A membrane-activatable near-infrared fluorescent probe with ultra-photostability for mitochondrial membrane potentials

Abstract

Mitochondrial membrane potential (MMP) is a frequently used indicator for mitochondrial function. Herein, we report a photostable near-infrared (NIR) fluorescent dye for monitoring MMP. This new probe, named NIMAP, is non-fluorescent in aqueous solution and can be activated by cell membranes, providing high fluorescence contrast and low background fluorescence. NIMAP has been validated for monitoring MMP in living mammalian cells and in mice. Due to the large fluorescence response, low fluorescence background, high photostability, and excellent tissue penetration resulting from red-shifted excitation and emission in the "optical window" above 600 nm, broad applications of this new probe are expected.

Organelle-Directed Staudinger Reaction Enabling Fluorescence-on Resolution of Mitochondrial Electropotentials via a Self-Immolative Charge Reversal Probe

“…Historically, distinct methods have been developed to detect altered ΔΨm including intraorganelle Click chemistry based mass spectrometry, the hetero-organelle partitioned sensors, , or fluorophores with potential-responsive properties. , In addition, ΔΨm manipulation has been achieved using photochemistry or metal catalysis. , In line with these approaches, this work developed a simplified method for facile fluorescence-on imaging of ΔΨm alteration by organelle-directed Staudinger reaction in living cells.…”

A Sensitive Near-Infrared Fluorescent Sensor for Mitochondrial Hydrogen Sulfide

“…To characterize the chemoselectivity of nimazide, we prepared liposomes as previously described. 22 Briefly, we vacuumed cholesterol (2.5 mg) and L-α-Lecithin egg yolk (10 mg) in chloroform: methanol (v/v 3: 2) on a rotary evaporator for 3 h to form a thin, oily film on the glass wall of the flask. Next, we added double distilled water (ddH 2 O, 1 mL) and continued the rotation of the rotary evaporator for another 15 min.…”

“…1a), derived from the dark quencher QSY-21, for monitoring mitochondrial membrane potentials in live cells. 22 The fluorescence of NIMAP is activatable by the lipid membrane, resulting in low fluorescence background and high fluorescence contrast. Because of a number of favorable features of NIMAP, including mitochondrial localization, high photostability, and near-infrared fluorescence, we therefore developed a novel fluorescent H 2 S probe based on the QSY-21 scaffold.…”

“…To reduce phototoxicity and increase tissue penetration, fluorescent probes with near-infrared absorption and emission are preferred . Our group previously reported a near-infrared fluorescent probe, NIMAP (Figure a), derived from the dark quencher QSY-21, for monitoring mitochondrial membrane potentials in live cells . The fluorescence of NIMAP is activatable by the lipid membrane, resulting in low fluorescence background and high fluorescence contrast.…”

Mitochondrial Chemical Biology: New Probes Elucidate the Secrets of the Powerhouse of the Cell

“…Recently, probes specialized for in vivo fluorescence imaging have been developed that utilize near-infrared (NIR) fluorescence approaches (Ren et al, 2015). The compound NIMAP, for example, was shown to exhibit fluorescence only when localized to the inner mitochondrial membrane in a highly potentialdependent manner (Ren et al, 2015). The NIR excitation wavelength allowed for efficient excitation of the fluorophore in deep tissues of mice injected subcutaneously with the compound.…”