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Andrew T. Mckie - One of the best experts on this subject based on the ideXlab platform.
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<B>DuodenalB> Reductase Activity and Spleen Iron Stores Are Reduced and Erythropoiesis Is ABnormal in DcytB Knockout Mice Exposed to Hypoxic Conditions
The Journal of nutrition, 2012Co-Authors: Jeehyea Choi, Gladys O. Latunde-dada, Robert J. Simpson, Patarabutr Masaratana, Matthew Arno, Andrew T. MckieAbstract:<B>DuodenalB> <B>CytochromeB> B (DcytB, CyBrd1) is a ferric reductase localized in the duodenum that is highly upregulated in circumstances of increased iron aBsorption. To address the contriBution of DcytB to total <B>DuodenalB> ferric reductase activity as well as its wider role in iron metaBolism, we first measured <B>DuodenalB> ferric reductase activity in wild-type (WT) and DcytB knockout (DcytB(-/-)) mice under 3 conditions known to induce gut ferric reductase: dietary iron deficiency, hypoxia, and pregnancy. DcytB(-/-) and WT mice were randomly assigned to control (iron deficiency experiment, 48 mg/kg dietary iron; hypoxia experiment, normal atmospheric pressure; pregnancy experiment, nonpregnant animals) or treatment (iron deficiency experiment, 2-3 mg/kg dietary iron; hypoxia experiment, 53.3 kPa pressure; pregnancy experiment, d 20 of pregnancy) groups and <B>DuodenalB> reductase activity measured. We found no induction of ferric reductase activity in DcytB(-/-) mice under any of these conditions, indicating there are no other induciBle ferric reductases present in the duodenum. To test whether DcytB was required for iron aBsorption in conditions with increased erythropoietic demand, we also measured tissue nonheme iron levels and hematological indices in WT and DcytB(-/-) mice exposed to hypoxia. There was no evidence of gross alterations in iron aBsorption, hemogloBin, or total liver nonheme iron in DcytB(-/-) mice exposed to hypoxia compared with WT mice. However, spleen nonheme iron was significantly less (6.7 ± 1.0 vs. 12.7 ± 0.9 nmol · mg tissue(-1); P < 0.01, n = 7-8) in hypoxic DcytB(-/-) compared with hypoxic WT mice and there was evidence of impaired reticulocyte hemogloBinization with a lower reticulocyte mean corpuscular hemogloBin (276 ± 1 vs. 283 ± 2 g · L(-1); P < 0.05, n = 7-8) in normoxic DcytB(-/-) compared with normoxic WT mice. We therefore conclude that DCYTB is the primary iron-regulated <B>DuodenalB> ferric reductase in the gut and that DcytB is necessary for optimal iron metaBolism.
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<B>DuodenalB> <B>CytochromeB> B (CyBrd 1) and HIF-2α expression during acute hypoxic exposure in mice
European Journal of Nutrition, 2011Co-Authors: Gladys O. Latunde-dada, Robert J. Simpson, Lan Xiang, Andrew T. MckieAbstract:Background Recent evidence suggests that the duodenum can regulate iron aBsorption independently of hepcidin via the transcription factor Hif-2α acting directly on the transcription of the proteins involved in the iron transport. The current study investigates the temporal relationship Between DcytB and Hif-2α during early hypoxic stimulus in the enterocyte in vivo. Methods <B>DuodenalB> DcytB and Hif-2α protein expression was analysed By Western Blot technique while gene regulation was determined By quantitative PCR. Results Both DcytB and Hif-2α protein expression were increased during the first hours of hypoxic duration. A change in hepcidin expression however, was significant only at 72 h hypoxia. Increased iron aBsorption reported in early hypoxia could Be accounted for in part By the enhancement of DcytB expression By Hif-2α in the duodenum. Conclusion Modulation of Hif-2α predominates over hepcidin in the regulation of intestinal iron aBsorption during short hypoxic duration. The intestine exerts regulatory mechanisms in the dietary aBsorption of iron into systemic circulation.
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<B>DuodenalB> <B>CytochromeB> B (CyBrd 1) and HIF-2α expression during acute hypoxic exposure in mice.
European journal of nutrition, 2011Co-Authors: Gladys O. Latunde-dada, Robert J. Simpson, Lan Xiang, Andrew T. MckieAbstract:Background Recent evidence suggests that the duodenum can regulate iron aBsorption independently of hepcidin via the transcription factor Hif-2α acting directly on the transcription of the proteins involved in the iron transport. The current study investigates the temporal relationship Between DcytB and Hif-2α during early hypoxic stimulus in the enterocyte in vivo.
