Contribution And Regulatory Mechanism Of HIF-1 Signaling In Polycystic Ovary Syndrome

Polycystic ovary syndrome(PCOS)is a heterogeneous disease that affects the reproductive health and the life quality of the women during the childbearing age.At present,the specific pathophysiology of PCOS has not been well demonstrated.But insulin resistance,chronic low inflammation,and oxidative stress may play a vital role during the development and progression of PCOS.The present project used drugs to establish PCOS rat model to further investigate the related molecular menchism through a variety of biotechnology research methods,in order to elucidate the contribution and its regulatory menchism of HIF-1 signaling pathway during the development of PCOS pathophysiology and the treatment of PCOS with dimethyldiguanide(DMBG),.The detailed findings of the present project as following:1.HIF-1 signaling pathway plays an important role during mammalian ovulation,but the contribution of HIF-1 signaling to PCOS ovarian dysfunction was not reported.Therefore,this study used the drugs to successfully induce PCOS rat model which was used to examine the expression of related functional proteins.The results indicate HIF-1α/ET-2 signaling may play an important role during the development of PCOS.2.For further investigating the molecular mechanisms of the PCOS development,the present experiment used DMBG to treat PCOS rats and examined the expression and localization of HIF-1α and ET-2.These results indicated that HIF-la/ET-2 sigaling pathway really participated in the development and treatment of PCOS.3.Akt is a main upstream protein of HIF-1,which exerts its physiological effects through two phosphorylation sites of Akt.For further clarifying the regulatory role of HIF-la/ET-2 during the development of PCOS,the present experiment further analyzed the expression patterns of Akt/pAkt in the PCOS rat ovaries.These results indicated that Akt sigaling may participate in the development and treatment of PCOS via HIF-la/ET-2 pathway.4.Selective insulin resistance plays an important role in the ovarian dysfunction of PCOS,which mainly shows that insulin-mediated PI-3K/AKT pathway defects.Akt plays an important role in insulin-mediated PI-3K signaling,and the above studies have found the abnormal expressions of Akt/pAkt in the ovaries of PCOS rats,but whether other members of PI-3K/Akt signaling pathway are abnormal needs further investigation.These data suggested the defects of insulin-mediated PI-3K/Akt signaling pathway may be one of major factors induced PCOS.5.Insulin resistance and the defects of insulin signaling pathway cause a variety of pathological features,such as chronic low grade inflammation and oxidative stress.The present experiment confimed the existence of inflammation,and NLRP3 inflammasome were activated during the occurrence of ovarian inflammation in PCOS rats.Inadditionally,oxidative stress markers activities and LPO concentrations were obviously increased in the ovaries of PCOS rats.DMBG improved the chronic low grade inflammatory state in PCOS ovaries by inhibiting the activation of NLRP3 inflammation and then reducing the level of LPO.These results demonstrated that NLRP3 inflammasome not only plays a role in the development and treatment of PCOS,but also is a new target of PCOS treatment in the near future.6.To confirm the findings of animal experiments,the present experiments also examined the changes of Akt/HIF-1 signaling pathway through in vitro culture of ovarian granulosa cells.The results indicate Akt/HIF-1 signaling participated in the regulation of ovarian functions.In additional,given the insulin resistance features of granulosa cells treated with PI-3K inhibitors dramatically inhibited the expressions of HIF-la/ET-2 induced by insulin.The findings are partly consistent with our previous findings of animal experiments.The findings of the present project demonstrated the defects of PI-3K/AKT/HIF-1 signaling and the neuroendocrine dysfunction of hypothalamic-pituitary-ovarian axis are the important mechanisms of ovarian dysfunction in PCOS rats.Additionally,the activation of NLRP3 inflammasome induced by oxidative stress during the occurrence of ovarian chronic low grade inflammation may also play an important regulatory role during the development and treatment of PCOS,which may be a new target of PCOS treatment in the near future.All of these findings will provide an improtant theoretical guidance and practical basis for the prevention and treatment of human PCOS in clinical.