Abstract
Iron is an essential trace element for human beings, but at the same time, it is toxic for us to generate free radicals because of its high reactivity to molecular oxygen. Therefore, iron metabolism is tightly regulated. Recently, hepcidin, a peptide hormone secreted by hepatocytes in response to iron overload and inflammation, has been identified to be a predominant negative regulator of iron absorption in the duodenum and iron release from tissue macrophages. The discovery of hepcidin unexpectedly revealed the link between iron metabolism and host defense. Here we describe recent advance in our understanding on the regulation of iron metabolism, including our findings and discuss its relationship to various diseases.