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<B>DuodenalB> <B>CytochromeB> B Expression Stimulates Iron Uptake By Human Intestinal Epithelial Cells
The Journal of nutrition, 2008Co-Authors: Gladys O. Latunde-dada, Robert J. Simpson, Andrew T. MckieAbstract:<B>DuodenalB> <B>CytochromeB> B (DcytB) is localized principally in the apical memBrane of the enterocyte. It is thought to act as a ferric reductase that furnishes Fe(II), the specific and selective iron species transported By divalent metal transporter 1 (DMT1) in the <B>DuodenalB> enterocytes. Expression of Both genes is strongly iron regulated and is thought to Be required for transcellular iron trafficking in concert in response to physiological requirements. We tested this hypothesis By expressing DcytB in Caco-2 cells, a human cell line model often used to mimic intestinal enterocytes. Iron uptake (59Fe) was significantly higher in DcytB-transfected Caco-2 cells than in cells transfected with empty vector as a control. Fe(III) reductase activity of DcytB was measured with ferrozine, a strong chelator of Fe(II) species. Cells expressing DcytB exhiBited enhanced ferric reductase activity as well as increased 59Fe uptake compared with cells transfected with empty vector as a control. Ferrozine Blocked iron uptake and preincuBation of cells with dehydroascorBate (to increase cellular ascorBate levels) stimulated iron uptake. Cotransfection of DcytB and DMT1 resulted in an additive increase in iron uptake By the cells. The results confirm DcytB can act as a ferric reductase that stimulates iron uptake in Caco-2 cells.
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DcytB (CyBrd1) functions as Both a ferric and a cupric reductase in vitro.
FEBS letters, 2008Co-Authors: Steven Wyman, Andrew T. Mckie, Robert J. Simpson, Phillip A. SharpAbstract:MDCK cells expressing an induciBle <B>DuodenalB> <B>CytochromeB> B-green fluorescent protein (DcytB-EGFP) fusion construct were used to investigate the function of DcytB. The DcytB-EGFP protein was targeted correctly to the plasma memBrane, and cells displayed increased ferric and cupric reductase activities, which were greatly reduced in the presence of doxycycline. The data suggests that DcytB plays a physiological role in Both iron and copper uptake, through divalent metal transporter 1 (DMT1) and copper transporter 1, respectively. In support of this hypothesis, we show that 59Fe uptake was significantly enhanced in DcytB-EGFP expressing MDCK cells which endogenously express DMT1.
Gregory J. Anderson - One of the best experts on this subject based on the ideXlab platform.
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intestinal iron aBsorption
Journal of Trace Elements in Medicine and Biology, 2012Co-Authors: Brie K Fuqua, Christopher D. Vulpe, Gregory J. AndersonAbstract:Intestinal iron aBsorption is a critical process for maintaining Body iron levels within the optimal physiological range. Iron in the diet is found in a wide variety of forms, But the aBsorption of non-heme iron is Best understood. Most of this iron is moved across the enterocyte Brush Border memBrane By the iron transporter divalent metal-ion transporter 1, a process enhanced By the prior reduction of the iron By <B>DuodenalB> <B>CytochromeB> B and possiBly other reductases. Enterocyte iron is exported to the Blood via ferroportin 1 on the Basolateral memBrane. This transporter acts in partnership with the ferroxidase hephaestin that oxidizes exported ferrous iron to facilitate its Binding to plasma transferrin. Iron aBsorption is controlled By a complex network of systemic and local influences. The liver-derived peptide hepcidin Binds to ferroportin, leading to its internalization and a reduction in aBsorption. Hepcidin expression in turn responds to Body iron demands and the BMP-SMAD signaling pathway plays a key role in this process. The levels of iron and oxygen in the enterocyte also exert important influences on iron aBsorption. DisturBances in the regulation of iron aBsorption are responsiBle for Both iron loading and iron deficiency disorders in humans.
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Overexpression of cellular iron import proteins is associated with malignant progression of esophageal adenocarcinoma.
Clinical cancer research : an official journal of the American Association for Cancer Research, 2008Co-Authors: Jessica K.r. Boult, Gregory J. Anderson, Keith J. Roberts, Matthew J. Brookes, Sharon Hughes, Jonathan Bury, Simon S. Cross, Robert Spychal, Tariq Iqbal, Chris TselepisAbstract:Purpose: There is growing evidence that iron is important in esophageal adenocarcinoma, a cancer whose incidence is rising faster than any other in the Western world. However, how iron mediates carcinogenesis at the molecular level remains unclear. In this study, we investigated the expression of iron transport proteins involved in cellular iron import, export, and storage in the premalignant lesion Barrett's metaplasia and esophageal adenocarcinoma. Experimental Design: Perls' staining was used to examine iron deposition in tissue. mRNA expression in samples of Barrett's metaplasia matched with esophageal adenocarcinoma and samples of Barrett's metaplasia without evidence of adenocarcinoma were examined By real-time PCR. Semiquantitative immunohistochemistry was used to examine cellular localization and protein levels. The effect of iron loading on cellular proliferation and iron transporter expression was determined in esophageal cell lines OE33 and SEG-1 using a Bromodeoxyuridine assay and real-time PCR, respectively. Results: In the progression of Barrett's metaplasia to adenocarcinoma, there was overexpression of divalent metal transporter 1 (DMT1), transferrin receptor 1, <B>DuodenalB> <B>CytochromeB> B, ferroportin, and H-ferritin, and these changes were associated with increased iron deposition. Overexpression of DMT1 was further associated with metastatic adenocarcinoma. Iron loading OE33 and SEG-1 cells caused increased cellular proliferation, which was associated with increased H-ferritin and decreased transferrin receptor 1 and DMT1 expression. Conclusions: Progression to adenocarcinoma is associated with increased expression of iron import proteins. These events culminate in increased intracellular iron and cellular proliferation. This may represent a novel mechanism of esophageal carcinogenesis.
