A lysosome-located and rhodamine-based fluorescence probe for recognizing hydrogen polysulfide.

Hydrogen polysulfide (H2Sn, n≥2), as a kind of active sulfur species (RSS), has become a hot topic in RSS. It can regulate the biological activity of many proteins through S-sulfhydrylation of cysteine residues (protein Cys-SSH), and has a protective effect on cells. Although there have been some studies on hydrogen polysulfide, its production, degradation pathway and regulation mechanism still need further be researched. In presented study, an original lysosome-localized fluorescent probe for determining H2Sn was developed utilizing rhodamine as the fluorogen. The probe used morpholine as the locating unit of lysosomes and chose 2-fluoro-5-nitrobenzoate as the recognizing group. Before adding H2Sn, the proposed probe displayed a spironolactone structure and emitted very weak fluorescence. After adding H2Sn, a conjugated xanthene was formed and the probe demonstrated green fluorescence. When the H2Sn concentration was varied from 6.0×10-7 mol·L-1 to 10.0×10-5 mol·L-1, the fluorescence intensity of the probe was linearly dependent on the H2Sn concentration. And the detection limit was 1.5×10-7 mol·L-1. The presented probe owned a fast response speed, good selectivity, excellent sensitivity and broad pH work scope. In addition, the probe had been well utilized to sense endogenic and exogenic H2Sn in lysosomes.

An ICT-FRET-based ratiometric fluorescent probe for hydrogen polysulfide based on a coumarin-naphthalimide derivative.

Hydrogen polysulfide (H2Sn, n > 1), as one of the important members of reactive sulfur species (RSS), plays a vital part in the processes of both their physiology and pathology. In this work, a ratiometric fluorescent probe for H2Sn had been designed and prepared based on the combination mechanism of intramolecular charge transfer (ICT) and fluorescence resonance energy transfer (FRET). The probe chose a coumarin derivative as the energy donor, a naphthalimide derivative as the energy acceptor and 2-fluoro-5-nitrobenzoate as the H2Sn recognition group. When H2Sn was not present in the system, the ICT process of the naphthalimide acceptor was inhibited and the FRET process from the coumarin donor to the naphthalimide acceptor was turned off. When H2Sn was added, both ICT and FRET occurred due to the nucleophilic substitution-cyclization reactions between the probe and hydrogen polysulfide. In addition, the ratio value of the emission intensities at 550 nm and 473 nm (I550 nm/I473 nm) of this probe had a good linear relationship with H2Sn concentration in the range of 6.0 × 10-7-5.0 × 10-5 mol·L-1, and a detection limit of 1.8 × 10-7 mol·L-1 was obtained. The developed probe had high selectivity and sensitivity, as well as good biocompatibility. Additionally, the probe had been used to successfully image both indigenous and exogenous hydrogen polysulfide in A549 cells using confocal microscope.

Discovery of a triphenylamine-benzofuran derivative as fluorescent probe for hydrogen polysulfide in tea samples.

In this work, a novel triphenylamine-benzofuran derived fluorescent probe, TBF-SS, was developed for detecting hydrogen polysulfide in tea samples and intracellular imaging. TBF-SS showed the practical advantages including high sensitivity (LOD = 0.01 µM), high selectivity, rapid response (within 15 min), and steadiness in various environmental conditions. The detecting system was steady within pH range of 6.0-11.0 and temperature range of 20-55 °C. The probe TBF-SS could guarantee the stable detection of H2Sn for 7 d in storage of either solid or solution. In particular, in the application of various tea samples with different brewing times and testing temperatures, the recovery percentages varied in the range of 95.22 % to 105.0 %. Therefore accurate monitoring of H2Sn could be achieved by using the probe TBF-SS. In addition, TBF-SS could monitor the exogenous level, the ß-lapachone-induced generation and the tea-sample-treated introduction of H2Sn in living MCF-7 cells. This work might inspire the improvement of the serviceability of fluorescent implements.

