A lipid droplet-targeting fluorescence probe for monitoring of lipid peroxidation in ferroptosis and non-alcoholic fatty liver disease

Abstract

Ferroptosis is a new regulated cell death process executed by lipid peroxidation (LPO) of polyunsaturated fatty acids. Lipid droplets (LDs), as an important organelle for lipid storage and metabolism, are probably a major site of LPO and play critical roles in the regulation of ferroptosis. However, the detailed study on LPO in LDs has not been carried out because of the lack of LD-targeting tools for the in situ monitoring of LPO. Herein, the first LD-targeting LPO fluorescence probe (LD-LPO) has been developed. LD-LPO exhibits a rapid and selective fluorescence enhancement at 518 nm, which is unaffected by highly destructive reactive oxygen species (e.g., hydroxyl radical) and environmental factor changes (e.g., polarity and viscosity). LD-LPO is capable of targeting LDs and visualizing LPO within LDs in situ during erastin- or (1S,3R)-RSL3 (RSL3)-induced ferroptosis. Moreover, LD-LPO has also been used to image LPO in the ferroptosis-associated non-alcoholic fatty liver disease (NAFLD), and to evaluate the medicine treatment of NAFLD with saroglitazar, demonstrating its utility for monitoring LPO levels in biosystems. The favorable analytical and imaging performance of LD-LPO may allow its application in more ferroptosis-associated physiological and pathological processes.