Iron Transporters and Iron Homeostasis

Whole-body iron homeostasis can be largely understood by considering the iron metabolism in four main cell types: the enterocyte, the erythroid precursor cell, the hepatocyte, and the reticuloendothelial macrophage. These cell types are involved in iron absorption, iron incorporation into hemoglobin, iron storage, and iron recycling, respectively. The aim of this review is to summarize current knowledge of iron metabolism in these cells. Emphasis is placed on iron transporters and molecular mechanisms that direct the movement of iron (and heme) into, within, and out of cells. The role of hepcidin in controlling the flow of iron among various cell types, along with the main drivers of hepcidin expression, will also be discussed.