Involvement of progesterone and estrogen receptors in the ram sperm acrosome reaction.

The steroid hormones 17-ß estradiol (E2) and progesterone (P4) can regulate capacitation, hyperactive motility, and the acrosome reaction (AR) during the sperm transit through the female tract. Moreover, exogenous P4 and E2 can induce the AR in ovine spermatozoa, and progesterone receptor (PR) and estrogen receptors (ERα and ERß) are present in these cells. Thus, to investigate whether the effects both steroid hormones in ram sperm capacitation and AR are receptor-mediated, we incubated them with receptor agonists (tanaproget 1 µM and 5 µM for PR or resveratrol 5 µM and 10 µM for ER) or antagonists (mifepristone 4 µM and 40 µM for PR or tamoxifen 5 µM and 10 µM for ER) in capacitating conditions. The addition of receptor modulators did not affect sperm viability or total motility, although changes in progressive motility were detected. The incubation with both receptor agonists increased the percentage of acrosome-reacted spermatozoa, evaluated by chlortetracycline staining, when compared with the capacitated nontreated sample (Cap-C, P < 0.001). Moreover, the ER agonist resveratrol 10 µM provoked a greater AR than E2 (P < 0.01). Furthermore, the incubation with the receptor antagonists prevented the induction of the AR by P4 or E2, as the antagonists-treated spermatozoa presented a similar CTC pattern to that of Cap-C. In conclusion, these results confirm that P4 and E2 can induce the AR in ram spermatozoa and that this effect is receptor-mediated.

Underlying molecular mechanism in the modulation of the ram sperm acrosome reaction by progesterone and 17ß-estradiol.

Steroid hormones progesterone (P4) and 17ß-estradiol (E2) not only have important functions in regulation of reproductive processes in mammals but also have direct effects on spermatozoa. There can be induction of the acrosome reaction in ram spermatozoa by P4 and E2 and, in the present study, there was further investigation of mechanisms underlying this effect. In a medium containing agents that increase cAMP, the presence of both P4 and E2 led to changes in the localization of proteins phosphorylated in tyrosine residues evaluated by indirect immunofluorescence. The inclusion of P4 at 1 µM in the media induced an increase in Ca2+i and mobilization in the area of the acrosome (Fluo-4 and Rhod-5 staining, respectively), an increase in ROS (H2DCFDA staining) and a substantial disruption of the acrosome (evaluated using RCA), while E2 did not have these effects. There were no effects on cAMP concentrations or PKA activity with inclusion of these hormones in the media. The inclusion of P4 at 100 pM in the media led to changes in values for sperm kinematic variables which could indicate there was an inhibition of the hyperactivation caused by agents that induce an increase in cAMP concentrations. In conclusion, results from the present study indicate that P4 and E2 promote mechanisms regulating the acrosome reaction in ram spermatozoa, however, these effects on mechanisms are different for the two hormones, and for E2, require further clarification.

Steroid hormone receptors and direct effects of steroid hormones on ram spermatozoa.

This study was based on the assumption that steroid hormones present in the female genital tract may have a rapid effect on ram spermatozoa by interaction with specific surface receptors. We demonstrate the presence of progesterone (PR) and estrogen (ER) receptors in ram spermatozoa, their localization changes during in vitro capacitation and the actions of progesterone (P4) and 17ß-estradiol (E2) on ram sperm functionality. Immunolocalization assays revealed the presence of PR mainly at the equatorial region of ram spermatozoa. Western blot analyses showed three bands in ram sperm protein extracts of 40-45 kDa, compatible with those reported for PR in the human sperm membrane, and both classical estrogen receptors (66 kDa, ERα and 55 kDa, ERß). ERα was located in the postacrosomal region of all the spermatozoa and ERß on the apical region of 63.7% of the cells. The presence of ERß was correlated with the percentage of non-capacitated spermatozoa evaluated by chlortetracycline staining (R = 0.848, P < 0.001). This significantly decreased after in vitro capacitation and nearly disappeared when acrosome reaction was induced. The addition of P4 and E2 before in vitro capacitation resulted in a higher (P < 0.001) acrosome-reacted sperm rate compared with the control (13.0%), noticeably greater after 3 h and when added to a high-cAMP medium (37.3% and 47.0% with E2 and P4, respectively). In conclusion, the results of this study demonstrate for the first time that ovine spermatozoa have progesterone and estrogen receptors and that both steroid hormones are related with the induction of the acrosome reaction.

[Chromosomal anomalies: The experience of the Congenital Anomalies Registry of the Valencia Region]. / Anomalías cromosómicas: la experiencia del Registro de Anomalías Congénitas de la Comunitat Valenciana.

OBJECTIVE: To describe the temporal trend and distribution of chromosomal congenital abnormalities (CA) in the Valencia Region, in less than one year olds, during the period 2007-2011. METHODOLOGY: Live births, still births and termination of pregnancy due to foetal anomaly between 2007 and 2011 with chromosomal CA (Q90-Q99.9 codes of the 10th International Classification of Diseases -British Paediatric Association) were selected from the CA population-based Registry of Valencia Region The prevalence per 10,000 births for the chromosomal CA and for the different types of chromosomal syndromes with 95% confidence intervals was calculated. The analysis was performed by calculating prevalences and data were compared using Pearson Chi-squared test. RESULTS: A total of 895 cases were found, representing a prevalence of 33.5 per 10,000 births (95% CI: 31.0-35.9), highlighting five syndromes: Down's, Edward's, Patau, Turner and Klinefelter. The prevalence of chromosomal CA and Down's syndrome were stable over the period, except in 2010. Down's was the most frequent chromosomal CA (67% of the cases), and the most frequent termination of pregnancy type was for foetal anomaly (69%). Cardiac heart defects represented 70.3% of the associated congenital anomalies. Mothers of children with chromosomal CA were mainly Spanish (73.3%). The age group of mothers over 39 years had a higher prevalence (133.0 per 10,000 births). The province of Castellón had the highest prevalence, 39.1 per 10,000 births. CONCLUSIONS: The prevalence has remained stable over the five years, excluding the significant decline in 2010, for chromosomal CA detected and two of the major syndromes. The chromosomal CA are an important public health problem as they represent 15% of all CA identified in the Valencia Region, and agrees with the European data.