N6-methyladenosine dynamics in placental development and trophoblast functions, and its potential role in placental diseases.

N6-methyladenosine (m6A) is the most abundant modification controlling RNA metabolism and cellular functions, but its roles in placental development are still poorly understood. Here, we characterized the synchronization of m6A modifications and placental functions by mapping the m6A methylome in human placentas (n = 3, each trimester), revealing that the dynamic patterns of m6A were associated with gene expression homeostasis and different biological pathways in placental development. Then, we generated trophoblast-specific knockout mice of Wtap, a critical component of methyltransferase complex, and demonstrated that Wtap was essential for trophoblast proliferation, placentation and perinatal growth. Further in vitro experiments which includes cell viability assays and series molecular binding assays demonstrated that WTAP-m6A-IGF2BP3 axis regulated the RNA stability and translation of Anillin (ANLN) and VEGFA, promoting trophoblast proliferation and secretion. Dysregulation of this regulatory axis was observed in placentas from pregnancies with fetal growth restriction (FGR) or preeclampsia, revealing the pathogenic effects of imbalanced m6A modifications. Therefore, our findings provide novel insights into the functions and regulatory mechanisms of m6A modifications in placental development and placental-related gestational diseases.

d-galactose causes embryonic development arrest and placental development disorders in mice by increasing ROS and inhibiting SIRT1/FOXO3a axis.

INTRODUCTION: Does an elevation in d-Galactose (D-Gal) levels within the body contribute to abnormal embryonic development and placental dysfunction during pregnancy? METHODS: Mouse embryos were cultivated to the blastocyst stage under varying concentrations of D-Gal. The blastocyst formation rate was measured, and the levels of reactive oxygen species (ROS), sirtuin 1 (SIRT1), and forkhead box O3a (FOXO3a) in blastocysts were assessed. Mice were intraperitoneally injected with either saline or D-Gal with or without SRT1720. On the 14th day of pregnancy, the fetal absorption rate and placental weight were recorded. Placental levels of superoxide dismutase (SOD) and malondialdehyde (MDA) were determined. The expression of senescence-related factors, such as senescence-associated ß-galactosidase (SA-ß-gal) in the placenta was examined, and the expression of placental SIRT1, FOXO3a and p21 was evaluated by immunohistochemistry and Western blotting. RESULTS: D-Gal adversely affects early embryonic development in vitro, resulting in a decreased blastocyst formation rate. Furthermore, D-Gal downregulates SIRT1 and FOXO3a while increasing ROS levels in blastocysts. Concurrently, D-Gal induces placental dysfunction, characterized by an elevated fetal absorption rate, reduced placental weight, diminished SOD activity, and increased MDA content. The senescence-related factor SA-ß-gal was detected in the placenta, along with altered expression of placental SIRT1, FOXO3a, and p21. The SIRT1 agonist SRT1720 mitigated this damage by increasing SIRT1 and FOXO3a expression. DISCUSSION: The inhibition of early embryonic development and placental dysfunction induced by D-Gal may be attributed to the dysregulation of SIRT1. Activating SIRT1 emerges as a potentially effective strategy for alleviating the adverse effects of D-Gal exposure.

Sociodemographic factor associations with maternal and placental outcomes: A cluster and partial least squares regression analysis.

INTRODUCTION: Maternal social disadvantage adversely affects maternal and offspring health, with limited research on placental outcomes. Therefore, we examined maternal sociodemographic factor associations with placental and birth outcomes in general (Lifeways Cross-Generation Cohort) and at-risk (PEARS Study of mothers with overweight or obesity) populations of pregnant women. METHODS: TwoStep cluster analysis profiled Lifeways mothers (n = 250) based on their age, parity, marital status, household income, private healthcare insurance, homeowner status, and education. Differences in placental and birth outcomes (untrimmed placental weight (PW), birthweight (BW) and BW:PW ratio) between clusters were assessed using one-way ANOVA and chi-square tests. Partial least squares regression analysed individual effects of sociodemographic factors on placental and birth outcomes in Lifeways and PEARS mothers (n = 461). RESULTS: Clusters were classified as "Married Homeowners" (n = 140, 56 %), "Highest Income" (n = 58, 23.2 %) and "Renters" (n = 52, 20.8 %) in the Lifeways Cohort. Renters were younger, more likely to smoke, have a means-tested medical card and more pro-inflammatory diets compared to other clusters (p < 0.01). Compared to Married Homeowners, renters' offspring had lower BW (-259.26 g, p < 0.01), shorter birth length (-1.31 cm, p < 0.01) and smaller head circumference (-0.59 cm, p = 0.02). PLS regression analyses identified nulliparity as having the greatest negative effect on PW (Lifeways and PEARS) while being a homeowner had the greatest positive effect on PW (Lifeways). CONCLUSION: Certain combinations of sociodemographic factors (particularly homeownership) were associated with less favourable lifestyle factors, and with birth, but not placental outcomes. When explored individually, parity contributed to the prediction of placental and birth outcomes in both cohorts of pregnant women.

