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- Lau, Heather H. C., et al.
(författare)
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The G51D SNCA mutation generates a slowly progressive alpha-synuclein strain in early-onset Parkinson's disease
- 2023
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Ingår i: Acta neuropathologica communications. - : BioMed Central (BMC). - 2051-5960. ; 11:1
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Tidskriftsartikel (refereegranskat)abstract
- Unique strains of a-synuclein aggregates have been postulated to underlie the spectrum of clinical and pathological presentations seen across the synucleinopathies. Whereas multiple system atrophy (MSA) is associated with a predominance of oligodendroglial a-synuclein inclusions, a-synuclein aggregates in Parkinson's disease (PD) preferentially accumulate in neurons. The G51D mutation in the SNCA gene encoding a-synuclein causes an aggressive, early-onset form of PD that exhibits clinical and neuropathological traits reminiscent of both PD and MSA. To assess the strain characteristics of G51D PD a-synuclein aggregates, we performed propagation studies in M83 transgenic mice by intracerebrally inoculating patient brain extracts. The properties of the induced a-synuclein aggregates in the brains of injected mice were examined using immunohistochemistry, a conformational stability assay, and by performing a-synuclein seed amplification assays. Unlike MSA-injected mice, which developed a progressive motor phenotype, G51D PD-inoculated animals remained free of overt neurological illness for up to 18 months post-inoculation. However, a subclinical synucleinopathy was present in G51D PD-inoculated mice, characterized by the accumulation of a-synuclein aggregates in restricted regions of the brain. The induced a-synuclein aggregates in G51D PD-injected mice exhibited distinct properties in a seed amplification assay and were much more stable than those present in mice injected with MSA extract, which mirrored the differences observed between human MSA and G51D PD brain samples. These results suggest that the G51D SNCA mutation specifies the formation of a slowly propagating a-synuclein strain that more closely resembles a-synuclein aggregates associated with PD than MSA.
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| 3. |
- Ruiz-Riquelme, Alejandro, et al.
(författare)
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A beta 43 aggregates exhibit enhanced prion-like seeding activity in mice
- 2021
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Ingår i: Acta neuropathologica communications. - : BMC. - 2051-5960. ; 9:1
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Tidskriftsartikel (refereegranskat)abstract
- When injected into genetically modified mice, aggregates of the amyloid-beta (A beta) peptide from the brains of Alzheimers disease (AD) patients or transgenic AD mouse models seed cerebral A beta deposition in a prion-like fashion. Within the brain, A beta exists as a pool of distinct C-terminal variants with lengths ranging from 37 to 43 amino acids, yet the relative contribution of individual C-terminal A beta variants to the seeding behavior of A beta aggregates remains unknown. Here, we have investigated the relative seeding activities of A beta aggregates composed exclusively of recombinant A beta 38, A beta 40, A beta 42, or A beta 43. Cerebral A beta 42 levels were not increased in App(NL-F) knock-in mice injected with A beta 38 or A beta 40 aggregates and were only increased in a subset of mice injected with A beta 42 aggregates. In contrast, significant accumulation of A beta 42 was observed in the brains of all mice inoculated with A beta 43 aggregates, and the extent of A beta 42 induction was comparable to that in mice injected with brain-derived A beta seeds. Mice inoculated with A beta 43 aggregates exhibited a distinct pattern of cerebral A beta pathology compared to mice injected with brain-derived A beta aggregates, suggesting that recombinant A beta 43 may polymerize into a unique strain. Our results indicate that aggregates containing longer A beta C-terminal variants are more potent inducers of cerebral A beta deposition and highlight the potential role of A beta 43 seeds as a crucial factor in the initial stages of A beta pathology in AD.
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