Embryo-maternal interactions at the implantation site: a delicate equilibrium

Subendometrial blood flow detected by Doppler ultrasound associates with pregnancy outcomes of frozen embryo transfer in patients with thin endometrium

PURPOSE

Multiple factors have been shown to influence the rate of clinical pregnancy after FET in IVF treatment, including embryo quality, synchronization of embryo and endometrium, and endometrial receptivity (ER). The subendometrial blood flow conditions could also contribute potentially major effects toward the establishment and maintenance of pregnancy. We conducted a retrospective cohort study to examine the correlation between subendometrial blood flow, as determined by Doppler ultrasound, and pregnancy outcomes in IVF patients with a thin endometrium (endometrium thickness [EMT] ≤ 0.7 cm).

METHODS

This was a retrospective cohort study conducted at a university-affiliated reproductive hospital from January 2017 to April 2023. The EMT and subendometrial blood flows were assessed using transvaginal color Doppler ultrasound and evaluated by experienced clinical ultrasound physicians on the endometrial transformation day. The pregnancy outcomes were followed up and documented in clinical medical records through the IVF cohort study at our center.

RESULTS

In the patients with 0.5 cm ≤ EMT ≤ 0.7 cm, the embryo implantation rate was statistically significant increased in the patients with the presence of subendometrial blood flow (OR 1.484; 95% CI, 1.001-2.200; P = 0.049; aOR 1.425; 95% CI, 1.030-2.123; P = 0.003). Patients with discernible subendometrial blood flow have superior live birth (P = 0.028), clinical pregnancy (P = 0.049), and embryo implantation (P = 0.027) compared to the patients without subendometrial blood flow when the EMT is ≤ 0.7 cm.

CONCLUSIONS

The presence of subendometrial blood flow detected by ultrasound was positively associated with successful embryo implantation and favorable pregnancy outcomes in patients with thin endometrium undergoing FET.

Predicting risk of endometrial failure: a biomarker signature that identifies a novel disruption independent of endometrial timing in patients undergoing hormonal replacement cycles

OBJECTIVE

To propose a new gene expression signature that identifies endometrial disruptions independent of endometrial luteal phase timing and predicts if patients are at risk of endometrial failure.

DESIGN

Multicentric, prospective study.

SETTING

Reproductive medicine research department in a public hospital affiliated with private fertility clinics and a reproductive genetics laboratory.

PATIENTS

Caucasian women (n = 281; 39.4 ± 4.8 years old with a body mass index of 22.9 ± 3.5 kg/m2) undergoing hormone replacement therapy between July 2018 and July 2021. Endometrial samples from 217 patients met RNA quality criteria for signature discovery and analysis.

INTERVENTION(S)

Endometrial biopsies collected in the mid-secretory phase.

MAIN OUTCOME MEASURE(S)

Endometrial luteal phase timing-corrected expression of 404 genes and reproductive outcomes of the first single embryo transfer (SET) after biopsy collection to identify prognostic biomarkers of endometrial failure.

RESULTS

Removal of endometrial timing variation from gene expression data allowed patients to be stratified into poor (n = 137) or good (n = 49) endometrial prognosis groups on the basis of their clinical and transcriptomic profiles. Significant differences were found between endometrial prognosis groups in terms of reproductive rates: pregnancy (44.6% vs. 79.6%), live birth (25.6% vs. 77.6%), clinical miscarriage (22.2% vs. 2.6%), and biochemical miscarriage (20.4% vs. 0%). The relative risk of endometrial failure for patients predicted as a poor endometrial prognosis was 3.3 times higher than those with a good prognosis. The differences in gene expression between both profiles were proposed as a biomarker, coined the endometrial failure risk (EFR) signature. Poor prognosis profiles were characterized by 59 upregulated and 63 downregulated genes mainly involved in regulation (17.0%), metabolism (8.4%), immune response, and inflammation (7.8%). This EFR signature had a median accuracy of 0.92 (min = 0.88, max = 0.94), median sensitivity of 0.96 (min = 0.91, max = 0.98), and median specificity of 0.84 (min = 0.77, max = 0.88), positioning itself as a promising biomarker for endometrial evaluation.

CONCLUSION(S)

The EFR signature revealed a novel endometrial disruption, independent of endometrial luteal phase timing, present in 73.7% of patients. This EFR signature stratified patients into 2 significantly distinct and clinically relevant prognosis profiles providing opportunities for personalized therapy. Nevertheless, further validations are needed before implementing this gene signature as an artificial intelligence (AI)-based tool to reduce the risk of patients experiencing endometrial failure.

A pilot study investigating a novel particle-based growth factor delivery system for preimplantation embryo culture

STUDY QUESTION

Can vascular endothelial growth factor (VEGF)-loaded silica supraparticles (V-SPs) be used as a novel mode of delivering VEGF to the developing preimplantation embryo in vitro?

SUMMARY ANSWER

Supplementation of embryo culture media with V-SPs promoted embryonic development in a manner equivalent to media supplemented with free VEGF.

WHAT IS KNOWN ALREADY

VEGF is a maternally derived growth factor that promotes preimplantation embryonic development in vitro. However, its use in clinical media has limitations due to its low stability in solution.

STUDY DESIGN, SIZE, DURATION

This study was a laboratory-based analysis utilising a mouse model. V-SPs were prepared in vitro and supplemented to embryonic culture media. The bioactivity of V-SPs was determined by analysis of blastocyst developmental outcomes (blastocyst development rate and total cell number).

PARTICIPANTS/MATERIALS, SETTING, METHODS

SPs were loaded with fluorescently labelled VEGF and release kinetics were characterised. Bioactivity of unlabelled VEGF released from V-SPs was determined by analysis of embryo developmental outcomes (blastocyst developmental rate and total cell number) following individual mouse embryo culture in 20 µl of G1/G2 media at 5% oxygen, supplemented with 10 ng/ml recombinant mouse VEGF in solution or with V-SPs. The bioactivity of freeze-dried V-SPs was also assessed to determine the efficacy of cryostorage.

MAIN RESULTS AND THE ROLE OF CHANCE

VEGF release kinetics were characterised by an initial burst of VEGF from loaded spheres followed by a consistent lower level of VEGF release over 48 h. VEGF released from V-SPs resulted in significant increases in total blastocyst cell number relative to the control (P < 0.001), replicating the effects of medium freely supplemented with fresh VEGF (P < 0.001). Similarly, freeze dried V-SPs exerted comparable effects on embryonic development (P < 0.05).

LARGE SCALE DATA

N/A.

LIMITATIONS, REASONS FOR CAUTION

In this proof of principle study, the effects of V-SPs on embryonic development were only analysed in a mouse model.

WIDER IMPLICATIONS OF THE FINDINGS

These findings suggest that SPs represent a novel method by which a targeted dose of therapeutic agents (e.g. bioactive VEGF) can be delivered to the developing in vitro embryo to promote embryonic development, an approach that negates the breakdown of VEGF associated with storage in solution. As such, V-SPs may be an alternative and effective method of delivering bioactive VEGF to the developing in vitro embryo; however, the potential use of V-SPs in clinical IVF requires further investigation.

STUDY FUNDING/COMPETING INTEREST(S)

This work was funded by the University of Melbourne. The authors have no conflict of interest to declare.

