Dragana Tomic

Smad 3 May Regulate Follicular Growth in the Mouse Ovary

Abstract Although Smad 3 is known to serve as a signaling intermediate for the transforming growth factor beta (TGFβ) family in nonreproductive tissues, its role in the ovary is unknown. Thus, we used a recently generated Smad 3-deficient (Smad 3−/−) mouse model to test the hypothesis that Smad 3 alters female fertility and regulates the growth of ovarian follicles from the primordial stage to the antral stage. In addition, we tested whether Smad 3 affects the levels of proteins that control apoptosis, survival, and proliferation in the ovarian follicle. To test this hypothesis, breeding studies were conducted using Smad 3−/− and wild-type mice. In addition, ovaries were collected from Smad 3−/− and wild-type mice on Postnatal Days 2–90. One ovary from each animal was used to estimate the total number of primordial, primary, and antral follicles. The other ovary was used for immunohistochemical analysis of selected members of the B-cell lymphoma/leukemia-2 family of protooncogenes (Bax, Bcl-2, Bcl-x), proliferating cell nuclear antigen (PCNA), and cyclin-dependent kinase 2 (Cdk-2). The results indicate that Smad 3−/− mice have reduced fertility compared with wild type mice. The results also indicate that Smad 3 may not affect the size of the primordial follicle pool at birth, but it may regulate growth of primordial follicles to the antral stage. Further, the results indicate that Smad 3 may regulate the expression of Bax and Bcl-2, but not Bcl-x, Cdk-2, and PCNA. Collectively, these data suggest that Smad 3 may play an important role in the regulation of ovarian follicle growth and female fertility.

The aryl hydrocarbon receptor affects mouse ovarian follicle growth via mechanisms involving estradiol regulation and responsiveness.

Abstract The aryl hydrocarbon receptor (AHR) is a known transcription factor. Although studies indicate that Ahr-deficient (AhRKO) mice have defects in female reproduction, only a few studies have examined the role of AHR in the ovary. Previous studies have suggested, without directly testing, that AhRKO mice have slower follicular growth than wild-type (WT) mice. Therefore, the first objective of the present study was to examine whether AhRKO follicles grow slower than WT follicles and if so, to determine whether the mechanism by which Ahr affects follicular growth is through effects on antrum size, granulosa cell proliferation, and regulators of cell cycle progression. Since estradiol (E2) is critical for the normal growth of ovarian follicles, the second objective of the present study was to determine the role of Ahr in regulating E2 production and responsiveness. The third objective of the present study was to determine whether E2 replacement restores follicular growth of AhRKO follicles to WT levels in vitro. We found that AhRKO follicles grew slower than WT follicles in vitro. While AhRKO and WT follicles had similar antrum sizes, AhRKO follicles showed decreased granulosa cell proliferation and reduced mRNA and protein levels of cell cycle regulators, as compared to WT follicles. Furthermore, the AhRKO mice had lower serum and follicle-produced E2 levels and showed decreased Esr1 and Esr2 mRNA levels compared to WT mice. Finally, E2 treatment of AhRKO follicles restored follicular growth to WT levels in vitro. Collectively, these findings suggest that the AHR affects follicular growth via mechanisms that involve E2 regulation and responsiveness.

Correlates of sexual functioning among mid-life women

Objective Studies have reported a decline in sexual functioning among women undergoing the menopausal transition. Few studies, however, have examined the associations between hormones and sexual dysfunction during this time period. Therefore, the purpose of this study was to examine the associations between participant characteristics and endogenous hormones with sexual functioning in mid-life women. Methods Data were analyzed from a community-based sample of 441 women aged 45–54 years who stated that they were sexually active at the time of the study. Each participant completed a survey that included questions pertaining to sexual functioning and provided a blood sample that was used to measure estrogen and androgen concentrations. Results Among women who reported being sexually active, poorer self-reported health and the experiencing of depressive symptoms were significantly associated with not being satisfied with sexual relations after adjustment for other covariates. None of the hormones examined were significantly associated with overall sexual satisfaction. However, statistically significant associations between both total testosterone levels and the free testosterone index with satisfaction with the frequency of sexual relations were observed. Conclusions Our findings indicate that the experiencing of depressive symptoms and the reporting of poor overall health are important correlates of sexual dysfunction. Further, our results suggest that higher total and free testosterone levels are significantly associated with a desire for increased frequency of sexual relations among mid-life women.