Hot-Band Absorption of a Cationic RNA Probe Enables Visualization of ΔΨ_m via the Controllable Anti-Stokes Shift Emission

Abstract

Mitochondrial membrane potential (ΔΨ m ) is an important biophysical parameter playing central roles in cell apoptosis, mitochondrial dysfunction, and other biological and pathological processes. Herein, we have rationally designed and fabricated a unique fluorescent probe for convenient ΔΨ m visualization based on hot-band absorption and controllable anti-Stokes shift emission. The robust probe was excitable via hot-band absorption and emitted anti-Stokes upconversion emission and Stokes downconversion fluorescence simultaneously. The anti-Stokes emission could be efficiently inhibited upon the binding to RNA. The cationic probe targeted mitochondria in living cells with high ΔΨ m and displayed both anti-Stokes green emission and ordinary red fluorescence. After the decrease of ΔΨ m , the probe immigrated out of mitochondria to RNA and nucleolus, which showed only red emission owing to the inhibition of anti-Stokes fluorescence. In this manner, the ΔΨ m could be visualized in dual-color mode. The probe enabled clearly monitoring the reversible changes in ΔΨ m and was successfully employed to visualize oxidative damage of living cells. The decrease of ΔΨ m in living tissues was also successfully observed with the newly designed probe.

Investigating Oxidative Stress Associated with Myocardial Fibrosis by High-Fidelity Visualization and Accurate Evaluation of Mitochondrial GSH Levels

“…20 Therefore, a reversible probe for GSH with a suitable dissociation equilibrium constant (K d ) around the physiological concentration of mGSH is required. 21,22 It is well-known that the mitochondrial membrane potential (MMP) decreases or even disappears during oxidative stress, 23 which will cause the probe to leak from mitochondria. 24 capable of being unaffected by the MMP is clearly more suitable for the detection of oxidative stress.…”

“…On the other hand, given the cellular toxicity, the concentration of probes used for fluorescence imaging is usually much lower than the physiological concentration of GSH . Therefore, a reversible probe for GSH with a suitable dissociation equilibrium constant ( K d ) around the physiological concentration of mGSH is required. , It is well-known that the mitochondrial membrane potential (MMP) decreases or even disappears during oxidative stress, which will cause the probe to leak from mitochondria . Therefore, a fluorescent probe capable of being unaffected by the MMP is clearly more suitable for the detection of oxidative stress.…”

Construction of a Dual-Emissive Probe for Discriminative Visualization of Lysosomal and Mitochondrial Dysfunction

“…For example, Moritomo et al developed a cationic fluorescent probe with high affinity to DNA for the visualization of ΔΨ m and mitochondrial damage via its subcellular immigration . Yu and co-workers devoted several probes for ΔΨ m and particularly one of which could realize the observation of ΔΨ m and mitochondrial damage in the dual-color mode. , We have also constructed dual-emissive probes for mitochondrial depolarization and mPTP opening based on polarity-responsive mechanism, up-conversion fluorescence, aggregation mechanism, and pH-responsive principle in previous studies. – On the other hand, lysosomal damages are usually accompanied by the increase of lysosomal pH and the LMP procedure. Therefore, fluorescent probes responsive to lysosomal pH and LMP can detect lysosomal damage.…”