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Proliferation of amyloid-beta 42 aggregates occurs through a secondary nucleation mechanism

Cohen, Samuel I. A.; Linse, Sara LU ; Luheshi, Leila M.; Hellstrand, Erik LU ; White, Duncan A.; Rajah, Luke; Otzen, Daniel E.; Vendruscolo, Michele; Dobson, Christopher M. and Knowles, Tuomas P. J. (2013) In Proceedings of the National Academy of Sciences 110(24). p.9758-9763
Abstract
The generation of toxic oligomers during the aggregation of the amyloid-beta (A beta) peptide A beta 42 into amyloid fibrils and plaques has emerged as a central feature of the onset and progression of Alzheimer's disease, but the molecular pathways that control pathological aggregation have proved challenging to identify. Here, we use a combination of kinetic studies, selective radiolabeling experiments, and cell viability assays to detect directly the rates of formation of both fibrils and oligomers and the resulting cytotoxic effects. Our results show that once a small but critical concentration of amyloid fibrils has accumulated, the toxic oligomeric species are predominantly formed from monomeric peptide molecules through a... (More)
The generation of toxic oligomers during the aggregation of the amyloid-beta (A beta) peptide A beta 42 into amyloid fibrils and plaques has emerged as a central feature of the onset and progression of Alzheimer's disease, but the molecular pathways that control pathological aggregation have proved challenging to identify. Here, we use a combination of kinetic studies, selective radiolabeling experiments, and cell viability assays to detect directly the rates of formation of both fibrils and oligomers and the resulting cytotoxic effects. Our results show that once a small but critical concentration of amyloid fibrils has accumulated, the toxic oligomeric species are predominantly formed from monomeric peptide molecules through a fibril-catalyzed secondary nucleation reaction, rather than through a classical mechanism of homogeneous primary nucleation. This catalytic mechanism couples together the growth of insoluble amyloid fibrils and the generation of diffusible oligomeric aggregates that are implicated as neurotoxic agents in Alzheimer's disease. These results reveal that the aggregation of A beta 42 is promoted by a positive feedback loop that originates from the interactions between the monomeric and fibrillar forms of this peptide. Our findings bring together the main molecular species implicated in the A beta aggregation cascade and suggest that perturbation of the secondary nucleation pathway identified in this study could be an effective strategy to control the proliferation of neurotoxic A beta 42 oligomers. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
chemical kinetics, molecular mechanisms, protein misfolding, neurodegeneration
in
Proceedings of the National Academy of Sciences
volume
110
issue
24
pages
9758 - 9763
publisher
National Acad Sciences
external identifiers
  • wos:000320930100045
  • scopus:84878994873
ISSN
1091-6490
DOI
10.1073/pnas.1218402110
language
English
LU publication?
yes
id
5544986c-6ec2-4b55-a1f4-2ab97b5ae997 (old id 3979089)
date added to LUP
2013-08-23 12:21:25
date last changed
2019-11-10 03:04:49
@article{5544986c-6ec2-4b55-a1f4-2ab97b5ae997,
  abstract     = {The generation of toxic oligomers during the aggregation of the amyloid-beta (A beta) peptide A beta 42 into amyloid fibrils and plaques has emerged as a central feature of the onset and progression of Alzheimer's disease, but the molecular pathways that control pathological aggregation have proved challenging to identify. Here, we use a combination of kinetic studies, selective radiolabeling experiments, and cell viability assays to detect directly the rates of formation of both fibrils and oligomers and the resulting cytotoxic effects. Our results show that once a small but critical concentration of amyloid fibrils has accumulated, the toxic oligomeric species are predominantly formed from monomeric peptide molecules through a fibril-catalyzed secondary nucleation reaction, rather than through a classical mechanism of homogeneous primary nucleation. This catalytic mechanism couples together the growth of insoluble amyloid fibrils and the generation of diffusible oligomeric aggregates that are implicated as neurotoxic agents in Alzheimer's disease. These results reveal that the aggregation of A beta 42 is promoted by a positive feedback loop that originates from the interactions between the monomeric and fibrillar forms of this peptide. Our findings bring together the main molecular species implicated in the A beta aggregation cascade and suggest that perturbation of the secondary nucleation pathway identified in this study could be an effective strategy to control the proliferation of neurotoxic A beta 42 oligomers.},
  author       = {Cohen, Samuel I. A. and Linse, Sara and Luheshi, Leila M. and Hellstrand, Erik and White, Duncan A. and Rajah, Luke and Otzen, Daniel E. and Vendruscolo, Michele and Dobson, Christopher M. and Knowles, Tuomas P. J.},
  issn         = {1091-6490},
  keyword      = {chemical kinetics,molecular mechanisms,protein misfolding,neurodegeneration},
  language     = {eng},
  number       = {24},
  pages        = {9758--9763},
  publisher    = {National Acad Sciences},
  series       = {Proceedings of the National Academy of Sciences},
  title        = {Proliferation of amyloid-beta 42 aggregates occurs through a secondary nucleation mechanism},
  url          = {http://dx.doi.org/10.1073/pnas.1218402110},
  volume       = {110},
  year         = {2013},
}