Serum soluble transferrin receptor concentrations are increased in central obesity. Results from a screening programme for hereditary hemochromatosis in men with hyperferritinemia.
A study of genes that may modulate the expression of hereditary hemochromatosis: transferrin receptor-1, ferroportin, ceruloplasmin, ferritin light and heavy chains, iron regulatory proteins (IRP)-1 and -2, and hepcidin.
The mutation responsible for 83% of HH (C260Y) results in the failure of HFE to form a critical disulfide bond, bind beta2 microglobulin, bind TfR, and traffic to the cell surface.
The transferrin receptor (TfR) interacts with two proteins important for iron metabolism, transferrin (Tf) and HFE, the protein mutated in hereditary hemochromatosis.
The recent finding that a physical interaction between HFE and transferrin receptor establishes a functional link between HFE and transferrin receptor-mediated iron metabolism in the pathophysiology of hereditary hemochromatosis.
The wild-type HH (HFE) protein complexes with the transferrin receptor (TFR), and two HFE mutations (Cys282Tyr and His63Asp) have been found to increase the affinity of the TFR for transferrin resulting in an increased cellular uptake of iron.
Functional as well as molecular studies of the HFE protein have indicated that the molecule is involved in iron metabolism and that the HFE gene variations observed among HH patients affect its interaction with the transferrin receptor (TfR).
To determine the potential role for TfR2 in iron uptake by liver, we investigated TfR and TfR2 expression in normal mice and murine models of dietary iron overload (2% carbonyl iron), dietary iron deficiency (gastric parietal cell ablation), and HH (HFE -/-).
Recent demonstration of an association between transferrin receptor (TfR) and HFE, a major histocompatibility complex class I-like molecule that has been implicated to play a role in hereditary hemochromatosis, further strengthens the notion that HFE is involved in iron metabolism.
These results establish a molecular link between HFE and a key protein involved in iron transport, the TfR, and raise the possibility that alterations in this regulatory mechanism may play a role in the pathogenesis of hereditary hemochromatosis.
In RE cells of GH subjects, we examined the activity of iron regulatory protein (IRP), a reliable indicator of the elusive regulatory labile iron pool, which modulates cellular iron homeostasis through control of ferritin (Ft) and transferrin receptor gene expression.
In fact, a lower signal for transferrin receptor messenger RNA was consistently detected in iron-overloaded patients vs. control subjects, particularly in patients with thalassemia major and idiopathic hemochromatosis (p less than 0.001).