Current research and evidence gaps on placental development in iron deficiency anemia.

Studying the effects of maternal iron deficiency anemia (IDA) is complex owing to its diverse causes, each independently impacting the placenta and fetus. Simple treatment with iron supplements does not always resolve the anemia. Therefore, delving into how IDA alters placental development at a molecular level is crucial to further optimize treatment. This review addresses the effects of IDA on placental structures and functions, including changes in oxygen levels, blood vessels, and the immune system. Profound understanding of physiological characteristics and regulatory mechanisms of placental development is key to explain the mechanisms of abnormal placental development in pregnancy-associated disorders. In turn, future strategies for the prevention and treatment of pregnancy complications involving the placenta can be devised. These studies are significant for improving human reproductive health, enhancing sociodemographic qualities, and even lifelong wellbeing, a focal point in future placental research.

Dynamic and distinct histone modifications facilitate human trophoblast lineage differentiation.

The placenta serves as an essential organ for fetal growth throughout pregnancy. Histone modification is a crucial regulatory mechanism involved in numerous biological processes and development. Nevertheless, there remains a significant gap in our understanding regarding the epigenetic regulations that influence trophoblast lineage differentiation, a fundamental aspect of placental development. Here, through comprehensive mapping of H3K4me3, H3K27me3, H3K9me3, and H3K27ac loci during the differentiation of trophoblast stem cells (TSCs) into syncytiotrophoblasts (STs) and extravillous trophoblasts (EVTs), we reveal dynamic reconfiguration in H3K4me3 and H3K27ac patterns that establish an epigenetic landscape conducive to proper trophoblast lineage differentiation. We observe that broad H3K4me3 domains are associated with trophoblast lineage-specific gene expression. Unlike embryonic stem cells, TSCs lack robust bivalent domains. Notably, the repression of ST- and EVT-active genes in TSCs is primarily attributed to the weak H3K4me3 signal rather than bivalent domains. We also unveil the inactivation of TSC enhancers precedes the activation of ST enhancers during ST formation. Our results provide a comprehensive global map of diverse histone modifications, elucidating the dynamic histone modifications during trophoblast lineage differentiation.

Why study human embryo development?

Understanding the processes and mechanisms underlying early human embryo development has become an increasingly active and important area of research. It has potential for insights into important clinical issues such as early pregnancy loss, origins of congenital anomalies and developmental origins of adult disease, as well as fundamental insights into human biology. Improved culture systems for preimplantation embryos, combined with the new tools of single cell genomics and live imaging, are providing new insights into the similarities and differences between human and mouse development. However, access to human embryo material is still restricted and extended culture of early embryos has regulatory and ethical concerns. Stem cell-derived models of different phases of human development can potentially overcome these limitations and provide a scalable source of material to explore the early postimplantation stages of human development. To date, such models are clearly incomplete replicas of normal development but future technological improvements can be envisaged. The ethical and regulatory environment for such studies remains to be fully resolved.

Implications for miR-339-5p regulation of trophoblast proliferation and migration in placentas associated with porcine intrauterine growth retardation using integrated transcriptome sequencing analysis.

