Trimester Placenta Research Articles

720 Comparing transcriptional signatures of fetal hofbauer cells derived from bulk versus single-Cell RNA sequencing approaches

Fetal Hofbauer Cells (HBC) play an instrumental role in the maintenance of a healthy pregnancy and in response to infection. Single-cell RNA sequencing (scRNAseq) has recently identified potential markers of HBC (Vento-Tormo, Nature, 2018). However, it is unknown whether these transcriptional signatures are congruent with profiles obtained from bulk RNA sequencing (bRNAseq) of purified cell populations. Here we compared the results from these two different approaches to transcriptomic studies. This is a comparative study of results from a publicly available scRNAseq database that analyzed first trimester placentas and bRNAseq data generated by our group analyzing term placentas from normal pregnancies. In the bRNAseq analysis, maternal intervillous monocytes (MIM) and HBC were purified using targeted isolation techniques. Differentially expressed genes in paired samples were identified using LIMMA and compared to a list of 30 proposed HBC markers. Transcript levels were normalized against the mean expression in MIM for each gene to determine relative gene expression; normalized expression values were compared with the 30 markers. HBC:MIM expression ratios were also calculated in paired samples. 19 of 30 (63%) HBC markers defined by scRNAseq were also identified by bRNAseq (adjusted p-value<0.01). Hierarchical clustering demonstrated that HBC and MIM samples clustered separately and that all markers were more highly expressed in HBC, with the exception of DAB2 (Fig 1). Analysis of HBC:MIM expression ratios in paired samples, also demonstrated low relative expression of DAB2 in HBC. ATP1B1, LGMN, NINJ1, and EGFL7 showed higher expression in HBC which was consistent between patient samples (Fig 2). Results from scRNAseq and bRNAseq approaches showed >60% concordance in the identification of HBC markers, despite differences in gestational age and approach. Future studies are needed to validate the use of these potential biomarkers of HBCs, which will serve as important tools in understanding the role of these cells in placental disease.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

362 Functional MRI to assess third trimester placental oxygenation

Higher R2* relaxation rates in functional magnetic resonance imaging (fMRI) reflect increased deoxygenated hemoglobin content and perhaps diminished oxygen exchange. We hypothesize that higher R2* relaxation rates may be found in women with obesity (OB) or diabetes (DM) as compared to normal weight women (NL). We aim to compare R2* relaxation rates in third trimester placentas of OB, DM and NL patients. We performed a prospective cohort pilot study using fMRI to evaluate placentas at 30-34 weeks gestation among patients with pre-pregnancy BMI ≥ 30 kg/m2 (OB), those with Type 1 or Type 2 DM diagnosed prior to pregnancy or in the first trimester (DM), and patients with pre-pregnancy BMI 18.5-24.9 kg/m2 without comorbidities (NL). HASTE T2 sequence was utilized to evaluate placental architecture and to select 1 cm2 regions of interest (ROI) within 3 centrally located lobules. ROI were selected at both the center and periphery of each lobule. Once ROI were identified via HASTE T2 images, the same ROI on the corresponding R2* maps were evaluated and relaxation rates were compared across groups. Primary outcome was mean R2* relaxation rates. Maternal demographic, clinical outcomes and relaxation rates were compared using ANOVA followed by Dunnett analysis. 5 OB, 3 DM, and 6 NL patients were included. Age, parity, race and ethnicity were similar across groups (Table 1). OB and DM had higher pre-pregnancy BMI (36.8±3.6 kg/m2 and 32.8±3=2.9 kg/m2, respectively) compared to NL (22.6±1.8 kg/m2, p < 0.001). Obstetric outcomes including gestational age at delivery and birthweight were similar (Table 1). Mean R2* relaxation rate was similar at the central portions of placental lobules across groups (Figure 1). Mean R2* relaxation rate at the peripheral portions of placental lobules was higher in OB (97.7±51.5, p = 0.003) and DM (66.3±39.4, p = 0.333) as compared to NL (52.3±32.0, Figure 1). R2* relaxation rates are higher at the periphery of central lobules in OB and DM patients compared to NL patients and may imply diminished placental oxygen exchange relative to NL.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

