Revealing Mitochondrion–Lysosome Dynamic Interactions and pH Variations in Live Cells with a pH-Sensitive Fluorescent Probe

Abstract

Mitochondrion−lysosome interactions have garnered significant attention in recent research. Numerous studies have shown that mitochondrion− lysosome interactions, including mitochondrion−lysosome contact (MLC) and mitophagy, are involved in various biological processes and pathological conditions. Single fluorescent probes are termed a pivotal chemical tool in unraveling the intricate spatiotemporal interorganelle interplay in live cells. However, current chemical tools are insufficient to deeply understand mitochondrion−lysosome dynamic interactions and related diseases, Moreover, the rational design of mitochondrion−lysosome dual-targeting fluorescent probes is intractable. Herein, we designed and synthesized a pH-sensitive fluorescent probe called INSA, which could simultaneously light up mitochondria (red emission) and lysosomes (green emission) for their internal pH differences. Employing INSA, we successfully recorded long-term dynamic interactions between lysosomes and mitochondria. More importantly, the increasing mitochondrion−lysosome interactions in ferroptotic cells were also revealed by INSA. Further, we observed pH variations in mitochondria and lysosomes during ferroptosis for the first time. In brief, this work not only introduced a pH-sensitive fluorescent probe INSA for the disclosure of the mitochondrion−lysosome dynamic interplays but also pioneered the visualization of the organellar pH alternation in a specific disease model.

A multipurpose mitochondrial NIR probe for imaging ferroptosis and mitophagy

“…It is expected that upon mitophagy, the damaged mitochondria are taken by the lysosomes for degradation. 59,60 NP was incubated in serum-free media along with Lysotracker blue (Fig. 8B), which visualizes lysosomes and NP shows mitochondrial selectivity at 0 minutes (Fig.…”

Monophenyl luminescent material with dual-state emission and pH sensitivity for cell imaging

“…5,6 Therefore, development of a tool that can effectively track changes in cellular lysosomal pH is essential for keeping track of the metabolic processes and cellular state of the cell. 2,[7][8][9] Various pH monitoring methods have been developed, including voltammetry, nuclear magnetic resonance (NMR), and spectrophotometry. 10 However, uorescence spectroscopy is the most widely used method due to its low cost, high sensitivity, fast response, simplicity of operation, and non-invasive detection.…”

“…5,6 Therefore, development of a tool that can effectively track changes in cellular lysosomal pH is essential for keeping track of the metabolic processes and cellular state of the cell. 2,7–9…”

Monitoring the Mitochondrial Viscosity Changes During Cuproptosis with Iridium(III) Complex Probe via In Situ Phosphorescence Lifetime Imaging

“…Fluorescence-based methods have emerged as powerful tools for detection of intracellular pH, polarity, and viscosity due to its inherent advantages simple implementation, noninvasiveness, and high sensitivity. − Although many fluorescent probes have been developed for monitoring the viscosity change in mitochondria, ,, most of them exhibited poor immobilization on mitochondria and cannot be used for quantitative measurement of viscosity. Therefore, it is a great challenge to develop a mitochondria targeting probe that can quantitatively measure the mitochondrial viscosity changes in situ for long time without off-target effect.…”