Impairment of the accumulation of decidual T cells, NK cells, and monocytes, and the poor vascular remodeling of spiral arteries, were observed in oocyte donation cases, regardless of the presence or absence of preeclampsia

Spatial Activation of Autophagy in Human Placenta-Related Tissue During Labor: A Possible Mechanism for Labor Onset

INTRODUCTION

To explore the mechanisms of labor by investigating the autophagy of placental and fetal membranes tissue in normal pregnant women.

METHODS

Placenta and fetal membranes were collected from women with singleton pregnancies without any medical complications and from women who delivered vaginally (labor-initiated group; L group) or by caesarean section (labor-noninitiated group; NL group). Autophagosomes were observed by transmission electron microscopy (TEM). Immunofluorescence and western blotting (WB) were used to detect protein levels of the autophagy markers LC3A and LC3B. TEM, immunohistochemistry (IHC), and WB were used to compare autophagy in different parts of the placenta and fetal membranes in the L and NL groups. The expression of LC3B/LC3A, ROCK1, and ROCK2 in the placenta of nonpregnant and pregnant rats was detected by WB and IHC.

RESULTS

TEM and IHC results showed an increase in the number of autophagosomes and autophagic lysosomes in the L group, and WB results indicated an increase in the LC3B/A ratio between the placenta and fetal membranes in the L group. Autophagy was significantly increased on the maternal side of the placenta in the L group, and the level of autophagy became higher near rupture in the fetal membranes and near the point where the umbilical cord joins the placenta in the L group. The LC3B/A ratio increased and ROCK1 and ROCK2 levels decreased in postnatal rats.

DISCUSSION

Autophagy can occur in the placenta and fetal membranes and its activity is higher at the onset of labor, suggesting a role in labor.

Autophagy genes and signaling pathways in endometrial decidualization and pregnancy complications

Autophagy is a process that occurs in almost all eukaryotic cells and this process is controlled by several molecular processes. Its biological roles include the provision of energy, the maintenance of cell homeostasis, and the promotion of aberrant cell death. The importance of autophagy in pregnancy is gradually becoming recognized. In literature, it has been indicated that autophagy has three different effects on the onset and maintenance of pregnancy: embryo (embryonic development), feto-maternal immune crosstalk, and maternal (decidualization). In humans, proper decidualization is a major predictor of pregnancy accomplishment and it can be influenced by different factors. This review highlights the genes, pathways, regulation, and function of autophagy in endometrial decidualization and other involved factors in this process.

Unraveling the molecular mechanisms driving enhanced invasion capability of extravillous trophoblast cells: a comprehensive review

Precise extravillous trophoblast (EVT) invasion is crucial for successful placentation and pregnancy. This review focuses on elucidating the mechanisms that promote heightened EVT invasion. We comprehensively summarize the pivotal roles of hormones, angiogenesis, hypoxia, stress, the extracellular matrix microenvironment, epithelial-to-mesenchymal transition (EMT), immunity, inflammation, programmed cell death, epigenetic modifications, and microbiota in facilitating EVT invasion. The molecular mechanisms underlying enhanced EVT invasion may provide valuable insights into potential pathogenic mechanisms associated with diseases characterized by excessive invasion, such as the placenta accreta spectrum (PAS), thereby offering novel perspectives for managing pregnancy complications related to deficient EVT invasion.

Pregnancies through oocyte donation. A mini review of pathways involved in placental dysfunction

Pregnancies resulting from assisted reproductive techniques (ART) are increasingly prevalent worldwide. While most pregnancies conceived through in-vitro fertilization (IVF) progress without complications, mounting evidence suggests that these pregnancies are at a heightened risk of adverse perinatal outcomes. Specifically, IVF pregnancies involving oocyte donation have garnered attention due to numerous reports indicating an elevated risk profile for pregnancy-related complications within this subgroup of patients. The precise mechanisms contributing to this increased risk of complications remain incompletely understood. Nonetheless, it is likely that they are mediated by an abnormal immune response at the fetal-maternal interface. Additionally, these outcomes may be influenced by baseline patient characteristics, such as the etiology of infertility, absence of corpus luteum, and variations in endometrial preparation protocols, among other factors. This review aims to succinctly summarize the most widely accepted mechanisms that potentially contribute to the onset of placental dysfunction in pregnancies conceived through oocyte donation.

Excessive Immune Activation and the Correlation with Decreased Expression of PD-1 at the Maternal-Fetal Interface in Preeclampsia

The etiology of preeclampsia (PE) is still unknown, and excessive immune activation is an important component of its pathogenesis. Programmed cell death protein 1 (PD-1) is one of immune checkpoints which may prevent overactivated immune attack and lead to a tolerant immune microenvironment. Little is known about the involvement of PD-1-mediated immunoregulation at the maternal-fetal interface in PE. To investigate the inflammatory pattern and the involvement of PD-1 in the decidua of women with PE, decidual tissues were obtained from PE and control pregnant women. Quantitative RT-PCR analysis of the mRNA levels of the inflammatory cytokines was performed. PD-1 expression was detected by immunohistochemistry, western blot analysis, and flow cytometry. To prove the role of PD-1, decidual immune cells were incubated with blocking antibodies, and the inflammatory cytokines were detected by ELISA. We observed that the mRNA levels of IL-1β, IL-6, TNF-α, and IFN-γ were higher in the decidua of the PE group than in the decidua of the control group. The mRNA levels of IL-4 and IL-10 were lower in PE. The expression level of PD-1 was significantly downregulated, and the proportion (%) of PD-1 + CD45 + cells was significantly lower in PE. There was a significant linear correlation between PD-1 expression and common proinflammatory cytokines in the decidua. Anti-PD-1 blocking antibody significantly increased the secretion of proinflammatory cytokines. Our data suggested that the inflammatory pattern and decreased PD-1 expression in the decidua might play an active role in the local immunoregulatory mechanisms of PE. The PD-1 pathway in the maternal-fetal interface possibly function to break the tolerant immune microenvironment in PE via inflammatory cytokines.