648 Utilizing primary human tissue/cell models to assess for pesticide-induced placental toxicity

Chorionic villi serve as the primary interface between mother and fetus. Dysfunction at this interface is implicated in pregnancy complications. Pesticides are widely used in agriculture and vector control, but the full impact on human pregnancy is unknown. Specific pesticides such as organophosphate pesticides (OPs) are suspected to target the developing central nervous system and placenta. We aimed to leverage ex vivo models of the human placenta (primary chorionic villous explants and isolated cytotrophoblasts (CTBs)) for in vitro studies of toxicological agents. Isolated CTBs from 2nd trimester placentas were exposed to 9 diverse pesticides at 5 concentrations and compared to vehicle (0.1% DMSO) and media-only controls. At 24h, viability and cell death were assayed by neutral red lysosomal uptake or lactate dehydrogenase activity, respectively. Benchmark concentrations (BMC10) of a 10% change in cytotoxicity were identified to assess relative potencies. Human chorionic villi explants dissected from placentas were exposed to naled or vehicle for 24h. After exposure, 1st trimester villi were evaluated by gross morphology and 2nd trimester villi by histopathology and immunofluorescence. Sections were scored by 2 blind evaluators for syncytiotrophoblast (STB) denudation, quantified by ImageJ analysis. We used ANOVA and Tukey’s test to determine significant changes between groups. We observed concentration-dependent cytotoxicity with the three OPs (naled, dichlorovos and malathion) in CTBs (p<0.05; Figure 1). Naled was the most toxic pesticide. Gross morphologic evaluation of naled-exposed villi showed frayed appearance and impaired vascularity compared to the control groups. Naled-exposed explants displayed a ∼4-fold increase in STB denudation compared with media-only or vehicle controls (p<0.001, Figure 2). Our results suggest that naled, an OP commonly-used in agriculture and mosquito control is particularly toxic in two human placental models. We demonstrate that primary cell/tissue models can be used to evaluate placental toxicity of pesticide compounds.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Syncytins expressed in human placental trophoblast

Three versions of syncytiotrophoblast exist in the human placenta: an invasive type associated with the implanting conceptus, non-invasive villous type of definitive placenta, and placental bed giant cells. Syncytins are encoded by modified env genes of endogenous retroviruses (ERV), but how they contribute functionally to placental syncytial structures is unclear. A minimum of eight genes (ERVW1, ERVFRD-1, ERVV-1, ERVV-2, ERVH48-1, ERVMER34-1, ERV3-1, & ERVK13-1) encoding syncytin family members are expressed in human trophoblast, the majority from implantation to term. ERVW1 (Syncytin 1) and ERVFRD-1 (Syncytin 2) are considered the major fusogens, but, when the expression of their genes is analyzed by single cell RNAseq in first trimester placenta, their transcripts are distinctly patterned and also differ from those of their proposed binding partners, SLC1A5 and MFSD2A, respectively. ERVRH48-1 (suppressyn or SUPYN) and ERVMER34-1 are probable negative regulators of fusion and co-expressed, primarily in cytotrophoblast. The remaining genes and their products have been little studied. Syncytin expression is a feature of placental development in almost all eutherian mammals studied, in at least one marsupial, and in viviparous lizards, which lack the trophoblast lineage. Their expression has been inferred to be essential for pregnancy success in the mouse. All the main human ERV genes arose following independent retroviral insertion events, none of which trace back to the divergence of eutherians and metatherians (marsupials). While syncytins may be crucial for placental development, it seems unlikely that they helped orchestrate the divergence of eutherians and marsupials.

