Endovascular trophoblast and spiral artery remodeling

Maternal serum PlGF associates with 3D power doppler ultrasound markers of utero-placental vascular development in the first trimester: the rotterdam periconception cohort

OBJECTIVE (S)

Circulating angiogenic factors are used for prediction of placenta-related complications, but their associations with first-trimester placental development is unknown. This study investigates associations between maternal angiogenic factors and utero-placental vascular volume (uPVV) and utero-placental vascular skeleton (uPVS) as novel imaging markers of volumetric and morphologic (branching) development of the first-trimester utero-placental vasculature.

METHODS

In 185 ongoing pregnancies from the VIRTUAL Placenta study, a subcohort of the ongoing prospective Rotterdam Periconception cohort, three-dimensional power Doppler ultrasounds of the placenta were obtained at 7-9-11 weeks gestational age (GA). The uPVV was measured as a parameter of volumetric development and reported the vascular quantity in cm3. The uPVS was generated as a parameter of morphologic (branching) development and reported the number of end-, bifurcation- crossing- or vessel points and total vascular length. At 11 weeks GA, maternal serum biomarkers suggested to reflect placental (vascular) development were assessed: placental growth factor (PlGF), soluble fms-like tyrosine kinase-1 (sFlt-1) and soluble endoglin (sEng). sFlt-1/PlGF and sEng/PlGF ratios were calculated. Multivariable linear regression with adjustments was used to estimate associations between serum biomarkers and uPVV and uPVS trajectories.

RESULTS

Serum PlGF was positively associated with uPVV and uPVS development (uPVV: β = 0.39, 95% CI = 0.15;0.64; bifurcation points: β = 4.64, 95% CI = 0.04;9.25; crossing points: β = 4.01, 95% CI = 0.65;7.37; total vascular length: β = 13.33, 95% CI = 3.09;23.58, all p-values < 0.05). sEng/PlGF ratio was negatively associated with uPVV and uPVS development. We observed no associations between sFlt-1, sEng or sFlt-1/PlGF ratio and uPVV and uPVS development.

CONCLUSION(S)

Higher first-trimester maternal serum PlGF concentration is associated with increased first-trimester utero-placental vascular development as reflected by uPVV and uPVS. Clinical trial registration number Dutch Trial Register NTR6854.

Umbilical artery half peak systolic velocity deceleration time: a novel Doppler parameter for prediction of neonatal outcomes in pregnant women with preeclampsia

PURPOSE

To assess the effectiveness of half peak systolic velocity deceleration time (hPSV-DT) in predicting neonatal outcomes in pregnant women with preeclampsia and to compare its usefulness with the conventional umbilical artery (UA) pulsatility index (PI) approach.

METHODS

A prospective cohort study was conducted among pregnant women with preeclampsia who were admitted to the Department of Perinatology, Ministry of Health Ankara City Hospital between 01 September 2022 and 01 January 2023 at 28-41 weeks gestational age. 55 patients were divided into two groups: the study group with UA hPSV-DT value < 5th percentile (n = 22) and the control group with UA hPSV-DT value ≥ 5th percentile (n = 33). UA hPSV-DT calculates the time in milliseconds needed to halve the maximal velocity of the UA waveform using Doppler ultrasonography.

RESULTS

Birth weight, gestational age at birth, 1st minute APGAR, 5th minute APGAR, and umbilical cord pH values were significantly lower in the anormal hPSV-DT group (p < 0.05). Additionally, the rates of admission to NICU, respiratory distress syndrome (RDS), delivery time < 34 weeks, and birth weight < 2500 g were significantly more frequent in the anormal hPSV-DT group compared to the normal hPSV-DT group (p < 0.05). UA-PI > 95th percentile was detected in only 2 (8%) of 23 patients whose newborns were admitted to the NICU (p = 0.149), while hPSV-DT < 5th percentile was detected in 16 (69%) of 23 patients (p < 0.001). According to ROC analysis, the area under the curve was 0.82 (95% CI 0.06-0.28) for admission to the NICU. The best balance of sensitivity/specificity in ROC curves was 221.5 (82.6% sensitivity, 69.1% specificity, p < 0.001).

CONCLUSION

UA hPSV-DT was successful in predicting composite adverse perinatal outcomes in pregnant women with preeclampsia. It is a promising novel method that is accurate, quantitative, reproducible, and easily applicable. With further studies, this method may be a primary diagnostic tool in the management of high-risk pregnancies and in determining the optimal timing of delivery.

Single-cell and spatial transcriptomics reveal alterations in trophoblasts at invasion sites and disturbed myometrial immune microenvironment in placenta accreta spectrum disorders

BACKGROUND

Placenta accreta spectrum disorders (PAS) are a severe complication characterized by abnormal trophoblast invasion into the myometrium. The underlying mechanisms of PAS involve a complex interplay of various cell types and molecular pathways. Despite its significance, both the characteristics and intricate mechanisms of this condition remain poorly understood.

METHODS

Spatial transcriptomics (ST) and single-cell RNA sequencing (scRNA-seq), were performed on the tissue samples from four PAS patients, including invasive tissues (ST, n = 3; scRNA-seq, n = 4), non-invasive normal placenta samples (ST, n = 1; scRNA-seq, n = 2). Three healthy term pregnant women provided normal myometrium samples (ST, n = 1; scRNA-seq, n = 2). ST analysis characterized the spatial expression landscape, and scRNA-seq was used to identify specific cellular components in PAS. Immunofluorescence staining was conducted to validate the findings.

RESULTS

ST slices distinctly showed the myometrium in PAS was invaded by three subpopulations of trophoblast cells, extravillous trophoblast cells, cytotrophoblasts, and syncytiotrophoblasts, especially extravillous trophoblast cells. The pathways enriched by genes in trophoblasts, smooth muscle cells (SMC), and immune cells of PAS were mainly associated with immune and inflammation. We identified elevated expression of the angiogenesis-stimulating gene PTK2, alongside the cell proliferation-enhancing gene EGFR, within the trophoblasts of PAS group. Trophoblasts mainly contributed the enhancement of HLA-G and EBI3 signaling, which is crucial in establishing immune escape. Meanwhile, SMC regions in PAS exhibited upregulation of immunomodulatory markers such as CD274, HAVCR2, and IDO1, with CD274 expression experimentally verified to be increased in the invasive SMC areas of the PAS group.

CONCLUSIONS

This study provided information of cellular composition and spatial organization in PAS at single-cell and spatial level. The dysregulated expression of genes in PAS revealed a complex interplay between enhanced immune escape in trophoblasts and immune tolerance in SMCs during invasion in PAS. These findings will enhance our understanding of PAS pathogenesis for developing potential therapeutic strategies.

Circ_0030042 inhibits trophoblast cell growth, invasion and epithelial-mesenchymal transition process in preeclampsia via miR-942-5p/LITAF

BACKGROUND

There is increasing evidence that circular RNAs (circRNAs) are involved in the processes of preeclampsia (PE). Circ_0030042 was found to be abnormally expressed in PE patients. However, the role and molecular mechanism of circ_0030042 in PE progression remains unclear.

METHODS

Quantitative real-time PCR was used for determining the expression of circ_0030042, microRNA (miR)- 942-5p and lipopolysaccharide induced TNF-α factor (LITAF). Trophoblast cell functions were determined using cell counting kit 8 assay, EdU assay, flow cytometry and transwell assay. The protein levels of epithelial-mesenchymal transition (EMT)-related markers and LITAF were examined using western blot analysis. Dual-luciferase reporter assay and RNA pull-down assay were used to verify RNA interaction.

RESULTS

Circ_0030042 had an elevated expression in PE patients, and its overexpression inhibited trophoblast cell growth, invasion, and EMT process. Circ_0030042 served as miR-942-5p sponge, and miR-942-5p inhibitor also reversed the regulation of circ_0030042 on trophoblast cell growth, invasion and EMT process. LITAF was targeted by miR-942-5p, and its knockdown abolished the inhibition effect of miR-942-5p on trophoblast cell growth, invasion, and EMT process. Also, circ_0030042 regulated LITAF expression via sponging miR-942-5p.

CONCLUSION

Circ_0030042 regulated trophoblast cell growth, invasion, and EMT process via the miR-942-5p/LITAF axis, providing a novel insight for PE treatment.