Impaired autophagy with augmented apoptosis in a Th1/Th2-imbalanced placental micromilieu is associated with spontaneous preterm birth

Background: Despite decades of research, the pathogenesis of spontaneous preterm birth (PTB) remains largely unknown. Limited currently available data on PTB pathogenesis are based on rodent models, which do not accurately reflect the complexity of the human placenta across gestation. While much study has focused on placental infection and inflammation associated with PTB, two key potentially important cellular events in the placenta-apoptosis and autophagy-remained less explored. Understanding the role of these processes in the human placenta may unravel currently ill-understood processes in the pathomechanism of PTB. Methods: To address this necessity, we conducted qRT-PCR and ELISA assays on placental villous tissue from 20 spontaneous preterm and 20 term deliveries, to assess the inter-relationships between inflammation, apoptosis, and autophagy in villous tissue in order to clarify their roles in the pathogenesis of PTB. Results: We found disrupted balance between pro-apoptotic BAX and anti-apoptotic BCL2 gene/protein expression in preterm placenta, which was associated with significant reduction of BCL2 and increase of BAX proteins along with upregulation of active CASP3 and CASP8 suggesting augmented apoptosis in PTB. In addition, we detected impaired autophagy in the same samples, evidenced by significant accumulation of autophagosome cargo protein p62/SQSTM1 in the preterm villous placentas, which was associated with simultaneous downregulation of an essential autophagy gene ATG7 and upregulation of Ca2+-activated cysteine protease CAPN1. Placental aggregation of p62 was inversely correlated with newborn birth weight, suggesting a potential link between placental autophagy impairment and fetal development. These two aberrations were detected in a micromilieu where the genes of the Th2 cytokines IL10 and IL13 were downregulated, suggesting an alteration in the Th1/Th2 immune balance in the preterm placenta. Conclusion: Taken together, our observations suggest that impaired autophagy and augmented apoptosis in a Th1/Th2 imbalanced placental micro-environment may be associated with the pathogenesis of spontaneous PTB.

Progress in the understanding of the pathophysiology of immunologic maladaptation related to early-onset preeclampsia and metabolic syndrome related to late-onset preeclampsia

Among mammalian species, human reproduction has 2 outstanding features. The human hemochorial placentation is characterized by a very deep endovascular trophoblast invasion in the spiral arteries, reaching deep into the myometrium. This requires an agonistic direct cell-cell interaction between the maternal immune system and semiallogeneic trophoblast. The second feature is preeclampsia, a heterogeneous syndrome, a uniquely human condition. The human female is one of the few mammals exposed to her partner's semen on multiple occasions before conception. Regulatory T cells, especially paternal antigen-specific regulatory T cells, play an important role in the maintenance of pregnancy. Sexual intercourse increases the number of dendritic cells in the uterus that play an important role in the induction of paternal antigen-specific regulatory T cells. Paternal antigen-specific regulatory T cells maintain pregnancy by inducing tolerance. In the decidua basalis of preeclamptic cases, clonal regulatory T cells are reduced; these would normally monoclonally expand to recognize fetal or paternal antigens. Programmed cell death-1 expressed on T cells regulate cytotoxic T-cell activity and protect the fetus against maternal rejection. Programmed cell death-1 expression on clonal cytotoxic T cells is reduced in preeclampsia especially in early-onset preeclampsia, making the fetus and placenta vulnerable to attack by cytotoxic T cells. These phenomena can explain the epidemiologic phenomenon that preeclampsia is more common in couples using condom contraception, with shorter cohabitation periods, first pregnancies, first pregnancies in multiparous women when they change partner, and pregnancies after assisted reproduction using donated gametes. In contrast to its importance in early-onset preeclampsia, shallow trophoblast invasion does not play a role in the development of preeclampsia, that is, immune maladaptation does not seem to be involved. Late-onset preeclampsia (>34 weeks' gestation), representing 80% to 90% of preeclampsia in most developed countries with a "Western lifestyle," is strongly associated with maternal cardiometabolic variables (metabolic syndrome). Although the underlying pathophysiology might be quite different, syncytiotrophoblast stress is the final common pathway leading to the maternal syndrome among the subtypes of preeclampsia by causing an imbalance between proangiogenic factors (placental growth factor and vascular endothelial growth factor) and antiangiogenic factors (soluble fms-like tyrosine kinase-1 and soluble endoglin). Low-dose aspirin, started before 16 week's gestation, will prevent up to 60% of early-onset preeclampsia but will not prevent late-onset preeclampsia. Optimizing prepregnancy weight and controlling gestational weight gain may be the most effective ways to prevent preeclampsia.

Different immunoregulatory components at the decidua basalis of oocyte donation pregnancies

Oocyte donation (OD) pregnancies are characterized by more fetal-maternal human leukocyte antigen (HLA) mismatches compared with naturally conceived (NC) and in vitro fertilization (IVF) pregnancies. The maternal immune system has to cope with greater immunogenetic dissimilarity, but involved immunoregulation remains poorly understood. We examined whether the amount of regulatory T cells (Tregs) and immunoregulatory cytokines in decidua basalis of OD pregnancies differs from NC and IVF pregnancies. The cohort included 25 OD, 11 IVF and 16 NC placentas, maternal peripheral blood, and umbilical cord blood of uncomplicated pregnancies. Placenta slides were stained for FOXP3, IL-10, IL-6, gal-1, TGF-β and Flt-1. Semi-quantitative (FOXP3+ Tregs) and computerized analysis (cytokines) were executed. The blood samples were typed for HLA class I and II to calculate fetal-maternal HLA mismatches. The percentage of Tregs was significantly higher in pregnancies with 4-6 HLA class I mismatches (n = 17), compared to 0-3 mismatches (n = 35; p = 0.04). Cytokine analysis showed significant differences between OD, IVF and NC pregnancies. Flt-1 was significantly lower in pregnancies with 4-6 HLA class I mismatches (p = 0.004), and in pregnancies with 6-10 HLA mismatches in total (p = 0.024). This study suggests that immunoregulation at the fetal-maternal interface in OD pregnancies with more fetal-maternal HLA mismatches is altered.