Discovery of inverted discordant p57 expression in random clusters of dysmorphic chorionic villi of third trimester placentas suggests a more common occurrence of such phenomenon than initially described

IntroductionInverted discordant p57 expression in chorionic villi, characterized by a loss of nuclear staining in cytotrophoblast with retained staining in villous stromal cells, is rarely described. Following an incidental finding of such peculiar staining pattern in rare clusters of dysmorphic chorionic villi (DCV) in a perinatal autopsy case, we reviewed our archived cases of third trimester placentas with DCV to systematically analyze these curious foci. MethodsHistopathological features and p57 expression of 26 placentas with DCV were carefully studied by light microscopy and p57 immunohistochemistry. p57 pattern of expression was correlated with a comprehensive list of maternal, fetal, and placental features to reveal potential associations. ResultsInverted discordant p57 expression was observed in 17/26 (65.4%) cases, encompassing all cases with aberrant p57 immunostaining in this series. Among the many features investigated, only the focality (occurring as a single focus) of DCV (Fisher's exact test, p = 0.008) and small cluster size of ≤30 villi (Fisher's exact test, p = 0.034) correlated significantly with inverted discordant p57 staining. Other common features of DCV with inverted discordant p57 expression include larger villous size compared with surrounding tertiary villi (13/17, 76.4%), prominent but not hyperplastic and focally to moderately hyperplastic syncytiotrophoblast (17/21, 80.9%), abnormal shapes/irregular contours (17/22, 77.3%), and markedly hypovascular villous stroma (11/17, 64.7%). No distinctive maternal or fetal features were observed. DiscussionInverted discordant p57 expression in DCV of third trimester placentas is likely underreported, and might not be an unusual occurrence outside of suspected molar specimens.

Morphometric analysis of Hofbauer cells in normal placenta and chorioamnionitis in humans.

Hofbauer cells are macrophages residing in the stroma of placental villi and play a number of roles during normal pregnancy, as well as pathological conditions. A morphometric analysis of Hofbauer cells, in particular to investigate the number of cells, their size and shape in samples of normal human placenta from 1st trimester, term and with chorioamnionitis was performed. Tissue samples were immunostained for CD206 antigen and evaluated using ImageJ software. We detected significant changes in number and morphology of HBCs between normal placenta and placenta with chorioamnionitis samples. In chorioamnionitis, the cells were unevenly distributed within the villi, generally present in higher numbers, larger and more elongated than those in normal 1st trimester and term placenta.

The uteroplacental contact zone cytokine influence on NK cell cytotoxicity to trophoblasts

Objective The present study was to estimate the role of cytokines for trophoblast death in NK cells presence. Methods This study involves assessment of NK-92 line NK cell cytotoxic activity against JEG-3 line cells, in presence of cytokines. We also assessed the effect of secretory placenta products on NK cell cytotoxic activity toward JEG-3 line cells. Results Uteroplacental contact zone cytokines are able to enhance trophoblast mortality both by themselves in case of IL-1β, IL-6, IFNγ, IL-4, TGFβ, bFGF, and also through increasing the cytotoxic potential of NK cells in case of IL-1β, IFNγ, IL-8, TGFβ, and GM-CSF. PLGF decreases NK cell cytotoxicity for trophoblasts. Secretory products of first trimester placenta enhance NK cell cytotoxic potential for trophoblasts. Conclusions Cytokines of the uteroplacental contact zone can appear a mechanism ensuring trophoblast mortality dynamics throughout pregnancy.

The association between first trimester placental biomarkers and placental lesions of maternal vascular malperfusion

