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Cite this page: Hill, M.A. (2024, May 26) Embryology Trophoblast. Retrieved from

Trophoblast - Protein Expression


Saha B, Ganguly A, Home P, Bhattacharya B, Ray S, Ghosh A, Rumi MAK, Marsh C, French VA, Gunewardena S & Paul S. (2020). TEAD4 ensures postimplantation development by promoting trophoblast self-renewal: An implication in early human pregnancy loss. Proc. Natl. Acad. Sci. U.S.A. , , . PMID: 32669432 DOI.

TEAD4 ensures postimplantation development by promoting trophoblast self-renewal: An implication in early human pregnancy loss

Early pregnancy loss affects ∼15% of all implantation-confirmed human conceptions. However, evolutionarily conserved molecular mechanisms that regulate self-renewal of trophoblast progenitors and their association with early pregnancy loss are poorly understood. Here, we provide evidence that transcription factor TEAD4 ensures survival of postimplantation mouse and human embryos by controlling self-renewal and stemness of trophoblast progenitors within the placenta primordium. In an early postimplantation mouse embryo, TEAD4 is selectively expressed in trophoblast stem cell-like progenitor cells (TSPCs), and loss of Tead4 in postimplantation mouse TSPCs impairs their self-renewal, leading to embryonic lethality before embryonic day 9.0, a developmental stage equivalent to the first trimester of human gestation. Both TEAD4 and its cofactor, yes-associated protein 1 (YAP1), are specifically expressed in cytotrophoblast (CTB) progenitors of a first-trimester human placenta. We also show that a subset of unexplained recurrent pregnancy losses (idiopathic RPLs) is associated with impaired TEAD4 expression in CTB progenitors. Furthermore, by establishing idiopathic RPL patient-specific human trophoblast stem cells (RPL-TSCs), we show that loss of TEAD4 is associated with defective self-renewal in RPL-TSCs and rescue of TEAD4 expression restores their self-renewal ability. Unbiased genomics studies revealed that TEAD4 directly regulates expression of key cell cycle genes in both mouse and human TSCs and establishes a conserved transcriptional program. Our findings show that TEAD4, an effector of the Hippo signaling pathway, is essential for the establishment of pregnancy in a postimplantation mammalian embryo and indicate that impairment of the Hippo signaling pathway could be a molecular cause for early human pregnancy loss.


West RC, Ming H, Logsdon DM, Sun J, Rajput SK, Kile RA, Schoolcraft WB, Roberts RM, Krisher RL, Jiang Z & Yuan Y. (2019). Dynamics of trophoblast differentiation in peri-implantation-stage human embryos. Proc. Natl. Acad. Sci. U.S.A. , 116, 22635-22644. PMID: 31636193 DOI.

Abstract Single-cell RNA sequencing of cells from cultured human blastocysts has enabled us to define the transcriptomic landscape of placental trophoblast (TB) that surrounds the epiblast and associated embryonic tissues during the enigmatic day 8 (D8) to D12 peri-implantation period before the villous placenta forms. We analyzed the transcriptomes of 3 early placental cell types, cytoTB (CTB), syncytioTB (STB), and migratoryTB (MTB), picked manually from cultured embryos dissociated with trypsin and were able to follow sublineages that emerged from proliferating CTB at the periphery of the conceptus. A unique form of CTB with some features of STB was detectable at D8, while mature STB was at its zenith at D10. A form of MTB with a mixed MTB/CTB phenotype arose around D10. By D12, STB generation was in decline, CTB had entered a new phase of proliferation, and mature MTB cells had begun to move from the main body of the conceptus. Notably, the MTB transcriptome at D12 indicated enrichment of transcripts associated with IFN signaling, migration, and invasion and up-regulation of HLA-C, HLA-E, and HLA-G. The STB, which is distinct from the STB of later villous STB, had a phenotype consistent with intense protein export and placental hormone production, as well as migration and invasion. The studies show that TB associated with human embryos is in rapid developmental flux during peri-implantation period when it must invade, signal robustly to the mother to ensure that the pregnancy continues, and make first contact with the maternal immune system. KEYWORDS: human endogenous retroviruses; interferon; single-cell RNA sequencing; transcriptome PMID: 31636193 PMCID: PMC6842583 [Available on 2020-04-21] DOI: 10.1073/pnas.1911362116

Song X, Li C, Li J, Liu L, Meng L, Ding H & Long W. (2019). The long noncoding RNA uc.294 is upregulated in early-onset pre-eclampsia and inhibits proliferation, invasion of trophoblast cells (HTR-8/SVneo). J. Cell. Physiol. , 234, 11001-11008. PMID: 30569493 DOI. Abstract Recently, a large number of long noncoding RNAs (lncRNAs) have been reported in human diseases that are evolutionarily conserved and are likely to play a role in many biological events including pre-eclampsia. In our previous research, we selected thousands of lncRNAs for their relationship with early-onset pre-eclampsia. Among these lncRNAs, a lncRNA named uc.294 attracted our attention, was once reported to specifically be expressed at a high level in the early-onset of pre-eclampsia. This study aims to investigate the function of uc.294 in early-onset pre-eclampsia and the possible mechanism. The uc.294 expression level in early-onset pre-eclampsia or in normal placenta tissues was evaluated by quantitative real-time polymerase chain reaction. To detect the proliferation, invasion, and apoptosis capacity of the trophoblast cells, we performed the Cell Counting Kit-8 assay, transwell assay, and flow cytometry, respectively. Here we report, for the first time, that uc.294 inhibits proliferation, invasion, and promotes apoptosis of trophoblast cells HTR-8/SVneo by working in key aspects of biological behaviors. However, how uc.294 acts to regulate gene functions in early-onset pre-eclampsia needs further exploration.

© 2018 Wiley Periodicals, Inc.

KEYWORDS: early-onset pre-eclampsia; function; lncRNA; trophoblast cells; uc.294 PMID: 30569493 DOI: 10.1002/jcp.27916

Hu KL, Chang HM, Zhao HC, Yu Y, Li R & Qiao J. (2019). Potential roles for the kisspeptin/kisspeptin receptor system in implantation and placentation. Hum. Reprod. Update , 25, 326-343. PMID: 30649364 DOI.

Abstract BACKGROUND: Initially identified as suppressors of metastasis in various types of cancer, kisspeptins are a family of neuropeptides that are key regulators of the mammalian reproductive axis. Accumulating evidence has shown that kisspeptin is able to control both the pulsatile and surge GnRH release, playing fundamental roles in female reproduction, which include the secretion of gonadotropins, puberty onset, brain sex differentiation, ovulation and the metabolic regulation of fertility. Furthermore, recent studies have demonstrated the involvement of the kisspeptin system in the processes of implantation and placentation. This review summarizes the current knowledge of the pathophysiological role and utility of these local placental regulatory factors as potential biomarkers during the early human gestation.

OBJECTIVE AND RATIONALE: A successful pregnancy, from the initiation of embryo implantation to parturition, is a complex process that requires the orchestration of a series of events. This review aims to concisely summarize what is known about the role of the kisspeptin system in implantation, placentation, early human pregnancy and pregnancy-related disorders, and to develop strategies for predicting, diagnosing and treating these abnormalities.

SEARCH METHODS: Using the PubMed and Google Scholar databases, we performed comprehensive literature searches in the English language describing the advancement of kisspeptins and the kisspeptin receptor (KISS1R) in implantation, placentation and early pregnancy in humans, since its initial identification in 1996 and ending in July 2018.

OUTCOMES: Recent studies have shown the coordinated spatial and temporal expression patterns of kisspeptins and KISS1R during human pregnancy. The experimental data gathered recently suggest putative roles of kisspeptin signaling in the regulation of trophoblast invasion, embryo implantation, placentation and early pregnancy. Dysregulation of the kisspeptin system may negatively affect the processes of implantation as well as placentation. Clinical studies indicate that the circulating levels of kisspeptins or the expression levels of kisspeptin/KISS1R in the placental tissues may be used as potential diagnostic markers for women with miscarriage and gestational trophoblastic neoplasia.

