Histone Methylation in the CYP11A1 Gene Promoter in the Follicular Granulosa Cells Extracted from the Women Referring to theFertility Treatment Clinic in Tabriz, Iran

Infertility is defined as the absence of pregnant after one year of regular unprotected sexual intercourse. In women, infertility may be caused by several factors, all of which may be affected by genetic factors. Epigenetic changes play a key role in embryonic development, ovulation, and spermatogenesis. During oocyte growth, follicular cells form a multilayer coating of granulosa cells, which are affected by gonadotropin hormones and secrete steroid hormones. TheCYP11A1gene is also involved in the pathway of steroid hormone production in luteinizing granulosa cells. The CYP11A1 enzyme converts cholesterol into pregnenolone in the progesterone production pathway. Progesterone is an important steroid hormone, which is significantly involved in fertility and pregnancy. Histone modifications also contribute to the induction of the CYP11A1gene, and methylation of histone H3 on lysine 4 (H3K4me) in the regulatory region of the gene leads to the increased expression and activation of gene transcription. The present study aimed to evaluate the methylation level of H3K4me3 in the CYP11A1 gene regulatory region in the granulosa cells extracted from the fertile and infertile women referring to the infertility treatment center in Tabriz, Iran. Chromatin immunoprecipitation (ChIP) and real-time polymerase chain reaction were used to evaluate the methylation level. According to the results, the fertile and infertile women had no significant difference in terms of the H3K4me3 methylation level at the CYP11A1 gene regulatory region. In addition, no significant correlations were observed between histone methylation at the CYP11A1 gene promoter region, follicle rate, and egg maturation.