Uncomplicated oocyte donation pregnancies display an elevated CD163-positive type 2 macrophage load in the decidua, which is associated with fetal-maternal HLA mismatches

PROBLEM

The embryo of an oocyte donation (OD) pregnancy is completely allogeneic to the mother, which may challenge the maternal immune system to tolerize the fetus. Decidual macrophages are essential in maintaining a healthy pregnancy, and type 2 macrophages may exhibit immune suppressive activity. We hypothesized that the composition of decidual macrophages is different between uncomplicated OD pregnancies and non-OD in vitro fertilization (IVF) pregnancies, and is related to fetal-maternal incompatibility.

METHOD OF STUDY

Women with uncomplicated pregnancy were enrolled: 25 singleton OD pregnancies and 17 non-OD IVF pregnancies. The extent of immunohistochemical staining of CD14 (pan-macrophage marker) and CD163 (type 2 macrophage marker) in both decidua basalis and parietalis was quantitated by digital image analysis. Maternal and fetal DNA was typed for human leukocyte antigen (HLA)-A, -B, C, -DRB1, and -DQB1, and fetal-maternal HLA mismatches were calculated.

RESULTS

OD pregnancies showed a higher percentage of CD163+ staining (P = .040) and higher CD163/CD14 ratio (P = .032) in the parietalis than non-OD IVF. The OD group was separated into a semi-allogeneic group (≤5 fetal maternal HLA mismatches) and a fully allogeneic group (> 5 mismatches). The HLA-fully-allogeneic OD group, but not the HLA-semi-allogeneic OD group, showed significantly elevated CD163/CD14 ratio in the parietalis compared with the non-OD IVF group (P < .05).

CONCLUSIONS

Uncomplicated OD pregnancies display a higher CD163-positive cell fraction in the total decidual macrophage population compared to autologous pregnancies, which may suggest that a local type 2 macrophage-related mechanism is needed to compensate for the higher fetal-maternal HLA mismatch load.

Mifepristone regulates macrophage-mediated natural killer cells function in decidua

Mifepristone has been used for first-trimester abortion and contraception. Nevertheless, its functional mechanism still needs to be elucidated. Decidua tissues were collected from 40 pregnant women who received (20 patients) or did not receive (20 patients) mifepristone. Immunofluorescence was used to analyze the effect of mifepristone on the quantity of CD56 and CD206 in decidua. in vitro assay, NK cells were isolated from decidua tissue and macrophages were induced from THP-1 cells. NK cells were co-cultured with macrophages pre-treated different concentrations of mifepristone (0 nmol/L, 200 nmol/L, 1800 nmol/L, and 25000 nmol/L); the cells' cytotoxicity and migration ability were analyzed using MTT assay and transwell assay, respectively. Si-TGF-β1, which was utilized to knock down the TGF-β1 expression in macrophages and human recombinant TGF-β1 were used to verify whether TGF-β1 was involved in the mifepristone regulation of NK cells function. The quantity of CD56 and CD206 decreased after mifepristone treatment. Moreover, the NK cells' cytotoxicity and migration ability were significantly increased by macrophages pre-treated with mifepristone in a dose-dependent manner. Moreover, compared with the si-NC group, the MTT absorbance rate of NK cells was significantly increased in the si-TGF-β1 group and was decreased in the human recombinant TGF-β1 group. Our data suggest that mifepristone, which regulates NK cells function through macrophages, was associated with the changes in TGF-β1 secreted by macrophages. This may be one of the mechanisms of mifepristone acting as contraceptive and abortion drugs at the maternal-fetal interface.

Autophagy Process in Trophoblast Cells Invasion and Differentiation: Similitude and Differences With Cancer Cells

Early human placental development begins with blastocyst implantation, then the trophoblast differentiates and originates the cells required for a proper fetal nutrition and placental implantation. Among them, extravillous trophoblast corresponds to a non-proliferating trophoblast highly invasive that allows the vascular remodeling which is essential for appropriate placental perfusion and to maintain the adequate fetal growth. This process involves different placental cell types as well as molecules that allow cell growth, cellular adhesion, tissular remodeling, and immune tolerance. Remarkably, some of the cellular processes required for proper placentation are common between placental and cancer cells to finally support tumor growth. Indeed, as in placentation trophoblasts invade and migrate, cancer cells invade and migrate to promote tumor metastasis. However, while these processes respond to a controlled program in trophoblasts, in cancer cells this regulation is lost. Interestingly, it has been shown that autophagy, a process responsible for the degradation of damaged proteins and organelles to maintain cellular homeostasis, is required for invasion of trophoblast cells and for vascular remodeling during placentation. In cancer cells, autophagy has a dual role, as it has been shown both as tumor promoter and inhibitor, depending on the stage and tumor considered. In this review, we summarized the similarities and differences between trophoblast cell invasion and cancer cell metastasis specifically evaluating the role of autophagy in both processes.

Cell death mechanisms and their roles in pregnancy related disorders

Autophagy and apoptosis are catabolic pathways essential for homeostasis. They play a crucial role for normal placental and fetal development. These cell death mechanisms are exaggerated in placental disorders such as preeclampsia, intrauterine growth restriction (IUGR) and gestational diabetes mellitus (GDM). Apoptosis is widely studied, highly controlled and regulated whereas; autophagy is an orderly degradation and recycling of the cellular components. Cellular senescence may be initiated by a variety of stimuli, including hypoxia, oxidative stress, reduction in survival signals and nutrition deprivation. Apoptosis is regulated by two types of pathways intrinsic and extrinsic. Extrinsic pathway is initiated by apoptosis inducing cells such as macrophages, natural killer cells whereas; intrinsic pathway is initiated in response to DNA damage, cell injury and lack of oxygen. In autophagy, the cell or organelles undergo lysosomal degradation. Placental apoptosis increases as the gestation progresses while autophagy plays a role in trophoblast differentiation and invasion. In pregnancy disorders like preeclampsia and IUGR, proapoptotic markers such as caspase 3, 8, BAX are higher and antiapoptotic markers like Bcl-2 are lower. In GDM, apoptotic markers are reduced resulting in increased placental mass and fetal macrosomia. Apoptosis in the pathological pregnancies is also influenced by the reduced levels of micronutrients and long chain polyunsaturated fatty acids resulting in disturbed placental biology. This chapter describes the role of various key molecular events involved in cellular senescence and the various factors influencing them. This will help identify future therapeutic strategies for better management of these processes.

