The progesterone derivative dydrogesterone abrogates murine stress-triggered abortion by inducing a Th2 biased local immune response

The effects of progesterone on immune cellular function at the maternal-fetal interface and in maternal circulation

Progesterone is a sex steroid hormone that plays a critical role in the establishment and maintenance of pregnancy. This hormone drives numerous maternal physiological adaptations to ensure the continuation of pregnancy and to facilitate fetal growth, including broad and potent modulation of the maternal immune system to promote maternal-fetal tolerance. In this brief review, we provide an overview of the immunomodulatory functions of progesterone in the decidua, placenta, myometrium, and maternal circulation during pregnancy. Specifically, we summarize current evidence of the regulated functions of innate and adaptive immune cells induced by progesterone and its downstream effector molecules in these compartments, including observations in human pregnancy and in animal models. Our review highlights the gaps in knowledge of interactions between progesterone and maternal cellular immunity that may direct future research.

Hyperglycaemia, pregnancy outcomes and maternal metabolic disease risk during pregnancy and lactation in a lean gestational diabetes mouse model

Hyperglycaemia in pregnancy (HIP) is a pregnancy complication characterized by mild to moderate hyperglycaemia that negatively impacts short- and long-term health of mother and child. However, relationships between severity and timing of pregnancy hyperglycaemia and postpartum outcomes have not been systemically investigated. We investigated the impact of hyperglycaemia developing during pregnancy (gestational diabetes mellitus, GDM) or already present pre-mating (pre-gestational diabetes mellitus, PDM) on maternal health and pregnancy outcomes. GDM and PDM were induced in C57BL/6NTac mice by combined 60% high fat diet (HF) and low dose streptozotocin (STZ). Animals were screened for PDM prior to mating, and all underwent an oral glucose tolerance test on gestational day (GD)15. Tissues were collected at GD18 or at postnatal day (PN)15. Among HFSTZ-treated dams, 34% developed PDM and 66% developed GDM, characterized by impaired glucose-induced insulin release and inadequate suppression of endogenous glucose production. No increased adiposity or overt insulin resistance was observed. Furthermore, markers of non-alcoholic fatty liver disease (NAFLD) were significantly increased in PDM at GD18 and were positively correlated with basal glucose levels at GD18 in GDM dams. By PN15, NAFLD markers were also increased in GDM dams. Only PDM affected pregnancy outcomes such as litter size. Our findings indicate that GDM and PDM, resulting in disturbances of maternal glucose homeostasis, increase the risk of postpartum NAFLD development, related to the onset and severity of pregnancy hyperglycaemia. These findings signal a need for earlier monitoring of maternal glycaemia and more rigorous follow-up of maternal health after GDM and PDM pregnancy in humans. KEY POINTS: We studied the impact of high-fat diet/streptozotocin induced hyperglycaemia in pregnancy in mice and found that this impaired glucose tolerance and insulin release. Litter size and embryo survival were compromised by pre-gestational, but not by gestational, diabetes. Despite postpartum recovery from hyperglycaemia in a majority of dams, liver disease markers were further elevated by postnatal day 15. Maternal liver disease markers were associated with the severity of hyperglycaemia at gestational day 18. The association between hyperglycaemic exposure and non-alcoholic fatty liver disease signals a need for more rigorous monitoring and follow-up of maternal glycaemia and health in diabetic pregnancy in humans.

Association of maternal temperament and offspring disposition on growth performance

Animal behavior is complex and varies in definition, depending upon specific traits under observation. Temperament is one component of behavior, that in cattle, is described as the level of fearfulness to a novel or threatening environment. Temperament is a heritable trait which is important since aggressiveness and docility contribute to reproductive success, growth, and carcass quality. We observed maternal temperament at calving and the subsequent influence, if any, on offspring disposition at weaning and their effects collectively on growth performance and carcass traits. Maternal behaviors at calving were observed at four locations within the University of Arkansas system. Cows were assigned a maternal disposition score (MDS) at calving; a scale from 1 to 5 in which aggression decreases. At weaning, calves were assigned a chute score (CS); a scale from 1 to 6 in which aggression increases. Both scoring systems have been previously established. Blood was collected during the 56-d backgrounding period postweaning for blood glucose analysis. Data were analyzed using GLIMMIX procedures of SAS (α = 0.05). The relationship between the two scoring systems was determined with a Pearson correlation (P = 0.22). Animal was the experimental unit and blocked by location for all dependent variables. Location, sex, diet, and MDS were included in the class as covariables for all growth performance and carcass data related to CS. Cows that were more aggressive birthed heavier calves (P < 0.01) compared to indifferent cows. Calves born to cows with either very aggressive or very attentive (MDS of 2 or 3, respectively) scores were heavier upon feedlot entry (P = 0.03) compared to those from indifferent or apathetic cows (MDS of 4 or 5, respectively). Calves defined as nervous and restless (CS of 3 and 2, respectively) were heavier at weaning compared to docile calves (P < 0.01). Restless calves were heavier compared to nervous calves upon arrival and exiting the feedlot (P ≤ 0.01). Calves that were docile at weaning had greater marbling compared to calves that were restless (P ≤ 0.01). Calves that were restless at weaning had greater lean muscle area compared to calves that were nervous (P = 0.05). No definitive relationship was determined between dam and calf temperament. However, the results suggest temperament does impact growth performance and carcass traits but whether the influence comes from the dam or calf temperament, specifically, remains unanswered.

Design, synthesis, and biological activities of novel thiophene, pyrimidine, pyrazole, pyridine, coumarin and isoxazole: Dydrogesterone derivatives as antitumor agents

On the basis of our consideration to design and to develop antitumor activities of heterocyclic compound derivatives, especially in fused ring system, we refer to the possibility of the heterocyclic extension of one of the most important steroid compounds used as a medicinal drug. The reaction of dydrogesterone with each of the malononitrile or ethylcyanoacetate containing elemental sulfur afforded thiophene derivatives 1a,b. Also, dydrogesterone was reacted with a mixture of ethylcyanoacetate–hydrazine, ethylcyanoacetae–urea, or ethylcyanoacetate–thiourea to produce pyrazole derivative 4 and pyrimidine derivatives 5a,b. Thienopyrimidine derivatives 2a–d were introduced from the reaction of thiophene derivatives 1a,b with either phenylisothiocyanate or benzoylisothioyanate. Furthermore, compounds 1a,b were directed toward the reaction with ethylcyanoacetate to produce compounds 6a,b, and the last compounds 6a,b were directed toward cyclization to obtain thienopyridine derivatives 7a,b. In addition, compounds 6a,b were subjected to react with different carbonyl compounds, such as salicylaldehyde, cyclopentanone-elemental sulfur, malonaldehyde, and acetylacetone to produce coumarin derivatives 8a,b, fused thiophene derivatives 9a,b, and pyridine derivatives 10a–d. Isooxazole derivatives 12a,b were afforded through the reaction of compounds 6a,b with hydroxylamine hydrochloride. Finally, 2-pyridone derivatives 14a,b were obtained through the reaction of compounds 6a,b with benzoylacetonitrile. Conformation structure of the synthesized compounds was established by applying IR, 1H NMR, 13C NMR, and mass spectrometry, and their antitumor activity was examined. Some compounds showed promising growth inhibitory effects on the three different cell lines.

