Electrochemical Monitoring of ROS/RNS Homeostasis Within Individual Phagolysosomes Inside Single Macrophages

Angew Chem Int Ed Engl. 2019 Jun 3;58(23):7753-7756. doi: 10.1002/anie.201902734. Epub 2019 May 2.

Abstract

The existence of a homeostatic mechanism regulating reactive oxygen/nitrogen species (ROS/RNS) amounts inside phagolysosomes has been invoked to account for the efficiency of this process but could not be unambiguously documented. Now, intracellular electrochemical analysis with platinized nanowire electrodes (Pt-NWEs) allowed monitoring ROS/RNS effluxes with sub-millisecond resolution from individual phagolysosomes impacting onto the electrode inserted inside a living macrophage. This shows for the first time that the consumption of ROS/RNS by their oxidation at the nanoelectrode surface stimulates the production of significant ROS/RNS amounts inside phagolysosomes. These results establish the existence of the long-postulated ROS/RNS homeostasis and allows its kinetics and efficiency to be quantified. ROS/RNS concentrations may then be maintained at sufficiently high levels for sustaining proper pathogen digestion rates without endangering the macrophage internal structures.

Keywords: ROS/RNS production; homeostasis; nanoelectrode amperometry; phagolysosomes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cells, Cultured
  • Electrochemical Techniques / methods*
  • Electrodes*
  • Homeostasis*
  • Macrophages / cytology
  • Macrophages / metabolism*
  • Mice
  • Oxidation-Reduction
  • Phagosomes / metabolism*
  • Reactive Nitrogen Species / metabolism*
  • Reactive Oxygen Species / metabolism*

Substances

  • Reactive Nitrogen Species
  • Reactive Oxygen Species