Hypertensive disorders of pregnancy by oocyte donation pregnancy in Japanese women aged 40 years or older: a single-center retrospective cohort study

This study aimed to examine the incidence of hypertensive disorders of pregnancy (HDP) among Japanese women with oocyte donation pregnancy (ODP) aged 40 years or older and estimate whether the women with ODP were more likely to develop HDP than those with autologous oocyte pregnancy (AOP) and spontaneous pregnancy (SP). In our study (N = 1361), the proportions of women who developed HDP were 20.5%, 12.8%, and 7.6% for ODP, AOP, and SP, respectively. After adjustment of covariables, the women with ODP were more likely to develop HDP than those with AOP or SP.

Placental disorders of pregnancy in subsequent IVF pregnancies - a sibling cohort

RESEARCH QUESTION

To assess whether the incidence of placental disorders of pregnancy decreases with increasing parity in repeat IVF pregnancies, in the same way as natural pregnancies.

DESIGN

This was a retrospective cohort of deliveries between November 2008 and January 2020, in a single university-affiliated medical centre. The study included women with only IVF-attained singleton pregnancies (no natural conception) with at least two deliveries, and compared the obstetric and perinatal outcomes between first, second and third deliveries. Each woman served as her own control. The primary outcome was the incidence of placental-related disorders of pregnancy, defined as small for gestational age (SGA) neonates and/or pre-eclampsia.

RESULTS

A total of 307 first deliveries, 307 second deliveries and 49 third deliveries by the same women were compared. A trend for a decreased rate of pre-eclampsia was noted with increased parity (P = 0.06) and a significant decrease in the rate of SGA: 11.7% for first delivery, 7.8% for second delivery and 2.0% for third (P = 0.04). This difference in SGA incidence was maintained in a matched sub-analysis of the 49 women with three deliveries (P = 0.04), and after adjustment for fresh/frozen embryo transfer (P = 0.03). Although SGA and pre-eclampsia were generally more common in IVF than natural pregnancies, their decrease with increasing parity mimicked that in natural pregnancies.

CONCLUSION

IVF pregnancies are associated with an increased risk of placental disorders of pregnancy. However, they exhibit a decrease in incidence with increasing parity.

Decidual memory T-cell subsets and memory T-cell stimulatory cytokines in early- and late-onset preeclampsia

PROBLEM

Preeclampsia is a major cause of fetal and maternal mortality and morbidity. Disturbed fetal-maternal immune tolerance, and therewith memory T cells, might be involved in its etiology. This study aims to give insight into memory T-cell populations and its associated cytokines in the decidual layers in early-onset preeclampsia (EO-PE) and late-onset preeclampsia (LO-PE).

METHOD OF STUDY

Lymphocytes were isolated from the decidua parietalis and basalis from EO-PE (n = 6), LO-PE (n = 8) and healthy (n = 15) pregnancies. CD4+ and CD8+ central- (CCR7+ ), effector- (CCR7- ), tissue resident- (CD103+ ), and regulatory- (Foxp3+ ) memory cell (CD45RO+ ) populations and their activation status (CD69+ ) were analyzed using flow cytometry. qRT-PCR analysis was performed on decidua parietalis and basalis biopsies to detect mRNA expression of interferon-gamma, interleukin-1B, IL2, IL6, IL7, IL8, IL10, IL15, and IL23.

RESULTS

CD4+ central-memory (CM) cell proportions were lower in the decidua parietalis in LO-PE (P < .0001) and EO-PE (P < .01) compared to healthy pregnancies. CD8+ memory (P < .05) and CD8+ CM (P < .01) cell proportions were also lower in the decidua parietalis in EO-PE compared to healthy pregnancies. This was accompanied by higher IL15 (P < .05) and IL23 (P < .05) and lower IL7 (P < .05) mRNA expression in decidua basalis biopsies from EO-PE compared to healthy pregnancies, analyzed by qPCR.

CONCLUSION

In conclusion, decidual memory T-cell proportions, their activation status, and associated cytokines are altered in preeclampsia and might therefore be involved in fetal-maternal immune tolerance and the pathophysiology of preeclampsia.

Decreased expression of ligands of placental immune checkpoint inhibitors in uncomplicated and preeclamptic oocyte donation pregnancies

Oocyte donation (OD) pregnancies are characterized by a complete immunogenetic dissimilarity between mother and fetus, which requires enhanced immunoregulation compared to naturally conceived (NC) pregnancies. The trophoblast expresses co-inhibitory ligands crucial for regulation of the maternal T cell response. Therefore, we studied the role of placental immune checkpoint inhibitors for the establishment of fetal tolerance and their relation to the development of preeclampsia in OD compared to NC pregnancies. Placental tissue from uncomplicated OD (n = 21) and NC (n = 21) pregnancies, and OD (n = 9) and NC (n = 15) pregnancies complicated with preeclampsia were studied. Protein expression of co-inhibitory ligands PD-L1 and CD200 was double blind semi-quantitatively determined by immunohistochemistry. Messenger RNA expression of PD-L1, CD200 and indoleamine 2,3-dioxygenase (IDO) was determined using qPCR. Decreased PD-L1 and CD200 protein expression and increased IDO mRNA expression was observed in uncomplicated OD versus NC pregnancies (all p < 0.05). CD200 protein expression was positively correlated with PD-L1 expression in all groups, with the number of HLA total mismatches and with HLA class I mismatches in uncomplicated OD cases (all p < 0.05). Preeclamptic cases showed lower PD-L1 protein and CD200 protein and mRNA expression in OD compared to NC pregnancies (all p < 0.05). This study shows that signaling by co-inhibitory PD-L1 and CD200 and by immunosuppressive IDO is altered in the placenta of OD pregnancies, suggesting a contribution to the higher risk for preeclampsia. These insights provide future prospects in unraveling the immune paradox of oocyte pregnancy, which are applicable for better risk management and treatment of uncomplicated and preeclamptic pregnancies.