Inflammatory conditions promote a switch of oligosaccharyltransferase (OST) catalytic subunit isoform expression

Oligosaccharyltransferase (OST) complex catalyzes the N-glycosylation of nascent polypeptides in the endoplasmic reticulum. Glycoproteins are critical for normal cell-cell interactions, especially during an immune response. Abnormal glycosylation is an insignia of several inflammatory diseases. However, the mechanisms that regulate the differential N-glycosylation are not fully understood. The OST complex can be assembled with one out of two catalytic subunits, STT3A or STT3B, which have different enzymatic properties. In this work, we investigated the expression of STT3A and STT3B in several mouse models such as a crossbreeding of normal and abortion-prone mice and an intestinal inflammation model. These animals were either exposed or not to acoustic stress (acute or chronic). The expression of the isoforms was analysed by immunohistochemistry and protein immunoblot. Finally, we investigated the gene regulatory elements employing public databases. Results demonstrated that inflammation alters the balance between the expression of both isoforms in the affected tissues. In homoeostatic conditions, STT3A expression predominates over STT3B, especially in epithelial cells. This relation is reversed as a consequence of inflammation. An increase in STT3B activity was associated to the generation of mannose-rich N-glycans. Accordingly, this type of N-glycans were found to decorate diverse inflamed tissues. The STT3A and STT3B genes are differentially regulated, which could account for the differences in the expression levels observed here. Our results support the idea that these isoforms could play different roles in cellular physiology. This study opens the possibility of studying the STT3A/STT3B expression ratio as a biomarker in acute inflammation or chronic diseases.

Stress, Sex, and Sugar: Glucocorticoids and Sex-Steroid Crosstalk in the Sex-Specific Misprogramming of Metabolism

Early-life exposures to environmental insults can misprogram development and increase metabolic disease risk in a sex-dependent manner by mechanisms that remain poorly characterized. Modifiable factors of increasing public health relevance, such as diet, psychological stress, and endocrine-disrupting chemicals, can affect glucocorticoid receptor signaling during gestation and lead to sex-specific postnatal metabolic derangements. Evidence from humans and animal studies indicate that glucocorticoids crosstalk with sex steroids by several mechanisms in multiple tissues and can affect sex-steroid-dependent developmental processes. Nonetheless, glucocorticoid sex-steroid crosstalk has not been considered in the glucocorticoid-induced misprogramming of metabolism. Herein we review what is known about the mechanisms by which glucocorticoids crosstalk with estrogen, androgen, and progestogen action. We propose that glucocorticoid sex-steroid crosstalk is an understudied mechanism of action that requires consideration when examining the developmental misprogramming of metabolism, especially when assessing sex-specific outcomes.

Altered crosstalk of estradiol and progesterone with Myeloid-derived suppressor cells and Th1/Th2 cytokines in early miscarriage is associated with early breakdown of maternal-fetal tolerance

PROBLEM

Decline in myeloid-derived suppressor cells (MDSCs) and Th2 cytokines levels lead to early miscarriage (EM) but how the hormonal milieu of the body regulates MDSCs and Th1/Th2 cytokine balance is still a matter of investigation.

METHOD OF STUDY

Peripheral blood and decidua samples were collected from 20 EM patients, and 20 healthy pregnant women opted for elective abortion. MDSCs and G-MDSCs levels were analyzed in peripheral blood mononuclear cells, and Th1/Th2 cytokines levels were determined in serum via flow cytometry. Estrogen (E2), Progesterone (P4), and Testosterone levels were measured via ELISA. Further, proliferation and apoptosis in decidual samples were checked via immunoblot/immunohistochemistry of estrogen receptor -α (ER-α), STAT-3/pSTAT-3, and caspase-3, respectively.

RESULTS

Our results clearly indicate that in EM patients; decline in E2 and P4 significantly correlates with decline in MDSCs, particularly with subtype granulocytic MDSCs (G-MDSCs) and skewness of the Th1/Th2 cytokines balance toward Th1 response. Downregulation of ER- α and increased caspase-3 expression in endometrium decidua signifies poor endometrial receptivity in EM. STAT-3 activation regulates proliferation, differentiation and suppressive potency of MDSCs. In decidua of EM, significantly lower expression of pSTAT-3 indicates that these processes pertaining to MDSCs are compromised.

CONCLUSION

Altogether, this unfavorable systemic milieu may drive toward early breakdown of maternal-fetal tolerance in EM. Therefore, regulated crosstalk of E2, P4 with MDSCs and balanced Th1/Th2 cytokines is prerequisite for successful pregnancy.

New data about preeclampsia: some possibilities of prevention

This concise report deals with the known effects of progestogen lack in early pregnancy with failure of implantation and blood supply to the placenta depending on proper trophoblast invasion, spiral artery remodeling, and vessel dilatation. The pathophysiology of preeclampsia will be outlined and the most recent data on the effect of dydrogesterone presented. Dydrogesterone appears to be able to reduce significantly the development of preeclampsia. The effect is related to begin with such prevention and this should be continued until 37th weeks of gestation which would also mean prevention of premature labor.

Incidence and biomarkers of pregnancy, spontaneous abortion, and neonatal loss during an environmental stressor: Implications for female reproductive suppression in the cooperatively breeding meerkat

Meerkats are group-living, insectivorous herpestids in which subordinate members provide extensive care for the dominant female's young. In contrast to some cooperative breeders, subordinate female meerkats are physiologically able to reproduce and occasionally do so successfully; their attempts are more frequently 'suppressed' via eviction or infanticide by the dominant female. Spontaneous abortion and neonatal loss occur with some regularity, further negatively impacting reproductive success. Here, we compared the reproductive outcomes and endocrine profiles, including of serum progesterone (P₄), serum estradiol (E₂), and fecal glucocorticoid metabolites (fGCm), of dominant and subordinate dams residing within their clans in the Kalahari Desert of South Africa. Our study spanned years of drought, which reduced insect abundance and represented a substantial environmental stressor. Meerkat pregnancies were identified at mid-term and culminated either in spontaneous abortions or full-term deliveries, after which pups were either lost prior to emergence from the natal den (usually within 2days of birth) or emerged at 2-3weeks. Neonatal loss exceeded fetal loss for all females, and contributed to narrowing the status-related disparity in female reproductive output seen during less arid periods. Although E₂ concentrations were significantly lower in subordinate than dominant females, they were sufficient to support gestation. Absolute E₂ concentrations may owe to androgenic precursors that also attain highest concentrations in dominant dams and may mediate aggression underlying female reproductive skew. Pregnancies terminating in fetal loss were marked by significantly lower P₄ concentrations in mid-gestation and modestly lower E₂ concentrations overall. Consistently high fGCm concentrations further increased across trimesters, particularly (but not consistently) in subordinates and in aborted pregnancies. Environmental stressors may modulate reproductive outcomes in meerkats through their influence on sex steroids and their effects on intragroup competition. The social and eco-physiological factors affecting intraspecific variation in reproductive output, even in obligate cooperative breeders, may be most apparent during extreme conditions, reflecting the benefits of long-term studies for assessing the impact of climate change.

Mesenchymal Stem Cell Therapy Prevents Abortion in CBA/J × DBA/2 Mating

Immunological disorders are among the main causes of recurrent spontaneous abortions (RSAs). Mesenchymal stem cells (MSCs) have been shown to modulate various aspects of immune responses. It seems that MSCs may improve the immunological conditions in immune-mediated RSA. The aim of this study is the reduction of resorption in RSA mouse model through MSCs therapy. The adipose-derived MSCs were administered intraperitoneal to pregnant CBA/J mice on day 4.5 of gestation in abortion-prone matting. On day 13.5 of pregnancy, abortion rates were calculated and transforming growth factor-β (TGF-β), interleukin 10 (IL-10), interferon γ (IFN-γ), and tumor necrosis factor α (TNF-α) gene expression in deciduas were evaluated by real-time polymerase chain reaction (PCR). The level of TGF-β in serum was also determined by enzyme linked immunosorbent assay (ELISA) method. The obtained results showed that MSCs therapy could reduce the abortion rate significantly in test group compared to controls. MSCs therapy also caused a significant upregulation of TGF-β and IL-10 and downregulation of IFN-γ and TNF-α genes expression in deciduas. However, the levels of TGF-β didn't change in mice sera. Due to the significant decrease in abortion rate, we concluded that MSCs therapy could modulate the immune responses in fetomaternal interface and protect fetus from undesirable immune responses. So, these cells might be considered as a new therapeutic for spontaneous pregnancy loss. The local upregulation of TGF-β and IL-10 and downregulation of IFN-γ and TNF-α gene expression in decidua could be considered as one possible mechanism of immune regulation, which could protect the fetus.