Advances in fluorescence probes for detection of hydrogen polysulfides / 中国药科大学学报

@#Sulfane sulfur species in the reactive sulfur species family include hydrogen polysulfides (H2Sn, n ≥2), which play an essential role in physiological regulation and signal transduction. As a redox pair of H2S, H2Sn can be produced through oxidation or enzyme reaction and regulate protein interaction and enzyme activity.Research has revealed that H2Sn, with higher efficiency of protein S-sulfhydration than H2S, may be responsible for some physiological functions previously attributed to H2S.Therefore, real-time detection of H2Sn is crucial for studying its physiological activity and the relationship between H2S and H2Sn.Traditional detection methods, such as mass spectrometry, are not suitable for living organisms as they require tissue cell disruption.Instead, fluorescence probes are often used for in situ real-time detection due to their high sensitivity and specificity and low biological toxicity.This review summarizes the physiological regulatory activity of H2Sn, as well as the design strategy, response mechanism, fluorescence characteristics, and biological applications of H2Sn fluorescent probes based on the structure of the response group, with a prospect of the challenges and developments in this field.

A fluorescent probe derived from Berberrubine for detecting hydrogen polysulfide in food samples.

In this work, we chose the fluorophore Berberrubine to develop a selective probe for hydrogen polysulfide (H2Sn), and applied it into the detection in both food samples and living cells. The developed probe, HER9SS, suggested practical steadiness and serviceability, especially for multi-scene detection. The detecting system was stable in relatively wide pH (7.0-11.0) and temperature (25-45 °C) ranges. Both the storage of BER9SS in solid or in solution could maintain the steadiness over 7 d. BER9SS also indicated advantages including rapid response (within 15 min), high sensitivity (LOD = 0.02 µM; LOQ = 0.01 µM), long linear range (0-15.0 equivalent) and high selectivity among competing analytes. The recovery ranging in 95.23% - 104.8% in the applications in food sources samples (including water and plants) and food samples inferred the practical potential of BER9SS. In biological imaging, BER9SS could achieve both the dose-dependent monitoring and the ß-lapachone-induced generation of H2Sn. Therefore, the information in this work might be useful for the development of fluorescent probes from natural products for multi-scene applications in future, especially with the corresponding attentions on the practicability and serviceability.

Monitoring hydrogen polysulfide during ferroptosis with a two-photon fluorescent probe.

Hydrogen polysulfide (H2Sn, n > 1), a member of reactive sulfur species (RSS), is primarily generated during the crosstalk between H2S and reactive oxygen species (ROS), which plays important role in physiological and pathological processes. Ferroptosis is a new non-classical mode of cell death, in which ROS-associated lipid peroxidation and iron-dependent accumulation are the main features. However, the biological effects of H2Sn on ferroptosis and the detailed mechanisms of action remain poorly understood. Thus, there is an urgent need to develop highly selective and sensitive chemical tools for monitoring H2Sn in living cells. Herein, we develop a two-photon fluorescent probe (PSP) for specifically imaging H2Sn in live cells and tumor spheroids. This probe exhibited a sensitive and selective response to H2Sn, which had been used for imaging exogenous and endogenous H2Sn in living cells by confocal imaging and high content imaging. PSP exhibits excellent photo-stability and two-photon imaging performance when irradiating at 880 nm in 3D HeLa multicellular tumor spheroids. Importantly, our studies revealed that H2Sn levels were significantly up-regulated during ferroptosis. These excellent properties ensure that PSP is a promising two-photon probe for exploring the biological and pathological effects of H2Sn during ferroptosis.

A semi-naphthorhodafluor-based red-emitting fluorescent probe for tracking of hydrogen polysulfide in living cells and zebrafish.

Hydrogen polysulfides (H2Sn, n ≥ 2) is recently regarded as a potential signaling molecule which shows a higher efficiency than hydrogen sulfides (H2S) in regulating enzymes and ion channels. However, the development of specific fluorescent probes for H2Sn with long-wavelength emission (>600 nm) are still rare. In this work, a semi-naphthorhodafluor-based red-emitting fluorescent probe SNARF-H2Sn containing a phenyl 2-(benzoylthio) benzoate responsive unit was constructed. SNARF-H2Sn was capable of selectively detecting H2Sn over other reactive sulfur species. Treatment with H2Sn would result in a > 1000-fold fluorescence enhancement within 10 min. SNARF-H2Sn showed a low limit of detection down to 6.7 nM, and further enabled to visualize exogenous/endogenous H2Sn in living A549 cells and zebrafish.

Prodrugs of Persulfides, Sulfur Dioxide, and Carbon Disulfide: Important Tools for Studying Sulfur Signaling at Various Oxidation States.

