Aspects of human fetoplacental vasculogenesis and angiogenesis. II. Changes during normal pregnancy

Feto-placental and coronary endothelial genes implicated in miscarriage, congenital heart disease and stillbirth, a systematic review and meta-analysis

The first trimester placenta is very rarely investigated for placental vascular formation in developmental or diseased contexts. Defects in placental formation can cause heart defects in the fetus, and vice versa. Determining the causality is therefore difficult as both organs develop concurrently and express many of the same genes. Here, we performed a systematic review to determine feto-placental and coronary endothelial genes implicated in miscarriages, stillbirth and congenital heart defects (CHD) from human genome wide screening studies. 4 single cell RNAseq datasets from human first/early second trimester cardiac and placental samples were queried to generate a list of 1187 endothelial genes. This broad list was cross-referenced with genes implicated in the pregnancy disorders above. 39 papers reported feto-placental and cardiac coronary endothelial genes, totalling 612 variants. Vascular gene variants were attributed to the incidence of miscarriage (8 %), CHD (4 %) and stillbirth (3 %). The most common genes for CHD (NOTCH, DST, FBN1, JAG1, CHD4), miscarriage (COL1A1, HERC1), and stillbirth (AKAP9, MYLK), were involved in blood vessel and cardiac valve formation, with roles in endothelial differentiation, angiogenesis, extracellular matrix signaling, growth factor binding and cell adhesion. NOTCH1, AKAP12, CHD4, LAMC1 and SOS1 showed greater relative risk ratios with CHD. Many of the vascular genes identified were expressed highly in both placental and heart EC populations. Both feto-placental and cardiac vascular genes are likely to result in poor endothelial cell development and function during human pregnancy that leads to higher risk of miscarriage, congenital heart disease and stillbirth.

TGFβ1, SNAIL2, and PAPP-A Expression in Placenta of Gestational Diabetes Mellitus Patients

Background: Gestational diabetes mellitus (GDM) is a pregnancy-related diabetic condition that may cause serious complications. However, its pathogenesis remains unclear. Placental damage due to GDM may lead to several health issues that cannot be ignored. Thus, we aimed to identify the mechanisms underlying GDM by screening differentially expressed genes (DEGs) related to vascular endothelial cells in the GDM databases and verify the expression of these DEGs in the placentas of women afflicted by GDM. Methods: We used GDM microarray datasets integrated from the Gene Expression Omnibus (GEO) database. Functional annotation and protein-protein interaction (PPI) analyses were used to screen DEGs. Placental tissues from 20 pregnant women with GDM and 20 healthy pregnant women were collected, and differential gene expression in the placental tissues was verified via qRT-PCR, western blotting, and immunofluorescence. Results: Bioinformatics analysis revealed three significant DEGs: SNAIL2, PAPP-A, and TGFβ1. These genes were all predicted to be underexpressed in patients with GDM. The results of qRT-PCR, western blot, and immunofluorescence analyses indicated that SNAIL2 and PAPP-A in the placenta tissue of patients with GDM were significantly underexpressed. However, TGFβ1 in the placenta tissues of GDM was significantly overexpressed. Conclusion: SNAIL2, TGFβ1, and PAPP-A may affect the placentas of pregnant women with GDM, warranting further investigation.

Associations between placental hydroxymethylation and birthweight

5-hydroxymethylcytosine (5hmC), formed through the ten-eleven translocation (TET) methylcytosine dioxygenase mediated oxidation of 5-methylcytosine (5mC) at cytosine-phosphate-guanine (CpG) dinucleotides, is believed to mainly serve as an intermediate in the DNA demethylation pathway, though recent evidence suggests that 5hmC may also play a functionally relevant role. We have conducted an epigenome-wide association study (EWAS) to assess the association between placenta 5hmC, obtained through parallel bisulfite and oxidative bisulfite modification of DNA and array-based assessment, and newborn birthweight in the Rhode Island Child Health Study (RICHS). We also assessed whether the removal of 5hmC signal impacts the observed results from traditional epigenome-wide studies that rely on BS modification-based (combined 5mC and 5hmC) assessment alone. We identified 5hmC at one CpG in the CUBN gene to be significantly associated with birthweight (FDR < 0.05) and demonstrate that expression of that gene was also associated with birthweight. Comparison of 5hmC+5mC and 5mC EWAS effect estimates reveal a strong correlation (r = 0.77, p < 0.0001). Our study suggests that traditional assessment of 5mC through bisulfite modification alone provides an accurate assessment of CpG-specific DNA methylation for EWAS studies but was unable to provide evidence of widespread associations between placental 5hmC and birthweight.

Molecular regulators of defective placental and cardiovascular development in fetal growth restriction

Placental insufficiency is one of the major causes of fetal growth restriction (FGR), a significant pregnancy disorder in which the fetus fails to achieve its full growth potential in utero. As well as the acute consequences of being born too small, affected offspring are at increased risk of cardiovascular disease, diabetes and other chronic diseases in later life. The placenta and heart develop concurrently, therefore placental maldevelopment and function in FGR may have profound effect on the growth and differentiation of many organ systems, including the heart. Hence, understanding the key molecular players that are synergistically linked in the development of the placenta and heart is critical. This review highlights the key growth factors, angiogenic molecules and transcription factors that are common causes of defective placental and cardiovascular development.

Revealing the molecular landscape of human placenta: a systematic review and meta-analysis of single-cell RNA sequencing studies

BACKGROUND

With increasing significance of developmental programming effects associated with placental dysfunction, more investigations are devoted to improving the characterization and understanding of placental signatures in health and disease. The placenta is a transitory but dynamic organ adapting to the shifting demands of fetal development and available resources of the maternal supply throughout pregnancy. Trophoblasts (cytotrophoblasts, syncytiotrophoblasts, and extravillous trophoblasts) are placental-specific cell types responsible for the main placental exchanges and adaptations. Transcriptomic studies with single-cell resolution have led to advances in understanding the placenta's role in health and disease. These studies, however, often show discrepancies in characterization of the different placental cell types.

OBJECTIVE AND RATIONALE

We aim to review the knowledge regarding placental structure and function gained from the use of single-cell RNA sequencing (scRNAseq), followed by comparing cell-type-specific genes, highlighting their similarities and differences. Moreover, we intend to identify consensus marker genes for the various trophoblast cell types across studies. Finally, we will discuss the contributions and potential applications of scRNAseq in studying pregnancy-related diseases.

SEARCH METHODS

We conducted a comprehensive systematic literature review to identify different cell types and their functions at the human maternal-fetal interface, focusing on all original scRNAseq studies on placentas published before March 2023 and published reviews (total of 28 studies identified) using PubMed search. Our approach involved curating cell types and subtypes that had previously been defined using scRNAseq and comparing the genes used as markers or identified as potential new markers. Next, we reanalyzed expression matrices from the six available scRNAseq raw datasets with cell annotations (four from first trimester and two at term), using Wilcoxon rank-sum tests to compare gene expression among studies and annotate trophoblast cell markers in both first trimester and term placentas. Furthermore, we integrated scRNAseq raw data available from 18 healthy first trimester and nine term placentas, and performed clustering and differential gene expression analysis. We further compared markers obtained with the analysis of annotated and raw datasets with the literature to obtain a common signature gene list for major placental cell types.

OUTCOMES

Variations in the sampling site, gestational age, fetal sex, and subsequent sequencing and analysis methods were observed between the studies. Although their proportions varied, the three trophoblast types were consistently identified across all scRNAseq studies, unlike other non-trophoblast cell types. Notably, no marker genes were shared by all studies for any of the investigated cell types. Moreover, most of the newly defined markers in one study were not observed in other studies. These discrepancies were confirmed by our analysis on trophoblast cell types, where hundreds of potential marker genes were identified in each study but with little overlap across studies. From 35 461 and 23 378 cells of high quality in the first trimester and term placentas, respectively, we obtained major placental cell types, including perivascular cells that previously had not been identified in the first trimester. Importantly, our meta-analysis provides marker genes for major placental cell types based on our extensive curation.

WIDER IMPLICATIONS

This review and meta-analysis emphasizes the need for establishing a consensus for annotating placental cell types from scRNAseq data. The marker genes identified here can be deployed for defining human placental cell types, thereby facilitating and improving the reproducibility of trophoblast cell annotation.

