DNA repair after oxidative stress: Current challenges

Model of how chronic ROS exposure provides a protective mechanism when cells are grown at intermittent low concentration (50 μM) of H2O2 and during prolonged periods (seven days). H2O2 molecules diffuse into the cell mediated by the aquaporin cell membrane protein, triggering two main cell responses: i) activating redox-sensitive mediators (e.g. PI3K/AKT, ERK1, SRC), and ii) inducing DDR through ATM and ATR sensors (red). Both signaling events promote transactivation of transcription factors augmenting gene expression of DNA repair enzymes, mainly of the BER pathway (blue), NER (green) and mismatch repair (black) converging in the ROS protective phenotype.285