Mitochondria and oxidative stress in ovarian endometriosis.

Endometriosis is associated with inflammatory reaction, and reactive oxidative species (ROS) are highly pro-inflammatory factors. Mitochondria are responsible for the production of ROS and energy. However, little is known about how mitochondria regulate ROS generation and energy metabolism in endometriosis. In our study, we investigated mitochondrial structure and function of ectopic endometrial stromal cells (ESCs) in ovarian endometriosis. We found mitochondria in ectopic ESCs generated more ROS and energy than controlled groups. Mitochondrial superoxide dismutase (SOD2), as an antioxidant enzyme, was found highly expressed in ectopic endometrium compared with normal endometrium. Due to its antioxidant role, SOD2 promoted the development of endometriosis by maintaining functional mitochondria to support high energetic metabolism of ectopic ESCs. We also showed that SOD2 promoted cell proliferation and migration in ovarian endometriosis. Inhibiting SOD2 expression reduced proliferation and migration of ectopic ESCS, and increased cell apoptosis. Therefore, understanding the role of mitochondrial dysfunction and SOD2 in ovarian endometriosis may provide new strategies to treat this disease.