Placental dysfunction is considered as one of the main etiologies of fetal intrauterine growth retardation (IUGR). MicroRNAs (miRNAs) have been demonstrated to be a vital epigenetic modification involved in regulating the placental function and pregnancy outcomes in mammals. However, the mechanisms underlying placenta-specific miRNAs involved in the occurrence and development of pig IUGR remain unclear. In this work, we compared the placental morphologies of piglets with IUGR and normal birth weight (NBW) by using histomorphological analysis and performed a miRNA-mRNA integrative analysis of the gene expression profiles of IUGR and NBW placentas through RNA sequencing. We also investigated the role of differentially expressed ssc-miR-339-5p/GRIK3 through an in vitro experiment on porcine trophoblast cells (PTr2). IUGR piglets had significantly lower birth weight, placental weight, placental efficiency, and placental villus and capillary densities compared with the NBW piglets (P < 0.05). A total of 81 differentially expressed miRNAs and 726 differentially expressed genes in the placentas were screened out between the IUGR and NBW groups. The miRNA-mRNA interaction networks revealed the key core miRNA (ssc-miR-339-5p) and its corresponding target genes. Subsequently, we found that upregulation of ssc-miR-339-5p significantly inhibited the migration and proliferation of PTr2 cells (P < 0.05). The dual-luciferase reporter system showed that GRIK3 was the target gene of ssc-miR-339-5p, and the transcription level of GRIK3 may be negatively regulated by ssc-miR-339-5p. Additionally, overexpression of ssc-miR-339-5p significantly increased (P < 0.05) the mRNA expression levels of genes involved in the cytokine-cytokine receptor interaction pathway. These results indicate that ssc-miR-339-5p may affect the migration and proliferation of trophoblast cells by regulating the expression of GRIK3 and altering the placental inflammatory response, resulting in a suboptimal morphology and function of the placenta and the development of pig IUGR.

Embryonic statistical analyses reveal 2 growth phenotypes in mouse models of Down syndrome.

BACKGROUND: Down syndrome is associated with several comorbidities, including intellectual disability, growth restriction, and congenital heart defects. The prevalence of Down syndrome-associated comorbidities is highly variable, and intellectual disability, although fully penetrant, ranges from mild to severe. Understanding the basis of this interindividual variability might identify predictive biomarkers of in utero and postnatal outcomes that could be used as endpoints to test the efficacy of future therapeutic interventions. OBJECTIVE: The main objective of this study was to examine if antenatal interindividual variability exists in mouse models of Down syndrome and whether applying statistical approaches to clinically relevant measurements (ie, the weights of the embryo, placenta, and brain) could define cutoffs that discriminate between subgroups of trisomic embryos. STUDY DESIGN: Three commonly used mouse models of Down syndrome (Dp(16)1/Yey, Ts65Dn, and Ts1Cje) and a new model (Ts66Yah) were used in this study. Trisomic and euploid littermate embryos were used from each model with total numbers of 102 for Ts66Yah, 118 for Dp(16)1/Yey, 92 for Ts65Dn, and 126 for Ts1Cje. Placental, embryonic, and brain weights and volumes at embryonic day 18.5 were compared between genotypes in each model. K-mean clustering analysis was applied to embryonic and brain weights to identify severity classes in trisomic embryos, and brain and placental volumetric measurements were compared between genotypes and classes for each strain. In addition, Ts66Yah embryos were examined for malformations because embryonic phenotypes have never been examined in this model. RESULTS: Reduced body and brain weights were present in Ts66Yah, Dp(16)1/Yey, and Ts65Dn embyos. Cluster analysis identified 2 severity classes in trisomic embryos-mild and severe-in all 4 models that were distinguishable using a putative embryonic weight cutoff of <0.5 standard deviation below the mean. Ts66Yah trisomic embryos develop congenital anomalies that are also found in humans with Down syndrome, including congenital heart defects and renal pelvis dilation. CONCLUSION: Statistical approaches applied to clinically relevant measurements revealed 2 classes of phenotypic severity in trisomic mouse models of Down syndrome. Analysis of severely affected trisomic animals may facilitate the identification of biomarkers and endpoints that can be used to prenatally predict outcomes and the efficacy of treatments.

Human Placenta and Evolving Insights into Pathological Changes of Preeclampsia: A Comprehensive Review of the Last Decade.