IntroductionAbnormal levels of first trimester placental biomarkers are associated with the development of placental syndrome (PS). However, prediction performance is moderate, possibly explained by the clinical heterogeneity of PS. Aim of this study is to investigate the association between first trimester biomarkers and the presence of maternal vascular malperfusion (MVM), as a marker for placental insufficiency. MethodsThis retrospective study included 195 women with available first trimester blood sample and placenta histological sections for examination at the Maastricht University Medical Centre. Women were divided into 4 groups, based on the presence of having MVM lesions and/or PS. Levels of PAPP-A, PlGF and sFlt-1 were measured and MVM lesions were classified according to the Amsterdam Placental Workshop Group Consensus Statement. ResultsMVM occurrence was observed in 32% of the uncomplicated pregnancies. Women with MVM (regardless of the PS) had lower levels of PAPP-A (p = 0.038) and sFLt-1 (p = 0.006), and a non-significant trend for lower PlGF and sFlt-1/PlGF ratio compared to women without MVM. Low PAPP-A levels individually and in combination with the presence of PS was significantly associated with MVM lesions (aOR = 3.0 and 6.1, respectively), as did the combination of low PlGF levels and PS (aOR = 4.6). In women with PS, having MVM increased the incidence of fetal growth restriction, small for gestational age neonates, lower birthweight and adverse neonatal outcome. DiscussionOur findings suggest that MVM lesions were found to be associated with increased obstetric risks due to early placental dysfunction that can potentially be predicted by the use of first trimester biomarkers.

Histopathology of Third Trimester Placenta from SARS-CoV-2-Positive Women

Background: This study aims to investigate whether maternal SARS-CoV-2 status affects placental pathology. Methods: A retrospective case-control study was conducted by reviewing charts and slides of placentas delivered between April 1 to July 24, 2020. Clinical history of “COVID-19” was searched in Pathology Database (CoPath). Controls were matched with SARS-CoV-2-negative women with singleton deliveries in the 3rd-trimester. Pathological features were extracted from placental pathology reports. Results: Twenty-one 3rd trimester placentas from SARS-CoV-2-positive women were identified and compared to 20 placentas from SARS-CoV-2-negative women. There were no significant differences in individual or group gross or microscopic pathological features. Within the SARS-CoV-2+ group, there are no differences between symptomatic and asymptomatic women. Conclusion: Placentas from SARS-CoV-2-positive women do not demonstrate a specific pathological pattern. Pregnancy complicated with COVID-19 during the 3rd trimester does not have a demonstrable effect on placental structure and pathology.

Primary Cilia in Trophoblastic Cells: Potential Involvement in Preeclampsia.

The pathogenesis of preeclampsia, a pregnancy-related disease, is not completely understood. The primary cilium transduces a diverse array of signaling pathways important for vital cellular activities. Primary cilia were reported to facilitate trophoblastic cell invasion. We hypothesized their further functions in trophoblasts and were interested in related molecular mechanisms. We systematically examined the presence, length and percentage of the primary cilium, its mediated signal transduction, and its connection to trophoblast function. Various cellular and molecular methods were used including immunofluorescence staining, spheroid formation, gene analysis, invasion and tube formation assays with trophoblastic cell lines, primary trophoblasts, and placental tissues. We show that primary cilia are present in various trophoblastic cell lines derived from first trimester placentas. Cilia are also observable in primary trophoblasts, though in a small quantity. Importantly, primary cilia are shortened in trophoblastic cells derived from preeclamptic placentas. Mechanistically, interleukin-6, tumor necrosis factor-α or sera from patients with preeclampsia are able to reduce the length of primary cilia and impair the important sonic hedgehog signaling pathway. Functionally, trophoblastic cells with defective cilia display severe failures in their key functions, like migration, invasion and tube formation, also observed in trophoblastic cells depleted of the intraflagellar transport protein 88. This is accompanied by reduced gene expression of matrix metallopeptidases, vascular endothelial growth factor, and placental growth factor. This work highlights the significance of primary cilia in the functions of trophoblastic cells. Dysfunctional cilia may lead to compromised migration, invasion, and endothelial remodeling of trophoblastic cells, contributing to the development of preeclampsia.

