Molecular mechanism of the absorption of essential trace metals in intestinal epithelial cells

Abstract

Iron (Fe), zinc (Zn) and copper (Cu) are essential trace metals for our lives. Recent advances in understanding of the molecules involved in their metabolism have allowed for elucidation of the mechanism of their absorption in the intestine. Fe-, Zn- and Cu-specific transporters operate in enterocytes. Transporters that locate at the apical surface mediates uptake of Fe, Zn and Cu in the diet into enterocytes across the apical membrane, while other transporters are involved in efflux of them from enterocytes across the basal membrane into circulation, although intracellular trafficking of these metals between apical and basal sides of the enterocytes has yet to be defined. Herein, we briefly review the molecular mechanism, focusing on the key players involved. Moreover, we discuss the possibility that dietary components may increase the absorption efficiency of Fe and Zn through transporters, because recent studies have indicated that a number of dietary components affect their bioavailability.