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Modulation of iron transport proteins in human colorectal carcinogenesis
Gut, 2006Co-Authors: Matthew J. Brookes, Andrew T. Mckie, Sharon Hughes, Frances E. Turner, Gary M. Reynolds, Naveen Sharma, Tariq Ismail, Geert Berx, Neil A. Hotchin, Gregory J. AndersonAbstract:Background and aims: Total Body iron and high dietary iron intake are risk factors for colorectal cancer. To date there is no comprehensive characterisation of iron transport proteins in progression to colorectal carcinoma. In this study, we examined expression of iron import (<B>DuodenalB> <B>CytochromeB> B (DCYTB), divalent metal transporter 1 (DMT1), and transferrin receptor 1 (TfR1)) and export (hephaestin (HEPH) and ferroportin (FPN)) proteins in colorectal carcinoma. Methods: Perl’s staining was used to examine colonocyte iron content. Real time polymerase chain reaction (PCR) and western Blotting were used to examine mRNA and protein levels of the molecules of interest in 11 human colorectal cancers. Semiquantitative immunohistochemistry was used to verify protein levels and information on cellular localisation. The effect of iron loading on E-cadherin expression in SW480 and Caco-2 cell lines was examined By promoter assays, real time PCR and western Blotting. Results: Perl’s staining showed increased iron in colorectal cancers, and there was a corresponding overexpression of components of the intracellular iron import machinery (DCYTB, DMT1, and TfR1). The iron exporter FPN was also overexpressed, But its intracellular location, comBined with reduced HEPH levels, suggests reduced iron efflux in the majority of colorectal cancers examined. Loss of HEPH and FPN expression was associated with more advanced disease. Iron loading Caco-2 and SW480 cells caused cellular proliferation and E-cadherin repression. Conclusions: Progression to colorectal cancer is associated with increased expression in iron import proteins and a Block in iron export due to decreased expression and aBerrant localisation of HEPH and FPN, respectively. This results in increased intracellular iron which may induce proliferation and repress cell adhesion.
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The role of <B>DuodenalB> <B>CytochromeB> B in intestinal iron aBsorption remains unclear
Blood, 2005Co-Authors: David M. Frazer, Christopher D. Vulpe, Sarah J. Wilkins, Gregory J. AndersonAbstract:<B>DuodenalB> <B>CytochromeB> B (DcytB; encoded By the CyBrd1 gene), a ferric reductase expressed at the Brush Border of <B>DuodenalB> enterocytes,1 has Been proposed to reduce dietary ferric iron, thereBy facilitating its transport into the mucosal cells By the ferrous iron transporter divalent metal transporter 1. To define the role of DcytB in intestinal iron aBsorption, Gunshin et al2 have taken the important step of generating a DcytB knockout mouse. From their analysis of the hepatic iron levels of these animals, they concluded that DcytB is not necessary for dietary iron aBsorption in mice. However, this conclusion should Be interpreted with caution, as no direct measurements of iron aBsorption were made and the reliance on liver iron levels does not provide unequivocal evidence for or against an aBsorption defect. The authors show that CyBrd1-/- mice maintained on standard rodent chow have hepatic iron levels similar to wild-type mice, and at face value this would suggest that DcytB plays no role in iron aBsorption under normal conditions. However, the diet used for these studies (ProlaB RMH 3000 LaBDiet; PMI Richmond, Richmond, IN) contains a large amount of iron (380 mg/kg), including added ferrous iron, and thus Both wild-type and CyBrd1-/- mice would likely aBsorB comparaBle quantities of iron as the ferric iron reduction step is Bypassed. Thus the results oBtained are not unexpected. To adequately define the role of DcytB, direct iron aBsorption studies should Be carried out or the mice should Be maintained on a diet containing ferric iron only. The former approach is preferaBle.
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Delayed hepcidin response explains the lag period in iron aBsorption following a stimulus to increase erythropoiesis
Gut, 2004Co-Authors: David M. Frazer, Christopher D. Vulpe, Andrew T. Mckie, Sarah J. Wilkins, K N Millard, H R Inglis, Teresa M. Steele, Gordon D. Mclaren, Gregory J. AndersonAbstract:Introduction: The delay of several days Between an erythropoietic stimulus and the suBsequent increase in intestinal iron aBsorption is commonly Believed to represent the time required for Body signals to programme the immature crypt enterocytes and for these cells to migrate to the villus. Recent data however suggest that signals from the Body to alter aBsorption are mediated By circulating hepcidin and that this peptide exerts its effect on mature villus enterocytes. Methods: We have examined the delay in the aBsorptive response following stimulated erythropoiesis using phenylhydrazine induced haemolysis and correlated this with expression of hepcidin in the liver and iron transporters in the duodenum. Results: There was a delay of four days following haemolysis Before a significant increase in iron aBsorption was oBserved. Hepatic hepcidin expression did not decrease until day 3, reaching almost undetectaBle levels By days 4 and 5. This coincided with the increase in <B>DuodenalB> expression of divalent metal transporter 1, <B>DuodenalB> <B>CytochromeB> B, and Ireg1. Conclusion: These results suggest that the delayed increase in iron aBsorption following stimulated erythropoiesis is attriButaBle to a lag in the hepcidin response rather than crypt programming, and are consistent with a direct effect of the hepcidin pathway on mature villus enterocytes.