Role of the Macrophage Migration Inhibitory Factor in the Pathophysiology of Pre-Eclampsia

Proinflammatory cytokines are produced in pregnancy in response to the invading pathogens and/or nonmicrobial causes such as damage-associated molecules and embryonic semi-allogenic antigens. While inflammation is essential for a successful pregnancy, an excessive inflammatory response is implicated in several pathologies including pre-eclampsia (PE). This review focuses on the proinflammatory cytokine macrophage migration inhibitory factor (MIF), a critical regulator of the innate immune response and a major player of processes allowing normal placental development. PE is a severe pregnancy-related syndrome characterized by exaggerated inflammatory response and generalized endothelial damage. In some cases, usually of early onset, it originates from a maldevelopment of the placenta, and is associated with intrauterine growth restriction (IUGR) (placental PE). In other cases, usually of late onset, pre-pregnancy maternal diseases represent risk factors for the development of the disease (maternal PE). Available data suggest that low MIF production in early pregnancy could contribute to the abnormal placentation. The resulting placental hypoxia in later pregnancy could produce high release of MIF in maternal serum typical of placental PE. More studies are needed to understand the role of MIF, if any, in maternal PE.

Mitochondrial transformations in the aging human placenta

Mitochondria play a key role in homeostasis and are central to one of the leading hypotheses of aging, the free radical theory. Mitochondria function as a reticulated network, constantly adapting to the cellular environment through fusion (joining), biogenesis (formation of new mitochondria), and fission (separation). This adaptive response is particularly important in response to oxidative stress, cellular damage, and aging, when mitochondria are selectively removed through mitophagy, a mitochondrial equivalent of autophagy. During this complex process, mitochondria influence surrounding cell biology and organelles through the release of signaling molecules. Given that the human placenta is a unique organ having a transient and somewhat defined life span of ∼280 days, any adaption or dysfunction associated with mitochondrial physiology as a result of aging will have a dramatic impact on the health and function of both the placenta and the fetus. Additionally, a defective placenta during gestation, resulting in reduced fetal growth, has been shown to influence the development of chronic disease in later life. In this review we focus on the mitochondrial adaptions and transformations that accompany gestational length and share similarities with age-related diseases. In addition, we discuss the role of such changes in regulating placental function throughout gestation, the etiology of gestational complications, and the development of chronic diseases later in life.

Platelet-Rich plasma as an effective alternative approach for improving endometrial receptivity - a clinical retrospective study

Objective:

The aim of the present case series was to describe our experience with the use of PRP on patients with refractory thin endometria.

Methods:

This retrospective analysis included 24 IVF cycles in which patients presenting different infertility factors received intrauterine PRP infusion prior to embryo transfer. Outcomes of interest were: clinical and ongoing pregnancies, miscarriages, and births.

Results:

54% of the cycles in which PRP was employed resulted in ongoing gestation or birth; 12.5% of the cycles ended in miscarriages.

Conclusion:

Our data suggest that PRP improves intrauterine receptivity to embryo implantation, regardless of whether the endometrium reached the appropriate growth for embryo transfer.

Upregulation of Toll-like receptor 4 through anti-miR-Let-7a enhances blastocyst attachment to endometrial cells in mice

Despite encouraging advances in fertility technology, the success rate of an ongoing pregnancy is relatively low and predominantly associated with implantation failure. Inflammatory responses are beneficial in the fetomaternal interface and supposedly accelerate the chances for successful implantation. The current study aims to determine the effect of Toll-like receptor 4 (TLR4) overexpression in mouse blastocysts via Let-7a downregulation using intracytoplasmic sperm injection-sperm-mediated gene transfer on embryo attachment rate. The pLenti-III-GFP-miR-Off-Let-7a vector was transmitted to oocytes derived via in vitro maturation (IVM) and in vivo oocytes by using NaOH-treated spermatozoa. Let-7a and TLR4 expression levels were evaluated by quantitative real-time polymerase chain reaction (qRT-PCR), immunocytochemistry, and western blot analysis in both oocytes and embryos. Blastocyst adhesion on the endometrial cells was monitored by microscopic analysis. qRT-PCR results showed that Let-7a expression decreased in the IVM (GV-MII) oocytes compared to the in vivo oocyte (MII) group (p < .05). TLR4 showed a higher expression in GV-MII oocytes at both the gene and protein levels (p < .05). Following anti-miR-Let-7a transmission, the TLR4 expression level was significantly upregulated in embryos compared with the control groups (p < .05). Attachment and migration of trophoblasts cells towards endometrial cells dramatically increased compared to the control group (p < .05). Based on our results, we concluded that Let-7a might mediate embryo attachment through regulation of TLR4 expression levels.

Development of placental abnormalities in location and anatomy

Low‐lying placentas, placenta previa and abnormally invasive placentas are the most frequently occurring placental abnormalities in location and anatomy. These conditions can have serious consequences for mother and fetus mainly due to excessive blood loss before, during or after delivery. The incidence of such abnormalities is increasing, but treatment options and preventive strategies are limited. Therefore, it is crucial to understand the etiology of placental abnormalities in location and anatomy. Placental formation already starts at implantation and therefore disorders during implantation may cause these abnormalities. Understanding of the normal placental structure and development is essential to comprehend the etiology of placental abnormalities in location and anatomy, to diagnose the affected women and to guide future research for treatment and preventive strategies. We reviewed the literature on the structure and development of the normal placenta and the placental development resulting in low‐lying placentas, placenta previa and abnormally invasive placentas.

The Link Between Human Menstruation and Placental Delivery: A Novel Evolutionary Interpretation: Menstruation and fetal placental detachment share common evolved physiological processes dependent on progesterone withdrawal

A new interpretation of human menstruation is presented, resulting from a cross-disciplinary investigation of evolution, developmental biology, and physiology. A process evolutionarily associated with childbirth expresses itself as menstruation in women for whom frequent and continual failure to conceive has become the default situation. In humans and Old World primates, contractile uterine spiral arterioles evolved as the complement of the highly invasive hemochorionic placenta and is the selected phenotype. Placental progesterone withdrawal during the last stage of birth leads to arrested blood flow through maternal spiral arterioles, allowing detachment of the deciduous placenta with minimal maternal hemorrhage. In nonpregnant females, progesterone withdrawal from a degenerating corpus luteum initiates menstruation and stops blood flow through uterine spiral arterioles. Both events share similar physiological mechanisms and sequences. This explanation may improve our understanding of a recurrent event experienced by half of the human population and for a quarter of their adult reproductive life.

Platelet-rich plasma or blood-derived products to improve endometrial receptivity?

The use of platelet-rich plasma (PRP) to improve endometrial receptivity is gaining increasing attention in assisted reproduction technologies. The authors report that autologous PRP intrauterine administration improves pregnancy and birth rates, particularly in cases of patients presenting poor endometrial growth. Different groups of scientists proposed a similar approach years ago using whole blood-derived products also to improve endometrial receptivity. The important role played by cytokines and growth factors during embryo implantation has been well-known for a long time. These signaling molecules are present and released by blood cells during physiological, normal endometrial growth and implantation. Similar blood mediators are released from platelet granules upon a blood vessel injury. Methods described for PRP preparation for intrauterine administration are not precise, and they seem to be similar to those used to prepare peripheral blood-derived products. Thus, it is possible that when preparing PRP from whole blood, the final plasma product used as "PRP" contains platelets in addition to the important cytokines and growth factors released by the peripheral blood mononuclear cells present in the whole blood. Precise knowledge of the identity, concentration, and effects of the individual blood factors, their origin, whether platelets or blood mononuclear cells, will greatly contribute to improve and to make results obtained in fertility treatments more repeatable.

