Directed biomechanical compressive forces enhance fusion efficiency in model placental trophoblast cultures.

The syncytiotrophoblast is a multinucleated structure that arises from fusion of mononucleated cytotrophoblasts, to sheath the placental villi and regulate transport across the maternal-fetal interface. Here, we ask whether the dynamic mechanical forces that must arise during villous development might influence fusion, and explore this question using in vitro choriocarcinoma trophoblast models. We demonstrate that mechanical stress patterns arise around sites of localized fusion in cell monolayers, in patterns that match computational predictions of villous morphogenesis. We then externally apply these mechanical stress patterns to cell monolayers and demonstrate that equibiaxial compressive stresses (but not uniaxial or equibiaxial tensile stresses) enhance expression of the syndecan-1 and loss of E-cadherin as markers of fusion. These findings suggest that the mechanical stresses that contribute towards sculpting the placental villi may also impact fusion in the developing tissue. We then extend this concept towards 3D cultures and demonstrate that fusion can be enhanced by applying low isometric compressive stresses to spheroid models, even in the absence of an inducing agent. These results indicate that mechanical stimulation is a potent activator of cellular fusion, suggesting novel avenues to improve experimental reproductive modelling, placental tissue engineering, and understanding disorders of pregnancy development.

PRDM14 extinction enables the initiation of trophoblast stem cell formation.

Trophoblast stem cells (TSCs) can be chemically converted from embryonic stem cells (ESCs) in vitro. Although several transcription factors (TFs) have been recognized as essential for TSC formation, it remains unclear how differentiation cues link elimination of stemness with the establishment of TSC identity. Here, we show that PRDM14, a critical pluripotent circuitry component, is reduced during the formation of TSCs. The reduction is further shown to be due to the activation of Wnt/ß-catenin signaling. The extinction of PRDM14 results in the erasure of H3K27me3 marks and chromatin opening in the gene loci of TSC TFs, including GATA3 and TFAP2C, which enables their expression and thus the initiation of the TSC formation process. Accordingly, PRDM14 reduction is proposed here as a critical event that couples elimination of stemness with the initiation of TSC formation. The present study provides novel insights into how induction signals initiate TSC formation.

Unlocking trophectoderm mysteries: In vivo and in vitro perspectives on human and mouse trophoblast fate induction.

In recent years, the pursuit of inducing the trophoblast stem cell (TSC) state has gained prominence as a compelling research objective, illuminating the establishment of the trophoblast lineage and unlocking insights into early embryogenesis. In this review, we examine how advancements in diverse technologies, including in vivo time course transcriptomics, cellular reprogramming to TSC state, chemical induction of totipotent stem-cell-like state, and stem-cell-based embryo-like structures, have enriched our insights into the intricate molecular mechanisms and signaling pathways that define the mouse and human trophectoderm/TSC states. We delve into disparities between mouse and human trophectoderm/TSC fate establishment, with a special emphasis on the intriguing role of pluripotency in this context. Additionally, we re-evaluate recent findings concerning the potential of totipotent-stem-like cells and embryo-like structures to fully manifest the trophectoderm/trophoblast lineage's capabilities. Lastly, we briefly discuss the potential applications of induced TSCs in pregnancy-related disease modeling.

Human trophoblast stem cells restrict human cytomegalovirus replication.