Linking Stress and Infertility: A Novel Role for Ghrelin

Infertility affects a remarkable one in four couples in developing countries. Psychological stress is a ubiquitous facet of life, and although stress affects us all at some point, prolonged or unmanageable stress may become harmful for some individuals, negatively impacting on their health, including fertility. For instance, women who struggle to conceive are twice as likely to suffer from emotional distress than fertile women. Assisted reproductive technology treatments place an additional physical, emotional, and financial burden of stress, particularly on women, who are often exposed to invasive techniques associated with treatment. Stress-reduction interventions can reduce negative affect and in some cases to improve in vitro fertilization outcomes. Although it has been well-established that stress negatively affects fertility in animal models, human research remains inconsistent due to individual differences and methodological flaws. Attempts to isolate single causal links between stress and infertility have not yet been successful due to their multifaceted etiologies. In this review, we will discuss the current literature in the field of stress-induced reproductive dysfunction based on animal and human models, and introduce a recently unexplored link between stress and infertility, the gut-derived hormone, ghrelin. We also present evidence from recent seminal studies demonstrating that ghrelin has a principal role in the stress response and reward processing, as well as in regulating reproductive function, and that these roles are tightly interlinked. Collectively, these data support the hypothesis that stress may negatively impact upon fertility at least in part by stimulating a dysregulation in ghrelin signaling.

Rhythmic Three-Part Harmony: The Complex Interaction of Maternal, Placental and Fetal Circadian Systems

From the perspective of circadian biology, mammalian pregnancy presents an unusual biological scenario in which an entire circadian system (i.e., that of the fetus) is embodied within another (i.e., that of the mother). Moreover, both systems are likely to be influenced at their interface by a third player, the placenta. Successful pregnancy requires major adaptations in maternal physiology, many of which involve circadian changes that support the high metabolic demands of the growing fetus. A functional role for maternal circadian adaptations is implied by the effects of circadian disruption, which result in pregnancy complications including higher risks for miscarriage, preterm labor, and low birth weight. Various aspects of fetal physiology lead to circadian variation, at least in late gestation, but it remains unclear what drives this rhythmicity. It likely involves contributions from the maternal environment and possibly from the placenta and the developing intrinsic molecular clocks within fetal tissues. The role of the placenta is of particular significance because it serves not only to relay signals about the external environment (via the mother) but may also exhibit its own circadian rhythmicity. This review considers how the fetus may be influenced by dynamic circadian signals from the mother and the placenta during gestation, and how, in the face of these changing influences, a new fetal circadian system emerges. Particular emphasis is placed on the role of endocrine signals, most notably melatonin and glucocorticoids, as mediators of maternal-fetal circadian interactions, and on the expression of the clock gene in the 3 compartments. Further study is required to understand how the mother, placenta, and fetus interact across pregnancy to optimize circadian adaptations that support adequate growth and development of the fetus and its transition to postnatal life in a circadian environment.

Acoustic stress induces long term severe intestinal inflammation in the mouse

The influence of noise on the presentation and progression of inflammatory bowel diseases has been poorly analyzed. We designed this study to investigate immediate and late effects of acoustic stress (AS) on small intestine. To this aim, CBA/J, BALB/c and DBA/2 mice were divided into AS and control groups. AS mice were exposed to noise (300Hz-70dB) during 24hs and randomized into: A) Acute effects group: mice were killed after AS; L) Late effects group: mice were killed 3 weeks after AS and O) Over-exposed effects group: mice were submitted to AS once a week during a month and killed. Small intestine sections were histologically examined. The expression of cytokines (IL-17, IL-22, TNF-α, INF-ɣ and TGF-β), CCL-25 and Ki67 was studied by immunohistochemistry and immunofluorescence techniques. "A" group displayed short and fragmented villi, diminished number of lamina propria cells, leucocyte infiltration, higher number of goblet cells and predominance of IL-17 expression. "L" group showed epithelial proliferative foci (CCL25+Ki67+) and increased TNFα/TGF-β expression. Tissue damage was aggravated in "O" group. In conclusion, AS is able to trigger a severe intestinal inflammatory process in healthy mice, which spontaneously amplifies and perpetuates. Noise might be harmful to humans by aggravating inflammatory bowel diseases.

The Adverse Effects of Auditory Stress on Mouse Uterus Receptivity and Behaviour

Stress during gestation has harmful effects on pregnancy outcome and can lead to spontaneous abortion. Few studies, however, have addressed the impact of gestational stress, particularly auditory stress, on behavioural performance and pregnancy outcome in mice. This study aimed to examine the effect of two types of gestational stress on uterus receptivity and behavioural performance. Pregnant C57BL/6 mice were randomly assigned to either auditory or physical stress conditions or a control condition from gestational days 12-16. The auditory stress regimen used loud 3000 Hz tone, while the physical stressor consisted of restraint and exposure to an elevated platform. Three behavioural tests were performed in the dams after weaning. Uterine receptivity was investigated by counting the number of sites of implantation and fetal resorption. Also, the offspring survival rates during the early postnatal period were calculated. Auditory stress caused an increase in anxiety-like behaviour, reduced time spent exploring new object/environment, and reduced balance when compared to the physical stress and control groups. Auditory stress also caused higher rates of resorbed embryos and reduction of litter size. Our results suggest that the adverse effect of noise stress is stronger than physical stress for both uterus receptivity and behavioural performance of the dams.

A randomized double-blind controlled trial of the use of dydrogesterone in women with threatened miscarriage in the first trimester: study protocol for a randomized controlled trial

Background

Miscarriage is a common complication of pregnancy occurring in 15–20 % of all clinically recognized pregnancies. Currently, there is still no good scientific evidence to support the routine use of progestogens for the treatment of threatened miscarriage because the existing studies were not large enough to show a significant difference and some of them were not randomized or double-blind.

Methods

This is a double-blind, randomized controlled trial. A total of 400 patients presenting with first-trimester threatened miscarriage will be enrolled. They will be randomized to take dydrogesterone 40 mg per os, followed by 10 mg per os three times a day or placebo until twelve completed weeks of gestation or 1 week after the bleeding has stopped, whichever is longer. The primary outcome is the percentage of miscarriage before 20 weeks of gestation.

Discussion

We postulate that the dydrogesterone therapy will significantly reduce the risk of miscarriage in women with threatened miscarriage.

Trial registration

This study is registered at ClinicalTrials.gov, NCT02128685. Registered on 29 April 2014.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-016-1509-8) contains supplementary material, which is available to authorized users.

