Figure 3.

Upregulation of Lon increases the level of mitochondrial ROS. (a) ROS generation in 293T cells exposed to hypoxia (1% O₂ for 24 h) were assessed using DCFDA staining and fluorescence intensity of the cells was measured in the presence or absence of NAC. (b) ROS generation in 293T cells overexpressing different amount of Lon as indicated were assessed using DCFDA staining and fluorescence intensity of the cells was measured. (c) Intracellular ROS generation by the cells overexpressing Lon was assessed using DCFDA staining in the presence or absence of NAC. The cell lines are as indicated. ROS level is presented as a ratio of fluorescence intensity of the stained cells and the buffer-only control. The error bars in graph indicate the S.E. from three independent experiments. *P<0.05, **P<0.01, and ***P<0.001. (d) Mitochondrial superoxide generation in 293 cells expressing Lon was assessed using MitoSox staining and fluorescence intensity of the cells was measured. (e) Mitochondrial superoxide generation in SCC-15 cells expressing vector or Lon-shRNA was assessed using MitoSox staining and fluorescence intensity of the cells was measured