scholarly journals The Divalent Metal Transporter 1 (DMT1) Is Required for Iron Uptake and Normal Development of Oligodendrocyte Progenitor Cells

2018 ◽  
Vol 38 (43) ◽  
pp. 9142-9159 ◽  
Author(s):  
Veronica T. Cheli ◽  
Diara A. Santiago González ◽  
Leandro N. Marziali ◽  
Norma N. Zamora ◽  
María E. Guitart ◽  
...  
Keyword(s):  
Progenitor Cells ◽  
Iron Uptake ◽  
Normal Development ◽  
Divalent Metal ◽  
Oligodendrocyte Progenitor Cells ◽  
Divalent Metal Transporter 1 ◽  
Oligodendrocyte Progenitor ◽  
Divalent Metal Transporter ◽  
Metal Transporter

scholarly journals Small molecule inhibitors of divalent metal transporter-1

2009 ◽  
Vol 296 (4) ◽  
pp. G798-G804 ◽  
Author(s):  
Peter D. Buckett ◽  
Marianne Wessling-Resnick
Keyword(s):  
Small Molecule ◽  
Iron Metabolism ◽  
Iron Uptake ◽  
Small Molecule Inhibitors ◽  
Structural Features ◽  
Divalent Metal ◽  
Divalent Metal Transporter 1 ◽  
Divalent Metal Transporter ◽  
Copper Chelation ◽  
Metal Transporter

Divalent metal transporter-1 (DMT1) is a divalent cation transporter that plays a key role in iron metabolism by mediating ferrous iron uptake across the small intestine. We have previously identified several small molecule inhibitors of iron uptake ( 4 ). Using a cell line that stably overexpresses DMT1, we screened the ability of these inhibitors to specifically block this transporter's activity. One compound, NSC306711, inhibited DMT1-mediated iron uptake in a reversible and competitive manner. This inhibitor is a polysulfonated dye containing two copper centers. Although one of these two sites could be chelated by Triethylenetetramine copper chelation did not perturb NSC306711 inhibition of DMT1 activity. Several other polysulfonated dyes with structural features similar to NSC306711 were identified as potential DMT1 transport inhibitors. This study characterizes important pharmacological tools that can be used to probe DMT1's mechanism of iron transport and its role in iron metabolism.

Cytokine-mediated regulation of iron transport in human monocytic cells

Blood ◽  
2003 ◽  
Vol 101 (10) ◽  
pp. 4148-4154 ◽  
Author(s):  
Susanne Ludwiczek ◽  
Elmar Aigner ◽  
Igor Theurl ◽  
Günter Weiss
Keyword(s):  
Iron Uptake ◽  
Iron Transport ◽  
Divalent Metal ◽  
Mrna Levels ◽  
Divalent Metal Transporter 1 ◽  
Divalent Metal Transporter ◽  
Regulatory Pathways ◽  
Metal Transporter ◽  
Cellular Expression ◽  
Ifn Γ

Abstract Under chronic inflammatory conditions cytokines induce a diversion of iron traffic, leading to hypoferremia and retention of the metal within the reticuloendothelial system. However, the regulatory pathways underlying these disturbances of iron homeostasis are poorly understood. We investigated transferrin receptor (TfR)–dependent and –independent iron transport mechanisms in cytokine-stimulated human monocytic cell lines THP-1 and U937. Combined treatment of cells with interferon-γ (IFN-γ) and lipopolysaccharide (LPS) reduced TfR mRNA levels, surface expression, and iron uptake, and these effects were reversed by interleukin-10 (IL-10), thus stimulating TfR-mediated iron acquisition. IFN-γ and LPS dose-dependently increased the cellular expression of divalent metal transporter-1, a transmembrane transporter of ferrous iron, and stimulated the uptake of nontransferrin bound iron (NTBI) into cells. At the same time, IFN-γ and LPS down-regulated the expression of ferroportin mRNA, a putative iron exporter, and decreased iron release from monocytes. Preincubation with IL-10 partly counteracted these effects. Our results demonstrate that the proinflammatory stimuli IFN-γ and LPS increase the uptake of NTBI via stimulation of divalent metal transporter-1 expression and cause retention of the metal within monocytes by down-regulating ferroportin synthesis. Opposite, the anti-inflammatory cytokine IL-10 stimulates TfR-mediated iron uptake into activated monocytes. The regulation of iron transport by cytokines is a key mechanism in the pathogenesis of anemia of chronic disease and a promising target for therapeutic intervention.

scholarly journals Regulation of divalent metal transporter-1 by serine phosphorylation

