Rapid and specific fluorescent probe visualizes dynamic correlation of Cys and HClO in OGD/R

Intracellular redox homeostasis is of indispensable importance in pathophysiology. In order to maintain the balance of the redox state within the cell, reactive oxygen species (ROS) and reactive sulfur species (RSS) react and transform with each other, and their levels also directly reflect the degree of oxidative stress and disease. Hypochlorous acid (HClO) and cysteine (Cys) usually co-exist in organisms, interacting with each other in many important physiological processes and synergistically maintaining the dynamic redox balance in the body. To understand the relevance and pathophysiological effects of these two signaling molecules in oxidative stress, unique fluorescence imaging tools are required. Herein, we designed and developed a dual-channel fluorescent probe HP, for the individual and continuous detection of HClO and Cys. This probe could simultaneously monitor the changes in the concentrations of HClO and Cys in cells, and was characterized by a fast response, high sensitivity and high selectivity, especially compared with glutathione (GSH) and homocysteine (Hcy), the probe had a good specificity for Cys. Importantly, probe HP successfully observed dynamic changes in HClO- and Cys-mediated redox status in the oxygen-glucose deprivation/reperfusion (OGD/R) model of HeLa cells and dynamically monitored fluctuations in endogenous HClO levels in lipopolysaccharides (LPS)-induced peritonitis mice.