Cathepsin B promotes Aβ proteotoxicity by modulating aging regulating mechanisms.

Area of Science:

• Neuroscience
• Molecular Biology
• Genetics

Background:

• Certain proteases aid proteostasis and prevent neurodegeneration.
• Cathepsin B (CTSB) protease activity increases proteotoxicity in Alzheimer's disease (AD) models.
• Elevated CTSB levels are observed in AD patient brains, but its role in Aβ toxicity is debated.

Purpose of the Study:

• To investigate the mechanism by which CTSB exacerbates amyloid-beta (Aβ) peptide toxicity.
• To determine the opposing roles of CTSB in different proteotoxic insults.
• To identify potential therapeutic targets for neurodegenerative disorders.

Main Methods:

• Utilized an activity-based probe to study CTSB activity.
• Employed aging-altering interventions in model organisms.
• Conducted experiments using the nematode C. elegans to analyze gene and protein functions.

Main Results:

• CTSB, specifically CPR-6 in C. elegans, promotes Aβ proteotoxicity but reduces polyQ toxicity.
• Knockdown of cpr-6 alleviates Aβ toxicity without impacting lifespan.
• cpr-6 knockdown reduces swsn-3 expression and increases SMK-1 protein levels, impacting aging regulation.

Conclusions:

• CTSB aggravates Aβ-mediated toxicity through a specific mechanism involving aging regulation pathways.
• CTSB exhibits opposing roles in response to distinct proteotoxic insults.
• Therapeutic strategies for neurodegenerative diseases must be tailored to the specific disorder and its underlying molecular mechanisms.