2016 ◽  
Vol 473 (22) ◽  
pp. 4243-4254 ◽  
Author(s):  
Young Ah Seo ◽  
Ruvin Kumara ◽  
Herbert Wetli ◽  
Marianne Wessling-Resnick
Keyword(s):  
Iron Uptake ◽  
Kinase Inhibitors ◽  
Cannabinoid Receptor ◽  
Phosphorylation Site ◽  
Divalent Metal ◽  
Serine Phosphorylation ◽  
Divalent Metal Transporter 1 ◽  
Divalent Metal Transporter ◽  
Metal Transporter ◽  
Directed Mutation

Divalent metal transporter-1 (DMT1) mediates dietary iron uptake across the intestinal mucosa and facilitates peripheral delivery of iron released by transferrin in the endosome. Here, we report that classical cannabinoids (Δ9-tetrahydrocannabinol, Δ9-THC), nonclassical cannabinoids (CP 55,940), aminoalkylindoles (WIN 55,212-2) and endocannabinoids (anandamide) reduce 55Fe and 54Mn uptake by HEK293T(DMT1) cells stably expressing the transporter. siRNA knockdown of cannabinoid receptor type 2 (CB2) abrogated inhibition. CB2 is a G-protein (GTP-binding protein)-coupled receptor that negatively regulates signal transduction cascades involving serine/threonine kinases. Immunoprecipitation experiments showed that DMT1 is serine-phosphorylated under basal conditions, but that treatment with Δ9-THC reduced phosphorylation. Site-directed mutation of predicted DMT1 phosphosites further showed that substitution of serine with alanine at N-terminal position 43 (S43A) abolished basal phosphorylation. Concordantly, both the rate and extent of 55Fe uptake in cells expressing DMT1(S43A) was reduced compared with those expressing wild-type DMT1. Among kinase inhibitors that affected DMT1-mediated iron uptake, staurosporine also reduced DMT1 phosphorylation confirming a role for serine phosphorylation in iron transport regulation. These combined data indicate that phosphorylation at serine 43 of DMT1 promotes transport activity, whereas dephosphorylation is associated with loss of iron uptake. Since anti-inflammatory actions mediated through CB2 would be associated with reduced DMT1 phosphorylation, we postulate that this pathway provides a means to reduce oxidative stress by limiting iron uptake.

Two routes of iron accumulation in astrocytes: ascorbate-dependent ferrous iron uptake via the divalent metal transporter (DMT1) plus an independent route for ferric iron

2010 ◽  
Vol 432 (1) ◽  
pp. 123-132 ◽  
Author(s):  
Darius J.R. Lane ◽  
Stephen R. Robinson ◽  
Hania Czerwinska ◽  
Glenda M. Bishop ◽  
Alfons Lawen
Keyword(s):  
Iron Uptake ◽  
Divalent Metal ◽  
Iron Accumulation ◽  
Mammalian Brain ◽  
Divalent Metal Transporter 1 ◽  
Divalent Metal Transporter ◽  
Metal Transporter ◽  
Uptake Pathway ◽  
Cultured Astrocytes

Astrocytes are central to iron and ascorbate homoeostasis within the brain. Although NTBI (non-transferrin-bound iron) may be a major form of iron imported by astrocytes in vivo, the mechanisms responsible remain unclear. The present study examines NTBI uptake by cultured astrocytes and the involvement of ascorbate and DMT1 (divalent metal transporter 1). We demonstrate that iron accumulation by ascorbate-deficient astrocytes is insensitive to both membrane-impermeant Fe(II) chelators and to the addition of the ferroxidase caeruloplasmin. However, when astrocytes are ascorbate-replete, as occurs in vivo, their rate of iron accumulation is doubled. The acquisition of this additional iron depends on effluxed ascorbate and can be blocked by the DMT1 inhibitor ferristatin/NSC306711. Furthermore, the calcein-accessible component of intracellular labile iron, which appears during iron uptake, appears to consist of only Fe(III) in ascorbate-deficient astrocytes, whereas that of ascorbate-replete astrocytes comprises both valencies. Our data suggest that an Fe(III)-uptake pathway predominates when astrocytes are ascorbate-deficient, but that in ascorbate-replete astrocytes, at least half of the accumulated iron is initially reduced by effluxed ascorbate and then imported by DMT1. These results suggest that ascorbate is intimately involved in iron accumulation by astrocytes, and is thus an important contributor to iron homoeostasis in the mammalian brain.

Sign in / Sign up

Export Citation Format

Share Document