Advanced magnetic resonance imaging detects altered placental development in pregnancies affected by congenital heart disease

Congenital heart disease (CHD) is the most common congenital malformation and is associated with adverse neurodevelopmental outcomes. The placenta is crucial for healthy fetal development and placental development is altered in pregnancy when the fetus has CHD. This study utilized advanced combined diffusion-relaxation MRI and a data-driven analysis technique to test the hypothesis that placental microstructure and perfusion are altered in CHD-affected pregnancies. 48 participants (36 controls, 12 CHD) underwent 67 MRI scans (50 control, 17 CHD). Significant differences in the weighting of two independent placental and uterine-wall tissue components were identified between the CHD and control groups (both pFDR < 0.001), with changes most evident after 30 weeks gestation. A significant trend over gestation in weighting for a third independent tissue component was also observed in the CHD cohort (R = 0.50, pFDR = 0.04), but not in controls. These findings add to existing evidence that placental development is altered in CHD. The results may reflect alterations in placental perfusion or the changes in fetal-placental flow, villous structure and maturation that occur in CHD. Further research is needed to validate and better understand these findings and to understand the relationship between placental development, CHD, and its neurodevelopmental implications.

Differential Effects of n-3 and n-6 Polyunsaturated Fatty Acids on Placental and Embryonic Growth and Development in Diabetic Pregnant Mice

The present study aimed to investigate the differential effects of n-3 and n-6 polyunsaturated fatty acids (PUFAs) on placental and embryonic development. Pregnant mice were assigned to five groups: healthy control (HC), diabetes mellitus control (DMC), diabetes + low-dose n-3 PUFA (Ln-3), diabetes + high-dose n-3 PUFA (Hn-3), and diabetes + n-6 PUFA (n-6). On E12.5d, the Hn-3 group, but not the n-6 group, had a higher placenta weight. The weight ratio of embryo to placenta in the n-6 group was significantly lower than in the Hn-3 group but higher than in the DMC group. The Hn-3 group had significantly higher protein levels of VEGF, IGF-1, and IGFBP3, while the n-6 group had lower VEGF than the DMC group. Compared with the DMC group, embryonic Cer-16:0 was significantly higher in the Hn-3 group, while embryonic PC (36:6), PC (38:7), and PE (40:7) were significantly lower in the n-6 group. The embryo and placenta weights were positively correlated with placental VEGF, IGFBP3, and embryonic Cer-16:0, and they were negatively correlated with embryonic PC (36:6) and PE (40:7). The weight ratio of embryo to placenta was negatively correlated with embryonic PC (36:6). In addition, embryonic Cer-16:0 was positively correlated with placental VEGF and IGFBP3. In conclusion, n-3 PUFA and n-6 PUFA improved placental and embryonic growth through different mechanisms.

PFAS alters placental arterial vasculature in term human placentae: A prospective pregnancy cohort study

INTRODUCTION

Perfluoroalkyl substances (PFAS) are synthetic chemicals used in industrial and consumer goods that are widely detected in human populations and are associated with adverse health outcomes, including perinatal health risks and child health. One mechanism of influence may be the impact of PFAS exposure on placental structure and function.

OBJECTIVES

The objective of this study is to investigate the relationship between maternal prenatal exposure to PFAS and measures of placental vascularization, and to assess whether changes in vascularization play a role in mediating the impact of PFAS on birth outcomes.

METHODS

Using data from a prospective cohort study, we examined associations between second trimester PFAS (individually and as mixtures using Bayesian kernel machine regression) and placental arterial vasculature in term placentae (N = 158); secondarily we evaluated the degree to which alterations in placental arterial vasculature explained associations between PFAS exposure and birth outcomes. Placental arterial vasculature features were collected from arterial tracings of each placental image.

RESULTS

In both linear regression and mixture models, natural log-transformed perfluorooctanoic acid concentrations were negatively associated with surface vasculature, indexed by the mean distance from arterial end point to perimeter (β = -0.23, 95% CI: -0.41, -0.041); additionally, maximum arterial tortuosity was negatively associated with placental weight (β = -0.19, 95% CI: -0.34, -0.051). There were no reliable differences in effect by fetal sex.

DISCUSSION

The findings provide some of the first evidence of PFAS exposure shaping a key measure of placental vascular function, which may underlie the impact of PFAS on perinatal and child health risks.

Advanced magnetic resonance imaging detects altered placental development in pregnancies affected by congenital heart disease

Congenital heart disease (CHD) is the most common congenital malformation and is associated with adverse neurodevelopmental outcomes. The placenta is crucial for healthy fetal development and placental development is altered in pregnancy when the fetus has CHD. This study utilized advanced combined diffusion-relaxation MRI and a data-driven analysis technique to test the hypothesis that placental microstructure and perfusion are altered in CHD-affected pregnancies. 48 participants (36 controls, 12 CHD) underwent 67 MRI scans (50 control, 17 CHD). Significant differences in the weighting of two independent placental and uterine-wall tissue components were identified between the CHD and control groups (both pFDR<0.001), with changes most evident after 30 weeks gestation. A Significant trend over gestation in weighting for a third independent tissue component was also observed in the CHD cohort (R = 0.50, pFDR=0.04), but not in controls. These findings add to existing evidence that placental development is altered in CHD. The results may reflect alterations in placental perfusion or the changes in fetal-placental flow, villous structure and maturation that occur in CHD. Further research is needed to validate and better understand these findings and to understand the relationship between placental development, CHD, and its neurodevelopmental implications.

IGF2BP2 regulates the proliferation and migration of endometrial stromal cells through the PI3K/AKT/mTOR signaling pathway in Hu sheep

Insulin-like growth factor 2 mRNA binding protein 2 (IGF2BP2), a significant member of the conserved RNA-binding protein family, plays various roles in numerous physiological and pathological processes. However, the specific function of IGF2BP2 in regulating endometrial function in sheep remains largely unknown. In this study, we observed a significant upregulation in IGF2BP2 mRNA abundance in the endometrium during the luteal phase compared to the follicular phase in Hu sheep. The knockdown of IGF2BP2 resulted in accelerated cell proliferation and migration of Hu sheep endometrial stromal cells (ESCs). Moreover, RNA sequencing analysis revealed that genes with significantly altered expression in IGF2BP2 knockdown cells were predominantly enriched in endometrial receptivity-related signaling pathways, such as cytokine-cytokine receptor interaction, NOD-like receptor, PI3K-AKT, and JAK-STAT signaling pathway. Additionally, the knockdown of IGF2BP2 significantly increased the expression of matrix metalloprotein 9 (MMP9), vascular endothelial growth factor, and prolactin (PRL) in ESCs. The knockdown of IGF2BP2 was also observed to stimulate the PI3K/AKT/mTOR pathway by upregulating integrin β4 (ITGB4) expression. Notably, the downregulation of ITGB4 attenuates IGF2BP2 knockdown-induced facilitation of proliferation and migration of Hu sheep ESCs by inhibiting the PI3K/AKT/mTOR pathway. Collectively, these findings highlight the important role of IGF2BP2 in regulating endometrial function, particularly through the modulation of ESC proliferation and migration via the PI3K/AKT/mTOR pathway.

Flow in fetoplacental-like microvessels in vitro enhances perfusion, barrier function, and matrix stability

Proper placental vascularization is vital for pregnancy outcomes, but assessing it with animal models and human explants has limitations. We introduce a 3D in vitro model of human placenta terminal villi including fetal mesenchyme and vascular endothelium. By coculturing HUVEC, placental fibroblasts, and pericytes in a macrofluidic chip with a flow reservoir, we generate fully perfusable fetal microvessels. Pressure-driven flow facilitates microvessel growth and remodeling, resulting in early formation of interconnected and lasting placental-like vascular networks. Computational fluid dynamics simulations predict shear forces, which increase microtissue stiffness, decrease diffusivity, and enhance barrier function as shear stress rises. Mass spectrometry analysis reveals enhanced protein expression with flow, including matrix stability regulators, proteins associated with actin dynamics, and cytoskeleton organization. Our model provides a powerful tool for deducing complex in vivo parameters, such as shear stress on developing vascularized placental tissue, and holds promise for unraveling gestational disorders related to the vasculature.

Placental microRNAs relate to early childhood growth trajectories

BACKGROUND

Poor placental function is a common cause of intrauterine growth restriction, which in turn is associated with increased risks of adverse health outcomes. Our prior work suggests that birthweight and childhood obesity-associated genetic variants functionally impact placental function and that placental microRNA are associated with birthweight. To address the influence of the placenta beyond birth, we assessed the relationship between placental microRNAs and early childhood growth.

METHODS

Using the SITAR package, we generated two parameters that describe individual weight trajectories of children (0-5 years) in the New Hampshire Birth Cohort Study (NHBCS, n = 238). Using negative binomial generalized linear models, we identified placental microRNAs that relate to growth parameters (FDR < 0.1), while accounting for sex, gestational age at birth, and maternal parity.

