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Published on: July 22, 2013
Synthesis of polar-insensitive phenothiazine-based fluorescent probes for viscosity detection in mitochondria
Jiahui Wang1, Zixian Shen1, Xianfeng Ma1
1School of Pharmacy, Jiangsu University, Zhenjiang 212013, Jiangsu, China.
Abstract:
Mitochondria, the primary energy-producing organelles, critically regulate cellular activities. Their internal viscosity-a key microenvironmental parameter-directly affects material transport and energy conversion, with aberrant levels linked to disease pathogenesis. Most reported mitochondrial viscosity probes were susceptible to polar interference, resulting in insufficient specificity for viscosity detection. This study designed and developed a novel polar-insensitive fluorescent probe, Y-CN, based on a phenothiazine skeleton - a small molecular compound with excellent fluorescent properties. The experimental data revealed an excellent linear relationship (R2 > 0.99) between Y-CN's fluorescence intensity and viscosity over a wide range from 1.005 to 219 cP. When viscosity increased from 1.005 cP (aqueous buffer) to 219 cP, Y-CN demonstrated a dramatic 209-fold fluorescence amplification. Furthermore, the probe exhibited excellent selectivity, pH stability, and low toxicity. Moreover, Y-CN could detect viscosity changes induced by food thickeners. Y-CN successfully monitored dynamic changes in mitochondrial viscosity within live cells, providing a powerful tool for specific investigation of mitochondria-associated physiological and pathological processes, with significant potential for biological applications.
Insights
Researchers developed a novel fluorescent probe, Y-CN, to accurately measure mitochondrial viscosity. This tool overcomes limitations of previous probes and offers specific insights into cellular processes and diseases.
Area of Science:
- Cell Biology
- Biochemistry
- Molecular Probes
Background:
- Mitochondria are vital organelles regulating cellular functions through energy production.
- Mitochondrial internal viscosity impacts cellular transport and energy conversion.
- Existing viscosity probes lack specificity due to polar interference.
Purpose of the Study:
- To design and develop a novel, polar-insensitive fluorescent probe for accurate mitochondrial viscosity detection.
- To evaluate the probe's performance in vitro and in live cellular environments.
Main Methods:
- Synthesis of a novel phenothiazine-based fluorescent probe, Y-CN.
- Characterization of Y-CN's fluorescence response to varying viscosity levels (1.005–219 cP).
- Assessment of probe selectivity, pH stability, and cytotoxicity.
- In situ monitoring of mitochondrial viscosity changes in live cells.
Main Results:
- Y-CN demonstrated a strong linear correlation (R² > 0.99) between fluorescence intensity and viscosity.
- A significant 209-fold fluorescence amplification was observed with increasing viscosity.
- The probe exhibited high selectivity, pH stability, and low toxicity, and detected viscosity changes from food thickeners.
- Y-CN successfully monitored dynamic mitochondrial viscosity changes in live cells.
Conclusions:
- The novel polar-insensitive probe Y-CN provides a specific and sensitive method for measuring mitochondrial viscosity.
- Y-CN is a valuable tool for investigating mitochondria-associated physiological and pathological processes.
- This probe has significant potential for diverse biological and medical applications.