Endometrium receptivity in premature ovarian insufficiency - how to improve fertility rate and predict diseases?

More empathized approach is required and is obligatory to women with premature ovarian insufficiency (POI) interested for pregnancy. In order to improve fertility rate in POI patients our suggestions would be: (1) To decrease FSH value to 10-15 IU/L by increasing estrogen. Oocyte donation can be suggested after a minimum of six month interval from FSH between 10-15 IU/L and when no dominant follicles are found. (2) To perform oral glucose tolerance test (OGTT). Insulin sensitizing agents has to be included, when indicated, 3-6 month before pregnancy. (3) TSH has to be 1-2.5 mM/L during 3-6 months before pregnancy. (4) Tests for thrombophyllia (Leiden V, FII, MTHFR, PAI) have to be obligatory. They are less expensive than those repeated in vitro fertilizations. Therapy has to be included according to the indications. (5) In order to regulate disturbed immune response in POI patients with endometriosis oral contraceptive therapy is needed for atleast six months prior to the pregnancy. (5) Encourage the patients and advice them about healthy life style and eating habits. (6) Add other drugs, when they are indicated. Complex interplay between endocrine, immunological, haematological, and psychological factors are very often underdetected in POI patients. It is very important to find out the real time for oocyte donation after correcting all the disturbances, improving endometrium receptivity and reaching women's acceptable psychological status. Untreated disturbances induce cardiovascular diseases, diabetes mellitus, thyroid diseases, coagulopathioes etc.

Genome-wide DNA methylation patterns of bovine blastocysts derived from in vivo embryos subjected to in vitro culture before, during or after embryonic genome activation

Background

Aberrant DNA methylation patterns of genes required for development are common in in vitro produced embryos. In this regard, we previously identified altered DNA methylation patterns of in vivo developed blastocysts from embryos which spent different stages of development in vitro, indicating carryover effects of suboptimal culture conditions on epigenetic signatures of preimplantation embryos. However, epigenetic responses of in vivo originated embryos to suboptimal culture conditions are not fully understood. Therefore, here we investigated DNA methylation patterns of in vivo derived bovine embryos subjected to in vitro culture condition before, during or after major embryonic genome activation (EGA). For this, in vivo produced 2-, 8- and 16-cell stage embryos were cultured in vitro until the blastocyst stage and blastocysts were used for genome-wide DNA methylation analysis.

Results

The 2- and 8-cell flushed embryo groups showed lower blastocyst rates compared to the 16-cell flush group. This was further accompanied by increased numbers of differentially methylated genomic regions (DMRs) in blastocysts of the 2- and 8-cell flush groups compared to the complete in vivo control ones. Moreover, 1623 genomic loci including imprinted genes were hypermethylated in blastocyst of 2-, 8- and 16-cell flushed groups, indicating the presence of genomic regions which are sensitive to the in vitro culture at any stage of embryonic development. Furthermore, hypermethylated genomic loci outnumbered hypomethylated ones in blastocysts of 2- and 16-cell flushed embryo groups, but the opposite occurred in the 8-cell group. Moreover, DMRs which were unique to blastocysts of the 2-cell flushed group and inversely correlated with corresponding mRNA expression levels were involved in plasma membrane lactate transport, amino acid transport and phosphorus metabolic processes, whereas DMRs which were specific to the 8-cell group and inversely correlated with corresponding mRNA expression levels were involved in several biological processes including regulation of fatty acids and steroid biosynthesis processes.

Conclusion

In vivo embryos subjected to in vitro culture before and during major embryonic genome activation (EGA) are prone to changes in DNA methylation marks and exposure of in vivo embryos to in vitro culture during the time of EGA increased hypomethylated genomic loci in blastocysts.

Electronic supplementary material

The online version of this article (10.1186/s12864-018-4826-3) contains supplementary material, which is available to authorized users.

Steroids affect gene expression, ciliary activity, glucose uptake, progesterone receptor expression and immunoreactive steroidogenic protein expression in equine oviduct explants in vitro

The oviduct undergoes dramatic functional and morphological changes throughout the oestrous cycle of the mare. To unravel the effects of steroids on the morphology, functionality and gene expression of the equine oviduct, an in vitro oviduct explant culture system was stimulated with physiological concentrations of progesterone and 17β-oestradiol. Four conditions were compared: unsupplemented preovulatory explants, preovulatory explants that were stimulated with postovulatory hormone concentrations, unsupplemented postovulatory explants and postovulatory explants that were stimulated with preovulatory hormone concentrations. The modulating effects of both steroids on oviduct explants were investigated and the following parameters examined: (1) ciliary activity, (2) glucose consumption and lactate production pattern, (3) ultrastructure, (4) mRNA expression of embryotrophic genes, (5) steroidogenic capacities of oviductal explants and (6) progesterone receptor expression. The present paper shows that the equine oviduct is an organ with potential steroidogenic capacities, which is highly responsive to local changes in progesterone and 17β-oestradiol concentrations at the level of morphology, functionality and gene expression of the oviduct. These data provide a basis to study the importance of endocrine and paracrine signalling during early embryonic development in the horse.

PIM kinases 1, 2 and 3 in intracellular LIF signaling, proliferation and apoptosis in trophoblastic cells

Proviral insertion in murine (PIM) lymphoma proteins are mainly regulated by the Janus Kinase/Signal Transducer Activator of Transcription (JAK/STAT) signaling pathway, which can be activated by members of the Interleukin-6 (IL-6) family, including Leukemia Inhibitory Factor (LIF). Aim of the study was to compare PIM1, PIM2 and PIM3 expression and potential cellular functions in human first and third trimester trophoblast cells, the immortalized first trimester extravillous trophoblast cell line HTR8/SVneo and the choriocarcinoma cell line JEG-3. Expression was analyzed by qPCR and immunochemical staining. Functions were evaluated by PIM inhibition followed by analysis of kinetics of cell viability as assessed by MTS assay, proliferation by BrdU assay, and apoptosis by Western blotting for BAD, BCL-XL, (cleaved) PARP, CASP3 and c-MYC. Apoptosis and necrosis were tested by flow cytometry (annexin V/propidium iodide staining). All analyzed PIM kinases are expressed in primary trophoblast cells and both cell lines and are regulated upon stimulation with LIF. Inhibition of PIM kinases significantly reduces viability and proliferation and induces apoptosis. Simultaneously, phosphorylation of c-MYC was reduced. These results demonstrate the involvement of PIM kinases in LIF-induced regulation in different trophoblastic cell lines which may indicate similar functions in primary cells.

Elevated serum interleukin-1β levels and interleukin-1β-to-interleukin-1 receptor antagonist ratio 1 week after embryo transfer are associated with ectopic pregnancy

OBJECTIVE

To investigate whether interleukin-1β (IL-1β) and interleukin-1 receptor antagonist (IL-1RA) serum levels in the early luteal phase differ in IVF cycles that result in an ectopic pregnancy (EP) when compared with other outcomes.

