Selective lysosomal H₂O₂-ROS imaging with a naphthalimide probe forming hydroxylamine without overoxidation

Area of Science:

• Cellular Biology
• Biochemistry
• Analytical Chemistry

Background:

• Hydrogen peroxide (H2O2) is crucial in cellular processes like oxidative stress and signaling.
• Monitoring H2O2 dynamics within specific cellular compartments, such as lysosomes, is analytically challenging due to its rapid changes and localization.
• Existing methods for H2O2 detection often lack specificity or biocompatibility for lysosomal environments.

Purpose of the Study:

• To develop a novel fluorescent probe, LysoH2O2, for sensitive and selective detection of H2O2 specifically within lysosomes.
• To enable real-time imaging and monitoring of H2O2 fluctuations in the lysosomal microenvironment of living cells.
• To provide an alternative to conventional probes with improved biocompatibility and a unique chemical mechanism.

Main Methods:

• Design and synthesis of LysoH2O2, a naphthalimide-derived fluorescent probe with a lysosome-targeting unit.
• Utilizing a selective chemical reaction where H2O2 transforms an amine group to a hydroxylamine, causing fluorescence enhancement.
• Employing confocal fluorescence microscopy to visualize and quantify H2O2 levels in living cells.

Main Results:

• LysoH2O2 demonstrated high sensitivity and selectivity for detecting H2O2 in lysosomes.
• The probe enabled real-time visualization of both endogenous and exogenous H2O2 changes within the lysosomal compartment.
• LysoH2O2 exhibited minimal cytotoxicity, confirming its suitability for live-cell imaging.

Conclusions:

• LysoH2O2 is an effective tool for specific lysosomal H2O2 detection and imaging.
• The probe's novel chemical mechanism offers advantages over traditional boronate-based sensors.
• This advancement facilitates better understanding of H2O2's role in lysosomal pathophysiology and cellular signaling.