WIDER IMPLICATIONS: Comprehensive research on the pathophysiological role of the kisspeptin/KISS1R system in implantation and placentation will provide a dynamic and powerful approach to understanding the processes of early pregnancy, with potential applications in observational and analytic screening as well as the diagnosis, prognosis and treatment of implantation failure and early pregnancy-related disorders.

© The Author(s) 2019. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology.

KEYWORDS: KISS1R; early pregnancy; gestational trophoblastic neoplasia; implantation; kisspeptin; miscarriage; placentation PMID: 30649364 DOI: 10.1093/humupd/dmy046


Human placental oxygenation in late gestation: experimental and theoretical approaches

J Physiol. 2018 Dec;596(23):5523-5534. doi: 10.1113/JP275633. Epub 2018 Feb 25.

Nye GA1,2, Ingram E1,2, Johnstone ED1,2, Jensen OE3, Schneider H4, Lewis RM5, Chernyavsky IL1,2,3, Brownbill P1,2. Author information Abstract The placenta is crucial for life. It is an ephemeral but complex organ acting as the barrier interface between maternal and fetal circulations, providing exchange of gases, nutrients, hormones, waste products and immunoglobulins. Many gaps exist in our understanding of the detailed placental structure and function, particularly in relation to oxygen handling and transfer in healthy and pathological states in utero. Measurements to understand oxygen transfer in vivo in the human are limited, with no general agreement on the most appropriate methods. An invasive method for measuring partial pressure of oxygen in the intervillous space through needle electrode insertion at the time of Caesarean sections has been reported. This allows for direct measurements in vivo whilst maintaining near normal placental conditions; however, there are practical and ethical implications in using this method for determination of placental oxygenation. Furthermore, oxygen levels are likely to be highly heterogeneous within the placenta. Emerging non-invasive techniques, such as MRI, and ex vivo research are capable of enhancing and improving current imaging methodology for placental villous structure and increase the precision of oxygen measurement within placental compartments. These techniques, in combination with mathematical modelling, have stimulated novel cross-disciplinary approaches that could advance our understanding of placental oxygenation and its metabolism in normal and pathological pregnancies, improving clinical treatment options and ultimately outcomes for the patient.

© 2018 University of Oxford. The Journal of Physiology published by John Wiley & Sons Ltd on behalf of The Physiological Society.

KEYWORDS: FGR; MRI; intervillious space; modelling; oxygen; perfusion; placenta PMID: 29377190 PMCID: PMC6265570 DOI: 10.1113/JP275633

© 2018 University of Oxford. The Journal of Physiology published by John Wiley & Sons Ltd on behalf of The Physiological Society

This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

Gene expression patterns associated with human placental trophoblast differentiation

Clin Chim Acta. 2018 Jan 9. pii: S0009-8981(18)30020-2. doi: 10.1016/j.cca.2018.01.012. [Epub ahead of print]

Jiang SW1, Zhou W2, Wang J3, Little LM4, Leaphart L4, Jay J5, Igbinigie E6, Chen H7, Li J8.


Cell fusion is a hallmark of placental trophoblast cell differentiation and the mature syncytiotrophoblasts play essential roles for fetal-maternal exchange and production of pregnancy-related hormones. Using a well-established in vitro trophoblast differentiation model, we performed a microarray analysis on mRNA expression in trophoblast and syncytiotrophoblast cell cultures. Dramatic changes in gene expression patterns were detected during trophoblast differentiation. Real-time PCR analysis confirmed the reliability of the microarray data. As many as 3524 novel and known genes have been found to be up- or down-regulated for >2-fold. A number of cell cycle regulator including CDC6, CDC20, Cyclins B2, L1 and E2, were down-regulated in the syncytiotrophoblast, providing a mechanism for the loss of mitotic activity during trophoblast differentiation. Further characterization on the identified genes may lead to better understanding of placental patho-physiology in obstetric diseases such as preeclampsia. KEYWORDS: Cell fusion; Placental trophoblast; Syncytiotrophoblast; cDNA microarray PMID: 29329728 DOI: 10.1016/j.cca.2018.01.012


Prog Mol Biol Transl Sci. 2017;145:39-88. doi: 10.1016/bs.pmbts.2016.12.003. Epub 2017 Jan 16. Transcription Factors That Regulate Trophoblast Development and Function. Baines KJ1, Renaud SJ2. Author information Abstract The placenta is a transient organ that plays a critical role in sustaining pregnancy and supporting fetal growth and nutrition. The placental epithelium is comprised of trophoblast cells. Trophoblast cells are the first cell type to differentiate during embryogenesis and ultimately diversify into a heterogeneous population of cells specializing in distinct functions essential for placentation. The emergence of the trophoblast lineage and subsequent specialization into distinct trophoblast sublineages is tightly regulated by transcription factors. This chapter will provide an overview of transcription factors that regulate trophoblast development and function. The chapter is divided into three sections. In the first section, a generalized outline of trophoblast ontogeny and a functional description of different trophoblast sublineages will be provided. In the second section, transcription factors involved in emergence of the trophoblast lineage and maintenance of trophoblast stem cells will be discussed. In the third section, transcription factors implicated in the formation and function of villous and extravillous cytotrophoblast lineages will be described.

© 2017 Elsevier Inc. All rights reserved.

KEYWORDS: Cell proliferation and differentiation; Placenta; Syncytialization; Transcription factors; Trophoblast; Trophoblast stem cells PMID: 28110754 DOI: 10.1016/bs.pmbts.2016.12.003

Invasive trophoblast promote stromal fibroblast decidualization via Profilin 1 and ALOX5

Sci Rep. 2017 Aug 18;7(1):8690. doi: 10.1038/s41598-017-05947-0.

Menkhorst EM1,2, Van Sinderen ML1,2, Rainczuk K1,2, Cuman C1,2, Winship A1,3,2, Dimitriadis E4,5,6.


During the establishment of pregnancy, extravillous trophoblast (EVT) must invade into the uterine decidua to facilitate decidual artery remodelling to create the placental blood supply. The local decidual environment is thought to regulate trophoblast invasion, however these interactions are poorly defined in humans. Recent evidence in women suggests impaired decidualization is associated with miscarriage and preeclampsia. Primary human endometrial stromal cells (HESC) and first trimester extravillous trophoblast (EVTs) were used to assess the effect of EVT-secreted factors on HESC decidualization, adhesion, proliferation and migration. We determined the role of profilin (PFN)1, an EVT-secreted factor, on HESC function and identified a downstream target of PFN1. EVT-secreted factors induced HESC decidualization and enhanced decidualized HESC adhesion, proliferation and migration. Recombinant PFN1 enhanced methoxyprogesterone acetate-induced HESC decidualization and proliferation. PFN1 down-regulated the expression of lipoxygenase arachidonate 5-lipoxygenase (ALOX5) in HESC and THP-1 macrophages. ALOX5 localised to decidual cells and CD68+macrophages in 1st trimester decidua. This study demonstrated that EVT secretions, including PFN1, enhanced HESC decidualization and motility. This study has identified a new pathway that facilitates appropriate decidualization during the establishment of pregnancy. PMID: 28821715 PMCID: PMC5562808 DOI: 10.1038/s41598-017-05947-0

A comparative study of five physiological key parameters between four different human trophoblast-derived cell lines

Sci Rep. 2017 Jul 19;7(1):5892. doi: 10.1038/s41598-017-06364-z.

Rothbauer M1, Patel N2, Gondola H3, Siwetz M4, Huppertz B4, Ertl P3.


The human placenta plays a crucial role as the interface between mother and fetus. It represents a unique tissue that undergoes morphological as well as functional changes on the cellular and tissue level throughout pregnancy. To better understand how the placenta works, a variety of techniques has been developed to re-create this complex physiological barrier in vitro. However, due to the low availability of freshly isolated primary cells, choriocarcinoma cell lines remain the usual suspects as in vitro models for placental research. Here, we present a comparative study on the functional aspects of the choriocarcinoma cell lines BeWo, JAR and Jeg-3, as well as the first trimester trophoblast cell line ACH-3P as placental in vitro barrier models for endocrine and transport studies. Functional assays including tight junction immunostaining, sodium fluorescein retardation, trans epithelial resistance, glucose transport, hormone secretion as well as size-dependent polystyrene nanoparticle transport were performed using the four cell types to evaluate key functional parameters of each cell line to act a relevant in vitro placental barrier model.

