Lane Darius J R, Bae Dong-Hun, Merlot Angelica M, Sahni Sumit, Richardson Des R
Molecular Pharmacology and Pathology Program, Department of Pathology and Bosch Institute, University of Sydney, Sydney, NSW 2006, Australia.
Nutrients. 2015 Mar 31;7(4):2274-96. doi: 10.3390/nu7042274.
Iron and ascorbate are vital cellular constituents in mammalian systems. The bulk-requirement for iron is during erythropoiesis leading to the generation of hemoglobin-containing erythrocytes. Additionally; both iron and ascorbate are required as co-factors in numerous metabolic reactions. Iron homeostasis is controlled at the level of uptake; rather than excretion. Accumulating evidence strongly suggests that in addition to the known ability of dietary ascorbate to enhance non-heme iron absorption in the gut; ascorbate regulates iron homeostasis. The involvement of ascorbate in dietary iron absorption extends beyond the direct chemical reduction of non-heme iron by dietary ascorbate. Among other activities; intra-enterocyte ascorbate appears to be involved in the provision of electrons to a family of trans-membrane redox enzymes; namely those of the cytochrome b561 class. These hemoproteins oxidize a pool of ascorbate on one side of the membrane in order to reduce an electron acceptor (e.g., non-heme iron) on the opposite side of the membrane. One member of this family; duodenal cytochrome b (DCYTB); may play an important role in ascorbate-dependent reduction of non-heme iron in the gut prior to uptake by ferrous-iron transporters. This review discusses the emerging relationship between cellular iron homeostasis; the emergent "IRP1-HIF2α axis"; DCYTB and ascorbate in relation to iron metabolism.
铁和抗坏血酸是哺乳动物系统中至关重要的细胞成分。铁的大量需求发生在红细胞生成过程中,这会导致含血红蛋白的红细胞生成。此外,铁和抗坏血酸在众多代谢反应中作为辅助因子发挥作用。铁稳态在吸收水平上受到控制,而非排泄。越来越多的证据有力地表明,除了膳食抗坏血酸能增强肠道中非血红素铁的吸收这一已知能力外,抗坏血酸还调节铁稳态。抗坏血酸在膳食铁吸收中的作用不仅限于膳食抗坏血酸对非血红素铁的直接化学还原。在其他活动中,肠细胞内的抗坏血酸似乎参与向一类跨膜氧化还原酶(即细胞色素b561类酶)提供电子。这些血红蛋白在膜的一侧氧化抗坏血酸池,以便在膜的另一侧还原电子受体(如非血红素铁)。该家族的一个成员,十二指肠细胞色素b(DCYTB),可能在肠道中非血红素铁被亚铁转运蛋白摄取之前,在抗坏血酸依赖性还原过程中发挥重要作用。本综述讨论了细胞铁稳态、新兴的“IRP1-HIF2α轴”、DCYTB和抗坏血酸在铁代谢方面的新出现的关系。