Pregnancy outcomes following oocyte donation

The use of oocyte donation (OD) has increased continuously over the last three decades, and it is now an indispensable part of assisted reproductive technology (ART). With OD, it has become possible to overcome the biological barrier of ovarian follicle pool depletion and the general age-related decline in fertility. This review contains a thorough appraisal of the safety of OD with an analysis of short-term pregnancy outcomes. Salient up-to-date evidence was evaluated, which revealed that in comparison with both IVF with autologous oocytes, and naturally conceived pregnancies, there is: (i) an increased risk of hypertensive disorders of pregnancy and preeclampsia; (ii) an increased risk of low birth weight and preterm birth and (iii) an increased risks of obstetric emergencies, following OD treatment. As a precaution, it is therefore highly encouraged to perform only single embryo transfer (SET) and to prescribe prophylactic low-dose aspirin during OD pregnancies.

Analysis of TCR Repertoire and PD-1 Expression in Decidual and Peripheral CD8+ T Cells Reveals Distinct Immune Mechanisms in Miscarriage and Preeclampsia

CD8⁺ T cells, the most abundant T cell subset in the decidua, play a critical role in the maintenance of pregnancy. The majority of decidual CD8⁺ T cells have an effector memory phenotype, while those in the peripheral blood display a naive phenotype. An increased amount of highly differentiated CD8⁺ T cells in the decidua indicates local antigen stimulation and expansion, albeit these CD8⁺ T cells are suppressed. In decidual CD8⁺ T cells, co-inhibitory molecules such as PD-1, TIM-3, LAG-3, and CTLA-4 are upregulated, reflecting the suppression of cytotoxicity. Previous studies established the importance of the PD-1/PD-L1 interaction for feto-maternal tolerance. CD8⁺ T cells could directly recognize fetal-specific antigens, such as HLA-C, expressed by trophoblasts. However, although fetal-specific CD8⁺ T cells have been reported, their TCR repertoires have not been identified. In this study, we analyzed the TCR repertoires of effector memory CD8⁺ T cells (CD8⁺ EM cells) and naive CD8⁺ T cells (CD8⁺ N cells) in the decidua and peripheral blood of women with normal or complicated pregnancy and examined PD-1 expression at a single-cell level to verify whether antigen-specific CD8⁺ T cells accumulate in the decidua and to identify immunological differences related to the suppression of antigen-specific CD8⁺ T cells between normal pregnancy, miscarriage, and preeclampsia. We observed that some TCRβ repertoires, which might recognize fetal or placental antigens, were clonally expanded. The population size of clonally expanded CD8⁺ EM cells was higher in the decidua than in the peripheral blood. CD8⁺ EM cells began to express PD-1 during the course of normal pregnancy. We found that the total proportion of decidual CD8⁺ EM cells not expressing PD-1 was increased both in miscarriage and in preeclampsia cases, although a different mechanism was responsible for this increase. The amount of cytotoxic CD8⁺ EM cells increased in cases of miscarriage, whereas the expression of PD-1 in clonally expanded CD8⁺ EM cells was downregulated in preeclampsia cases. These results demonstrated that decidual CD8⁺ EM cells were able to recognize fetal-specific antigens at the feto-maternal interface and could easily induce fetal rejection.

The Role of Macrophages in Oocyte Donation Pregnancy: A Systematic Review

The embryo of an oocyte donation (OD) pregnancy is completely allogeneic to the mother, which leads to a more serious challenge for the maternal immune system to tolerize the fetus. It is thought that macrophages are essential in maintaining a healthy pregnancy, by acting in immunomodulation and spiral arterial remodeling. OD pregnancies represent an interesting model to study complex immunologic interactions between the fetus and the pregnant woman since the embryo is totally allogeneic compared to the mother. Here, we describe a narrative review on the role of macrophages and pregnancy and a systematic review was performed on the role of macrophages in OD pregnancies. Searches were made in different databases and the titles and abstracts were evaluated by three independent authors. In total, four articles were included on OD pregnancies and macrophages. Among these articles, some findings are conflicting between studies, indicating that more research is needed in this area. From current research, we could identify that there are multiple subtypes of macrophages, having diverse biological effects, and that the ratio between subtypes is altered during gestation and in aberrant pregnancy. The study of macrophages’ phenotypes and their functions in OD pregnancies might be beneficial to better understand the maternal-fetal tolerance system.

Maternal serum perlecan levels in women with preeclampsia

Objective: Perlecan is an extracellular matrix proteoglycan suggested to maintain endothelial functions. We aimed to measure maternal serum perlecan levels in different preeclampsia phenotypes.Methods: This study included 50 women with preeclampsia and 30 healthy pregnant women.Results: Serum perlecan levels were significantly higher (p = 0.016) in preeclamptic women with severe features(n = 23) than preeclampsia patients(n = 27). There were no statistically significant differences in serum perlecan levels between the early-onset preeclampsia(n = 25), late-onset preeclampsia(n = 25), and healthy pregnancies.Conclusion: Our findings suggest that preeclamptic women with severe features have higher serum perlecan levels than women with preeclampsia.

Placental bed research: II. Functional and immunological investigations of the placental bed

