| Polycystic ovary syndrome（PCOS）is a syndrome that seriously affects the reproductive health of women.The pathogenesis of PCOS is unclear.In view of factors such as ethics and test costs,the use of PCOS-like mice induced by dehydroepiandrosterone（DHEA）has become an important animal model for such study.This study used DHEA（6 mg/100 g）to subcutaneously inject KM mice for 20 days to induce the production of PCOS;Then,mouse sexual cycle was identified by crystal violet staining;the ovarian development status was determined with HE staining;and the changes of serum estradiol concentrations during the modeling process were evaluated using ELISA methods.Finally,the serum E2 level of the mice in the control group and the DHEA group on the 10th day of model establishment were respectively set to be low（physiological concentration）and high（pathological concentration）in vitro addition concentrations,and a Western blot protein expression technology is utilized to investigate the expression of Estrogen receptor alpha/beta（ERα/β）in granulosa cells cultured in vitro.The results showed that continuous subcutaneous injection of DHEA in KM mice from 3 weeks of age resulted in a certain degree of the sexual cycle arrest,follicle vesicularization,and pathological features of obesity and hyperandrogenism.It suggested that DHEA could successfully induce KM mice to have PCOS model characteristics.During the modeling process,it was found that the production process of PCOS was accompanied by a phased change in serum E2 levels that first increased and then decreased.In order to explore the possible pathological significance of the transient increase of E2 in the process of modeling,we first established an in vitro culture system using granulosa cells from 3-week-old mice.The results showed that the ovarian cells released by mechanical method were follicle-stimulating hormone receptor-positive granulosa cells,and the F1 generation cells showed a typical"S"growth curve,indicating that the granulosa cells cultured in vitro grew well and could be used for subsequent experiments.The F1 granulosa cells were subsequently induced in vitro with the above two different concentrations of E2.The results showed that both low concentration E2（7ng/m L）and high concentration E2（20 ng/m L）could promote the proliferation of granulosa cells.In terms of estradiol receptor expression,low and high concentrations of E2 had no significant effect on the expression levels of ERαand ERβ,but high concentrations of E2 significantly increased the ratio between ERαand ERβ.This imbalance of ratios was also manifested in granulosa cells in PCOS mice.It is suggested that the increased ratio between ERαand ERβinduced by high concentration of E2 may be one of the factors leading to the occurrence of PCOS.In summary,in present study,a DHEA-induced PCOS model was established in Kunming white mice,in which the serum E2 level increased first and then decreased;The ratio of ERα/ERβin granulosa cells could be increased by adding the corresponding pathological concentration of E2 in vitro,which was similar to the granulosa cells of PCOS mice in vivo,that is,high E2 may participate in the induction of PCOS-like granulosa-like cells and the occurrence of diseases by increasing the ratio of ERα/ERβ. |
