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TitleLewy body extracts from Parkinson disease brains trigger α-synuclein pathology and neurodegeneration in mice and monkeys.
Publication TypeJournal Article
Year of Publication2014
AuthorsRecasens, Ariadna, Benjamin Dehay, Jordi Bové, Iria Carballo-Carbajal, Sandra Dovero, Ana Pérez-Villalba, Pierre-Olivier Fernagut, Javier Blesa, Annabelle Parent, Celine Perier, Isabel Fariñas, José A. Obeso, Erwan Bezard, and Miquel Vila
JournalAnn Neurol
Volume75
Issue3
Pagination351-62
Date Published2014 Mar
ISSN1531-8249
Keywordsalpha-Synuclein, Animals, Corpus Striatum, Dopaminergic Neurons, Female, Humans, Lewy Bodies, Macaca mulatta, Mice, Mice, Knockout, Microinjections, Nerve Degeneration, Parkinson Disease, Substantia Nigra, Tissue Extracts
Abstract

OBJECTIVE: Mounting evidence suggests that α-synuclein, a major protein component of Lewy bodies (LB), may be responsible for initiating and spreading the pathological process in Parkinson disease (PD). Supporting this concept, intracerebral inoculation of synthetic recombinant α-synuclein fibrils can trigger α-synuclein pathology in mice. However, it remains uncertain whether the pathogenic effects of recombinant synthetic α-synuclein may apply to PD-linked pathological α-synuclein and occur in species closer to humans.

METHODS: Nigral LB-enriched fractions containing pathological α-synuclein were purified from postmortem PD brains by sucrose gradient fractionation and subsequently inoculated into the substantia nigra or striatum of wild-type mice and macaque monkeys. Control animals received non-LB fractions containing soluble α-synuclein derived from the same nigral PD tissue.

RESULTS: In both mice and monkeys, intranigral or intrastriatal inoculations of PD-derived LB extracts resulted in progressive nigrostriatal neurodegeneration starting at striatal dopaminergic terminals. No neurodegeneration was observed in animals receiving non-LB fractions from the same patients. In LB-injected animals, exogenous human α-synuclein was quickly internalized within host neurons and triggered the pathological conversion of endogenous α-synuclein. At the onset of LB-induced degeneration, host pathological α-synuclein diffusely accumulated within nigral neurons and anatomically interconnected regions, both anterogradely and retrogradely. LB-induced pathogenic effects required both human α-synuclein present in LB extracts and host expression of α-synuclein.

INTERPRETATION: α-Synuclein species contained in PD-derived LB are pathogenic and have the capacity to initiate a PD-like pathological process, including intracellular and presynaptic accumulations of pathological α-synuclein in different brain areas and slowly progressive axon-initiated dopaminergic nigrostriatal neurodegeneration.

DOI10.1002/ana.24066
Alternate JournalAnn. Neurol.
PubMed ID24243558