Placental infection plays a central role in the pathogenesis of congenital human cytomegalovirus (HCMV) infections and is a cause of fetal growth restriction and pregnancy loss. HCMV can replicate in some trophoblast cell types, but it remains unclear how the virus evades antiviral immunity in the placenta and how infection compromises placental development and function. Human trophoblast stem cells (TSCs) can be differentiated into extravillous trophoblasts (EVTs), syncytiotrophoblasts (STBs), and organoids, and this study assessed the utility of TSCs as a model of HCMV infection in the first-trimester placenta. HCMV was found to non-productively infect TSCs, EVTs, and STBs. Immunofluorescence assays and flow cytometry experiments further revealed that infected TSCs frequently only express immediate early viral gene products. Similarly, RNA sequencing found that viral gene expression in TSCs does not follow the kinetic patterns observed during lytic infection in fibroblasts. Canonical antiviral responses were largely not observed in HCMV-infected TSCs and TSC-derived trophoblasts. Rather, infection dysregulated factors involved in cell identity, differentiation, and Wingless/Integrated signaling. Thus, while HCMV does not replicate in TSCs, infection may perturb trophoblast differentiation in ways that could interfere with placental function. IMPORTANCE: Placental infection plays a central role in human cytomegalovirus (HCMV) pathogenesis during pregnancy, but the species specificity of HCMV and the limited availability and lifespan of primary trophoblasts have been persistent barriers to understanding how infection impacts this vital organ. Human trophoblast stem cells (TSCs) represent a new approach to modeling viral infection early in placental development. This study reveals that TSCs, like other stem cell types, restrict HCMV replication. However, infection perturbs the expression of genes involved in differentiation and cell fate determination, pointing to a mechanism by which HCMV could cause placental injury.

C-C motif chemokine ligand 2 regulates prostaglandin synthesis and embryo attachment of the bovine endometrium during implantation.

C-C motif chemokine ligand 2 (CCL2) has been reported to be expressed in the bovine endometrium during pregnancy. However, the details of its functions involved in the implantation mechanism are still not clear. The purpose of this study is to analyze the functional properties of CCL2 in the bovine endometrium and embryos. The expression of CCR2 was not different between the luteal phase and implantation phase of their endometrial tissues, but was significantly high in IFNa treated bovine endometrial stromal (BES) cells in vitro. The expressions of PGES1, PGES2, AKR1C4, and AKR1C4 were high at the implantation stage compared with the luteal stage. On the other hand, PGES2 and AKR1B1 in BEE and PGES3 and AKR1A1 in BES were significantly increased by CCL2 treatment, respectively. The expressions of PCNA and IFNt were found significantly high in the bovine trophoblastic cells (BT) treated with CCL2 compared to the control. CCL2 significantly increased the attachment rate of BT vesicles to BEE in in vitro co-culture system. The expression of OPN and ICAM-1 increased in BEE, and ICAM-1 increased in BT by CCL2 treatment, respectively. The present results indicate that CCL2 has the potential to regulate the synthesis of PGs in the endometrium and the embryo growth. In addition, CCL2 has the possibility to regulate the process of bovine embryo attachment to the endometrium by modulation of binding molecules expression.

Establishment and comparison of human term placenta-derived trophoblast cells†.

Research on the biology of fetal-maternal barriers has been limited by access to physiologically relevant cells, including trophoblast cells. In this study, we describe the development of a human term placenta-derived cytotrophoblast immortalized cell line (hPTCCTB) derived from the basal plate. Human-term placenta-derived cytotrophoblast immortalized cell line cells are comparable to their primary cells of origin in terms of morphology, marker expression, and functional responses. We demonstrate that these can transform into syncytiotrophoblast and extravillous trophoblasts. We also compared the hPTCCTB cells to immortalized chorionic trophoblasts (hFM-CTC), trophoblasts of the chorionic plate, and BeWo cells, choriocarcinoma cell lines of conventional use. Human-term placenta-derived cytotrophoblast immortalized cell line and hFM-CTCs displayed more similarity to each other than to BeWos, but these differ in syncytialization ability. Overall, this study (1) demonstrates that the immortalized hPTCCTB generated are cells of higher physiological relevance and (2) provides a look into the distinction between the spatially distinct placental and fetal barrier trophoblasts cells, hPTCCTB and hFM-CTC, respectively.

Complete human day 14 post-implantation embryo models from naive ES cells.