RESULTS

Genes targeted by the six growth trajectory-associated microRNAs are enriched (FDR < 0.05) in growth factor signaling (TGF/beta: miR-876; EGF/R: miR-155, Let-7c; FGF/R: miR-155; IGF/R: Let-7c, miR-155), calmodulin signaling (miR-216a), and NOTCH signaling (miR-629).

CONCLUSIONS

Growth-trajectory microRNAs target pathways affecting placental proliferation, differentiation and function. Our results suggest a role for microRNAs in regulating placental cellular dynamics and supports the Developmental Origins of Health and Disease hypothesis that fetal environment can have impacts beyond birth.

IMPACT

We found that growth trajectory associated placenta microRNAs target genes involved in signaling pathways central to the formation, maintenance and function of placenta; suggesting that placental cellular dynamics remain critical to infant growth to term and are under the control of microRNAs. Our results contribute to the existing body of research suggesting that the placenta plays a key role in programming health in the offspring. This is the first study to relate molecular patterns in placenta, specifically microRNAs, to early childhood growth trajectory.

Modeling human ectopic pregnancies with trophoblast and vascular organoids

Ruptured ectopic pregnancy (REP), a pregnancy complication caused by aberrant implantation, deep invasion, and overgrowth of embryos in fallopian tubes, could lead to rupture of fallopian tubes and accounts for 4%-10% of pregnancy-related deaths. The lack of ectopic pregnancy phenotypes in rodents hampers our understanding of its pathological mechanisms. Here, we employed cell culture and organoid models to investigate the crosstalk between human trophoblast development and intravillous vascularization in the REP condition. Compared with abortive ectopic pregnancy (AEP), the size of REP placental villi and the depth of trophoblast invasion are correlated with the extent of intravillous vascularization. We identified a key pro-angiogenic factor secreted by trophoblasts, WNT2B, that promotes villous vasculogenesis, angiogenesis, and vascular network expansion in the REP condition. Our results reveal the important role of WNT-mediated angiogenesis and an organoid co-culture model for investigating intricate communications between trophoblasts and endothelial/endothelial progenitor cells.

Mechanistic insights into the development of severe fetal growth restriction

Fetal growth restriction (FGR), which most commonly results from suboptimal placental function, substantially increases risks for adverse perinatal and long-term outcomes. The only "treatment" that exists is delivery, which averts stillbirth but does not improve outcomes in survivors. Furthermore, the potential long-term consequences of FGR to the fetus, including cardiometabolic disorders, predispose these individuals to developing FGR in their future pregnancies. This creates a multi-generational cascade of adverse effects stemming from a single dysfunctional placenta, and understanding the mechanisms underlying placental-mediated FGR is critically important if we are to improve outcomes and overall health. The mechanisms behind FGR remain unknown. However, placental insufficiency derived from maldevelopment of the placental vascular systems is the most common etiology. To highlight important mechanistic interactions within the placenta, we focus on placental vascular development in the setting of FGR. We delve into fetoplacental angiogenesis, a robust and ongoing process in normal pregnancies that is impaired in severe FGR. We review cellular models of FGR, with special attention to fetoplacental angiogenesis, and we highlight novel integrin-extracellular matrix interactions that regulate placental angiogenesis in severe FGR. In total, this review focuses on key developmental processes, with specific focus on the human placenta, an underexplored area of research.

Definition and Quantification of Three-Dimensional Imaging Targets to Phenotype Pre-Eclampsia Subtypes: An Exploratory Study

Pre-eclampsia is a severe placenta-related complication of pregnancy with limited early diagnostic and therapeutic options. Aetiological knowledge is controversial, and there is no universal consensus on what constitutes the early and late phenotypes of pre-eclampsia. Phenotyping of native placental three-dimensional (3D) morphology offers a novel approach to improve our understanding of the structural placental abnormalities in pre-eclampsia. Healthy and pre-eclamptic placental tissues were imaged with multiphoton microscopy (MPM). Imaging based on inherent signal (collagen, and cytoplasm) and fluorescent staining (nuclei, and blood vessels) enabled the visualization of placental villous tissue with subcellular resolution. Images were analysed with a combination of open source (FIJI, VMTK, Stardist, MATLAB, DBSCAN), and commercially (MATLAB) available software. Trophoblast organization, 3D-villous tree structure, syncytial knots, fibrosis, and 3D-vascular networks were identified as quantifiable imaging targets. Preliminary data indicate increased syncytial knot density with characteristic elongated shape, higher occurrence of paddle-like villous sprouts, abnormal villous volume-to-surface ratio, and decreased vascular density in pre-eclampsia compared to control placentas. The preliminary data presented indicate the potential of quantifying 3D microscopic images for identifying different morphological features and phenotyping pre-eclampsia in placental villous tissue.

Placental delayed villous maturation is associated with fetal congenital heart disease

BACKGROUND

The placenta is crucial for the overall development and lifelong health of the fetus. Abnormal placental development and function occur in pregnancies with fetal congenital heart disease. However, studies that use standardized diagnostic criteria and incorporate control populations are lacking. This limits the generalizability of current research and the ability to determine the specific placental abnormalities associated with congenital heart disease.

OBJECTIVE

This study applied consensus statement guidelines (known as the Amsterdam criteria) for placental pathology interpretation to compare the frequency and pattern of abnormalities in pregnancies with fetal congenital heart disease to demographically matched control pregnancies and evaluate for differences in placental abnormalities by cardiac physiology.

STUDY DESIGN

A single-center retrospective cohort study was conducted from January 2013 to June 2019. Infants with a prenatal diagnosis of moderate-severe congenital heart disease who were born at ≥37 weeks of gestation were included. A control group born at ≥37 weeks of gestation but without fetal congenital heart disease or other major pregnancy complications was matched to the congenital heart disease group on maternal race and ethnicity and infant sex. Using the Amsterdam criteria, placental pathology findings were categorized as delayed villous maturation, maternal vascular malperfusion, fetal vascular malperfusion, and inflammatory lesions. The frequency of placental abnormalities was compared between groups, and logistic regression was performed to evaluate the association of clinical and sociodemographic factors with delayed villous maturation, maternal vascular malperfusion, and fetal vascular malperfusion.

RESULTS

There were 194 pregnancies with fetal congenital heart disease and 105 controls included, of whom 83% in the congenital heart disease group and 82% in the control group were of non-Hispanic White race and ethnicity. Compared with controls, pregnancies with fetal congenital heart disease had higher rates of delayed villous maturation (6% vs 19%; P<.001) and maternal vascular malperfusion (19% vs 34%; P=.007) but not fetal vascular malperfusion (6% vs 10%; P=.23). Infants with congenital heart disease with 2-ventricle anatomy displayed the highest odds of delayed villous maturation compared with controls (odds ratio, 5.5; 95% confidence interval, 2.2-15.7; P<.01). Maternal vascular malperfusion was 2.2 times higher (P=.02) for infants with 2-ventricle anatomy and 2.9 times higher (P=.02) for infants with single-ventricle physiology with pulmonic obstruction. Within the congenital heart disease group, delayed villous maturation was associated with higher maternal body mass index, polyhydramnios, larger infant birth head circumference, and infant respiratory support in the delivery room, whereas maternal vascular malperfusion was associated with oligohydramnios. In multivariable models adjusting for cardiac diagnosis, associations of delayed villous maturation persisted for infant birth head circumference (odds ratio, 1.2; 95% confidence interval, 1.0-1.5; P=.02) and infant respiratory support in the delivery room (odds ratio, 3.0; 95% confidence interval, 1.3-6.5; P=.007).

CONCLUSION

Pregnancies with fetal congenital heart disease displayed higher rates of delayed villous maturation and maternal vascular malperfusion than controls, suggesting that placental maldevelopment may relate to maternal factors. Future investigations are needed to determine the association of these abnormalities with postnatal infant outcomes.

Placental Development and Physiological Changes in Pregnant Ewes in Silvopastoral and Open Pasture Systems during the Summer

This study aimed to analyze the reproductive and physiological changes in ewes subjected to heat stress during pregnancy at UTFPR-Brazil. Twenty-four pregnant crossbred ewes were kept in a silvopastoral system (SP) or an open pasture system (OP) throughout the final trimester of pregnancy. Both systems were stressful, but the SP system had lower air temperature than the OP system (26.0 ± 0.38 and 26.9 ± 0.41 °C, respectively; p = 0.0288). Moreover, the radiant thermal load of the two groups presented a difference of 34 Wm^-2 (p = 0.0288), and the grass temperature was also lower in the SP system compared to that in the OP system (23.4 ± 0.37 and 25.6 ± 0.44 °C, respectively; p = 0.0043). The respiratory and heart rates of animals from the OP group were higher than those from the SP group (p < 0.001), but no difference was observed in the mobilization of white blood cells (p = 0.4777), and the neutrophil count was only affected by time (p < 0.0001). As regards placental biometry, placentas in twin pregnancies had a greater membrane area (p = 0.0223), but no differences between the systems were observed in placental weight (p = 0.1522) and the number of cotyledons (p = 0.5457). We concluded that the type of rearing system used affects the thermal comfort of pregnant ewes, and that an SP system can offer more amenable microclimatic conditions, which result in greater comfort for the ewes.