HSPB8 binding to c-Myc alleviates hypoxia/reoxygenation-induced trophoblast cell dysfunction

Preeclampsia (PE) is a pregnancy-specific syndrome with complex pathogenesis. The present study aimed to explore the role of heat shock protein B8 (HSPB8) and c-Myc in trophoblast cell dysfunction using a hypoxia/reoxygenation (H/R)-treated HTR8/SVneo cell model. HSPB8 expression in tissues of patients with PE was analyzed using the Gene Expression Omnibus database. Following detection of HSPB8 expression in H/R-stimulated HTR8/SVneo cells, HSPB8 was overexpressed by transfection of the gene with a HSPB8-specific plasmid. Cell Counting Kit-8, wound healing and Transwell assays were used to evaluate the proliferation, migration and invasion of HTR8/SVneo cells exposed to H/R conditions. Reactive oxygen species (ROS) were determined by 2,7-dichlorodihydrofluorescein diacetate staining. 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazolocarbo-cyanine iodide (JC-1) staining was applied to assess mitochondrial membrane potential. Malondialdehyde (MDA) and superoxide dismutase (SOD) levels were detected using the corresponding commercial kits. In addition, the induction of apoptosis was assessed by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining. Moreover, the Biogrid database predicted that HSPB8 was bound to c-Myc, and a co-immunoprecipitation (Co-IP) assay was used to verify this interaction. Subsequently, c-Myc expression was silenced to conduct rescue experiments in HTR8/SVneo cells exposed to H/R conditions and upregulated HSPB8 expression. Notably, reduced HSPB8 expression was noted in PE tissues and H/R-stimulated HTR8/SVneo cells. HSPB8 enforced expression promoted the proliferation, migration and invasion of HTR8/SVneo cells. Moreover, H/R caused an increase in ROS and MDA levels as well as in TUNEL staining and a decrease in aggregated JC-1 fluorescence and SOD activity levels, which were restored following HSPB8 overexpression. Co-IP confirmed the interaction between HSPB8 and c-Myc. Moreover, knockdown of c-Myc expression compromised the effects of HSPB8 upregulation on trophoblast cell dysfunction following induction of H/R. Collectively, the data indicated that HSPB8 could improve mitochondrial oxidative stress by binding to c-Myc to alleviate trophoblast cell dysfunction. The findings may provide new insights into the pathogenesis of PE and highlight the role of HSPB8/c-Myc in the prevention and treatment of PE in the future.

The Risk of Hypertension and Diabetes Mellitus According to Offspring's Birthweight in Women With Normal Body Mass Index: A Nationwide Population-Based Study

BACKGROUND

Maladaptation to vascular, metabolic, and physiological changes during pregnancy can lead to fetal growth disorders. Moreover, adverse outcomes during pregnancy can further increase the risk of cardiovascular and metabolic diseases in mothers. Delivering a large-for-gestational-age (LGA) baby may indicate a pre-existing metabolic dysfunction, whereas delivering a small-for-gestational-age (SGA) baby may indicate a pre-existing vascular dysfunction. This study aims to assess the risk of hypertension (HTN) and diabetes mellitus (DM) in women with normal body mass index (BMI) scores who did not experience gestational DM or hypertensive disorders during pregnancy based on the offspring's birthweight.

METHODS

This retrospective nationwide study included women with normal BMI scores who delivered a singleton baby after 37 weeks. Women with a history of DM or HTN before pregnancy and those with gestational DM or hypertensive disorders, were excluded from the study. We compared the risk of future maternal outcomes (HTN and DM) according to the offspring's birthweight. Multivariate analyses were performed to estimate the hazard ratio (HR) for the future risk of HTN or DM.

RESULTS

A total of 64,037 women were included in the analysis. Of these, women who delivered very LGA babies (birthweight > 97th percentile) were at a higher risk of developing DM than those who delivered appropriate-for-gestational-age (AGA) babies (adjusted HR = 1.358 [1.068-1.727]), and women who delivered very SGA babies (birthweight < 3rd percentile) were at a higher risk of developing HTN than those who delivered AGA babies (adjusted HR = 1.431 [1.181-1.734]), even after adjusting for age, parity, gestational age at delivery, fetal sex, maternal BMI score, and a history of smoking.

CONCLUSION

These findings provide a novel support for the use of the offspring's birthweight as a predictor of future maternal diseases such as HTN and DM.

microRNA-203 Targets Insulin-Like Growth Factor Receptor 1 to Inhibit Trophoblast Vascular Remodeling to Augment Preeclampsia

OBJECTIVE

Preeclampsia (PE) is a pregnancy-specific condition featured by high blood pressure, edema, and proteinuria. Research about the role of microRNA (miR)-203 in PE remains insufficient. This experiment is designed to investigate the specific role of miR-203 in trophoblasts in PE.

STUDY DESIGN

miR-203 expression in placenta tissues of normal pregnant women and PE patients was examined to analyze the relevance between miR-203 and PE diagnostic efficiency and between miR-203 and blood pressure (systolic pressure and diastolic pressure) and proteinuria of PE patients. miR-203 expression was downregulated in hypoxia-cultured trophoblasts using miR-203 inhibitor to assess matrix metalloproteinase-9 (MMP-9) level. Then, the angiogenesis of trophoblasts with different treatments was determined. Subsequently, the target relation between miR-203 and insulin-like growth factor receptor 1 (IGF-1R) was predicted and verified. Additionally, the effect of IGF-1R in the mechanism of miR-203 modulating trophoblast vascular remodeling was detected.

RESULTS

miR-203 was overexpressed in the placenta of PE patients and it acted as a promising diagnostic indicator for PE. Moreover, miR-203 was positively associated with blood pressure (systolic pressure and diastolic pressure) and proteinuria of PE patients. miR-203 silencing in hypoxia-cultured trophoblasts enhanced trophoblast vascular remodeling. Mechanically, miR-203 bound to IGF-1R to suppress its transcription. IGF-1R downregulation counteracted the promotive effect of miR-203 silencing on trophoblast vascular remodeling.

CONCLUSION

miR-203 was overexpressed in PE, and it targeted IGF-1R to limit trophoblast vascular remodeling.

KEY POINTS

· miR-203 is overexpressed in the placenta of PE patients.. · miR-203 acts as a potential diagnostic marker for PE.. · miR-203 targets IGF-1R to reduce trophoblast vascular remodeling in PE..

Visual identification of three kinds of human decidual tissues from elective termination of pregnancy

INTRODUCTION

The decidua can be classified into the decidua basalis, decidua capsularis and decidua parietalis. This study aimed to visually identify these three kinds of decidual tissues from fresh samples obtained in early pregnancy based on their macroscopic appearances, which can be discerned visually.

METHODS

Decidual samples were collected from 15 pregnant women between 6 and 8 weeks of gestation after elective termination of pregnancy. We identified the three different kinds of fresh decidual tissues in early pregnancy according to their different macroscopic appearances by only the naked eye. H&E staining, in situ immunofluorescence and flow cytometry were performed to confirm the accuracy of this method.

RESULTS

We developed a method to discern the three different kinds of decidual tissues according to their individual macroscopic features. We found that the decidua parietalis was a thick tissue with less blood, with one side being intact epidermis and the other side being rough tissue. The decidua basalis had rough surfaces, a dense texture and high blood content. The decidua capsularis was a thin membrane tissue with or without blood clots. CK+/HLA-G+ extravillous trophoblast cells (EVTs) and heme oxygenase-1+ (HMOX1+) decidual macrophages were present in large quantities in the decidua basalis and decidua capsularis but were nearly undetectable in the decidua parietalis. We also found a wide distribution of endovascular extravillous trophoblast cells (enEVTs), which participate in spiral artery remodelling in the decidua basalis.

DISCUSSION

We successfully identified three kinds of human decidual tissues from early pregnancy with the naked eye for the first time. This breakthrough method will greatly assist studies related to decidua during early pregnancy.

Down-regulated Wnt7a and GPR124 in early-onset preeclampsia placentas reduce invasion and migration of trophoblast cells

OBJECTIVES

Preeclampsia (PE) is a disease specific to pregnancy that causes 9-10 % of maternal deaths. Early-onset PE (<34 weeks' gestation) is the most dangerous category of PE. Wnt7a and GPR124 (G protein-coupled receptor 124) are widely expressed in the human reproductive process. Especially during embryogenesis and tumorigenesis, Wnt7a plays a crucial role. However, few studies have examined the association between Wnt7a-GPR124 and early-onset PE. The aim of this study was to examine the significance of Wnt7a and GPR124 in early-onset PE as well as Wnt7a's role in trophoblast cells.

METHODS

Immunohistochemistry (IHC), real-time PCR, and western blotting (WB) were used to investigate Wnt7a and GPR124 expression in normal and early-onset PE placentas. Additionally, FACS, Transwell, and CCK-8 assays were used to diagnose Wnt7a involvement in migration, invasion, and proliferation.

RESULTS

In the early-onset PE group, Wnt7a and GPR124 expression was significantly lower than in the normal group, especially in the area of syncytiotrophoblasts (STBs) and extravillous trophoblasts (EVTs). A negative correlation was found between Wnt7a RNA and GPR124 expression (r=-0.42, p<0.01). However, the Wnt7a RNA expression level was positive correlated with PE severity. In further cellular functional experiments, knockdown of Wnt7a inhibits HTR8/SVeno cells invasion and migration but has little effect on proliferation and apoptosis.

CONCLUSIONS

Through the Wnt pathway, Wnt7a regulates trophoblast cell invasion and migration, and may contribute to early-onset preeclampsia pathogenesis. A molecular level study of Wnt7a will be needed to find downstream proteins and mechanisms of interaction.

