Constant Conversion Rate of Endolysosomes Revealed by a pH-Sensitive Fluorescent Probe

Area of Science:

• Cell Biology
• Biochemistry
• Medical Imaging

Background:

• Endolysosome dynamics are crucial for autophagosome biogenesis.
• High-resolution imaging of endolysosomes is vital for understanding autophagy and developing treatments for related diseases.

Purpose of the Study:

• To develop a novel fluorescent probe for real-time imaging of endolysosome dynamics.
• To investigate the role of endolysosome pH changes in autophagy using advanced imaging techniques.

Main Methods:

• Synthesis and characterization of a cationic quinolinium-based fluorescent probe (PyQPMe).
• Photophysical and computational studies to understand the probe's pH-sensitive fluorescence.
• Live-cell imaging experiments to monitor endolysosome dynamics during autophagy.

Main Results:

• PyQPMe demonstrated excellent pH-sensitive fluorescence, ideal for tracking endolysosomes.
• The probe exhibited a large Stokes shift and high fluorescence intensity, enabling high signal-to-noise ratio imaging.
• Live-cell imaging revealed a constant conversion rate from early endosomes to late endosomes/lysosomes during autophagy.

Conclusions:

• PyQPMe is a valuable tool for high-resolution imaging of endolysosome dynamics.
• The probe facilitates a deeper understanding of autophagy and potential therapeutic targets for endosome-related disorders.