Differential mouse-strain specific expression of Junctional Adhesion Molecule (JAM)-B in placental structures

The junctional adhesion molecule (JAM)-B, a member of the immunoglobulin superfamily, is involved in stabilization of interendothelial cell-cell contacts, formation of vascular tubes, homeostasis of stem cell niches and promotion of leukocyte adhesion and transmigration. In the human placenta, JAM-B protein is abundant and mRNA transcripts are enriched in first-trimester extravillous trophoblast in comparison to the villous trophoblast. We here aimed to elucidate the yet unexplored spatio-temporal expression of JAM-B in the mouse placenta. We investigated and semi-quantified JAM-B protein expression by immunohistochemistry in early post-implantation si tes and in mid- to late gestation placentae of various murine mating combinations. Surprisingly, the endothelium of the placental labyrinth was devoid of JAM-B expression. JAM-B was mainly present in spongiotrophoblast cells of the junctional zone, as well as in the fetal vessels of the chorionic plate, the umbilical cord and in maternal myometrial smooth muscle. We observed a strain-specific placental increase of JAM-B protein expression from mid- to late gestation in Balb/c-mated C57BL/6 females, which was absent in DBA/2J-mated Balb/c females. Due to the essential role of progesterone during gestation, we further assessed a possible modulation of JAM-B in mid-gestational placentae deficient in the progesterone receptor (Pgr(-/-)) and observed an increased expression of JAM-B in Pgr(-/-) placentae, compared to Pgr(+/+) tissue samples. We propose that JAM-B is an as yet underappreciated trophoblast lineage-specific protein, which is modulated via the progesterone receptor and shows unique strain-specific kinetics. Future work is needed to elucidate its possible contribution to placental processes necessary to ensuring its integrity, ultimately facilitating placental development and fetal growth.

Progesterone and HMOX-1 promote fetal growth by CD8+ T cell modulation

Intrauterine growth restriction (IUGR) affects up to 10% of pregnancies in Western societies. IUGR is a strong predictor of reduced short-term neonatal survival and impairs long-term health in children. Placental insufficiency is often associated with IUGR; however, the molecular mechanisms involved in the pathogenesis of placental insufficiency and IUGR are largely unknown. Here, we developed a mouse model of fetal-growth restriction and placental insufficiency that is induced by a midgestational stress challenge. Compared with control animals, pregnant dams subjected to gestational stress exhibited reduced progesterone levels and placental heme oxygenase 1 (Hmox1) expression and increased methylation at distinct regions of the placental Hmox1 promoter. These stress-triggered changes were accompanied by an altered CD8+ T cell response, as evidenced by a reduction of tolerogenic CD8+CD122+ T cells and an increase of cytotoxic CD8+ T cells. Using progesterone receptor- or Hmox1-deficient mice, we identified progesterone as an upstream modulator of placental Hmox1 expression. Supplementation of progesterone or depletion of CD8+ T cells revealed that progesterone suppresses CD8+ T cell cytotoxicity, whereas the generation of CD8+CD122+ T cells is supported by Hmox1 and ameliorates fetal-growth restriction in Hmox1 deficiency. These observations in mice could promote the identification of pregnancies at risk for IUGR and the generation of clinical interventional strategies.

Glucocorticoid Regulation of Reproduction

It is well accepted that stress, measured by increased glucocorticoid secretion, leads to profound reproductive dysfunction. In times of stress, glucocorticoids activate many parts of the fight or flight response, mobilizing energy and enhancing survival, while inhibiting metabolic processes that are not necessary for survival in the moment. This includes reproduction, an energetically costly procedure that is very finely regulated. In the short term, this is meant to be beneficial, so that the organism does not waste precious energy needed for survival. However, long-term inhibition can lead to persistent reproductive dysfunction, even if no longer stressed. This response is mediated by the increased levels of circulating glucocorticoids, which orchestrate complex inhibition of the entire reproductive axis. Stress and glucocorticoids exhibits both central and peripheral inhibition of the reproductive hormonal axis. While this has long been recognized as an issue, understanding the complex signaling mechanism behind this inhibition remains somewhat of a mystery. What makes this especially difficult is attempting to differentiate the many parts of both of these hormonal axes, and new neuropeptide discoveries in the last decade in the reproductive field have added even more complexity to an already complicated system. Glucocorticoids (GCs) and other hormones within the hypothalamic-pituitary-adrenal (HPA) axis (as well as contributors in the sympathetic system) can modulate the hypothalamic-pituitary-gonadal (HPG) axis at all levels-GCs can inhibit release of GnRH from the hypothalamus, inhibit gonadotropin synthesis and release in the pituitary, and inhibit testosterone synthesis and release from the gonads, while also influencing gametogenesis and sexual behavior. This chapter is not an exhaustive review of all the known literature, however is aimed at giving a brief look at both the central and peripheral effects of glucocorticoids on the reproductive function.

Association of increased S100A8 serum protein with early pregnancy loss

PROBLEM

The contribution of systemic S100A8 protein in menstrual cycle, pregnancy, and early pregnancy loss (EPL) is not known. Altered expression of S100A8 in maternal decidua is associated with recurrent early pregnancy loss. The objective of this study was to investigate the systemic level of S100A8 in different phases of menstrual cycle, different trimester of pregnancy, and in EPL.

METHOD OF STUDY

Level of S100A8 was investigated in serum samples of the subjects through enzyme-linked immunosorbent assay (ELISA).

RESULT AND CONCLUSION

S100A8 levels were elevated during proliferative phase of menstrual cycle. We found no statistical difference in S100A8 level in different trimester of pregnancy. S100A8 level was found to be significantly elevated in patients with EPL. This is the first study evaluating the systemic level of S100A8 predicting its role during menstrual cycle and pregnancy. It opens a new perspective in which S100A8 can be used as a prognostic marker for EPL.

Reduced levels of maternal progesterone during pregnancy increase the risk for allergic airway diseases in females only

Observational as well as experimental studies support that prenatal challenges seemed to be associated with an increased risk for allergic airway diseases in the offspring. However, insights into biomarkers involved in mediating this risk are largely elusive. We here aimed to test the association between endogenous and exogenous factors documented in pregnant women, including psychosocial, endocrine, and life style parameters, and the risk for allergic airway diseases in the children later in life. We further pursued to functionally test identified factors in a mouse model of an allergic airway response. In a prospectively designed pregnancy cohort (n = 409 families), women were recruited between the 4th and 12th week of pregnancy. To investigate an association between exposures during pregnancy and the incidence of allergic airway disease in children between 3 and 5 years of age, multiple logistic regression analyses were applied. Further, in prenatally stressed adult offspring of BALB/c-mated BALB/c female mice, asthma was experimentally induced by ovalbumin (OVA) sensitization. In addition to the prenatal stress challenge, some pregnant females were treated with the progesterone derivative dihydrodydrogesterone (DHD). In humans, we observed that high levels of maternal progesterone in early human pregnancies were associated with a decreased risk for an allergic airway disease (asthma or allergic rhinitis) in daughters (adjusted OR 0.92; 95% confidence interval [CI] 0.84 to 1.00) but not sons (aOR 1.02, 95% CI 0.94-1.10). In mice, prenatal DHD supplementation of stress-challenged dams attenuated prenatal stress-induced airway hyperresponsiveness exclusively in female offspring. Reduced levels of maternal progesterone during pregnancy-which can result from high stress perception-increase the risk for allergic airway diseases in females but not in males. Key messages: Lower maternal progesterone during pregnancy increases the risk for allergic airway disease only in female offspring. Prenatal progesterone supplementation ameliorates airway hyperreactivity in prenatally stressed murine offspring.

Regulation of the Anti-Inflammatory Cytokines Interleukin-4 and Interleukin-10 during Pregnancy

Inflammation mediated by both innate and adaptive immune cells is necessary for several important processes during pregnancy. Pro-inflammatory immune cell activation plays a critical role in embryo implantation, placentation, and parturition; however dysregulation of these cells can lead to detrimental pregnancy outcomes including spontaneous abortion, fetal growth restriction, maternal pathology including hypertensive disorders, or fetal and maternal death. The resolution of inflammation plays an important role throughout pregnancy and is largely mediated by immune cells that produce interleukin (IL)-4 and IL-10. The temporal and spatial aspects of reducing inflammation during pregnancy represent a complex process that if not functioning optimally can lead to persistent inflammation and pregnancy complications. In this review, we examine how immune cells that produce IL-4 and IL-10 are regulated throughout pregnancy as well as the effects that reduced IL-4 and IL-10 signaling has on fetal and maternal physiology.

