• Nutrition Research and Practice
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• v.2 no.4
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• pp.317-321
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• 2008

Macrophages play a key role in iron metabolism by recycling iron through erythrophagocytosis. Ferroportin-l (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 $100\;{\mu}M$ 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.

• Proceedings of the Korean Society of Applied Pharmacology
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• 2001.11a
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• pp.91-91
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• 2001

Nramp2, also known as DMT1 and DCT1, is a 12-transmembrane domain protein responsible for dietary iron uptake as well as metal ions such as lead, manganese, zinc, copper, nickel, cadmium, and cobalt. High expression of DMT1 increase lead uptake, and DMT1-dependent lead transport was H -dependent and inhibited by iron ions. The molecular mechanism of lead transport in CNS is as yet unknown. although interactions between iron and lead at the level of absorption have been known for some time. The process of lead uptake into astrocytes was not known yet. Nramp2 may mediate transport of heavy metal into astrocytes. We investigated whether Nramp2 mediate transport of lead into astrocytes. And we do whether Nramp2 was expressed highly by deprivation of iron in Astrocytes, and lead uptake into astrocytes was influenced by expression of Nramp2. Immortalized human fetal astrocyte(SV-FHA) cells were cultured in medium containing Dulbecco's modified Eagle's medium and treated with Deferoxamine. Northern blot analysis was done for determining mRNA level of DMT1 and lead uptake assay was done in incubation condition of pH 5.5 and 7.4.

• Environmental Analysis Health and Toxicology
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• v.19 no.4
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• pp.389-399
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• 2004

Metallothionein (MT), a small protein molecule which can bind or release metal ions, is involved in the regulation of cellular metal homeostasis. This study was investigated the accumulation of cadmium in blood, tissue (liver, kidney and brain), and the effect of cadmium on several key genes (MT-I, MT-II, ZnT-1) in zinc metabolism in the mouse. Mouses weighing 20∼25 g were randomly assigned to control and cadmium treated group (Cd group). Cd group was intraperitoneally injected with cadmium 2, 4, 8 mg/kg and control group was administerd with saline. Mouses of each group were sacrificed by decapitation 4 hours after the administration of cadmium. Cadmium contents in blood, liver, kidney and brain were increased by a dose-dependent manner. Accumulation of cadmium was mainly occurred in liver and kidney. Induction of MT-I and MT-II protein was increased, but ZnT-1 expression was decreased in a dose-dependent manner by the treatment of 2∼8 mg/kg cadmium. These results suggested that cadmium can be transported to brain and alter the expression of several key genes in zinc homeostasis.

• Journal of Microbiology and Biotechnology
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• v.26 no.6
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• pp.1132-1139
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• 2016

Brucellosis is a zoonotic disease caused by Brucella, a genus of gram-negative bacteria. Cytokines have key roles in the activation of innate and acquired immunities. Despite several research attempts to reveal the immune responses, the mechanism of Brucella infection remains unclear. Therefore, immune responses were analyzed in mice immunized with nine recombinant proteins. Cytokine production profiles were analyzed in the RAW 264.7 cells and naive splenocytes after stimulation with three recombinant proteins, metal-dependent hydrolase (r0628), bacterioferritin (rBfr), and thiamine transporter substrate-binding protein (rTbpA). Immune responses were analyzed by ELISA and ELISpot assay after immunization with proteins in mice. The production levels of NO, TNF-α, and IL-6 were time-dependently increased after having been stimulated with proteins in the RAW 264.7 cells. In naive splenocytes, the production of IFN-γ and IL-2 was increased after stimulation with the proteins. It was concluded that two recombinant proteins, r0628 and rTbpA, showed strong immunogenicity that was induced with Th1-related cytokines IFN-γ, IL-2, and TNF-α more than Th2-related cytokines IL-6, IL-4, and IL-5 in vitro. Conversely, a humoral immune response was activated by increasing the number of antigen-secreting cells specifically. Furthermore, these could be candidate diagnosis antigens for better understanding of brucellosis.

• Journal of Nutrition and Health
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• v.42 no.5
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• pp.434-441
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• 2009

Ferroportin-1 (FPN) is a transporter protein that is known to mediate iron export from macrophages. The purpose of this study was to investigate the effect of copper on the regulation of FPN gene expression in J774 mouse macrophage cells. J774 cells were treated with various concentrations of $CuSO_4$ and RT-PCR analyses were performed to measure the steady-state levels of mRNAs for FPN and divalent metal transporter 1 (DMT1, an iron importer). Copper treatment significantly increased FPN mRNAs in a dose-dependent manner, but didn't change the levels of DMT1 mRNA. Experiments with transcriptional inhibitor actinomycin D (0.5 ${\mu}g$/mL) revealed that copper treatment did not affect the half-life of FPN mRNAs in J774 cells. On the other hand, results from luciferase reporter assays showed that copper directly stimulated the promoter activity of FPN. In summary, our data showed copper induced FPN mRNA of macrophages via a transcriptional rather than post-transcriptional mechanisms.