The ability to study human post-implantation development remains limited owing to ethical and technical challenges associated with intrauterine development after implantation1. Embryo-like models with spatially organized morphogenesis and structure of all defining embryonic and extra-embryonic tissues of the post-implantation human conceptus (that is, the embryonic disc, the bilaminar disc, the yolk sac, the chorionic sac and the surrounding trophoblast layer) remain lacking1,2. Mouse naive embryonic stem cells have recently been shown to give rise to embryonic and extra-embryonic stem cells capable of self-assembling into post-gastrulation structured stem-cell-based embryo models with spatially organized morphogenesis (called SEMs)3. Here we extend those findings to humans using only genetically unmodified human naive embryonic stem cells (cultured in human enhanced naive stem cell medium conditions)4. Such human fully integrated and complete SEMs recapitulate the organization of nearly all known lineages and compartments of post-implantation human embryos, including the epiblast, the hypoblast, the extra-embryonic mesoderm and the trophoblast layer surrounding the latter compartments. These human complete SEMs demonstrated developmental growth dynamics that resemble key hallmarks of post-implantation stage embryogenesis up to 13-14 days after fertilization (Carnegie stage 6a). These include embryonic disc and bilaminar disc formation, epiblast lumenogenesis, polarized amniogenesis, anterior-posterior symmetry breaking, primordial germ-cell specification, polarized yolk sac with visceral and parietal endoderm formation, extra-embryonic mesoderm expansion that defines a chorionic cavity and a connecting stalk, and a trophoblast-surrounding compartment demonstrating syncytium and lacunae formation. This SEM platform will probably enable the experimental investigation of previously inaccessible windows of human early post implantation up to peri-gastrulation development.

Spheroid formation induces chemokine production in trophoblast-derived Swan71 cells.

PROBLEM: In the cell column of anchoring villi, the cytotrophoblast differentiates into extravillous trophoblast (EVT) and invades the endometrium in contact with maternal immune cells. Recently, chemokines were proposed to regulate the decidual immune response. To investigate the roles of chemokines around the anchoring villi, we examined the expression profiles of chemokines in the first-trimester trophoblast-derived Swan71 cells using a three-dimensional culture model. METHOD OF STUDY: The gene expressions in the spheroid-formed Swan71 cells were examined by microarray and qPCR analyses. The protein expressions were examined by immunochemical staining. The chemoattractant effects of spheroid-formed Swan71 cells were examined by migration assay using monocyte-derived THP-1 cells. RESULTS: The expressions of an EVT marker, laeverin, and matrix metalloproteases, MMP2 and MMP9, were increased in the spheroid-cultured Swan71 cells. Microarray and qPCR analysis revealed that mRNA expressions of various chemokines, CCL2, CCL7, CCL20, CXCL1, CXCL2, CXCL5, CXCL6, CXCL8, and CXCL10, in the spheroid-cultured Swan71 cells were up-regulated as compared with those in the monolayer-cultured Swan71 cells. These expressions were significantly suppressed by hypoxia. Migration assay showed that culture media derived from the spheroid-formed Swan71 cells promoted THP-1 cell migration. CONCLUSION: This study indicated that chemokine expressions in Swan71 cells increase under a spheroid-forming culture and the culture media have chemoattractant effects. Since three-dimensional cell assembling in the spheroid resembles the structure of the cell column, this study also suggests that chemokines play important roles in the interaction between EVT and immune cells in their early differentiation stage.

Core conserved transcriptional regulatory networks define the invasive trophoblast cell lineage.

The invasive trophoblast cell lineages in rat and human share crucial responsibilities in establishing the uterine-placental interface of the hemochorial placenta. These observations have led to the rat becoming an especially useful animal model for studying hemochorial placentation. However, our understanding of similarities or differences between regulatory mechanisms governing rat and human invasive trophoblast cell populations is limited. In this study, we generated single-nucleus ATAC-seq data from gestation day 15.5 and 19.5 rat uterine-placental interface tissues, and integrated the data with single-cell RNA-seq data generated at the same stages. We determined the chromatin accessibility profiles of invasive trophoblast, natural killer, macrophage, endothelial and smooth muscle cells, and compared invasive trophoblast chromatin accessibility with extravillous trophoblast cell accessibility. In comparing chromatin accessibility profiles between species, we found similarities in patterns of gene regulation and groups of motifs enriched in accessible regions. Finally, we identified a conserved gene regulatory network in invasive trophoblast cells. Our data, findings and analysis will facilitate future studies investigating regulatory mechanisms essential for the invasive trophoblast cell lineage.