Deep Semantic Segmentation of Angiogenesis Images

Angiogenesis is the development of new blood vessels from pre-existing ones. It is a complex multifaceted process that is essential for the adequate functioning of human organisms. The investigation of angiogenesis is conducted using various methods. One of the most popular and most serviceable of these methods in vitro is the short-term culture of endothelial cells on Matrigel. However, a significant disadvantage of this method is the manual analysis of a large number of microphotographs. In this regard, it is necessary to develop a technique for automating the annotation of images of capillary-like structures. Despite the increasing use of deep learning in biomedical image analysis, as far as we know, there still has not been a study on the application of this method to angiogenesis images. To the best of our knowledge, this article demonstrates the first tool based on a convolutional Unet++ encoder-decoder architecture for the semantic segmentation of in vitro angiogenesis simulation images followed by the resulting mask postprocessing for data analysis by experts. The first annotated dataset in this field, AngioCells, is also being made publicly available. To create this dataset, participants were recruited into a markup group, an annotation protocol was developed, and an interparticipant agreement study was carried out.

Feto-placental Unit: From Development to Function

The placenta is an intriguing organ that allows us to survive intrauterine life. This essential organ connects both mother and fetus and plays a crucial role in maternal and fetal well-being. This chapter presents an overview of the morphological and functional aspects of human placental development. First, we describe early human placental development and the characterization of the cell types found in the human placenta. Second, the human placenta from the second trimester to the term of gestation is reviewed, focusing on the morphology and specific pathologies that affect the placenta. Finally, we focus on the placenta's primary functions, such as oxygen and nutrient transport, and their importance for placental development.

Allometric scaling relationships in mouse placenta

Fetal growth and maturation are highly intertwined with placental development during pregnancy. Here we used placental vascular morphology measurements (depth and span) as well as the umbilical artery (UA) diameter of previously published studies on three different mouse strains (C57BL6/J, CD-1 and BALB/c), which were exposed to different conditions (combination antiretroviral therapy, chronic maternal hypoxia and malaria infection) at different embryonic days, to test the hypothesis that placental vascularization and specifically the UA size affect conceptus weight. Interaction of each study parameter with embryonic day, strain and exposure to treatments are studied to investigate the stability of the scaling relationships across and/or within strains and conditions. In addition, the effect of UA diameter on the placental growth measurements (depth and span) is studied. These results show that the power-law scaling relationship of conceptus weight and placental depth with the UA diameter is conserved across strains and conditions with the scaling exponent of approximately 3/8 and 5/8, respectively. By contrast, the relationship between conceptus weight and either the placental span or depth is different between strains and conditions, suggesting multiple mechanisms of vascular adaptation.

Role of microRNAs in trophoblast invasion and spiral artery remodeling: Implications for preeclampsia

It is now well-established that microRNAs (miRNAs) are important regulators of gene expression. The role of miRNAs in placental development and trophoblast function is constantly expanding. Trophoblast invasion and their ability to remodel uterine spiral arteries are essential for proper placental development and successful pregnancy outcome. Many miRNAs are reported to be dysregulated in pregnancy complications, especially preeclampsia and they exert various regulatory effects on trophoblasts. In this review, we provide a brief overview of miRNA biogenesis and their mechanism of action, as well as of trophoblasts differentiation, invasion and spiral artery remodeling. We then discuss the role of miRNAs in trophoblasts invasion and spiral artery remodeling, focusing on miRNAs that have been thoroughly investigated, especially using multiple model systems. We also discuss the potential role of miRNAs in the pathogenesis of preeclampsia.

First Trimester of Pregnancy as the Sensitive Period for the Association between Prenatal Mosquito Coil Smoke Exposure and Preterm Birth

Mosquito coils are efficient mosquito repellents and mosquito coil smoke (MCS) contributes to indoor air pollution. However, no prior population-based study has investigated whether prenatal MCS exposure is a risk factor for preterm birth (PTB) and whether exposure to MCS in different trimesters of pregnancy is associated with different levels of risk. The sample involved 66,503 mother-child dyads. Logistic regression models were used to examine the relationships between prenatal MCS exposure during different trimesters of pregnancy and PTB. We found that prenatal MCS exposure was associated with a greater likelihood of PTB (OR = 1.12, 95%CI: 1.05-1.20). The prenatal MCS exposure during the first trimester was associated with 1.17 (95%CI: 1.09-1.25) times the odds of being PTB, which was higher than exposure during the second trimester (OR = 1.11, 95%CI: 1.03-1.19) and during the third trimester (OR = 1.08, 95%CI: 1.01-1.16). In the stratified analysis, prenatal MCS exposure significantly increased PTB risk among girls but not among boys. Our results indicated that maternal MCS exposure during pregnancy was associated with PTB and that the first trimester might be the sensitive period. In light of these findings, public health interventions are needed to reduce prenatal exposure to MCS, particularly during the first trimester of pregnancy.

Critical window for the association between prenatal environmental tobacco smoke exposure and preterm birth

Although environmental tobacco smoke (ETS) exposure is considered to be a severe public health problem and a modifiable risk factor for preterm birth (PTB), we still lack a comprehensive understanding of the PTB risk associated with trimester-specific prenatal ETS exposure. This study aimed to examine the accumulation of risk across trimester ETS exposure and the critical window of the association between maternal ETS exposure during pregnancy and PTB. A total of 63,038 mother-child pairs were involved in the analysis of the 2017 survey of Longhua Child Cohort Study. Information about socio-demographic characteristics, prenatal ETS exposure, and birth outcomes were collected using a self-report questionnaire. A series of logistic regression models were employed to assess the associations between prenatal ETS exposure and PTB. We found that maternal ETS exposure during pregnancy significantly increased the risk of PTB and this association increased with both the average level of daily ETS exposure and the number of trimesters of ETS exposure. Moreover, mothers who were initially exposed to ETS in the 1st trimester of pregnancy had significant higher risk of PTB (OR = 1.34, 95% CI: 1.25-1.44). Furthermore, mothers exposed to ETS in the 1st trimester only (OR = 1.26, 95%CI: 1.04-1.50), in both 1st and 2nd trimester (OR = 1.35, 95%CI: 1.08-1.67) and throughout pregnancy (OR = 1.35, 95%CI: 1.24-1.46) experienced a significantly high risk of PTB. Prenatal maternal ETS exposure during only the 2nd trimester also resulted in a high risk of PTB with marginal significance (OR = 1.33, 95% CI:0.78-2.13). To conclude, the 1st and early 2nd trimester might be the critical window for prenatal ETS exposure causing PTB.

Placental angiogenesis, IUGR & CMV awareness in Iraqi women

The placenta is considered the first interface between mother and fetus, and a normal placenta is essential for pregnancy without complications. IUGR is considered the most common condition recognized in complicated pregnancy and accounts for 26% or more of stillbirth. The current study aims to explore the presence of IUGR and placental angiogenesis by investigating the expression of VEGF and eNOS in both placenta of IUGR of CMV-infected mother and placenta of normal mother in relation to awareness of CMV in Iraqi women.

The expressions of VEGF and e NOS was studied using the avidin-biotin-peroxidase technique, while awareness was studied using 10-minute surveys in Al-Karkh directorate (Baghdad) to investigate their knowledge of CMV infection in relation to the level of education and economic status.

The expression of angiogenic factors (VEGF, eNOS) was significant in syncitiotrophoblasts, smooth muscle cells and corionic villous stromal cells, and was significant in unaware, low-educated women with low income. Increased expression of angiogenic factors of IUGR babies may be a result of unawareness of CMV infection, which leads to dysregulation of angiogenic factors, and, subsequently, to inadequate placental vascularization.

Organ-specific endothelial cell heterogenicity and its impact on regenerative medicine and biomedical engineering applications

Endothelial cells (ECs) are a key cellular component of the vascular system as they form the inner lining of the blood vessels. Recent findings highlight that ECs express extensive phenotypic heterogenicity when following the vascular tree from the major vasculature down to the organ capillaries. However, in vitro models, used for drug development and testing, or to study the role of ECs in health and disease, rarely acknowledge this EC heterogenicity. In this review, we highlight the main differences between different EC types, briefly summarize their different characteristics and focus on the use of ECs in in vitro models. We introduce different approaches on how ECs can be utilized in co-culture test systems in the field of brain, pancreas, and liver research to study the role of the endothelium in health and disease. Finally, we discuss potential improvements to current state-of-the-art in vitro models and future directions.

