Mitochondria-immobilized fluorescent probes for viscosity and cellular imaging

Area of Science:

• Biochemistry
• Cell Biology
• Molecular Probes

Background:

• Mitochondrial viscosity is a critical indicator of cellular health and function.
• Developing precise tools to monitor intracellular environments is essential for understanding disease mechanisms.

Purpose of the Study:

• To design and synthesize a mitochondria-targeted fluorescent probe (Mito-CDM) for accurate viscosity sensing.
• To investigate the probe's performance in monitoring mitochondrial viscosity changes in living cells.

Main Methods:

• Synthesis of the Mito-CDM probe incorporating a viscosity-sensitive unit and a mitochondria-targeting group.
• Characterization of the probe's fluorescence response to varying viscosity levels (0.55–950 cp).
• Evaluation of Mito-CDM's immobilization capability via reaction with mitochondrial thiols.
• Application of the probe in HeLa cells to monitor viscosity changes during induced inflammation.

Main Results:

• Mito-CDM exhibits a gradual fluorescence enhancement with increasing viscosity, demonstrating a strong linear correlation (R² = 0.9957).
• A 166-fold fluorescence enhancement was observed in high-viscosity conditions.
• The probe successfully localized and remained immobilized within mitochondria.
• Mito-CDM effectively tracked mitochondrial viscosity alterations in response to inflammatory stimuli (nystatin and lipopolysaccharide).

Conclusions:

• Mito-CDM is a robust and sensitive fluorescent probe for real-time mitochondrial viscosity measurements.
• The probe's ability to immobilize on mitochondria allows for long-term monitoring of cellular processes.
• Mito-CDM provides valuable insights into mitochondrial dysfunction during inflammatory conditions.