Thick endometrium is associated with hypertensive disorders of pregnancy in programmed frozen-thawed embryo transfers: a retrospective analysis of 2,275 singleton deliveries

OBJECTIVE

To investigate whether endometrial thickness (EMT) acts as a contributing factor to adverse perinatal outcomes in programmed frozen-thawed embryo transfer (FET) cycles.

DESIGN

Retrospective cohort study.

SETTING

University-based reproductive medical center.

SUBJECT

The study included singleton live births resulting from programmed FET cycles that took place between January 2017 and April 2022 (N = 2,275 cycles).

EXPOSURE

The EMT measurement conducted on the day of progesterone initiation was utilized. Programmed FET cycles with EMT <7 mm were excluded from consideration. All included subjects were divided into 4 groups on the basis of the 10th, 50th, and 90th percentiles of EMT: group Ⅰ (EMT ≤8 mm, n = 193), group Ⅱ (EMT = 8.1-10 mm, n = 1,261), group Ⅲ (EMT = 10.1-12 mm, n = 615), and group Ⅳ (EMT >12 mm, n = 206). After adjusting for patient demographics and FET parameters, logistic regression analysis and restricted cubic spline were used to investigate the relationship between EMT and perinatal outcomes. The group Ⅱ (EMT = 8.1-10 mm) served as a reference.

MAIN OUTCOME MEASURE(S)

The primary outcome measure was the hypertensive disorders of pregnancy (HDP). Secondary outcomes included gestational diabetes mellitus, cesarean delivery, placenta previa, premature rupture of membrane, birthweight, preterm birth, low birthweight, macrosomia, small for gestational age, large for gestational age and neonatal morbidity.

RESULTS(S)

The incidence of HDP was substantially elevated in group Ⅳ when compared with the other groups (5.7% vs. 4.1% vs. 5.7% vs. 9.7% for groups Ⅰ-Ⅳ, respectively). In addition, group I displayed a higher incidence of cesarean deliveries, whereas both group I and group IV exhibited an elevated prevalence of placenta previa. After adjusting for confounding factors, patients in group IV exhibited a significantly increased risk of HDP (adjusted odds ratio [OR] = 2.03, 95% confidence interval [CI] 1.13-3.67) as compared with patients in the reference group. The restricted cubic spline model revealed a nonlinear association between EMT and the odds of HDP on continuous scales. In comparison to women with an EMT of 9.5 mm, there was no significant change in the risk of HDP in women with EMT between 7 and 11 mm, as indicated by adjusted ORs of 1.37 (95% CI 0.41-4.52), 1.34 (95% CI 0.73-2.47), 1.13 (95% CI 0.79-1.62), 1.04 (95% CI 0.87-1.25), and 1.46 (95% CI 0.81-2.65), respectively. However, the risk of HDP was significantly higher in women with EMT ranging from 12 to 15 mm, with adjusted ORs of 1.86 (95% CI 1.03-3.35), 2.33 (95% CI 1.32-4.12), 2.92 (95% CI 1.52-5.60), and 3.62 (95% CI 1.63-8.04), respectively.

CONCLUSION(S)

This study demonstrated a noteworthy association between EMT and adverse perinatal outcomes during the programmed FET cycles. Specifically, a thick endometrium (EMT >12 mm) was independently associated with an increased risk of developing HDP, whereas the optimal EMT for reducing the risk of HDP was at around 9-10 mm.

Placental single cell transcriptomics: Opportunities for endocrine disrupting chemical toxicology

The placenta performs essential biologic functions for fetal development throughout pregnancy. Placental dysfunction is at the root of multiple adverse birth outcomes such as intrauterine growth restriction, preeclampsia, and preterm birth. Exposure to endocrine disrupting chemicals during pregnancy can cause placental dysfunction, and many prior human studies have examined molecular changes in bulk placental tissues. Placenta-specific cell types, including cytotrophoblasts, syncytiotrophoblasts, extravillous trophoblasts, and placental resident macrophage Hofbauer cells play unique roles in placental development, structure, and function. Toxicant-induced changes in relative abundance and/or impairment of these cell types likely contribute to placental pathogenesis. Although gene expression insights gained from bulk placental tissue RNA-sequencing data are useful, their interpretation is limited because bulk analysis can mask the effects of a chemical on individual populations of placental cells. Cutting-edge single cell RNA-sequencing technologies are enabling the investigation of placental cell-type specific responses to endocrine disrupting chemicals. Moreover, in situ bioinformatic cell deconvolution enables the estimation of cell type proportions in bulk placental tissue gene expression data. These emerging technologies have tremendous potential to provide novel mechanistic insights in a complex heterogeneous tissue with implications for toxicant contributions to adverse pregnancy outcomes.

Maternal birth weight as an indicator of early-onset and late-onset hypertensive disorders of pregnancy: The Japan Environment and Children's study

OBJECTIVES

This study aimed to investigate the association between maternal birth weight (MBW) and hypertensive disorders of pregnancy (HDP) according to the gestational age when HDP develops.

STUDY DESIGN

A total of 77,345 subjects were included in this prospective birth cohort study. The association between MBW and HDP was investigated by a multinomial logistic regression model.

MAIN OUTCOME MEASURES

Early-onset HDP (EO-HDP), preterm late-onset HDP (preterm LO-HDP), and term late-onset HDP (term LO-HDP).

RESULTS

Lower MBW was associated with higher odds of preterm and term LO-HDP (p-values for trend < 0.0001 and = 0.0005, respectively). A linear association between MBW and EO-HDP was observed (p-values for trend = 0.0496). The shape of the association between MBW and preterm LO-HDP was a combination of the associations between MBW with EO-HDP or LO-HDP. The effect size of the association between MBW < 2,500 g and EO-HDP was lower than that of MBW < 2,500 g with preterm or term LO-HDP. The adjusted odds ratios for EO-HDP, preterm LO-HDP, and term LO-HDP in subjects with MBW < 2,500 g were 1.052 (95 % confidence interval [CI]: 0.665-1.664), 1.745 (95 % CI: 1.220-2.496), and 1.496 (95 % CI: 1.154-1.939), respectively.

CONCLUSIONS

MBW was associated with HDP, regardless of gestational age when HDP developed. Furthermore, the association of MBW < 2,500 g with preterm or term LO-HDP was stronger than that with EO-HDP.

Unveiling the dual role of autophagy in vascular remodelling and its related diseases

Vascular remodelling is an adaptive response to physiological and pathological stimuli that leads to structural and functional changes in the vascular intima, media, and adventitia. Pathological vascular remodelling is a hallmark feature of numerous vascular diseases, including atherosclerosis, hypertension, abdominal aortic aneurysm, pulmonary hypertension and preeclampsia. Autophagy is critical in maintaining cellular homeostasis, and its dysregulation has been implicated in the pathogenesis of various diseases, including vascular diseases. However, despite emerging evidence, the role of autophagy and its dual effects on vascular remodelling has garnered limited attention. Autophagy can exert protective and detrimental effects on the vascular intima, media and adventitia, thereby substantially influencing the course of vascular remodelling and its related vascular diseases. Currently, there has not been a review that thoroughly describes the regulation of autophagy in vascular remodelling and its impact on related diseases. Therefore, this review aimed to bridge this gap by focusing on the regulatory roles of autophagy in diseases related to vascular remodelling. This review also summarizes recent advancements in therapeutic agents targeting autophagy to regulate vascular remodelling. Additionally, this review offers an overview of recent breakthroughs in therapeutic agents targeting autophagy to regulate vascular remodelling. A deeper understanding of how autophagy orchestrates vascular remodelling can drive the development of targeted therapies for vascular diseases.

Gestational ozone inhalation elicits maternal cardiac dysfunction and transcriptional changes to placental pericytes and endothelial cells

Ozone (O3) is a criteria air pollutant with the most frequent incidence of exceeding air quality standards. Inhalation of O3 is known to cause lung inflammation and consequent systemic health effects, including endothelial dysfunction. Epidemiologic data have shown that gestational exposure to air pollutants correlates with complications of pregnancy, including low birth weight, intrauterine growth deficiency, preeclampsia, and premature birth. Mechanisms underlying how air pollution may facilitate or exacerbate gestational complications remain poorly defined. The current study sought to uncover how gestational O3 exposure impacted maternal cardiovascular function, as well as the development of the placenta. Pregnant mice were exposed to 1PPM O3 or a sham filtered air (FA) exposure for 4 h on gestational day (GD) 10.5, and evaluated for cardiac function via echocardiography on GD18.5. Echocardiography revealed a significant reduction in maternal stroke volume and ejection fraction in maternally exposed dams. To examine the impact of maternal O3 exposure on the maternal-fetal interface, placentae were analyzed by single-cell RNA sequencing analysis. Mid-gestational O3 exposure led to significant differential expression of 4021 transcripts compared with controls, and pericytes displayed the greatest transcriptional modulation. Pathway analysis identified extracellular matrix organization to be significantly altered after the exposure, with the greatest modifications in trophoblasts, pericytes, and endothelial cells. This study provides insights into potential molecular processes during pregnancy that may be altered due to the inhalation of environmental toxicants.

