Real-Time Monitoring of Mitochondrial Damage Using Conjugated Oligoelectrolytes

J Am Chem Soc. 2024 Jan 10;146(1):660-667. doi: 10.1021/jacs.3c10531. Epub 2023 Dec 22.

Abstract

Conjugated oligoelectrolytes (COEs) comprise a class of fluorescent reporters with tunable optical properties and lipid bilayer affinity. These molecules have proven effective in a range of bioimaging applications; however, their use in characterizing specific subcellular structures remains restricted. Such capabilities would broaden COE applications to understand cellular dysfunction, cell communication, and the targets of different pharmaceutical agents. Here, we disclose a novel COE derivative, COE-CN, which enables the visualization of mitochondria, including morphological changes and lysosomal fusion upon treatment with depolarizing agents. COE-CN is characterized by the presence of imidazolium solubilizing groups and an optically active cyanovinyl-linked distyrylbenzene core with intramolecular charge-transfer characteristics. Our current understanding is that the relatively shorter molecular length of COE-CN leads to weaker binding within lipid bilayer membranes, which allows sampling of internal cellular structures and ultimately to different localization relative to elongated COEs. As a means of practical demonstration, COE-CN can be used to diagnose cells with damaged mitochondria via flow cytometry. Coupled with an elongated COE that does not translocate upon depolarization, changes in ratiometric fluorescence intensity can be used to monitor mitochondrial membrane potential disruption, demonstrating the potential for use in diagnostic assays.

MeSH terms

  • Coloring Agents
  • Electrolytes* / chemistry
  • Flow Cytometry
  • Lipid Bilayers* / chemistry

Substances

  • Lipid Bilayers
  • Electrolytes
  • Coloring Agents