New regulatory mechanisms for human extravillous trophoblast invasion

Mono-(2-ethylhexyl) phthalate induces trophoblast hypoxia and mitochondrial dysfunction through HIF-1α-miR-210-3p axis in HTR-8/SVneo cell line

The exposure to the ubiquitous phthalate metabolite mono-(2-ethylhexyl) phthalate (MEHP) is connected to dysregulated trophoblast function and placenta health; however, the underlying mechanisms preluding this scenario remain to be elucidated. In this study, we explored the hypoxemic effects of MEHP on a human placental first-trimester trophoblast cell line (HTR-8/Svneo). MEHP-treated trophoblast cells displayed significantly increased levels of oxidative stress and hypoxia-inducible factor-1 alpha (HIF-1α) attributed by the induction of hypoxia. Further, HIF-1α exhibited higher DNA binding activity and upregulated gene expression of its downstream target vascular endothelial growth factor A (VEGFA). The hypoxia-induced microRNA miR-210-3p was also significantly increased upon MEHP treatment followed by disrupted mitochondrial ATP generation and membrane potential. This was identified to possibly be facilitated by lowered mitochondrial DNA copy number and inhibited expression of electron transport chain subunits, such as mitochondrial complex-IV. These results suggest potential adverse effects of MEHP exposure in a trophoblast cell line mediated by HIF-1α and the epigenetic modulator miR-210-3p. Chronic placental hypoxia and oxidative stress have long been implicated in the pathogenesis of pregnancy complications such as preeclampsia. As we've revealed genetic and epigenetic factors underscoring a potential mechanism induced by MEHP, this brings to light another significant implication of phthalate exposure on maternal and fetal health.

Regulation and Function of Chemokines at the Maternal–Fetal Interface

Successful pregnancy requires the maternal immune system to tolerate the semi-allogeneic embryo. A good trophoblast function is also essential for successful embryo implantation and subsequent placental development. Chemokines are initially described in recruiting leukocytes. There are rich chemokines and chemokine receptor system at the maternal–fetal interface. Numerous studies have reported that they not only regulate trophoblast biological behaviors but also participate in the decidual immune response. At the same time, the chemokine system builds an important communication network between fetally derived trophoblast cells and maternally derived decidual cells. However, abnormal functions of chemokines or chemokine receptors are involved in a series of pregnancy complications. As growing evidence points to the roles of chemokines in pregnancy, there is a great need to summarize the available data on this topic. This review aimed to describe the recent research progress on the regulation and function of the main chemokines in pregnancy at the maternal–fetal interface. In addition, we also discussed the potential relationship between chemokines and pregnancy complications.

Increased levels of serum serglycin and agrin is associated with adverse perinatal outcome in early onset preeclampsia

Goal: Our aim was to determine whether alterations in serum serglycin and agrin levels in early-onset preeclampsia (EOPE) are useful in predicting adverse perinatal outcomes such as fetal growth restriction (FGR), intrauterine fetal demise (IUFD), preterm delivery and/or neonatal unit admission. Materials and Methods: A prospective case-controlled study enrolled 88 pregnant patients (44 EOPE and 44 controls). Maternal serum serglycin and agrin levels were determined before the 34th gestational week by enzyme-linked immunosorbent assay. Results: Compared with controls, women with EOPE had significantly higher serglycin and agrin levels (p = .018; p = .048). Multivariable logistic regression analysis revealed serglycin was independently associated with FGR in EOPE (OR 0.866; 95% CI 0.779-0.953). Agrin was independently associated with IUFD in EOPE (OR 0.757, 95% CI 0.636-0.879). Conclusions: The current study suggests that increased maternal serum serglycin is associated with FGR, and increased maternal serum agrin is associated with IUFD in EOPE.

Transcriptomic changes in the pre-implantation uterus highlight histotrophic nutrition of the developing marsupial embryo

Early pregnancy is a critical time for successful reproduction; up to half of human pregnancies fail before the development of the definitive chorioallantoic placenta. Unlike the situation in eutherian mammals, marsupial pregnancy is characterised by a long pre-implantation period prior to the development of the short-lived placenta, making them ideal models for study of the uterine environment promoting embryonic survival pre-implantation. Here we present a transcriptomic study of pre-implantation marsupial pregnancy, and identify differentially expressed genes in the Sminthopsis crassicaudata uterus involved in metabolism and biosynthesis, transport, immunity, tissue remodelling, and uterine receptivity. Interestingly, almost one quarter of the top 50 genes that are differentially upregulated in early pregnancy are putatively involved in histotrophy, highlighting the importance of nutrient transport to the conceptus prior to the development of the placenta. This work furthers our understanding of the mechanisms underlying survival of pre-implantation embryos in the earliest live bearing ancestors of mammals.

