Histone Methylation in StAR Gene Promoter Using Follicular Granulosa Cells Extracted from the Women Referring to a Fertility Clinic in Tabriz, Iran

Infertility is a disorder of the reproductive system, which often occurs after one year of regular unprotected intercourse with the aim of pregnancy. Several physical functions require the synthesis of steroid hormones, in which gonadal steroids (estrogen and progesterone) play a pivotal role in reproduction. Follicular growth and ovulation depend on the proliferation and differentiation of the granulosa and theca cells, which are possible in the steroid pathway after stimulation with the ovarian gonadotropins and cytokines. Steroidization is initiated with the transfer of cholesterol by the StAR protein to the mitochondrial membrane of the steroid cells, which is followed by a cascade of steroid hormones. Recent studies have highlighted the impact of epigenetic mechanisms on reproduction, emphasizing the importance of these changes in the early and secondary stages of gametogenesis. To determine the causes of infertility, it is essential to recognize the altered epigenetic modifications of the relevant gene and its mechanisms. In the present study, the H3K4me3 methylation level was evaluated in the StAR gene regulatory region in the granulosa cells collected from the fertile and infertile women referring to Tabriz Jihad Infertility Centerin Tabriz, Iran using ChIP-qPCR. According to the results, the H3K4me3 methylation level increased in the StAR gene regulatory region in the fertile women compared to the infertile women. In addition, a significant correlation was observed between the follicle and egg rates at the MII stage and the level of this methylation.