blood Cells Mol Dis, 29, pp.315~326 (2002)
- Ludwiczek S, "Cytokinemediated regulation of iron transport in human monocytic cells", Blood, 101, pp.4148~4154 (2003)
- Mattie MD, "Copper-inducible transcription: regulation by metal- and oxidative stress-responsive pathways", Am J Physiol Cell Physiol, 286, pp.C293~301 (2004)
- McKie AT, "A novel duodenal iron-regulated transporter, IREG1, implicated in the basolateral transfer of iron to the circulation", Mol Cell, 5, pp.299~309 (2000)
- Muller PA, "ATOX1: A novel copper-responsive transcription factor in mammals?", Int J Biochem Cell Biol, BC-2807, pp.1~4 (2008)
- Muller PA, "Gene expression profiling of liver cells after copper overload in vivo and in vitro reveals new copper-regulated genes", J Biol Inorg Chem, 12, pp.495~507 (2007)
- Pietrangelo A, "The ferroportin disease", Blood Cells Mol Dis, 32, pp.131~138 (2004)
- Song IS, "Transcription factor Sp1 plays an important role in the regulation of copper homeostasis in mammalian cells", Mol Pharmacol, 74, pp.705~713 (2008)
- Wang X, "Intracellular localization and subsequent redistribution of metal transporters in a rat choroid plexus model following exposure to manganese or iron", Toxicol Appl Pharmacol, 230, pp.167~174 (2008)
- Weiss G, "Iron and immunity: a double-edged sword", Eur J Clin Invest, 32, pp.70~78 (2002)
- Yamaji S, "Zinc regulates the function and expression of the iron transporters DMT1 and IREG1 in human intestinal Caco-2 cells", FEBS Lett, 507, pp.137~141 (2001)
- Yang F, "Regulation of reticuloendothelial iron transporter MTP1 (Slc11a3) by inflammation", J Biol Chem, 277, pp.39786~39791 (2002)
- Yang F, "Iron increases expression of iron-export protein MTP1 in lung cells", Am J Physiol Lung Cell Mol Physiol, 283, pp.L932~L939 (2002)