Molecular visualizing and quantifying immune-associated peroxynitrite fluxes in phagocytes and mouse inflammation model

Abstract Reactions of peroxynitrite (ONOO − ) with biomolecules can lead to cytotoxic and cytoprotective events. Due to the difficulty of directly and unambiguously measuring its levels, most of the beneficial effects associated with ONOO − in vivo remain controversial or poorly characterized. Recently, optical imaging has served as a powerful noninvasive approach to studying ONOO − in living systems. However, ratiometric probes for ONOO − are currently lacking. Herein, we report the design, synthesis, and biological evaluation of F 482 , a novel fluorescence indicator that relies on ONOO − -induced diene oxidation. The remarkable sensitivity, selectivity, and photostability of F 482 enabled us to visualize basal ONOO − in immune-stimulated phagocyte cells and quantify its generation in phagosomes by high-throughput flow cytometry analysis. With the aid of in vivo ONOO − imaging in a mouse inflammation model assisted by F 482 , we envision that F 482 will find widespread applications in the study of the ONOO − biology associated with physiological and pathological processes in vitro and in vivo.