Two-photon visualization of lysosomes-specific ferroptosis by a dual-functional fluorescent probe

Abstract

Ferroptosis is an iron-driven programmed cell death characterized by lipid peroxidation, and lysosomes are organelles abundant with iron species and highly associated with ferroptosis, thus it is of great significance to study the lysosomes-specific ferroptosis process. In this work, a novel dual-functional two-photon fluorescent probe Lyso-FNN with lysosomes-locating property is presented. By virtue of the dual intramolecular charge transfer (ICT) systems as well as the indole moiety as a pH response site in the structure, the probe can simultaneously respond to polarity and pH variations. Lyso-FNN was used successfully to monitor the fluctuations in lysosomal polarity and pH under two-photon excitation. Moreover, real-time two-photon fluorescence visualization of lysosomes-specific ferroptosis was realized through the dual-channel imaging of Lyso-FNN, and our findings revealed that the ferroptosis induced by erastin/RSL3 in HeLa cells was accompanied by an increase of lysosomal polarity and acidity. Notably, the capability of artesunate to induce the lysosomes-specific ferroptosis was evaluated by dual-color imaging of Lyso-FNN as well as the results of western blot. This study provides us a powerful tool to study the interrelation between ferroptosis and lysosomes, and to gain deeper understanding of lysosomes-specific ferroptosis process.