PMID: 28724925 PMCID: PMC5517571 DOI: 10.1038/s41598-017-06364-z

Human Extravillous Trophoblasts Penetrate Decidual Veins and Lymphatics before Remodeling Spiral Arteries during Early Pregnancy

PLoS One. 2017 Jan 12;12(1):e0169849. doi: 10.1371/journal.pone.0169849. eCollection 2017.

He N1, van Iperen L1, de Jong D2, Szuhai K2, Helmerhorst FM3, van der Westerlaken LA3, Chuva de Sousa Lopes SM1,4.


In humans, the defective invasion of the maternal endometrium by fetal extravillous trophoblasts (EVTs) can lead to insufficient perfusion of the placenta, resulting in pregnancy complications that can put both mother and baby at risk. To study the invasion of maternal endometrium between (W)5.5-12 weeks of gestation by EVTs, we combined fluorescence in situ hybridization, immunofluorescence and immunohistochemistry to determine the presence of (male) EVTs in the vasculature of the maternal decidua. We observed that interstitial mononuclear EVTs directly entered decidual veins and lymphatics from W5.5. This invasion of decidual veins and lymphatics occurred long before endovascular EVTs remodelled decidual spiral arteries. This unexpected early entrance of interstitial mononuclear EVTs in the maternal circulation does not seem to contribute to the materno-placental vascular connection directly, but rather to establish (and expand) the materno-fetal interface through an alternative vascular route.

PMID 28081266 DOI: 10.1371/journal.pone.0169849


Neutrophils induce proangiogenic T cells with a regulatory phenotype in pregnancy

Proc Natl Acad Sci U S A. 2016 Dec 27;113(52):E8415-E8424. doi: 10.1073/pnas.1611944114. Epub 2016 Dec 12.

Nadkarni S1, Smith J2, Sferruzzi-Perri AN3, Ledwozyw A4, Kishore M2, Haas R2, Mauro C2, Williams DJ4, Farsky SH5, Marelli-Berg FM2, Perretti M2.

Abstract Although neutrophils are known to be fundamental in controlling innate immune responses, their role in regulating adaptive immunity is just starting to be appreciated. We report that human neutrophils exposed to pregnancy hormones progesterone and estriol promote the establishment of maternal tolerance through the induction of a population of CD4+ T cells displaying a GARP+CD127loFOXP3+ phenotype following antigen activation. Neutrophil-induced T (niT) cells produce IL-10, IL-17, and VEGF and promote vessel growth in vitro. Neutrophil depletion during murine pregnancy leads to abnormal development of the fetal-maternal unit and reduced empbryo development, with placental architecture displaying poor trophoblast invasion and spiral artery development in the maternal decidua, accompanied by significantly attenuated niT cell numbers in draining lymph nodes. Using CD45 congenic cells, we show that induction of niT cells and their regulatory function occurs via transfer of apoptotic neutrophil-derived proteins, including forkhead box protein 1 (FOXO1), to T cells. Unlike in women with healthy pregnancies, neutrophils from blood and placental samples of preeclamptic women fail to induce niT cells as a direct consequence of their inability to transfer FOXO1 to T cells. Finally, neutrophil-selective FOXO1 knockdown leads to defective placentation and compromised embryo development, similar to that resulting from neutrophil depletion. These data define a nonredundant function of neutrophil-T cell interactions in the regulation of vascularization at the maternal-fetal interface. KEYWORDS: T cells; neutrophils; placenta; pregnancy; regulatory

PMID 27956610

Preimplantation factor is an anti-apoptotic effector in human trophoblasts involving p53 signaling pathway

Cell Death Dis. 2016 Dec 1;7(12):e2504. doi: 10.1038/cddis.2016.382.

Moindjie H1, Santos ED1,2, Gouesse RJ1, Swierkowski-Blanchard N3, Serazin V1,2, Barnea ER4,5, Vialard F1,3, Dieudonné MN1.


From the earliest stages of gestation, embryonic-maternal interaction has a key role in a successful pregnancy. Various factors present during gestation may significantly influence this type of juxta/paracrine interaction. PreImplantation Factor (PIF) is a recently identified factor with activity at the fetomaternal interface. PIF is secreted by viable embryos and directly controls placental development by increasing the invasive capacity of human extravillous trophoblasts (EVTs). To further specify PIF's role in the human placenta, we analyzed the genome-wide expression profile of the EVT in the presence of a synthetic PIF analog (sPIF). We found that sPIF exposure altered several pathways related to p53 signaling, survival and the immune response. Functional assays revealed that sPIF acts through the p53 pathway to reduce both early and late trophoblast apoptosis. More precisely, sPIF (i) decreases the phosphorylation of p53 at Ser-15, (ii) enhances the B-cell lymphoma-2 (BCL2) expression and (iii) reduces the BCL2-associated X protein (BAX) and BCL2 homologous antagonist killer (BAK) mRNA expression levels. Furthermore, invalidation experiments of TP53 allowed us to demonstrate that PIF's effects on placental apoptosis seemed to be essentially mediated by this gene. We have clearly shown that p53 and sPIF pathways could interact in human trophoblast and thus promotes cell survival. Furthermore, sPIF was found to regulate a gene network related to immune tolerance in the EVT, which emphasizes the beneficial effect of this peptide on the human placenta. Finally, the PIF protein levels in placentas from pregnancies affected by preeclampsia or intra-uterine growth restriction were significantly lower than in gestational age-matched control placentas. Taken as a whole, our results suggest that sPIF protects the EVT's functional status through a variety of mechanisms. Clinical application of sPIF in the treatment of disorders of early pregnancy can be envisioned.

PMID 27906186 DOI: 10.1038/cddis.2016.382

Notch1 controls development of the extravillous trophoblast lineage in the human placenta

Proc Natl Acad Sci U S A. 2016 Nov 29;113(48):E7710-E7719. Epub 2016 Nov 14.

Haider S1, Meinhardt G1, Saleh L1, Fiala C2, Pollheimer J1, Knöfler M3.


Development of the human placenta and its different epithelial trophoblasts is crucial for a successful pregnancy. Besides fusing into a multinuclear syncytium, the exchange surface between mother and fetus, progenitors develop into extravillous trophoblasts invading the maternal uterus and its spiral arteries. Migration into these vessels promotes remodelling and, as a consequence, adaption of blood flow to the fetal-placental unit. Defects in remodelling and trophoblast differentiation are associated with severe gestational diseases, such as preeclampsia. However, mechanisms controlling human trophoblast development are largely unknown. Herein, we show that Notch1 is one such critical regulator, programming primary trophoblasts into progenitors of the invasive differentiation pathway. At the 12th wk of gestation, Notch1 is exclusively detected in precursors of the extravillous trophoblast lineage, forming cell columns anchored to the uterine stroma. At the 6th wk, Notch1 is additionally expressed in clusters of villous trophoblasts underlying the syncytium, suggesting that the receptor initiates the invasive differentiation program in distal regions of the developing placental epithelium. Manipulation of Notch1 in primary trophoblast models demonstrated that the receptor promotes proliferation and survival of extravillous trophoblast progenitors. Notch1 intracellular domain induced genes associated with stemness of cell columns, myc and VE-cadherin, in Notch1- fusogenic precursors, and bound to the myc promoter and enhancer region at RBPJκ cognate sequences. In contrast, Notch1 repressed syncytialization and expression of TEAD4 and p63, two regulators controlling self-renewal of villous cytotrophoblasts. Our results revealed Notch1 as a key factor promoting development of progenitors of the extravillous trophoblast lineage in the human placenta. KEYWORDS: Notch1; cell fusion; extravillous trophoblast; human placenta; trophoblast progenitors

PMID 27849611 PMCID: PMC5137701 DOI: 10.1073/pnas.1612335113

CD9 suppresses human extravillous trophoblast invasion

Placenta. 2016 Nov;47:105-112. doi: 10.1016/j.placenta.2016.09.014. Epub 2016 Sep 23.

