Brain-derived exosomes from dementia with Lewy bodies propagate α-synuclein pathology

• Main Authors: Jennifer Ngolab, Ivy Trinh, Edward Rockenstein, Michael Mante, Jazmin Florio, Margarita Trejo, Deborah Masliah, Anthony Adame, Eliezer Masliah, Robert A. Rissman
• Format: Article
• Language: English
• Published: BMC 2017-06-01
• Series: Acta Neuropathologica Communications
• Subjects: Alzheimer’s disease; Exosomes; Alpha synuclein; Lewy body; Tau; Amyloid beta
• Online Access: http://link.springer.com/article/10.1186/s40478-017-0445-5

Abstract Proteins implicated in neurodegenerative conditions such as Alzheimer’s disease (AD) and Dementia with Lewy Bodies (DLB) have been identified in bodily fluids encased in extracellular vesicles called exosomes. Whether exosomes found in DLB patients can transmit pathology is not clear. In this study, exosomes were successfully harvested through ultracentrifugation from brain tissue from DLB and AD patients as well as non-diseased brain tissue. Exosomes extracted from brains diagnosed with either AD or DLB contained aggregate-prone proteins. Furthermore, injection of brain-derived exosomes from DLB patients into the brains of wild type mice induced α-synuclein (α-syn) aggregation. As assessed through immunofluorescent double labeling, α-syn aggregation was observed in MAP2+, Rab5+ neurons. Using a neuronal cell line, we also identified intracellular α-syn aggregation mediated by exosomes is dependent on recipient cell endocytosis. Together, these data suggest that exosomes from DLB patients are sufficient for seeding and propagating α-syn aggregation in vivo.