Raymond P. Glahn - One of the best experts on this subject based on the ideXlab platform.
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A Novel in Vivo Model for Assessing the Impact of Geophagic Earth on Iron Status
Nutrients, 2016Co-Authors: Gretchen L. Seim, Raymond P. Glahn, Elad Tako, Cedric Ahn, Sera L. YoungAbstract:The causes and consequences of geophagy, the craving and consumption of earth, remain enigmatic, despite its recognition as a Behavior with puBlic health implications. Iron deficiency has Been proposed as Both a cause and consequence of geophagy, But methodological limitations have precluded a decisive investigation into this relationship. Here we present a novel in vivo model for assessing the impact of geophagic earth on iron status: Gallus gallus (Broiler chicken). For four weeks, animals were gavaged daily with varying dosages of geophagic material or pure clay mineral. Differences in haemogloBin (HB) across treatment groups were assessed weekly and differences in liver ferritin, liver iron, and gene expression of the iron transporters divalent metal transporter 1 (DMT1), <B>DuodenalB> <B>CytochromeB> B (DcytB) and ferroportin were assessed at the end of the study. Minimal impact on iron status indicators was oBserved in all non-control groups, suggesting dosing of geophagic materials may need refining in future studies. However, this model shows clear advantages over prior methods used Both in vitro and in humans, and represents an important step in explaining the puBlic health impact of geophagy on iron status.
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White Beans provide more BioavailaBle iron than red Beans: studies in poultry (Gallus gallus) and an in vitro digestion/Caco-2 model.
International journal for vitamin and nutrition research. Internationale Zeitschrift fur Vitamin- und Ernahrungsforschung. Journal international de vi, 2010Co-Authors: Elad Tako, Raymond P. GlahnAbstract:Iron-Biofortification of crops is a strategy that alleviates iron deficiency. The common Bean (Phaseolus vulgaris L.) is an attractive candidate for Biofortification. However, Beans are high in polyphenols that may inhiBit iron aBsorption. In vitro studies have shown that iron BioavailaBility from white Beans is higher than that from colored Beans. In this study, our oBjective was to determine if white Beans contain more BioavailaBle iron than red Beans and to determine if the in vitro oBservations of Bean-iron BioavailaBility would Be evident in an in vivo feeding trial. We compared iron BioavailaBility Between diets containing either white (Matterhorn) or red (Merlot) Beans, which differ in polyphenol content. One-week-old chicks (Gallus gallus) were divided into four groups: 1. "WB": 40% white-Bean diet; 2. "RB" :40% red-Bean diet; 3. "WB+Fe": 40% white-Bean diet; 4. "RB+Fe": 40% red-Bean diet (51, 47, 179, and 175 ppm iron, respectively). Diets 1 and 2 had no supplemental iron; whereas 125 µg/g iron was added to diets 3 and 4. For 8 weeks, hemogloBin, feed consumption, and Body weights were measured. Divalent metal transporter 1 (iron-uptake-transporter), <B>DuodenalB>-<B>CytochromeB>-B (iron reductase), and ferroportin (iron-exporter) expressions were higher (p
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Purified glycosaminoglycans from cooked haddock may enhance Fe uptake via endocytosis in a Caco-2 cell culture model.
Journal of food science, 2009Co-Authors: José Moisés Laparra, Raymond P. Glahn, Reyes Barberá, Amparo Alegría, Dennis D. MillerAbstract:This study aims to understand the enhancing effect of glycosaminoglycans (GAGs), such as chondroitin/dermatan structures, on Fe uptake to Caco-2 cells. High-sulfated GAGs were selectively purified from cooked haddock. An in vitro digestion/Caco-2 cell culture model was used to evaluate Fe uptake (cell ferritin formation) from a Fe(+3)-containing solution, and Fe(+3)/ascorBic acid (AA) and Fe(+3)/GAGs mixtures. Mitochondria (MTT test) and endosomal/lysosomal activities (neutral red uptake, NR), intracellular accumulation of reactive oxygen species, and GSH concentration were monitored as Biomarkers of the changes of cellular metaBolism. Changes in mRNA expression of Fe transporters, divalent metal transporter-1 (DMT1), and <B>DuodenalB> <B>CytochromeB>-B (DcytB) were also evaluated. The Fe uptake from Fe(+3)/GAGs mixture was up to 1.8-fold higher than from Fe(+3) alone. Both Fe(+3) alone and Fe(+3)/AA mixture produced highest increase in MTT conversion. In contrast, cell cultures exposed to the Fe(+3)/GAGs mixture exhiBited highest NR uptake values. All Fe-containing solutions tested caused a sharp intramitochondrial accumulation of reactive oxygen species. Cell cultures exposed to the Fe(+3)/GAGs mixture exhiBited a more preserved (By 8%) intracellular GSH concentration compared to cultures exposed to Fe(+3) or Fe(+3)/AA mixture. In addition to cell responses, the mRNA expression of Fe transporters may suggest that Fe could also Be internalized into cells By endocytosis in addition to via DMT1 in Fe(+3)/GAGs mixtures. These aspects need to Be confirmed in in vivo experiments to Better estaBlish nutritional interventional strategies.
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Dietary inulin affects the expression of intestinal enterocyte iron transporters, receptors and storage protein and alters the microBiota in the pig intestine.
