FIGURE 6.

MAO-B inhibition reduces mitochondrial dysfunction in response to H₂O₂ in myotubes from DMD patients. DMD or HD myotubes (from primary and immortalized cells) were exposed to H₂O₂ (100 μM) in the absence or presence of 1 μM safinamide, as a 20 min pre-treatment and then loaded with TMRM (25 nM) to monitor the mitochondrial membrane potential ΔΨm. (A) Representative kinetics of TMRM fluorescence intensity in one experiment with primary myotubes from patient DMD2. Single data points are the average of at least 15 individual myotubes. When indicated, FCCP (4 μM) was added to collapse ΔΨm. In the absence of safinamide, H₂O₂ treatment caused a drastic drop in the initial membrane potential, which led to a small difference in ΔΨm before and after FCCP. (B–F) Charts representing the variation in TMRM fluorescence intensities obtained in each condition before and after FCCP; one chart per cell type. Values in Y axis are expressed as percentage, considering the value in untreated cells as 100%. Each cell type was analyzed in two independent experiments. ^∗p < 0.05.