Retromer regulates the lysosomal clearance of MAPT/tau

Area of Science:

• Neuroscience
• Cell Biology
• Molecular Biology

Background:

• The autophagy-lysosome pathway clears cellular waste, including protein aggregates.
• Dysfunction of this pathway and protein aggregation, like MAPT/tau, are implicated in neurodegenerative diseases such as Alzheimer's.
• The retromer complex is known to interact with MAPT, but its direct role in aggregation is unclear.

Purpose of the Study:

• To investigate the role of the retromer complex in the clearance of aggregated MAPT species.
• To determine if retromer dysfunction directly influences MAPT aggregation via the autophagy-lysosome axis.

Main Methods:

• Utilized cell models of amyloid MAPT aggregation.
• Employed chemical and genetic approaches to manipulate retromer components, specifically VPS35.
• Assessed the impact of VPS35 depletion and overexpression on autophagy resolution and MAPT aggregate levels.

Main Results:

• The autophagy-lysosome axis is the primary clearance mechanism for aggregated MAPT.
• Depletion of VPS35, a core retromer component, disrupts autophagy resolution.
• VPS35 depletion leads to significant accumulation of cytoplasmic MAPT aggregates, while VPS35 overexpression reduces them.

Conclusions:

• Retromer complex integrity is crucial for regulating the autophagy-lysosome pathway.
• Proper retromer function suppresses MAPT aggregation and its spread.
• This study highlights a direct link between retromer function and the pathogenesis of MAPT-related neurological disorders.