A spatially resolved timeline of the human maternal-fetal interface.

Beginning in the first trimester, fetally derived extravillous trophoblasts (EVTs) invade the uterus and remodel its spiral arteries, transforming them into large, dilated blood vessels. Several mechanisms have been proposed to explain how EVTs coordinate with the maternal decidua to promote a tissue microenvironment conducive to spiral artery remodelling (SAR)1-3. However, it remains a matter of debate regarding which immune and stromal cells participate in these interactions and how this evolves with respect to gestational age. Here we used a multiomics approach, combining the strengths of spatial proteomics and transcriptomics, to construct a spatiotemporal atlas of the human maternal-fetal interface in the first half of pregnancy. We used multiplexed ion beam imaging by time-of-flight and a 37-plex antibody panel to analyse around 500,000 cells and 588 arteries within intact decidua from 66 individuals between 6 and 20 weeks of gestation, integrating this dataset with co-registered transcriptomics profiles. Gestational age substantially influenced the frequency of maternal immune and stromal cells, with tolerogenic subsets expressing CD206, CD163, TIM-3, galectin-9 and IDO-1 becoming increasingly enriched and colocalized at later time points. By contrast, SAR progression preferentially correlated with EVT invasion and was transcriptionally defined by 78 gene ontology pathways exhibiting distinct monotonic and biphasic trends. Last, we developed an integrated model of SAR whereby invasion is accompanied by the upregulation of pro-angiogenic, immunoregulatory EVT programmes that promote interactions with the vascular endothelium while avoiding the activation of maternal immune cells.

Spatial multiomics map of trophoblast development in early pregnancy.

The relationship between the human placenta-the extraembryonic organ made by the fetus, and the decidua-the mucosal layer of the uterus, is essential to nurture and protect the fetus during pregnancy. Extravillous trophoblast cells (EVTs) derived from placental villi infiltrate the decidua, transforming the maternal arteries into high-conductance vessels1. Defects in trophoblast invasion and arterial transformation established during early pregnancy underlie common pregnancy disorders such as pre-eclampsia2. Here we have generated a spatially resolved multiomics single-cell atlas of the entire human maternal-fetal interface including the myometrium, which enables us to resolve the full trajectory of trophoblast differentiation. We have used this cellular map to infer the possible transcription factors mediating EVT invasion and show that they are preserved in in vitro models of EVT differentiation from primary trophoblast organoids3,4 and trophoblast stem cells5. We define the transcriptomes of the final cell states of trophoblast invasion: placental bed giant cells (fused multinucleated EVTs) and endovascular EVTs (which form plugs inside the maternal arteries). We predict the cell-cell communication events contributing to trophoblast invasion and placental bed giant cell formation, and model the dual role of interstitial EVTs and endovascular EVTs in mediating arterial transformation during early pregnancy. Together, our data provide a comprehensive analysis of postimplantation trophoblast differentiation that can be used to inform the design of experimental models of the human placenta in early pregnancy.

Laminin switches terminal differentiation fate of human trophoblast stem cells under chemically defined culture conditions.