The role of the placenta in spontaneous preterm labor and delivery with intact membranes

OBJECTIVES

To determine whether placental vascular pathology and impaired placental exchange due to maturational defects are involved in the etiology of spontaneous preterm labor and delivery in cases without histologic acute chorioamnionitis.

METHODS

This was a retrospective, observational study. Cases included pregnancies that resulted in spontaneous preterm labor and delivery (<37 weeks), whereas uncomplicated pregnancies that delivered fetuses at term (≥37-42 weeks of gestation) were selected as controls. Placental histological diagnoses were classified into three groups: lesions of maternal vascular malperfusion, lesions of fetal vascular malperfusion, and placental microvasculopathy, and the frequency of each type of lesion in cases and controls was compared. Moreover, we specifically searched for villous maturational abnormalities in cases and controls. Doppler velocimetry of the umbilical and uterine arteries were performed in a subset of patients.

RESULTS

There were 184 cases and 2471 controls, of which 95 and 1178 had Doppler studies, respectively. The frequency of lesions of maternal vascular malperfusion was greater in the placentas of patients with preterm labor than in the control group [14.1% (26/184) vs. 8.8% (217/2471) (p=0.023)]. Disorders of villous maturation were more frequent in the group with preterm labor than in the control group: 41.1% (39/95) [delayed villous maturation in 31.6% (30/95) vs. 2.5% (13/519) in controls and accelerated villous maturation in 9.5% (9/95) vs. none in controls].

CONCLUSIONS

Maturational defects of placental villi were associated with approximately 41% of cases of unexplained spontaneous preterm labor and delivery without acute inflammatory lesions of the placenta and with delivery of appropriate-for-gestational-age fetuses.

Analysis of commonly expressed genes between first trimester fetal heart and placenta cell types in the context of congenital heart disease

Congenital heart disease (CHD) is often associated with fetal growth abnormalities. During the first trimester of pregnancy, the heart and placenta develop concurrently, and share key developmental pathways. It is hypothesized that defective morphogenesis of either organ is synergistically linked. However, many studies determined to understand the mechanisms behind CHD overlook the contribution of the placenta. In this study, we aimed to identify commonly expressed genes between first trimester heart and placenta cells using two publicly available single cell sequencing databases. Using a systematic computational approach, we identified 328 commonly expressed genes between heart and placenta endothelial cells and enrichment in pathways including Vasculature Development (GO:0001944, FDR 2.90E−30), and Angiogenesis (GO:0001525, FDR 1.18E−27). We also found, in comparison with fetal heart endothelial cells, 197 commonly expressed genes with placenta extravillous trophoblasts, 128 with cytotrophoblasts and 80 with syncytiotrophoblasts, and included genes such as FLT1, GATA2, ENG and CDH5. Finally, comparison of first trimester cardiomyocytes and placenta cytotrophoblasts revealed 53 commonly expressed genes and enrichment in biological processes integral to cellular function including Cellular Respiration (GO:0045333; FDR 5.05E−08), Ion Transport (GO:0006811; FDR 2.08E−02), and Oxidation–Reduction Process (GO:0055114; FDR 1.58E−07). Overall, our results identify specific genes and cellular pathways common between first trimester fetal heart and placenta cells which if disrupted may concurrently contribute to the developmental perturbations resulting in CHD.

The endocannabinoids anandamide and 2-arachidonoylglycerol modulate the expression of angiogenic factors on HTR8/SVneo placental cells

The interest on the endocannabinoid system (ECS) in human reproduction has grown due to its involvement in placenta development, which led to growing concerns over pregnant cannabis consumer's impact on pregnancy outcome. The endocannabinoids anandamide (AEA) and 2-arachidonoylglycerol (2-AG) modulate placental trophoblast proliferation and apoptosis. However, their role on other placentation events such as angiogenesis and invasion are unknown. Using the human extravillous trophoblast HTR-8/SVneo cells, a well-accepted model of first trimester extravillous trophoblast (EVT), this study aims to investigate whether AEA and 2-AG can modulate the expression of angiogenesis- and invasion-related factors. Transcript analysis of angiogenic factors of the vascular endothelial growth factor (VEGF) and matrix metalloproteinase (MMP) protein family demonstrated the ability of AEA to increase VEGF-C and VEGFR3 expression via cannabinoid receptors CB1 and CB2 while the placental growth factor (PlGF) was increased through CB1. Moreover, an increase in VEGFR1, sFLT1, VEGFR2, MMP-2 and TIMP-1 independent of cannabinoid receptor activation was verified. However, 2-AG only increased PlGF transcript through CB1/CB2 activation. Both endocannabinoids stimulated HTR8/SVneo endothelial-like tube formation. As for the wound healing assay, only 2-AG was able to increase the percentage of wound closure. Moreover, the data demonstrated that both AEA and 2-AG, via cannabinoid receptors, activated the STAT3 signaling pathway. Distinct effects were observed on transcription factor HIF-1α and AKT phosphorylation that decreased with both endocannabinoids. Although different angiogenic and migration factors are affected the results obtained in this work showcase once more the ability of the endocannabinoids to modulate key processes in placental physiology.

The Role of Cytokines in Maintaining the Dynamics of Cell-Cell Interaction between Natural Killer Cells and Trophoblast Cells

We analyzed the effect of individual cytokines that are secretory products of placenta typical of the uteroplacental bed. The proinflammatory cytokines IL-6, IFNγ, and IL-1β increased the expression of TGFβR2 molecule by trophoblast cells, while VEGF and PLGF increased the expression of CD45, CD29, and CD54 adhesion molecule by trophoblast cells. The antiinflammatory cytokine IL-4 increased LeptinR expression by trophoblast cells. PMA and TNFα also enhanced the adhesion of NK cells to trophoblast cells. Our findings suggest that NK cells involved CD11a, CD11b, and CD18 molecules during their transmigration through trophoblast, as well as during their transendothelial migration.

Human Decidual Mesenchymal Stem Cells Obtained From Early Pregnancy Improve Cardiac Revascularization Postinfarction by Activating Ornithine Metabolism

Background

Compared with bone marrow mesenchymal stem cells (BMSCs), decidual mesenchymal stem cells (DMSCs) are easy to obtain and exhibit excellent angiogenic effects, but their role in cell transplantation after myocardial infarction (MI) remains unclear.

Methods

BMSCs and DMSCs were harvested from healthy donors. The effects of both cell types on angiogenesis were observed in vitro. Metabonomics analysis was performed to compare different metabolites and screen critical metabolic pathways. A murine model of acute myocardial infarction (AMI) was established, which was randomized into five groups (control, BMSC, DMSC, DMSC + ODCshRNA and BMSC + ODC consisting of 50 animals, equally divided into each group). The therapeutic effect of DMSCs on MI in rats was assessed based on neovascularization and cardiac remodeling.

Results

DMSCs exhibited a better angiogenic effect on human umbilical vein endothelial cells (HUVECs) than BMSCs in vitro. In addition, ornithine metabolism, which is associated with vascularization, was significantly increased in DMSCs. The transplantation of DMSCs in the rat MI model significantly enhanced angiogenesis of the infarct border area and improved cardiac remodeling and dysfunction postinfarction compared with BMSCs. Furthermore, inhibition of ornithine metabolism by silencing ornithine decarboxylase (ODC) in DMSCs partly abolished the benefits of DMSC transplantation.

Conclusion

Compared with BMSCs, DMSCs exhibited better efficacy in improving revascularization and heart remodeling post-MI via the activation of ODC-associated ornithine metabolism.

Cardiac dysfunction and remodeling regulated by anti-angiogenic environment in patients with preeclampsia: the ANGIOCOR prospective cohort study protocol

Background

Cardiovascular diseases (CVD) are cause of increased morbidity and mortality in spite of advances for diagnosis and treatment. Changes during pregnancy affect importantly the maternal CV system. Pregnant women that develop preeclampsia (PE) have higher risk (up to 4 times) of clinical CVD in the short- and long-term. Predominance of an anti-angiogenic environment during pregnancy is known as main cause of PE, but its relationship with CV complications is still under research. We hypothesize that angiogenic factors are associated to maternal cardiac dysfunction/remodeling and that these may be detected by new cardiac biomarkers and maternal echocardiography.

