Consequences of expressing mutants of the hemochromatosis gene (HFE) into a human neuronal cell line lacking endogenous HFE

FASEB J. 2007 Feb;21(2):564-76. doi: 10.1096/fj.06-6397com. Epub 2006 Dec 27.

Abstract

HFE mutations have traditionally been associated with the iron overload disorder known as hemochromatosis. Recently, it has become clear that the two most common mutations in the HFE gene, H63D and C282Y, may be genetic modifiers for risk of neurodegenerative disorders and cancer, respectively. We developed human neuroblastoma stable cell lines that express either wild-type (WT) or mutant HFE to determine the cellular consequences of the mutant forms of HFE. The presence of the C282Y mutation was associated with relatively higher labile iron pool and iron regulatory protein activity than WT or H63D HFE. Targeted gene arrays revealed that the signal transduction pathway was up-regulated in the C282Y cells. H63D cells had higher levels of lipid peroxidation, protein oxidation, and lower mitochondrial membrane potential, suggesting higher baseline stress. This cell line was also more vulnerable to exposure to oxidative stress agents and more responsive to iron chelation than the C282Y cells. These data demonstrate that the different mutations in the HFE gene have unique effects on the cells and provide insights into how the different mutations may have different clinical consequences. The results also raise multiple novel questions for future study about the function of the HFE protein.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Blotting, Western
  • Cell Line, Tumor
  • Cell Survival / drug effects
  • Deferoxamine / pharmacology
  • Gene Expression Profiling
  • Gene Expression Regulation, Neoplastic
  • Hemochromatosis Protein
  • Histocompatibility Antigens Class I / genetics
  • Histocompatibility Antigens Class I / metabolism
  • Histocompatibility Antigens Class I / physiology*
  • Humans
  • Hydrogen Peroxide / pharmacology
  • Iron / antagonists & inhibitors
  • Iron / metabolism
  • Iron Chelating Agents / pharmacology
  • Iron-Regulatory Proteins / genetics
  • Iron-Regulatory Proteins / metabolism
  • Membrane Proteins / genetics
  • Membrane Proteins / metabolism
  • Membrane Proteins / physiology*
  • Mutant Proteins / genetics
  • Mutant Proteins / metabolism
  • Mutant Proteins / physiology*
  • Mutation*
  • Neurons / metabolism
  • Oligonucleotide Array Sequence Analysis
  • Oxidative Stress
  • Reverse Transcriptase Polymerase Chain Reaction
  • Transfection

Substances

  • HFE protein, human
  • Hemochromatosis Protein
  • Histocompatibility Antigens Class I
  • Iron Chelating Agents
  • Iron-Regulatory Proteins
  • Membrane Proteins
  • Mutant Proteins
  • Hydrogen Peroxide
  • Iron
  • Deferoxamine