New discoveries on the biology and detection of human chorionic gonadotropin

Human chorionic gonadotropin (hCG) is a glycoprotein hormone comprising 2 subunits, alpha and beta joined non covalently. While similar in structure to luteinizing hormone (LH), hCG exists in multiple hormonal and non-endocrine agents, rather than as a single molecule like LH and the other glycoprotein hormones. These are regular hCG, hyperglycosylated hCG and the free beta-subunit of hyperglycosylated hCG. For 88 years regular hCG has been known as a promoter of corpus luteal progesterone production, even though this function only explains 3 weeks of a full gestations production of regular hCG. Research in recent years has explained the full gestational production by demonstration of critical functions in trophoblast differentiation and in fetal nutrition through myometrial spiral artery angiogenesis. While regular hCG is made by fused villous syncytiotrophoblast cells, extravillous invasive cytotrophoblast cells make the variant hyperglycosylated hCG. This variant is an autocrine factor, acting on extravillous invasive cytotrophoblast cells to initiate and control invasion as occurs at implantation of pregnancy and the establishment of hemochorial placentation, and malignancy as occurs in invasive hydatidiform mole and choriocarcinoma. Hyperglycosylated hCG inhibits apoptosis in extravillous invasive cytotrophoblast cells promoting cell invasion, growth and malignancy. Other non-trophoblastic malignancies retro-differentiate and produce a hyperglycosylated free beta-subunit of hCG (hCG free beta). This has been shown to be an autocrine factor antagonizing apoptosis furthering cancer cell growth and malignancy. New applications have been demonstrated for total hCG measurements and detection of the 3 hCG variants in pregnancy detection, monitoring pregnancy outcome, determining risk for Down syndrome fetus, predicting preeclampsia, detecting pituitary hCG, detecting and managing gestational trophoblastic diseases, diagnosing quiescent gestational trophoblastic disease, diagnosing placental site trophoblastic tumor, managing testicular germ cell malignancies, and monitoring other human malignancies. There are very few molecules with such wide and varying functions as regular hCG and its variants, and very few tests with such a wide spectrum of clinical applications as total hCG.

Integrin alpha5 is involved in fibronectin-induced human extravillous trophoblast invasion

To identify the molecules involved in human extravillous trophoblast (EVT) invasion, we raised murine mAbs that react with EVTs and obtained one mAb (CHL3) that inhibited invasion of a human choriocarcinoma-derived cell line, BeWo cells. The N-terminal 22 aminoacid sequence of the CHL3 antigen (150kDa) purified from placental tissue completely matched that of integrin alpha5, which is known to interact with fibronectin. Double immunohistochemical staining and flow cytometry confirmed the reactivity of CHL3 with integrin alpha5 and its expression on the surface of BeWo cells and human EVTs isolated from villous explant cultures. CHL3 mAb inhibited the attachment of human EVTs and BeWo cells to fibronectin-coated dishes, but not to Matrigel dishes. In the Matrigel invasion assay supplemented with or without fibronectin, the invasion of isolated EVTs and BeWo cells was attenuated by treatment with CHL3 without affecting cell proliferation. During invasion assays, the production of matrix metalloproteases 2 and 9 was not changed by CHL3. These findings suggest that interaction with fibronectin through integrin alpha5 plays an important role in human extravillous trophoblast invasion.

Intrauterine administration of autologous peripheral blood mononuclear cells promotes implantation rates in patients with repeated failure of IVF–embryo transfer

BACKGROUND

There are few effective approaches to infertile patients with repeated failure in IVF-embryo transfer therapy. Since recent evidence suggests that some populations of maternal immune cells positively support embryo implantation, we have developed a new approach using peripheral blood mononuclear cells (PBMCs).

METHODS

Patients who had not experienced successful pregnancy despite four or more IVF-embryo transfer sessions were enrolled in this study (n = 35, 35 cycles). PBMCs were obtained from patients on the day of oocyte retrieval and were cultured with HCG for 48 h. Two days later, PBMCs were freshly isolated from patients again, combined with cultured PBMC and then administered to the intrauterine cavity of the patients. Blastocyst transfer was performed on day 5, and the success of implantation in the PBMC-treated group was compared with that in the non-treated group.

RESULTS

Clinical pregnancy rate, implantation rate and live birth rate in the PBMC-treated group (41.2, 23.4 and 35.3%; n = 17, 47 and 16, respectively) were significantly higher than those in the non-treated group (11.1, 4.1 and 5.5%; n = 18, 49 and 18, respectively).

CONCLUSION

Intrauterine administration of autologous PBMC may be an effective approach to improve embryo implantation in patients with repeated IVF failures.