Platelet and mitochondrial RNA is decreased in plasma-derived extracellular vesicles in women with preeclampsia-an exploratory study

BACKGROUND

Circulating extracellular vesicles (EVs) are increased in preeclampsia (PE) and are associated with severity and progression. We examined in this exploratory cohort study if the mRNAs and long noncoding RNAs (lncRNAs) in plasma-derived EVs were dysregulated in PE compared to normal pregnancy and display different temporal patterns during gestation.

METHODS

We isolated EVs from plasma at weeks 22-24 and 36-38 in women with and without PE (n=7 in each group) and performed RNA-seq, focusing on mRNAs and lncRNAs. We validated highly expressed mitochondrial and platelet-derived RNAs discovered from central pathways in 60 women with/without PE. We examined further one of the regulated RNAs, noncoding mitochondrially encoded tRNA alanine (MT-TA), in leukocytes and plasma to investigate its biomarker potential and association with clinical markers of PE.

RESULTS

We found abundant levels of platelet-derived and mitochondrial RNAs in EVs. Expression of these RNAs were decreased and lncRNAs increased in EVs from PE compared to without PE. These findings were further validated by qPCR for mitochondrial RNAs MT-TA, MT-ND2, MT-CYB and platelet-derived RNAs PPBP, PF4, CLU in EVs. Decreased expression of mitochondrial tRNA MT-TA in leukocytes at 22-24 weeks was strongly associated with the subsequent development of PE.

CONCLUSIONS

Platelet-derived and mitochondrial RNA were highly expressed in plasma EVs and were decreased in EVs isolated from women with PE compared to without PE. LncRNAs were mostly increased in PE. The MT-TA in leukocytes may be a useful biomarker for prediction and/or early detection of PE.

Exploring maternal-fetal interface with in vitro placental and trophoblastic models

The placenta, being a temporary organ, plays a crucial role in facilitating the exchange of nutrients and gases between the mother and the fetus during pregnancy. Any abnormalities in the development of this vital organ not only lead to various pregnancy-related disorders that can result in fetal injury or death, but also have long-term effects on maternal health. In vitro models have been employed to study the physiological features and molecular regulatory mechanisms of placental development, aiming to gain a detailed understanding of the pathogenesis of pregnancy-related diseases. Among these models, trophoblast stem cell culture and organoids show great promise. In this review, we provide a comprehensive overview of the current mature trophoblast stem cell models and emerging organoid models, while also discussing other models in a systematic manner. We believe that this knowledge will be valuable in guiding further exploration of the complex maternal-fetal interface.

IL-21R-STAT3 signalling initiates a differentiation program in uterine tissue-resident NK cells to support pregnancy

Tissue-resident Natural Killer (trNK) cells are crucial components of local immunity that activate rapidly upon infection. However, under steady state conditions, their responses are tightly controlled to prevent unwanted tissue damage. The mechanisms governing their differentiation and activation are not fully understood. Here, we characterise uterine trNK cells longitudinally during pregnancy by single cell RNA sequencing and find that the combined expression pattern of 4-1BB and CD55 defines their three distinct stages of differentiation in mice. Mechanistically, an IL-21R-STAT3 axis is essential for initiating the trNK cell differentiation. The fully differentiated trNK cells demonstrate enhanced functionality, which is necessary for remodelling spiral arteries in the decidua. We identify an apoptotic program that is specific to the terminal differentiation stage, which may preclude tissue damage by these highly activated trNK cells. In summary, uterine trNK cells become intensely active and effective during pregnancy, but tightly controlled via a differentiation program that also limits potential harm, suggesting an intricate mechanism for harnessing trNK cells in maintaining pregnancy.

The Value of Ultrasonic Elastography in Detecting Placental Stiffness for the Diagnosis of Preeclampsia: A Meta-Analysis

This meta-analysis evaluated the diagnostic value of ultrasonic elastography in detecting placental stiffness in the diagnosis of preeclampsia (PE). A systematic search was conducted in the EMBASE, Web of Science, Cochrane Library, Scopus database, and PubMed databases to identify studies published before June 2023 using ultrasonic elastography to diagnose PE. The sensitivity, specificity, and diagnostic odds ratio of ultrasonic elastography for diagnosing PE were calculated, and a summary receiver operating characteristic curve model was constructed. The degree of heterogeneity was estimated using the I2 statistic, and a meta-regression analysis was performed to explore its sources. A protocol was determined previously (PROSPERO: CRD42023443646). We included 1188 participants from 11 studies, including 190 patients with PE and 998 patients without PE as controls. Overall sensitivity and specificity of ultrasonic elastography in detecting placental stiffness for the diagnosis of PE were 89% (95% CI: 85-93) and 74% (95% CI: 51-89), respectively. The I2 values for sensitivity and specificity were 59% (95% CI: 29-89) and 96% (95% CI: 95-98), respectively. The area under the receiver operating characteristic curve was 0.90 (95% CI: 0.87-0.92). The meta-regression analysis showed no significant heterogeneity. Ultrasonic elastography exhibits good diagnostic accuracy for detecting placental stiffness and can serve as a non-invasive tool for differentially diagnosing PE.

Decidualized human decidual stromal cells inhibit chemotaxis of activated T cells: a potential mechanism of maternal-fetal immune tolerance

Background

Numerous lines of evidence confirm that decidual stromal cells (DSCs) play a key role in maternal-fetal immune tolerance. Under the influence of progesterone and other hormones, the DSCs go through a process of differentiation (decidualization) during normal pregnancy. In mice, DSCs inhibit the expression of chemokines that attract abortigenic Th1 and Tc cells to the decidua. We have studied this phenomenon in humans.

Methods

We established human DSC lines and decidualized these cells in vitro with progesterone and cAMP. We determined the expression of the chemokines CXCL9, CXCL10 and CXCL11, whose receptor CXCR3 is expressed by Th1 and Tc cells, in undifferentiated DSCs and decidualized DSCs by qRT-PCR. Activated CD3+CXCR3+ cells, including CD4+ Th1 cells and CD8+ Tc cells, were induced in vitro. The migration capacity of these activated lymphocytes was investigated in Transwell chambers with conditioned media from undifferentiated and decidualized DSCs.

Results

We demonstrated that CXCL9 was not expressed by DSCs, whereas the expression of CXCL10 and CXCL11 was inhibited in decidualized cells. Conditioned media from decidualized cells significantly inhibited the migration of Th1 and Tc cells. We found that decidualized cells secrete factors of MW less than 6000-8000 Da, which actively inhibit the chemotaxis of these lymphocytes.

Discussion

These results confirm in humans that decidualization of DSCs inhibits the expression by these cells of chemokines that attract Th1 and Tc cells and induces the secretion by DSCs of factors that inhibit the chemotaxis of these lymphocytes, thus preventing the arrival of abortigenic T cells in the decidua.

Identifying sensitive windows of prenatal household air pollution on birth weight and infant pneumonia risk to inform future interventions

BACKGROUND

Prenatal household air pollution impairs birth weight and increases pneumonia risk however time-varying associations have not been elucidated and may have implications for the timing of public health interventions.

METHODS

The Ghana Randomized Air Pollution and Health Study (GRAPHS) enrolled 1,414 pregnant women from Kintampo, Ghana and measured personal carbon monoxide (CO) exposure four times over pregnancy. Birth weight was measured within 72-hours of birth. Fieldworkers performed weekly pneumonia surveillance and referred sick children to study physicians. The primary pneumonia outcome was one or more physician-diagnosed severe pneumonia episode in the first year of life. We employed reverse distributed lag models to examine time-varying associations between prenatal CO exposure and birth weight and infant pneumonia risk.

RESULTS

Analyses included n = 1,196 mother-infant pairs. In models adjusting for child sex; maternal age, body mass index (BMI), ethnicity and parity at enrollment; household wealth index; number of antenatal visits; and evidence of placental malaria, prenatal CO exposures from 15 to 20 weeks gestation were inversely associated with birth weight. Sex-stratified models identified a similar sensitive window in males and a window at 10-weeks gestation in females. In models adjusting for child sex, maternal age, BMI and ethnicity, household wealth index, gestational age at delivery and average postnatal child CO exposure, CO exposure during 34-39 weeks gestation were positively associated with severe pneumonia risk, especially in females.

CONCLUSIONS

Household air pollution exposures in mid- and late- gestation are associated with lower birth weight and higher pneumonia risk, respectively. These findings support the urgent need for deployment of clean fuel stove interventions beginning in early pregnancy.

