Expression of Rgmc, the murine ortholog of hemojuvelin gene, is modulated by development and inflammation, but not by iron status or erythropoietin

Mutations of hepcidin (HAMP) and hemojuvelin (HJV) genes have been recently demonstrated to result in juvenile hemochromatosis. Expression of HAMP is regulated by iron status or infection, whereas regulation of HJV is yet unknown. Using quantitative real-time polymerase chain reaction, we compared expression of Hamp and Rgmc (the murine ortholog of HJV) in livers of mice treated with iron, erythropoietin, or lipopolysaccharide (ILPS), as well as during fetal and postnatal development. Iron overload increased Hamp expression without effect on Rgmc mRNA. Erythropoietin decreased Hamp mRNA, but Rgmc expression was unchanged. Hamp mRNA level decreased after birth by 4 orders of magnitude, without significant changes in Rgmc expression. Administration of LIPS elevated Hamp mRNA levels, while markedly decreasing hepatic Rgmc mRNA levels (to similar to5% after 6 hours). The responses of Hamp and Rgmc were quite different and suggested that human HJV expression could be modulated by inflammation. (C) 2004 by The American Society of Hematology.