Improvement of In Vitro Oocyte Maturation from Mice with Polycystic Ovary Syndrome by Co-Culture with Normal Granulosa Cell-Conditioned Media

Background: In the PCOS ovaries, growth of early follicles is mostly arrested. On the other, the outcome of in vitro matura-tion (IVM) of PCOS oocytes is poor. Because the oocytes are usually matured in vitro without cumulus cells. In this ways, the studies are focusing to optimize the culture maturation me-dia, and aid in the final stages of oocyte maturation in vitro. Therefore, the purpose of this study is to answer the following questions: Will there be a connection between normal cumulus-granulosa cells and germinal vesicle oocytes from mice with polycystic ovarian syndrome (PCOS) in co-culture medium How much will the connection between immature oocytes and cumulus-granulosa cells affect maturation rate of oocytes Materials and Methods: In this study, the cumulus and granu-losa cells were harvested from ovaries of normal NMRI mouse, and cultured for 24 hours in an IVM medium (minimum essen-tial medium: α-MEM) supplemented with 10% bovine serum albumin. Then, oocytes at germinal vesicle stages were harvested from PCOS mice (induced to estradiol valerate for 60 days), and incubated with cultured cumulus-granulosa cells for extra 24 hours. The maturation rate of the PCOS germinal vesicles was evaluated. The presence of connection between cultured intact cumulus-granulosa cells and PCOS oocytes studied using the scanning electron microscope (SEM) images. The viability of cumulus-granulosa cells was also assayed using trypan blue staining.Results: In the end of the 60-day treatment period, the fail-ure of estrous cycle, the presence of multiple cystic follicles, atretic follicles, degenerated granulosa cells and oocytes, and increased testosterone, progesterone and estradiol levels con-firm PCOS model. Data show that MII oocytes significantly (p < 0.05) increased in the presence of normal cumulus-granulosa cells when compared with the control group (cultured PCOS oocytes). In addition, the viability of cumulus-granulosa cells preserves during culture period. The SEM images shows the connection between normal cells and PCOS oocytes during cul-ture periods.Conclusion: The results of our study highlight the importance of maturation media formulations and culture protocols via co-culture of PCOS immature oocytes with intact cumulus-gran-ulosa cells to promote culture microenvironment for meiotic resumption.

کلیدواژه ها:

PCOS ، Co-Culture ، Cumulus-Granulosa Cells ، Ger-minal Vesicle ، IVM