The immune privilege of testis and gravid uterus: same difference?

The fetus in the gravid uterus and the developing spermatogenic cells in the adult testis both comprise special challenges for the host immune system. Protection of the neoantigens of the fetus and male germ cells from immune attack, defined as immune privilege, is fundamental for the propagation of species. Immune privilege is not simply the absence of leukocytes, but involves immune and non-immune cells acting synergistically together at multiple levels to create a unique tolerogenic environment. A number of the pathways are shared by the testis and gravid uterus. Amongst them steroid hormones, namely testosterone in the male and progesterone in the female, seem to function as key molecules that govern the local production of immunoregulatory factors which finally control the overall immune environment.

Neuroendocrinology of pregnancy and parturition

During pregnancy, the maternal brain drives a series of adaptive mechanisms that are fundamental for allowing fetal growth and development, protecting both mother and fetus from adverse programming and timing of parturition. This neuroendocrine concept is even more complex as fetal brain and placenta also participate as regulators of maternal-placental-fetal physiology. The placenta is now seen as a neuroendocrine organ, acting as a source of several neuroactive factors that may exert their biologic effects either locally or by entering maternal and fetal circulation, thus acting in an autocrine, paracrine, and endocrine manner. A variety of hypothalamic neurohormones (GnRH, GHRH, somatostatin, CRH, oxytocin) are expressed in the placenta. When stress occurs during pregnancy, the maternal, fetal, and placental hypothalamic-pituitary-adrenal (HPA) axes are activated to stimulate a series of responses contributing to maintain physiologic conditions while at the same time avoiding the adverse effects of stress on the mother and offspring. However, when stress is excessive, a number of obstetric complications may occur, such as preterm birth, pre-eclampsia and intrauterine growth restriction, related to an impairment of the placental adaptive response.

Estrogen-progesterone balance in the context of blastocyst implantation failure induced by predator stress

Diverse stressors can disrupt blastocyst implantation in inseminated female mammals. Stress-induced implantation failure can be mimicked by minute doses of exogenous estradiol, and some evidence indicates that it may be mitigated by exogenous progesterone. In Experiment 1, we showed that acute exposure to a rat across a wire-mesh grid caused elevation of corticosterone and progesterone. In Experiment 2, we showed that exposure of inseminated mice to rats across a grid during gestation days 1-5 was associated with avoidance of proximity to the grid and a significantly reduced number of implantation sites on gestation day 6. Rat-exposure also resulted in elevated progesterone levels in females that maintained their pregnancies, and elevated estradiol levels in females that lost their pregnancies. In Experiment 3, we investigated whether exogenous progesterone, estradiol, or a combination of both could influence implantation failure induced by rat-exposure stress. Treatment with 100 ng estradiol per day on gestation days 1-5 induced a complete absence of implantation sites on gestation day 6, regardless of the presence or absence of the stressor. Administration of 500 μg progesterone per day was insufficient to prevent the stress-induced pregnancy loss. However, 500 μg progesterone plus 10 ng estradiol per day did prevent implantation failure in rat-exposed females. These findings are consistent with the hypothesis that estradiol elevations contribute to stress-induced pregnancy loss, but show paradoxically that low doses of estradiol can act together with progesterone to mitigate stress-induced pregnancy loss.

Diet-induced obesity may affect the uterine immune environment in early-mid pregnancy, reducing NK-cell activity and potentially compromising uterine vascularization

OBJECTIVES

To investigate the effect of obesity in early-mid pregnancy on crucial pregnancy hormones and the uterine immune environment.

BACKGROUND

Obesity impacts reproductive ability, adversely affecting conception and leading to complications in pregnancy. Obesity is often regarded as a stress state and an immune disease, both of which may contribute to pregnancy failure. We previously demonstrated that stress in early pregnancy greatly alters progesterone secretion. As progesterone is an immunomodulator, altered progesterone secretion may adversely modify the maternal immune system. In the current study, we test the hypothesis that obesity during pregnancy adversely alters the uterine immune environment.

METHODS

An obese mouse model was created by feeding C57/BL6 mice on a high-fat (HF)/sugar diet for 12 weeks before pregnancy. Control mice were fed on lower-fat/sugar chow. Mice were mated, and on day 7.5 of pregnancy plasma progesterone and prolactin were measured by immunoassay. Cells from the uterus-draining inguinal lymph nodes were collected for analysis of the uterine immune response by flow cytometry.

RESULTS

Diet-induced obesity increased the secretion of progesterone and altered a number of uterine natural killer (NK)- and T-cell responses. These included a marked reduction in the percentage of leucocyte-derived NK cells and reduced expression of interferon-γ (IFN-γ) in the NK cells compared with control mice.

CONCLUSIONS

Maternal obesity, induced by an HF diet, may lead to a reduction in the expression of IFN-γ in NK cells. NK-cell-derived IFN-γ is reported to be involved in supporting uterine spiral artery remodelling. Thus, obesity in early pregnancy may compromise vascularization by reducing the expression of IFN-γ-positive NK cells. Furthermore, the expression of uterine CD8(+) cells was reduced in the HF diet-fed mice, suggesting obesity may adversely alter the maternal immune adaptation that is essential for effective pregnancy.

Macrophages regulate corpus luteum development during embryo implantation in mice

Macrophages are prominent in the uterus and ovary at conception. Here we utilize the Cd11b-Dtr mouse model of acute macrophage depletion to define the essential role of macrophages in early pregnancy. Macrophage depletion after conception caused embryo implantation arrest associated with diminished plasma progesterone and poor uterine receptivity. Implantation failure was alleviated by administration of bone marrow-derived CD11b+F4/80+ monocytes/macrophages. In the ovaries of macrophage-depleted mice, corpora lutea were profoundly abnormal, with elevated Ptgs2, Hif1a, and other inflammation and apoptosis genes and with diminished expression of steroidogenesis genes Star, Cyp11a1, and Hsd3b1. Infertility was rescued by exogenous progesterone, which confirmed that uterine refractoriness was fully attributable to the underlying luteal defect. In normally developing corpora lutea, macrophages were intimately juxtaposed with endothelial cells and expressed the proangiogenic marker TIE2. After macrophage depletion, substantial disruption of the luteal microvascular network occurred and was associated with altered ovarian expression of genes that encode vascular endothelial growth factors. These data indicate a critical role for macrophages in supporting the extensive vascular network required for corpus luteum integrity and production of progesterone essential for establishing pregnancy. Our findings raise the prospect that disruption of macrophage-endothelial cell interactions underpinning corpus luteum development contributes to infertility in women in whom luteal insufficiency is implicated.

Adaptive immune responses during pregnancy

It has long been believed that there is no immune interaction between mother and conceptus during pregnancy. This concept changed after evidence was provided that the maternal immune system is aware of the semiallogeneic conceptus and develops strategies to tolerate it. Since then, finely regulated mechanisms of active tolerance toward the fetus have been described. This Special Issue of the American Journal of Reproductive Immunology deals with these mechanisms. It begins with the description of minor histocompatibility antigens in the placenta; it further goes through adaptive immune responses toward paternal fetal antigens, mostly concentrating on regulatory T cells and molecules modulating the Th1/Th2 balance. The participation of antibody-producing B cells in normal and pathological pregnancies is also discussed. This introductory chapter resumes the concepts presented throughout the Issue and discusses the clinical applications raised from these concepts.