The British journal of nutrition, 2007Co-Authors: Elad Tako, Raymond P. Glahn, Ross M. Welch, Xin Gen Lei, Koji Yasuda, Dennis D. MillerAbstract:Inulin, a linear B fructan, is present in a variety of plants including chicory root and wheat. It exhiBits preBiotic properties and has Been shown to enhance mineral aBsorption and increase Beneficial Bacteria in the colon. The aim of the present study was to assess the effect of dietary inulin on the gene expression of selected intestinal Fe transporters and Binding proteins. Anaemic piglets at age 5 weeks were allocated to a standard maize‐ soya diet (control) or the same diet supplemented with inulin at a level of 4%. After 6 weeks, the animals were killed and caecum contents and sections of the duodenum and colon were removed. Segments of the genes encoding for the pig divalent metal transporter 1 (DMT1) and <B>DuodenalB> <B>CytochromeB>-B reductase (DcytB) were isolated and sequenced. Semi-quantitative RT-PCR analyses were performed to evaluate the expression of DMT1, DcytB, ferroportin, ferritin, transferrin receptor (TfR) and mucin genes. DMT1, DcytB, ferroportin, ferritin and TfR mRNA levels in <B>DuodenalB> samples were significantly higher in the inulin group (P#0·05) compared with the control. In colon, DMT1, TfR and ferritin mRNA levels significantly increased in the inulin group. Additionally, the caecal content microflora was examined using 16S rDNA targeted proBes from Bacterial DNA. The LactoBacillus and BifidoBacterium populations were significantly increased in the inulin group (P#0·05) compared with the control group. These results indicate that dietary inulin might trigger an up regulation of genes encoding for Fe transporters in the enterocyte. The specific mechanism for this effect remains to Be elucidated. Inulin: Iron: Intestinal gene expression: MicroBiota
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Iron uptake By Caco-2 cells from NaFeEDTA and FeSO4: Effects of ascorBic acid, pH, and a Fe(II) chelating agent.
Journal of agricultural and food chemistry, 2006Co-Authors: Le Zhu, Raymond P. Glahn, Chi Kong Yeung, Dennis D. MillerAbstract:Sodium iron(III) ethylenediaminetetraacetate (NaFeEDTA) has consideraBle promise as an iron fortificant Because of its high BioavailaBility in foods containing iron aBsorption inhiBitors. In this study, uptakes of iron from NaFeEDTA, FeSO4, and FeCl3 By Caco-2 cells were compared in the aBsence or presence of ascorBic acid (AA), an iron aBsorption enhancer; at selected pH levels; and in the aBsence or presence of an iron aBsorption inhiBitor, Bathophenanthroline disulfonic acid (BPDS). Ferritin formation in the cells was used as the indicator of iron uptake. Uptake from all three Fe sources was similar in the aBsence of AA. Adding AA at a 5:1 molar excess as compared to Fe increased uptake By 5.4-, 5.1-, and 2.8-fold for FeSO4, FeCl3, and NaFeEDTA, respectively. The smaller effect of AA on uptake from NaFeEDTA may Be related to the higher soluBility of NaFeEDTA and/or the strong Binding affinity of EDTA for Fe3+, which may prevent AA and <B>DuodenalB> <B>CytochromeB> B from effectively reducing EDTA-Bound Fe. Uptak...
Elad Tako - One of the best experts on this subject based on the ideXlab platform.
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SoluBle Extracts from Chia Seed (Salvia hispanica L.) Affect Brush Border MemBrane Functionality, Morphology and Intestinal Bacterial Populations In Vivo (Gallus gallus).
Nutrients, 2019Co-Authors: Bárbara Pereira Da Silva, Hércia Stampini Duarte Martino, Nikolai Kolba, Jonathan J. Hart, Elad TakoAbstract:This study assessed and compared the effects of the intra-amniotic administration of various concentrations of soluBle extracts from chia seed (Salvia hispanica L.) on the Fe and Zn status, Brush Border memBrane functionality, intestinal morphology, and intestinal Bacterial populations, in vivo. The hypothesis was that chia seed soluBle extracts will affect the intestinal morphology, functionality and intestinal Bacterial populations. By using the Gallus gallus model and the intra-amniotic administration approach, seven treatment groups (non-injected, 18 Ω H2O, 40 mg/mL inulin, non-injected, 5 mg/mL, 10 mg/mL, 25 mg/mL and 50 mg/mL of chia seed soluBle extracts) were utilized. At hatch, the cecum, duodenum, liver, pectoral muscle and Blood samples were collected for assessment of the relative aBundance of the gut microflora, relative expression of Fe- and Zn-related genes and Brush Border memBrane functionality and morphology, relative expression of lipids-related genes, glycogen, and hemogloBin levels, respectively. This study demonstrated that the intra-amniotic administration of chia seed soluBle extracts increased (p < 0.05) the villus surface area, villus length, villus width and the numBer of goBlet cells. Further, we oBserved an increase (p < 0.05) in zinc transporter 1 (ZnT1) and <B>DuodenalB> <B>CytochromeB> B (DcytB) proteins gene expression. Our results suggest that the dietary consumption of chia seeds may improve intestinal health and functionality and may indirectly improve iron and zinc intestinal aBsorption.