The placenta, the foremost and multifaceted organ in fetal and maternal biology, is pivotal in facilitating optimal intrauterine fetal development. Remarkably, despite its paramount significance, the placenta remains enigmatic, meriting greater comprehension given its central influence on the health trajectories of both the fetus and the mother. Preeclampsia (PE) and intrauterine fetal growth restriction (IUGR), prevailing disorders of pregnancy, stem from compromised placental development. PE, characterized by heightened mortality and morbidity risks, afflicts 5-7% of global pregnancies, its etiology shrouded in ambiguity. Pertinent pathogenic hallmarks of PE encompass inadequate restructuring of uteroplacental spiral arteries, placental ischemia, and elevated levels of vascular endothelial growth factor receptor-1 (VEGFR-1), also recognized as soluble FMS-like tyrosine kinase-1 (sFlt-1). During gestation, the placental derivation of sFlt-1 accentuates its role as an inhibitory receptor binding to VEGF-A and placental growth factor (PlGF), curtailing target cell accessibility. This review expounds upon the placenta's defining cellular component of the trophoblast, elucidates the intricacies of PE pathogenesis, underscores the pivotal contribution of sFlt-1 to maternal pathology and fetal safeguarding, and surveys recent therapeutic strides witnessed in the past decade.

Effects of dietary supplementation of different levels of gamma-aminobutyric acid on reproductive performance, glucose intolerance, and placental development of gilts.

This study aimed to investigate the effects of dietary gamma-aminobutyric acid (GABA) supplementation on reproductive performance, glucose intolerance, and placental development of gilts during mid-late gestation. Based on the principle of backfat thickness consistency, 124 gilts at 65 d of gestation were assigned to three dietary groups: CON (basic diet, n = 41), LGABA (basic diet supplemented with 0.03% GABA, n = 42), and HGABA (basic diet supplemented with 0.06% GABA, n = 41). The litter performance, glucose tolerance, placental angiogenesis, and nutrients transporters were assessed. The LGABA group improved piglet vitality and placental efficiency and decreased area under the curve of glucose tolerance test compared to the CON group (P < 0.05). Meanwhile, the LGABA group enhanced placental vessel density, platelet endothelial cell adhesion molecule-1 levels and gene expression of fibroblast growth factor 18 (P < 0.05). Furthermore, LGABA showed an uptrend in glucose transporter type 1 mRNA level (P = 0.09). Taken together, this study revealed that the dietary supplementation of 0.03% GABA can improve piglet vitality, glucose intolerance, and placental development of gilts.

Glucose homeostasis and placental development are two key factors influencing reproductive performance of sows. Some studies have reported that gamma-aminobutyric acid (GABA) can improve glucose intolerance and cerebral angiogenesis in mice. Therefore, we hypothesized that GABA can improve reproductive performance, glucose intolerance, and placental development of gilts during mid-late gestation. In this study, gilts were randomly assigned into three groups: CON (basal diet), LGABA (basal diet supplemented with 0.03% GABA), and HGABA (basal diet supplemented with 0.06% GABA). Results showed that the LGABA group significantly improved the piglet viability, glucose intolerance, and placental development compared with the CON group. Therefore, GABA has a good prospect as a feed additive for gilts.

CRISPR screening in human trophoblast stem cells reveals both shared and distinct aspects of human and mouse placental development.

The placenta serves as the interface between the mother and fetus, facilitating the exchange of gases and nutrients between their separate blood circulation systems. Trophoblasts in the placenta play a central role in this process. Our current understanding of mammalian trophoblast development relies largely on mouse models. However, given the diversification of mammalian placentas, findings from the mouse placenta cannot be readily extrapolated to other mammalian species, including humans. To fill this knowledge gap, we performed CRISPR knockout screening in human trophoblast stem cells (hTSCs). We targeted genes essential for mouse placental development and identified more than 100 genes as critical regulators in both human hTSCs and mouse placentas. Among them, we further characterized in detail two transcription factors, DLX3 and GCM1, and revealed their essential roles in hTSC differentiation. Moreover, a gene function-based comparison between human and mouse trophoblast subtypes suggests that their relationship may differ significantly from previous assumptions based on tissue localization or cellular function. Notably, our data reveal that hTSCs may not be analogous to mouse TSCs or the extraembryonic ectoderm (ExE) in which in vivo TSCs reside. Instead, hTSCs may be analogous to progenitor cells in the mouse ectoplacental cone and chorion. This finding is consistent with the absence of ExE-like structures during human placental development. Our data not only deepen our understanding of human trophoblast development but also facilitate cross-species comparison of mammalian placentas.

