Evaluating visually a new apoptosis-induced reagent by a ratiometric two-photon fluorescent pH probe

Abstract

The level of apoptosis is directly related to the occurrence of cancer and other diseases. Real-time continuous monitoring of apoptotic process of living cells has great potential for early diagnosis of related diseases, as well as evaluation of therapeutic effect and screening of apoptotic drugs. This work proposed a ratiometric two-photon fluorescent probe Lyso-PCE equipped with a dual-function pyridine, as a pH-sensitive and specific lysosome-targeted group. A clear linearity relationship between two-channel fluorescence intensity ratios of Lyso-PCE and pH values was established in both solutions and living cells. Thanks to its ability of quantitative detection of pH, probe Lyso-PCE can detect the dynamic pH changes of lysosomes treated by chloroquine, and also can be used to in situ monitor dexamethasone-induced apoptosis. More importantly, reagent potassium bisperoxo (1,10-phenanthroline) oxovanadate (bpV(phen)) was evaluated and testified as a new apoptotic drug by Lyso-PCE, and the real-time visualization of bpV(phen)-induced apoptosis was realized under two-photon excitation. Our results provide a new and promising strategy for evaluating and screening apoptosis-related drugs.