The Effects of Oxidative Stress on Endometriosis
Introduction. Endometriosis is a chronic disease in which uterine tissue is implanted outside of the uterus1. This disease affects one in every 10 women2. The risk of endometriosis increases with increasing ovulatory cycles; therefore, women with less pregnancies or irregular menstrual cycles may be at higher risk of developing the disease3. Endometriosis often presents as asymptomatic; however chronic pelvic pain, dysmenorrhea, dyspareunia, dyschezia, and subfertility are common symptoms that may indicate endometrial tissue development3. For diagnosis of endometriosis, surgical biopsy and pathological analysis are required2,4. However, pain levels as well as pelvic and transvaginal ultrasonography may give the physician some indication of the diagnosis2,4. Methods. Generation of reactive oxygen species (ROS) in endometrial tissue contributes to the inflammation experienced in endometriosis by forming DNA adducts as well as disulfide bonds between thiols1,5. Excess ROS produces oxidative stress and may be caused by an imbalance between oxidation and reduction enzymes1. Studies examined this shift between oxidative and antioxidant enzymes as well as the alteration of ROS production in mitochondria in endometrial tissue1,6. Other studies examined the relationship between oxidative stress produced in endometrial tissue and its contribution to infertility and tumorigenesis7,8. Results. Based on the results of the study, phase I (oxidative) CYP450 enzymes, specifically CYP1A1 and CYP3A7, showed an increase in endometrial tissue compared to normal tissue1. Furthermore, phase II (antioxidative) enzymes showed a decrease in endometrial tissue1. Mitochondria was also found to contribute to ROS production through mitochondrial elongation6. Oxidative stress produced by endometrial tissue demonstrated a decrease in tumor suppressor genes as well as antioxidant enzymes7. Finally, ROS exposure in endometrial granulosa cells induced senescence, inhibiting viability of these cells8. Conclusion. These results indicate the importance of antioxidant and oxidant enzyme levels in the contribution to excess ROS and resulting oxidative stress in endometriosis. This oxidative stress may have many adverse consequences, such as inflammation as well as contributions to tumorigenesis and infertility. Enzyme level regulation may offer one possible mechanism in which inflammation caused by endometriosis could be controlled. This potential treatment method offers hope in reducing pain associated with this chronic disease and warrants further exploration.
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- Chen C, Zhou Y, Hu C, et al. Mitochondria and oxidative stress in ovarian endometriosis. Free Radic Biol Med. 2019;136:22-34. https://doi.org/10.1016/j.freeradbiomed.2019.03.027. Accessed April 13, 2021.
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- Lin X, Dai Y, Tong X, et al. Excessive oxidative stress in cumulus granulosa cells induced cell senescence contributes to endometriosis-associated infertility. Redox Biol. 2020;30:101431. https://pubmed.ncbi.nlm.nih.gov/31972508/. Accessed April 13, 2021.