Gene-network based analysis of human placental trophoblast subtypes identifies critical genes as potential targets of therapeutic drugs.

During early pregnancy, extravillous trophoblasts (EVTs) play a crucial role in modifying the maternal uterine environment. Failures in EVT lineage formation and differentiation can lead to pregnancy complications such as preeclampsia, fetal growth restriction, and pregnancy loss. Despite recent advances, our knowledge on molecular and external factors that control and affect EVT development remains incomplete. Using trophoblast organoid in vitro models, we recently discovered that coordinated manipulation of the transforming growth factor beta (TGFß) signaling is essential for EVT development. To further investigate gene networks involved in EVT function and development, we performed weighted gene co-expression network analysis (WGCNA) on our RNA-Seq data. We identified 10 modules with a median module membership of over 0.8 and sizes ranging from 1005 (M1) to 72 (M27) network genes associated with TGFß activation status or in vitro culturing, the latter being indicative for yet undiscovered factors that shape the EVT phenotypes. Lastly, we hypothesized that certain therapeutic drugs might unintentionally interfere with placentation by affecting EVT-specific gene expression. We used the STRING database to map correlations and the Drug-Gene Interaction database to identify drug targets. Our comprehensive dataset of drug-gene interactions provides insights into potential risks associated with certain drugs in early gestation.

Identification and expression analysis of LEA gene family members in pepper (Capsicum annuum L.).

Pepper (Capsicum annuum L.) is an economically important crop containing capsaicinoids in the seed and placenta, which has various culinary, medical, and industrial applications. Late embryogenesis abundant (LEA) proteins are a large group of hydrophilic proteins participating in the plant stress response and seed development. However, to date there have been no genome-wide analyses of the LEA gene family in pepper. In the present study, 82 LEA genes were identified in the C. annuum genome and classified into nine subfamilies. Most CaLEA genes contain few introns (≤ 2) and are unevenly distributed across 10 chromosomes. Eight pairs of tandem duplication genes and two pairs of segmental duplication genes were identified in the LEA gene family; these duplicated genes were highly conserved and may have performed similar functions during evolution. Expression profile analysis indicated that CaLEA genes exhibited different tissue expression patterns, especially during embryonic development and stress response, particularly in cold stress. Three out of five CaLEA genes showed induced expression upon cold treatment. In summary, we have comprehensively reviewed the LEA gene family in pepper, offering a new perspective on the evolution of this family.

Trophoblast Differentiation: Mechanisms and Implications for Pregnancy Complications.

Placental development is a tightly controlled event, in which cell expansion from the trophectoderm occurs in a spatiotemporal manner. Proper trophoblast differentiation is crucial to the vitality of this gestational organ. Obstructions to its development can lead to pregnancy complications, such as preeclampsia, fetal growth restriction, and preterm birth, posing severe health risks to both the mother and offspring. Currently, the only known treatment strategy for these complications is delivery, making it an important area of research. The aim of this review was to summarize the known information on the development and mechanistic regulation of trophoblast differentiation and highlight the similarities in these processes between the human and mouse placenta. Additionally, the known biomarkers for each cell type were compiled to aid in the analysis of sequencing technologies.

Placental deficiency of the (pro)renin receptor ((P)RR) reduces placental development and functional capacity.

