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Acceleration of α-Synuclein Aggregation by Exosomes

Exosomes are small vesicles released from cells into extracellular space. We have isolated exosomes from neuroblastoma cells and investigated their influence on the aggregation of α-synuclein, a protein associated with Parkinson disease pathology. Using cryo-transmission electron microscopy of exoso...

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Autores principales: Grey, Marie, Dunning, Christopher J., Gaspar, Ricardo, Grey, Carl, Brundin, Patrik, Sparr, Emma, Linse, Sara
Formato: Online Artículo Texto
Lenguaje:English
Publicado: American Society for Biochemistry and Molecular Biology 2015
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4317028/
https://www.ncbi.nlm.nih.gov/pubmed/25425650
http://dx.doi.org/10.1074/jbc.M114.585703
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author Grey, Marie
Dunning, Christopher J.
Gaspar, Ricardo
Grey, Carl
Brundin, Patrik
Sparr, Emma
Linse, Sara
author_facet Grey, Marie
Dunning, Christopher J.
Gaspar, Ricardo
Grey, Carl
Brundin, Patrik
Sparr, Emma
Linse, Sara
author_sort Grey, Marie
collection PubMed
description Exosomes are small vesicles released from cells into extracellular space. We have isolated exosomes from neuroblastoma cells and investigated their influence on the aggregation of α-synuclein, a protein associated with Parkinson disease pathology. Using cryo-transmission electron microscopy of exosomes, we found spherical unilamellar vesicles with a significant protein content, and Western blot analysis revealed that they contain, as expected, the proteins Flotillin-1 and Alix. Using thioflavin T fluorescence to monitor aggregation kinetics, we found that exosomes catalyze the process in a similar manner as a low concentration of preformed α-synuclein fibrils. The exosomes reduce the lag time indicating that they provide catalytic environments for nucleation. The catalytic effects of exosomes derived from naive cells and cells that overexpress α-synuclein do not differ. Vesicles prepared from extracted exosome lipids accelerate aggregation, suggesting that the lipids in exosomes are sufficient for the catalytic effect to arise. Using mass spectrometry, we found several phospholipid classes in the exosomes, including phosphatidylcholine, phosphatidylserine, phosphatidylethanolamine, phosphatidylinositol, and the gangliosides GM2 and GM3. Within each class, several species with different acyl chains were identified. We then prepared vesicles from corresponding pure lipids or defined mixtures, most of which were found to retard α-synuclein aggregation. As a striking exception, vesicles containing ganglioside lipids GM1 or GM3 accelerate the process. Understanding how α-synuclein interacts with biological membranes to promote neurological disease might lead to the identification of novel therapeutic targets.
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spelling pubmed-43170282015-02-13 Acceleration of α-Synuclein Aggregation by Exosomes Grey, Marie Dunning, Christopher J. Gaspar, Ricardo Grey, Carl Brundin, Patrik Sparr, Emma Linse, Sara J Biol Chem Molecular Biophysics Exosomes are small vesicles released from cells into extracellular space. We have isolated exosomes from neuroblastoma cells and investigated their influence on the aggregation of α-synuclein, a protein associated with Parkinson disease pathology. Using cryo-transmission electron microscopy of exosomes, we found spherical unilamellar vesicles with a significant protein content, and Western blot analysis revealed that they contain, as expected, the proteins Flotillin-1 and Alix. Using thioflavin T fluorescence to monitor aggregation kinetics, we found that exosomes catalyze the process in a similar manner as a low concentration of preformed α-synuclein fibrils. The exosomes reduce the lag time indicating that they provide catalytic environments for nucleation. The catalytic effects of exosomes derived from naive cells and cells that overexpress α-synuclein do not differ. Vesicles prepared from extracted exosome lipids accelerate aggregation, suggesting that the lipids in exosomes are sufficient for the catalytic effect to arise. Using mass spectrometry, we found several phospholipid classes in the exosomes, including phosphatidylcholine, phosphatidylserine, phosphatidylethanolamine, phosphatidylinositol, and the gangliosides GM2 and GM3. Within each class, several species with different acyl chains were identified. We then prepared vesicles from corresponding pure lipids or defined mixtures, most of which were found to retard α-synuclein aggregation. As a striking exception, vesicles containing ganglioside lipids GM1 or GM3 accelerate the process. Understanding how α-synuclein interacts with biological membranes to promote neurological disease might lead to the identification of novel therapeutic targets. American Society for Biochemistry and Molecular Biology 2015-01-30 2014-11-25 /pmc/articles/PMC4317028/ /pubmed/25425650 http://dx.doi.org/10.1074/jbc.M114.585703 Text en © 2015 by The American Society for Biochemistry and Molecular Biology, Inc. Author's Choice—Final version full access. Creative Commons Attribution Unported License (http://creativecommons.org/licenses/by/3.0/) applies to Author Choice Articles
spellingShingle Molecular Biophysics
Grey, Marie
Dunning, Christopher J.
Gaspar, Ricardo
Grey, Carl
Brundin, Patrik
Sparr, Emma
Linse, Sara
Acceleration of α-Synuclein Aggregation by Exosomes
title Acceleration of α-Synuclein Aggregation by Exosomes
title_full Acceleration of α-Synuclein Aggregation by Exosomes
title_fullStr Acceleration of α-Synuclein Aggregation by Exosomes
title_full_unstemmed Acceleration of α-Synuclein Aggregation by Exosomes
title_short Acceleration of α-Synuclein Aggregation by Exosomes
title_sort acceleration of α-synuclein aggregation by exosomes
topic Molecular Biophysics
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4317028/
https://www.ncbi.nlm.nih.gov/pubmed/25425650
http://dx.doi.org/10.1074/jbc.M114.585703
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