Major Epigenetic Changes in Polycystic Ovary Syndrome

Abstract

Introduction: Polycystic Ovary Syndrome (PCOS) is one of the most common causes of female infertility. The etiology of this condition is complex. Various genetic and environmental factors have been identified in the pathogenesis of PCOS. The prevalence of this syndrome among Iranian females has been reported between 7.1% to 14.6%. Common symptoms include irregular menstruation, infertility, ovarian cysts, acne, insulin resistance and obesity. This study was performed to collect and classify epigenetic changes in polycystic ovary syndrome. Conclusion: Epigenetic changes in PCOS could occur in two levels, including nucleus and mitochondrial level. The nuclear level consists of four categories. First, changes in DNA methylation, that could affect genes involved in signaling pathways, apoptosis and autophagy, hormone synthesis, oxidative phosphorylation, cell metabolism, ovulation, follicular angiogenesis, inflammation and immune system. The second category is changes in microRNAs, which have been reported to increase or decrease in tissues such as fat, serum, and follicle. The third category consists of changes in histone modifications such as acetylation and methylation. The last category affects chromatin remodeling that leads to alterations in structure of chromatin fibers. At the mitochondrial level, both the nuclear genes with crucial role in mitochondrial function and the genome of the organelle could be affected. In recent years, various epigenetic alterations have been identified among the patients with PCOS, however, still more studies are needed to find further Epimutations. Comprehensive studies should investigate the exact effects of these changes on the pathology of the disease in order to find epidrugs or environmental factors that can modify these alterations.