MALAT1 modulates trophoblast phenotype via miR-101-3p/VEGFA axis

Preeclampsia is a potentially life-threatening condition that can arise due to poor placentation and consequent abnormal uterine spiral artery remodeling. Abnormal placentation, in turn, is associated with aberrant trophoblast cell proliferation and apoptosis. Here, we investigated the lncRNA MALAT1 in trophoblast proliferation during early-onset preeclampsia (ePE). MALAT1 levels were examined in placental tissue samples from ePE patients and control patients. The effects and underlying mechanism of MALAT1 on proliferation, migration, invasion and apoptosis were investigated in the first-trimester extravillous trophoblast HTR-8/SVneo cells and the human choriocarcinoma JAR cells. MALAT1 levels were decreased in the placental tissue samples of ePE patients compared with those of control patients, and the levels of MALAT1 were positively correlated with the neonate birth-weight. Knockdown of MALAT1 attenuated the cell viability, proliferation, migration, invasion and the cell cycle progression of trophoblasts, but promoted the apoptosis of trophoblasts. The MALAT1 knockdown promoted miR-101-3p upregulation and VEGFA downregulation. Inhibitor of miR-101-3p increased vascular endothelial growth factor A (VEGFA) expression, and miR-101-3p mimic inhibited VEGFA expression. Luciferase assays showed that miR-101-3p could bind to both MALAT1 and VEGFA. The MALAT1 knockdown-induced induction in the cell vitality and proliferation were attenuated by miR-101-3p inhibitor. We conclude that endogenous MALAT1 promotes proliferation, migration and invasion of trophoblasts by inhibiting the miR-101-3p expression and the subsequent VEGFA downregulation. The reduced MALAT1 level in placental tissue may be involved in the pathogenesis of the ePE.

RBM25 induces trophoblast epithelial-mesenchymal transition and preeclampsia disorder by enhancing the positive feedback loop between Grhl2 and RBM25

Defects in migration and invasion caused by dysregulation of trophoblast epithelial-mesenchymal transformation (EMT) are one of the key factors in the pathogenesis of preeclampsia (PE). RNA-binding motif protein 25 (RBM25) is an RNA-binding protein involved in a variety of cellular processes, including cell proliferation, apoptosis, cell migration and invasion, and EMT. However, the expression and function of RBM25 in placental of PE remain unclear. In this study, we reveal that the expression of RBM25 is significantly elevated in PE placental tissue. RBM25 depletion and over-expression in trophoblast cells increase and decrease, respectively, cell migration and invasion by regulating EMT marker E-cadherin and Vimentin expression. Mechanistically, Grhl2 is involved in RBM25-regulated trophoblast cell migration, invasion, and EMT through RBM25-facilitated mRNA stabilization. Furthermore, the upregulation of Grhl2 enhances the expression of RBM25 through transcription and forms a positive feedback regulation in the progression of PE. These findings suggest that upregulation of RBM25 induces dysregulation of trophoblast EMT by enhancing positive feedback regulation of Grhl2 and RBM25, leading to defects in cell migration and invasion. Targeting this newly identified regulatory axis may provide benefits in the prevention and treatment of PE.

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.

Identifying a dynamic transcriptomic landscape of the cynomolgus macaque placenta during pregnancy at single-cell resolution

Supporting healthy pregnancy outcomes requires a comprehensive understanding of the cellular hierarchy and underlying molecular mechanisms in the primate placenta during gestation. Here, we present a single-cell transcriptome-wide view of the cynomolgus macaque placenta throughout gestation. Bioinformatics analyses and multiple validation experiments suggested that placental trophoblast cells exhibited stage-specific differences across gestation. Interactions between trophoblast cells and decidual cells also showed gestational stage-dependent differences. The trajectories of the villous core cells indicated that placental mesenchymal cells were derived from extraembryonic mesoderm (ExE.Meso) 1, whereas placental Hofbauer cells, erythrocytes, and endothelial cells were derived from ExE.Meso2. Comparative analyses of human and macaque placentas uncovered conserved features of placentation across species, and the discrepancies of extravillous trophoblast cells (EVTs) between human and macaque correlated to their differences in invasion patterns and maternal-fetal interactions. Our study provides a groundwork for elucidating the cellular basis of primate placentation.

Understanding the Role of Chemerin in the Pathophysiology of Pre-Eclampsia

Chemerin is a multifaceted adipokine that is involved in multiple biological processes, including inflammation, angiogenesis, adipogenesis, and energy metabolism, as well as oxidative stress. There is a vast body of evidence for a crucial role of chemerin in the development of different cardiovascular diseases. Blood chemerin levels, as well as its placental expression, are elevated in patients with pre-eclampsia (PE) and correlate positively with the severity of the disease. This narrative review summarizes the current knowledge about the potential role of chemerin during PE development, with a particular focus on its involvement in oxidative stress and endothelial dysfunction.

Comparison of different modified operations in the reduced uteroplacental perfusion pressure rat model of preeclampsia

INTRODUCTION

Animal models are indispensable tools in studying the mechanisms underlying the diseases. Rat models with reduced uterine perfusion pressure (RUPP) were able to mimic the pathophysiological traits of placental ischemia and hypoxia in preeclampsia (PE). However, ischemic injury can lead to a cascade of damage to lower limb ischemia in RUPP. Therefore, the aim of our study was to compare three modified surgical procedures of reducing uteroplacental perfusion pressure, and to provide a reference for the recognition of different PE phenotypes in the future.

MATERIAL AND METHODS

To establish a specific uteroplacental malperfusion model of PE in rats, we bilaterally ligated uterine vessels (UU), ovarian vessels distal to ovarian branches (OO), or both (sRUPP) at 13.5 days post coitum. 21 Sprague-Dawley rats in total were used and were divided into four groups: Sham (n = 4), UU (n = 6), OO (n = 5) and sRUPP (n = 8).

RESULTS

The results showed that the OO and sRUPP groups could successfully mimic the phenotypes of PE while UU group not. Then, autophagy, apoptosis, and synthesis of unsaturated fatty acids were increased in both the OO and sRUPP groups compared with the Sham group, while inflammation were not statistically different.

CONCLUSIONS

The OO and sRUPP groups could successfully establish the rat model of PE while the UU group not. Notably, between the OO and sRUPP groups, the OO group has a higher fetal survival rate and might be more suitable for studying fetal-related questions, while the sRUPP group has a heavier phenotypic profile and is more suitable for studying maternal phenotypes related to PE.

Natural Killer Cell Derived Microvesicles Affect the Function of Trophoblast Cells

The interaction of natural killer (NK) and trophoblast cells underlies the formation of immune tolerance in the mother-fetus system and the maintenance of the physiological course of pregnancy. In addition, NK cells affect the function of trophoblast cells, interacting with them via the receptor apparatus and through the production of cytokines. Microvesicles (MVs) derived from NK cells are able to change the function of target cells. However, in the overall pattern of interactions between NK cells and trophoblasts, the possibility that both can transmit signals to each other via MVs has not been taken into account. Therefore, the aim of this study was to assess the effect of NK cell-derived MVs on the phenotype, proliferation, and migration of trophoblast cells and their expression of intracellular messengers. We carried out assays for the detection of content transferred from MV to trophoblasts. We found that NK cell-derived MVs did not affect the expression of CD54, CD105, CD126, CD130, CD181, CD119, and CD120a receptors in trophoblast cells or lead to the appearance of CD45 and CD56 receptors in the trophoblast membrane. Further, the MVs reduced the proliferation but increased the migration of trophoblasts with no changes to their viability. Incubation of trophoblast cells in the presence of MVs resulted in the activation of STAT3 via pSTAT3(Ser727) but not via pSTAT3(Tyr705). The treatment of trophoblasts with MVs did not result in the phosphorylation of STAT1 and ERK1/2. The obtained data indicate that NK cell-derived MVs influence the function of trophoblast cells, which is accompanied by the activation of STAT3 signaling.

Hyperin promotes proliferation, migration, and invasion of HTR-8/SVneo trophoblast cells via activation of JAK1/STAT3 pathway in recurrent spontaneous abortions

The proliferation of extravillous trophoblasts (EVT) and their further migration, invasion, and differentiation into the decidual and myometrial vasculature are vital for spiral artery remodeling. These physiological functions of EVT are also essential steps in the implantation of the human embryo and the formation of the placenta and are closely related to pregnancy maintenance and the occurrence of abortion. Hyperin is a flavonoid with anti-inflammatory, pro-proliferative, and anti-apoptotic properties. Consequently, we investigated the previously unexplored effects of hyperin on the proliferation, migration, and invasion of HTR-8/SVneo cells. Human extravillous trophoblast-derived HTR-8/SVneo cells were incubated with different concentrations of hyperin (0, 5, 10, 25, 50, and 100 μM) to observe the changes in cell proliferation, migration, invasive capacity, and pathway activation. Proliferation, migration, and invasion were promoted by activating the JAK1/STAT3 pathway in HTR-8/SVneo cells treated with hyperin. In addition, brepocitinib (PF-06700841) significantly inhibited the proliferation, migration, and invasion effects of hyperin on HTR-8/SVneo cells. In vivo experiments confirmed that hyperin reduces the embryo loss rate in recurrent spontaneous abortion (RSA) model mice. Furthermore, our study revealed that hyperin promoted the proliferation, migration, and invasion of HTR-8/SVneo cells via activation of the JAK1/STAT3 pathway, further improving pregnancy outcomes in RSA.

