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- Gustafsson, Gabriel, et al.
(författare)
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Secretion and uptake of α-synuclein via extracellular vesicles in cultured cells
- 2018
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Ingår i: Cellular and molecular neurobiology. - : Springer Science and Business Media LLC. - 0272-4340 .- 1573-6830. ; 38:8, s. 1539-1550
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Tidskriftsartikel (refereegranskat)abstract
- In Parkinson’s disease and other Lewy body disorders, the propagation of pathology has been accredited to the spreading of extracellular α-synuclein (α-syn). Although the pathogenic mechanisms are not fully understood, cell-to-cell transfer of α-syn via exosomes and other extracellular vesicles (EVs) has been reported. Here, we investigated whether altered molecular properties of α-syn can influence the distribution and secretion of α-syn in human neuroblastoma cells. Different α-syn variants, including α-syn:hemi-Venus and disease-causing mutants, were overexpressed and EVs were isolated from the conditioned medium. Of the secreted α-syn, 0.1–2% was associated with vesicles. The major part of EV α-syn was attached to the outer membrane of vesicles, whereas a smaller fraction was found in their lumen. For α-syn expressed with N-terminal hemi-Venus, the relative levels associated with EVs were higher than for WT α-syn. Moreover, such EV-associated α-syn:hemi-Venus species were internalized in recipient cells to a higher degree than the corresponding free-floating forms. Among the disease-causing mutants, A53T α-syn displayed an increased association with EVs. Taken together, our data suggest that α-syn species with presumably lost physiological functions or altered aggregation properties may shift the cellular processing towards vesicular secretion. Our findings thus lend further support to the tenet that EVs can mediate spreading of harmful α-syn species and thereby contribute to the pathology in α-synucleinopathies.
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| 2. |
- Gyorgy, Bence, et al.
(författare)
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CRISPR/Cas9 Mediated Disruption of the Swedish APP Allele as a Therapeutic Approach for Early-Onset Alzheimer's Disease
- 2018
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Ingår i: Molecular Therapy Nucleic Acids. - : CELL PRESS. - 2162-2531. ; 11, s. 429-440
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Tidskriftsartikel (refereegranskat)abstract
- The APPswe (Swedish) mutation in the amyloid precursor protein (APP) gene causes dominantly inherited Alzheimer's disease (AD) as a result of increased beta-secretase cleavage of the amyloid-beta (A beta) precursor protein. This leads to abnormally high A beta levels, not only in brain but also in peripheral tissues of mutation carriers. Here, we selectively disrupted the human mutant APP(sw) allele using CRISPR. By applying CRISPR/Cas9 from Streptococcus pyogenes, we generated allele-specific deletions of either APP(sw) or APP(WT). As measured by ELISA, conditioned media of targeted patient-derived fibroblasts displayed an approximate 60% reduction in secreted A beta. Next, coding sequences for the APP(sw)-specific guide RNA (gRNA) and Cas9 were packaged into separate adeno-associated viral (AAV) vectors. Site-specific indel formation was achieved both in primary neurons isolated from APP(sw) transgenic mouse embryos (Tg2576) and after co-injection of these vectors into hippocampus of adult mice. Taken together, we here present proof-of-concept data that CRISPR/Cas9 can selectively disrupt the APP(sw) allele both ex vivo and in vivo-and thereby decrease pathogenic A beta. Hence, this system may have the potential to be developed as a tool for gene therapy against AD caused by APPswe and other point mutations associated with increased A beta.
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