Single Dose Methotrexate in Successful Evacuation of Second Trimester Placenta Accreta

Morbidly adherent placenta is a serious and life-threatening condition. High index of suspicion for placentaaccreta can save patient from undergoing hysterectomy. Timely and appropriate treatment modality is keyin reducing morbidity of the patient Reporting herewith a case of 22-24 weeks intrauterine fetal demisein a primigravida patient who was diagnosed with Placenta accreta. Ultrasonography and MRI confirmedthe diagnosis. Primigravida with no live issue, no active bleeding and stable vital parameters favoredthe option of conservative management in the form of “single dose methotrexate regime”. Patient wasthen given Injection methotrexate 50 mg IM on day 1. Regularly monitored with CBC(complete bloodcount),LFT(Liver Function Test),KFT(kidney Function Test), beta HCG, USG and pelvic doppler. On day 7piecemeal removal of complete placenta accrete was successful under USG guidance.

Dynamics of Tryptophan Metabolic Pathways in Human Placenta and Placental-Derived Cells: Effect of Gestation Age and Trophoblast Differentiation.

L-Tryptophan is an essential amino acid and a precursor of several physiologically active metabolites. In the placenta, the serotonin and kynurenine metabolic pathways of tryptophan metabolism have been identified, giving rise to various molecules of neuroactive or immunoprotective properties, such as serotonin, melatonin, kynurenine, kynurenic acid, or quinolinic acid. Current literature suggests that optimal levels of these molecules in the fetoplacental unit are crucial for proper placenta functions, fetal development and programming. Placenta is a unique endocrine organ that, being equipped with a battery of biotransformation enzymes and transporters, precisely orchestrates homeostasis of tryptophan metabolic pathways. However, because pregnancy is a dynamic process and placental/fetal needs are continuously changing throughout gestation, placenta must adapt to these changes and ensure proper communication in the feto-placental unit. Therefore, in this study we investigated alterations of placental tryptophan metabolic pathways throughout gestation. Quantitative polymerase chain reaction (PCR) analysis of 21 selected genes was carried out in first trimester (n = 13) and term (n = 32) placentas. Heatmap analysis with hierarchical clustering revealed differential gene expression of serotonin and kynurenine pathways across gestation. Subsequently, digital droplet PCR, Western blot, and functional analyses of the rate-limiting enzymes suggest preferential serotonin synthesis early in pregnancy with a switch to kynurenine production toward term. Correspondingly, increased function and/or protein expression of serotonin degrading enzyme and transporters at term indicates efficient placental uptake and metabolic degradation of serotonin. Lastly, gene expression analysis in choriocarcinoma-derived cell lines (BeWo, BeWo b30, JEG-3) revealed dissimilar expression patterns and divergent effect of syncytialization compared to primary trophoblast cells isolated from human term placentas; these findings show that the commonly used in vitro placental models are not suitable to study placental handling of tryptophan. Altogether, our data provide the first comprehensive evidence of changes in placental homeostasis of tryptophan and its metabolites as a function of gestational age, which is critical for proper placental function and fetal development.

Which second trimester placenta previa remains a placenta previa in the third trimester: A prospective cohort study

ObjectiveThe far majority of women with a placenta previa in the second trimester will no longer have a placenta that overlies the internal os in the third trimester. Women with a placenta previa in the third trimester are at risk for complication such as preterm birth and blood loss. Four counselling purposes we aim to identify which women with a second trimester placenta previa have a low-risk and a high-risk for persistence of the placenta previa. Study designA prospective cohort study of women with a placenta previa in the second trimester between 2014 and 2019. The odds for having a placenta previa in the third trimester were calculated for different baseline characteristics. Multilevel likelihood ratios for ranges of the placenta overlying the internal os in the second trimester and the corresponding ROC curve were calculated to identify the optimal cut-off values. ResultsWe included 313 women with a placenta previa in the second trimester. The placenta was more frequently located on the posterior wall (62 %) than on the anterior wall (38 %). At evaluation in the third trimester, 37 women (14 %) still had a placenta previa. Women with a larger distance of the placenta overlying the internal os, women having a previous cesarean delivery and women after a conception with assisted reproductive technique had a significant higher risk of placenta previa persistence (p-values <0.001). Women with a placenta overlying less than 14 mm can be considered as low-risk, indicated by a likelihood ratio of 0. Women with a placenta with more than 55 mm overlap can be considered as high-risk, indicated a the likelihood ratio of ∞. ConclusionThe majority of the second trimester placenta previa will no longer overly the internal os in the third trimester. Placenta previa persistence is associated with the distance overlying the internal os, a previous cesarean delivery and assisted reproductive techniques. In the second trimester, women can be identified as low-risk and high-risk for persistence of placenta previa. This can be used for risk stratification, counselling and individualized care for women with a second trimester placenta previa.

