Imaging of Endogenous Hydrogen Peroxide during the Process of Cell Mitosis and Mouse Brain Development with a Near-Infrared Ratiometric Fluorescent Probe

Hydrogen peroxide (H₂O₂) is emerging as a new second messenger, which plays vital roles in intracellular signaling, thereby triggering physiological variations in terms of proliferation, differentiation, and migration. As known, cell mitosis has close association to the intracellular level of H₂O₂, which contribute to the significant effects on brain development, especially during the critical period of immaturity. Unfortunately, imaging H₂O₂ in a mammalian brain is still challenging. Herein, to further investigate the biological roles of endogenous H₂O₂ in cell mitosis, we develop a near-infrared ratiometric fluorescent probe Cy-PFS for specifically imaging endogenous H₂O₂ in cells and in vivo. Employing the probe Cy-PFS, we examine the critical effects of endogenous H₂O₂ on proliferation of cells in live hippocampal neurons cells, and our results provide strong evidence for H₂O₂ signaling in cell mitosis through growth factor signaling. Furthermore, we successfully demonstrate the close association of endogenous H₂O₂ level changes with the brain development at various stages. We envision that this present probe has potential as a promising useful chemical imaging tool for exploring the roles of H₂O₂ in cell mitosis.