Abstract
The mechanism whereby mutations in the presenilin-1 (PS-1) gene on chromosome 14 cause early-onset inherited Alzheimer's disease are unknown. We report that PC6 neural cells (a subclone of PC12 cells) expressing PS-1 mutations (M146V and L286V) exhibit increased superoxide production, nitrotyrosine accumulation, and membrane lipid peroxidation following exposure to amyloid beta-peptide 1-42 (Abeta). Mitochondrial calcium accumulation and membrane depolarization following exposure to Abeta were enhanced in cells expressing mutant PS-1. Overexpression of mitochondrial Mn-SOD greatly reduced superoxide production, nitrotyrosine formation, membrane lipid peroxidation, intramitochondrial calcium accumulation, and membrane depolarization following exposure to Abeta and conferred resistance to the apoptosis-enhancing action of the PS-1 mutations. Nitric oxide synthase inhibitors and the peroxynitrite scavenger uric acid blocked the apoptosis-enhancing action of PS-1 mutations. The data suggest pivotal roles for superoxide production and resulting peroxynitrite formation in the pathogenic mechanism of PS-1 mutations.
Publication types
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Alzheimer Disease / genetics
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Amino Acid Substitution
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Amyloid beta-Peptides / pharmacology*
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Animals
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Apoptosis / drug effects
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Apoptosis / physiology*
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Calcium / metabolism
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Cell Survival / drug effects
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Cell Survival / physiology
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Chromosomes, Human, Pair 14
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Humans
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Intracellular Membranes / physiology
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Lipid Peroxidation / drug effects
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Membrane Lipids / metabolism
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Membrane Potentials / drug effects
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Membrane Potentials / physiology
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Membrane Proteins / genetics*
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Membrane Proteins / metabolism*
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Mitochondria / drug effects
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Mitochondria / physiology
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Mutagenesis, Site-Directed
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Neurons / cytology
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Neurons / drug effects
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Neurons / physiology*
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PC12 Cells
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Peptide Fragments / pharmacology*
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Presenilin-1
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Rats
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Reactive Oxygen Species / metabolism
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Recombinant Proteins / metabolism
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Superoxide Dismutase / metabolism
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Superoxides / metabolism*
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Tyrosine / analogs & derivatives
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Tyrosine / metabolism
Substances
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Amyloid beta-Peptides
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Membrane Lipids
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Membrane Proteins
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PSEN1 protein, human
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Peptide Fragments
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Presenilin-1
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Reactive Oxygen Species
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Recombinant Proteins
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amyloid beta-protein (1-42)
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Superoxides
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3-nitrotyrosine
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Tyrosine
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Superoxide Dismutase
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Calcium