A Preliminary Study Of Estrogen On Endometrial Decidualization And Spontaneous Pregnancy Impacts

As the important steroid hormones in the female, estrogen and progesterone play an important role in the maintenance and regulation of normal female reproductive and physiological events. Periodic changes of hormone levels exist in women who exhibit regular physiological menstrual cycle. During pregnancy, the appropriate levels of estrogen and progesterone are the most basic conditions to maintain pregnancy, both hormone coordinate a series of events relative to embryo implantation.Compared with progesterone, the regulation of estrogen was more precise. In this study, we mainly focus on three aspects, to explore the physiological and pathological events under the control of estrogen and progesterone.1. Spontaneous decidualizationWhy do human menstruate while most mammals do not? This is a long-debated question. The root of this question is spontaneous decidualization (SD). SD is a physiological phenomenon unique to menstrual animals. The phenomenon occurs only in higher primates and few other placental animals. In this part of the study, we used estrogen in the absence of uterine-stimulation induced spontaneous decidualization in rats, the probability of SD up to40%, indicating the molecular basis of SD also existed in the non-menstrual animals. Compared with decidualization induced by other uterine stimulation, we found that the efficiency of decidualization beginning was different under different inducing factors. By analyzing the early changes of molecular in the uterus under various treatment factors, we found that Stat3signaling pathway plays an important role in the boot process of decidua. Under the situation of induce by estrogen alone, whether SD initiated dependent on whether Stat3signaling pathway activated or not. The experimental results showed that estrogen induce the expression of LIF and Stat3further activated by LIF, but the activation level of Stat3vary in different rat. The difference may affect the probability of the occurrence of SD.2. Effect of estrogen treatment in early pregnancy on pregnancy outcomeIn the present study, we found that estrogen-related treatment in early pregnancy seriously affected the development process of fetus and placenta in rat. Fetal development suppression, weight loss and metrial gland hypotrophy were presented out after treated with low dose estrogen in early pregnancy. However, letrozole treatment has led to excessive fetal placental hypertrophy; placental structure changed significantly, even in late pregnancy dystocia phenomenon appeared. All of these shows that maternal estrogen levels during early pregnancy may affect the entire duration of pregnancy. The more detail is that estrogen-related treatment in early pregnancy promotes angiogenesis, endovascular trophoblast invasion and spiral artery remodeling. This process accompanied with uNK cell recruitment to the perivascular and the expression of HIF and MMP-2.3. Mechanism of menstrua under the control of hormonesMenstruation is a physiological phenomenon of endometrium periodic shedding under the fine regulation of estrogen and progesterone. We found that ROS play a critical role in endometrial breakdown in the mouse menstrual-like model. NAC (an inhibitor of ROS) completely inhibited endometrial breakdown. The data showed that ROS are important for endometrial breakdown, and exert their effects via NF-κB-COX-2signaling according to the in vivo, in virto and molecular analysis results.