What regulates iron in the blood?
The mechanisms regulating systemic iron homeostasis are largely centred on the liver and involve two molecules, hepcidin and ferroportin, that work together to regulate the flow of iron from cells into the systemic circulation.
How the liver regulates iron uptake by enterocytes?
The liver-derived peptide hepcidin plays a critical role in the regulation of body iron intake and distribution by binding to plasma membrane FPN1 on enterocytes, macrophages, and most body cells and facilitating its internalization and degradation. Hepcidin, in turn, is regulated by body iron demand.
What is ferritin responsible for?
Ferritin, an iron storage protein, is the primary iron storage mechanism and is critical to iron homeostasis. Ferritin makes iron available for critical cellular processes while protecting lipids, DNA, and proteins from the potentially toxic effects of iron.
What controls iron absorption in the body?
At the whole-body level, dietary iron absorption and iron export from the tissues into the plasma are regulated by the liver-derived peptide hepcidin.
How and where are iron levels regulated in the body?
Human iron homeostasis is regulated at two different levels. Systemic iron levels are balanced by the controlled absorption of dietary iron by enterocytes, the cells that line the interior of the intestines, and the uncontrolled loss of iron from epithelial sloughing, sweat, injuries and blood loss.
In what form is iron absorbed by enterocytes in the intestine?
Iron absorption is predominantly regulated at the basolateral surface of the duodenal enterocyte by control of iron export through ferroportin into plasma. Iron is take up into the duodenal enterocyte on the apical membrane via DMT1 and is stored or exported during its life span of a few days (Fig. 3).
What is difference between ferritin and iron?
What is the difference between iron and ferritin? Iron is an important mineral present in red blood cells that carries oxygen to cells in the body. Ferritin on the other hand is a protein that stores iron and releases iron when the body needs it.
How does transferrin transport iron in the blood?
Transferrin is the major iron transport protein (transports iron through blood). Fe3+ is the form of iron that binds to transferrin, so the Fe2+ transported through ferroportin must be oxidized to Fe3+. There are 2 copper-containing proteins that catalyze this oxidation of Fe2+: hephaestin and ceruloplasmin.
Which is the key regulator of iron metabolism?
Blood (2003) 102 (3): 783–788. A related article has been published: Unlocking the mysteries of iron homeostasis and of the anemia of chronic disease: is hepcidin the key? Tomas Ganz; Hepcidin, a key regulator of iron metabolism and mediator of anemia of inflammation.
How is the fate of dietary iron determined?
Because the lifespan of enterocytes is a few days, the fate of dietary iron taken up by enterocytes would be determined by the regulated basolateral iron transporter (s): either the absorbed iron was allowed to enter blood circulation, or it would be returned into the intestinal lumen with the dying enterocytes, as they shed into the fecal stream.
How does ferroportin enable efflux of iron from enterocytes?
Enterocytes acquire iron only through DMT-1 and the DMT-1 transcript has a 3’ IRE, similar to that of TfR. Ferroportin on the other hand has a 5’ IRE, thus enabling efflux of excess iron from enterocytes and macrophages.
How are enterocytes involved in the immune response?
Enterocytes sample bacterial and other foreign antigens within the lumen and present them to cells of the mucosal immune system thus directing immune responses to potentially harmful antigens. Enterocytes have been shown to possess maybe several processing and presentation pathways for antigens.
