Journal article Open Access
Pantazopoulou, Marina;
Brembati, Vivianna;
Kanellidi, Angeliki;
Bousset, Luc;
Melki, Ronald;
Stefanis, Leonidas
A major pathological feature of Parkinson’s disease (PD) is the aberrant accumulation of misfolded assemblies of alpha-synuclein (α-Syn). Protein clearance appears as a regulator of the ‘’α-Syn burden” underlying PD pathogenesis. The picture emerging is that a combination of pathways with complementary roles, including the Ubiquitin Proteasome System (UPS) and the Autophagy-Lysosome Pathway (ALP), contributes to the intracellular degradation of α‐Syn. The current study addresses the mechanisms governing the degradation of α-Syn species seeded by exogenous fibrils in neuronally differentiated SH-SY5Y neuroblastoma cells with inducible expression of α-Syn (tet-off system). Using human α-Syn recombinant fibrils (pre-formed fibrils, PFFs), seeding of endogenous α-Syn occurs within a time frame of 6 days, and is still prominent after 12 days of PFF addition. Clearance of α-Syn assemblies in this inducible model was enhanced after switching off α-Syn expression with doxycycline. Lysosomal inhibition led to accumulation of PFF-induced SDS-soluble α-Syn 6 days after PFF-addition or when switching off α-Syn expression. Additionally, the autophagic enhancer, rapamycin, induced the clearance of α-Syn aggregates 13 days post-PFF addition, indicating that autophagy is the major pathway for aggregated α-Syn clearance. Fibrillar phosphorylated α-Syn at S129 was only apparent at 7 days of incubation with a higher amount of PFFs. Pharmacological inhibition of the proteasome resulted in further accumulation of PFF-induced SDS-soluble phosphorylated α-Syn at S129, without affecting total α-Syn. Our data suggest that in this inducible model autophagy is mainly responsible for the degradation of fibrillar α-Syn, whereas the Proteasome System is responsible, at least in part, for the selective clearance of PFF-induced SDS-soluble phosphorylated α-Syn at S129.
Name | Size | |
---|---|---|
Pantazopoulou et al.pdf
md5:6e07438476f7aa7b6e561d6381cbfd13 |
12.6 MB | Download |
Pantazopoulou_supp.pdf
md5:78ec109972a053ddf903aa72ef425dda |
6.7 MB | Download |
All versions | This version | |
---|---|---|
Views | 45 | 45 |
Downloads | 32 | 32 |
Data volume | 363.2 MB | 363.2 MB |
Unique views | 42 | 42 |
Unique downloads | 29 | 29 |