Mitochondria-immobilized pH-sensitive off-on fluorescent probe.

Area of Science:

• Biochemistry
• Cell Biology
• Molecular Imaging

Background:

• Mitochondrial pH is a critical regulator of cellular functions.
• Accurate measurement of mitochondrial pH is essential for understanding cellular health and disease.
• Existing methods for monitoring mitochondrial pH have limitations in real-time and live-cell applications.

Purpose of the Study:

• To develop and characterize a novel mitochondria-targetable, pH-sensitive fluorescent probe.
• To enable quantitative measurement and real-time monitoring of mitochondrial pH dynamics in live cells.
• To investigate pH-related physiological effects and organelle dynamics in cellular processes like mitophagy.

Main Methods:

• Synthesis of a mitochondria-targetable probe incorporating a naphthalimide fluorophore, a triphenylphosphonium targeting group, and a reactive benzyl chloride moiety.
• Utilizing fluorescence microscopy for real-time monitoring of probe response to mitochondrial pH changes in live cells.
• Applying the probe to study mitochondrial function during nutrient starvation-induced mitophagy.

Main Results:

• The developed probe successfully targets mitochondria and exhibits an off-on fluorescence response to mitochondrial acidification.
• Quantitative measurements of mitochondrial pH changes in live cells were achieved.
• The probe effectively monitored impaired mitochondria during nutrient starvation and mitophagic elimination.

Conclusions:

• This mitochondria-targetable pH-sensitive probe provides a valuable tool for quantitative and real-time assessment of mitochondrial pH.
• The probe facilitates the study of organelle-specific dynamics related to the transition between physiological and pathological states.
• This technology has potential applications in understanding mitochondrial dysfunction in various diseases.