Matsumoto H1, Sato Y2, Horie A3, Suginami K3, Tani H3, Hattori A4, Araki Y5, Kagami K6, Konishi I7, Fujiwara H8.


During human placentation, the extravillous trophoblast (EVT) invades the maternal decidua and reconstructs maternal spiral arteries. However, the precise mechanisms that control EVT behavior have not yet been elucidated in detail. CD9 has been reported to be a cell-motility-related molecule. Since we previously observed that CD9 was expressed on human EVT, we examined the possible involvement of CD9 in the invasion process of EVT. Placental and umbilical samples were obtained from patients who underwent legal abortions, normal delivery, or hysterectomy. The expression of CD9 at the implantation site and on isolated EVT from a villous explant culture, an EVT-derived immortalized cell line, Swan71, and HUVEC was examined by immunocytochemical staining, flow cytometry, and RT-PCR. The effects of anti-CD9 functional antibody (ALB6) on EVT and Swan71 cell invasion were further examined by matrigel invasion assay along with shRNAmir gene knockdown treatment. CD9 was highly expressed on EVT at the boundary region of EVT invasion and intravascular EVT. EVT and Swan71 cell invasions were promoted by ALB6 or shRNAmir treatment. CD9 expression on Swan71 cells was reduced under hypo-oxygenic conditions, while its expression was increased by the co-culture with HUVEC. These findings suggest that CD9 could attenuate EVT invasion under the influence of an oxygen environment and maternal endothelial cells, proposing that CD9 is a potential regulator of human placental formation. Copyright © 2016 Elsevier Ltd. All rights reserved.

KEYWORDS: CD9; Extravillous trophoblast; Invasion; Oxygen concentration; Vascular remodeling

PMID 27780531 DOI: 10.1016/j.placenta.2016.09.014

Establishment of the Human Uteroplacental Circulation: A Historical Perspective

Reprod Sci. 2016 Oct 12. pii: 1933719116669056. [Epub ahead of print]

Degner K1, Magness RR2, Shah DM3.

Abstract The uterine vasculature undergoes marked changes during pregnancy in order to provide the necessary increase in blood flow to support growth and nutrition of the uterus, placenta, and developing fetus. Pregnancy-associated uterine vascular transformations are orchestrated by a complex array of endocrine and cellular mechanisms to bring about structural modifications at the maternal-fetal interface, which collectively lead to development of the uteroplacental circulation. Understanding intrinsic uterine vascular remodeling in pregnancy is essential for understanding the physiologic and pathophysiologic regulation of maternal uterine blood flow. Aberrations of uterine vascular remodeling are potentially involved in the etiology of several pregnancy disorders, for example, preeclampsia, fetal growth restriction, and preterm labor; therefore, it is essential for subspecialist clinicians and investigators interested in reproductive physiology to fully understand the establishment of uteroplacental circulation. The foundational literature in this area is extensive; thus, a succinct review is likely to be a useful resource. Herein, we present and discuss a historical perspective on uterine vascular anatomy, maternal vascular growth associated with decidualization, trophoblast invasion, intervillous circulation, aberrations in uterine vascular modeling, and the clinical implications of improper development of the uteroplacental circulation. © The Author(s) 2016.

KEYWORDS: placenta; preeclampsia; pregnancy complications PMID 27733657

Altered Biomarkers in Trophoblast Cells Obtained Noninvasively Prior to Clinical Manifestation of Perinatal Disease

Sci Rep. 2016 Sep 23;6:32382. doi: 10.1038/srep32382.

Bolnick JM1, Kohan-Ghadr HR1, Fritz R1, Bolnick AD1, Kilburn BA1, Diamond MP2, Armant DR1,3, Drewlo S1.

Abstract A contributing factor to poor placental perfusion, leading to intrauterine growth restriction and preeclampsia, is the failure of invading extravillous trophoblast (EVT) cells to remodel the maternal uterine arteries during the first and second trimesters of pregnancy. Noninvasive assessment of EVT cells in ongoing pregnancies is possible beginning three weeks after conception, using trophoblast retrieval and isolation from the cervix (TRIC). Seven proteins were semi-quantified by immunofluorescence microscopy in EVT cells obtained between gestational weeks 6 and 20 from pregnancies with normal outcomes (N = 29) and those with intrauterine growth restriction or preeclampsia (N = 12). Significant differences were measured in expression of PAPPA, FLT1, ENG, AFP, PGF, and LGALS14, but not LGALS13 or the lineage marker KRT7. These findings provide for the first time direct evidence of pathology-associated protein dysregulation in EVT cells during early placentation. The TRIC platform provides a novel approach to acquire molecular signatures of EVT cells that can be correlated with pregnancy outcome.

PMID 27660926 PMCID: PMC5034887 DOI: 10.1038/srep32382

Function and control of human invasive trophoblast subtypes: Intrinsic vs. maternal control

Cell Adh Migr. 2016 Mar 3;10(1-2):154-62. doi: 10.1080/19336918.2015.1089376. Epub 2015 Sep 29.

Velicky P1, Knöfler M1, Pollheimer J1.


The establishment of a functional placenta is pivotal for normal fetal development and the maintenance of pregnancy. In the course of early placentation, trophoblast precursors differentiate into highly invasive trophoblast subtypes. These cells, referred to as extravillous trophoblasts (EVTs), penetrate the maternal uterus reaching as far as the inner third of the myometrium. One of the most fundamental functions of EVTs is the transformation of spiral arteries to establish the uteroplacental blood circulation assuring an adequate nutrient and gas supply to the developing fetus. To achieve this, specialized EVT subpopulations interact with maternal immune cells, provoke elastolysis in the arterial wall and replace the endothelial cells lining the spiral arteries to induce intraluminal vascular remodeling. These and other trophoblast-mediated processes are tightly controlled by paracrine signals from the maternal decidua and furthermore underlie an intrinsic cell-type specific program. Various severe pregnancy complications such as preeclampsia or intrauterine growth retardation are associated with abnormal EVT function, shallow invasion, and decreased blood flow to the placenta. Hence a better understanding of human trophoblast invasion seems mandatory to improve therapeutic intervention. This approach, however, requires a profound knowledge of the human placenta, its various trophoblast subtypes and in particular a better understanding of the regulatory network that controls the invasive phenotype of EVTs. KEYWORDS: EVT; decidua; invasion; placenta; preeclampsia; trophoblast

PMID 26418186 PMCID: PMC4853032 DOI: 10.1080/19336918.2015.1089376

The trophoblast plug during early pregnancy: a deeper insight

Histochem Cell Biol. 2016 Aug 10. [Epub ahead of print]

Weiss G1, Sundl M1, Glasner A2, Huppertz B1, Moser G3.


During the first trimester of pregnancy, foetal endovascular trophoblasts invade into maternal spiral arteries, accumulate and form plugs in the lumen of the vessels. These plugs only allow blood plasma to seep through. Hence, during the first trimester of pregnancy, a first flow of fluids through the placental intervillous space is established, resulting in a physiological oxygen gradient between mother and foetus. The trophoblast plugs block spiral arteries until the beginning of the second trimester (11-14 weeks). In parallel, uterine glands are invaded and opened by endoglandular trophoblasts towards the intervillous space of the placenta, without showing the formation of plugs (Moser et al. in Hum Reprod 25:1127-1136, 2010, Hum Reprod Oxf Engl 30:2747-2757, 2015). This enables histiotrophic nutrition of the embryo prior to onset of maternal blood flow into the placenta. Failure of these endovascular and endoglandular invasion processes may lead to miscarriage or pregnancy disorders such as intrauterine growth restriction (IUGR). After dissolution of the plugs, the onset of maternal blood flow allows maternal blood cells to enter the intervillous space and oxygen concentrations rise up. In this study, we demonstrate for the first time serial cross sections through a trophoblast plug in a first trimester placental bed specimen. Invaded and plugged arteries as well as invaded uterine glands in week 11 of gestation are visualized with specific immunohistochemical double staining techniques. We show that spiral artery plugs appear throughout the placental invasion zone and illustrate erythrocytes stowed due to trophoblast plugs. In addition, we give evidence of the presence of MMP-1 in plugs of invaded spiral arteries. The results reveal a better understanding and a closer insight into the morphological appearance of trophoblast plugs and the consequences for placental and uterine blood flow. KEYWORDS: Endoglandular trophoblast; Endovascular trophoblast; Placenta; Spiral artery; Trophoblast plug; Uterine gland

PMID 27510415

The role of syncytins in human reproduction and reproductive organ cancers

Reproduction. 2016 Aug 2. pii: REP-16-0031. [Epub ahead of print]

Soygur B1, Sati L2.