Methods

Prospective cohort study of pregnant women with high-risk of PE in first trimester screening, established diagnosis of PE during gestation, and healthy pregnant women (total intended sample size n = 440). Placental biochemical and biophysical cardiovascular markers will be assessed in the first and third trimesters of pregnancy, along with maternal echocardiographic parameters. Fetal cardiac function at third trimester of pregnancy will be also evaluated and correlated with maternal variables. Maternal cardiac function assessment will be determined 12 months after delivery, and correlation with CV and PE risk variables obtained during pregnancy will be evaluated.

Discussion

The study will contribute to characterize the relationship between anti-angiogenic environment and maternal CV dysfunction/remodeling, during and after pregnancy, as well as its impact on future CVD risk in patients with PE. The ultimate goal is to improve CV health of women with high-risk or previous PE, and thus, reduce the burden of the disease.

Trial registration

NCT04162236

Placental and fetal characteristics of the Ohia mouse line recapitulate outcomes in human hypoplastic left heart syndrome

Congenital heart defects (CHDs) are the most common birth defect worldwide. The morbidity and mortality associated with these defects is compounded by increased frequency of fetal growth abnormalities. In the Ohia mouse model of hypoplastic left heart syndrome (HLHS), the double homozygous genotype is embryonically lethal at mid-pregnancy; a time in which optimal establishment of the placenta is crucial to fetal survival. We aimed to characterize placental and fetal growth and development in the double heterozygous genotype (Sap130^m/+Pcdha9^m/+). There was a shift in frequency of fetuses with reduced weight near term in the Sap130^m/+Pcdha9^m/+ fetuses compared to wildtype, driven by lower fetal weight in male fetuses compared to female. This shift in fetal weight distribution in the Sap130^m/+Pcdha9^m/+ fetuses was associated with reduced labyrinth region area (P < 0.001) and reduced fetal capillary density (P < 0.001) in the placentas, the latter being significantly lower in male Sap130^m/+Pcdha9^m/+ placentas compared to female. mRNA expression of several nutrient transporters was also lower in placentas from males compared to placentas from females, irrespective of genotype. Overall, this data shows that whilst the double heterozygous fetuses do not carry heart defects, placental development and function is impaired, particularly in males. Such differences are similar to findings in studies of human placentas and highlights the importance of this mouse model in continuing to understand the developmental links and disruptions to the heart-placenta axis.

Angiogenic factors measured in aspirated placental tissue between the 10 + 6 and 18 + 3 weeks of gestation

This study was designed to determine the level of vascular endothelial growth factor-A (VEGF-A), basic fibroblast growth factor (bFGF) and endothelial nitric oxide synthase (eNOS) in chorionic villi during in first and second trimester, and their association with nuchal translucency (NT) measured by ultrasound. Seventy-five singleton healthy pregnancies with no detected congenital malformation were collected for NT measurements and chorionic villus sampling (CVS). Concentrations of angiogenic factors were assayed in chorionic villi sampled between 10 + 6 and 18 + 3 weeks of gestation. ENOS level was steady during this gestational period, while the concentrations of VEGF-A and bFGF significantly decreased. Placental concentrations of VEGF-A and bFGF correlated positively with each other (semi-partial correlation in multivariable linear regression (r): 0.90) and both correlated negatively with the eNOS level (r: -0.64 and r: -0.83, respectively). NT was positively correlated with eNOS concentration and negatively correlated with bFGF levels (r: 0.85 and r: -0.78, respectively). Inverse correlation was found between gestational age and VEGF-A and bFGF concentrations (r: -0.57 and r: 0.73, respectively). Alterations of angiogenic factors in chorionic villi might be an adjunct modality to NT and foetal growth as sonographic markers.

Effects of palmitic acid and eicosapentaenoic acid on angiogenesis of porcine vascular endothelial cells

Restricted placental angiogenesis is an important cause of intrauterine growth retardation in piglets. During pregnancy, sow obesity can result in an increase in placental lipid deposition, subsequently inhibiting placental angiogenesis and fetal development. However, the effect of different types of fatty acids on placental angiogenesis is still unclear. Trophoblast cells and vascular endothelial cells constitute two important types of placental tissue. In this study, we used palmitic acid (C16:0) and eicosapentaenoic acid (C20:5, n-3), respectively, to treat porcine trophectoderm cells (pTr2) and porcine iliac artery endothelial cells (PIEC) to study the effects of saturated fatty acids and n-3 polyunsaturated fatty acids (PUFAs) on placental angiogenesis in vitro. We found that C16:0 caused significant cytotoxicity in pTr2 and PIEC (p < 0.01) and inhibited the proliferation and migration of PIEC (p < 0.01), whereas C20:5 treatment exhibited very low cytotoxicity and minimal inhibition of cellular proliferation. Meanwhile, a low concentration of C16:0 had no effect on the tube formation in PIEC, whereas C20:5 significantly promoted tube formation of PIEC (p < 0.01). These results suggested that saturated fatty acids and n-3 PUFAs had different effects on placental angiogenesis. As essential functional fatty acid, n-3 PUFA might be effective measure in alleviating the placental lipotoxicity caused by sow obesity during pregnancy.

Inhibition of the C-X-C Motif Chemokine 12 (CXCL12) and Its Receptor CXCR4 Reduces Utero-Placental Expression of the VEGF System and Increases Utero-Placental Autophagy

The placenta, a unique organ that only develops during pregnancy, is essential for nutrient, oxygen, and waste exchange between offspring and mother. Yet, despite its importance, the placenta remains one of the least understood organs and knowledge of early placental formation is particularly limited. Abnormalities in placental development result in placental dysfunction or insufficiency whereby normal placental physiology is impaired. Placental dysfunction is a frequent source of pregnancy loss in livestock, inflicting serious economic impact to producers. Though the underlying causes of placental dysfunction are not well-characterized, initiation of disease is thought to occur during establishment of functional fetal and placental circulation. A comprehensive understanding of the mechanisms controlling placental growth and vascularization is necessary to improve reproductive success in livestock. We propose chemokine C-X-C motif ligand 12 (CXCL12) signaling through its receptor CXCR4 functions as a chief coordinator of vascularization through direct actions on fetal trophoblast and maternal endometrial and immune cells. To investigate CXCL12–CXCR4 signaling on uteroplacental vascular remodeling at the fetal–maternal interface, we utilized a CXCR4 antagonist (AMD3100). On day 12 post-breeding in sheep, osmotic pumps were surgically installed and delivered either AMD3100 or saline into the uterine lumen ipsilateral to the corpus luteum for 14 days. On day 35 of ovine pregnancy, fetal/placental and endometrial tissues were collected, snap-frozen in liquid nitrogen, and uterine horn cross sections were preserved for immunofluorescent analysis. Suppressing CXCL12–CXCR4 at the fetal–maternal interface during initial placental vascularization resulted in diminished abundance of select angiogenic factors in fetal and maternal placenta on day 35. Compared to control, less vascular endothelial growth factor (VEGF) and VEFG receptor 2 (KDR) were observed in endometrium when CXCL12–CXCR4 was diminished. Less VEGF was also evident in fetal placenta (cotyledons) in ewes receiving AMD3100 infusion compared to control. Suppressing CXCL12–CXCR4 at the fetal–maternal interface also resulted in greater autophagy induction in fetal and maternal placenta compared to control, suggestive of CXCL12–CXCR4 impacting cell survival. CXCL12–CXCR4 signaling may govern placental homeostasis by serving as a critical upstream mediator of vascularization and cell viability, thereby ensuring appropriate placental development.

Flow-through isolation of human first trimester umbilical cord endothelial cells

Human umbilical vein and artery endothelial cells (HUVEC; HUAEC), placental endothelial cells (fpAEC), and endothelial colony-forming cells (ECFC) from cord blood are a widely used model for researching placental vascular development, fetal and placental endothelial function, and the effect of adverse conditions in pregnancy thereon. However, placental vascular development and angiogenesis start in the first weeks of gestation, and adverse conditions in pregnancy may also affect endothelial function before term, suggesting that endothelial cells from early pregnancy may respond differently. Thus, we established a novel, gentle flow-through method to isolate pure human umbilical endothelial cells from first trimester (FTUEC). FTUEC were characterized and their phenotype was compared to the umbilical endothelium in situ as well as to other fetal endothelial cell models from term of gestation, i.e. HUVEC, fpAEC, ECFC. FTUEC possess a CD34-positive, juvenile endothelial phenotype, and can be expanded and passaged. We regard FTUEC as a valuable tool to study developmental processes as well as the effect of adverse insults in pregnancy in vitro.