Human trophoblast stem cells (hTSCs) have emerged as a powerful tool to model early placental development in vitro. Analogous to the epithelial cytotrophoblast in the placenta, hTSCs can differentiate into cells of the extravillous trophoblast (EVT) lineage or the multinucleate syncytiotrophoblast (STB). Here we present a chemically defined culture system for STB and EVT differentiation of hTSCs. Notably, in contrast to current approaches, we neither utilize forskolin for STB formation nor transforming growth factor-beta (TGFß) inhibitors or a passage step for EVT differentiation. Strikingly, the presence of a single additional extracellular cue-laminin-111-switched the terminal differentiation of hTSCs from STB to the EVT lineage under these conditions. In the absence of laminin-111, STB formation occurred, with cell fusion comparable to that obtained with differentiation mediated by forskolin; however, in the presence of laminin-111, hTSCs differentiated to the EVT lineage. Protein expression of nuclear hypoxia-inducible factors (HIF1α and HIF2α) was upregulated during EVT differentiation mediated by laminin-111 exposure. A heterogeneous mixture of Notch1+ EVTs in colonies and HLA-G+ single-cell EVTs were obtained without a passage step, reminiscent of heterogeneity in vivo. Further analysis showed that inhibition of TGFß signaling affected both STB and EVT differentiation mediated by laminin-111 exposure. TGFß inhibition during EVT differentiation resulted in decreased HLA-G expression and increased Notch1 expression. On the other hand, TGFß inhibition prevented STB formation. The chemically defined culture system for hTSC differentiation established herein facilitates quantitative analysis of heterogeneity that arises during hTSC differentiation and will enable mechanistic studies in vitro.

Hsa_circ_0001326 inhibited the proliferation, migration, and invasion of trophoblast cells via miR-145-5p/TGFB2 axis.

PROBLEM: Preeclampsia (PE) is an obstetric disease involving multiple systems, which account for maternal and fetal complications and increased mortality. Circular RNAs (circRNAs) were recently deemed to associate with the pathogenesis of PE. This study aims to clarify the correlation between circRNA hsa_circ_0001326 and PE and explore its biological function in PE. METHOD OF STUDY: The expression of hsa_circ_0001326 in PE placentas was detected by real-time quantitative PCR (qRT-PCR). After overexpressing or inhibiting hsa_circ_0001326 in trophoblast cells, the cell growth, migration, and invasion were evaluated by Cell Counting Kit-8 (CCK-8) and transwell assays. Western blot assay was applied to detect the epithelial-mesenchymal transition (EMT) proteins, E-cadherin and Vimentin. Furthermore, a dual-luciferase reporter assay was applied to verify the binding sites of hsa_circ_0001326, miR-145-5p, and transforming growth factor beta 2 (TGFB2). RESULTS: Hsa_circ_0001326 was found to be higher expressed in PE placentas than in normal placentas. Furthermore, hsa_circ_0001326 played a negative regulating role in trophoblast cell viability, migration, and invasion. Overexpression of hsa_circ_0001326 inhibited the viability, migration, and invasion of trophoblast cells, while inhibition of hsa_circ_0001326 showed opposite effects. Mechanistically, hsa_circ_0001326 sponged miR-145-5p to elevate TGFB2 expression in trophoblast cells. CONCLUSION: This study provided evidence that the up-regulated hsa_circ_0001326 in PE restrained trophoblast cells proliferation, migration, and invasion by sponging miR-145-5p to elevate TGFB2 expression. Our results might provide a novel insight into the role of hsa_circ_0001326 in the pathogenesis of PE.

Extracellular vesicles secreted by human uterine stromal cells regulate decidualization, angiogenesis, and trophoblast differentiation.

In humans, the uterus undergoes a dramatic transformation to form an endometrial stroma-derived secretory tissue, termed decidua, during early pregnancy. The decidua secretes various factors that act in an autocrine/paracrine manner to promote stromal differentiation, facilitate maternal angiogenesis, and influence trophoblast differentiation and development, which are critical for the formation of a functional placenta. Here, we investigated the mechanisms by which decidual cells communicate with each other and with other cell types within the uterine milieu. We discovered that primary human endometrial stromal cells (HESCs) secrete extracellular vesicles (EVs) during decidualization and that this process is controlled by a conserved HIF2α-RAB27B pathway. Mass spectrometry revealed that the decidual EVs harbor a variety of protein cargo, including cell signaling molecules, growth modulators, metabolic regulators, and factors controlling endothelial cell expansion and remodeling. We tested the hypothesis that EVs secreted by the decidual cells mediate functional communications between various cell types within the uterus. We demonstrated that the internalization of EVs, specifically those carrying the glucose transporter 1 (GLUT1), promotes glucose uptake in recipient HESCs, supporting and advancing the decidualization program. Additionally, delivery of HESC-derived EVs into human endothelial cells stimulated their proliferation and led to enhanced vascular network formation. Strikingly, stromal EVs also promoted the differentiation of trophoblast stem cells into the extravillous trophoblast lineage. Collectively, these findings provide a deeper understanding of the pleiotropic roles played by EVs secreted by the decidual cells to ensure coordination of endometrial differentiation and angiogenesis with trophoblast function during the progressive phases of decidualization and placentation.

