Analysis of alpha-synuclein-associated proteins by quantitative proteomics

Area of Science:

• Neuroscience
• Biochemistry
• Toxicology

Background:

• Alpha-synuclein (AS) aggregation is a central event in neurodegenerative diseases like Parkinson's.
• Rotenone, a pesticide, induces parkinsonism and Lewy body-like inclusions, making it a relevant model for studying AS aggregation.
• Identifying proteins interacting with soluble AS is crucial for understanding aggregation mechanisms.

Purpose of the Study:

• To identify proteins associated with soluble AS that may promote its aggregation.
• To investigate the role of these proteins in rotenone-induced cytotoxicity and AS aggregation.
• To explore the protective effects of heat shock protein 70 (hsp70) against rotenone toxicity and AS aggregation.

Main Methods:

• Quantitative proteomic comparison of AS-associated protein complexes in MES cells treated with rotenone versus vehicle.
• Identification of proteins with significantly altered abundance in AS complexes under rotenone exposure.
• Overexpression of heat shock protein 70 (hsp70) to assess its impact on rotenone-induced cytotoxicity and AS aggregation.

Main Results:

• Over 250 proteins were identified in association with soluble AS.
• At least 51 proteins showed significant changes in abundance in AS complexes upon rotenone treatment.
• Overexpression of hsp70 protected cells from rotenone toxicity and reduced soluble AS aggregation.
• Hsp70's protective effect was linked to the suppression of oxidative stress, mitochondrial dysfunction, and proteasomal dysfunction.

Conclusions:

• Several proteins associated with soluble AS are modulated by rotenone exposure.
• Heat shock protein 70 (hsp70) plays a protective role against rotenone-induced neurotoxicity and AS aggregation.
• Hsp70 may represent a therapeutic target for neurodegenerative conditions involving AS pathology.