Human life begins with sperm and oocyte fusion. After fertilization, various fusion events occur during human embryogenesis and morphogenesis. For example, the fusion of trophoblastic cells constitutes a key process for normal placental development. Fusion in the placenta is facilitated by syncytin 1 and syncytin 2. These syncytin's arose from retroviral sequences that entered the primate genome 25 million and more than 40 million years ago, respectively. About 8% of the human genome consists of similar human endogenous retroviral (HERVs) sequences. Many are inactive because of mutations or deletions. However, the role of the few that remain transcriptionally active has not been fully elucidated. Syncytin proteins maintain cell-cell fusogenic activity based on env gene mediated viral cell entry. In this review, we summarize how syncytins and their receptors are involved in fusion events during human reproduction. The significance of syncytins in tumorigenesis is also discussed. PMID 27486264

The transcriptomic evolution of mammalian pregnancy: gene expression innovations in endometrial stromal fibroblasts

Genome Biol Evol. 2016 Jul 10. pii: evw168.

Kin K1, Maziarz J2, Chavan AR1, Kamat M3, Vasudevan S3, Birt A3, Emera D4, Lynch VJ5, Ott TL3, Pavlicev M6, Wagner GP7.


The endometrial stromal fibroblast (ESF) is a cell type present in the uterine lining of therian mammals. In the stem lineage of eutherian mammals ESF acquired the ability to differentiate into decidual cells in order to allow embryo implantation. We call the latter cell type "neo-ESF" in contrast to "paleo-ESF" which are homologous to eutherian ESF but are not able to decidualize. In this study we compare the transcriptomes of ESF from six therian species: opossum (Monodelphis domestica; paleo-ESF), mink, rat, rabbit, human (all neo-ESF) and cow (secondarily non-decidualizing neo-ESF). We find evidence for strong stabilizing selection on transcriptome composition suggesting that the expression of ~5,600 genes are maintained by natural selection. The evolution of neo-ESF from paleo-ESF involved the following gene expression changes: loss of expression of genes related to inflammation and immune response, lower expression of genes opposing tissue invasion, increased markers for proliferation as well as the recruitment of FOXM1, a key gene transiently expressed during decidualization. Signaling pathways also evolve rapidly and continue to evolve within eutherian lineages. In the bovine lineage, where invasiveness and decidualization was secondarily lost, we see a re-expression of genes found in opossum, most prominently WISP2, and a loss of gene expression related to angiogenesis. The data from this and previous studies supports a scenario, where the pro-inflammatory paleo-ESF was reprogrammed to express anti-inflammatory genes in response to the inflammatory stimulus coming from the implanting conceptus and thus paving the way for extended, trans-cyclic gestation. © The Author(s) 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. KEYWORDS: Eutheria; Marsupialia; cell type evolution; endometrial stromal cells; transcriptome evolution

PMID 27401177

MSX2 Induces Trophoblast Invasion in Human Placenta

PLoS One. 2016 Apr 18;11(4):e0153656. doi: 10.1371/journal.pone.0153656. eCollection 2016.

Liang H1, Zhang Q1, Lu J1, Yang G1, Tian N1, Wang X1, Tan Y1, Tan D1.


Normal implantation depends on appropriate trophoblast growth and invasion. Inadequate trophoblast invasion results in pregnancy-related disorders, such as early miscarriage and pre-eclampsia, which are dangerous to both the mother and fetus. Msh Homeobox 2 (MSX2), a member of the MSX family of homeobox proteins, plays a significant role in the proliferation and differentiation of various cells and tissues, including ectodermal organs, teeth, and chondrocytes. Recently, MSX2 was found to play important roles in the invasion of cancer cells into adjacent tissues via the epithelial-mesenchymal transition (EMT). However, the role of MSX2 in trophoblastic invasion during placental development has yet to be explored. In the present study, we detected MSX2 expression in cytotrophoblast, syncytiotrophoblast, and extravillous cytotrophoblast cells of first or third trimester human placentas via immunohistochemistry analysis. Furthermore, we found that the in vitro invasive ability of HTR8/SVneo cells was enhanced by exogenous overexpression of MSX2, and that this effect was accompanied by increased protein expression of matrix metalloproteinase-2 (MMP-2), vimentin, and β-catenin. Conversely, treatment of HTR8/SVneo cells with MSX2-specific siRNAs resulted in decreased protein expression of MMP-2, vimentin, and β-catenin, and reduced invasion levels in a Matrigel invasion test. Notably, however, treatment with the MSX2 overexpression plasmid and the MSX2 siRNAs had no effect on the mRNA expression levels of β-catenin. Meanwhile, overexpression of MSX2 and treatment with the MSX2-specific siRNA resulted in decreased and increased E-cadherin expression, respectively, in JEG-3 cells. Lastly, the protein expression levels of MSX2 were significantly lower in human pre-eclamptic placental villi than in the matched control placentas. Collectively, our results suggest that MSX2 may induce human trophoblast cell invasion, and dysregulation of MSX2 expression may be associated with pre-eclampsia. PMID 27088357

Effect of folic acid on human trophoblast health and function in vitro

Placenta. 2016 Jan;37:7-15. doi: 10.1016/j.placenta.2015.11.012. Epub 2015 Nov 27.

Ahmed T1, Fellus I2, Gaudet J3, MacFarlane AJ4, Fontaine-Bisson B5, Bainbridge SA6.


INTRODUCTION: The combined intake of folic acid (FA) from prenatal multivitamin supplements and fortified foods can result in FA intake values that exceed the tolerable upper intake level (UL). It is unclear what impact FA intake above the UL may have on the feto-placental unit. Our objective was to determine the effects of increasing concentrations of FA on trophoblast health and function in vitro. METHODS: Two human placental cell lines [HTR-8/SVneo (n = 5 experiments) and BeWo (n = 5 experiments)] and human placenta tissue explants (n = 6 experiments) were exposed to increasing concentrations of FA (2-2000 ng/mL) for 48-h. Intracellular total folate concentration, trophoblast proliferation, viability, apoptosis, placenta cell invasion and β-hCG hormone release were assessed. RESULTS: Exposure to increasing FA concentrations resulted in higher intracellular total folate in placental cell lines and tissue explants (p < 0.05); yet, only minimal effects of excess folic acid were observed on the primary indicators of placental health and function studied. Specifically, treatment with excess folic acid (2000 ng/mL) resulted in reduced cellular viability in the villous trophoblast BeWo cell line and increased rates of proliferation in the HT8-8/SVneo extravillous trophoblast cell line (p < 0.05). Further, deficient concentrations of folic acid (2 ng/mL) resulted in decreased cell viability and invasive capabilities of the HTR-8/SVneo extravillous trophoblast cell line (p < 0.05). DISCUSSION: Our results demonstrate that placental health and function may be compromised in conditions of folate deficiency, and not necessarily in conditions of excess FA. This finding supports the recommendation of prenatal folic acid supplementation in the North American population. Further work aimed at clarifying the therapeutic window of FA intake in the obstetrical population is warranted. Copyright © 2015 Elsevier Ltd. All rights reserved. KEYWORDS: Apoptosis; Folic acid; Invasion; Placenta; Proliferation; Trophoblast PMID 26748157


Isolation, purification and in vitro differentiation of cytotrophoblast cells from human term placenta

Reprod Biol Endocrinol. 2015 Jul 9;13:71. doi: 10.1186/s12958-015-0070-8.

