Figure 8.

Scheme illustrating how the side chain (SC) organization loss may be involved in a vicious circle of oxidative stress and energy failure. Reactive oxygen species (ROS) production by CI increases due to SC disassembly. Other mitochondrial events, such as membrane phospholipid peroxidation, mtDNA damage and subsequent misassembly of the respiratory complexes with further loss of SC organization, may occur due to the increased oxidative stress, thus fueling and maintaining the vicious circle. In a dose-dependent way, ROS can also operate as molecular signals from mitochondria to the nucleus. See text for explanations.