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A Novel in Vivo Model for Assessing the Impact of Geophagic Earth on Iron Status
Nutrients, 2016Co-Authors: Gretchen L. Seim, Raymond P. Glahn, Elad Tako, Cedric Ahn, Sera L. YoungAbstract:The causes and consequences of geophagy, the craving and consumption of earth, remain enigmatic, despite its recognition as a Behavior with puBlic health implications. Iron deficiency has Been proposed as Both a cause and consequence of geophagy, But methodological limitations have precluded a decisive investigation into this relationship. Here we present a novel in vivo model for assessing the impact of geophagic earth on iron status: Gallus gallus (Broiler chicken). For four weeks, animals were gavaged daily with varying dosages of geophagic material or pure clay mineral. Differences in haemogloBin (HB) across treatment groups were assessed weekly and differences in liver ferritin, liver iron, and gene expression of the iron transporters divalent metal transporter 1 (DMT1), <B>DuodenalB> <B>CytochromeB> B (DcytB) and ferroportin were assessed at the end of the study. Minimal impact on iron status indicators was oBserved in all non-control groups, suggesting dosing of geophagic materials may need refining in future studies. However, this model shows clear advantages over prior methods used Both in vitro and in humans, and represents an important step in explaining the puBlic health impact of geophagy on iron status.
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White Beans provide more BioavailaBle iron than red Beans: studies in poultry (Gallus gallus) and an in vitro digestion/Caco-2 model.
International journal for vitamin and nutrition research. Internationale Zeitschrift fur Vitamin- und Ernahrungsforschung. Journal international de vi, 2010Co-Authors: Elad Tako, Raymond P. GlahnAbstract:Iron-Biofortification of crops is a strategy that alleviates iron deficiency. The common Bean (Phaseolus vulgaris L.) is an attractive candidate for Biofortification. However, Beans are high in polyphenols that may inhiBit iron aBsorption. In vitro studies have shown that iron BioavailaBility from white Beans is higher than that from colored Beans. In this study, our oBjective was to determine if white Beans contain more BioavailaBle iron than red Beans and to determine if the in vitro oBservations of Bean-iron BioavailaBility would Be evident in an in vivo feeding trial. We compared iron BioavailaBility Between diets containing either white (Matterhorn) or red (Merlot) Beans, which differ in polyphenol content. One-week-old chicks (Gallus gallus) were divided into four groups: 1. "WB": 40% white-Bean diet; 2. "RB" :40% red-Bean diet; 3. "WB+Fe": 40% white-Bean diet; 4. "RB+Fe": 40% red-Bean diet (51, 47, 179, and 175 ppm iron, respectively). Diets 1 and 2 had no supplemental iron; whereas 125 µg/g iron was added to diets 3 and 4. For 8 weeks, hemogloBin, feed consumption, and Body weights were measured. Divalent metal transporter 1 (iron-uptake-transporter), <B>DuodenalB>-<B>CytochromeB>-B (iron reductase), and ferroportin (iron-exporter) expressions were higher (p
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Dietary inulin affects the expression of intestinal enterocyte iron transporters, receptors and storage protein and alters the microBiota in the pig intestine.
The British journal of nutrition, 2007Co-Authors: Elad Tako, Raymond P. Glahn, Ross M. Welch, Xin Gen Lei, Koji Yasuda, Dennis D. MillerAbstract:Inulin, a linear B fructan, is present in a variety of plants including chicory root and wheat. It exhiBits preBiotic properties and has Been shown to enhance mineral aBsorption and increase Beneficial Bacteria in the colon. The aim of the present study was to assess the effect of dietary inulin on the gene expression of selected intestinal Fe transporters and Binding proteins. Anaemic piglets at age 5 weeks were allocated to a standard maize‐ soya diet (control) or the same diet supplemented with inulin at a level of 4%. After 6 weeks, the animals were killed and caecum contents and sections of the duodenum and colon were removed. Segments of the genes encoding for the pig divalent metal transporter 1 (DMT1) and <B>DuodenalB> <B>CytochromeB>-B reductase (DcytB) were isolated and sequenced. Semi-quantitative RT-PCR analyses were performed to evaluate the expression of DMT1, DcytB, ferroportin, ferritin, transferrin receptor (TfR) and mucin genes. DMT1, DcytB, ferroportin, ferritin and TfR mRNA levels in <B>DuodenalB> samples were significantly higher in the inulin group (P#0·05) compared with the control. In colon, DMT1, TfR and ferritin mRNA levels significantly increased in the inulin group. Additionally, the caecal content microflora was examined using 16S rDNA targeted proBes from Bacterial DNA. The LactoBacillus and BifidoBacterium populations were significantly increased in the inulin group (P#0·05) compared with the control group. These results indicate that dietary inulin might trigger an up regulation of genes encoding for Fe transporters in the enterocyte. The specific mechanism for this effect remains to Be elucidated. Inulin: Iron: Intestinal gene expression: MicroBiota
Gladys O. Latunde-dada - One of the best experts on this subject based on the ideXlab platform.