Hippo signaling cofactor, WWTR1, at the crossroads of human trophoblast progenitor self-renewal and differentiation.

Healthy progression of human pregnancy relies on cytotrophoblast (CTB) progenitor self-renewal and its differentiation toward multinucleated syncytiotrophoblasts (STBs) and invasive extravillous trophoblasts (EVTs). However, the underlying molecular mechanisms that fine-tune CTB self-renewal or direct its differentiation toward STBs or EVTs during human placentation are poorly defined. Here, we show that Hippo signaling cofactor WW domain containing transcription regulator 1 (WWTR1) is a master regulator of trophoblast fate choice during human placentation. Using human trophoblast stem cells (human TSCs), primary CTBs, and human placental explants, we demonstrate that WWTR1 promotes self-renewal in human CTBs and is essential for their differentiation to EVTs. In contrast, WWTR1 prevents induction of the STB fate in undifferentiated CTBs. Our single-cell RNA sequencing analyses in first-trimester human placenta, along with mechanistic analyses in human TSCs revealed that WWTR1 fine-tunes trophoblast fate by directly regulating WNT signaling components. Importantly, our analyses of placentae from pathological pregnancies show that extreme preterm births (gestational time ≤28 wk) are often associated with loss of WWTR1 expression in CTBs. In summary, our findings establish the critical importance of WWTR1 at the crossroads of human trophoblast progenitor self-renewal versus differentiation. It plays positive instructive roles in promoting CTB self-renewal and EVT differentiation and safeguards undifferentiated CTBs from attaining the STB fate.

MiR-30a-3p Targeting FLT1 Modulates Trophoblast Cell Proliferation in the Pathogenesis of Preeclampsia.

Preeclampsia (PE) may pose significant adverse effects on pregnant women. Dysregulation of angiogenesis, trophoblast invasion, and proliferation are known to be associated with PE development and progression. Fms related tyrosine kinase 1 (FLT1), an anti-angiogenic factor, is consistently upregulated in PE patients. Recent papers highlight that aberrant miR-30a-3p expression contributes to PE development. More effects are needed to assess the biological function of placental miR-30a-3p in PE. The soluble FLT1 (sFLT1) and FLT1 levels were tested by ELISA assay and Western blotting assay. mRNA levels were measured by RT-qPCR assay. Colony formation and MTT assays were applied to assess the effect of miR-30a-3p on trophoblast cell proliferation. The serum sFLT1 and placental FLT1 levels were substantially high in patients with PE. Using miRNA microarray assay, we identified miR-30a-3p upregulation in PE patients' placenta tissues. We further confirmed that miR-30a-3p binds to the 3'-UTR of FLT1 gene and positively regulate its expression. Forcing miR-30a-3p expression inhibited trophoblast cell proliferation and vice versa. In conclusion, persistent high levels of FLT1 and miR-30a-3p may pose adverse effects on angiogenesis and trophoblast proliferation in placenta of PE patients. Therefore, targeting FLT1 and miR-30a-3p may serve as ideal strategies for managing patients with PE.

Transforming growth factor-ß signaling governs the differentiation program of extravillous trophoblasts in the developing human placenta.

