Iron is an important element for life; however, intracellular labile iron overload can lead to the generation of reactive oxygen species and cellular damage. Although iron is mainly utilized for heme synthesis and is incorporated into hemoglobin, body iron status is often implicated in the pathogenesis of cardiovascular diseases. In a cell, iron is used for basic processes such as cell growth, maintenance, and repair. Thus, iron is considered to be involved in the pathogenesis of arteriosclerosis. In fact, clinical and experimental studies have shown an association between iron and arteriosclerosis. These data suggest the crosstalk between iron and arteriosclerosis. However, iron metabolism in arteriosclerosis is often complicated, and the systemic and cellular mechanisms of iron homeostasis in arteriosclerosis remain completely unsolved. Thus, in this review, we aimed to examine the role of iron in arteriosclerosis.of arteriosclerosis and atherosclerosis, respectively [4][5][6][7] . Iron metabolism in arteriosclerosis and atherosclerosis is often complicated, and the systemic and cellular mechanisms of iron homeostasis in arteriosclerosis and atherosclerosis remain to be largely unknown. Thus, in this review, we focus on the role of iron in arteriosclerosis and atherosclerosis.
Systemic Iron TransportMore than 70% of body iron exists as heme within hemoglobin. Further, 20% of body iron is stored in the liver and 5% in macrophages. Most of the iron is recycled as erythrocytes in the body. Macrophages phagocytize senescent erythrocytes, degrade hemoglobin-derived heme, and export to the circulation. The released iron is mainly used in hematopoiesis in the bone marrow, while excess body iron is stored in the liver 8) .Systemic iron homeostasis is tightly regulated by the peptide hormone hepcidin in the liver and maintained through dietary absorption in the duodenum. In the duodenum, dietary iron (Fe 3+ ) is transported into enterocyte via apical membrane iron Copyright©2021 Japan Atherosclerosis Society This article is distributed under the terms of the latest version of CC BY-NC-SA defined by the Creative Commons Attribution License.