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.

Hyperglycemia disturbs trophoblast functions and subsequently leads to failure of uterine spiral artery remodeling

Uterine spiral artery remodeling is necessary for fetal growth and development as well as pregnancy outcomes. During remodeling, trophoblasts invade the arteries, replace the endothelium and disrupt the vascular smooth muscle, and are strictly regulated by the local microenvironment. Elevated glucose levels at the fetal-maternal interface are associated with disorganized placental villi and poor placental blood flow. Hyperglycemia disturbs trophoblast proliferation and invasion via inhibiting the epithelial-mesenchymal transition, altering the protein expression of related proteases (MMP9, MMP2, and uPA) and angiogenic factors (VEGF, PIGF). Besides, hyperglycemia influences the cellular crosstalk between immune cells, trophoblast, and vascular cells, leading to the failure of spiral artery remodeling. This review provides insight into molecular mechanisms and signaling pathways of hyperglycemia that influence trophoblast functions and uterine spiral artery remodeling.

Single-Cell Immunobiology of the Maternal-Fetal Interface

Pregnancy success requires constant dialogue between the mother and developing conceptus. Such crosstalk is facilitated through complex interactions between maternal and fetal cells at distinct tissue sites, collectively termed the "maternal-fetal interface." The emergence of single-cell technologies has enabled a deeper understanding of the unique processes taking place at the maternal-fetal interface as well as the discovery of novel pathways and immune and nonimmune cell types. Single-cell approaches have also been applied to decipher the cellular dynamics throughout pregnancy, in parturition, and in obstetrical syndromes such as recurrent spontaneous abortion, preeclampsia, and preterm labor. Furthermore, single-cell technologies have been used during the recent COVID-19 pandemic to evaluate placental viral cell entry and the impact of SARS-CoV-2 infection on maternal and fetal immunity. In this brief review, we summarize the current knowledge of cellular immunobiology in pregnancy and its complications that has been generated through single-cell investigations of the maternal-fetal interface.

Circular RNA hsa-circ-0005238 enhances trophoblast migration, invasion and suppresses apoptosis via the miR-370-3p/CDC25B axis

Background

Fetal growth restriction (FGR) is attributed to various maternal, fetal, and placental factors. Trophoblasts participate in the establishment and maintenance of pregnancy from implantation and placentation to providing nutrition to fetus. Studies have reported that impaired trophoblast invasion and proliferation are among factors driving development of FGR. Circular RNAs (circRNAs) can regulate trophoblast function. We assessed the significance of circRNAs underlying FGR development.

Materials and methods

Next generation sequencing (NGS) was carried out to quantify levels of circRNAs in placenta tissues with and without FGR. In vitro experiments including transfection, (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2Htetrazolium) (MTS) assays, flow cytometry analyses, Transwell assays, wound healing assays, western blotting, qRT-PCR, dual-luciferase assays, immunofluorescence staining, and RIP assay were performed.

Results

There were 18 differentially expressed circRNAs between FGR placentas and uncomplicated pregnancies, while levels of hsa-circ-0005238 were markedly low in FGR placentas. Our in vitro experiments further revealed that hsa-circ-0005238 suppressed apoptosis and enhanced proliferation, migration, invasion of trophoblast cell lines. The hsa-miR-370-3p was identified as a direct target of hsa-circ-0005238. Mechanistically, hsa-miR-370-3p prevents invasion as well as migration of trophoblast cells by downregulating CDC25B.

Conclusion

The hsa-circ-0005238 modulates FGR pathogenesis by inhibiting trophoblast cell invasion and migration through sponging hsa-miR-370-3p. Hence, targeting this circRNA may be an attractive strategy for FGR treatment.

Assessment of first-trimester utero-placental vascular morphology by 3D power Doppler ultrasound image analysis using a skeletonization algorithm: the Rotterdam Periconception Cohort

STUDY QUESTION

Can three-dimensional (3D) Power Doppler (PD) ultrasound and a skeletonization algorithm be used to assess first-trimester development of the utero-placental vascular morphology?

SUMMARY ANSWER

The application of 3D PD ultrasonography and a skeletonization algorithm facilitates morphologic assessment of utero-placental vascular development in the first trimester and reveals less advanced vascular morphologic development in pregnancies with placenta-related complications than in pregnancies without placenta-related complications.

WHAT IS KNOWN ALREADY

Suboptimal development of the utero-placental vasculature is one of the main contributors to the periconceptional origin of placenta-related complications. The nature and attribution of aberrant vascular structure and branching patterns remain unclear, as validated markers monitoring first-trimester utero-placental vascular morphologic development are lacking.

STUDY DESIGN, SIZE, DURATION

In this prospective observational cohort, 214 ongoing pregnancies were included before 10 weeks gestational age (GA) at a tertiary hospital between January 2017 and July 2018, as a subcohort of the ongoing Rotterdam Periconception Cohort study.

PARTICIPANTS/MATERIALS, SETTING, METHODS

By combining 3D PD ultrasonography and virtual reality, utero-placental vascular volume (uPVV) measurements were obtained at 7, 9 and 11 weeks GA. A skeletonization algorithm was applied to the uPVV measurements to generate the utero-placental vascular skeleton (uPVS), a network-like structure containing morphologic characteristics of the vasculature. Quantification of vascular morphology was performed by assigning a morphologic characteristic to each voxel in the uPVS (end-, vessel-, bifurcation- or crossing-point) and calculating total vascular network length. A Mann–Whitney U test was performed to investigate differences in morphologic development of the first-trimester utero-placental vasculature between pregnancies with and without placenta-related complications. Linear mixed models were used to estimate trajectories of the morphologic characteristics in the first trimester.

MAIN RESULTS AND THE ROLE OF CHANCE

All morphologic characteristics of the utero-placental vasculature increased significantly in the first trimester (P < 0.005). In pregnancies with placenta-related complications (n = 54), utero-placental vascular branching was significantly less advanced at 9 weeks GA (vessel points P = 0.040, bifurcation points P = 0.050, crossing points P = 0.020, total network length P = 0.023). Morphologic growth trajectories remained similar after adjustment for parity, conception mode, foetal sex and occurrence of placenta-related complications.

LIMITATIONS, REASONS FOR CAUTION

The tertiary setting of this prospective observational study provides high internal, but possibly limited external, validity. Extrapolation of the study’s findings should therefore be addressed with caution.

WIDER IMPLICATIONS OF THE FINDINGS

The uPVS enables assessment of morphologic development of the first-trimester utero-placental vasculature. Further investigation of this innovative methodology needs to determine its added value for the assessment of (patho-) physiological utero-placental vascular development.

STUDY FUNDING/COMPETING INTEREST(S)

This research was funded by the Department of Obstetrics and Gynecology of the Erasmus MC, University Medical Centre, Rotterdam, The Netherlands. There are no conflicts of interest.

TRIAL REGISTRATION NUMBER

Registered at the Dutch Trial Register (NTR6854).

Porphyromonas gingivalis-mediated disruption in spiral artery remodeling is associated with altered uterine NK cell populations and dysregulated IL-18 and Htra1

Impaired spiral artery remodeling (IRSA) underpins the great obstetrical syndromes. We previously demonstrated that intrauterine infection with the periodontal pathogen, Porphyromonas gingivalis, induces IRSA in rats. Since our previous studies only examined the end stage of arterial remodeling, the aim of this study was to identify the impact of P. gingivalis infection on the earlier stages of remodeling. Gestation day (GD) 11 specimens, a transition point between trophoblast-independent remodeling and the start of extravillous trophoblast invasion, were compared to late stage GD18 tissues. P. gingivalis was found in decidual stroma of GD11 specimens that already had reduced spiral artery remodeling defined as smaller arterial lumen size, increased retention of vascular smooth muscle, and decreased invasion by extravillous trophoblasts. At GD11, P. gingivalis-induced IRSA coincided with altered uterine natural killer (uNK) cell populations, decreased placental bed expression of interleukin-18 (IL-18) with increased production of temperature requirement A1 (Htra1), a marker of oxidative stress. By GD18, placental bed IL-18 and Htra1 levels, and uNK cell numbers were equivalent in control and infected groups. However, infected GD18 placental bed specimens had decreased TNF + T cells. These results suggest disturbances in placental bed decidual stroma and uNK cells are involved in P. gingivalis-mediated IRSA.

The role of extravillous trophoblasts and uterine NK cells in vascular remodeling during pregnancy

Successful embryo implantation requires both a receptive endometrium and competent blastocysts. After implantation, the maternal decidua undergoes a series of changes, including uterine spiral artery (SA) remodeling to accommodate the fetus and provide nutrients and oxygen for the fetus to survive. Uterine spiral arteries transform from small-diameter, high-resistance arteries to large-diameter and low-resistance arteries during pregnancy. This transformation includes many changes, such as increased permeability and dilation of vessels, phenotypic switching and migration of vascular smooth muscle cells (VSMCs), transient loss of endothelial cells (ECs), endovascular invasion of extravillous trophoblasts (EVTs), and presence of intramural EVT, which are regulated by uterine NK (uNK) cells and EVTs. In this review, we mainly focus on the separate and combined roles of uNK cells and EVTs in uterine SA remodeling in establishing and maintaining pregnancy. New insight into related mechanisms will help us better understand the pathogenesis of pregnancy complications such as recurrent pregnancy loss (RPL) and preeclampsia (PE).