Abnormal placentation has been noticed in a variety of pregnancy complications such as miscarriage, early-onset preeclampsia, and fetal growth restriction. Defects in the developmental program of extravillous trophoblasts (EVTs), migrating from placental anchoring villi into the maternal decidua and its vessels, is thought to be an underlying cause. Yet, key regulatory mechanisms controlling commitment and differentiation of the invasive trophoblast lineage remain largely elusive. Herein, comparative gene expression analyses of HLA-G-purified EVTs, isolated from donor-matched placenta, decidua, and trophoblast organoids (TB-ORGs), revealed biological processes and signaling pathways governing EVT development. In particular, bioinformatics analyses and manipulations in different versatile trophoblast cell models unraveled transforming growth factor-ß (TGF-ß) signaling as a crucial pathway driving differentiation of placental EVTs into decidual EVTs, the latter showing enrichment of a secretory gene signature. Removal of Wingless signaling and subsequent activation of the TGF-ß pathway were required for the formation of human leukocyte antigen-G+ (HLA-G+) EVTs in TB-ORGs that resemble in situ EVTs at the level of global gene expression. Accordingly, TGF-ß-treated EVTs secreted enzymes, such as DAO and PAPPA2, which were predominantly expressed by decidual EVTs. Their genes were controlled by EVT-specific induction and genomic binding of the TGF-ß downstream effector SMAD3. In summary, TGF-ß signaling plays a key role in human placental development governing the differentiation program of EVTs.

Downregulation of CDC42 inhibits the proliferation and stemness of human trophoblast stem cell via EZRIN/YAP inactivation.

Placental dysplasia increases the risk of recurrent spontaneous abortion (RSA). However, the underlying mechanism regulating placental development remains unclear. In this study, we showed that the expression of CDC42 was decreased in the villous tissue of RSA samples compared to healthy controls. Further examination demonstrated that CDC42 deficiency led to the differentiation of human trophoblast stem cells (hTSCs) and inhibited their proliferation. Genetic manipulation of YAP and EZRIN in hTSCs revealed that CDC42 regulates the stemness and proliferation of hTSCs; this is dependent on EZRIN, which translocates YAP into the nucleus. Moreover, the expression pattern of EZRIN, YAP, and Ki67 was also abnormal in the villous tissue of RSA samples, consistent with in vitro experiments. In summary, these findings suggest that the CDC42/EZRIN/YAP pathway plays an important role in placental development.

MiR-135a-5p suppresses trophoblast proliferative, migratory, invasive, and angiogenic activity in the context of unexplained spontaneous abortion.

BACKGROUND: Spontaneous abortions (SA) is amongst the most common complications associated with pregnancy in humans, and the underlying causes cannot be identified in roughly half of SA cases. We found miR-135a-5p to be significantly upregulated in SA-associated villus tissues, yet the function it plays in this context has yet to be clarified. This study explored the function of miR-135a-5p and its potential as a biomarker for unexplained SA. METHOD: RT-qPCR was employed for appraising miR-135a-5p expression within villus tissues with its clinical diagnostic values being assessed using ROC curves. The effects of miR-135a-5p in HTR-8/SVneo cells were analyzed via wound healing, Transwell, flow cytometry, EdU, CCK-8, and tube formation assays. Moreover, protein expression was examined via Western blotting, and interactions between miR-135a-5p and PTPN1 were explored through RIP-PCR, bioinformatics analyses and luciferase reporter assays. RESULTS: Relative to normal pregnancy (NP), villus tissue samples from pregnancies that ended in unexplained sporadic miscarriage (USM) or unexplained recurrent SA (URSA) exhibited miR-135a-5p upregulation. When this miRNA was overexpressed in HTR-8/SVneo cells, their migration, proliferation, and cell cycle progression were suppressed, as were their tube forming and invasive activities. miR-135a-5p over-expression also downregulated the protein level of cyclins, PTPN1, MMP2 and MMP9. In RIP-PCR assays, the Ago2 protein exhibited significant miR-135a-5p and PTPN1 mRNA enrichment, and dual-luciferase reporter assays indicated PTPN1 to be a bona fide miR-135a-5p target gene within HTR-8/SVneo cells. CONCLUSION: miR-135a-5p may suppress trophoblast migratory, invasive, proliferative, and angiogenic activity via targeting PTPN1, and it may thus offer value as a biomarker for unexplained SA.

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.