Autophagy Contributes to the Maintenance of Genomic Integrity by Reducing Oxidative Stress

Figure 6

Oxidative stress mediates the elevation of MN caused by autophagy inhibition in MSCs. (a, b) Inhibition of autophagy increases ROS in MSCs. (a) MSCs were treated with CQ (50 μM) for 24 h. (b) MSCs were transfected with ATG5 siRNA or control-siRNA, and cells were harvested for examination 48 h later. Cellular ROS level was determined by flow cytometry. (c, d) NAC reduces the accumulation of DNA damage caused by autophagy inhibition. (c) MSCs were pretreated with or without the antioxidant NAC (5 mM) for 2 h and then treated with CQ (50 μM) for 24 h. (d) MSCs were transfected with ATG5-siRNA or control-siRNA and then treated with NAC (5 mM). The protein level of γ-H2AX was measured by Western blot analysis. (e, f) NAC attenuates MN elevation caused by autophagy inhibition. (e) MSCs were pretreated with or without the antioxidant NAC (5 mM) for 2 h and then treated with CQ (50 μM) for 24 h; cells were processed for examination of the frequency of MN at 48 h after drugs were washed out. (f) MSCs were transfected with ATG5-siRNA or control-siRNA and then treated with NAC (5 mM) 24 h later; cells were processed for examination of the frequency of MN at 48 h after drug was washed out. Each experiment was repeated three times. and . NAC: N-acetylcysteine.

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