A structured review of placental morphology and histopathological lesions associated with SARS-CoV-2 infection

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a novel coronavirus, was first identified after a cluster of cases in Wuhan, China in December 2019. Whether vertical transmission or placental pathology might occur following maternal infection during pregnancy remains unknown. This review aimed to summarise all studies that examined the placenta or neonates following infection with SARS-CoV-2, or closely related highly pathogenic coronavirus (SARS-CoV-1, or the Middle East respiratory syndrome coronavirus (MERS-CoV)). Structured literature searches found 50 studies that met the inclusion criteria.Twenty studies reported placental histopathology findings in third trimester placentas following maternal SARS-CoV-2 infection. Using the Amsterdam Consensus criteria to categorise the histopathology results, evidence of both fetal vascular malperfusion (35.3% of cases; 95% Confidence Interval (CI) 27.7–43.0%) and maternal vascular malperfusion (46% of cases; 95% CI 38.0–54.0%) were reported, along with evidence of inflammation in the placentas (villitis 8.7% cases, intervillositis 5.3% of cases, chorioamnionitis 6% of cases). The placental pathologies observed in SARS-CoV-2 were consistent with findings following maternal SARS-CoV-1 infection. Of those tested, a minority of neonates (2%) and placental samples tested positive for SARS-CoV-2 infection (21%).Limited conclusions can be drawn about the effect of maternal SARS-CoV-2 infection on placental pathology as most lack control groups and the majority of reports followed third trimester infection. Collaboration to maximise the number of samples examined will increase the reliability and generalisability of findings. A better understanding of the association between maternal SARS-CoV-2 infection and placental pathology will inform maternity care during the coronavirus pandemic.

Insight into the expression of RIG-I-like receptors in human third trimester placentas following ex vivo cytomegalovirus or vesicular stomatitis virus infection

A viral infection is detected through germline-encoded pattern-recognition receptors (PRRs) leading to the production of interferons (IFNs) and proinflammatory cytokines. The objective of this study was to investigate the expression of retinoic acid-inducible gene-I (RIG-I)-like receptors (RLRs) in response to viral infection and the selected cytokine responses in the human term placenta. Placental villi and decidual explants were infected with human cytomegalovirus (CMV) or vesicular stomatitis virus (VSV) and cultured ex vivo to study viral infection. To evaluate DDX58 (RIG-I), IFIH1 (MDA5), and DHX58 (LGP2) expression, quantitative real-time PCR (qRT-PCR) was used. The expression of RLRs was detected by Western blotting. Cytokine and chemokine production, as well as RLR protein levels, were quantified using ELISA. The increased expression of both RIG-I and MDA5 and the enhanced secretion of IFN-ß were observed in response to VSV infection compared to mock-infected tissues. CMV infection resulted in higher transcript levels of DDX58 and IFIH1, while no changes in the cytokine production were observed. Our results indicate that RIG-I and MDA5 are specifically expressed in chorionic villi and deciduae in response to VSV infection. These findings suggest that RLRs may play a key role in pathogen recognition and the immune response against intrauterine viral transmission.

