Diethylstilbestrol regulates mouse gubernaculum testis cell proliferation via PLC-Ca2+ -CREB pathway.

Recent evidence suggested a positive correlation between environmental estrogens (EEs) and high incidence of abnormalities in male urogenital system, but the mechanism remains unclear. Diethylstilbestrol (DES) is a nonsteroidal synthetic estrogen that disrupts the morphology and proliferation of gubernaculum testis cells, but the underlying mechanism is unclear. In this study, mouse gubernaculum testis cells were pretreated with phospholipase C (PLC) inhibitor U-73122 and then treated with DES. The results demonstrated that U-73122 impaired DES-evoked intracellular Ca2+ mobilization in gubernaculum testis cells and inhibited DES-induced proliferation of gubernaculum testis cells. Mechanistically, we found that U-73122 inhibited DES-induced activation of cAMP-response element binding protein (CREB) in gubernaculum testis cells. In conclusion, these data suggest that the effects of DES on mouse gubernaculum testis cells are mediated by PLC-Ca2+ -CREB pathway. SIGNIFICANCE OF THE STUDY: Environmental estrogens remain a serious threat to male reproductive health, and it is important to understand the mechanism by which EEs affect the male productive system. Here we explore potential mechanisms how the proliferation and contractility of gubernaculum testis cells are regulated by diethylstilbestrol. Our findings provide the first evidence that PLC-Ca2+ -CREB signalling pathway mediates the nongenomic effects of diethylstilbestrol on gubernaculum testis cells. These findings provide new insight into the role of diethylstilbestrol in the aetiology of male reproductive dysfunction and will help develop better approaches for the prevention and therapy of male reproductive malformation.

[Impacts of DES on the expressions of related genes in the gubernaculums testis of newborn mice].

OBJECTIVE: To investigate the influence of diethylstilbestrol (DES) on the mRNA expressions of the androgen receptor (AR), estrogen receptor α (ERα), proliferating cell nuclear antigen (PCNA), and actin alpha 1 (ACTα1) in the gubernaculums testis of newborn mice and explore their action mechanisms. METHODS: A total of 140 male Kunming mice were randomly divided into a blank control, a dimethyl sulfoxide (DMSO) control, and 5 experimental groups to be treated subcutaneously with normal saline, DMSO, and DES at 0.02, 0.1, 0.5, 10 and 50 µg per kg of the body weight per day, respectively, at gestation days 9－17. On the first day after birth, the animals were sacrificed and the gubernaculums testis collected for detection of the mRNA expressions of AR, ERα, PCNA and ACTα1 by RT-PCR. RESULTS: Compared with the DMSO control, the experimental groups, particularly the DES 10 and 50 µg groups, showed significant increases in the mRNA expression of ERα (RE2 = 0.825, P <0.05), but remarkable decreases in those of AR, PCNA and ACTα1 (RA2 = 0.713, RP2 = 0.946, RT2 = 0.960, P <0.01), all in a dose-dependent manner. CONCLUSIONS: The AR, ERα, PCNA, and ACTα1 mRNA are expressed in the gubernaculum testis of normal newborn mice, and their expression levels may be influenced by intervention with different concentrations of DES during the gestation. Exogenous estrogens may affect the proliferation and contraction of gubernaculum testis cells and consequently the normal development of the testis or even the whole male reproductive system by influencing the metabolism of ER and/or AR.