Tight interplay in early pregnancy between follistatin and anti-mullerian hormone in women with polycystic ovarian syndrome (PCOS)

PURPOSE

Follistatin levels increase during the course of pregnancy and may play a role in ovarian arrest, reflected by the simultaneous decrease of anti-mullerian-hormone (AMH) levels. The aim of the study was to investigate AMH and follistatin levels during the hormonal window at the beginning of pregnancy. Since both parameters are described as deregulated in polycystic ovarian syndrome (PCOS), subgroup analysis of PCOS patients may additionally elucidate their interplay and effects on ovarian activity.

METHODS

Serum samples were retrospectively analyzed using the AMH Gen II ELISA and the Human Follistatin Quantikine ELISA Kit. Samples were collected longitudinally from 57 patients (32 with PCOS and 25 controls) before conception and during the first trimester. In 18 patients, measurements from the early and the late first trimester were available. Potential associations of AMH and follistatin levels with PCOS-related parameters were compared between the subgroups as well as longitudinally before and in the first trimester of pregnancy. For statistical analysis, the Spearman's correlation, Wilcoxon test, t test, Friedman test and multiple linear regression analysis was performed.

RESULTS

In contrast to AMH, follistatin levels differed not between controls and PCOS patients before and in pregnancy. In both subgroups, AMH levels significantly decreased and follistatin levels significantly increased in longitudinally performed measurements before conceiving and in the first trimester of pregnancy.

CONCLUSION

Follistatin levels are not suited as a biomarker for PCOS, but could be involved in suppressing ovarian activity, as reflected by AMH levels at the beginning of pregnancy.

Placental and maternal serum activin A in spontaneous and induced labor in late-term pregnancy

PURPOSE

Feto-placental unit represents an important source of activin A, a member of transforming growth factors-β involved in the mechanisms of labor. No evidences are available on activin A in pregnancies beyond 41 weeks of gestation, where induction of labor is often required. The present study aimed to evaluate activin A maternal serum levels and placental mRNA expression in term and late-term pregnancy, with spontaneous or induced labor, and its possible role to predict the response to labor induction.

METHODS

Maternal serum samples and placental specimens were collected from women with singleton pregnancy admitted for either term spontaneous labor (n = 23) or induction of labor for late-term pregnancy (n = 41), to evaluate activin A serum levels and placental mRNA expression. Univariate and multivariate analyses on activin A serum levels, maternal clinical parameters, and cervical length were conducted in women undergoing induction of labor.

RESULTS

Maternal serum activin A levels and placental activin A mRNA expression in late-term pregnancies were significantly higher than at term. Late-term pregnancies who did not respond to induction of labor showed significantly lower levels of activin A compared to responders. The combination of serum activin A and cervical length achieved a sensitivity of 100% and a specificity of 93.55% for the prediction of successful induction.

CONCLUSION

Late-term pregnancy is characterized by hyperexpression of placental activin A and increased maternal activin A secretion. By combining maternal serum activin A levels with cervical length, a good predictive model for the response to induction of labor was elaborated.

Acute regulation of activin A and its binding protein, follistatin, in serum and tissues following lipopolysaccharide treatment of adult male mice

Activin A, a member of the transforming growth factor-β family, increases in the circulation within 1 h after administration of bacterial LPS. To clarify the origins of this rapid increase, the distribution of activin A and its binding protein, follistatin, and their production following LPS treatment, were assessed in adult male mice. In untreated mice, activin A was detectable in all 23 tissues examined, with highest mRNA expression (as measured by quantitative RT-PCR) was found in the liver, and the largest concentration of activin A protein (by ELISA) was found in the bone marrow. Likewise, follistatin mRNA and protein were present in all tissues, with highest expression in the vas deferens. Activin A and follistatin mRNA did not increase significantly in any tissue within the first hour after LPS, but activin A protein decreased by 35% in the bone marrow and increased 5-fold in the lung. No significant changes were observed in any other tissue. Activin A reached a peak in the circulation 1 h following LPS, and then declined. Cycloheximide, an inhibitor of protein translation, reduced this increase of activin A by more than 50%. Actinomycin D, an inhibitor of mRNA transcription, had no effect. Circulating follistatin did not increase until 4 h after LPS and was not affected by either inhibitor. These data indicate that the rapid increase in circulating activin A during LPS-induced inflammation is regulated at the posttranscriptional level, apparently from newly translated and stored protein, and implicate bone marrow-derived cells, and, in particular, neutrophils, as a significant source of this preformed activin A.