DESIGN

Retrospective cohort.

SETTING

Not applicable.

PATIENT(S)

A total of 307 women whose serum samples were available, with the following IVF outcomes: 103 live births, 80 negative pregnancy tests, 52 biochemical pregnancies, 47 EPs, and 25 miscarriages.

INTERVENTION(S)

Serum samples were obtained on cycle days 24 and 28 (cycle day 14 = day of egg retrieval). Levels of IL-1β and IL-1RA were determined by quantitative ELISA performed by blinded personnel.

MAIN OUTCOME MEASURE(S)

IL-1β and IL-1RA levels, IL-1β-to-IL-1RA ratio versus cycle outcome.

RESULT(S)

The IL-1β levels were predictive of an EP. At cycle days 24 and 28 the mean IL-1β levels were higher in patients with an EP (127.1 pg/mL and 166.9 pg/mL, respectively) than in women with any other IVF outcome (15.8-55.3 pg/mL and 14.8-75.5 pg/mL, respectively). At cycle day 24 the IL-1β-to-IL-1RA ratio was 0.18 in the ectopic group versus 0.01-0.09 in the other groups.

CONCLUSION(S)

Elevated IL-1β levels and IL-1β-to-IL-1RA ratio as early as 4 days before the first pregnancy test are associated with an EP. If confirmed by prospective studies, clinical application of these findings could potentially improve EP detection.

Soluble ligands and their receptors in human embryo development and implantation

Extensive evidence suggests that soluble ligands and their receptors mediate human preimplantation embryo development and implantation. Progress in this complex area has been ongoing since the 1980s, with an ever-increasing list of candidates. This article specifically reviews evidence of soluble ligands and their receptors in the human preimplantation stage embryo and female reproductive tract. The focus will be on candidates produced by the human preimplantation embryo and those eliciting developmental responses in vitro, as well as endometrial factors related to implantation and receptivity. Pathways to clinical translation, including innovative diagnostics and other technologies, are also highlighted, drawing from this collective evidence toward facilitating joint improvements in embryo quality and endometrial receptivity. This strategy could not only benefit clinical outcomes in reproductive medicine but also provide broader insights into the peri-implantation period of human development to improve fetal and neonatal health.

PARP1 during embryo implantation and its upregulation by oestradiol in mice

Pregnancy requires successful implantation of an embryo, which occurs during a restricted period defined as ‘receptivity of the endometrium’ and is influenced by the ovarian steroids progesterone and oestradiol. The role of poly(ADP-ribose)polymerase-1 (PARP1) in apoptosis is well established. However, it is also involved in cell differentiation, proliferation and tissue remodelling. Previous studies have described the presence of PARP in the uterus, but its exact role in embryo implantation is not yet elucidated. Hence, in this study, we studied the expression of PARP1 in the uterus during embryo implantation and decidualisation, and its regulation by ovarian steroids. Our results show upregulation of the native form of PARP1 (∼116 kDa) in the cytosolic and nuclear compartments of implantation and non-implantation sites at day 5 (0500 h), followed by downregulation at day 5 (1000 h), during the embryo implantation period. The transcript level of Parp1 was also augmented during day 5 (0500 h). Inhibition of PARP1 activity by the drug EB-47 decreased the number of embryo implantation sites and blastocysts at day 5 (1000 h). Further, cleavage of native PARP1 was due to the activity of caspase-3 during the peri-implantation stage (day 5 (0500 h)), and is also required for embryo implantation, as inhibition of its activity compromised blastocyst implantation. The native (∼116 kDa) and cleaved (∼89 kDa) forms of PARP1 were both elevated during decidualisation of the uterus. Furthermore, the expression level of PARP1 in the uterus was found to be under the control of the hormone oestrogen. Our results clearly demonstrate that PARP1 participates in the process of embryo implantation.

Planning your every move: the role of β-actin and its post-transcriptional regulation in cell motility

Cell motility is a tightly regulated process that involves the polymerization of actin subunits. The formation of actin filaments is controlled through a variety of protein factors that accelerate or perturb the polymerization process. As is the case for most biological events, cell movement is also controlled at the level of gene expression. Growing research explains how the β-actin isoform of actin is particularly regulated through post-transcriptional events. This includes the discovery of multiple sites in the 3' untranslated region of β-actin mRNA to which RNA-binding proteins can associate. The control such proteins have on β-actin expression, and as a result, cell migration, continues to develop, and presents a thorough process that involves guiding an mRNA out of the nucleus, to a specific cytosolic destination, and then controlling the translation and decay of this message. In this review we will provide an overview on the recent progress regarding the mechanisms by which actin polymerization modulates cell movement and invasion and we will discuss the importance of post-transcriptional regulatory events in β-actin mediated effects on these processes.

Expression of P-cadherin (cadherin-3) and E-selectin in the villous trophoblast of first trimester human placenta

OBJECTIVE

Although trophoblastic invasion has a critical role in human placental development, very little is known about them. The aim of the present study was to localise the expression of P-cadherin (cadherin-3) and E-selectin in first trimester placenta.

MATERIAL AND METHODS

This study was conducted on 140 patients who had applied to Gülhane Military Medical Academy, Haydarpaşa Education Hospital, Department of Obstetrics and Gynaecology between 2005 and 2006. The patients were divided into three groups: ectopic pregnancy group (Group 1), spontaneous abortion group (group 2) and curettage group (group 3 and/or control group). Patients with a history of systemic diseases (such as thrombophilia), a disease or anatomical diagnosis that may cause recurrent abortion or an aetiological factor for ectopic pregnancy were excluded from the study. Paraffin blocks were stained with E-selectin and P-cadherin in accordance with the procedure. Demographic characteristics of patients (patient age, gravida, parity, number of previous abortions, and last menstrual period) and staining intensities were compared using Analysis of Variance (ANOVA) among groups.

RESULTS

According to the average scale score of P-cadherin staining of cells, the three groups were statistically different from each other (p=0.0001). This difference stems from statistically significantly lower scores in the spontaneous abortion group than in both the ectopic pregnancy group (p<0.001) and the control group (p<0.001). E-selectin immunostaining showed no positive staining in the groups.

CONCLUSION

In placental trophoblasts, decreased P-cadherin immunoreactivity plays a role in the aetiopathogenesis of spontaneous abortion.

The role of glycans in immune evasion: the human fetoembryonic defence system hypothesis revisited

Emerging data suggest that mechanisms to evade the human immune system may be shared by the conceptus, tumour cells, persistent pathogens and viruses. It is therefore timely to revisit the human fetoembryonic defense system (Hu-FEDS) hypothesis that was proposed in two papers in the 1990s. The initial paper suggested that glycoconjugates expressed in the human reproductive system inhibited immune responses directed against gametes and the developing human by employing their carbohydrate sequences as functional groups. These glycoconjugates were proposed to block specific binding interactions and interact with lectins linked to signal transduction pathways that modulated immune cell functions. The second article suggested that aggressive tumour cells and persistent pathogens (HIV, H. pylori, schistosomes) either mimicked or acquired the same carbohydrate functional groups employed in this system to evade immune responses. This subterfuge enabled these pathogens and tumour cells to couple their survival to the human reproductive imperative. The Hu-FEDS model has been repeatedly tested since its inception. Data relevant to this model have also been obtained in other studies. Herein, the Hu-FEDS hypothesis is revisited in the context of these more recent findings. Far more supportive evidence for this model now exists than when it was first proposed, and many of the original predictions have been validated. This type of subterfuge by pathogens and tumour cells likely applies to all sexually reproducing metazoans that must protect their gametes from immune responses. Intervention in these pathological states will likely remain problematic until this system of immune evasion is fully understood and appreciated.

