A mitochondrial-targeting near-infrared fluorescent probe for bioimaging and evaluating endogenous superoxide anion changes during ischemia/reperfusion injury

摘要

Abstract The outburst of superoxide anion (O 2 ? ) in mitochondrial during ischemia/reperfusion (I/R) process will cause a series of oxidative damage including polarity loss of mitochondrial membrane potential, overload of secondary cellular calcium, and cascade apoptosis. To monitor the O 2 ? level fluctuations as well as to evaluate the relationship between O 2 ? concentration and the degree of cell apoptosis during I/R process, we propose a ratiometric near-infrared mitochondrial targeting fluorescent probe Mito-Cy-Tfs for the detection of level changes of O 2 ? in cells and in?vivo . The probe Mito-Cy-Tfs is composed of three moieties: near-infrared heptamethine cyanine as fluorescence signal transducer, trifluoromethanesulfonamide as fluorescence modulator, and lipophilic triphenylphosphonium cation as mitochondrial guider. The probe can well locate in mitochondria and respond the concentration changes of endogenous O 2 ? selectively and sensitively. The probe has been successfully utilized to image the endogenous O 2 ? fluctuations in four kinds of cell I/R models (glucose deprivation/reperfusion, serum deprivation/reperfusion, oxygen deprivation/reperfusion and glucose-serum-oxygen deprivation/reperfusion). The probe also exhibits deep tissue penetration for real-time imaging of O 2 ? concentration in liver of I/R mice model. We confirm that the adoption of ischemic preconditioning (IPC) and postconditioning (IPTC) can protect liver from I/R injury. The probe can be employed to accurately indicate and evaluate the mutual relationship between the levels of O 2 ? and the degrees of organ damage during I/R, IPC and IPTC processes. The above applications make our new probe a potential candidate for the clinical surgery assessment. Highlights ? A mitochondrial-targeting near-infrared ratiometric fluorescent probe for bioimaging during ischemia/reperfusion (I/R) injury. ? The probe can be used to evaluate the burst of endogenous superoxide anion (O 2 . ? ) in mitochondria during cell I/R process. ? Further, to explore the relationship between O 2 . ? concentration and I/R injury degree. ? Ischemic preconditioning and postconditioning can limit the degree of liver I/R injury through the decrease of O 2 . ? burst.