Fluorescence Lifetime Imaging Microscopy of Biomolecular Condensates.

Area of Science:

• Biochemistry
• Cell Biology
• Neuroscience

Background:

• Biomolecular condensates of ribonucleoproteins (RNPs), such as TDP-43, form via liquid-liquid phase separation (LLPS).
• These condensates are implicated in neurodegenerative diseases, acting as sites for protein aggregation and fibrillation.
• The precise mechanisms driving RNP condensate rearrangements leading to protein misfolding are not fully understood.

Purpose of the Study:

• To investigate the biochemical processes within TDP-43 condensates.
• To characterize the effects of chemical chaperones on TDP-43 LLPS and aggregation.
• To explore therapeutic strategies for RNP-associated neurodegenerative diseases.

Main Methods:

• Utilizing Fluorescence Lifetime Imaging Microscopy (FLIM) for high-resolution, spatiotemporal monitoring of in-droplet changes.
• Observing the decoupling of TDP-43 liquid-liquid phase separation (LLPS) from aggregation/fibrillation.
• Assessing the impact of chemical chaperones on condensate dynamics.

Main Results:

• FLIM successfully monitored dynamic changes within TDP-43 condensates.
• Chemical chaperones demonstrated the ability to decouple TDP-43 LLPS from subsequent aggregation.
• Spatiotemporal analysis revealed key transition points in the aggregation pathway.

Conclusions:

• FLIM is a powerful tool for dissecting RNP condensate behavior and aggregation.
• Chemical chaperones offer a potential therapeutic avenue for preventing pathological protein aggregation in neurodegenerative conditions.
• Targeting RNP condensate dynamics may provide a strategy to combat TDP-43-associated diseases without disrupting essential cellular stress responses.