| Electrochemical Monitoring of ROS/RNS Homeostasis Within Individual Phagolysosomes Inside Single Macrophages Wei-hua Huang1; 1WUHAN UNIVERSITY, Wuhan, China; PAPER: 321/Oxidative/Regular (Oral) SCHEDULED: 16:45/Thu. 24 Oct. 2019/Zeus (55/Mezz. F) ABSTRACT: Reactive Oxygen/Nitrogen Species (ROS/RNS) produced by macrophages inside their phagolysosomes are closely related to immunity and inflammation by being involved in the removal of pathogens, altered cells, etc. The existence of a homeostatic mechanism regulating the ROS/RNS amounts inside phagolyso¬somes has been invoked to account for the efficiency of this crucial process, but this could never be unambiguously documented. Here, intracellular electrochemical analysis with platinized nanowires electrodes (Pt-NWEs) allowed monitoring of ROS/RNS effluxes with sub-millisecond resolution from individual phagolysosomes. These randomly impacted onto the electrode and were inserted inside a living macrophage. This evidenced 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 established the existence of the long-time postulated ROS/RNS homeostasis and allowed to quantify its kinetics and efficiency. ROS/RNS concentrations may then be maintained at sufficiently high levels for sustaining proper pathogen digestion rates without endangering the macrophage internal structures. References: [1] X. W. Zhang, Q. F. Qiu, H. Jiang, F. L. Zhang, Y. L. Liu, C. Amatore, W. H. Huang, Angew. Chem. Int. Ed. 56 (2017) 12997-13000. [2] X. W. Zhang, A. Oleinick, H. Jiang, Q. L. Liao, Q. F. Qiu, I. Svir, Y. L. Liu, C. Amatore, W. H. Huang, Angew. Chem. Int. Ed. 58 (2019) 7753-7756. |