Behavioural, endocrine and immune responses to repeated social stress in pregnant gilts

Pregnant sows are exposed to various stressors in intensive pig husbandry that may have negative consequences on their health, reproductive performances and welfare. Social stress is one of these challenges, because gestating sows have to be housed in groups according to EU guidelines (2001/88/CE). The purpose of this study was to determine the consequences of repeated social stress in pregnant female pigs on their behavioural, endocrine and immunological responses and on pregnancy outcome. Pregnant gilts were submitted to a repeated social stress procedure induced by housing unfamiliar gilts in pairs changed twice a week between days 77 and 105 of gestation (S group, n = 18). Control gilts were housed in stable pairs during the same period (C group, n = 18). Agonistic behaviour was observed during the first 3 h after each grouping. Skin lesions were numbered 2 h after each grouping. Salivary cortisol was measured before and repeatedly during the 4 weeks of grouping. Gilts were immunized against keyhole limpet haemocyanin (KLH) on days 81 and 95 of gestation. Immunoglobulins G against KLH, proliferative responses to concanavalin A, lipopolysaccharide, pokeweed mitogen and KLH and peripheral blood leukocyte numbers were evaluated 1 week before the first grouping and 3 days after the last one. Agonistic interactions and skin lesions were observed in S gilts at each grouping, although there was a decline between the first and the last grouping (P < 0.05). The repeated social stress induced a sustained endocrine response as shown by elevated salivary cortisol levels from 1 to 48 h after grouping in S gilts compared to C gilts. The cellular as well as the humoral immunity and the leukocyte numbers were not influenced by social stress. Gestation length tended to be shorter in S gilts (P = 0.09), but litter size, piglet weight or mortality at birth were not affected. Variability of the response of S gilts to groupings was partly explained by their average success value determined according to the outcome (defeat or win) of all the groupings. In conclusion, our study demonstrates that the application of repeated social stress to pregnant gilts during the last third of their gestation repeatedly activates their hypothalamo-pituitary-adrenal axis but does not impair their immune function and pregnancy outcome.

Differential changes in the hypothalamic-pituitary-adrenal axis and prolactin responses to stress in early pregnant mice

Stress can cause pregnancy failure but it is unclear how the mother's neuroendocrine system responds to stress to impair mechanisms establishing implantation. We analysed stress-evoked hypothalamic-pituitary-adrenal (HPA) axis responses in early pregnant mice. HPA axis secretory responses to immune stress in early-mid pregnancy were strong and similar to that in virgins, although activation of hypothalamic vasopressin neurones, rather than corticotrophin-releasing hormone neurones, may be more important in the stress response in pregnancy. The site and mode of detrimental glucocorticoid action in pregnancy is not established. Because circulating prolactin is important for progesterone secretion and pregnancy establishment, we also hypothesised that stress negatively impacts on prolactin and its neuroendocrine control systems in early pregnant mice. Basal prolactin secretion was profoundly inhibited by either immune or fasting stress in early pregnancy. Prolactin release is inhibited by tonic dopamine release from tuberoinfundibular (TIDA) neurones. However, immune stress did not increase TIDA neurone activity in the median eminence in pregnant mice [measured by 3,4-dihydroxyphenylacetic acid (DOPAC) content and the DOPAC:dopamine ratio]. By contrast, both immune stress and fasting caused weak induction of Fos in TIDA neurones. However, Fos induction does not always reflect dopamine secretion. Taken together, the data suggest that the stress-evoked profound reduction in prolactin secretion does not involve substantially increased dopamine activity as anticipated. In pregnancy, there was also attenuated recruitment of parvocellular paraventricular nucleus neurones and increased activation of brainstem noradrenergic nuclei after immune stress, indicating that other mechanisms may be involved in the suppression of prolactin secretion. In summary, low prolactin and increased circulating glucocorticoids together may partly explain how a mother's endocrine system mediates stress-induced pregnancy failure.

Mother-offspring dialogue in early pregnancy: impact of adverse environment on pregnancy maintenance and neurobiology

The mother-offspring dialogue begins even before implantation and is essential to signal pregnancy, establish robust contact, and maintain embryo growth and development. Any circumstance that disrupts the dialogue risks pregnancy problems. A new look at how stress impacts on pregnancy involves its adverse effects on the key pregnancy hormones of progesterone and prolactin. These effects have far-reaching consequences on pregnancy maintenance, maternal anxiety and embryo programming. This review focuses on early pregnancy and how stress might compromise the multi-layer, two-way communication between mother and embryo.

Neuroendocrine control of maternal stress responses and fetal programming by stress in pregnancy

The major changes in highly dynamic neuroendocrine systems that are essential for establishing and maintaining pregnancy are outlined from studies on rodents. These changes optimise the internal environment to provide the life support system for the placenta, embryo and fetus. These include automatic prevention of further pregnancy, blood volume expansion, increased appetite and energy storage. The brain regulates these changes, in response to steroid (estrogens, progesterone) and peptide (lactogens, relaxin) hormone signals. Activation of inhibitory endogenous opioid mechanisms in the brain in late pregnancy restrains premature secretion of oxytocin, and attenuates hypothalamo-pituitary-adrenal (HPA) responses to stress. This opioid mechanism is activated by allopregnanolone, a neuroactive progesterone metabolite. The significance of reduced HPA axis responses in shifting maternal metabolic balance, and in protecting the fetuses from adverse programming of HPA axis stress responsiveness and anxious behaviour in later life is critically discussed. Experimental studies showing sex-dependent fetal programming by maternal stress or glucocorticoid exposure in late pregnancy are reviewed. The possibility of over-writing programming in offspring through neurosteroid administration is discussed. The impact of maternal stress on placental function is considered in the context of reconciling studies that show offspring programming by stress in very early or late pregnancy produce similar phenotypes in the offspring.

Endometrial expression of progesterone-induced blocking factor and galectins-1, -3, -9, and -3 binding protein in the luteal phase and early pregnancy in cattle

Progesterone-induced blocking factor (PIBF) and galectins modulate the maternal immune response during pregnancy. We hypothesized that the relative transcript abundance of the above genes would be different during the luteal phase/early pregnancy and would be affected by progesterone supplementation. To further test this, hypothesis protein expression analyses were carried out to evaluate the abundance and localization of LGALS9 and PIBF. Following estrus synchronization, heifers were inseminated ( n = 140) or not ( n = 70). Half the heifers in each status (cyclic or potentially pregnant) were randomly assigned to receive a progesterone-releasing intravaginal device (PRID) on day 3 after estrus, which elevated progesterone concentrations from day 3.5 to 8 ( P < 0.05), resulting in four treatment groups: cyclic and pregnant heifers, each with normal and high progesterone. After confirmation of pregnancy status in inseminated animals, uterine tissue was collected on days 5, 7, 13, or 16 of the luteal phase of the cycle/pregnancy. Gene and protein expression was determined using Q-RT-PCR and IHC, respectively, on 5 heifers per treatment per time point (i.e., 80 in total). Progesterone concentrations did not affect expression of any of the genes ( P > 0.05). LGALS9 and LGALS3BP were expressed at low levels in both cyclic and pregnant endometria until day 13. On day 16, expression increased only in the pregnant heifers ( P < 0.0001). LGALS1 and LGALS3 decreased on day 7 ( P < 0.0001) and remained low until day 16. Pregnancy had no effect on the expression of LGALS1, LGALS3, and PIBF. Additionally, LGALS9 and PIBF proteins were expressed in distinct uterine cell types. These results indicate that the galectins may be involved in uterine receptivity and/or implantation in heifers.