Stomatin-like protein 2 (SLP2) regulates the proliferation and invasion of trophoblast cells by modulating mitochondrial functions

IntroductionStomatin-like protein 2 (SLP2) is highly expressed in human first trimester trophoblast cells, but its functions in placental morpho-physiology remain unknown. This study aimed to determine the role of SLP2 in the proliferation and invasion of human first trimester trophoblast cells. MethodsImmunofluorescence was used to determine the expression and localization of SLP2 in normal and miscarriage human first trimester placenta. Western blot was used to determine the expression of SLP2, PCNA, Cyclin D3, N-cadherin, Vimentin, PGC1α and PPARα in HTR-8/SVneo cells. SLP2 was knocked down in the HTR-8/SVneo cells by using si-Slp2. Wound healing and migration assays were used to determine the effect of SLP2 knockdown on the migration and invasion in the HTR-8/SVneo cells. Mitochondrial membrane potential, reactive oxygen species (ROS), ATP production and biogenesis were measured to assess the effects of SLP2 knockdown on mitochondrial functions. ResultSLP2 was strongly expressed in the cytotrophoblasts (CTB), syncytiotrophoblast (STB) and extravillous trophoblasts (EVT) of normal pregnancy placenta as compared to miscarriage placenta. SLP2 was highly expressed in the invasive EVT cell lines, HTR-8/SVneo and HPT-8 compared to the CTB cell line JAR. Knockdown of SLP2 significantly inhibited the migration and invasion of HTR-8/SVneo cells and placental villous explants, and repressed mitochondrial biogenesis and functions in HTR-8/SVneo cells. DiscussionSilencing of SLP2 inhibited the proliferation, migration and invasion of HTR-8/SVneo cells via the impairment of mitochondrial functions. This indicates that the downregulation of SLP2 in miscarriage placenta could be part of the pathogenesis and pathophysiology of the disease.

Sexually Dimorphic Crosstalk at the Maternal-Fetal Interface.

Crosstalk through receptor ligand interactions at the maternal-fetal interface is impacted by fetal sex. This affects placentation in the first trimester and differences in outcomes. Sexually dimorphic signaling at early stages of placentation are not defined. Investigate the impact of fetal sex on maternal-fetal crosstalk. Receptors/ligands at the maternal-fetal surface were identified from sexually dimorphic genes between fetal sexes in the first trimester placenta and defined in each cell type using single-cell RNA-Sequencing (scRNA-Seq). Academic institution. Late first trimester (~10-13 weeks) placenta (fetal) and decidua (maternal) from uncomplicated ongoing pregnancies. Transcriptomic profiling at tissue and single-cell level; immunohistochemistry of select proteins. We identified 91 sexually dimorphic receptor-ligand pairs across the maternal-fetal interface. We examined fetal sex differences in 5 major cell types (trophoblasts, stromal cells, Hofbauer cells, antigen-presenting cells, and endothelial cells). Ligands from the CC family chemokine ligand (CCL) family were most highly representative in females, with their receptors present on the maternal surface. Sexually dimorphic trophoblast transcripts, Mucin-15 (MUC15) and notum, palmitoleoyl-protein carboxylesterase (NOTUM) were also most highly expressed in syncytiotrophoblasts and extra-villous trophoblasts respectively. Gene Ontology (GO) analysis using sexually dimorphic genes in individual cell types identified cytokine mediated signaling pathways to be most representative in female trophoblasts. Upstream analysis demonstrated TGFB1 and estradiol to affect all cell types, but dihydrotestosterone, produced by the male fetus, was an upstream regulator most significant for the trophoblast population. Maternal-fetal crosstalk exhibits sexual dimorphism during placentation early in gestation.

Matrix metalloproteinase 15 plays a pivotal role in human first trimester cytotrophoblast invasion and is not altered by maternal obesity

