Ganz Tomas
Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA 90095-1690, USA.
Best Pract Res Clin Haematol. 2005 Jun;18(2):171-82. doi: 10.1016/j.beha.2004.08.020.
Hepcidin is a recently discovered peptide made in the liver, distributed in plasma and excreted in urine. This peptide hormone is the homeostatic regulator of intestinal iron absorption, iron recycling by macrophages, and iron mobilization from hepatic stores. Hepcidin acts by inhibiting the efflux of iron through ferroportin, the sole known iron exporter of enterocytes, macrophages and hepatocytes. As befits an iron-regulatory hormone, hepcidin synthesis is increased by iron loading and decreased by anemia and hypoxia. Hepcidin is markedly induced during infections and inflammation, causing iron to be sequestered in macrophages, hepatocytes and enterocytes. The resulting decrease in plasma iron levels eventually contributes to the anemia associated with infection and inflammation. These alterations in iron metabolism probably have a role in host defense by limiting the availability of iron to invading microorganisms. At the opposite extreme, early studies indicate that hepcidin deficiency--due to the dysregulation of its synthesis or mutations in the hepcidin gene itself--is the immediate cause of most forms of hemochromatosis.
铁调素是一种最近发现的由肝脏产生的肽，分布于血浆中并经尿液排泄。这种肽激素是肠道铁吸收、巨噬细胞铁循环以及肝脏铁储备中铁动员的稳态调节因子。铁调素通过抑制铁转运蛋白介导的铁外流发挥作用，铁转运蛋白是已知的肠上皮细胞、巨噬细胞和肝细胞唯一的铁输出蛋白。作为一种铁调节激素，铁调素的合成在铁负荷增加时增加，而在贫血和缺氧时减少。在感染和炎症期间，铁调素会显著诱导产生，导致铁被隔离在巨噬细胞、肝细胞和肠上皮细胞中。血浆铁水平的降低最终导致了与感染和炎症相关的贫血。铁代谢的这些改变可能通过限制入侵微生物可利用的铁来在宿主防御中发挥作用。相反，早期研究表明，由于铁调素合成失调或铁调素基因本身发生突变导致的铁调素缺乏是大多数形式的血色素沉着症的直接原因。