Progesterone induces a switch in oligosaccharyltransferase isoform expression: consequences on IgG N-glycosylation

The presence of additional N-glycans in the Fab region of IgG has shown to dramatically modify the properties and functionality of these molecules including changes in antibody affinity and stability. However, the underlying molecular mechanism responsible for the presence or absence of these glycans remains unknown. Polypeptide N-linked glycosylation is catalyzed in the lumen of the endoplasmic reticulum by the oligosaccharyltransferase complex. Mammalian cells can express two isoforms of the oligosaccharyltransferase catalytic subunit (STT3-A and STT3-B), which are endowed with distinct enzymatic properties. In this work we employed a murine hybridoma cell culture to study whether the expression of STT3 isoforms could be modulated by progesterone, thus altering the pattern of IgG N-glycosylation. We found that progesterone induces a switch of STT3 isoform expression, increasing IgG N-glycosylation. These effects were dependent on the progesterone-induced blocking factor (PIBF), whose concentration was modulated by progesterone. PIBF was previously found to be an immunomodulatory molecule relevant for the maintenance of pregnancy. We concluded that the STT3-B/STT3-A ratio modulates the N-glycosylation level of IgG, in agreement with previous data showing that full N-glycosylation of polypeptides requires cooperation between both catalytic isoforms. This work provides the first evidence that STT3 isoforms can be hormonally modulated, with marked consequences on IgG N-glycosylation.

Progestogens for treatment and prevention of pregnancy disorders

Progesterone appears to be the dominant hormone not only establishing a proper secretory endometrial development but also adequate decidualization to establish pregnancy and sustain pregnancy development. Progesterone is the natural immunoregulator to control the maternal immune system and not to reject the allogeneic fetus. There are two sources of progesterone: corpus luteum first and placenta later. Three progestogens can be used in pregnancy: (i) progesterone (per os, intravaginal and intramuscular), (ii) dydrogesterone (per os), and (iii) 17α-hydroxyprogesterone caproate (intramuscular). There are three indications, for which these progestogens can be clinically used either for treatment or prevention: (i) first trimester threatened and recurrent (habitual) abortion, (ii) premature labor/premature birth, and (iii) pre-eclampsia (hypertension in pregnancy). The available data are limited and only partially randomized. In threatened abortion the use of progesterone, dydrogesterone and 17α-hydroxyprogesterone caproate leads to a significant improved outcome, when at the time of threatened abortion a viable fetus has been ascertained by ultrasound. For prevention of recurrent abortion there are also some data indicating a significant effect compared with women without progestogen treatment. Prevention of preterm birth by progestogens (progesterone vaginally, orally and 17α-hydroxyprogesterone caproate intramuscularly) was significantly effective. The main study groups include pregnant women with a previous history of premature birth. However, also in women with shortened cervix use of progesterone seems to be helpful. The studies done so far in women with risk factors for pre-eclampsia or established pre-eclampsia were based on parenteral progesterone application. However, new studies are urgently needed.

Baby on board: do responses to stress in the maternal brain mediate adverse pregnancy outcome?

Stress and adverse environmental surroundings result in suboptimal conditions in a pregnant mother such that she may experience poor pregnancy outcome including complete pregnancy failure and preterm labor. Furthermore her developing baby is at risk of adverse programming, which confers susceptibility to long term ill health. While some mechanisms at the feto-maternal interface underlying these conditions are understood, the underlying cause for their adverse adaptation is often not clear. Progesterone plays a key role at many levels, including control of neuroendocrine responses to stress, procuring the required immune balance and controlling placental and decidual function, and lack of progesterone can explain many of the unwanted consequences of stress. How stress that is perceived by the mother inhibits progesterone secretion and action is beginning to be investigated. This overview of maternal neuroendocrine responses to stress throughout pregnancy analyses how they interact to compromise progesterone secretion and precipitate undesirable effects in mother and offspring.

PIBF: the double edged sword. Pregnancy and tumor

PROBLEM

The role of progesterone-dependent immunomodulation in the maintenance of normal pregnancy.

METHODS

In vitro and in vivo data on the effect that progesterone and its mediator progesterone-induced blocking factor (PIBF) exert on the immune functions of pregnant women are reviewed, together with clinical findings.

RESULTS

Activated pregnancy lymphocytes express progesterone receptors, which enable progesterone to induce a protein called PIBF. PIBF increases Th2 type cytokine production by signaling via a novel type of IL-4 receptor and activating the Jak/STAT pathway. PIBF inhibits phosholipase A2, thus reduces prostaglandin synthesis. PIBF inhibits perforin release in human decidual lymphocytes and reduces the deleterious effect of high NK activity on murine pregnancy. PIBF production is a characteristic feature of normal human pregnancy, and its concentration is reduced in threatened pregnancies. PIBF mRNA and protein are expressed in a variety of malignant tumors. Inhibition of PIBF synthesis increases survival rates of leukemic mice.

CONCLUSION

Progesterone-induced blocking factor is produced by pregnancy lymphocytes and also by malignant tumors. The PIBF-induced Th2-dominant immune response is favorable during pregnancy but might facilitate tumor growth by suppressing local antitumor immune responses.

Immune regulation of conception and embryo implantation-all about quality control?

Medawar's hypotheses for explaining maternal immune tolerance of the semi-allogeneic fetus are now proven incorrect or insufficient. The mother's immune response is not passive, suppressed, indolent or physically constrained in pregnancy. Instead, her immune system is centrally engaged with all steps of the reproductive process from conception to embryo implantation and placental development. Emerging studies show that immune cells are positioned and equipped to sense antigens and other signals originating in seminal fluid, the embryo and placental trophoblast. The immune response appears competent to utilise this information to discriminate the reproductive fitness and compatibility of the male partner and the integrity and developmental competence of the conceptus tissue. Since the immune response is modulated by the individual's infectious, inflammatory, stress, nutritional and metabolic status, immune influence on progression or disruption of pregnancy may be further influenced by environmental stressors and resource availability. This opinion paper advances the view that the immune system operates in pregnancy to integrate these signals and to exert executive quality control to either accommodate or reject the conceptus. It is argued that 'immune-mediated quality control' would facilitate optimal female reproductive investment and maximise offspring fitness, and thereby explain the evolutionary advantage of maternal immune awareness of the conceptus tissue.

Natural Killer cells: keepers of pregnancy in the turnstile of the environment

During early pregnancy, an orchestrated endocrine-immunological scenario of maternal adaptation toward tolerance of the semiallogeneic fetus is required. Mechanisms preventing fetal loss by protecting the immune privilege of the gravid uterus, i.e. Galectin-1 or regulatory T cells, have recently been identified. Further, the presence of a unique population of Natural Killer (NK) cells, in humans identified by their CD56(+++)Galectin (Gal)-1(+)CD16(-) phenotype in the uterine lining (decidua), has been proposed to be a pivotal aspect of maternal adaptation to pregnancy. Decidual NK (dNK) cells comprise the largest population of immune cells during the first trimester in human decidua and control trophoblast invasion and vascular remodeling through their ability to secrete an array of angiogenesis-regulating molecules, chemokines and cytokines. A wealth of environmental factors, such as smoking, altered nutrition, pollution or stress has been proposed to peril not only pregnancy, but also fetal development. Further, published evidence supports that NK cells act as sentinel cells and environmental challenges can change their phenotype, e.g. via epigenetic pathways. We here review the effect of environmental factors, largely stress perception, on NK cells and its implication for pregnancy, fetal development and general health. As NK cells may not only be passive responders to the environment, but can also be 'educated and licensed', we propose novel strategies aiming to take advantage of the versatility of NK cells in maintaining immunosurveillance and tissue homeostasis.

