Optimal management of subfertility in polycystic ovary syndrome

Protective effect of propofol via the regulation of ovarian granulosa cell proliferation and apoptosis

Propofol is an anesthetic frequently used in surgery. Accumulating evidence suggests that propofol exhibits an effect on cell viability, apoptosis and invasion in several types of cancer cells. MicroRNAs (miRNAs) have been reported to play pivotal roles in the development of polycystic ovary syndrome (PCOS). However, the diagnostic applications of miR-451a in PCOS remain unknown. The present study aimed to elucidate the effects of propofol on ovarian granulosa cell proliferation and apoptosis and illustrate the specific mechanisms associated with this process. Human ovarian granulosa cell-like KGN cells, which were used as a representative of granulosa cells in the present study, were treated with different concentrations (0, 1, 5 and 10 µg/ml) of propofol for 48 h and cell proliferation and apoptosis were assessed using MTT and flow cytometry assays, respectively. Propofol treatment resulted in significant inhibition of cell viability and induction of apoptosis in KGN cells, which was accompanied with increased cleaved caspase 3 and suppressed pro-caspase 3 expression levels. Furthermore, propofol reduced Wnt3a and β-catenin protein and mRNA expression levels. miR-451a expression in KGN cells was evaluated by reverse transcription-quantitative PCR (RT-qPCR). miR-451a expression was upregulated in propofol-stimulated KGN cells. The data further demonstrated that miR-451a mimics suppressed cell proliferation and increased apoptosis of KGN cells compared with cells transfected with control mimics. Furthermore, the association between miR-451a and propofol was investigated. Rescue experiments were performed to investigate the anti-proliferative mechanism of propofol in ovarian granulosa cells. KGN cells were transfected with miR-451a inhibitor or inhibitor control sequences for 6 h and treated with 10 µg/ml propofol for an additional 48 h. The results from the MTT, RT-qPCR and western blot assays indicated that 10 µg/ml propofol inhibited cell viability, induced apoptosis, enhanced cleaved caspase 3 expression, reduced pro-caspase 3 levels and inhibited the protein and mRNA expression of Wnt3a and β-catenin. However, inhibition of miR-451a demonstrated the opposite effects. In conclusion, the results of the present study revealed that propofol exerted an anti-proliferative and apoptosis-inducing role in ovarian granulosa cells through mediation of miR-451a expression. In addition, the data indicated that miR-451a may be used as an effective therapeutic target for PCOS treatment.

Molecular Mechanisms of Laparoscopic Ovarian Drilling and Its Therapeutic Effects in Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) is a common endocrinopathy, characterized by chronic anovulation, hyperandrogenism, and multiple small subcapsular cystic follicles in the ovary during ultrasonography, and affects 5–10% of women of reproductive age. PCOS is frequently associated with insulin resistance (IR) accompanied by compensatory hyperinsulinemia and, therefore, presents an increased risk of type 2 diabetes mellitus (DM). The pathophysiology of PCOS is unclear, and many hypotheses have been proposed. Among these hypotheses, IR and hyperandrogenism may be the two key factors. The first line of treatment in PCOS includes lifestyle changes and body weight reduction. Achieving a 5–15% body weight reduction may improve IR and PCOS-associated hormonal abnormalities. For women who desire pregnancy, clomiphene citrate (CC) is the front-line treatment for ovulation induction. Twenty five percent of women may fail to ovulate spontaneously after three cycles of CC treatment, which is called CC-resistant PCOS. For CC-resistant PCOS women, there are many strategies to improve ovulation rate, including medical treatment and surgical approaches. Among the various surgical approaches, one particular surgical method, called laparoscopic ovarian drilling (LOD), has been proposed as an alternative treatment. LOD results in an overall spontaneous ovulation rate of 30–90% and final pregnancy rates of 13–88%. These benefits are more significant for women with CC-resistant PCOS. Although the intra- and post-operative complications and sequelae are always important, we believe that a better understanding of the pathophysiological changes and/or molecular mechanisms after LOD may provide a rationale for this procedure. LOD, mediated mainly by thermal effects, produces a series of morphological and biochemical changes. These changes include the formation of artificial holes in the very thick cortical wall, loosening of the dense and hard cortical wall, destruction of ovarian follicles with a subsequently decreased amount of theca and/or granulosa cells, destruction of ovarian stromal tissue with the subsequent development of transient but purulent and acute inflammatory reactions to initiate the immune response, and the continuing leakage or drainage of “toxic” follicular fluid in these immature and growth-ceased pre-antral follicles. All these factors contribute to decreasing local and systemic androgen levels, the following apoptosis process with these pre-antral follicles to atresia; the re-starting of normal follicular recruitment, development, and maturation, and finally, the normalization of the “hypothalamus–pituitary–ovary” axis and subsequent spontaneous ovulation. The detailed local and systematic changes in PCOS women after LOD are comprehensively reviewed in the current article.

Ovarian Drilling in PCOS: Is it Really Useful?

Polycystic ovary syndrome (PCOS) is a frequent disorder, affecting approximately 5-10% of infertile women. It can represent more than 80% of cases of infertility due to anovulation. The main goal of treatment is the induction of mono-ovulatory cycles. A pragmatic management of infertility in PCOS will allow most patients to conceive. Weight loss and clomiphene citrate (CC) are the first-line components of patients treatment before gonadotrophins are used. However, during gonadotrophin administration, there is a high risk of ovarian hyper-stimulation and multiple pregnancies. So, surgery with laparoscopic ovarian drilling is often used before gonadotrophins in order to obtain normal ovulatory cycles.

Expression and clinical significance of the HIF-1a/ET-2 signaling pathway during the development and treatment of polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a major health problem in reproductive-aged women worldwide, but the precise pathogenesis of PCOS remains unclear. Our previous study revealed that hypoxia-inducible factor (HIF)-1a mediated endothelin (ET)-2 signaling plays an important role in ovulation in rats. Therefore, the present study used a PCOS rat model to test the hypotheses that HIF-1a signaling is expressed and inhibited in ovaries during PCOS formation and that the HIF-1a/ET-2 signaling pathway is a target of dimethyldiguanide (DMBG) in the clinical treatment of PCOS. First, the development of a PCOS model and the effect of DMBG treatment were examined through ovarian histology and serum hormone levels, which were consistent with previous reports. Second, HIF-1a and ET-2 expression were detected by immunohistochemistry and western blot. The results showed decreased HIF-1a/ET-2 expression in the ovaries of PCOS rats, whereas DMBG treatment reversed the protein decreases and improved the PCOS symptoms. Third, to understand the molecular mechanism, HIF-1a/ET-2 mRNA expression was also examined. Interestingly, HIF-1a mRNA increased in the ovaries of PCOS rats, while ET-2 mRNA decreased, indicating that HIF-1a protein degradation may be involved in POCS development and treatment. Finally, HIF prolyl hydroxylase (PHD) activity was examined to further clarify the contribution of HIF-1a signaling to the development and treatment of PCOS. The results suggested that the inhibition of HIF-1a/ET-2 signaling may be caused by increased PHD activity in PCOS. DMBG-treated PCOS may further activate HIF-1a signaling at least partly through inhibiting PHD activity. Taken together, these results indicate that HIF-1a signaling is inhibited in a PCOS rat model through increasing PHD activity. DMBG treatment improved PCOS by rescuing this pathway, suggesting that HIF-1a signaling plays an important role in the development and treatment of PCOS. This HIF-1a-mediated ET-2 signaling pathway may be an important mechanism regulating PCOS formation and treatment in mammalian ovaries in vivo and should be a new clinical target for PCOS prevention and treatment in the future.