A ratiometric fluorescent probe for imaging and quantifying anti-apoptotic effects of GSH under temperature stress.

Hypothermia and hyperthermia are cell stressed states resulting from environmental temperature changes, which can abnormally decrease intracellular glutathione (GSH) concentrations and induce apoptosis. As the most abundant intracellular non-protein biothiol, GSH can protect cells from apoptosis. Considering the important roles of GSH in the anti-apoptotic process in cells and in vivo, we strive to develop a powerful chemical tool for the direct detection of GSH concentration changes under temperature stress. Herein, we report a ratiometric fluorescent probe (CyO-Dise) based on a selenium-sulfur exchange reaction for the qualitative and quantitative detection of GSH concentration fluctuations in cells and in vivo. The probe has been successfully used to assess the changes of GSH levels in HepG2 and HL-7702 cells using the stimulations of hypothermia and hyperthermia. In terms of the anti-apoptotic effect of GSH under hypothermic and hyperthermic conditions, human normal liver HL-7702 cells have stronger abilities to fight against temperature stress than human liver carcinoma HepG2 cells. Hypothermia and hyperthermia can also improve the drug resistance of cis-dichlorodiamineplatinum(ii) (DDP)-resistant HepG2/DDP cells. The CyO-Dise probe has been employed to image GSH concentration changes in HepG2 and HepG2/DDP xenografts on nude mice. With the adjuvant therapy effects of hypothermia and hyperthermia, the chemotherapy drug DDP exhibits good ability for the treatment of HepG2 and HepG2/DDP xenografts. The above applications make our probe a potential new candidate for the accurate diagnosis of cancer and efficacy evaluation of treatment.

Fluorescent probes for hydrogen sulfide detection and bioimaging.

In comparison with other biological detection technologies, fluorescence bioimaging technology has become a powerful supporting tool for intracellular detection, and can provide attractive facilities for investigating physiological and pathological processes of interest with high spatial and temporal resolution, less invasiveness, and a rapid response. Due to the versatile roles of hydrogen sulfide (H2S) in cellular signal transduction and intracellular redox status regulation, fluorescent probes for the detection of this third signalling gasotransmitter have rapidly increased in number in recent years. These probes can offer powerful means to investigate the physiological actions of H2S in its native environments without disturbing its endogenous distribution. In this feature article, we address the synthesis and design strategies for the development of fluorescent probes for H2S based on the reaction type between H2S and the probes. Moreover, we also highlight fluorescent probes for other reactive sulfur species, such as sulfane sulfurs and SO2 derivatives.