Regulation and Function of Chemokines at the Maternal–Fetal Interface

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

Research progress of placental vascular pathophysiological changes in pregnancy-induced hypertension and gestational diabetes mellitus

The placenta is a vital organ for fetal development, providing the fetus with nutrients, oxygen, and other important factors. Placenta is rich in blood vessels. Abnormal placental vascular function and blood circulation may lead to insufficient blood supply to the fetus in the uterus, leading to serious consequences such as pregnancy complications, fetal distress and even stillbirth. Pregnancy-induced hypertension (PIH) and gestational diabetes mellitus (GDM) are common complications of pregnancy. Recent studies report that pregnancy complications are often accompanied by changes in placental vascular structure and function. What are the physiological characteristics of human placental blood vessels? What are the pathological changes in the state of PIH and GDM? What are the relationships between these pathological changes and the occurrence of these pregnancy complications? Answers to these questions not only increase the understanding of placental vascular characteristics, but also provide important information for revealing the pathological mechanism of PIH and GDM. This article will summarize the research on the pathological changes of placental blood vessels in PIH and GDM, hoping to further unravel the physiological and pathological characteristics of placental blood vessels in the state of PIH and GDM, provide information for guiding clinical treatment for PIH and GDM.

Endometrial thickness is an independent risk factor of hypertensive disorders of pregnancy: a retrospective study of 13,458 patients in frozen-thawed embryo transfers

BACKGROUND

Hypertensive disorders of pregnancy (HDP) are an important cause of maternal and fetal mortality, and its potential risk factors are still being explored. Endometrial thickness (EMT), as one of the important monitoring indicators of endometrial receptivity, has been confirmed to be related to the incidence of HDP in fresh embryo transfer. Our study was designed to investigate whether endometrial thickness is associated with the risk of hypertensive disorders of pregnancy in frozen-thawed embryo transfer (FET).

METHODS

This respective cohort study enrolled 13,458 women who received vitrified embryo transfer and had a singleton delivery in the Reproductive Hospital affiliated to Shandong University from January 2015 to December 2019. We set strict screening criteria and obtained the information from the hospital electronic medical system. Statistical methods including logistic regression analysis, receiver operating characteristic curve and restricted cubic spline were used to evaluate the relationship between endometrial thickness and the incidence of pregnancy-induced hypertension.

RESULTS

The incidences of HDP in a thin endometrial thickness group (< 0.8 cm) and a thick endometrial thickness group (> 1.2 cm) were significantly greater than in a reference group (0.8 cm-1.2 cm) (7.98 and 5.24% vs 4.59%, P <  0.001). A nonlinear relationship between endometrial thickness and risk of hypertensive disorders of pregnancy was examined by restricted cubic spline (P <  0.001). The thin endometrial thickness and thick endometrial thickness groups were significantly associated with the risk of HDP after adjusting for confounding variables by stepwise logistic regression analysis. Subsequently, subgroup logistic regression analysis based on endometrial preparation regimens showed that thin endometria were still significantly associated with a higher morbidity rate in the artificial cycle group, while in the natural cycle group, thick endometria were closely associated with increased morbidity.

CONCLUSION

Our study manifested that both the thin and thick endometria were associated with an increased risk of hypertensive disorders of pregnancy in frozen embryo transfer cycles. Reproductive clinicians should focus on adjusting endometrial thickness in different preparation regimens; and obstetricians should be mindful of the risk of hypertension during pregnancy, when women with thin (< 0.8 cm) or excessively thicker (> 1.2 cm) endometrial thickness achieve pregnancy through frozen-thawed embryo transfer.

MiR-195-5p facilitates the proliferation, migration, and invasion of human trophoblast cells by targeting FGF2

BACKGROUND

Preeclampsia (PE), the most significant adverse exposure to cardiovascular risk during pregnancy, is one of the three major factors contributing to maternal and fetal mortality and the leading cause of preterm birth. Recently, various miRNAs have been reported to participate in PE occurrence and development. Nevertheless, the regulatory impact of miR-195-5p in PE is still indistinct.

METHODS

Quantitative realtime-PCR (qRT-PCR), western blot, and fluorescence in situ hybridization (FISH) assay were performed to examine miR-195-5p and FGF2 expressions in PE serum samples or HTR-8/SVneo and TEV-1 cells. CCK8, flow cytometry, wound scratch, and transwell assays were conducted to determine cell viability, cycle, apoptosis, migration, and invasion. Dual-luciferase reporter assay unveiled the relationship between miR-195-5p and FGF2. Migration-related and invasion-related protein expressions were measured by western blot assay.

RESULTS

miR-195-5p was prominently downregulated while FGF2 was increased in serum samples from PE patients and hypoxia-treated human trophoblast cells. FGF2 was predicted as a downstream target of miR-195-5p and targeted association was verified by dual-luciferase reporter assay. Functional experiments elaborated that miR-195-5p could facilitate trophoblast cell proliferation and metastasis but hinder cell cycle and apoptosis. Inversely, overexpressing of FGF2 could reverse the effects of miR-195-5p on trophoblast cell growth.

DISCUSSION

miR-195-5p was decreased in PE serum samples and cell lines, serving as a potential biomarker in protecting PE exacerbation by targeting FGF2.

Bone marrow stromal cell antigen 2(BST2) suppresses the migration and invasion of trophoblasts in preeclampsia by downregulating matrix metallopeptidase 2(MMP2)

Preeclampsia is a grievous pregnancy-related complication with an incidence of approximately 5∼7% in pregnant women. Placental abnormalities and decreased placental perfusion associated with impaired trophoblast invasion are early pathological findings of preeclampsia. BST2 is a multifunctional transmembrane protein that plays critical roles in physiological and pathological processes, but its impacts and mechanisms of action in preeclampsia are inadequately understood. The aim of this manuscript was to investigate the functional impacts of BST2 and MMP2 on the biological behavior of trophoblast cells in preeclampsia. The expression of these proteins and their genes was analyzed by qRT-PCR, western blotting and immunohistochemistry. The results showed that the expression of BST2 and MMP2 was significantly downregulated in preeclampsia. The migration and invasion capacities of HTR-8/SVneo and JAR cells with overexpression or knockdown of BST2 were detected by wound healing assay and Transwell assays. It was found that BST2 overexpression could up-regulate MMP2 expression, and enhance the migration and invasion capacity of HTR-8/SVneo and JAR cells. BST2 knockdown could reverse these effects. MMP2 knockdown could downregulate the invasion capacity of HTR-8/SVneo cells, and MMP2 overexpression reversed these effects. Pearson correlation analysis demonstrated that the expression of MMP2 and BST2 were positively correlated. These results indicate that the downregulation of BST2 lowers MMP2 expression and restraint trophoblast functions, which probably explain its role in the pathogenesis of preeclampsia.

Multiomics Studies Investigating Recurrent Pregnancy Loss: An Effective Tool for Mechanism Exploration

Patients with recurrent pregnancy loss (RPL) account for approximately 1%-5% of women aiming to achieve childbirth. Although studies have shown that RPL is associated with failure of endometrial decidualization, placental dysfunction, and immune microenvironment disorder at the maternal-fetal interface, the exact pathogenesis remains unknown. With the development of high-throughput technology, more studies have focused on the genomics, transcriptomics, proteomics and metabolomics of RPL, and new gene mutations and new biomarkers of RPL have been discovered, providing an opportunity to explore the pathogenesis of RPL from different biological processes. Bioinformatics analyses of these differentially expressed genes, proteins and metabolites also reflect the biological pathways involved in RPL, laying a foundation for further research. In this review, we summarize the findings of omics studies investigating decidual tissue, villous tissue and blood from patients with RPL and identify some possible limitations of current studies.

Hypoxia-induced polarization of M2 macrophages and CCL5 secretion promotes the migration and invasion of trophoblasts

In the early stage of pregnancy, hypoxia in the placenta is of great significance to the migration and invasion of trophoblasts. In addition, changes to the polarity and activity of macrophages can affect embryo implantation, trophoblast migration and invasion, and vascular remodeling by affecting cytokine secretion. However, the mechanism of the effects of hypoxic conditions in the placenta on trophoblasts remains unknown. We used gene knockdown on macrophages, and drug treatment on trophoblasts, and cultured them under hypoxic and normoxic conditions. The cells were then subjected to wound healing assays, Transwell cell invasion experiments, quantitative real-time reverse transcription PCR, western blotting, and immunofluorescence. The polarization of macrophages in each group, the migration and invasion ability of trophoblasts, and changes to the phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K)/protein kinase B (AKT) signaling pathway were detected. Hypoxic conditions induce M2 polarization of macrophages. The conditioned medium from macrophages under hypoxic conditions increased the migration and invasion of trophoblasts, and enhanced the levels of phosphorylated (p)-PI3K and p-AKT in trophoblasts. After CCL5 knockdown in macrophages, the ability of conditioned medium from macrophages cultured under hypoxic conditions to promote the migration and invasion of trophoblasts was weakened significantly. The use of PI3K/AKT signaling pathway agonists could reverse the attenuation effect caused by CCL5 knockdown.

