Ischemia is a pathological condition owing to the deficiency of blood supply to a limited area of tissue.
Ischemia can induce burst production of
reactive oxygen species and lead to oxidative damage. As a family member of reactive
sulfur species,
sulfane sulfur plays important physiological roles in many biological events including synthesis of cofactors, modulation of
enzyme activities, sulfuration of
tRNA, and especially regulation of the intracellular redox state. We hypothesize that the endogenous level of
sulfane sulfur will be adjusted to deal with
ischemia-induced oxidative damage. Therefore, the bioimaging of
sulfane sulfur real-time changes during
ischemia is important for better understanding its physiological processes. Herein, we describe the development of a mitochondria-targeted
fluorescent probe Mito-SH that allowed for selective and sensitive detection of
sulfane sulfur. Mito-SH is designed on the basis of the tautomerization of
sulfane sulfur to thiosulfoxide, which ensures its high selectivity and sensitivity. A lipophilic
triphenylphosphonium cation is selected as the mitochondria-targeted moiety, which can precisely navigate Mito-SH into mitochondria. The emission profile of azo-
BODIPY fluorophore locates at the near-infrared region, which deeply penetrates tissue and effectively avoids the interference of biological background. Mito-SH exhibits the desirable combination of selectivity, sensitivity and excellent fluorescence response upon reaction with
sulfane sulfur in cells. By employing Mito-SH, we evaluate the real-time
sulfane sulfur dynamic changes under
oxygen-
glucose deprivation. Finally, Mito-SH has been successfully used for imaging
sulfane sulfur changes caused by acute
ischemia in mice.