A mitochondria-targeting fluorescent Fe3+ probe and its application in labile Fe3+ monitoring via imaging and flow cytometry

Abstract The biogenesis of heme and iron-sulfur cluster in mitochondria is closely associated with the intracellular iron homeostasis. In this study, a mitochondria-targeting probe with the reversible turn-on fluorescent response to Fe3+ was developed for mitochondrial labile Fe3+ monitoring by modifying spirolactam rhodamine with a chelator. With this probe, the mitochondrial labile Fe3+ fluctuation in adherent cells upon ferric citrate incubation was visualzied via confocal imaging, and the flow cytometric assay for mitochondrial Fe3+ in suspension cells, which is difficult to be monitored via confocal imaging, was also developed. Moreover, the labile Fe3+ drop in mitochondria of K562 cells undergoing the DMSO-stimulated erythroid differentiation was observed for the first time.