A two-photon fluorescent probe for visualizing endoplasmic reticulum peroxynitrite in Parkinson's disease models

Endoplasmic reticulum (ER) stress is implicated in the pathogenesis of diseases such as Parkinson's disease (PD). Peroxynitrite is the pivotal causative factor of ER stress. However, fluorescent probes for imaging the peroxynitrite in the ER are still lacking. In the present paper, we reported the design and synthesis of a two-photon fluorescence probe (ER-PN) for visualizing the ER peroxynitrite in PD models of living cells and C. elegans. ER-PN showed a rapidly and highly selective "turn-on" response to peroxynitrite over other biological species in vitro. Moreover, ER-PN showed excellent ER targeting ability and worked well in living systems for the ER peroxynitrite imaging. Noteworthy, ER-PN has been successfully applied for imaging the peroxynitrite in PD models, indicating its potential application for revealing the fundamental roles of peroxynitrite in ER stress-related diseases.