The Alzheimer's disease amyloid precursor protein modulates copper-induced toxicity and oxidative stress in primary neuronal cultures.
The amyloid precursor protein (APP) of Alzheimer's disease can reduce copper (II) to copper (I) in a cell-free system potentially leading to increased oxidative stress in neurons. We used neuronal cultures derived from APP knock-out (APP(-/-)) and wild-type (WT) mice to examine the role of APP in copper neurotoxicity. WT cortical, cerebellar, and hippocampal neurons were significantly more susceptible than their respective APP(-/-) neurons to toxicity induced by physiological concentrations of copper but not by zinc or iron. There was no difference in copper toxicity between APLP2(-/-) and WT neurons, demonstrating specificity for APP-associated copper toxicity. Copper uptake was the same in WT and APP(-/-) neurons, suggesting APP may interact with copper to induce a localized increase in oxidative stress through copper (I) production. This was supported by significantly higher levels of copper-induced lipid peroxidation in WT neurons. Treatment of neuronal cultures with a peptide corresponding to the human APP copper-binding domain (APP142-166) potentiated copper but not iron or zinc toxicity. Incubation of APP142-166 with low-density lipoprotein (LDL) and copper resulted in significantly increased lipid peroxidation compared to copper and LDL alone. Substitution of the copper coordinating histidine residues with asparagines (APP142-166(H147N, H149N, H151N)) abrogated the toxic effects. A peptide corresponding to the zinc-binding domain (APP181-208) failed to induce copper or zinc toxicity in neuronal cultures. These data support a role for the APP copper-binding domain in APP-mediated copper (I) generation and toxicity in primary neurons, a process that has important implications for Alzheimer's disease and other neurodegenerative disorders.
White
A R
AR
Department of Pathology, The University of Melbourne, Parkville, 3052 Victoria, Australia.
Multhaup
G
G
Maher
F
F
Bellingham
S
S
Camakaris
J
J
Zheng
H
H
Bush
A I
AI
Beyreuther
K
K
Masters
C L
CL
Cappai
R
R
D000595:Amino Acid Sequence; D016564:Amyloid beta-Protein Precursor / Q000172:deficiency / Q000235:genetics / Q000494:pharmacology / Q000502:physiology*; D000818:Animals; D001665:Binding Sites; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D003300:Copper / Q000493:pharmacokinetics / Q000633:toxicity*; D006801:Humans; D015227:Lipid Peroxidation / Q000187:drug effects; D051379:Mice; D018345:Mice, Knockout; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000172:deficiency / Q000235:genetics / Q000502:physiology*; D009474:Neurons / Q000166:cytology* / Q000187:drug effects / Q000502:physiology*; D018384:Oxidative Stress / Q000187:drug effects / Q000502:physiology*; D010446:Peptide Fragments / Q000378:metabolism / Q000494:pharmacology*; D015032:Zinc / Q000494:pharmacology
C489697:APLP1 protein, human; C084104:APLP2 protein, human; D016564:Amyloid beta-Protein Precursor; C078201:Aplp1 protein, mouse; C492952:Aplp2 protein, mouse; D009419:Nerve Tissue Proteins; D010446:Peptide Fragments; D003300:Copper; D015032:Zinc