Abstract
Iron (Fe), copper (Cu), and zinc (Zn) fulfill various essential biological functions and are vital for all living organisms. They play important roles in oxygen transport, cell growth and differentiation, neurotransmitter synthesis, myelination, and synaptic transmission. Because of their role in many critical functions, they are commonly used in food fortification and supplementation strategies globally. To determine the involvement of divalent metal transporter 1 (DMT1) and human copper transporter 1 (hCTR1) on Fe, Cu, and Zn uptake, Caco-2 cells were transfected with four different shRNA plasmids to selectively inhibit DMT1 or hCTR1 transporter expression. Fe and Cu uptake and total Zn content measurements were performed in shRNA-DMT1 and shRNA-hCTR1 cells. Both shRNA-DMT1 and shRNA-hCTR1 cells had lower apical Fe uptake (a decrease of 51% and 41%, respectively), Cu uptake (a decrease of 25.8% and 38.5%, respectively), and Zn content (a decrease of 23.1% and 22.7%, respectively) compared to control cells. These results confirm that DMT1 is involved in active transport of Fe, Cu, and Zn although Zn showed a different relative capacity. These results also show that hCTR1 is able to transport Fe and Zn.
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Crichton R, Boelaert JR, Braun V et al (2001) The importance of iron for biological systems. In: Crichton R (ed) Inorganic biochemistry of iron metabolism: from molecular mechanisms to clinical consequences, 2nd edn. Wiley, Chichester
McCall KA, Huang C, Fierke CA (2000) Function and mechanism of zinc of zinc metalloenazymes. J Nutr 130:1437S–1446S
Institute of Medicine, Food and Nutrition Board (2002) Dietary reference intakes for vitamin A, vitamin K, arsenic, boron, chromium, copper, iodine, iron, manganese, molybdenum, nickel, silicon, vanadium, and zinc. National Academy Press, Washington, pp 224–257
Ruz M (2003) Zinc properties and determination. In: Caballero B, Trugo L, Finglas P (eds) Encyclopedia of food sciences and nutrition. Academic, London, pp 6267–6272
López de Romaña D, Olivares M, Uauy R, Araya M (2011) Risks and benefits of copper in light of new insights of copper homeostasis. J Trace Elem Med Biol 25:3–13
Gunshin H, Mackenzie B, Berger U et al (1997) Cloning and characterization of a mammalian proton-coupled metal-iron transporter. Nature 388:482–488
Arredondo M, Muñoz P, Mura C et al (2003) DMT1, a physiologically relevant apical Cu+1 transporter of intestinal cells. Am J Physiol 284:C1525–C1530
Zhou B, Gitschier A (1997) hCTR1: a human gene for copper uptake identified by complementation in yeast. Proc Natl Acad Sci 94:7481–7486
Foster M, Samman S (2010) Zinc and redox signaling: perturbations associated with cardiovascular disease and diabetes mellitus. Antioxid Redox Signal 13:1549–1573
Ramakrishnan U (2002) Prevalence of micronutrient malnutrition worldwide. Nutr Rev 60(5):S46–S52
Olivares M, Walter T, Hertrampf E (1999) Anaemia and iron deficiency disease in children. Brit Med Bull 55:534–548
Ruz M, Cavan KR, Bettger WJ et al (1991) Development of a dietary model for the study of mild zinc deficiency in humans and evaluation of some biochemical and functional indices of zinc status. Am J Clin Nutr 53:1295–1203
Ruz M, Cavan KR, Bettger WJ et al (1992) Erythrocytes, erythrocyte membranes, neuthrophils, an platelets as biopsy materials for the assessment of zinc status in humans. Br J Nutr 68:515–527
International Zinc Nutrition Consultative Group (IZiNCG), Brown KH, Rivera JA et al (2004) International Zinc Nutrition Consultative Group (IZiNCG) technical document #1. Assessment of the risk of zinc deficiency in populations and options for its control. Food Nutr Bull 25:S99–S203
