Elevated hypothalamic aromatization at the onset of precocious puberty in transgenic female mice hypersecreting human chorionic gonadotropin: effect of androgens

Elevated chorionic gonadotropic hormone in transgenic mice induces parthenogenetic activation and ovarian teratomas

Both male and female reproductive functions are impacted by altered gonadotrophin secretion and action, which may also influence the development of endocrine tumours. To ascertain if chronic hypersecretion of human chorionic gonadotropin (hCG) contributes to the development of gonadal tumours, double transgenic (TG) mice that overexpress hCGα- and β-subunits were analysed. By the age of two months, ovarian tumours with characteristics of teratomas developed with 100% penetrance. Teratomas were also seen in wild-type ovaries orthotopically transplanted into TG mice, demonstrating an endocrine/paracrine mechanism for the hCG-induced ovarian tumorigenesis. Both in vitro and in vivo experiments showed oocyte parthenogenetic activation in TG females. In addition, ovaries showed reduced ovulatory gene expression, inhibited ERK1/2 phosphorylation, and impaired cumulus cell expansion. Hence, persistently high endocrine hCG activity causes parthenogenetic activation and development of ovarian teratomas, along with altered follicle development and impaired ERK1/2 signalling, offering a novel mechanism associated with the molecular pathogenesis of ovarian teratomas.

Medical symptoms and conditions in autistic women

The sex bias in autism diagnosis suggests the involvement of sex-specific endocrine mechanisms during prenatal development, but these hormones affect health throughout life. Therefore, the current study examined the association of autism and autistic traits with conditions and symptoms related to the sex-steroid system in adult women. In total, 1230 women (361 autistic), aged 15–77 years, reported on autistic traits and medical history. Medical diagnoses and symptoms were grouped by unsupervised factor analysis, and associations with autism diagnosis and autistic traits were explored. Higher rates of reproductive system diagnoses (odds ratio = 1.035, p = 0.024), prediabetes symptoms (odds ratio = 1.319, p = 0.001), irregular puberty onset (odds ratio = 1.458, p = 0.009), and menstrual length (odds ratio = 1.368, p = 0.034) and lower rates of metabolic and vascular conditions (odds ratio = 0.654, p = 0.013) were associated with diagnosis. Reproductive system diagnoses (β = 0.114, p = 0.000), prediabetes symptoms (β = 0.188, p = 0.000), menstrual length (β = 0.071, p = 0.014), irregular puberty onset (β = 0.149, p = 0.000), excessive menstruation symptoms (β = 0.097, p = 0.003), and hyperandrogenism symptoms (β = 0.062, p = 0.040) were also associated with autistic traits. Many of the conditions and symptoms found to be associated with autism or autistic traits are also related to conditions of steroid hormones and, specifically, the sex-steroid system. The study suggests an important role for steroids in autistic women, beyond prenatal development. Clinical implications are discussed.

Mouse Models for the Study of Synthesis, Secretion, and Action of Pituitary Gonadotropins

Gonadotropins play fundamental roles in reproduction. More than 30years ago, Cga transgenic mice were generated, and more than 20years ago, the phenotypes of Cga null mice were reported. Since then, numerous mouse strains have been generated and characterized to address several questions in reproductive biology involving gonadotropin synthesis, secretion, and action. More recently, extragonadal expression, and in some cases, functions of gonadotropins in nongonadal tissues have been identified. Several genomic and proteomic approaches including novel mouse genome editing tools are available now. It is anticipated that these and other emerging technologies will be useful to build an integrated network of gonadotropin signaling pathways in various tissues. Undoubtedly, research on gonadotropins will continue to provide new knowledge and allow us transcend from benchside to the bedside.

The correlation of aromatase activity and obesity in women with or without polycystic ovary syndrome

Background

This study aimed to investigate the effect of polycystic ovary syndrome (PCOS) on the association of aromatase activity assessed by estradiol-to-testosterone ratio (E₂/T) with body mass index (BMI) in women.

Methods

This was a cohort study in five centers for reproductive medicine in China. Data were collected from July 2012 to December 2013. PCOS patients (n = 785) and non PCOS, healthy, age-matched controls (n = 297) were included. Plasma sex hormones including estradiol (E₂), testosterone (T), follicle stimulating hormone (FSH), and luteinizing hormone (LH) were measured by ELISA, together with BMI and E₂/T being calculated, on the third day of the menstrual cycle. Aromatase activity in PCOS patients with different BMI, T and E₂ levels were compared.

Results

E₂/T was significantly lower (P < 0.05) while BMI was significantly increased (P < 0.05) in PCOS than non-PCOS. No significant difference was observed in E₂/T among different BMI subgroups of either PCOS or control. Ovarian aromatase activity was decreased in PCOS patients which was independent of BMI. Hyperestrogen promoted ovarian aromatase activity, while hyperandrogen inhibited such activity, both in a dose-dependent, biphasic manner.

Conclusions

Ovarian aromatase activity was lower in PCOS, which was independent of BMI. New therapeutic strategies can be developed by targeting aromatase activity for treating PCOS women, especially those with obesity.