AUTHOR=Mao Hengxu , Ye Yongyi , Sun Xiang , Qian Chen , Wang Baoyan , Xie Linghai , Zhang Shizhong TITLE=Quiescent Elongation of α-Synuclein Pre-form Fibrils Under Different Solution Conditions JOURNAL=Frontiers in Neuroscience VOLUME=16 YEAR=2022 URL=https://www.frontiersin.org/journals/neuroscience/articles/10.3389/fnins.2022.902077 DOI=10.3389/fnins.2022.902077 ISSN=1662-453X ABSTRACT=

The intracellular aggregation of α-synuclein in neurons/glia is considered to be a key step in the pathogenesis of synucleinopathy [including Parkinson’s disease (PD), dementia with Lewy body (DLB), multiple system atrophy (MSA), etc.]. Increasing evidence indicates that the initial pathological α-synuclein aggregates can replicate themselves and propagate in a “seeding” manner to multiple areas of the brain and even to peripheral tissue, which makes it the most important biomarker for the diagnosis of synucleinopathies in recent years. The amplification and propagation capabilities of α-synuclein aggregates are very similar to those of prion-like diseases, which are based on the inherent self-recruitment capabilities of existing misfolded proteins. In vitro, the rapid recruitment process can be reproduced in a simplified model by adding a small amount of α-synuclein pre-formed fibrils to the monomer solution as fibril seeds, which may partially reveal the properties of α-synuclein aggregates. In this study, we explored the elongation rate of α-synuclein pre-formed fibrils under a quiescent incubation condition (rather than shaking/agitating). By using the ThT fluorescence assay, we compared and quantified the elongation fluorescence curves to explore the factors that affect fibril elongation. These factors include proteins’ concentration, temperature, NaCl strength, SDS, temperature pretreatment, and so on. Our work further describes the elongation of α-synuclein fibrils under quiescent incubation conditions. This may have important implications for the in vitro amplification and preservation of α-synuclein aggregates to further understand the prion-like transmission mechanism of PD.