Benoist B, Darnton-Hil I, Davidsson L, Fontaine O, Hotz C (2007) Conclusions of the Joint WHO/UNICEF/IAEA/IZiNCG Interagency Meeting on Zinc Status Indicators. Food Nutr Bull 28:S480–S484
INACG (1977) Guidelines for the eradication of iron deficiency anemia, a report of the International Nutritional Anemia Consultative Group. INACG, Washington, pp 1–29
Olivares M, Pizarro F, Ruz M (2007) Zinc inhibits nonheme iron bioavailability in humans. Biol Trace Elem Res 117:7–14
Yamaji S, Tennant J, Tandy S et al (2001) Zinc regulates the function and expression of the iron transporters DMT1and IREG1 in human intestinal Caco-2 cells. FEBS Lett 507:137–141
Arredondo M, Martínez R, Núñez MT, Ruz M, Olivares M (2006) Inhibition of iron and copper uptake by iron, copper and zinc. Biol Res 39:95–102
Olivares M, Pizarro F, López de Romaña D et al (2010) Acute copper supplementation does not inhibit non-heme iron bioavalability in humans. Biol Trace Elem Res 136:180–186
Tallkvist J, Bowlus CL, Lönnerdal B (2000) Functional and molecular responses of human intestinal Caco-2 cells to iron treatment. Am J Clin Nutr 72:770–775
Tandy S, Williams M, Leggett A et al (2000) Nramp2 expression is associated with pH-dependent iron uptake across the apical membrane of human intestinal Caco-2 cells. J Biol Chem 275:1023–1029
Kordas K, Stoltzfus RJ (2004) New evidence of iron and zinc interplay at the enterocyte and neural tissues. J Nutr 134:1295–1298
Wang K, Zhou B, Kuo YM, Zemansky J, Gitschier J (2002) A novel member of a zinc transporter family is defective in acrodermatitis enteropathica. Am J Hum Genet 71:66–73
Pfaffl M (2001) A new mathematical model for relative quantification in real-time RT-PCR. Nucleic Acids Res 29:e45
Lowry OH, Rosebrough NJ, Farr AL et al (1951) Protein measurement with the Folin phenol reagent. J Biol Chem 193:265–275
Zimnicka A, Maryon E, Kaplan J (2007) Human copper transportes hCTR1 mediates basolateral uptake of copper into enterocytes. Implications for copper homeostasis. J Biol Chem 282:26471–26480
Iyengar V, Pullakhandam R, Nair KM (2009) Iron-zinc interaction during uptake in human intestinal Caco-2 cell line: kinetic analyses and possible mechanism. Indian J Biochem Biophys 46(4):299–306
Liuzzi JP, Cousins R (2004) Mammalian zinc transporters. Annu Rev Nutr 24:151–172
Qin Y, Dittmer PJ, Park JG, Jansen KB, Palmer AE (2011) Measuring steady-state and dynamic endoplasmic reticulum and Golgi Zn2þ with genetically encoded sensors. PNAS 108:7351–7356
Garrick MD, Singleton ST, Vargas F et al (2006) DMT1: which metals does it transport? Biol Res 39:79–85
Liuzzi JP, Aydemir F, Nam H, Knutson M, Cousins R (2006) Zip14 (Slc39a14) mediates non-transferrin-bound iron uptake into cells. Proc Natl Acad Sci U S A 103(37):13612–13617
Acknowledgments
This work was supported by Grant 1070665 from Fondo Nacional de Ciencia y Tecnología (FONDECYT), Chile to M. Olivares. We thank Katharine Jones for her assistance in reviewing the English in this manuscript.
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This work was supported by Fondo Nacional de Ciencia y Tecnología grant #1070665.
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Espinoza, A., Le Blanc, S., Olivares, M. et al. Iron, Copper, and Zinc Transport: Inhibition of Divalent Metal Transporter 1 (DMT1) and Human Copper Transporter 1 (hCTR1) by shRNA. Biol Trace Elem Res 146, 281–286 (2012). https://doi.org/10.1007/s12011-011-9243-2
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DOI: https://doi.org/10.1007/s12011-011-9243-2