Downregulation of hepcidin and haemojuvelin expression in the hepatocyte cell‐line HepG2 induced by thalassaemic sera

Summary β‐Thalassaemia represents a group of diseases, in which ineffective erythropoiesis is accompanied by iron overload. In a mouse model of β‐thalassaemia, we observed that the liver expressed relatively low levels of hepcidin, which is a key factor in the regulation of iron absorption by the gut and of iron recycling by the reticuloendothelial system. It was hypothesised that, despite the overt iron overload, a putative plasma factor found in β‐thalassaemia might suppress liver hepcidin expression. Sera from β‐thalassaemia and haemochromatosis (C282Y mutation) patients were compared with those of healthy individuals regarding their capacity to induce changes the expression of key genes of iron metabolism in human HepG2 hepatoma cells. Sera from β‐thalassaemia major patients induced a major decrease in hepcidin (HAMP) and lipocalin2 (oncogene 24p3) (LCN2) expression, as well as a moderate decrease in haemojuvelin (HFE2) expression, compared with sera from healthy individuals. A significant correlation was found between the degree of downregulation of HAMP and HFE2 induced by β‐thalassaemia major sera (r = 0·852, P