Tracking autophagy process with a through bond energy transfer-based ratiometric two-photon viscosity probe

Area of Science:

• Cell Biology
• Biochemistry
• Medical Imaging

Background:

• Autophagy is a critical cellular process for organismal health.
• Lysosomal viscosity increases during autophagy, making viscosity probes valuable tools.
• Existing probes lack ratiometric sensing capabilities for accurate autophagy monitoring.

Purpose of the Study:

• To design and synthesize a viscosity-sensitive, lysosome-targeted two-photon fluorescent probe.
• To enable accurate ratiometric sensing of lysosomal viscosity during autophagy.
• To visualize the role of autophagy in inflammation and stroke.

Main Methods:

• Design of a probe based on the through bond energy transfer (TBET) mechanism.
• Utilizing two-photon excitation at 810 nm for imaging.
• Measuring the ratio of red and green emission channels to determine viscosity.

Main Results:

• The developed probe, Lyso-Vis, demonstrated viscosity-dependent ratiometric fluorescence.
• Successfully achieved ratiometric sensing of lysosomal viscosity during autophagy.
• Visualized the link between autophagy, inflammation, and stroke.
• Applied to study autophagy modulation in a mouse stroke model.

Conclusions:

• Lyso-Vis provides a novel method for accurate, ratiometric monitoring of lysosomal viscosity in autophagy.
• The probe facilitates deeper understanding of autophagy's role in disease pathogenesis.
• This technology has potential applications in studying neurological conditions like stroke.