Hemojuvelin: a supposed role in iron metabolism one year after its discovery
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The discovery of hemojuvelin and its association with juvenile hemochromatosis are important not only for the diagnostics of this rare severe disease but also for the understanding of the complex mechanism of iron metabolism regulation. Currently, the physiological role of hemojuvelin is obscure. Recent experimental and clinical studies indicate that hemojuvelin will probably be a regulator of hepcidin, similar to HFE and transferrin receptor 2. However, in contrast to transferrin receptor 2, which is relevant in the hepcidin response to changes in transferrin saturation, HFE and especially hemojuvelin seem to be involved in the inflammation-induced hepcidin expression. Hepcidin, generally accepted as a hormone targeting enterocytes and macrophages, decreases iron absorption from the intestinal lumen and iron release from phagocytes. This mechanism explains the central role of hepcidin and, indirectly, its regulator, hemojuvelin, in the pathogenesis of hemochromatosis but also in anemia of chronic disease. Further basic and clinical research is needed to uncover the details of hemojuvelin pathophysiology required for potential pharmacological interventions.
KeywordsHemojuvelin Hepcidin HFE Juvenile hemochromatosis Iron metabolism
The author would like to thank Assoc. Prof. Ĺubomír Tomáška, Ph.D., for the stimulus to write this article and for his critical reading of the manuscript. The anonymous reviewers and their comments should be acknowledged. The author is supported by grants 116/2004 and 117/2004 from the Comenius University and by the Agency for Science and Technology grant APVT-20-003-104.
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