Pinto Jorge P, Ramos Pedro, de Sousa Maria
Iron Genes and Immune System, IBMC, Instituto de Biologia Molecular e Celular, Rua do Campo Alegre 823, 4150-180 Porto, Portugal.
Blood Cells Mol Dis. 2007 Jul-Aug;39(1):75-81. doi: 10.1016/j.bcmd.2007.01.005. Epub 2007 Apr 10.
Liver is the primary target organ of Hereditary Hemochromatosis Type I, with the HFE mutations C282Y and H63D recognized as markers of this iron-overload disease. Hepatocytes are also the main site of synthesis of HFE. However, most early studies of overexpression of HFE were done in non-hepatic, non-HFE-expressing, cell lines. Here we report the setting up of a stable transfection model of wt- and mutant-HFE (H63D and C282Y) proteins in a hepatic cell line (HepG2), the analysis of its intracellular distribution and the effect of diferric transferrin on HFE localization. The C282Y mutant is retained in the ER, whereas HFE-wt and H63D co-localize with TfR1 exclusively in early recycling endosomes. Holotransferrin induces a re-localization of wt- and H63D-HFE, from early recycling endosomes to the cytoplasmic membrane. In conclusion our results establish the HepG2 cell line as a valuable model for the study of HFE.
肝脏是I型遗传性血色素沉着症的主要靶器官，HFE突变C282Y和H63D被认为是这种铁过载疾病的标志物。肝细胞也是HFE的主要合成部位。然而，大多数关于HFE过表达的早期研究是在非肝脏、不表达HFE的细胞系中进行的。在此，我们报告了在肝细胞系（HepG2）中建立野生型和突变型HFE（H63D和C282Y）蛋白的稳定转染模型，分析其细胞内分布以及二价铁转铁蛋白对HFE定位的影响。C282Y突变体保留在内质网中，而野生型HFE和H63D仅在早期再循环内体中与转铁蛋白受体1（TfR1）共定位。全转铁蛋白诱导野生型和H63D-HFE从早期再循环内体重新定位到细胞质膜。总之，我们的结果确立了HepG2细胞系作为研究HFE的有价值模型。
