P4‐057: PURIFICATION AND CHARACTERIZATION OF SUBPOPULATIONS OF EXTRACELLULAR VESICLES FROM AD AND PD BRAIN AND THEIR SUPPRESSION BY NSMASE2 INHIBITORS

• DOI: 10.1016/j.jalz.2019.06.3717
• Publication Date: 2019-10-18T11:29:49Z
• Authors: Tina Bilousova; Chris Jean Elias; Mikhail Melnik; Emily Miyoshi; Jesus J. Campagna; Bryan Simmons; Asa Hatami; Chunni Zhu; Michael Jun; Whitaker Cohn; Barbara Jagodzinska; Kanagasabai Vadivel; Patricia Spilman; Neil Garg; Karen H. Gylys; Varghese John
• Keywords: Immunoprecipitation; Exosome; Microvesicle; Extracellular vesicles; Nanoparticle tracking analysis

Tau, amyloid beta (Aβ), and alpha-synuclein (αSyn) pathology can be spread from cell-to-cell by oligomers also called seeds in Alzheimer's disease (AD) Parkinson's (PD). Exosomes, small extracellular vesicles (EVs) originated multivesicular bodies, are one of the mechanisms seed transfer, but they may play an important role clearance intercellular signaling. Functional biochemical composition exosomes depend on type metabolic state their cell origin biogenesis pathway. If proteopathic accumulated some specific subpopulations EVs/exosomes is currently unknown. To address this question we purified characterized different EV depolarized human synaptosomes, cryopreserved AD brain samples, PD animal models. Cryopreserved fresh tissue was gently dissociated cells with preserved integrity were analyzed flow cytometry parallel isolation cell-specific EVs combination differential rate-zonal ultracentrifugation immunoprecipitation technics. fractions using electron microscopy analysis; seeding propagation potential evaluated tau biosensor system. Global proteomics lipidomics analyses progress. Our data demonstrate presence full-length tau, fragments, acetylated high molecular weight SDS-stable aggregates (potentially dimers), truncated αSyn fractions. The highest amount found exosomal fraction, contained uniform size (with diameters around 50 nm) vesicles, highly enriched tetraspanins syntenin-1. Moreover, stimulation inflammatory-mediated exosome release PS19 (tauopathy model) Thy1-αSyn (Parkinson's mice intracerebroventricular injections IL1β or TNFα, led to significant elevation release, which suppressed pretreatment nSMase2 inhibitors. results feasibility purification suggest a detrimental ceramide/nSMase2 pathway upregulation as therapeutics target.