P-190: Expression Changes of GDF- 9 and BMP-15 in The Oocytes of PCOS Patients Undergoing Treatment with N-acetylcysteine

Background: Polycystic ovary syndrome (PCOS) is a frustrating experience for women, considered as a complex challenge for researchers and clinicians. Despite the enormous effort to define the cause of PCOS, the etiology and pathogenesis still remain unclear. Oocyte quality is reflected in the oocyte’s intrinsic developmental potential. Studies have shown that the follicular development is disrupted in the PCOS ovaries, manifesting a large number of growing follicles arrested at a very early stage. Furthermore, data has demonstrated lower fertilization rate in PCOS patients indicating impaired oocyte and embryo development. BMP-15 and GDF-9, major oocyte secreted factors (OSFs), play a crucial role in follicular development, ovulation, oocyte maturation, and embryo development. GDF-9 and BMP-15 are members of the transforming growth factor b super family which are secreted from oocytes during folliculogenesis. They are essential for folliculogenesis and female fertility. The aim of this study was to investigate the effects of N-acetylcysteine (NAC) on the expression of GDF-9 and BMP- 15, markers of oocyte quality in human ICSI cycles. Materials and Methods: A prospective randomized, placebo controlled experimental study was conducted in the IVF/ ICSI Unit of infertility treatment center of the Qom. Total 40 cases between the age of 25 and 35 years with polycystic ovarian syndrome were selected and divided into two groups as follows (n=20): N-acetyl cysteine (treated with 600 mg NAC three times daily for six weeks) and placebo (group control). 40 oocytes (12 at the GV stage, 10 at the MI stage and 18 at the Unfertilized-MII stage) were obtained in control group and 30 oocytes (12 at the GV stage, 8 at the MI stage and 10 at the Unfertilized-MII stage) in NAC group. Oocytes were washed in PBS and transferred into RNase-free microcentrifuge tubes, followed by the addition of buffer RLT. Isolation of total RNA was performed by using the RNA mini-preps kit and the RNase-free DNase I set from the oocytes by using RT-PCR. Results: The expression level of GDF9 mRNA at the immature (GV+MI) and unfertilized-MII oocytes significantly increased in the NAC group in comparison with the control group. However, the expression level of BMP15 mRNA at the immature (GV+MI) and unfertilized- MII oocytes in the NAC group showed no significant difference in comparison with the control group. Conclusion: The low expression of oocyte secreted factors in the oocytes of PCOS patients might be associated with impaired oocyte quality; therefore NAC supplements can greatly improve the general quality of oocytes in PCOS patients.