Reversible effects of oxygen partial pressure on genes associated with placental angiogenesis and differentiation in primary-term cytotrophoblast cell culture

Timely regulated changes in oxygen partial pressure are important for placental formation. Disturbances could be responsible for pregnancy-related diseases like preeclampsia and intrauterine growth restriction. We aimed to (i) determine the effect of oxygen partial pressure on cytotrophoblast differentiation; (ii) measure mRNA expression and protein secretion from genes associated with placental angiogenesis; and (iii) determine the reversibility of these effects at different oxygen partial pressures. Term cytotrophoblasts were incubated at 21% and 2.5% O2 for 96 hr, or were switched between the two oxygen concentrations after 48 hr. Real-time PCR and enzyme-linked immunosorbent assays (ELISAs) were used to evaluate cell fusion and differentiation, measuring transcript levels for those genes involved in cell fusion and placental angiogenesis, including VEGF, PlGF, VEGFR1, sVEGFR1, sENG, INHA, and GCM1. Cytotrophoblasts underwent fusion and differentiation in 2.5% O2 . PlGF expression was inhibited while sVEGFR1 expression increased. VEGF and sENG mRNA expressions increased in 2.5% compared to 21% O2 , but no protein was detected in the cell supernatants. Finally, GCM1 mRNA expression increased during trophoblast differentiation at 21% O2 , but was inhibited at 2.5% O2 . These mRNA expression effects were reversed by returning the cells to 21% O2 . Thus, low-oxygen partial pressure does not inhibit term-cytotrophoblast cell fusion and differentiation in vitro. Lowering the oxygen partial pressure from 21% to 2.5% caused normal-term trophoblasts to reversibly modify their expression of genes associated with placental angiogenesis. This suggests that modifications observed in pregnancy diseases such as preeclampsia or growth retardation are probably due to an extrinsic effect on trophoblasts.

Immunobiology of trophoblast cells

Trophoblast cells contribute in all the stages of pregnancy starting from implantation of the embryo to parturition through their unique inherent properties of invasion, proliferation, differentiation and endocrine secretions. Hence, successful outcome of pregnancy depends greatly on the coordinated functioning of the trophoblast cells which is brouth about largely by the timely expression of integrins, adhesion molecules, cytokines, hormones and generation of nitric oxide. Loss of this coordination leads to adverse consequences like early pregnancy failures, preeclampsia, molar pregnancy and choriocarcinoma. In order to have better understanding of normal physiology of pregnancy and to assess the nature and causes of these pathological situations, in depth study of trophoblast function has been carried out by us and several other investigators.

Cryo-thawed embryo transfer: natural versus artificial cycle. A non-inferiority trial. (ANTARCTICA trial)

BACKGROUND

Frozen thawed embryo transfer (FET) is a cost-effective adjunct to IVF or IVF-ICSI treatment. In order to optimize treatment outcome, FET should be carried out during a period of optimal endometrial receptivity. To optimize implantation several methods for endometrium preparation have been proposed. In natural cycle FET (NC-FET), the endometrium develops under endogenous hormonal stimulation. The development of the dominant follicle and endometrium is monitored by ultrasound and FET is timed after triggering ovulation induction or determination of the spontaneous LH surge. In an artificial cycle FET (AC-FET) estrogens and progesterone are administered to prepare the endometrium for implantation. While the currently available data show no significant difference in pregnancy rates between these methods, well designed randomized controlled trials are lacking. Moreover there is little literature on difference in cancellation rates, cost-efficiency and adverse events.

METHODS AND DESIGN

In this randomized, multi-centre, non-inferiority trial we aim to test the hypothesis that there is no significant difference in live birth rates between patients undergoing NC-FET versus AC-FET. The primary outcome will be live birth rate per embryo transfer procedure. Secondary outcomes will be ongoing and clinical pregnancy rate, cancellation rate, (serious) adverse events and cost-efficiency. Based on a live birth rate of 20% and a minimal clinical important difference of 7.5% (one-sided alpha 2.5%, beta 20%) a total of 1150 patients will be needed. Analyzes will be performed using both per protocol as well as intention to treat analyses.

DISCUSSION

This prospective, randomized, non-inferiority trial aims to address the hypothesis that there is no significant difference in live birth rates between patients undergoing NC-FET versus patients undergoing AC-FET. Moreover it addresses cost-efficiency as well as the perceived burden of both treatments.

TRIAL REGISTER

Netherlands trial register (NTR): 1586.

Embryo-maternal communication: signalling before and during placentation in cattle and pig

Communication during early pregnancy is essential for successful reproduction. In this review we address the beginning of the communication between mother and developing embryo; including morphological and transcriptional changes in the endometrium as well as epigenetic regulation mechanisms directing the placentation. An increasing knowledge of the embryo-maternal communication might not only help to improve the fertility of our farm animals but also our understanding of human health and reproduction.

Protective Effects of Baicalin against Bromocriptine Induced Abortion in Mice

The Chinese herbal medicine Huang Qin (Radix Scutellariae) had been used for restless fetus for hundreds of years in China, however, little attention had been given to the components of the herb, specifically its ability to exert abortion-preventing effects at the maternal fatal interface. The present study was carried out to investigate the protective effects of baicalin and the possible mechanisms on pregnancies. Baicalin (at 10, 20, and 50 mg/kg BW respectively) was gavaged to bromocriptine-treated mice from gestation day (GD) 1 through GD 7. Abortion rates were calculated and the changes of interferon-γ (IFN-γ), interleukin-10 (IL-10) and progesterone were assayed on different gestation days. Results showed that the embryonic death rates were significantly decreased in groups supplemented with 20 or 50 mg/kg BW of baicalin, accompanied with reduced IFN-γ and enhanced progesterone contents. Moreover, the highest levels of IFN-γ appeared on GD 5 both in the control and in baicalin treated groups. It is concluded that baicalin can exert an anti-abortive effect by cutting down the production of IFN-γ and elevating the levels of progesterone in a dose dependent manner and IFN-γ is involved in an inflammatory reaction which is beneficial for a successful implantation.

The effects of human chorionic gonadotrophin, progesterone and oestradiol on trophoblast function

Remodelling of the uterine vasculature during the first trimester of human pregnancy requires invasion of trophoblast from the placenta into decidual spiral arterioles. The pregnancy-associated hormones human chorionic gonadotropin (hCG), progesterone (P(4)) and oestradiol (E(2)) are present at high concentrations at the maternal-fetal interface during the remodelling period and thus may contribute to the regulation of trophoblast movement. This study examined the effects of these hormones on trophoblast functions. HTR8/SVneo cells were treated with hCG (5-100mIU/mL), P(4) (20nM-20μM) or E(2) (0.07-734nM). hCG significantly stimulated migration and MMP-9 activity but did not affect cell numbers. P(4) significantly inhibited migration, MMP-2 and -9 activity and reduced cell numbers. E(2) had no effect on migration, MMP activity or cell numbers. We conclude that hCG and P(4), but not E(2), play direct roles in controlling trophoblast invasion, acting as positive and negative stimuli respectively to regulate trophoblast movement during vascular remodelling in early pregnancy.

