| 1. |
- Heilbronner, Goetz, et al.
(författare)
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Seeded strain-like transmission of beta-amyloid morphotypes in APP transgenic mice
- 2013
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Ingår i: EMBO Reports. - : NATURE PUBLISHING GROUP, MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND. - 1469-221X .- 1469-3178. ; 14:11, s. 1017-1022
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Tidskriftsartikel (refereegranskat)abstract
- The polymorphic beta-amyloid lesions present in individuals with Alzheimers disease are collectively known as cerebral beta-amyloidosis. Amyloid precursor protein (APP) transgenic mouse models similarly develop beta-amyloid depositions that differ in morphology, binding of amyloid conformation-sensitive dyes, and A beta 40/A beta 42 peptide ratio. To determine the nature of such beta-amyloid morphotypes, beta-amyloid-containing brain extracts from either aged APP23 brains or aged APPPS1 brains were intracerebrally injected into the hippocampus of young APP23 or APPPS1 transgenic mice. APPPS1 brain extract injected into young APP23 mice induced beta-amyloid deposition with the morphological, conformational, and A beta 40/A beta 42 ratio characteristics of beta-amyloid deposits in aged APPPS1 mice, whereas APP23 brain extract injected into young APP23 mice induced b-amyloid deposits with the characteristics of beta-amyloid deposits in aged APP23 mice. Injecting the two extracts into the APPPS1 host revealed a similar difference between the induced beta-amyloid deposits, although less prominent, and the induced deposits were similar to the beta-amyloid deposits found in aged APPPS1 hosts. These results indicate that the molecular composition and conformation of aggregated A beta in APP transgenic mice can be maintained by seeded conversion.
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| 2. |
- Novotny, Renata, et al.
(författare)
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Conversion of Synthetic A beta to In Vivo Active Seeds and Amyloid Plaque Formation in a Hippocampal Slice Culture Model
- 2016
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Ingår i: Journal of Neuroscience. - : SOC NEUROSCIENCE. - 0270-6474 .- 1529-2401. ; 36:18, s. 5084-5093
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Tidskriftsartikel (refereegranskat)abstract
- The aggregation of amyloid-beta peptide (A beta) inbrain is an early event and hallmark of Alzheimers disease (AD). We combined the advantages of in vitro and in vivo approaches to study cerebral beta-amyloidosis by establishing a long-term hippocampal slice culture(HSC) model. While no A beta deposition was noted in untreated HSCs of postnatal A beta precursor protein transgenic (APP tg) mice, A beta deposition emerged in HSCs when cultures were treated once with brain extract from aged APP tg mice and the culture medium was continuously supplemented with synthetic A beta. Seeded A beta deposition was also observed under the same conditions in HSCs derived from wild-type or App-null mice but in no comparable way when HSCs were fixed before cultivation. Both the nature of the brain extract and the synthetic A beta species determined the conformational characteristics of HSCA beta deposition. HSCA beta deposits induced a microglia response, spine loss, and neuritic dystrophy but no obvious neuron loss. Remarkably, in contrast to in vitro aggregated synthetic A beta, homogenates of A beta deposits containing HSCs induced cerebral beta-amyloidosis upon intracerebral inoculation into young APP tg mice. Our results demonstrate that a living cellular environment promotes the seeded conversion of synthetic A beta into a potent in vivo seeding-active form.
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