Abstract
The role of adipokines in ovarian-related disorders such as polycystic ovary syndrome (PCOS) has been reported. However, the involvement of Oncostatin M (OSM), a recently identified adipokine, in ovarian function is unknown. Therefore, we investigated the association of the OSM signaling pathway with ovarian functions and PCOS pathogenesis. This case-control study enrolled 30 PCOS and 30 healthy women who underwent the intracytoplasmic sperm injection procedure. OSM and OSM receptor (OSMR) levels were evaluated in the follicular fluid (FF). Moreover, the expression of insulin receptor substrates (IRS1 and IRS2), OSM, OSMR, suppressor of cytokine signaling 3 (SOCS3), and androgen receptor (AR) genes were analyzed in the isolated cumulus cells (CCs). For the in-vitro experiment, the effect of recombinant OSM on the expression of related genes in isolated CCs was analyzed. Follicular concentrations of OSM and OSMR were significantly lower in PCOS (123.91±48.58 pg/ml and 0.93±0.35 ng/ml, respectively) compared to control women (283.53 ± 96.62 pg/ml and 1.45 ± 0.18 ng/ml, respectively; p < 0.001) and were positively correlated with the oocyte maturation (r = 0.611 and r = 0.611, respectively) and fertilization (r = 0.592 and r = 0.627, respectively) rates in the PCOS group. Furthermore, the SOCS3 expression was upregulated about eight times in PCOS patients compared to the controls (p < 0.05). The treatment of cells with recombinant OSM significantly increased SOCS3, OSMR, IRS-1, and -2 expression and decreased AR expression. The decreased levels of OSM and its receptor in PCOS patients, possibly mediated by SOCS3, could negatively affect oocyte maturation and fertilization rates.