The (pro)renin receptor ((P)RR; also known as ATP6AP2) is a multifunctional receptor. The (P)RR activates the tissue renin-angiotensin system (RAS) and is also involved in regulating integral intracellular pathways such as V-ATPase and Wnt/ß-catenin signalling. Given this, the (P)RR may be associated with essential pathways in placentation, however its role within the context of pregnancy remains poorly characterised. The first trimester/extravillous trophoblast cell line, HTR-8/SVneo, underwent an siRNA knockdown where they were incubated for 24 h with a negative control siRNA or siRNA targeting ATP6AP2 mRNA. xCELLigence real-time cell analysis was performed to assess the effect of ATP6AP2 mRNA knockdown on HTR-8/SVneo cell proliferation, migration, and invasion. In subsequent experiments, GFP-encoding lentiviral packaged gene-constructs were used to knockdown (P)RR expression in the trophectoderm of C57/BL6/CBA-F1 mouse blastocysts. Blastocysts were incubated for 6 h with vehicle (no-virus), control virus (non-targeting shRNA and GFP), or (P)RR-knockdown virus ((P)RR shRNA and GFP) before transfer into recipient pseudo-pregnant Swiss CD1 female mice. Fetal and placental tissues were collected and assessed at embryonic age (EA) 10 and 18. (P)RR levels were measured in the labyrinth zone of day 18 placentae and stereological Merz grid analysis was performed to determine the volumetric distribution of trophoblasts, fetal capillaries, and the maternal blood space. We showed that a reduction of ATP6AP2 expression in HTR-8/SVneo cells in vitro, impaired trophoblast proliferation, migration, and invasion. In vivo, decreasing placental labyrinth (P)RR expression adversely effected placental physiology, decreasing placental trophoblast number and total surface area available for exchange, while also increasing maternal blood space. Additionally, decreased (P)RR affected placental efficacy evident by the reduced fetal-placental weight ratio. Our study shows that the (P)RR is necessary for appropriate placental development and function.

Unveiling the hidden players: The crucial role of transposable elements in the placenta and their potential contribution to pre-eclampsia.

The human placenta is a vital connection between maternal and fetal tissues, allowing for the exchange of molecules and modulation of immune interactions during pregnancy. Interestingly, some of the placenta's unique functions can be attributed to transposable elements (TEs), which are DNA sequences that have mobilised into the genome. Co-option throughout mammalian evolution has led to the generation of TE-derived regulators and TE-derived genes, some of which are expressed in the placenta but silenced in somatic tissues. TE genes encompass both TE-derived genes with a repeat element in the coding region and TE-derived regulatory regions such as alternative promoters and enhancers. Placental-specific TE genes are known to contribute to the placenta's unique functions, and interestingly, they are also expressed in some cancers and share similar functions. There is evidence to support that aberrant activity of TE genes may contribute to placental pathologies, cancer and autoimmunity. In this review, we highlight the crucial roles of TE genes in placental function, and how their dysregulation may lead to pre-eclampsia, a common and dangerous placental condition. We provide a summary of the functional TE genes in the placenta to offer insight into their significance in normal and abnormal human development. Ultimately, this review highlights an opportunity for future research to investigate the potential dysregulation of TE genes in the development of placental pathologies such as pre-eclampsia. Further understanding of TE genes and their role in the placenta could lead to significant improvements in maternal and fetal health.

The transposable element-derived transcript of LIN28B has a placental origin and is not specific to tumours.

Transposable elements (TEs) are genetic elements that have evolved as crucial regulators of human development and cancer, functioning as both genes and regulatory elements. When TEs become dysregulated in cancer cells, they can serve as alternate promoters to activate oncogenes, a process known as onco-exaptation. This study aimed to explore the expression and epigenetic regulation of onco-exaptation events in early human developmental tissues. We discovered co-expression of some TEs and oncogenes in human embryonic stem cells and first trimester and term placental tissues. Previous studies identified onco-exaptation events in various cancer types, including an AluJb SINE element-LIN28B interaction in lung cancer cells, and showed that the TE-derived LIN28B transcript is associated with poor patient prognosis in hepatocellular carcinoma. This study further characterized the AluJb-LIN28B transcript and confirmed that its expression is restricted to the placenta. Targeted DNA methylation analysis revealed differential methylation of the two LIN28B promoters between placenta and healthy somatic tissues, indicating that some TE-oncogene interactions are not cancer-specific but arise from the epigenetic reactivation of developmental TE-derived regulatory events. In conclusion, our findings provide evidence that some TE-oncogene interactions are not limited to cancer and may originate from the epigenetic reactivation of TE-derived regulatory events that are involved in early development. These insights broaden our understanding of the role of TEs in gene regulation and suggest the potential importance of targeting TEs in cancer therapy beyond their conventional use as cancer-specific markers.

