Fluorescent probe for the imaging of superoxide and peroxynitrite during drug-induced liver injury†

Abstract

Drug-induced liver injury (DILI) is an important cause of potentially fatal liver disease. Herein, we report the development of a molecular probe (LW-OTf) for the detection and imaging of two biomarkers involved in DILI. Initially, primary reactive oxygen species (ROS) superoxide (O2˙−) selectively activates a near-infrared fluorescence (NIRF) output by generating fluorophore LW-OH. The C \n<svg xmlns= http://www.w3.org/2000/svg version= 1.0 width= 13.200000pt height= 16.000000pt viewBox= 0 0 13.200000 16.000000 preserveAspectRatio= xMidYMid meet ><metadata>\nCreated by potrace 1.16, written by Peter Selinger 2001-2019\n</metadata><g transform= translate(1.000000,15.000000) scale(0.017500,-0.017500) fill= currentColor stroke= none ><path d= M0 440 l0 -40 320 0 320 0 0 40 0 40 -320 0 -320 0 0 -40z M0 280 l0 -40 320 0 320 0 0 40 0 40 -320 0 -320 0 0 -40z /></g></svg>\n C linker of this hemicyanine fluorophore is subsequently oxidized by reactive nitrogen species (RNS) peroxynitrite (ONOO−), resulting in cleavage to release xanthene derivative LW-XTD, detected using two-photon excitation fluorescence (TPEF). An alternative fluorescence pathway can occur through cleavage of LW-OTf by ONOO− to non-fluorescent LW-XTD-OTf, which can react further with the second analyte O2˙− to produce the same LW-XTD fluorescent species. By combining NIRF and TPEF, LW-OTf is capable of differential and simultaneous detection of ROS and RNS in DILI using two optically orthogonal channels. Probe LW-OTf could be used to detect O2˙− or O2˙− and ONOO− in lysosomes stimulated by 2-methoxyestradiol (2-ME) or 2-ME and SIN-1 respectively. In addition, we were able to monitor the chemoprotective effects of tert-butylhydroxyanisole (BHA) against acetaminophen (APAP) toxicity in living HL-7702 cells. More importantly, TPEF and NIRF imaging confirmed an increase in levels of both O2˙− and ONOO− in mouse livers during APAP-induced DILI (confirmed by hematoxylin and eosin (H&E) staining).