Trapping DNA-Centered Radicals Prevents Genotoxicity: An In Vitro Model.

LOPEZ CM;; FLORENCIA NAHIR CLAVELES CASAS,; BARRERAS, FS; DI SCIULLO MP,; DARIO RAMIREZ |; GOMEZ MEJIBA, SANDRA;

GEORGIA

Congreso; Free radical biology and medicine.; 2020

Free radical biology and medicine.

Neutrophilic inflammation (NI) is a tissueresponse to irritation that can lead to mutations. NI involvesneutrophil activation at irritated sites where myeloperoxidase(MPO) is released and taken up by surrounding cells. Insidecells, and in the presence of H2O2, HOCl is formed, butwhether it can cause genotoxicity is partially known.Objective: Herein we aimed at showing whetherintracellularly produced HOCl can cause mutation in airwayepithelial cells using an in vitro model. Method: Human A549lung epithelial cells were either incubated with highly purifiedhuman MPO and then exposed to H2O2, or they were coculturedwith a phorbol ester-activated human neutrophils.Results: Added or neutrophil released MPO was taken up byA549 cells. When exposed to H2O2 added as a bolus orgenerated by the glucose/glucose oxidase system, HOClwas intracellularly produced causing 8-oxo-dG formation,fosfo-p53 translocation into de nucleus, and mutation ofthe hypoxanthine phosphorybosyl transferase gene. Theseeffects were prevented when cells where incubated with either a cell permeable MPO inhibitor (ABAH), a scavengerof HOCl (resveratrol) or when the nitrone spin trap 5,5-dimethyl-1-pyrrline N-oxide was added before H2O2 addition.Conclusion: These data suggest that DNA-radicalizationcaused by HOCl precedes 8-oxo-dG formation andmutagenesis. Supported by: PICT-2018-3435 / PIP916 /PROICO100218 and 023418 / PUE 013 IMIBIO-SL.