Enhancing mitochondrial proteostasis reduces amyloid-β proteotoxicity.

Area of Science:

• Neuroscience
• Molecular Biology
• Genetics

Background:

• Alzheimer's disease (AD) is characterized by amyloid-β peptide aggregation, but its molecular mechanisms and treatments remain poorly understood.
• Mitochondrial dysfunction is increasingly implicated in neurodegenerative diseases like AD.
• A conserved mitochondrial stress response signature involving the mitochondrial unfolded protein response (UPRmt) and mitophagy has been observed in AD models.

Purpose of the Study:

• To investigate the role of mitochondrial stress responses in amyloid-β proteotoxicity.
• To explore the potential of enhancing mitochondrial proteostasis as a therapeutic strategy for AD.

Main Methods:

• Bioinformatic analysis of human, mouse, and Caenorhabditis elegans datasets.
• Experimental validation using a C. elegans model of amyloid-β proteotoxicity (GMC101).
• Pharmacological and genetic manipulation of mitochondrial translation and mitophagy pathways.

Main Results:

• A conserved mitochondrial stress response signature involving UPRmt and mitophagy was identified in diseases with amyloid-β proteotoxicity.
• This mitochondrial stress response is essential for maintaining mitochondrial proteostasis and health in an AD worm model.
• Enhancing mitochondrial proteostasis improved fitness, extended lifespan in worms, and reduced amyloid aggregation in cellular, worm, and mouse models.

Conclusions:

• Mitochondrial proteostasis is a relevant target for delaying diseases associated with amyloid-β proteotoxicity, including Alzheimer's disease.
• Targeting mitochondrial translation and mitophagy offers a promising therapeutic avenue for AD and related disorders.