Contraceptive vaccines targeting factors involved in establishment of pregnancy

Current methods of contraception lack specificity and are accompanied with serious side effects. A more specific method of contraception is needed. Contraceptive vaccines can provide most, if not all, the desired characteristics of an ideal contraceptive. This article reviews several factors involved in the establishment of pregnancy, focusing on those that are essential for successful implantation. Factors that are both essential and pregnancy-specific can provide potential targets for contraception. Using database search, 76 factors (cytokines/chemokines/growth factors/others) were identified that are involved in various steps of the establishment of pregnancy. Among these factors, three, namely chorionic gonadotropin (CG), leukemia inhibitory factor (LIF), and pre-implantation factor (PIF), are found to be unique and exciting molecules. Human CG is a well-known pregnancy-specific protein that has undergone phase I and phase II clinical trials, in women, as a contraceptive vaccine with encouraging results. LIF and PIF are pregnancy-specific and essential for successful implantation. These molecules are intriguing and may provide viable targets for immunocontraception. A multiepitope vaccine combining factors/antigens involved in various steps of the fertilization cascade and pregnancy establishment may provide a highly immunogenic and efficacious modality for contraception in humans.

Homozygosity at a class II MHC locus depresses female reproductive ability in European brown hares

The link between adaptive genetic variation, individual fitness and wildlife population dynamics is fundamental to the study of ecology and evolutionary biology. In this study, a Bayesian modelling approach was employed to examine whether individual variability at two major histocompatibility complex (MHC) class II loci (DQA and DRB) and eight neutral microsatellite loci explained variation in female reproductive success for wild populations of European brown hare (Lepus europaeus). We examined two aspects of reproduction: the ability to reproduce (sterility) and the number of offspring produced (fecundity). Samples were collected from eastern Austria, experiencing a sub-continental climatic regime, and from Belgium with a more Atlantic-influenced climate. As expected, reproductive success (both sterility and fecundity) was significantly influenced by age regardless of sampling locality. For Belgium, there was also a significant effect of DQA heterozygosity in determining whether females were able to reproduce (95% highest posterior density interval of the regression parameter [-3.64, -0.52]), but no corresponding effect was found for Austria. In neither region was reproduction significantly associated with heterozygosity at the DRB locus. DQA heterozygotes from both regions also showed a clear tendency, but not significantly so, to produce a larger number of offspring. Predictive simulations showed that, in Belgium, sub-populations of homozygotes will have higher rates of sterile individuals and lower average offspring numbers than heterozygotes. No similar effect is predicted for Austria. The mechanism for the spatial MHC effect is likely to be connected to mate choice for increased heterozygosity or to the linkage of certain MHC alleles with lethal recessives at other loci.

In vivo identification of regulators of cell invasion across basement membranes

Cell invasion through basement membranes during development, immune surveillance, and metastasis remains poorly understood. To gain further insight into this key cellular behavior, we performed an in vivo screen for regulators of cell invasion through basement membranes, using the simple model of Caenorhabditis elegans anchor cell invasion, and identified 99 genes that promote invasion, including the genes encoding the chaperonin complex cct. Notably, most of these genes have not been previously implicated in invasive cell behavior. We characterized members of the cct complex and 11 other gene products, determining the distinct aspects of the invasive cascade that they regulate, including formation of a specialized invasive cell membrane and its ability to breach the basement membrane. RNA interference-mediated knockdown of the human orthologs of cct-5 and lit-1, which had not previously been implicated in cell invasion, reduced the invasiveness of metastatic carcinoma cells, suggesting that a conserved genetic program underlies cell invasion. These results increase our understanding of the genetic underpinnings of cell invasion and also provide new potential therapeutic targets to limit this behavior.

Cancer models in Caenorhabditis elegans

Although now dogma, the idea that nonvertebrate organisms such as yeast, worms, and flies could inform, and in some cases even revolutionize, our understanding of oncogenesis in humans was not immediately obvious. Aided by the conservative nature of evolution and the persistence of a cohort of devoted researchers, the role of model organisms as a key tool in solving the cancer problem has, however, become widely accepted. In this review, we focus on the nematode Caenorhabditis elegans and its diverse and sometimes surprising contributions to our understanding of the tumorigenic process. Specifically, we discuss findings in the worm that address a well-defined set of processes known to be deregulated in cancer cells including cell cycle progression, growth factor signaling, terminal differentiation, apoptosis, the maintenance of genome stability, and developmental mechanisms relevant to invasion and metastasis.

Prostasin regulates human placental trophoblast cell proliferation via the epidermal growth factor receptor signaling pathway

BACKGROUND

Prostasin is a glycosylphosphatidylinositol-anchored extracellular serine protease with a role in epidermal growth factor receptor (EGFR) signal modulation. EGFR signaling has been shown to be important for regulating cytotrophoblast (CT) cell proliferation in human placenta. We investigated the impact of prostasin expression regulation on this cellular function as well as the molecular mechanisms involved in human cytotrophoblastic cells.

METHODS

An immortalized normal human CT cell line (B6Tert-1) was used as an in vitro cell model. Prostasin expression in B6Tert-1 cells was knocked down by transfection of a short interfering RNA. Lentivirus-mediated expression of recombinant human prostasin under tetracycline regulation was performed to obtain stable B6Tert-1 cell sublines that over-expressed prostasin. Changes in cell proliferation and EGFR signaling were evaluated by immunocytochemistry for Ki67 and western blot analysis, respectively, in B6Tert-1 cells with knocked-down or increased prostasin expression.

RESULTS

Prostasin knock-down in B6Tert-1 cells resulted in inhibition of cell proliferation, in association with down-regulated EGFR protein expression (both P < 0.05 versus control) as well as reduced phosphorylation of c-raf, mitogen-activated protein kinase (MAPK) kinases (MEK1/2) and extracellular signal-regulated kinases (Erk1/2) (all P < 0.05 versus control). Over-expression of prostasin led to up-regulation of the EGFR protein, but had no effect on cell proliferation or phosphorylation of MAPK signaling molecules in the B6Tert-1 cells.

CONCLUSIONS

Prostasin may regulate trophoblast cell proliferation via modulating the EGFR-MAPK signaling pathway.

Vitrification of human embryos subjected to blastomere biopsy for pre-implantation genetic screening produces higher survival and pregnancy rates than slow freezing

PURPOSE

Cryopreservation of blastocysts, especially those subjected to the trauma due to blastomere biopsy for the purposes of pre-implantation genetic screening (PGS), requires significant optimization. Laboratory and clinical outcomes were compared to determine the effect of two different cryopreservation techniques on the development of human pre-implantation embryos that underwent blastomere biopsy and blastocoel drainage prior to cryopreservation.

DESIGN

Retrospective clinical study.

PATIENT(S)

Women who requested cryotransfer of supernumerary blastocysts were analyzed by FISH.