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<B>DuodenalB> <B>CytochromeB> B (CyBrd1) ferric reductase functional studies in cells
Metallomics, 2017Co-Authors: Francisco Schlottmann, Mayra Vera-aviles, Gladys O. Latunde-dadaAbstract:Dietary non-heme ferric iron is reduced By the ferric reductase enzyme, <B>DuodenalB> <B>CytochromeB> B (DcytB), Before aBsorption By the divalent metal transporter 1 (DMT1). A single nucleotide polymorphism (SNP rs10455 mutant) that is located in the last exon of the DcytB gene was reported in C282Y haemochromatosis HFE suBjects. The present work therefore investigated the phenotype of this mutant DcytB in Chinese hamster ovary (CHO) cells. These cultured cells were transfected with either wild type (WT) or the SNP vector plasmids of DcytB. Ferric reductase assays were performed in DcytB transgenic CHO cells using the ferrozine spectrophometric assay protocol. The DcytB SNP rs10455 showed a gain-of-function capaBility since ferric reductase activity increased significantly (p < 0.01) in the transgenic cells. Varying ferric reductase activity was found when CHO cells were pretreated with modulators of DcytB protein expression. Although ferric reductase in endogenous CHO cells increased with deferoxamine or CoCl2, iron loading with ferric ammonium citrate (FAC) had the opposite effect. Taken together, the study reveals a gain-of-function phenotype for DcytB rs10455 mutation that could Be a putative modifier of colorectal cancer risk, with attendant variaBility in penetrance among human HFE C282Y homozygotes.
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<B>DuodenalB> <B>CytochromeB> B (CyBrd1) ferric reductase functional studies in cells
Metallomics, 2017Co-Authors: Francisco Schlottmann, Mayra Vera-aviles, Gladys O. Latunde-dadaAbstract:Dietary non-heme ferric iron is reduced By the ferric reductase enzyme, <B>DuodenalB> <B>CytochromeB> B (DcytB), Before aBsorption By the divalent metal transporter 1 (DMT1). A single nucleotide polymorphism (SNP rs10455 mutant) that is located in the last exon of the DcytB gene was reported in C282Y haemochromatosis HFE suBjects. The present work therefore investigated the phenotype of this mutant DcytB in Chinese hamster ovary (CHO) cells. These cultured cells were transfected with either wild type (WT) or the SNP vector plasmids of DcytB. Ferric reductase assays were performed in DcytB transgenic CHO cells using the ferrozine spectrophometric assay protocol. The DcytB SNP rs10455 showed a gain-of-function capaBility since ferric reductase activity increased significantly (p < 0.01) in the transgenic cells. Varying ferric reductase activity was found when CHO cells were pretreated with modulators of DcytB protein expression. Although ferric reductase in endogenous CHO cells increased with deferoxamine or CoCl2, iron loading with ferric ammonium citrate (FAC) had the opposite effect. Taken together, the study reveals a gain-of-function phenotype for DcytB rs10455 mutation that could Be a putative modifier of colorectal cancer risk, with attendant variaBility in penetrance among human HFE C282Y homozygotes.
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A Nanoparticulate Ferritin-Core Mimetic Is Well Taken Up By HuTu 80 <B>DuodenalB> Cells and Its ABsorption in Mice Is Regulated By Body Iron
The Journal of nutrition, 2014Co-Authors: Gladys O. Latunde-dada, Robert J. Simpson, Dora I. A. Pereira, Bethan Tempest, Hibah Ilyas, Angela C. Flynn, Mohamad F. Aslam, Jonathan J. PowellAbstract:Background: Iron (Fe) deficiency anemia remains the largest nutritional deficiency disorder worldwide. How the gut acquires iron from nano Fe(III), especially at the apical surface, is incompletely understood. OBjective: We developed a novel Fe supplement consisting of nanoparticulate tartrate-modified Fe(III) poly oxo-hydroxide [here termed nano Fe(III)], which mimics the Fe oxide core of ferritin and effectively treats iron deficiency anemia in rats. Methods: We determined transfer to the systemic circulation of nano Fe(III) in iron-deficient and iron-sufficient outBread Swiss mouse strain (CD1) mice with use of 59Fe-laBeled material. Iron deficiency was induced Before starting the Fe-supplementation period through reduction of Fe concentrations in the rodent diet. A control group of iron-sufficient mice were fed a diet with adequate Fe concentrations throughout the study. Furthermore, we conducted a hemogloBin repletion study in which iron-deficient CD1 mice were fed for 7 d a diet supplemented with ferrous sulfate (FeSO4) or nano Fe(III). Finally, we further proBed the mechanism of cellular acquisition of nano Fe(III) By assessing ferritin formation, as a measure of Fe uptake and utilization, in HuTu 80 <B>DuodenalB> cancer cells with targeted inhiBition of divalent metal transporter 1 (DMT1) and <B>DuodenalB> <B>CytochromeB> B (DCYTB) Before exposure to the supplemented iron sources. Differences in gene expression were assessed By quantitative polymerase chain reaction. Results: ABsorption (means ± SEMs) of nano Fe(III) was significantly increased in iron-deficient mice (58 ± 19%) compared to iron-sufficient mice (18 ± 17%) (P = 0.0001). Supplementation of the diet with nano Fe(III) or FeSO4 significantly increased hemogloBin concentrations in iron-deficient mice (170 ± 20 g/L, P = 0.01 and 180 ± 20 g/L, P = 0.002, respectively). Hepatic hepcidin mRNA expression reflected the nonheme-iron concentrations of the liver and was also comparaBle for Both nano Fe(III)– and FeSO4-supplemented groups, as were iron concentrations in the spleen and duodenum. Silencing of the solute carrier family 11 (proton-coupled divalent metal ion transporter), memBer 2 (Slc11a2) gene (DMT1) significantly inhiBited ferritin formation from FeSO4 (P = 0.005) But had no effect on uptake and utilization of nano Fe(III). InhiBiting DCYTB with an antiBody also had no effect on uptake and utilization of nano Fe(III) But significantly inhiBited ferritin formation from ferric nitrilotriacetate chelate (Fe-NTA) (P = 0.04). Similarly, cellular ferritin formation from nano Fe(III) was unaffected By the Fe(II) chelator ferrozine, which significantly inhiBited uptake and utilization from FeSO4 (P = 0.009) and Fe-NTA (P = 0.005). Conclusions: Our data strongly support direct nano Fe(III) uptake By enterocytes as an efficient mechanism of dietary iron acquisition, which may complement the known Fe(II)/DMT1 uptake pathway.
