Misfolded protein aggregates represent a continuum with overlapping features in neurodegenerative diseases, but differences in protein components and affected brain regions. The molecular hallmark of synucleinopathies such as Parkinson’s disease, dementia with Lewy bodies and multiple system atrophy are megadalton α-synuclein-rich deposits suggestive of one molecular event causing distinct disease phenotypes.
A recent paper published in Nature on 18 June 2015 assesses the properties of structurally well-defined α-SYN assemblies (oligomers, ribbons and fibrils) after injection in rat brain and claims to prove that α-SYN strains amplify in vivo. Fibrils seem to be the major toxic strain, resulting in progressive motor impairment and cell death, whereas ribbons cause a distinct histopathological phenotype displaying Parkinson’s disease and multiple system atrophy traits. Additionally,they show that α-SYN assemblies cross the blood-brain barrier and distribute to the central nervous system after intravenous injection. Their results suggest that distinct α-SYN strains display differential seeding capacities, inducing strain-specific pathology and neurotoxic phenotypes.
α-Synuclein strains cause distinct synucleinopathies after local and systemic administration, Peelaerts W, Bousset L, Van der Perren A, Moskalyuk A, Pulizzi R, Giugliano M, Van den Haute C, Melki R, Baekelandt V.
Nature. 2015 Jun 18;522(7556):340-4. doi: 10.1038/nature14547. Epub 2015 Jun 10.