Quantification of intracellular ROS levels
Intracellular ROS levels were measured using the membrane-permeable CellROX Deep Red reagent (Invitrogen Life Technologies), as described before [33]. Signal acquisition was performed an Arrayscan XTI automated workstation fitted with a 20x objective (Thermo Scientific, Courtaboeuf, France). Cellular fluorescence intensity levels were estimated with the HCStudio software [30].