Activin A as a marker of intrauterine infection in women with preterm prelabour rupture of membranes

OBJECTIVE

To assess maternal serum activin A, an early phase response protein in systemic infection, as an early marker of intrauterine infection in women with preterm prelabour rupture of membranes (PPROM).

STUDY DESIGN

A prospective cohort study of women with singleton pregnancies complicated by PPROM at 24 to 34 weeks' gestation. Serum was collected for activin A and cytokine measurements. Activin A was measured using commercial enzyme-linked immunosorbent assay. Cytokines were measured using commercial multiplex assay. Pregnancy outcomes including infection were determined by case-record review.

RESULT

Eighteen women with PPROM were studied, with seven developing intrauterine infection. Serum activin A in women with and without infection did not differ. Peripheral white cell count, interleukin (IL)-6 and IL-10 were higher (P=0.03, 0.05 and 0.009, respectively) and IL-7 lower (P=0.04) 72 h before delivery in women with infection.

CONCLUSION

Activin A is not a clinically useful marker of intrauterine infection in women with PPROM.

Placental production and maternal serum and urine levels of inhibin A and activin A are modified by antihypertensive therapy in hypertensive disorders of pregnancy

OBJECTIVE

Levels of inhibin A and activin A are raised in pre-eclampsia (PE) but it is not known if antihypertensive therapy can affect their levels. Our aim was to investigate the effect of the antihypertensive drug alpha-methyldopa on serum, urine and placental concentrations of inhibin A and activin A in women presenting with hypertensive disorders of pregnancy.

DESIGN

This was a cross-sectional study.

PATIENTS

We recruited 65 women presenting with PE, 39 with gestational hypertension (GH) and 104 normotensive controls matched for maternal age, gestational age and parity.

MEASUREMENTS

Using specific validated ELISAs, serum and urine levels of inhibin A and activin A, and uterine artery Doppler indices, were measured before and 24-48 h after initiating alpha-methyldopa therapy in women with PE, with GH and controls. Protein extracts were obtained from samples of placental tissue from another group of women with PE, GH and controls for the same analysis.

RESULTS

In PE, but not GH, alpha-methyldopa therapy was associated with significantly (P < 0.05) lower levels of both serum and urine inhibin A and activin A. Similarly, in PE but not GH, alpha-methyldopa therapy was associated with lower placental levels of both markers (P < 0.05). There was no significant difference in pulsatility index following treatment in either PE or GH.

CONCLUSIONS

Our data indicate that antihypertensive therapy with alpha-methyldopa may have an effect on the synthesis and/or release of placental proteins in pregnancies complicated by PE and that this effect may be independent of its known antihypertensive action.

Follistatin serum concentrations during full-term labour in women – significant differences between spontaneous and induced labour