Stress in early pregnancy: maternal neuro-endocrine-immune responses and effects

Stress profoundly compromises reproduction, particularly when experienced in early gestation. One outcome is pregnancy failure: although glucocorticoids have adverse effects it is not clear what their role in pregnancy failure is. However, secretion of vital hormones such as progesterone and prolactin are reduced and this unbalances the delicate and important pregnancy-protective cytokine milieu. Complex interaction between glucocorticoids, progesterone/prolactin and the immune system evidently precipitate the loss, although early loss may confer reproductive advantage by preserving maternal energy stores and facilitating ongoing maternal care for other offspring. If pregnancy failure is not induced another, perhaps more profound, outcome of maternal stress is fetal programming. Much is known about the role of elevated glucocorticoids during late gestation in fetal programming, but in early gestation their role is less clear, though likely. Other key pregnancy hormones and immune factors also contribute to fetal programming. Undoubtedly integrated action of glucocorticoids, progesterone/prolactin and the immune system is crucial for optimal pregnancy outcome and is highly susceptible to environmental conditions.

Dydrogesterone in threatened miscarriage: a Malaysian experience

INTRODUCTION

Threatened miscarriage is a common problem during pregnancy.

METHODS

The aim of this prospective, open, randomised study was to determine whether dydrogesterone was more effective than conservative management alone in preventing miscarriage in women with vaginal bleeding up to week 16 of pregnancy. Women were excluded if they had a history of recurrent miscarriage. A total of 191 women were randomised to dydrogesterone (40 mg stat followed by 10mg twice daily) or conservative management (control group). The treatment was considered successful if the pregnancy continued beyond 20 weeks of gestation.

RESULTS

The success rate in the dydrogesterone group was statistically significantly higher than that in the control group (87.5% vs. 71.6%; p<0.05). Miscarriage occurred in 12.5% of women in the dydrogesterone group compared with 28.4% in the control group (p<0.05). There were no differences between the groups with regard to the incidence of Caesarean section, placenta praevia, antepartum haemorrhage, preterm labour (weeks 28-36), pregnancy-induced hypertension or low birth weight (<2500 g) babies. There were no intrauterine deaths or congenital abnormalities in either group.

CONCLUSION

Compared with conservative management, dydrogesterone had beneficial effects on maintaining pregnancy in women with threatened miscarriage.

Dydrogesterone support in threatened miscarriage

INTRODUCTION

The aim of this study was to determine whether dydrogesterone helps to preserve pregnancy in women with threatened miscarriage.

METHODS

146 women who presented with mild or moderate vaginal bleeding during the first trimester of pregnancy were randomised to receive oral dydrogesterone (10mg b.i.d.) (n=86) or no treatment (n=60). Dydrogesterone was continued until 1 week after the bleeding had stopped. All women received standard supportive care.

RESULTS

The incidence of miscarriage was significantly lower in the dydrogesterone group than in the untreated group (17.5% vs. 25%; p<0.05). There were no statistically significant differences between the groups with respect to pregnancy complications or congenital abnormalities.

CONCLUSION

Dydrogesterone appears to have beneficial effects in women with threatened miscarriage.

Progestational effects of dydrogesterone in vitro, in vivo and on the human endometrium

Dydrogesterone has a molecular structure closely related to that of natural progesterone, but it has enhanced oral availability compared with progesterone. The hormonal profile and the progestational potency of dydrogesterone has been determined in vitro, in vivo and in humans, in combination with estrogens or without. It showed varying affinity for progesterone-binding proteins in uterine tissue in vitro, depending on the species. It exerted a clear progestational response in the rabbit in vivo, although the potency was influenced somewhat by the route of administration. When used in hormone replacement therapy, 10mg dydrogesterone given sequentially provides adequate protection against endometrial hyperplasia in postmenopausal women using 2mg estradiol. Similarly, a dydrogesterone dose of 5mg also protects the endometrium when continuously combined with 1mg estradiol. Dydrogesterone also has beneficial effects in women with amenorrhea/oligomenorrhea, dysfunctional uterine bleeding and irregular cycles. In conclusion, having a similar profile to progesterone but with better oral availability, dydrogesterone has been used successfully to treat disorders related to absolute or relative progesterone deficiency.

Neuroendocrine circuitry and endometriosis: progesterone derivative dampens corticotropin-releasing hormone-induced inflammation by peritoneal cells in vitro

Clinical symptoms of endometriosis, such as pain and infertility, can be described as persistent stressors. Such continuous exposure to stress may severely affect the equilibrium and bidirectional communication of the endocrine and immune system, hereby further aggravating the progression of endometriosis. In the present study, we aimed to tease apart mediators that are involved in the stress response as well as in the progression of endometriosis. Women undergoing diagnostic laparoscopy due to infertility were recruited (n = 69). Within this cohort, early stage of endometriosis were diagnosed in n = 30 and advanced stage of endometriosis in n = 8. Levels of progesterone in serum were determined. Frequency of progesterone receptor (PR) expression on CD56(+) and CD8(+) peritoneal lymphocytes was analysed by flow cytometry. The production of tumour necrosis factor (TNF) and interleukin (IL)-10 by peritoneal leukocytes upon stimulation with the potent stress mediator corticotropin-releasing hormone (CRH) and the progesterone derivative dydrogesterone, or both, were evaluated. Furthermore, the production of progesterone-induced blocking factor (PIBF) by peritoneal leukocytes and the expression of PR in endometriotic tissue were investigated. Levels of progesterone in serum were decreased in women with endometriosis and inversely correlated to pain scores. Furthermore, an increased frequency of CD56(+)PR(+) and CD8(+)PR(+) peritoneal lymphocytes was present in advanced endometriosis. The TNF/IL-10 ratio, reflecting cytokine secretion by peritoneal cells, was higher in cells derived from endometriosis patients and could be further heightened by CRH stimulation, whereas stimulation with dydrogesterone abrogated the CRH-mediated inflammation. Finally, the expression of PIBF by peritoneal leukocytes was increased in endometriosis. Low levels of progesterone in the follicular phase could be responsible for the progression of endometriosis and related pain. Peripheral CRH, increasing upon high psychological stress, might contribute to the peritoneal inflammation present in endometriosis. The therapeutic application of progesterone derivatives, CRH blocking agents as well as improvement of stress coping may disrupt the vicious circle between the chronic peritoneal inflammation and high perception of psychological stress in endometriosis.

Oral dydrogesterone treatment during the first trimester of pregnancy: The prevention of miscarriage study (PROMIS). A double-blind, prospectively randomized, placebo-controlled, parallel group trial

OBJECTIVE

A planned study to test the hypothesis that dydrogesterone given during the first trimester of pregnancy can positively influence the immune system of women suffering from recurrent miscarriages and thereby lead to successful pregnancies. The primary objective is to show whether the administration of dydrogesterone during the first trimester of pregnancy increases the release of progesterone-induced blocking factor (PIBF) and causes a shift from Th-1 cytokines to Th-2 cytokines. Further objectives are an analysis of pregnancy outcome and to investigate the tolerability and safety of dydrogesterone use during pregnancy.

METHODS

A prospectively randomized, placebo-controlled study of 20 mg dydrogesterone per day during the first trimester of pregnancy in women aged between 18 and 38 and with a history of idiopathic recurrent miscarriage. Start of treatment will be after ovulation. The study will be conducted in a two-stage adaptive design, starting with a sample size of 20 patients per treatment group. The concentrations of Th-1 and Th-2 cytokines in the serum and PIBF in the urine will be measured. Efficacy will be measured primarily by the ratio IFNgamma/IL-10.

CONCLUSION

The results of this study will contribute to the discussion of a current concept of immunomodulation in pregnancy and potentially provide a treatment option for patients suffering from recurrent miscarriage.