Li L1,2, Schust DJ3.


BACKGROUND: The syncytialization of cytotrophoblast cells to syncytiotrophoblast is central to human placental transport and hormone production. Many techniques for in vitro study of this process have been proposed and new investigators to the field may find the literature in the field daunting. Here, we present a straightforward and reliable method to establish this important model using modern but readily available tools and reagents. METHODS: Villous cytotrophoblast cells are obtained from term placenta using mild enzymatic degradation, Percoll gradient centrifugation, negative magnetic cell sorting using an antibody against classical major histocompatibility complex molecules and in vitro culture on a matrix-coated growth surface. RESULTS: The purity of isolated cytotrophoblast cells exceeds 98 % as assessed by cytokeratin-7 expression using flow cytometry. Contamination by mesenchymal cells, extravillous trophoblast cells, leukocytes, Hofbauer and endothelial cells is minimized (less than 2 % when analyzed for vimentin, HLA-G, CD45, CD163 and CD31 using flow cytometry). Isolated cytotrophoblast cells began to aggregate into monolayers of mononucleated cells within about 12 h of plating. By 72 h in culture, most cytotrophoblast cells have differentiated into syncytiotrophoblast as demonstrated by a loss of intercellular E-cadherin expression upon fusion into multinucleated syncytia. After 72 h in culture, nearly every cultured cell expresses syncytiotrophoblast markers, including cytokeratin-7, human chorionic gonadotropin-β (β-hCG) and the fusion-related proteins glial cell missing-1 (GCM-1) and syncytin. CONCLUSIONS: We present an efficient and reliable method for isolating of cytotrophoblast cells with high purity and complete differentiation into syncytiotrophoblast in vitro.

PMID 26156160

OVO-like 1 regulates progenitor cell fate in human trophoblast development

Stephen J. Renaud, Damayanti Chakraborty, Clifford W. Mason, M. A. Karim Rumi, Jay L. Vivian, and Michael J. Soares

Epithelial barrier integrity is dependent on progenitor cells that either divide to replenish themselves or differentiate into a specialized epithelium. This paradigm exists in human placenta, where cytotrophoblast cells either propagate or undergo a unique differentiation program: fusion into an overlying syncytiotrophoblast. Syncytiotrophoblast is the primary barrier regulating the exchange of nutrients and gases between maternal and fetal blood and is the principal site for synthesizing hormones vital for human pregnancy. How trophoblast cells regulate their differentiation into a syncytium is not well understood. In this study, we show that the transcription factor OVO-like 1 (OVOL1), a homolog of Drosophila ovo, regulates the transition from progenitor to differentiated trophoblast cells. OVOL1 is expressed in human placenta and was robustly induced following stimulation of trophoblast differentiation. Disruption of OVOL1 abrogated cytotrophoblast fusion and inhibited the expression of a broad set of genes required for trophoblast cell fusion and hormonogenesis. OVOL1 was required to suppress genes that maintain cytotrophoblast cells in a progenitor state, including MYC, ID1, TP63, and ASCL2, and bound specifically to regions upstream of each of these genes. Our results reveal an important function of OVOL1 as a regulator of trophoblast progenitor cell fate during human trophoblast development.



  • OMIM 142871 - HLAG HLA-6.0; HLA60, T-CELL A LOCUS; TCA
    • Human leukocyte antigen (HLA)-G
    • The HLA-G gene is monomorphic and the only MHC antigen expressed on cytotrophoblast cells of placenta.
    • Extravillous trophoblasts from normal human placenta and the BeWo adherent human choriocarcinoma cell line express an unusual form of class I HLA molecule.
    • nonclassic HLA-G class I molecules in inhibiting natural killer cell function.
    • modulate the immunologic relationship between mother and fetus.
    • alternatively spliced HLA-G isoforms in first trimester trophoblast cell populations. Several alternatively spliced HLA-G mRNA isoforms, including a 14-bp polymorphism in the 3-prime UTR end (exon 8) of the HLA-G gene, are expressed at a significantly lower level than the corresponding HLA-G mRNA isoforms with the 14-bp sequence deleted. Hviid et al. (2003) suggested that this finding may have functional implications in connection with reports of aberrant HLA-G expression and reproductive success.
    • alternative splicing that generates seven HLA-G proteins.
  • UniProt P17693 338 AA
    • Involved in the presentation of foreign antigens to the immune system.
    • Plays a role in maternal tolerance of the fetus by mediating protection from the deleterious effects of natural killer cells, cytotoxic T-lymphocytes, macrophages and mononuclear cells.

<pubmed limit=5>HLAG</pubmed>

Expression and potential roles of HLA-G in human spermatogenesis and early embryonic development

PLoS One. 2014 Mar 25;9(3):e92889. doi: 10.1371/journal.pone.0092889. eCollection 2014.

Yao GD1, Shu YM2, Shi SL1, Peng ZF1, Song WY1, Jin HX1, Sun YP1.


As one of the non-classical major histocompatibility complex(MHC)-1 antigens, Human Leukocyte Antigen G (HLA-G), has been suggested as a prognostic marker to identify the embryo developmental potential. In the present study, we investigated the potential roles of HLA-G in human spermatogenesis and early embryonic development. Quantitative real-time PCR analysis revealed that HLA-G's expression was increased with increased Johnsen score in testicular tissues. There was no significant difference in HLA-G mRNA expression between testicular tissues with Johnsen score of 8-9 and normal sperm from ejaculated semen. HLA-G mRNA expression was detected in human zygotes, embryos and blastocysts but not in unfertilized oocytes. In testicular tissues where sperm was obtained by testicular sperm extraction (Johnsen score was 8 to 9), there were no correlations between HLA-G mRNA expression and fertilization, cleavage and high-quality embryo rates. At 48-72 h post-fertilization, HLA-G expression was higher in fast growing embryos. HLA-G specific siRNA injection into zygotes not only slowed down embryonic cleavage rate at 48 h post-fertilization, but also down-regulated the expression of embryo metabolism related gene (SLC2A1) and cell cycle-regulated gene (CCND2). Taken together, our findings suggested that HLA-G plays significant roles in human spermatogenesis and early embryonic development.

  • RNA Extraction - Frozen testicular tissues were diced and fully grinded in liquid nitrogen, and then mixed with lysis buffer of PureLink RNA Mini Kit (Life Technologies, Inc., Gaithersburg, MD). RNA was extracted using the PureLink RNA Mini Kit.
  • PCR primers described for HLA-G;

PMID 24667226

Immunohistochemical study of immunological markers: HLAG, CD16, CD25, CD56 and CD68 in placenta tissues in recurrent pregnancy loss

Histol Histopathol. 2014 Feb 21. [Epub ahead of print]

Papamitsou T1, Toskas A2, Papadopoulou K2, Sioga A2, Lakis S2, Chatzistamatiou M2, Economou Z3, Adriopoulou L2. Author information


Introduction: Recurrent pregnancy loss (RPL) of unknown etiology is correlated with immunological alterations during pregnancy. Normally, changes in leukocyte subpopulations and HLA expression take place in pregnant uterus in order to tolerate the semi-allogenic embryo. Objective: Our research tries to enlighten the immunological changes that take place in the uterus of women with recurrent abortions of unknown etiology during first trimester of pregnancy. Materials and methods: The miscarriage group was obtained from 25 women who miscarried between the ages of 35 to 42 years and controls consisted of 25 healthy women between the ages of 27 to 39 years, who had electively terminated their pregnancies during the first trimester of pregnancy. The abortion was processed and specimens taken were studied using immunohistochemical methods. Specimens were taken from decidua basalis and decidua parietalis. Monoclonal antibodies were used against HLAG (Human Leukocyte Antigen G), CD68( Cluster of Differentiation 68), CD56, CD16 and CD25. The results were statistically analysed with Mann-Whitney test. Results: HLA-G expression in decidua basalis from miscarriage group was found to be decreased. CD25+ cell expression was found to be invariable in deciduas from both groups. CD16+ cell and CD68 + cell expression was found to be increased in deciduas from the miscarriage group. CD56+ cell expression was found to be increased in decidua parietalis from miscarriage group. Conclusion : Several differences in the immunological profile of deciduas from RPL group were observed. Changes in feto-protective HLA-G expression and a possible implication of macrophages and NK cells were found.