RESULTS

The main outcome measures were post-thaw survival (SR), pregnancy (PR), and implantation (IR). The SR of slowly frozen blastocysts was 83% compared to 97% for vitrified blastocysts. In 160 cases where biopsied embryos were cryotransferred, the results for slowly frozen versus vitrified blastocysts were: SR (71% vs. 95%), PR (23% vs. 37%), and IR (26% vs. 36%, P < 0.05), respectively.

CONCLUSION

The results revealed that vitrified blastocysts provided higher SR, PR and IR as compared to slowly frozen counterparts.

Immunologic factors and reproductive success in women with primary repeated spontaneous abortion

In 109 women with primary RSA the presence of at least one live-born infant within 5 years of follow-up has been found positively associated with ACA intensity.

Characterization of endometrial growth in proliferative and early luteal phase in IVF cycles

Human endometrium has a definite role in implantation, although knowledge about its modifications in the course of IVF cycles is still limited. This study was performed to characterize endometrial growth throughout stimulation treatment in women undergoing IVF cycles, regardless of clinical outcomes. Endometrial growth was longitudinally evaluated by ultrasonography in the first induced ovarian stimulation cycle (717 patients). Acceleration and length of significant growth were used to assess the slope of the growth curve mathematically. Endometrial growth showed a parabolic trend and final thickness was significantly affected by age (P < 0.01). Endometria that tended to overgrowth had a more rapid and longer growth during the whole phase. A similar stimulation treatment was repeated within 6 months of the first one and a second evaluation was carried out to verify whether similar growth occurred. Similar growth was observed in 76% of the patients, with an absolute difference between the two cycles of <4 mm in 84% of cases. The endometrium seems to have an individual intrinsic potential that can be expressed regardless of the stimulation protocol. This supports the hypothesis that individual factors (intrinsic properties of the endometrium) significantly affect endometrial growth.

Expression and regulation of cholesterol sulfotransferase (SULT2B1b) in human endometrium

OBJECTIVE

To investigate the hormonal regulation of SULT2B1b in human endometrium.

DESIGN

In vitro study with human endometrial tissues and cultured human endometrial cells.

SETTING

University hospital.

PATIENT(S)

Thirty-seven women undergoing hysterectomy for benign disease.

INTERVENTION(S)

Human endometrial tissues were collected for in situ hybridization. Culture medium of human endometrial epithelial cells (EECs) was collected for determination of secretion of cholesterol sulfate (CS). Total RNAs were extracted from human endometrial tissues and cultured cells for real-time reverse transcriptase-polymerase chain reaction (RT-PCR).

MAIN OUTCOME MEASURE(S)

The expression of SULT2B1b mRNA in human endometrial tissues and cultured cells.

RESULT(S)

In situ hybridization studies and real-time RT-PCR showed that the amount of SULT2B1b mRNA in human endometrial tissues was significantly higher during the midluteal phase than during other phases of the menstrual cycle. The secretion of CS from EECs was confirmed using [(35)S]-phosphoadenosine phosphosulfate. The expression of SULT2B1b mRNA was induced by cAMP or P in human endometrial stromal cells (ESCs), whereas it was induced by cAMP or relaxin in EECs. The induction of SULT2B1b mRNA by P or relaxin was abolished by the specific protein kinase A (PKA) inhibitor, Rp-adenosine 3',5' cyclic monophosphothioate (Rp-cAMPS).

CONCLUSION(S)

The expression of SULT2B1b mRNA in ESCs is induced by P and that in EECs is induced by relaxin via the cAMP pathway.

The role of growth factors and cytokines during implantation: endocrine and paracrine interactions

Implantation, a critical step for establishing pregnancy, requires molecular and cellular events resulting in uterine growth and differentiation, blastocyst adhesion, invasion, and placental formation. Successful implantation requires a receptive endometrium, a normal and functional embryo at the blastocyst stage, and a synchronized dialogue between maternal and embryonic tissues. In addition to the well-characterized role of sex steroids, the complexity of embryo implantation and placentation is exemplified by the number of cytokines and growth factors with demonstrated roles in these processes. Disturbances in the normal expression and action of these cytokines result in an absolute or partial failure of implantation and abnormal placental formation in mice and human. Members of the gp130 cytokine family, interleukin-11 (IL-11) and leukemia inhibitory factor, the transforming growth factor beta superfamily, the colony-stimulating factors, and the IL-1 and IL-15 systems are crucial molecules for a successful implantation. Chemokines are also important, both in recruiting specific cohorts of leukocytes to the implantation site and in trophoblast trafficking and differentiation. This review provides discussion of the embryonic and uterine factors that are involved in the process of implantation in autocrine, paracrine, and/or juxtacrine manners at the hormonal, cellular, and molecular levels.

Effects of activin A on the in vitro development and mRNA expression of bovine embryos cultured in chemically-defined two-step culture medium

The purpose of the present study was to evaluate the effects of activin A on the developmental competence of in vitro fertilized (IVF) bovine embryos derived from a two-step defined culture system (C1/C2 medium) during the early or later stages of embryo development. To evaluate the effects of activin A on transcriptional levels, we analysed genes related to blastocyst hatching and implantation and to activin signalling pathway in IVF embryos. Cumulus-oocyte complexes were matured for 22 h and fertilized in vitro. Presumptive zygotes were cultured in the presence or absence of activin A during early (0-120 h, C1) or later (120-192 h, C2) stages. Although the developmental competence of embryos cultured with activin A in C1 medium was not significantly different from their corresponding controls, development to blastocysts (22.4% vs 34.7%; p < 0.05) and the blastocyst hatching rate (9.3% vs 22.4%; p < 0.05) in C2 medium supplemented with 100 ng/ml activin A were significantly higher than in the control group. To evaluate the effect of activin A on transcription, the relative expression levels of genes related to blastocyst hatching and implantation (Na/K-ATPase, E-cad and Glut-1) as well as activin signalling pathway (ActRII, ActRIIB and Smad2) were analysed. Compared to control medium, gene expression of Na/K-ATPase, E-cad, Glut-1, ActRII and ActRIIB was increased in medium supplemented with activin A. In conclusion, this study suggests that activin A, during the later stage of in vitro bovine embryo development, can enhance in vitro development of embryos by increasing hatching rates and affecting expression levels of genes related to hatching and implantation in defined culture medium.

Comparison of cell cycle regulatory gene mRNA in three different types of human trophoblasts and effect of transforming growth factor

AIM

Identifying the factors responsible for reducing the proliferation, syncytialization, and invasiveness of trophoblast tissues, as seen with preeclampsia, intrauterine growth restriction, and spontaneous miscarriage, is a current challenge in reproductive biology. These factors, transforming growth factor (TGF)-beta as an example, can work by altering trophoblast differentiation or proliferation. We therefore investigated and compared specific markers of trophoblast proliferation and differentiation in three commonly used trophoblast tissue cell models, and also investigated the influence of TGF-beta on these markers.

METHODS

In this study, we isolated human trophoblasts from first trimester and term placentas, and additionally used human choriocarcinoma cells (JEG-3). Baseline values of human chorionic gonadotropin (hCG) secretion and relative mRNA levels of cell cycle regulators (cyclin E, p21, p27, and p57) were investigated for each cell type. We also investigated the influence of TGF-beta on these parameters.

