The impact of flutamide on prostaglandin F2α synthase and prostaglandin F2α receptor expression, and prostaglandin F2α concentration in the porcine corpus luteum of pregnancy

Role of 14-3-3β protein on ovarian folliculogenesis, steroidogenesis and its correlation in the pathogenesis of PCOS in mice

This study was designed to assess for the first time the circulating and ovarian level of 14-3-3β protein in the PCOS mice and the possible correlation between 14-3-3β protein with PCOS related increase in testosterone (HA), insulin levels (HI) and reduced insulin sensitivity in the ovary. PCOS was induced in mice using treatment of letrozole (by oral gavage) for 21 days. Immunohistochemical study showed increased expression of 14-3-3β protein in PCOS ovary compared to the control ovary. The circulating testosterone and insulin levels, together with circulating and ovarian levels of 14-3-3β protein also showed significant increase in PCOS mice compared to the control mice. An increase in 14-3-3β protein was observed positively correlated with circulating testosterone and insulin levels but showed a negative correlation with ovarian expression of insulin receptor protein in PCOS mice. The treatment of 14-3-3β protein in vitro to the normal ovary showed a significant increase in testosterone synthesis but a significant decline in insulin receptor protein expression compared to the vehicle-treated ovary of adult mice. The present study showed the direct role of 14-3-3β protein in increasing testosterone synthesis along with decreasing insulin sensitivity. Thus, 14-3-3β protein may be playing possible role in PCOS pathogenesis.

Effects of neonatal exposure to methoxychlor on corpus luteum in gilts: A transcriptomic analysis

This study investigated the effects of neonatal exposure to methoxychlor (MXC), a synthetic organochlorine used as an insecticide with estrogenic, antiestrogenic, and antiandrogenic activities, on luteal function in pigs. Piglets were injected subcutaneously with MXC (20 μg/kg body weight) or corn oil (control) between postnatal Days 1 and 10 (N = 5/group). Corpora lutea from sexually mature gilts were examined for luteal steroid and prostaglandin concentrations and processed for total RNA isolation and subsequent RNA sequencing. Intra-luteal concentrations of androstenedione and prostaglandin E₂ were greater, while that of estrone was lower when compared to control. Fifty-three differentially expressed (DE) microRNAS (miRNAs) (p-adjusted <.05 and log2(fold change) ≥.5) and 359 DE genes (p-adjusted <.05 and log2(fold change) ≥1) were identified in luteal tissue in response to neonatal MXC treatment. MXC was found to affect the expression of genes related to lipogenesis, steroidogenesis, membrane transport, immune response, cell signaling and adhesion. These results suggest an earlier onset of structural luteolysis in pigs caused by MXC actions in neonates. Since negative correlation analysis showed the potential interactions of miRNAs with specific messenger RNAs, we propose that these miRNAs are potential mediators of the long-term MXC effect on the CL function in pigs.

The effects of dexamethasone administered during pregnancy on the postpartum spiny mouse ovary

Excessive exposure to glucocorticoids can alter ovarian function by modulating oogenesis, folliculogenesis and steroidogenesis. The aim of the present study was to examine the effects of dexamethasone (DEX) administered during pregnancy on folliculogenesis and corpus luteum development in the postpartum spiny mouse ovary. DEX (125 μg kg^-1 body weight per day) was applied to pregnant spiny mouse from day 20 of gestation to parturition. The obtained ovaries were fixed and used for immunohistochemistry and TEM analysis. The expression of proteins related to apoptosis (caspase-3, Bax, Bcl-2) and autophagy (Beclin1, Lamp1) as well as PCNA and GR receptors were evaluated by western-blot. In comparison with DEX-treated group a higher percentage of TUNEL positive granulosa and luteal cells was observed in the control group. These data were consistent with changes in caspase-3 and Bax expression, which increased in the control and decreased after DEX exposure. In turn, the proliferation index and PCNA expression were higher in the DEX-treated group. Moreover, the higher level of Beclin1, Lamp1, anti-apoptotic Bcl-2 protein and GR was observed in the DEX-treated females than in the control group. Beclin1 and Lamp1 were strongly expressed in luteal cells which exhibited an autophagic ultrastructure. Surprisingly, DEX augmented the number of ovarian follicles and corpora lutea, which resulted in a significant increase in ovarian weight. These findings suggest that DEX exerts anti-apoptotic action on granulosa layer and stimulates follicular maturation. Moreover, DEX induces autophagy in luteal cells promoting cell survival rather than cell death, which can prolong the corpus luteum life span.