Fig. 1

The concept of the hierarchical oxidative stress response. In order to explain the observed effects in cells after exposure to DEPM, the concept of the hierarchical oxidative stress response was developed [23]. In this concept, the cellular response is divided in three different tiers, depending on the level of oxidative stress. In tier 1 the level of oxidative stress is moderate and cellular defense mechanisms are able to cope with the radicals. In tier 2 the level of oxidative stress causes already an inflammatory response and activation of cells. Finally, in tier 3 the oxidative stress leads to cytotoxicity and cellular damage (adapted and modified from [73])