RESULTS

Quantitative and longitudinal production of hCG differed between the three cell types. Significantly different amounts of cyclin E, p21, p27, and p57 mRNA were demonstrated within each cell type, as well as between all the cell types, throughout the culture time period. Each trophoblast type demonstrated a reduction of hCG secretion in response to TGF-beta. TGF-beta did not show a consistent effect on the cell cycle mRNA of any of the cell types.

CONCLUSION

We were able to characterize and compare the differential production of hCG, as well as the differential expression of cell cycle-associated mRNA of early trophoblasts, term trophoblasts, and choriocarcinoma cells. The production of hCG was altered by TGF-beta, although mRNA levels were not markedly altered by TGF-beta.

Interferons and the maternal-conceptus dialog in mammals

Two-way communication between the conceptus and the mother during early pregnancy is essential if the pregnancy is to survive. In this review, our primary focus is on biochemical communication between the conceptus and mother in the ruminant ungulate species. We emphasize, in particular, the role played by interferon-tau (IFNT) in triggering maternal responses in cattle and sheep and how maternal factors intervene to up-regulate IFNT gene (IFNT) expression in trophoblast. However, we also consider the possibility that different signaling cytokines or the physical presence of trophoblast may induce a partial IFN response in endometrium of those species where there is no evidence for large scale trophoblast IFN production. Conceivably, disparate signaling mechanisms trigger common downstream events necessary to secure a successful pregnancy.

Culture of mature trophoblastic giant cells from bovine placentomes

The mostly binucleate trophoblast giant cells (TGC) found in bovine placentomes, in addition to synthesizing and releasing hormones play an important role in fetal development and maternal adaptation to pregnancy. Placentomes from early gestation were collected, and for isolation of mature TGC, three cellular disaggregation methods, mechanical (MECH), enzymatic by trypsin (TRYP) or collagenase (COLL) were compared to each other. Further on, the cell survival in culture medium (DMEM) supplemented with either 10% fetal calf serum (FCS) or 10% serum replacement (SR) on culture plates free of any substrate was evaluated over a period of 90 days by trypan blue exclusion. The cells were further characterized by HOECHST 33342 nuclear staining, and immunocytochemical staining with monoclonal antibodies against vimentin and cytokeratin. A mean total rate of TGC survival of 82.56% was recorded. Statistical analysis showed significantly higher survival rates after enzymatic disaggregation with COLL (86.23%) than following MECH (80.38%) or TRYP (80.91%) treatment. Supplementation of DMEM with FCS resulted in significantly higher cellular survival rates (87.13%) when compared to the addition of SR (77.73%). Analysis of the influence of both, disaggregation method and medium supplementation on TGC survival revealed statistically significant differences between the following groups: MECH-SR (71.09%) was significantly lower than all other groups; TRYP-SR (78.03%) was significantly different from all other groups; TRYP-FCS (83.43%) and COLL-SR (84.08%) were significantly lower than MECH-FCS (89.98%) which together with COLL-FCS (88.25%) showed the highest cellular survival rate. In summary, our results show that TGC isolated from early gestation placentomes may be viable for more than 90 days of culture. However, whether these TGC produce placental lactogen throughout this period has yet to be determined.

Assessment of changes in endometrial and subendometrial volume and vascularity during the normal menstrual cycle using three-dimensional power Doppler ultrasound

OBJECTIVES

To describe changes in endometrial and subendometrial volume and vascularity during the normal menstrual cycle using three-dimensional (3D) power Doppler ultrasonography.

METHODS

Fourteen healthy volunteers, 24-44 years old with regular menstrual cycles, underwent serial transvaginal 3D power Doppler ultrasound examinations of the uterus on cycle day 2, 3 or 4, then daily from cycle day 9 until follicular rupture and 1, 2, 5, 7 and 12 days after follicular rupture. Endometrial and subendometrial volume (cm3), vascularization index (VI), flow index (FI) and vascularization flow index (VFI) were calculated using the VOCAL (Virtual Organ Computer-aided AnaLysis) software.

RESULTS

Endometrial and subendometrial vascularity indices increased throughout the follicular phase, decreased to a nadir 2 days after follicular rupture and then increased again during the luteal phase. Endometrial and subendometrial volume increased rapidly during the follicular phase and then remained almost unchanged during the luteal phase.

CONCLUSIONS

Substantial changes occur in endometrial volume and vascularization during the normal menstrual cycle. There is the potential for 3D power Doppler ultrasonography to become a useful tool for assessing pathological changes associated with female subfertility and abnormal uterine bleeding.

Does addition of low-dose aspirin and/or steroid as a standard treatment in nonselected intracytoplasmic sperm injection cycles improve in vitro fertilization success? A randomized, prospective, placebo-controlled study

PURPOSE

To investigate the effects of short-term low-dose aspirin and/or steroid use on implantation and pregnancy rates in nonselected intracytoplasmic sperm injection (ICSI) cycles.

METHODS

Two-hundred patients undergoing ICSI for their first cycle were enrolled in this study. Participants were then randomized into four groups on the embryo transfer day. Aspirin (100 mg/day) in group A, prednisolone (10 mg/day) in group B, aspirin along with prednisolone in group C were given while placebo was administrated to group D.

RESULT

There were no statistically significant differences recorded in the demographic, ovulation induction cycle characteristics between groups. Mean transferred embryo number and mean top quality embryo number were similar among study groups. There were no statistical differences in implantation and pregnancy rates between study groups.

CONCLUSION

Administration of low-dose aspirin and prednisolone alone or concomitant as a standard treatment have no positive effects on implantation and/or pregnancy rates.

Immunohistochemical localization of beta1 and beta4 integrins in mouse endometrium during implantation and early pregnancy

Implantation presents the remarkable synchronisation between the development of embryo and differentiation of endometrium. Cell-cell adhesion is an important phenomenon taking place during blastocyst implantation in uterine membrane. We think that the investigation of existence and the level of integrins in women can be a guide for treatment of infertility. Our purpose in this study was to show expression beta1 and beta4 integrins on gestational days 4, 6, 12 by immunohistochemical methods and to investigate whether beta4 integrin is a useful marker for receptivity. beta1 and beta4 integrin were exhibited on surface epithelium on gestational day 4. On the other hand, strong beta4 immunoreactivity was detected on surface epithelium and glandular cells on gestational day 12 but no beta1 reactivity was present in the surface epithelium and glandular cells on day 12. In conclusion, both beta1 and beta4 integrins may have a role in implantation process because positive immunoreactivity was seen on apical membrane of surface epithelium on day 4 when implantation occurred. The localization to apical pole of surface epithelium suggest a role for beta1, beta4 integrins in initial embryo and endometrium interaction. It does not seem that beta1 integrin has a role supporting pregnancy since expression of beta4 on surface epithelium and glandular epithelium disappeared on day 12. beta4 integrin expression increasing on day 12 of pregnancy leads us to think a possible functional role supporting pregnancy.

Feto-maternal biology and ethics of human society

The growing interest in human reproduction and the identity of the embryo have prompted us to bring some considerations to the attention of scientists. In particular, we focus on the interactive relationship between the embryo and the mother starting from the earliest stages of development. Principles governing the acceptance and growth of the embryo in the uterus may represent a model for mutual tolerance and peaceful co-existence in human society.