Amyloid Fibrils Are the Molecular Trigger of Inflammation in Parkinson's Disease

GUSTOT A; GALLEA JI; SARROUKH R; CELEJ MS; RUYSSCHAERT JM; RAUSSENS V

BIOCHEMICAL JOURNAL

PORTLAND PRESS LTD

Lugar: Londres; Año: 2015

0264-6021

Parkinson's disease (PD) is an age-related movement disorder characterized by a progressive degeneration of dopaminergic neurons in the mid-brain. Although the presence of amyloid deposits of α-synuclein (α-syn) is the main pathological feature, PD brains also present a severe permanent inflammation, which largely contributes to neuropathology. Although α-syn has recently been implicated in this process, the molecular mechanisms underlying neuroinflammation remain unknown. Here, we investigated the ability of different α-syn aggregates to trigger inflammatory responses. We showed that α-syn induced inflammation through activation of TLR2 and the NLRP3 inflammasome only when folded as amyloid fibrils. Oligomeric species, thought to be the primary species responsible for the disease, were surprisingly unable to trigger the same cascades. As neuroinflammation is a key player in PD pathology, these results put fibrils back to the fore and rekindles discussions about the primary toxic species contributing to the disease. Our data also suggest that the inflammatory properties of α-syn fibrils are linked to their intrinsic structure, most probably to their cross-β structure. Since fibrils of other amyloids induce similar immunological responses, we propose that the canonical fibril specific cross-β structure represents a new generic motif recognized by the innate immune system.