Investigation Of The Mechanism Of Endocannabinoid System On Endometrial Decidualization In Patients With PCOS

Objective:To establish the method of primary culture and induce decidualization of PCOS patients' endometrial stromal cells in vitro,to investigate the relationship of endocannabinoid system and endometrial markers in endometrial decidualization in patients with PCOS,and to further explore the mechanism of endometrial stromal abnormalities in decidualization in the PCOS patients,aiming to provide the theoretical basis about improving PCOS endometrial receptivity,increasing the pregnancy rate of PCOS patients and reducing pregnancy complications.Methods:We selected 10 cases of PCOS patients as the PCOS group and10 patients with normal menstruation and normal basal hormone as the control group from January to June in 2017,visited in Reproductive Medicine Department of the second hospital of Hebei Medical University.Proliferative endometrium of all the subjects were taken 3 to 7 days after menstruation.Primary culture of stromal cells was performed by separating HEEC and HESC,all the cells were treated with MPA+8-Br-cAMP to induce decidualization,followed by intervention with endocannabinoid receptor 1(CBR-1)antagonist or CBR-1 agonist.We take the 0h,24 h,48h,72 h as four time point to observed decidualization morphological changes and specific decidual factor(LIF and ItgB3)expression of the two groups.Results:1.Under the microscopy,the non-decidualized endometrial stromal cells are polygonal and the decidualized are spindle-like.2.Endometrial decidualization is incomplete within PCOS group.3.The level of CB1 increased in PCOS decidua group(P<0.05),while the level of LIF and ItgB3 increased in PCOS decidua group(P<0.05),suggested that CB1 mRNA level may inhibit LIF and ItgB3 mRNA levelexpression.4.The level of CB1 in PCOS decidualized group was lower than that in PCOS group(P<0.05).5.In the process of endometrial decidualization in vitro,CB1 antagonists promoted the expression of ItgB3,and CB1 agonists inhibited the expression of LIF and ItgB3.Conclusions:Our results revealed that endometrial decidualization in the PCOS patients is incomplete,which may be one of the reasons for its low pregnancy.We demonstrated that CB1 gene expression levels related to the degree of decidualization.High CB1 levels in decidual cells inhibited the expression of LIF and ItgB3 genes.It suggested that it may be one of the mechanisms of ECS abnormalities affected the decidualization of PCOS.