Maternal Testosterone Excess Contributes to Reproductive System Dysfunction of Female Offspring Mice

Somatic cell fate maintenance in mouse fetal testes via autocrine/paracrine action of AMH and activin B

Fate determination and maintenance of fetal testes in most mammals occur cell autonomously as a result of the action of key transcription factors in Sertoli cells. However, the cases of freemartin, where an XX twin develops testis structures under the influence of an XY twin, imply that hormonal factor(s) from the XY embryo contribute to sex reversal of the XX twin. Here we show that in mouse XY embryos, Sertoli cell-derived anti-Mullerian hormone (AMH) and activin B together maintain Sertoli cell identity. Sertoli cells in the gonadal poles of XY embryos lacking both AMH and activin B transdifferentiate into their female counterpart granulosa cells, leading to ovotestis formation. The ovotestes remain to adulthood and produce both sperm and oocytes, although there are few of the former and the latter fail to mature. Finally, the ability of XY mice to masculinize ovaries is lost in the absence of these two factors. These results provide insight into fate maintenance of fetal testes through the action of putative freemartin factors.

Intrauterine endogenous high glucocorticoids program ovarian dysfunction in female offspring secondary to prenatal caffeine exposure

Ovarian dysfunction has an intrauterine origin, and prenatal caffeine exposure (PCE) could lead to abnormal follicle counts in offspring after birth. However, the effect of PCE on offspring ovarian function and its mechanism of intrauterine programming have not been reported thus far. In this study, pregnant Wistar rats were intragastrically administered caffeine (30 and 120 mg/kg·d) at gestational days 9-20 (GD9-20). Certain tests were performed on the blood, ovaries and hypothalamus of female offspring at different time points. PCE female offspring had ovarian dysfunction in adulthood compared with the control. Further results showed that in utero ovarian morphological development and estradiol synthesis were inhibited but rapidly increased during puberty in the PCE group. The histone 3 lysine 27 acetylation (H3K27ac) level of the insulin-like growth factor 1 (IGF1) promoter region and its expression were decreased in the ovary, which was due to exposure to high levels of fetal blood corticosterone, and the H3K27ac level of IGF1 and its expression shifted to increase after birth with a decrease in serum corticosterone levels. Chronic stress led to increased serum corticosterone levels in adult offspring, whereas ovarian morphological development, the H3K27ac level of IGF1 and its expression, and estradiol synthesis were significantly inhibited. Moreover, the activity of the hypothalamic-pituitary-ovarian (HPO) axis was increased in the early postnatal period of PCE offspring, and chronic stress reversed these changes. In the KGN cell line, it was found that cortisol could promote the translocation of the glucocorticoid receptor (GR) into the nucleus and upregulate histone deacetylase 10 (HDAC10) to inhibit the H3K27ac level of IGF1 and its expression and estradiol synthesis. In summary, PCE is associated with ovarian dysfunction in female adult offspring, and the potential mechanism is related to intrauterine high glucocorticoid exposure by activating the GR and recruiting HDAC10 to affect ovarian glucocorticoid-IGF1 axis programming and to inhibit estradiol synthesis.

Transgenerational Inheritance of Reproductive and Metabolic Phenotypes in PCOS Rats

Androgen exposure of female fetuses could be an important factor in the development of polycystic ovary syndrome (PCOS) in subsequent generations. The present study aimed to investigate the transgenerational effects of PCOS on the growth, reproduction, and metabolism of the first- and second-generation offspring in rats. Female F0 rats received excessive dehydroepiandrosterone (DHEA) exposure to establish PCOS or the same amount of vehicle as controls. These F0 females were crossed with normal males to obtain control (C) and DHEA (D) F1 offspring, whereas F2 offspring were obtained by inter-crossing between F1 rats for 4 groups: (1) C♂-C♀; (2) D♂-C♀; (3) C♂-D♀ and (4) D♂-D♀. Compared with control groups, F1 and F2 offspring with ancestral DHEA exposure showed higher body weight with increasing age. In addition, female F1 and F2 offspring with ancestral DHEA exposure exhibited PCOS-like reproductive and metabolic phenotypes, including disrupted estrous cycles and polycystic ovaries, as well as increased serum levels of testosterone, impaired glucose tolerance and widespread metabolic abnormalities. Male offspring with ancestral DHEA exposure exhibited lower quality of sperms. These findings confirm the negative effects of excessive androgen exposure of female fetuses on subsequent generations.