Mutant HFE H63D protein is associated with prolonged endoplasmic reticulum stress and increased neuronal vulnerability

Yiting Liu, Sang Lee, Elizabeth Neely, Wint Nandar, Mthabisi Moyo, Zachary Simmons, James Connor

Research output: Contribution to journalArticle

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Abstract

A specific polymorphism in the hemochromatosis (HFE) gene, H63D, is over-represented in neurodegenerative disorders such as amyotrophic lateral sclerosis and Alzheimer disease. Mutations of HFE are best known as being associated with cellular iron overload, but the mechanism by which HFE H63D might increase the risk of neuron degeneration is unclear. Here, using an inducible expression cell model developed from a human neuronal cell line SH-SY5Y, we reported that the presence of the HFE H63D protein activated the unfolded protein response (UPR). This response was followed by a persistent endoplasmic reticulum (ER) stress, as the signals of UPR sensors attenuated and followed by up-regulation of caspase-3 cleavage and activity. Our in vitro findings were recapitulated in a transgenic mouse model carrying Hfe H67D, the mouse equivalent of the human H63D mutation. In this model, UPR activation was detected in the lumbar spinal cord at 6 months then declined at 12 months in association with increased caspase-3 cleavage. Moreover, upon the prolonged ER stress, the number of cells expressing HFE H63D in early apoptosis was increased moderately. Cell proliferation was decreased without increased cell death. Additionally, despite increased iron level in cells carrying HFE H63D, it appeared that ER stress was not responsive to the change of cellular iron status. Overall, our studies indicate that the HFE H63D mutant protein is associated with prolonged ER stress and chronically increased neuronal vulnerability.

Original languageEnglish (US)
Pages (from-to)13161-13170
Number of pages10
JournalJournal of Biological Chemistry
Volume286
Issue number15
DOIs
StatePublished - Apr 15 2011

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Endoplasmic Reticulum Stress
Mutant Proteins
Unfolded Protein Response
Iron
Caspase 3
Spinal Cord
Proteins
Cells
Nerve Degeneration
Protein Unfolding
Mutation
Iron Overload
Hemochromatosis
Amyotrophic Lateral Sclerosis
Cell proliferation
Cell death
Polymorphism
Neurodegenerative Diseases
Transgenic Mice
Neurons

All Science Journal Classification (ASJC) codes

  • Biochemistry
  • Molecular Biology
  • Cell Biology

Cite this

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title = "Mutant HFE H63D protein is associated with prolonged endoplasmic reticulum stress and increased neuronal vulnerability",
abstract = "A specific polymorphism in the hemochromatosis (HFE) gene, H63D, is over-represented in neurodegenerative disorders such as amyotrophic lateral sclerosis and Alzheimer disease. Mutations of HFE are best known as being associated with cellular iron overload, but the mechanism by which HFE H63D might increase the risk of neuron degeneration is unclear. Here, using an inducible expression cell model developed from a human neuronal cell line SH-SY5Y, we reported that the presence of the HFE H63D protein activated the unfolded protein response (UPR). This response was followed by a persistent endoplasmic reticulum (ER) stress, as the signals of UPR sensors attenuated and followed by up-regulation of caspase-3 cleavage and activity. Our in vitro findings were recapitulated in a transgenic mouse model carrying Hfe H67D, the mouse equivalent of the human H63D mutation. In this model, UPR activation was detected in the lumbar spinal cord at 6 months then declined at 12 months in association with increased caspase-3 cleavage. Moreover, upon the prolonged ER stress, the number of cells expressing HFE H63D in early apoptosis was increased moderately. Cell proliferation was decreased without increased cell death. Additionally, despite increased iron level in cells carrying HFE H63D, it appeared that ER stress was not responsive to the change of cellular iron status. Overall, our studies indicate that the HFE H63D mutant protein is associated with prolonged ER stress and chronically increased neuronal vulnerability.",
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Mutant HFE H63D protein is associated with prolonged endoplasmic reticulum stress and increased neuronal vulnerability. / Liu, Yiting; Lee, Sang; Neely, Elizabeth; Nandar, Wint; Moyo, Mthabisi; Simmons, Zachary; Connor, James.

In: Journal of Biological Chemistry, Vol. 286, No. 15, 15.04.2011, p. 13161-13170.

Research output: Contribution to journalArticle

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T1 - Mutant HFE H63D protein is associated with prolonged endoplasmic reticulum stress and increased neuronal vulnerability

AU - Liu, Yiting

AU - Lee, Sang

AU - Neely, Elizabeth

AU - Nandar, Wint

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AU - Simmons, Zachary

AU - Connor, James

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