Abstract
Introduction: Heme Fe is the main source of Fe in developed countries, because it has a better absorption than inorganic Fe. In the cell, heme-Fe is degradated to free Fe, Co and biliverdin for the microsomal enzyme heme oxygenase (HO). The role of HO1 in the intracellular Fe metabolism and heme-Fe uptake mechanisms by the cell it is unknown.
Objective: To study the intracellular distribution of HO1 and its relationship with the heme-Fe uptake mechanisms in the enterocyte.
Methods: Caco-2 cells were incubated with heme-Fe55 in the presence of inhibitors of endocytosis and intracellular traffic. HO1 intracellular localization was studied by membrane biotinylation and confocal microscopy.
Results: HO1 is localized mainly in the apical membrane of the enterocyte and co-localized with the glucose transporter Glut1. However, a small fraction is localized in the basolateral membrane and co-localized with the transferrin receptor. Heme-Fe uptake increased en the presence of cytochalasin D, metil-β-cyclodextrine, nocodazole and phenylarsine oxide.
Conclusions: Heme-Fe uptake process involved the participation of active HO1 in the apical membrane and proteins and microfilaments associated to the plasma membrane.
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Supported by FONDECYT 1030633 Chile.
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Arredondo, M., Flores, S., Mendiburo, M. et al. Heme-Fe Uptake Involves the Participation of Heme Oxygenase and Microfilaments Associated to the Apical Membrane: P045. Pediatr Res 60, 638 (2006). https://doi.org/10.1203/00006450-200611000-00038
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DOI: https://doi.org/10.1203/00006450-200611000-00038