Iron metabolism in macrophages from HFE hemochromatosis patients

• Published in: Molecular genetics and metabolism Vol. 101; no. 2-3; pp. 258 - 267
• Main Authors: Jacolot, Sandrine, Yang, Yizhen, Paitry, Pierrick, Férec, Claude, Mura, Catherine
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.10.2010
• Subjects: Adolescent; Adult; Aged; C282Y mutation; Cell culture; Cells, Cultured; Female; Ferritins - genetics; Ferritins - metabolism; Fluoresceins - metabolism; Hemochromatosis - genetics; Hemochromatosis - metabolism; Hemochromatosis Protein; Histocompatibility Antigens Class I - genetics; Homeostasis; Humans; Iron - metabolism; Iron overload; Macrophages - metabolism; Male; Membrane Proteins - genetics; Middle Aged; RNA, Messenger - metabolism; Iron overload; TfR; C282Y mutation; Tf; FeCi; EPO; Homeostasis; NTBI
• ISSN: 1096-7192; 1096-7206
• DOI: 10.1016/j.ymgme.2010.07.010

HFE-linked hereditary hemochromatosis is a common form of iron-overload disease in European populations. We studied the role of HFE in macrophage iron metabolism. Patients under venesection treatment had higher EPO levels and drastically reduced levels of transferrin receptor (TfRC and TfR2) mRNA, and also decreased levels of HAMP mRNA in macrophages cultured in autologous serum. Macrophages from C282Y/C282Y patients cultured either in autologous serum or in FBS with or without iron supplementation, had elevated CYBRD1 (cytochrome b reductase 1), SLC40A1 (ferroportin) and FTL (ferritin L) mRNA levels. Those incubated with holo-Tf also showed lower levels of TfRC and TfR2 mRNA. Iron flux from C282Y/C282Y macrophages incubated with a low concentration of non-transferrin-bound iron (NTBI) was similar to that from wild-type macrophages, but incubation with holo-Tf or high NTBI did not trigger a continuous increase in the cytosolic calcein-chelatable iron pool in C282Y/C282Y macrophages conversely to wild-type cells. All culture conditions revealed a high level of intracellular ferritin in C282Y/C282Y macrophages compared to wild-type cells. These results suggest that the non-functional C282Y form of HFE may alter the balance between cytosolic calcein-chelatable iron and sequestered iron, thereby disrupting the iron uptake and release equilibrium in cells involved in iron storage.