PMID 24557735

HLA-G molecule

Curr Pharm Des. 2009;15(28):3318-24. Kamishikiryo J1, Maenaka K. Author information


Human leukocyte antigen-G (HLA-G) is a non-classical HLA class I molecule, which was first discovered in 1987 by Geraghty and colleagues. While classical HLA class I molecules are expressed on all nucleated cells, the expression of the HLA-G molecule is highly tissue-restricted, such as to placental trophoblast cells. HLA-G binds inhibitory receptors such as leukocyte immunoglobulin-like receptors B1 (LILRB1/ILT2/CD85j) and LILRB2 (ILT4/CD85d), which are widely expressed on immune cells, to suppress a broad range of immune responses. Thus, the expression of HLA-G in placenta protects the fetus from the maternal immune system. On the other hand, emerging studies have shown the relevance of the HLA-G molecule in pathologic conditions, such as transplantation rejection, autoimmunity, and cancer. HLA-G has other unique characteristics, in contrast with classical HLA molecules, including the existence of various forms of HLA-G: several splice variants, subunit-deficient conformations, homodimers, and their combinations have been found. In this review, we highlight the molecular basis for the tolerogenic ability of the HLA-G molecule, especially by LILR recognition of various forms of HLA-G. We also discuss the potential clinical applications of HLA-G molecules.

PMID 19860681

An alternatively spliced form of HLA-G mRNA in human trophoblasts and evidence for the presence of HLA-G transcript in adult lymphocytes

Proc Natl Acad Sci U S A. 1994 May 10;91(10):4209-13.

Kirszenbaum M1, Moreau P, Gluckman E, Dausset J, Carosella E.


The HLA-G monomorphic, nonclassical class I gene encodes the major histocompatibility complex (MHC) molecule, which is the only MHC antigen expressed on cytotrophoblast cells of placenta. In this work, we have investigated expression of the HLA-G gene in fetal tissues and adult peripheral blood cells by using a sensitive hot-start reverse transcriptase PCR technique. PCR amplification with HLA-G primers specific for exon 3 has enabled us to demonstrate an alternatively spliced form of HLA-G mRNA present in fetal first trimester trophoblasts and lacking exon 4 (HLA-G.3-5). This low abundance transcript (approximately 1:200) in comparison to full-length mRNA may encode the protein that excludes the alpha 3 domain and by conformational changes may present a different ability to bind to peptides. Moreover, expression of the HLA-G transcript was found in adult peripheral lymphocytes and equally in B- and T-cell populations. These results are discussed in the context of the fetal-maternal relationship presented by HLA-G gene products.

PMID 8183892

A human major histocompatibility complex class I gene that encodes a protein with a shortened cytoplasmic segment

Proc Natl Acad Sci U S A. 1987 Dec;84(24):9145-9.

Geraghty DE1, Koller BH, Orr HT. Author information


We have cloned genomic DNA encoding a non-HLA-A, -B, -C class I gene located within a HindIII-generated restriction fragment of 6.0 kilobase pairs. This gene, designated HLA-6.0, is as homologous to HLA-A and HLA-B as they are to each other. The HLA class I protein encoded by HLA-6.0 is similar in organization to the HLA-A-, -B-, and -C-encoded proteins except that an in-frame termination codon prevents translation of a majority of the cytoplasmic region of the HLA-6.0 polypeptide. Moreover, the promoter region of HLA-6.0 resembles the promoter region of a Qa region gene. These structural features of HLA-6.0 suggest that this non-HLA-A, -B, -C gene is a structural homolog of a murine Qa region class I gene.

PMID 3480534

HLAG Elisa Kits

Antibody Resource - HLAG Elisa Kits


  • RD194070100R sHLA-G ELISA is a sandwich enzyme immunoassay for the quantitative measurement of soluble forms of human leukocyte antigen-G (sHLA-G).
  • The total assay time is about 20 hours
  • The kit measures shedded HLA-G1 and HLA-G5 in plasma-EDTA, amniotic fluid, or cell culture supernatant Calibrator is human native protein
  • Assay format is 96 wells
  • Components of the kit are provided ready to use, concentrated or lyophilised
  • RD194070100R 96 wells (1 kit) 795 €

EXBIO Antibodies


United States Biological

  • Catalog H6098-71
  • sHLA-G ELISA is a double monoclonal sandwich enzyme immunoassay for the quantitative measurement of soluble forms of Human Leukocyte Antigen-G (sHLA-G) in amniotic fluid, cell culture supernatant and plasma or serum.


  • anti-HLA-G mAb MEM-G/9

A. Moffett (Cambridge University, Cambridge, United Kingdom).

  • mAb G233 specific for HLA-G


The effect of heat shock protein 27 on extravillous trophoblast differentiation and on eukaryotic translation initiation factor 4E expression

Mol Hum Reprod. 2014 Feb 24. [Epub ahead of print]

Sadeh-Mestechkin D1, Epstein Shochet G, Pomeranz M, Fishman A, Drucker L, Biron-Shental T, Lishner M, Tartakover Matalon S. Author information


Heat shock protein (HSP27) is expressed in human placentae. Previously, we showed that HSP27 is expressed in the villous cell column of first trimester placental explants and in extravillous trophoblast (EVT) cells. EVT differentiation is accompanied by increased motility, matrix metalloproteinase (MMP) activity, decreased proliferation and expression of specific markers such as HLAG and CD9. HSP27 regulates cell apoptosis, migration, protein stability and the availability of eukaryotic translation initiation factors, such as eukaryotic translation initiation factor 4E (eIF4E). eIF4E supports trophoblast cell proliferation and survival. We wanted to explore the effect of HSP27 silencing on trophoblast cell phenotype, EVT markers and eIF4E expression and regulators [4E-binding protein (4E-BP1) and MAP kinase-interacting kinase (MNK1)]. This study evaluated the effect of HSP27 siRNA on placental explant and HTR-8/SVneo migration, MMP activity/mRNA, cell death, cell cycle, HLAG/CD9 levels, and eIF4E and its regulators' total and phosphorylated levels. Furthermore, we evaluated HSP27 levels in placentae exposed to ribavirin, which triggers EVT differentiation. We found that HSP27 silencing increased cell death in HTR-8/SVneo and placental explants. Furthermore, it reduced HTR-8/SVneo migration and EVT outgrowth from the explants (P < 0.05), MMP2 activity and expression of EVT markers HLAG and CD9 (in placental explants and HTR-8/SVneo, respectively, P < 0.05). Induction of EVT differentiation by ribavirin elevated HSP27 levels. Finally, HSP27 silencing in both HTR-8/SVneo and placental explants reduced eIF4E levels (33 and 28%, respectively, P < 0.05) and the levels of its regulators 4E-BP1 and MNK1 (37 and 32%, respectively, done on HTR-8/SVneo only), but not their phosphorylated forms. Altogether, our results suggest that HSP27 contributes to EVT cell differentiation. KEYWORDS: HSP27, differentiation, eIF4E, placenta

PMID 24431103


Alternative protein names: Heat shock 17 kDa protein / HSP 17 / HSP27 / HSPB3 / HSPL27 / Protein 3 / Q12988 / Q9QZ57 / Q9QZ58


  • AMS.E09H0289 - Monkey

Boster Immunoleader


Sino Biological

  • minimum detectable dose of Human HSP27 was determined to be approximately 9.4 pg/ml.
  • SEK10351 5 Plates ($350)
  • double antibody kit need to coat your own plates.