Research on the placenta as the interface between the mother and the fetus has been undertaken for some 150 years, and in 2 subsequent reviews, we attempted to summarize the situation. In the first part, we described the discovery of unique physiological modifications of the uteroplacental spiral arteries, enabling them to cope with a major increase in blood flow necessary to ensure proper growth of the fetus. These consist of an invasion of the arterial walls by trophoblast and a progressive disappearance of its normal structure. Researchers then turned to the pathophysiology of the placental bed and in particular to its maternal vascular tree. This yielded vital information for a better understanding of the so-called great obstetrical syndromes (preeclampsia, fetal growth restriction, premature labor and delivery, placenta accreta). Systematic morphological investigations of the uteroplacental vasculature showed that preeclampsia is associated with decreased or failed transformation of spiral arteries and the persistence of endothelial and smooth muscle cells in segments of their myometrial portion. Here we report on recent functional investigations of the placental bed, including in situ biophysical studies of uteroplacental blood flow and vascular resistance, and manipulation of uteroplacental perfusion. These new methodologies have provided a novel way of identifying pregnancies in which remodeling is impaired. In animals it is now possible to manipulate uteroplacental blood flow, leading to an enhancement of fetal growth; this opens the way to trials in abnormal human pregnancies. In this second part, we explored a new, extremely important area of research that deals with the role of specific subsets of leukocytes and macrophages in the placental bed. The human first-trimester decidua is rich in leukocytes called uterine natural killer cells. Both macrophages and uterine natural killer cells increase in number from the secretory endometrium to early pregnancy and play a critical role in mediating the process of spiral artery transformation by inducing initial structural changes. It seems therefore that vascular remodeling of spiral arteries is initiated independently of trophoblast invasion. Dysregulation of the immune system may lead to reproductive failure or pregnancy complications, and in this respect, recent studies have advanced our understanding of the mechanisms regulating immunological tolerance during pregnancy, with several mechanisms being proposed for the development of tolerance to the semiallogeneic fetus. In particular, these include several strategies by which the trophoblast avoids maternal recognition. Finally, an important new dimension is being explored: the likelihood that pregnancy syndromes and impaired uteroplacental vascular remodeling may be linked to future maternal and even the child's cardiovascular disease risk. The functional evidence underlying these observations will be discussed.

Potential influence of the corpus luteum on circulating reproductive and volume regulatory hormones, angiogenic and immunoregulatory factors in pregnant women

Cardiovascular function is impaired and preeclampsia risk elevated in women conceiving by in vitro fertilization (IVF) in the absence of a corpus luteum (CL). Here, we report the serial evaluation of hormones and other circulating factors in women who conceived with (or without) IVF. After a prepregnancy baseline, the study participants (n = 19-24/cohort) were evaluated six times during pregnancy and once postpartum (~1.6 yr). IVF pregnancies were stratified by protocol and CL number, i.e., ovarian stimulation (>1 CL) or hypothalamic-pituitary suppression (0 CL) versus spontaneous conceptions (1 CL). Results include the following: 1) relaxin was undetectable throughout pregnancy (including late gestation) in the 0 CL cohort, but markedly elevated in ~50% of women in the >1 CL cohort; 2) progesterone, plasma renin activity, and aldosterone transiently surged at 5-6 gestational weeks in the >1 CL group; 3) soluble vascular endothelial growth factor-1 (sFLT-1) abruptly increased between 5-6 and 7-9 gestational weeks in all three participant cohorts, producing a marked elevation in sFLT-1/PLGF (placental growth factor) ratio exceeding any other time point during pregnancy; 4) sFLT-1 was higher throughout most of gestation in both IVF cohorts with or without abnormal obstetrical outcomes; 5) during pregnancy, C-reactive protein (CRP) increased in 0 and 1 CL, but not >1 CL cohorts; and 6) plasma protein, but not hemoglobin, was lower in the >1 CL group throughout gestation. The findings highlight that, compared with spontaneously conceived pregnancy, the maternal milieu of IVF pregnancy is not physiologic, and the specific perturbations vary according to IVF protocol and CL status.

Current Understanding of Autophagy in Pregnancy

Autophagy is an evolutionarily conserved process in eukaryotes to maintain cellular homeostasis under environmental stress. Intracellular control is exerted to produce energy or maintain intracellular protein quality controls. Autophagy plays an important role in embryogenesis, implantation, and maintenance of pregnancy. This role includes supporting extravillous trophoblasts (EVTs) that invade the decidua (endometrium) until the first third of uterine myometrium and migrate along the lumina of spiral arterioles under hypoxic and low-nutrient conditions in early pregnancy. In addition, autophagy inhibition has been linked to poor placentation—a feature of preeclamptic placentas—in a placenta-specific autophagy knockout mouse model. Studies of autophagy in human placentas have revealed controversial results, especially with regard to preeclampsia and gestational diabetes mellitus (GDM). Without precise estimation of autophagy flux, wrong interpretation would lead to fixed tissues. This paper presents a review of the role of autophagy in pregnancy and elaborates on the interpretation of autophagy in human placental tissues.

The International Federation of Gynecology and Obstetrics (FIGO) initiative on pre-eclampsia: A pragmatic guide for first-trimester screening and prevention