Adequate anchoring of the placenta in the uterus through invasion of first trimester cytotrophoblasts (CTB) is required for a successful pregnancy. This process is mediated by matrix metalloproteinases (MMPs) and regulated by the maternal environment. Obesity is known to alter the intrauterine milieu and has been related to impaired invasion. We hypothesized that placental MMP15, a novel membrane‐type MMP, is involved in CTB invasion and regulated by maternal obesity in early pregnancy. Thus, in this study MMP15 was immunolocalized to invasive extravillous and interstitial CTB. MMP15 silencing in chorionic villous explants using two different siRNAs reduced trophoblast outgrowth length (−35%, P ≤ .001 and −26%, P < .05) and area (−43%, P ≤ .001 and −36%, P ≤ .01) without altering trophoblast proliferation or apoptosis. Short‐term treatment of primary first trimester trophoblasts with IL‐6 (10 ng/mL), interleukin 10 (IL‐10) (50 ng/mL), and tumor necrosis factor α (TNF‐α) (10 ng/mL) did not affect MMP15 protein levels. Likewise, MMP15 mRNA and protein levels were unaltered between human first trimester placentas from control pregnancies vs those complicated with maternal obesity. Overall, our results suggest that the role of MMP15 in placental development and function in early pregnancy is limited to CTB invasion without being affected by short‐ and long‐term inflammation.

Sex matters: XIST and DDX3Y gene expression as a tool to determine fetal sex in human first trimester placenta

Fetal sex influences placental function as well as maternal and fetal health, being an important factor to consider in pregnancy studies. However, fetal sex determination in the first trimester of pregnancy still faces some technical limitations. Here we describe an RT-qPCR technique to determine fetal sex based on X-inactive specific transcript (XIST) and DEAD-Box helicase 3 Y-linked (DDX3Y) gene expression. This method is straightforward, reliable, fast and applicable on both, placental tissue and primary cells.

Gestational Age-Dependent Abundance of Human Placental Transporters as Determined by Quantitative Targeted Proteomics.

Some women take medication during pregnancy to address a variety of clinical conditions. Because of ethical and logistical concerns, it is impossible to determine fetal drug exposure, and therefore fetal risk, during pregnancy. Hence, alternative approaches need to be developed to predict maternal-fetal drug exposure throughout pregnancy. To do so, we previously developed and verified a maternal-fetal physiologically based pharmacokinetic model, which can predict fetal exposure to drugs that passively cross the placenta. However, many drugs are actively transported by the placenta (e.g., human immunodeficiency virus protease inhibitors). To extend our maternal-fetal physiologically based pharmacokinetic model to these actively transported drugs, we determined the gestational age–dependent changes in the protein abundance of placental transporters. Total cellular membrane fractions from first trimester (T1; n = 15), second trimester (T2; n = 19), and term (n = 15) human placentae obtained from uncomplicated pregnancies were isolated by ultracentrifugation. Transporter protein abundance was determined by targeted quantitative proteomics using liquid chromatography tandem mass specrometry. We observed that breast cancer resistance protein and P-glycoprotein abundance significantly decreased from T1 to term by 55% and 69%, respectively (per gram of tissue). Organic anion–transporting polypeptide (OATP) 2B1 abundance significantly decreased from T1 to T2 by 32%. In contrast, organic cation transporter (OCT) 3 and organic anion transporter 4 abundance significantly increased with gestational age (2-fold from T1 to term, 1.6-fold from T2 to term). Serotonin transporter and norepinephrine transporter did not change with gestational age. The abundance of bile salt export pump, multidrug resistance-associated protein 1-5, Na+-taurocholate cotransporting polypeptide, OATP1B1, OATP1B3, OCTN1-2, concentrative nucleoside transporter 1-3, equilibrative nucleoside transporter 2, and multidrug and toxin extrusion 1 could not be quantified. These data can be incorporated into our maternal-fetal physiologically based pharmacokinetic model to predict fetal exposure to drugs that are actively transported across the placenta.SIGNIFICANCE STATEMENTWe quantified the protein abundance of key placental uptake and efflux transporters [organic cation transporter (OCT) 3, P-glycoprotein (P-gp), breast cancer resistance protein (BCRP)] across gestational ages (first trimester, second trimester, and term) using quantitative targeted proteomics. We observed that the protein abundance of P-gp and BCRP decreased, whereas that of OCT3 increased with gestational age. Incorporating the protein abundance determined in this study into maternal-fetal physiologically based pharmacokinetic model can help us better predict fetal drug exposure to substrates of these transporters.