Determination of Urine Protein Levels and Analysis of Differences in Vascular Endothelial Growth Factor Levels between Early Onset and Late Onset Preeclampsia

BACKGROUND: Preeclampsia is a disease with the high mortality rate. Data indicate that 23.5% of maternal deaths due to preeclampsia. Urine protein testing is essential for pregnant women to discover the function of kidney during pregnancy and to identify the presence of preeclampsia, both mild and severe, which it can lead to eclampsia. Preeclampsia based on onset can also be detected by examining serum biomarkers of Vascular Endothelial Growth Factor (VEGF). AIM: The aim of this study was to overview the urine protein levels and analyzed the differences serum VEGF levels between the early and late onset of preeclampsia. MATERIALS AND METHODS: This study used design of the cross sectional comparative study in RSUP DR. M Djamil Padang, Pariaman Hospital, Aisiyah Pariaman Hospital, and Padang Pariaman Regional Hospital for 2 years. The population in this study consisted of patients with early and late onset preeclampsia who went to the study site during that time and met the inclusion criteria. Sampling with consecutive sampling consisted of 28 people per group. RESULTS: The results revealed that the number of patients who had urine protein levels with a value of 2+ at the early onset was 14 and at the late onset was 12, meanwhile for patients with a urine protein content value of 3+ at the early onset it was 14 and at the late onset was 10.For the category urine protein with a value of 4+ amounted to 6 people only in the late onset group. The results of the normality test showed that the mean value of VEGF levels at early onset and late onset was 3.91 pg / ml and 4.3 pg / ml, respectively. Thus, the level of VEGF serum had an abnormal distribution and it led to the T test data could not be tested. So then, the testing was done using a non-parametric test, namely the Mann-Whittney test. The mean levels of VEGF, respectively, based on the Mann-Whittney test for early onset preeclampsia and late onset preeclampsia were 29.75 ng / mL and 30.25 ng / mL. VEGF in early onset preeclampsia is lower than late onset preeclampsia. CONCLUSION: Based on the results obtained, it can be concluded that there was no significant difference in the level of VEGF in early onset preeclampsia and late onset preeclampsia (p = 0.42). Keywords: Preeclampsia, early onset, late onset, urine protein, VEGF

Characteristics of Natural Killer Cell Interaction with Trophoblast Cells During Pregnancy

BACKGROUND

Maternal natural killer cells (NK cells) are a prevailing leukocyte population in the uteroplacental bed. Current descriptions of the effect of cytokines from the placental microenvironment on the expression of receptors by trophoblast and NK cells are inadequate and contradictory. There is insufficient information about the ability of NK cells to migrate through trophoblast cells.

OBJECTIVE

To assess the impact of conditioned media obtained during culturing of placentas from the first and the third trimesters of healthy pregnancies on the phenotype of trophoblast and NK cells and impact on adhesion and transmigration of NK cells through trophoblast cell layer.

RESULTS

We established that conditioned media obtained from both first and third trimester placentas increased the intensity of CD106, CD49e, CD49a, CD31, CD51/61, and integrin β6 expression by trophoblast cells. Conditioned media obtained from first trimester placentas increased the intensity of CD11a, CD29, CD49d, CD58, CD29 expression by NK cells. The presence of conditioned media from third trimester placentas resulted in more intense CD29, CD49d, CD11a, CD29, CD49d, and CD58 expression by NK cells. Migration of NK cells through trophoblast cells in the presence of conditioned media from first trimester placentas was increased compared with the migration level in the presence of conditioned media from third trimester placentas. This may be associated with increased expression of CD18 by NK cells.

CONCLUSION

First trimester placental secretory products increase adhesion receptor expression by both trophoblast and NK cells. Under these conditions, trophoblast is capable of ensuring NK cell adhesion and transmigration.

Mesenchymal Stem/Stromal Cells from the Placentae of Growth Restricted Pregnancies Are Poor Stimulators of Angiogenesis

The extensively branched vascular network within the placenta is vital for materno-fetal exchange, and inadequate development of this network is implicated in the pregnancy disorder fetal growth restriction (FGR), where babies are born pathologically small. Placental mesenchymal stem/stromal cells (pMSCs) and placental macrophages both reside in close proximity to blood vessels within the placenta, where they are thought to promote angiogenesis via paracrine mechanisms. However, the relationship between pMSCs, macrophages and placental vascular development has not yet been examined. We aimed to determine if inadequate paracrine stimulation of placental vascular development by pMSCs and macrophages during pregnancy may contribute to the inadequate vascularisation seen in FGR. Media conditioned by MSCs from FGR placentae significantly inhibited endothelial tube formation, compared to conditioned media derived from normal pMSCs. Similarly, macrophages exposed to media conditioned by FGR pMSCs were less able to stimulate endothelial tube formation in comparison to macrophages exposed to media conditioned by normal pMSCs. While MSCs from normal placentae produce a combination of angiogenic and anti-angiogenic cytokines, there were no significant differences in the secretion of the anti-angiogenic cytokines thrombospondin-1, insulin growth factor binding protein-4, or decorin between normal and FGR pMSCs that could explain how FGR pMSCs inhibited endothelial tube formation. Together, these data suggest a dysregulation in the secretion of paracrine factors by pMSCs in FGR placentae. These findings illustrate how cross talk between pro-angiogenic cell types in the placenta may be crucial for adequate angiogenesis.

Individual exposure to urban air pollution and its correlation with placental angiogenic markers in the first trimester of pregnancy, in São Paulo, Brazil

Pollution of the atmosphere is known that may lead to adverse obstetric outcomes, including fetal growth restriction, gestational hypertension, and preeclampsia. Such disorders are correlated with imbalances in angiogenic factors, which may also be involved in the pathological mechanism as the pollutants impact placental and maternal physiology. In the first trimester of gestation, this study assessed the outcomes of personal maternal short period exposure to air pollution on soluble fms-like tyrosine kinase 1 (sFlt1) and placental growth factor (PLGF) of pregnant women blood concentrations. This was a cross-sectional study, held in the city of São Paulo, Brazil, and conducted with low-risk pregnant women, who carried personal passive nitrogen dioxide (NO2) and ozone (O3) monitors for about a few days preceding the ultrasound evaluation, and on this day, the venous blood sample was collected to measure the angiogenic factors sFlt1 and PLGF and their ratio (sFlt1/PLGF) by enzyme-linked immunosorbent assay (ELISA). By means of multiple regression models, the effect of the studied pollutants on the log-transformed concentrations of the angiogenic factors was evaluated. One hundred thirty-one patients were included. The log of the sFlt1/PLGF ratio increased with rising NO2 levels (p = 0.021 and beta = 0.206), and the log of the PLGF concentration showed a negative correlation with NO2 (p = 0.008 and beta = - 0.234). NO2, an indicator of the levels of primary air pollutants, presented significant positive correlation with an increased sFlt1/PLGF ratio and diminished PLGF levels, which may reflect an antiangiogenic state generated by air pollution exposure.

The role of mediating factors involved in angiogenesis during implantation

Angiogenesis is a critical component of normal implantation and placentation and underlines the importance of vascularization in early pregnancy. Differentiated expression of angiogenesis factors in different decision tissues during different stages of implantation, indicates their involvement in the regulation of vascular remodeling and angiogenesis. Disorders in vascular development may play a role in the pathogenesis of recurrent abortions. The success of implantation, placentation and subsequent pregnancy evolution requires coordination of vascular development and adaptations at both sides of the maternal–fetal interface. The human implantation process is a continuous process, which begins with the apposition and attachment of the blastocyst to the apical surface of the luminal endometrial epithelium and continues throughout the first trimester of pregnancy until the extravillous trophoblast invades and remodels maternal vascularization. Numerous regulatory molecules play functional roles in many processes, including preparation of the endometrial stroma (decidualization), epithelium for implantation, control of trophoblastic adhesion and invasion. These regulatory molecules include cytokines, chemokines, and proteases, many of which are expressed by different cell types, having slightly different functions as the implant progresses

Twin-twin transfusion syndrome is associated with alterations in the metabolic profile of maternal plasma in early gestation: a pilot study

OBJECTIVE

Twin-twin transfusion syndrome (TTTS) causes perinatal mortality and morbidity in monochorionic twins. The early recognition of and interventional therapy for TTTS is associated with a more favorable overall prognosis. However, the prediction by the use of ultrasound in the first trimester has relatively poor sensitivity and specificity. This study aimed to identify metabolic biomarkers to aid in ultrasound screening of TTTS.

METHODS

Maternal plasma was prospectively collected between 11 and 15 weeks of gestation in apparently uncomplicated monochorionic-diamniotic twin pregnancies. This cohort was divided into: (i) patients who were subsequently diagnosed with TTTS by using ultrasound; (ii) uncomplicated matched controls. Metabolome was profiled by using gas chromatography-mass spectrometry.