Pre‐eclampsia (PE) is a multisystem disorder that typically affects 2%–5% of pregnant women and is one of the leading causes of maternal and perinatal morbidity and mortality, especially when the condition is of early onset. Globally, 76 000 women and 500 000 babies die each year from this disorder. Furthermore, women in low‐resource countries are at a higher risk of developing PE compared with those in high‐resource countries. Although a complete understanding of the pathogenesis of PE remains unclear, the current theory suggests a two‐stage process. The first stage is caused by shallow invasion of the trophoblast, resulting in inadequate remodeling of the spiral arteries. This is presumed to lead to the second stage, which involves the maternal response to endothelial dysfunction and imbalance between angiogenic and antiangiogenic factors, resulting in the clinical features of the disorder. Accurate prediction and uniform prevention continue to elude us. The quest to effectively predict PE in the first trimester of pregnancy is fueled by the desire to identify women who are at high risk of developing PE, so that necessary measures can be initiated early enough to improve placentation and thus prevent or at least reduce the frequency of its occurrence. Furthermore, identification of an “at risk” group will allow tailored prenatal surveillance to anticipate and recognize the onset of the clinical syndrome and manage it promptly. PE has been previously defined as the onset of hypertension accompanied by significant proteinuria after 20 weeks of gestation. Recently, the definition of PE has been broadened. Now the internationally agreed definition of PE is the one proposed by the International Society for the Study of Hypertension in Pregnancy (ISSHP). According to the ISSHP, PE is defined as systolic blood pressure at ≥140 mm Hg and/or diastolic blood pressure at ≥90 mm Hg on at least two occasions measured 4 hours apart in previously normotensive women and is accompanied by one or more of the following new‐onset conditions at or after 20 weeks of gestation: 1.Proteinuria (i.e. ≥30 mg/mol protein:creatinine ratio; ≥300 mg/24 hour; or ≥2 + dipstick); 2.Evidence of other maternal organ dysfunction, including: acute kidney injury (creatinine ≥90 μmol/L; 1 mg/dL); liver involvement (elevated transaminases, e.g. alanine aminotransferase or aspartate aminotransferase >40 IU/L) with or without right upper quadrant or epigastric abdominal pain; neurological complications (e.g. eclampsia, altered mental status, blindness, stroke, clonus, severe headaches, and persistent visual scotomata); or hematological complications (thrombocytopenia–platelet count <150 000/μL, disseminated intravascular coagulation, hemolysis); or 3.Uteroplacental dysfunction (such as fetal growth restriction, abnormal umbilical artery Doppler waveform analysis, or stillbirth). It is well established that a number of maternal risk factors are associated with the development of PE: advanced maternal age; nulliparity; previous history of PE; short and long interpregnancy interval; use of assisted reproductive technologies; family history of PE; obesity; Afro‐Caribbean and South Asian racial origin; co‐morbid medical conditions including hyperglycemia in pregnancy; pre‐existing chronic hypertension; renal disease; and autoimmune diseases, such as systemic lupus erythematosus and antiphospholipid syndrome. These risk factors have been described by various professional organizations for the identification of women at risk of PE; however, this approach to screening is inadequate for effective prediction of PE. PE can be subclassified into: 1.Early‐onset PE (with delivery at <34+0 weeks of gestation); 2.Preterm PE (with delivery at <37+0 weeks of gestation); 3.Late‐onset PE (with delivery at ≥34+0 weeks of gestation); 4.Term PE (with delivery at ≥37+0 weeks of gestation). These subclassifications are not mutually exclusive. Early‐onset PE is associated with a much higher risk of short‐ and long‐term maternal and perinatal morbidity and mortality. Obstetricians managing women with preterm PE are faced with the challenge of balancing the need to achieve fetal maturation in utero with the risks to the mother and fetus of continuing the pregnancy longer. These risks include progression to eclampsia, development of placental abruption and HELLP (hemolysis, elevated liver enzyme, low platelet) syndrome. On the other hand, preterm delivery is associated with higher infant mortality rates and increased morbidity resulting from small for gestational age (SGA), thrombocytopenia, bronchopulmonary dysplasia, cerebral palsy, and an increased risk of various chronic diseases in adult life, particularly type 2 diabetes, cardiovascular disease, and obesity. Women who have experienced PE may also face additional health problems in later life, as the condition is associated with an increased risk of death from future cardiovascular disease, hypertension, stroke, renal impairment, metabolic syndrome, and diabetes. The life expectancy of women who developed preterm PE is reduced on average by 10 years. There is also significant impact on the infants in the long term, such as increased risks of insulin resistance, diabetes mellitus, coronary artery disease, and hypertension in infants born to pre‐eclamptic women. The International Federation of Gynecology and Obstetrics (FIGO) brought together international experts to discuss and evaluate current knowledge on PE and develop a document to frame the issues and suggest key actions to address the health burden posed by PE. FIGO's objectives, as outlined in this document, are: (1) To raise awareness of the links between PE and poor maternal and perinatal outcomes, as well as to the future health risks to mother and offspring, and demand a clearly defined global health agenda to tackle this issue; and (2) To create a consensus document that provides guidance for the first‐trimester screening and prevention of preterm PE, and to disseminate and encourage its use. Based on high‐quality evidence, the document outlines current global standards for the first‐trimester screening and prevention of preterm PE, which is in line with FIGO good clinical practice advice on first trimester screening and prevention of pre‐eclampsia in singleton pregnancy.1 It provides both the best and the most pragmatic recommendations according to the level of acceptability, feasibility, and ease of implementation that have the potential to produce the most significant impact in different resource settings. Suggestions are provided for a variety of different regional and resource settings based on their financial, human, and infrastructure resources, as well as for research priorities to bridge the current knowledge and evidence gap. To deal with the issue of PE, FIGO recommends the following: Public health focus: There should be greater international attention given to PE and to the links between maternal health and noncommunicable diseases (NCDs) on the Sustainable Developmental Goals agenda. Public health measures to increase awareness, access, affordability, and acceptance of preconception counselling, and prenatal and postnatal services for women of reproductive age should be prioritized. Greater efforts are required to raise awareness of the benefits of early prenatal visits targeted at reproductive‐aged women, particularly in low‐resource countries. Universal screening: All pregnant women should be screened for preterm PE during early pregnancy by the first‐trimester combined test with maternal risk factors and biomarkers as a one‐step procedure. The risk calculator is available free of charge at https://fetalmedicine.org/research/assess/preeclampsia. FIGO encourages all countries and its member associations to adopt and promote strategies to ensure this. The best combined test is one that includes maternal risk factors, measurements of mean arterial pressure (MAP), serum placental growth factor (PLGF), and uterine artery pulsatility index (UTPI). Where it is not possible to measure PLGF and/or UTPI, the baseline screening test should be a combination of maternal risk factors with MAP, and not maternal risk factors alone. If maternal serum pregnancy‐associated plasma protein A (PAPP‐A) is measured for routine first‐trimester screening for fetal aneuploidies, the result can be included for PE risk assessment. Variations to the full combined test would lead to a reduction in the performance screening. A woman is considered high risk when the risk is 1 in 100 or more based on the first‐trimester combined test with maternal risk factors, MAP, PLGF, and UTPI. Contingent screening: Where resources are limited, routine screening for preterm PE by maternal factors and MAP in all pregnancies and reserving measurements of PLGF and UTPI for a subgroup of the population (selected on the basis of the risk derived from screening by maternal factors and MAP) can be considered. Prophylactic measures: Following first‐trimester screening for preterm PE, women identified at high risk should receive aspirin prophylaxis commencing at 11–14+6 weeks of gestation at a dose of ~150 mg to be taken every night until 36 weeks of gestation, when delivery occurs, or when PE is diagnosed. Low‐dose aspirin should not be prescribed to all pregnant women. In women with low calcium intake (<800 mg/d), either calcium replacement (≤1 g elemental calcium/d) or calcium supplementation (1.5–2 g elemental calcium/d) may reduce the burden of both early‐ and late‐onset PE.