Follistatin has been isolated from human placenta and has been identified in human foetal membranes and fluids. Serum follistatin levels in women rise during pregnancy particularly near term. In this study, we examined the effect of induction and stage of labour on maternal plasma concentrations of follistatin. Women who gave birth after a normal pregnancy were retrospectively divided into three groups: those who went in labour spontaneously (n= 33), needed induction by amniotomy and IV oxytocin (n= 18) or underwent planned caesarean section (n= 10). Serum was collected at 38–40 weeks of gestation, periodically through labour with a vaginal examination and once within 36 h postpartum and assayed for oestradiol, progesterone, prolactin and C-reactive protein. Follistatin was measured using a rabbit antiserum (#204) raised against purified 35 kDa bovine follistatin. Human recombinant follistatin was used as both standard and tracer. Concentrations of follistatin at 38–40 weeks of gestation were significantly different between groups. Those who had a spontaneous labour had concentrations higher than those who were induced. Similarly, those who were induced had concentrations higher than those who underwent a caesarean. In the spontaneous group, follistatin rose during labour, peaking at 57.9 ± 5.48 ng/ml at > 3 cm of cervical dilation, and after delivery follistatin decreased to 26.16 ± 3.4 ng/ml at 24 h post-delivery. In induced patients follistatin continued increasing to peak following delivery at 26.9 ± 3.0 ng/ml and decreased at > 3 h post-delivery. Follistatin concentrations in caesarean section patients at 24 h post-surgery (18.53 ± 3.74 ng/ml) were not different from that before the surgery and were comparable with the other two groups. Follistatin is clearly implicated in the onset of labour; however, further studies with a larger cohort of women are necessary to determine the nature of its role.

Inhibition of amino acid transport system a by interleukin-1beta in trophoblasts

OBJECTIVE

The current study sought to investigate the influence of interleukin-1beta (IL-1beta) on the function of the amino acid transport system A in trophoblasts.

METHODS

BeWo choriocarcinoma cells were exposed to recombinant human IL-1beta in serum-free medium. Cells incubated with serum-free medium in the absence of IL-1beta were used as control. System A activity was determined in control and treated cells by measuring the uptake of alpha-(methylamino)isobutyric acid. The results obtained were confirmed by measuring system A activity in placental brush border membrane vesicles isolated from pregnant rats injected with IL-1beta.

RESULTS

Treatment of BeWo cells with IL-1beta resulted in a time- and dose- dependent inhibition of system A. Treatment with IL-1beta also inhibited the uptake of arginine, and glutamate but had no significant effect on the uptake of leucine, tryptophan, and ascorbate. The inhibition of system A activity by IL-1beta was abolished in the presence of IL-1beta receptor antagonist. The inhibitory effect was associated with a decrease in the maximal velocity of the transport system with no effect on the substrate affinity. Steady-state levels of both SNAT1 and SNAT2 mRNA were reduced by IL-1beta treatment as evidenced by semiquantitative reverse transcriptase-polymerase chain reaction (RT-PCR) analysis. In rat placental brush border membrane vesicles isolated from IL-1beta-treated pregnant rats, system A activity was found to be decreased by approximately 40% compared to activity in control membrane vesicles.

CONCLUSIONS

IL-1beta decreases SNAT1 and SNAT2 mRNA levels in trophoblasts, which is associated with a decrease in system A-mediated transport activity at the functional level. These findings may have important consequences under both physiologic conditions and pathologic conditions during pregnancy that are associated with elevated levels of IL-1beta.

Predictive value of hormone measurements in maternal and fetal complications of pregnancy

Intrauterine tissues (placenta, amnion, chorion, decidua) express hormones and cytokines that play a decisive role in maternal-fetal physiological interactions. The excessive or deficient release of some placental hormones in association with gestational diseases may reflect an abnormal differentiation of the placenta, an impaired fetal metabolism, or an adaptive response of the feto-placental unit to adverse conditions. This review is focused on the applicability of hormone measurements in the risk assessment, early diagnosis, and management of pregnancies complicated by Down's syndrome, fetal growth restriction, preeclampsia, preterm delivery, and diabetes mellitus. Combined hormonal tests or the combination of hormones and ultrasound may achieve reasonable sensitivity, but research continues to simplify the screening programs without sacrificing their accuracy. Only in a few instances is there sufficient evidence to firmly recommend the routine use of hormone tests to predict maternal and fetal complications, but the judicious use of selected tests may enhance the sensitivity of the risk assessment based solely on clinical and ultrasound examination.