Effect of increasing dietary methionine-to-lysine ratio during early gestation on fetal development and piglet birth weight.

It was hypothesized that increasing dietary methionine (Met) for sows in early gestation would have a positive effect on fetal and placental growth and development, thereby also increasing the birth weight of piglets. The objective of the study was to investigate the effect of increasing the total dietary methionine-to-lysine ratio (Met:Lys) from 0.29 (Control diet) to 0.41 (Met diet) from mating to day 50 of gestation. A total of 349 multiparous sows were allocated to either the Control or Met diet group. The sows' backfat thickness was measured pre-farrowing, post-farrowing, and at weaning in the previous cycle and on days 14, 50 and 112 of gestation in the current cycle. On day 50, three Control and six Met sows were slaughtered. In 116 litters, piglets were weighed and measured individually at farrowing. The dietary treatment did not affect the sows' backfat thickness before or during gestation (P > 0.05). The number of liveborn and stillborn piglets at farrowing were similar in both groups (P > 0.05) and no differences in average piglet birth weight, total litter weight at birth or within-litter variation in birth weight (P > 0.05) were observed. In conclusion, increasing the dietary Met:Lys ratio for sows in early gestation had no effect on piglet birth weight.

The immune checkpoint molecule, VTCN1/B7-H4, guides differentiation and suppresses proinflammatory responses and MHC class I expression in an embryonic stem cell-derived model of human trophoblast.

The placenta acts as a protective barrier to pathogens and other harmful substances present in the maternal circulation throughout pregnancy. Disruption of placental development can lead to complications of pregnancy such as preeclampsia, intrauterine growth retardation and preterm birth. In previous work, we have shown that expression of the immune checkpoint regulator, B7-H4/VTCN1, is increased upon differentiation of human embryonic stem cells (hESC) to an in vitro model of primitive trophoblast (TB), that VTCN1/B7-H4 is expressed in first trimester but not term human placenta and that primitive trophoblast may be uniquely susceptible to certain pathogens. Here we report on the role of VTCN1 in trophoblast lineage development and anti-viral responses and the effects of changes in these processes on major histocompatibility complex (MHC) class I expression and peripheral NK cell phenotypes.

Decidual derived exosomal miR-99a-5p targets Ppp2r5a to inhibit trophoblast invasion in response to CeO2NPs exposure.

BACKGROUND: The biological effects of cerium dioxide nanoparticles (CeO2NPs), a novel material in the biomedical field, have attracted widespread attention. Our previous study confirmed that exposure to CeO2NPs during pregnancy led to abnormal trophoblast invasion during early placental development, thereby impairing placental development. The potential mechanisms may be related to low-quality decidualization triggered by CeO2NPs exposure, such as an imbalance in trophoblast invasion regulators secreted by decidual cells. However, the intermediate link mediating the "dialogue" between decidual cells and trophoblasts during this process remains unclear. As an important connection between cells, exosomes participate in the "dialogue" between endometrial cells and trophoblasts. Exosomes transfer bioactive microRNA into target cells, which can target and regulate the level of mRNA in target cells. RESULTS: Here, we constructed a mice primary uterine stromal cell-induced decidualization model in vitro, and detected the effect of CeO2NPs exposure on the expression of decidual-derived exosomal miRNAs by high-throughput sequencing. Bioinformatics analysis and dual-luciferase reporter assays were performed to identify target genes of the screened key miRNAs in regulating trophoblast invasion. Finally, the role of the screened miRNAs and their target genes in regulating trophoblast (HTR-8/SVneo cells) invasion was confirmed. The results showed that CeO2NPs exposure inhibited trophoblast invasion by promoting miR-99a-5p expression in decidual-derived exosomes, and Ppp2r5a is a potential target gene for miR-99a-5p to inhibit trophoblast invasion. CONCLUSIONS: This study revealed the molecular mechanism by which CeO2NPs exposure inhibits trophoblast invasion from the perspective of decidual derived exosomal miRNAs. These results will provide an experimental basis for screening potential therapeutic targets for the negative biological effects of CeO2NPs exposure and new ideas for studying the mechanism of damage to trophoblast cells at the decidual-foetal interface by harmful environmental or occupational factors.