TGFb1 suppresses the activation of distinct dNK subpopulations in preeclampsia

BACKGROUND

Decidual natural killer (dNK) cells are the predominant lymphocytes accumulated at the maternal-fetal interface. Regulatory mechanism of dNK cells in preeclampsia, a gestational complication characterized by high blood pressure and increased proteinuria occurring after 20 weeks pregnancy, is not completely understood.

METHODS

Multi-parameter flow cytometry is applied to investigate the phenotype and function of dNK cells freshly isolated from decidual samples or conditionally cultured by TGFb stimulation.

FINDINGS

In preeclampsia, we documented elevated numbers of CD56⁺ CD3^- dNK cells in close proximity to Foxp3⁺ regulatory T (Treg) cells within the decidua. In vitro experiments using dNK cells from early gestation showed that dNK activation (IFNG, IL-8 and CD107a) can be downregulated by Treg cells. The expression of these markers by dNK cells was significantly lower in preeclampsia. We also observed a positive correlation between the expression of dNK activation receptors (NKp30 and NKG2D) and the expression of IFNG in specific dNK subsets. TGFb levels are increased in the decidua of preeclamptic pregnancies. We analyzed co-expression of activation (IFNG/IL-8/CD107a) and angiogenic (VEGF) markers in dNK cells. TGFb treatment reduced while blockade of TGFb increased co-expression of these markers.

INTERPRETATION

Our findings suggest that elevated decidual TGFb1 supresses the activation of specific subsets of dNK which in turn contributes to the uteroplacental pathology associated with the onset of preeclampsia.

Polysaccharides Extracted from Rhizoma Pleionis Have Antitumor Properties In Vitro and in an H22 Mouse Hepatoma Ascites Model In Vivo

Malignant ascites is a highly severe and intractable complication of advanced or recurrent malignant tumors that is often immunotherapy-resistant. Rhizoma Pleionis is widely used in traditional medicine as an antimicrobial and anticancer agent, but its effectiveness in treating malignant ascites is unclear. In the current study, we investigated the effect of polysaccharides isolated from Rhizoma Pleionis (PRP) on murine hepatocarcinoma H22 cells in an ascites model. We have found that the main components of PRP, that presented a relative molecular weight of 383.57 kDa, were mannose and glucose. We also found that PRP reduced the occurrence of abdominal ascites and increased survival in our mouse model. An immune response in the ascites tumor model was observed by performing a lymphocytes proliferation experiment and an E-rosette test. The ratios of CD8+ cytotoxic T cells and NK cells in the spleen were examined by flow cytometry, and the mRNA expression of Foxp3+in CD4⁺CD25⁺ (T regulatory Tregs) was measured by RT-PCR (reverse transcription-polymerase chain reaction). The levels of the cytokines TNF-α (tumor necrosis factor), VEGF (vascular endothelial growth factor), IL-2 (interleukin), and IFN-γ (interferon) in the serum and ascites supernatants were measured by ELISA. The expression of Foxp3 and Stat3 in peritoneal cells in the mouse model was measured by immunocytochemistry. The results indicated that PRP increased H22 tumor cell apoptosis in vivo by activating and enhancing the immune response. Furthermore, the effects of PRP on the proliferation of H22 cells were assessed by the CCK8 assay, Hoechest 33258, and TUNEL staining in vitro. We found that PRP suppressed the proliferation of H22 tumor cells but had no effect on BRL (Big rat liver) -3A rat hepatoma normal cells in vitro. Next, we investigated the underlying immunological mechanism by which PRP inhibits malignant ascites. PRP induced tumor cell apoptosis by inhibiting the Jak1⁻Stat3 pathway and by activating Caspase-3 and Caspase-8 to increase the Bax/Bcl-2 ratio. Collectively, our results indicate that PRP exhibits significant antitumor properties in H22 cells in vivo and in vitro, indicating that PRP may be used as a new therapeutic drug for cancer treatment.

Autophagy in the placenta

Autophagy is an evolutionarily conserved catalytic process by which cytoplasmic components including damaged macromolecules and organelles are degraded. The role of autophagy includes adaptive responses to nutrition deprivation or intracellular stimuli. Although autophagosomes were first observed in early 1960s, it was 1990s that autophagy-related genes in yeast were identified and studied. Nowadays, the molecular machinery of autophagy and signaling pathway to various stimuli are almost outlined. Dysregulation of autophagic activity has been implicated in many human diseases including neurodegenerative diseases, infection and inflammation, and malignancies. However, since current understanding of autophagy in placenta is just at the beginning, this paper aims to provide general information on autophagy (part I) and to summarize articles on autophagy in human placenta (part II). This review article will serve as a basis for further researches on autophagy in relation to human pregnancy and its complications.

Evidence of Placental Autophagy during Early Pregnancy after Transfer of In Vitro Produced (IVP) Sheep Embryos

Pregnancies obtained by Assisted Reproductive Technologies (ART) are associated with limited maternal nutrient uptake. Our previous studies shown that in vitro culture of sheep embryos is associated with vascularization defects in their placentae and consequent reduction of embryo growth. Autophagy is a pro-survival cellular mechanism triggered by nutrient insufficiency. Therefore, the goal of our present study was to determine if autophagy is involved in early placental development after transfer of in vitro produced (IVP) embryos. To do this, placentae obtained following transfer of IVP sheep embryos were compared with placentae obtained after natural mating (control-CTR). The placentae were collected on day 20 post-fertilization and post-mating, respectively, and were analyzed using molecular (qPCR), ultrastructural and histological/immunological approaches. Our results show drastically increased autophagy in IVP placentae: high levels of expression (p<0.05) of canonical markers of cellular autophagy and a high proportion of autophagic cells (35.08%; p<0.001) were observed. We conclude that high autophagic activity in IVP placentae can be a successful temporary counterbalance to the retarded vasculogenesis and the reduction of foetal growth observed in pregnancies after transfer of IVP embryos.