Analysis of genomic damage in the lung exposed to endotoxin using immuno-spin trapping: mechanisms and therapies.

RAMIREZ DC; GOMEZ-MEJIBA S.E

SAN LUIS

Congreso; SBC; 2014

">To measure DNA radicalization we use the immuno-spin trapping assay with the nitrone spin trap 5,5-dimethyl-1-pyrroline ?N oxide (DMPO). Biochemical models showed that HOCl added as a bolus or continuously generated by myeloperoxidase(MPO) radicalizes purified DNA. Cell models showed that activated neutrophils can release MPO and epithelial cells can takeit up. MPO inside epithelial cells exposed to H2O2 and in activated neutrophils can produce HOCl that radicalize genomicDNA. In addition, by trapping DNA radicals downstream effects, such as formation of 8-oxo-dG and mutation of the HPRTgene were prevented. Biochemical and cell models also showed that resveratrol crosses easily cell membranes and reactsfaster with HOCl than with DNA and, thus protects against genotoxicity. In vivo models in mice shown that DMPO had aprotective effect against neutrophilic inflammation triggered by intratracheal instillation of LPS. This protection was morelikely due to interference with the retention of neutrophils caused by irritation of the airways by LPS. Indeed, DMPOinterferes with the NF-kB signaling pathway triggered by LPS, thus decreased expression of adhesion molecules and proinflammatiory cytokines. Homing/activation of neutrophils, intracellular HOCl production and DNA radicalization arepossible therapeutic targets against genotoxicity casued by neutrophilic inflammation of the airways.