Current understanding in deciphering trophoblast cell differentiation during human placentation

The placenta is a unique organ that forms during gestation and supports fetus survival and communication with the mother. However, of such an arguably essential organ for a successful pregnancy, our knowledge is limited. New progress has been made for human placenta study in recent years. We herein summarize the current understanding of human placental trophoblast differentiation and the molecules that govern trophoblast cell lineage specification. More importantly, the powerful tools for placental studies are also explained, such as human trophoblast stem cells (hTSCs), 3-dimensional (3D) trophoblast organoids, engineering-based placental devices, and single-cell RNA sequencing (sc-RNAseq). These advances have brought us new insights into placental development and provided multiple investigation strategies for deciphering molecular mechanisms.

The Novel Peptide AEDPPE Alleviates Trophoblast Cell Dysfunction Associated With Preeclampsia by Regulating the NF-κB Signaling Pathway

Background: Preeclampsia (PE) is a serious risk to the health of pregnant women and fetuses during pregnancy, and there is no effective treatment for this condition. Although many reports have confirmed the therapeutic effects of peptides in diseases, the role of peptides in PE remains poorly understood.

Methods: A differentially expressed peptide in PE (AEDPPE) is derived from heat-shock protein beta-1 (HSPB1), amino acids 100 to 109 (DVNHFAPDEL), which we identified in a previous study. We synthesized AEDPPE and investigated its effect on HTR-8/SVneo cell function using a Cell Counting Kit-8, flow cytometric assay, and Transwell and wound-healing assays. Quantitative reverse transcription-PCR and ELISA were used to determine cytokine expression. Pull-down assay, mass spectrometry, Western blot analysis, and immunofluorescence were used to explore the potential targets and signaling pathways regulated by AEDPPE. Finally, we assessed the effect of AEDPPE in the lipopolysaccharide (LPS)-induced PE-like rat model.

Results: AEDPPE significantly promoted the migration and invasion of HTR-8/SVneo cells, and it decreased the expression of interleukins 1 beta (IL-1β), interleukin 6 (IL-6), and interleukin 8 (IL-8). These functions performed by AEDPPE remained evident after injury to HTR-8/SVneo cells with tumor necrosis factor-alpha (TNF-α), and AEDPPE reversed the elevated sFlt-1/PlGF ratio induced by TNF-α. AEDPPE may exert these biological effects by binding to heat-shock protein 90β (HSP 90β) and, thus, affect the NF-κB signaling pathway. In an LPS-induced PE-like rat model, AEDPPE significantly improved PE symptoms and fetal rat outcomes.

Conclusion: Our study showed that AEDPPE enhanced trophoblast migration and invasion and reduced inflammatory cytokine expression, and we hypothesized that these actions involved the NF-κB signaling pathway. The use of AEDPPE may thus develop into a novel modality in the treatment of PE.

Intersection of regulatory pathways controlling hemostasis and hemochorial placentation

Hemochorial placentation is characterized by the development of trophoblast cells specialized to interact with the uterine vascular bed. We utilized trophoblast stem (TS) cell and mutant rat models to investigate regulatory mechanisms controlling trophoblast cell development. TS cell differentiation was characterized by acquisition of transcript signatures indicative of an endothelial cell-like phenotype, which was highlighted by the expression of anticoagulation factors including tissue factor pathway inhibitor (TFPI). TFPI localized to invasive endovascular trophoblast cells of the rat placentation site. Disruption of TFPI in rat TS cells interfered with development of the endothelial cell-like endovascular trophoblast cell phenotype. Similarly, TFPI was expressed in human invasive/extravillous trophoblast (EVT) cells situated within first-trimester human placental tissues and following differentiation of human TS cells. TFPI was required for human TS cell differentiation to EVT cells. We next investigated the physiological relevance of TFPI at the placentation site. Genome-edited global TFPI loss-of-function rat models revealed critical roles for TFPI in embryonic development, resulting in homogeneous midgestation lethality prohibiting analysis of the role of TFPI as a regulator of the late-gestation wave of intrauterine trophoblast cell invasion. In vivo trophoblast-specific TFPI knockdown was compatible with pregnancy but had profound effects at the uterine-placental interface, including restriction of the depth of intrauterine trophoblast cell invasion while leading to the accumulation of natural killer cells and increased fibrin deposition. Collectively, the experimentation implicates TFPI as a conserved regulator of invasive/EVT cell development, uterine spiral artery remodeling, and hemostasis at the maternal-fetal interface.

Maternal platelets at the first trimester maternal-placental interface - Small players with great impact on placenta development

In human pregnancy, maternal platelet counts decrease with each trimester, reaching a reduction by approximately ten percent at term in uncomplicated cases and recover to the levels of the non-pregnant state a few weeks postpartum. The time when maternal platelets start to occur in the early human placenta most likely coincides with the appearance of loosely cohesive endovascular trophoblast plugs showing capillary-sized channels by mid first trimester. At that time, platelets accumulate in intercellular gaps of anchoring parts of trophoblast columns and start to adhere to the surface of placental villi and the chorionic plate. This is considered as normal process that contributes to placenta development by acting on both the extravillous- and the villous trophoblast compartment. Release of platelet cargo into intercellular gaps of anchoring cell columns may affect partial epithelial-to-mesenchymal transition and invasiveness of extravillous trophoblasts as well as deposition of fibrinoid in the basal plate. Activation of maternal platelets on the villous surface leads to perivillous fibrin-type fibrinoid deposition, contributing to the shaping of the developing placental villi and the intervillous space. In contrast, excess platelet activation at the villous surface leads to deregulation of the endocrine activity, sterile inflammation and local apoptosis of the syncytiotrophoblast. Platelets and their released cargo are adapted to pregnancy, and may be altered in high-risk pregnancies. Identification of different maternal platelet subpopulations, which show differential procoagulant ability and different response to anti-platelet therapy, are promising new future directions in deciphering the role of maternal platelets in human placenta physiology.

Detection and significance of main anchoring villus in early pregnancy

OBJECTIVE

To find and explore the relationship among the length of the embryo's main anchoring villus and the week of gestation, embryonic crown-rump length (CRL), and maternal blood human chorionic gonadotropin (hCG) during early pregnancy using ultrasound.

METHODS

A total of 108 women with singleton pregnancies underwent ultrasound examination of the fetus during the early months of their pregnancy (5⁺⁵ -13⁺⁶  weeks of pregnancy). The main anchoring villus was detected using HD-Flow and SlowflowHD mode ultrasound. The detection rate and length of the main anchoring villus were recorded. The correlations among main anchoring villus with gestational weeks, CRL, and blood hCG were obtained.

RESULTS

The main anchoring villus was detected in all women (108/108). It could be found throughout the early gestational weeks from as early as 4⁺⁶  weeks. The length of the main anchoring villus increased with gestational age, and was positively correlated with CRL and the logarithm of hCG (P < 0.05).

CONCLUSION

Our results showed that the detection rate of the main anchoring villus was 100% and the length of the main anchoring villus was correlated with gestational week, CRL, and blood hCG. The main anchoring villus could represent where the embryo implanted.

Evaluation of Placentation and the Role of the Aryl Hydrocarbon Receptor Pathway in a Rat Model of Dioxin Exposure

BACKGROUND

Our environment is replete with chemicals that can affect embryonic and extraembryonic development. Dioxins, such as 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), are compounds affecting development through the aryl hydrocarbon receptor (AHR).

OBJECTIVES

The purpose of this investigation was to examine the effects of TCDD exposure on pregnancy and placentation and to evaluate roles for AHR and cytochrome P450 1A1 (CYP1A1) in TCDD action.

METHODS

Actions of TCDD were examined in wild-type and genome-edited rat models. Placenta phenotyping was assessed using morphological, biochemical, and molecular analyses.

RESULTS

TCDD exposures were shown to result in placental adaptations and at higher doses, pregnancy termination. Deep intrauterine endovascular trophoblast cell invasion was a prominent placentation site adaptation to TCDD. TCDD-mediated placental adaptations were dependent upon maternal AHR signaling but not upon placental or fetal AHR signaling nor the presence of a prominent AHR target, CYP1A1. At the placentation site, TCDD activated AHR signaling within endothelial cells but not trophoblast cells. Immune and trophoblast cell behaviors at the uterine-placental interface were guided by the actions of TCDD on endothelial cells.

DISCUSSION

We identified an AHR regulatory pathway in rats activated by dioxin affecting uterine and trophoblast cell dynamics and the formation of the hemochorial placenta. https://doi.org/10.1289/EHP9256.