Evaluation of follicular synchronization caused by estrogen administration and its reproductive outcome

Steroid Hormone Profiling in Hyperandrogenism and Non-hyperandrogenism Women with Polycystic Ovary Syndrome

The purpose of this study is to explore the differences in the steroid metabolic network between hyperandrogenic and non-hyperandrogenic women with polycystic ovary syndrome (PCOS). A sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) was employed for the quantification of 36 kinds of serum steroids in 80 PCOS women during their follicular phase. Compared with those in non-hyperandrogenemia PCOS women (NA-PCOS), the levels of 17-hydroprogesterone (P = 0.009), androstenedione (P < 0.001), total testosterone (P < 0.001), dihydrotestosterone (P = 0.025), estrone (P = 0.007), and estradiol (P < 0.001) were increased in hyperandrogenemia PCOS (HA-PCOS) women. It was suggested that HA-PCOS may have increased activity of P450c17 (17-hydropregnenolone/pregnenolone, P = 0.008), 3βHSD2 (androstenedione/dehydroepiandrosterone, P = 0.004), and 17βHSD3 (testosterone/dehydroepiandrosterone, P = 0.01) and decreased activity of 5α reductase (dihydrotestosterone/testosterone, P = 0.008). Moreover, the ratio of luteinizing hormone (LH) to follicle stimulating hormone (FSH) was found to be related to these increased steroids and enzyme activities. In conclusion, the HA-PCOS and the NA-PCOS women showed different steroid profiles, and the different enzyme activities in steroidogenic pathway may be the main reason for the difference.

Chronic Estrus Disrupts Uterine Gland Development and Homeostasis

Female mice homozygous for an engineered Gnrhr E90K mutation have reduced gonadotropin-releasing hormone signaling, leading to infertility. Their ovaries have numerous antral follicles but no corpora lutea, indicating a block to ovulation. These mutants have high levels of circulating estradiol and low progesterone, indicating a state of persistent estrus. This mouse model provided a unique opportunity to examine the lack of cyclic levels of ovarian hormones on uterine gland biology. Although uterine gland development appeared similar to controls during prepubertal development, it was compromised during adolescence in the mutants. By age 20 weeks, uterine gland development was comparable to controls, but pathologies, including cribriform glandular structures, were observed. Induction of ovulations by periodic human chorionic gonadotropin treatment did not rescue postpubertal uterine gland development. Interestingly, progesterone receptor knockout mice, which lack progesterone signaling, also have defects in postpubertal uterine gland development. However, progesterone treatment did not rescue postpubertal uterine gland development. These studies indicate that chronically elevated levels of estradiol with low progesterone and therefore an absence of cyclic ovarian hormone secretion disrupts postpubertal uterine gland development and homeostasis.

LncPrep + 96kb 2.2 kb Inhibits Estradiol Secretion From Granulosa Cells by Inducing EDF1 Translocation

LncPrep + 96kb is a novel long non-coding RNA expressed in murine granulosa cells with two transcripts that are 2.2 and 2.8 kb in length. However, the potential roles of lncPrep + 96kb in granulosa cells remain poorly understood. In this study, we investigated the effect of the lncPrep + 96kb 2.2 kb transcript on granulosa cells through the overexpression and knockdown of lncPrep + 96kb 2.2 kb. We found that lncPrep + 96kb 2.2 kb inhibited aromatase expression and estradiol production. Endothelial differentiation-related factor 1 (EDF1) is an evolutionarily conserved transcriptional coactivator. We found that EDF1 knockdown inhibited aromatase expression and estradiol production. The RNA immunoprecipitation results also showed that lncPrep + 96kb 2.2 kb can bind to EDF1 and that overexpression of lncPrep + 96kb 2.2 kb induced the translocation of EDF1 from the nucleus to the cytoplasm. The CatRAPID signature revealed that the 1,979–2,077 and 603–690 nucleotide positions in lncPrep + 96kb 2.2 kb were potential binding sites for EDF1. We found that mutating the 1,979–2,077 site rescued the effects of lncPrep + 96kb 2.2 kb on aromatase expression and estradiol production. In conclusion, we are the first to report that specific expression of lncPrep + 96kb 2.2 kb in granulosa cells inhibits the production of estradiol by influencing the localization of EDF1 in granulosa cells. The 1,979–2,077 site of lncPrep + 96kb 2.2 kb contributes to the ability to bind to EDF1.

Combined treatment with cysteamine and leukemia inhibitory factor promotes guinea pig oocyte meiosis in vitro

The guinea pig is an excellent but underused animal model due to its reproductive biology, which poses difficulties in inducing superovulation, embryo manipulation in vitro, and embryo transfer. We examined the effects of cysteamine (Cys), leukemia inhibitory factor (LIF), and Y27632 on guinea pig oocyte in vitro maturation (IVM). Cumulus-oocyte complexes were collected from antral follicles and classified into three different types before IVM. Among type I oocytes, maturation rates to metaphase II (MII) were similar in basal maturation medium and medium supplemented with Cys or LIF (39.5-40.9%), but combined Cys and LIF treatment increased the MII rate to 61.8%. Supplementation with Y27632 alone or in combination with Cys and LIF dramatically reduced the MII rate (27.7-29.7%). Similar trends were observed for type II oocytes, although their overall MII rate was lower than that of type I oocytes. The MII rate was higher among oocytes collected from 2-month-old guinea pigs compared with those from 4-month-old guinea pigs (56.5 vs. 44.8%). The optimal IVM duration was 24 h (52.5%), as 36 or 48 h of IVM reduced the MII rate (32.8-42.5%). Furthermore, Y27632 reduced the presence of microfilaments in oocytes. These findings indicate that combined supplementation of maturation medium with Cys and LIF, but not Y27632, improves the maturation efficiency of guinea pig oocytes. This study provides an important scientific basis for further efforts toward guinea pig in vitro fertilization, cloning, and gene editing by establishing an animal model for human reproduction and related diseases.

How to choose the suitable animal model of polycystic ovary syndrome?

Polycystic ovary syndrome (PCOS) is a gynecological metabolic and endocrine disorder with uncertain etiology. To understand the etiology of PCOS or the evaluation of various therapeutic agents, different animal models have been introduced. Considering this fact that is difficult to develop an animal model that mimics all aspects of this syndrome, but, similarity of biological, anatomical, and/or biochemical features of animal model to the human PCOS phenotypes can increase its application. This review paper evaluates the recently researched animal models and introduced the best models for different research purposes in PCOS studies. During January 2013 to January 2017, 162 studies were identified which applied various kinds of animal models of PCOS including rodent, primate, ruminant and fish. Between these models, prenatal and pre-pubertal androgen rat models and then prenatal androgen mouse model have been studied in detail than others. The comparison of main features of these models with women PCOS demonstrates higher similarity of these three models to human conditions. Thereafter, letrozole models can be recommended for the investigation of various aspects of PCOS. Interestingly, similarity of PCOS features of post-pubertal insulin and human chorionic gonadotropin rat models with women PCOS were considerable which can make it as a good choice for future investigations.