Significance: Bioactive sulfur species such as hydrogen sulfide (H2S), persulfide species (R-SnSH, n ≥ 1), hydrogen polysulfide (H2Sn, n ≥ 2), sulfur dioxide (SO2), and carbon disulfide (CS2) participate in various physiological and/or pathological pathways such as vasodilation, apoptosis, inflammation, and energy metabolism regulation. The oxidation state of the individual sulfur species endows them unique biological activities. Recent Advances: There have been great strides made in achieving molecular understanding of the sulfur-signaling processes. Critical Issues: The development of various chemical tools that deliver reactive sulfur species in a controllable manner has played an important role in understanding the different roles of various sulfur species. In this review, we focus on three types of sulfur species, including persulfide, SO2, and CS2. Starting with a brief introduction of their physiological functions, we will then assess the various drug delivery strategies to generate persulfide species, SO2, and CS2 as research tools and potentially as therapeutic agents. Future Directions: Development of donors of various sulfur species that respond to distinct stimulus is critical for this field. Another key to the long-term success of this field is the identification of an area of unmet medical need that can be addressed with these sulfur species.

Protective Smell of Hydrogen Sulfide and Polysulfide in Cisplatin-Induced Nephrotoxicity.

Though historically known as a toxic gas, hydrogen sulfide (H2S) has displayed a new face as the third endogenous gaseous signaling molecule after nitric oxide (NO) and carbon monoxide (CO). Here in this review, we survey the role and therapeutic potential of H2S in cisplatin-induced nephrotoxicity. Specifically, reduction of H2S by cystathionine γ-lyase (CSE) downregulation upon cisplatin treatment may contribute to cisplatin-induced renal cell injury, possibly by augmentation of endogenous reactive oxygen species (ROS) production, while H2S donation may prevent subsequent renal dysfunction by inhibiting NADPH oxidase activation. Intriguingly, H2S slow-releasing compound GYY4137 seems to increase the anticancer activity of cisplatin, at least in several cancer cell lines, and this is probably due to its own anticancer effect. However, the efficacy of H2S donors in tumor-bearing animals remains to be tested in terms of renal protection and cancer inhibition after receiving cisplatin. Furthermore, accumulative evidence regarding usage of polysulfide, a novel H2S derived molecule, in the therapy of cisplatin-induced nephrotoxicity, was also summarized.

Photostable Ratiometric Two-Photon Fluorescent Probe for Visualizing Hydrogen Polysulfide in Mitochondria and Its Application.

Hydrogen polysulfide (H2Sn) has currently attracted much research interest because it not only plays an important physiological function in many biological and health-related events, but also is considered as a newfound potent signal transducer. Small-molecule-based ratiometric fluorescent probes have advantages in sensitivity and biodetection, but such approaches that are intentionally developed for H2Sn detection and expected to be mitochondria-accessible are still lacking. In this work, because of the triphenylphosphine group introduced into the molecular scaffold of the naphthalimide derivative, Mito-NRT-HP was successfully applied to visualize intracellular H2Sn in mitochondria with excellent aqueous solubility, super photobleaching resistance, favorable cellular membrane permeability, and good biocompatibility. This one- and two-photon fluorescent probe with high selectivity and sensitivity (limit of detection, LOD = 0.01 µM) evinced a 70-fold enhancement of the fluorescence ratio (I546nm/I478nm) in the presence of H2Sn over other reactive sulfur species (RSS). The experimental results also give Mito-NRT-HP the potential for mapping the H2Sn distribution in mitochondria and evaluating the H2Sn roles in more biological processes, and they demonstrated the practical application possibility of Mito-NRT-HP in the early diagnosis of lipopolysaccharide-induced (LPS-induced) acute organ injury.

Mitochondrial Specific H2S n Fluorogenic Probe for Live Cell Imaging by Rational Utilization of a Dual-Functional-Photocage Group.

Reactive sulfur species play a very important role in modulating neural signal transmission. Hydrogen polysulfides (H2S n, n > 1) are recently suggested to be the actual signaling molecules. There are still few spatiotemporal controllable-based probes to detect H2S n. In this work, for the first time, we proposed the photocleavage product of the common photoremovable protecting group (2-nitrophenyl moiety) capable of trapping H2S n. Taking advantage of this, we constructed the probe H1 containing a photocontrollable group, a mitochondrial directing unit and a signal reporter fluorescein dye. H1 exhibited excellent fluorescence enhancement (50-fold) in response to H2S n under the aqueous buffer only after UV irradiation. H1 also showed high selectivity and sensitivity for H2S n over other reactive sulfur species, reactive oxygen species, and other analytes, especially biothoils including hydrogen sulfide, cysteine, homocysteine, and glutathione. We showed the utility of H1 to image H2S n in living cells with high spatiotemporal resolution.