The Down-Regulation of Clusterin Expression Enhances the αSynuclein Aggregation Process

Area of Science:

• Neuroscience
• Molecular Biology
• Cell Biology

Background:

• Parkinson's Disease (PD) involves alpha-synuclein (αSyn) aggregation in neurons.
• Molecular chaperones, like Clusterin (CLU), manage protein homeostasis and can mitigate toxic aggregation.
• CLU's role in PD pathogenesis remains largely unexplored, despite its known function in Alzheimer's Disease.

Purpose of the Study:

• To investigate the role of Clusterin (CLU) in the aggregation of alpha-synuclein (αSyn) in Parkinson's Disease models.
• To determine if CLU expression is altered in response to αSyn overexpression.
• To elucidate the functional significance of CLU in αSyn aggregation and cellular response.

Main Methods:

• Utilized SH-SY5Y cells stably overexpressing αSyn (SH-Syn).
• Assessed CLU expression levels and its localization within insoluble aggregates.
• Investigated the impact of CLU down-regulation on αSyn aggregation and cell viability.
• Confirmed the direct interaction between CLU and αSyn using co-immunoprecipitation (co-IP).

Main Results:

• αSyn overexpression significantly increased CLU expression, but not other major chaperones (Hsp27, Hsp70, Hsp90).
• Induced αSyn aggregation led to CLU accumulating in insoluble protein aggregates.
• Down-regulation of CLU resulted in increased αSyn aggregation without affecting cell viability or the Unfolded Protein Response (UPR).
• A direct molecular interaction between CLU and αSyn was confirmed via co-IP assays.

Conclusions:

• Clusterin (CLU) is upregulated in response to alpha-synuclein (αSyn) burden.
• CLU directly interacts with αSyn and is sequestered into insoluble aggregates during PD-like pathology.
• CLU plays a protective role by counteracting αSyn aggregation, making it a potential therapeutic target for Parkinson's Disease.