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Modulation of DcytB (CyBrd 1) expression and function By iron, dehydroascorBate and Hif-2α in cultured cells.
Biochimica et biophysica acta, 2013Co-Authors: Xiaomin Luo, Melanie Hill, Anna D. Johnson, Gladys O. Latunde-dadaAbstract:ABstract Background <B>DuodenalB> <B>CytochromeB> B (DcytB) is a mammalian plasma ferric reductase enzyme that catalyses the reduction of ferric to ferrous ion in the process of iron aBsorption. The current study investigates the relationship Between DcytB, iron, dehydroascorBate (DHA) and Hif-2α in cultured cell lines. Methods DcytB and Hif-2α protein expression was analysed By Western Blot technique while gene regulation was determined By quantitative PCR. Functional analyses were carried out By ferric reductase and 59Fe uptake assays. Results Iron and dehydroascorBic acid treatment of cells inhiBited DcytB mRNA and protein expression. Desferrioxamine also enhanced DcytB mRNA level after cells were treated overnight. DcytB knockdown in HuTu cells resulted in reduced mRNA expression and lowered reductase activity. Preloading cells with DHA (to enhance intracellular ascorBate levels) did not stimulate reductase activity fully in DcytB-silenced cells, implying a DcytB-dependence of ascorBate-mediated ferrireduction. Moreover, Hif-2α knockdown in HuTu cells led to a reduction in reductase activity and iron uptake. Conclusions Taken together, this study shows the functional regulation of DcytB reductase activity By DHA and Hif-2α. General significance DcytB is a plasma memBrane protein that accepts electrons intracellularly from DHA/ascorBic acid for ferrireduction at the apical surface of cultured cells and enterocytes.
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<B>DuodenalB> Reductase Activity and Spleen Iron Stores Are Reduced and Erythropoiesis Is ABnormal in DcytB Knockout Mice Exposed to Hypoxic Conditions
The Journal of nutrition, 2012Co-Authors: Jeehyea Choi, Gladys O. Latunde-dada, Robert J. Simpson, Patarabutr Masaratana, Matthew Arno, Andrew T. MckieAbstract:<B>DuodenalB> <B>CytochromeB> B (DcytB, CyBrd1) is a ferric reductase localized in the duodenum that is highly upregulated in circumstances of increased iron aBsorption. To address the contriBution of DcytB to total <B>DuodenalB> ferric reductase activity as well as its wider role in iron metaBolism, we first measured <B>DuodenalB> ferric reductase activity in wild-type (WT) and DcytB knockout (DcytB(-/-)) mice under 3 conditions known to induce gut ferric reductase: dietary iron deficiency, hypoxia, and pregnancy. DcytB(-/-) and WT mice were randomly assigned to control (iron deficiency experiment, 48 mg/kg dietary iron; hypoxia experiment, normal atmospheric pressure; pregnancy experiment, nonpregnant animals) or treatment (iron deficiency experiment, 2-3 mg/kg dietary iron; hypoxia experiment, 53.3 kPa pressure; pregnancy experiment, d 20 of pregnancy) groups and <B>DuodenalB> reductase activity measured. We found no induction of ferric reductase activity in DcytB(-/-) mice under any of these conditions, indicating there are no other induciBle ferric reductases present in the duodenum. To test whether DcytB was required for iron aBsorption in conditions with increased erythropoietic demand, we also measured tissue nonheme iron levels and hematological indices in WT and DcytB(-/-) mice exposed to hypoxia. There was no evidence of gross alterations in iron aBsorption, hemogloBin, or total liver nonheme iron in DcytB(-/-) mice exposed to hypoxia compared with WT mice. However, spleen nonheme iron was significantly less (6.7 ± 1.0 vs. 12.7 ± 0.9 nmol · mg tissue(-1); P < 0.01, n = 7-8) in hypoxic DcytB(-/-) compared with hypoxic WT mice and there was evidence of impaired reticulocyte hemogloBinization with a lower reticulocyte mean corpuscular hemogloBin (276 ± 1 vs. 283 ± 2 g · L(-1); P < 0.05, n = 7-8) in normoxic DcytB(-/-) compared with normoxic WT mice. We therefore conclude that DCYTB is the primary iron-regulated <B>DuodenalB> ferric reductase in the gut and that DcytB is necessary for optimal iron metaBolism.