RESULTS

The levels of fatty acids, organic acids, oxaloacetic acid, and beta-alanine were significantly lower in the TTTS maternal plasma at 11-15 weeks of gestation, and methionine and glycine were also higher (p < 0.05, FDR<0.12). Generally, in TTTS pregnancies, the metabolisms of amino acid, carbohydrate, cofactors, vitamins, and purine were "down-regulated"; whereas bile secretion and pyrimidine metabolism were "upregulated."

CONCLUSIONS

The metabolomics scanning of early gestation maternal plasma may identify those pregnancies that subsequently develop TTTS; in particular, downregulated fatty acid levels may be biologically plausible to be implicated in the pathogenesis of TTTS.

Reduced birth weight caused by sextuple drug resistant Plasmodium falciparum infection in early 2nd trimester

Mutations in the Plasmodium falciparum genes Pfdhfr and Pfdhps, particularly the sextuple mutant haplotype threatens the antimalarial effectiveness of sulfadoxine-pyrimethamine as intermittent preventive treatment during pregnancy (IPTp). To explore the impact of sextuple mutant haplotype infections on outcome measures after provision of IPTp-SP, we monitored birth outcomes in women followed from prior to conception or from the first trimester until delivery. Women infected with sextuple haplotypes in early 2 nd trimester specifically, delivered newborns with a lower birth weight (-267g, 95% CI -454; -59, p=0·01) compared to women who did not have malaria during pregnancy and women infected with less SP resistant haplotypes (-461g, 95% CI -877; -44, p=0·03). Thus, sextuple haplotype infections seems to impact the effectiveness of SP for IPTp and directly impact birth outcome by lowering birth weight. Close monitoring and targeted malaria control during early pregnancy is therefore crucial to improve birth outcomes.

Placental and maternal sFlt1/PlGF expression in gestational diabetes mellitus

Gestational diabetes mellitus (GDM) and preeclampsia (PE) are both characterized by endothelial dysfunction and GDM women have higher incidence of PE. The placenta plays a key role in PE pathogenesis but its contribution to PE during GDM remains unclear. Herein, we compared placental and maternal blood anti-angiogenic soluble fms-like tyrosine kinase-1 (sFlt1) and pro-angiogenic Placental Growth Factor (PlGF) expressions in GDM and GDM-PE pregnancies compared to controls (CTRL) and PE cases. Electrochemiluminescence immunoassays showed a significantly higher maternal blood sFlt1/PlGF values in GDM-PE relative to CTRL and GDM pregnancies. We reported that placental PlGF gene expression was significantly decreased in GDM, PE and GDM-PE relative to CTRL. However, PlGF protein levels were significantly increased in GDM and GDM-PE relative to CTRL and PE placentae. Finally, sFlt1 gene expression was significantly increased in PE relative to CTRL, GDM and GDM-PE placentae. In contrast, sFlt1 protein expression was significantly decreased in GDM-PE relative to CTRL, GDM and PE placentae. Finally, higher sFlt1/PlGF ratio in GDM-PE maternal blood suggest that sFlt1 overproduction is related to PE onset also in GDM pregnancies even though characterized by a less severe endothelial dysfunction in terms of angiogenic biomarkers.

Adaptations of the human placenta to hypoxia: opportunities for interventions in fetal growth restriction

BACKGROUND

The placenta is the functional interface between the mother and the fetus during pregnancy, and a critical determinant of fetal growth and life-long health. In the first trimester, it develops under a low-oxygen environment, which is essential for the conceptus who has little defense against reactive oxygen species produced during oxidative metabolism. However, failure of invasive trophoblasts to sufficiently remodel uterine arteries toward dilated vessels by the end of the first trimester can lead to reduced/intermittent blood flow, persistent hypoxia and oxidative stress in the placenta with consequences for fetal growth. Fetal growth restriction (FGR) is observed in ∼10% of pregnancies and is frequently seen in association with other pregnancy complications, such as preeclampsia (PE). FGR is one of the main challenges for obstetricians and pediatricians, as smaller fetuses have greater perinatal risks of morbidity and mortality and postnatal risks of neurodevelopmental and cardio-metabolic disorders.

OBJECTIVE AND RATIONALE

The aim of this review was to examine the importance of placental responses to changing oxygen environments during abnormal pregnancy in terms of cellular, molecular and functional changes in order to highlight new therapeutic pathways, and to pinpoint approaches aimed at enhancing oxygen supply and/or mitigating oxidative stress in the placenta as a mean of optimizing fetal growth.

SEARCH METHODS

An extensive online search of peer-reviewed articles using PubMed was performed with combinations of search terms including pregnancy, placenta, trophoblast, oxygen, hypoxia, high altitude, FGR and PE (last updated in May 2020).

OUTCOMES

Trophoblast differentiation and placental establishment are governed by oxygen availability/hypoxia in early pregnancy. The placental response to late gestational hypoxia includes changes in syncytialization, mitochondrial functions, endoplasmic reticulum stress, hormone production, nutrient handling and angiogenic factor secretion. The nature of these changes depends on the extent of hypoxia, with some responses appearing adaptive and others appearing detrimental to the placental support of fetal growth. Emerging approaches that aim to increase placental oxygen supply and/or reduce the impacts of excessive oxidative stress are promising for their potential to prevent/treat FGR.

WIDER IMPLICATIONS

There are many risks and challenges of intervening during pregnancy that must be considered. The establishment of human trophoblast stem cell lines and organoids will allow further mechanistic studies of the effects of hypoxia and may lead to advanced screening of drugs for use in pregnancies complicated by placental insufficiency/hypoxia. Since no treatments are currently available, a better understanding of placental adaptations to hypoxia would help to develop therapies or repurpose drugs to optimize placental function and fetal growth, with life-long benefits to human health.

Continuous intrapartum fetal monitoring in gestational diabetes, where is the evidence?

Introduction: Gestational Diabetes Mellitus (GDM) is one of the commonest complications in the pregnancy. It differs in pathogenesis and complications from pre gestational diabetes (PGD), yet the choices of birth and management options for women in labor do not differ between both entities. Materials and method: We have performed literature search to find any evidence behind these recommendations specifically to the subset of pregnant women who have developed diet-controlled GDM, with normal fetal growth. Results: There have been no randomized control trials behind these recommendations. The aforementioned women have comparable outcomes to pregnant women who are not affected by diabetes and can be considered as low risk till any evidence is found. Conclusion: So there is an urgent need to conduct randomized controlled trials on women with well-controlled GDM and normal fetal growth scans so that these women could be provided evidence-based information on their options of birth.

Female Fertility and Environmental Pollution

A realistic picture of our world shows that it is heavily polluted everywhere. Coastal regions and oceans are polluted by farm fertilizer, manure runoff, sewage and industrial discharges, and large isles of waste plastic are floating around, impacting sea life. Terrestrial ecosystems are contaminated by heavy metals and organic chemicals that can be taken up by and accumulate in crop plants, and water tables are heavily contaminated by untreated industrial discharges. As deadly particulates can drift far, poor air quality has become a significant global problem and one that is not exclusive to major industrialized cities. The consequences are a dramatic impairment of our ecosystem and biodiversity and increases in degenerative or man-made diseases. In this respect, it has been demonstrated that environmental pollution impairs fertility in all mammalian species. The worst consequences are observed for females since the number of germ cells present in the ovary is fixed during fetal life, and the cells are not renewable. This means that any pollutant affecting hormonal homeostasis and/or the reproductive apparatus inevitably harms reproductive performance. This decline will have important social and economic consequences that can no longer be overlooked.

Prediction of preeclampsia using first trimester placental protein 13 and uterine artery Doppler

OBJECTIVE

To determine the predictive value for preeclampsia by using serum placental protein 13 (PP13) levels and uterine artery pulsatility index (PI) in the first trimester.

METHODS

This is a prospective observational study that was conducted in pregnant women with gestational age 11-13⁺⁶weeks. Transabdominal uterine artery Doppler and serum PP13 level were performed at the first trimester aneuploidy screening visit. The predictive values of these tests were calculated.

RESULTS

Data from 353 pregnant women were analyzed. Twenty-nine cases developed preeclampsia. The sensitivity, specificity, positive predictive value and negative predictive value of serum PP13 levels in predicting preeclampsia were 51.7, 65.7, 11.9, and 93.8%, respectively. The sensitivity, specificity, positive predictive value and negative predictive value of the uterine artery PI in predicting preeclampsia were 10.3, 95.7, 17.7, and 92.3%, respectively. When a combination of serum PP13 levels and uterine artery PI were used to predict preeclampsia, the sensitivity, specificity, positive predictive value and negative predictive value were 58.6, 62.9, 12.4 and 94.4%, respectively.

CONCLUSION

This study demonstrated that the combination of serum PP13 level and uterine artery Doppler in the first trimester was increased the sensitivity for predicting preeclampsia.