The dual roles of geminin during trophoblast proliferation and differentiation

Dev Biol. 2014 Mar 1;387(1):49-63. doi: 10.1016/j.ydbio.2013.12.034. Epub 2014 Jan 9.

de Renty C1, Kaneko KJ1, Depamphilis ML2. Author information


Geminin is a protein involved in both DNA replication and cell fate acquisition. Although it is essential for mammalian preimplantation development, its role remains unclear. In one study, ablation of the geminin gene (Gmnn) in mouse preimplantation embryos resulted in apoptosis, suggesting that geminin prevents DNA re-replication, whereas in another study it resulted in differentiation of blastomeres into trophoblast giant cells (TGCs), suggesting that geminin regulates trophoblast specification and differentiation. Other studies concluded that trophoblast differentiation into TGCs is regulated by fibroblast growth factor-4 (FGF4), and that geminin is required to maintain endocycles. Here we show that ablation of Gmnn in trophoblast stem cells (TSCs) proliferating in the presence of FGF4 closely mimics the events triggered by FGF4 deprivation: arrest of cell proliferation, formation of giant cells, excessive DNA replication in the absence of DNA damage and apoptosis, and changes in gene expression that include loss of Chk1 with up-regulation of p57 and p21. Moreover, FGF4 deprivation of TSCs reduces geminin to a basal level that is required for maintaining endocycles in TGCs. Thus, geminin acts both like a component of the FGF4 signal transduction pathway that governs trophoblast proliferation and differentiation, and geminin is required to maintain endocycles. Published by Elsevier Inc. KEYWORDS: Cdkn1a/p21/Cip1, Cdkn1c/p57/Kip2, Chk1, Differentiation, Endocycles, Endoreplication, Geminin, Trophectoderm, Trophoblast giant cells, Trophoblast stem cells

PMID 24412371


Laser-assisted blastocyst dissection and subsequent cultivation of embryonic stem cells in a serum/cell free culture system: applications and preliminary results in a murine model

J Transl Med. 2006 May 8;4:20.

Tanaka N, Takeuchi T, Neri QV, Sills ES, Palermo GD. Source Center for Reproductive Medicine and Infertility, Weill Medical College of Cornell University, New York, NY 10021, USA. Abstract BACKGROUND: To evaluate embryonic stem cell (ESC) harvesting methods with an emphasis on derivation of ESC lines without feeder cells or sera. Using a murine model, laser-assisted blastocyst dissection was performed and compared to conventional immunosurgery to assess a novel laser application for inner cell mass (ICM) isolation. METHODS: Intact blastocysts or isolated ICMs generated in a standard mouse strain were plated in medium with or without serum to compare ESC harvesting efficiency. ESC derivation was also undertaken in a feeder cell-free culture system. RESULTS: Although ICM growth and dissociation was comparable irrespective of the media components, an enhanced ESC harvest was observed in our serum-free medium (p < 0.01). ESC harvest rate was not affected by ICM isolation technique but was attenuated in the feeder cell-free group. CONCLUSION: Achieving successful techniques for human ESC research is fundamentally dependent on preliminary work using experimental animals. In this study, all experimentally developed ESC lines manifested similar features to ESCs obtained from intact blastocysts in standard culture. Cell/sera free murine ESC harvest and propagation are feasible procedures for an embryology laboratory and await refinements for translation to human medical research.

PMID 16681851

TROMA-I Antibody

Antigen: cytokeratin 8, Endo-A

Contributor: Brulet, P. / Kemler, R.

Cells Available: Yes

Host Species: rat

Isotype: IgG2a, kappa light chain

Antigen Species: mouse

Species Tested: mouse, human

Immunoblotting: Yes

References: Proc. Nat'l. Acad. Sci. 77, 4113-4117.; J. Embryol. Exp. Morph. 64, 45-60.; Exp. Cell Res. 154(1), 315-319.; J. Cell Sci. 109, 2789-2800.; J. Comp. Path. 119, 177-181.; Dev. Biol. 253, 258-263.; Int. J. Cancer 113, 525-532.; Cell 138, 592-603.


A disintegrin and metalloproteinase 12 (ADAM12) localizes to invasive trophoblast, promotes cell invasion and directs column outgrowth in early placental development

Mol Hum Reprod. 2014 Mar;20(3):235-49. doi: 10.1093/molehr/gat084. Epub 2013 Nov 15. Aghababaei M1, Perdu S, Irvine K, Beristain AG. Author information


During pregnancy, stromal- and vascular-remodeling trophoblasts serve critical roles in directing placental development acquiring pro-invasive characteristics. The A Disintegrin and Metalloproteinase (ADAM) family of multifunctional proteins direct cellular processes across multiple organ systems via their intrinsic catalytic, cell adhesive and intracellular signaling properties. ADAM12, existing as two distinct splice variants (ADAM12L and ADAM12S), is highly expressed in the human placenta and promotes cell migration and invasion in several tumor cell lines; however, its role in trophoblast biology is unknown. In this study, ADAM12 was localized to anchoring trophoblast columns in first trimester placentas and to highly invasive extracellular matrix-degrading trophoblasts in placental villous explants. The importance of ADAM12 in directing trophoblast invasion was tested using loss-of and gain-of-function strategies, where siRNA-directed knockdown of ADAM12 inhibited trophoblast cell invasion while over-expression promoted migration and invasion in two trophoblastic cell models. In placental villous explant cultures, siRNA-directed loss of ADAM12 significantly dampened trophoblast column outgrowth. Additionally, we provide functional evidence for the ADAM12S variant in promoting trophoblast invasion and column outgrowth through a mechanism requiring its catalytic activity. This is the first study to assign a function for ADAM12 in trophoblast biology, where ADAM12 may play a central role regulating the behavior of invasive trophoblast subsets in early pregnancy. This study also underlines the importance of ADAM12L and ADAM12S in directing cell motility in normal developmental processes outside of cancer, specifically highlighting a potentially important function of ADAM12S in directing early placental development. KEYWORDS: A Disintegrin and Metalloproteinase 12, cell invasion, placenta, protease, trophoblast

PMID 24243624

10 Most Recent

Note - This sub-heading shows an automated computer PubMed search using the listed sub-heading term. References appear in this list based upon the date of the actual page viewing. Therefore the list of references do not reflect any editorial selection of material based on content or relevance. In comparison, references listed on the content page and discussion page (under the publication year sub-headings) do include editorial selection based upon relevance and availability. (More? Pubmed Most Recent)


<pubmed limit=5>Trophoblast</pubmed>


<pubmed limit=5>Syncitiotrophoblast</pubmed>


Establishment of Trophoblast Stem Cells under Defined Culture Conditions in Mice

PLoS One. 2014 Sep 9;9(9):e107308. doi: 10.1371/journal.pone.0107308. eCollection 2014.

Ohinata Y1, Tsukiyama T2.


The inner cell mass (ICM) and trophoblast cell lineages duet early embryonic development in mammals. After implantation, the ICM forms the embryo proper as well as some extraembryonic tissues, whereas the trophoectoderm (TE) exclusively forms the fetal portion of the placenta and the trophoblast giant cells. Although embryonic stem (ES) cells can be derived from ICM in cultures of mouse blastocysts in the presence of LIF and/or combinations of small-molecule chemical compounds, and the undifferentiated pluripotent state can be stably maintained without use of serum and feeder cells, defined culture conditions for derivation and maintenance of undifferentiated trophoblast stem (TS) cells have not been established. Here, we report that addition of FGF2, activin A, XAV939, and Y27632 are necessary and sufficient for derivation of TS cells from both of E3.5 blastocysts and E6.5 early postimplantation extraembryonic ectoderm. Moreover, the undifferentiated TS cell state can be stably maintained in chemically defined culture conditions. Cells derived in this manner expressed TS cell marker genes, including Eomes, Elf5, Cdx2, Klf5, Cdh1, Esrrb, Sox2, and Tcfap2c; differentiated into all trophoblast subtypes (trophoblast giant cells, spongiotrophoblast, and labyrinthine trophoblast) in vitro; and exclusively contributed to trophoblast lineages in chimeric animals. This delineation of minimal requirements for derivation and self-renewal provides a defined platform for precise description and dissection of the molecular state of TS cells.

PMID 25203285

Intermediate conductance Ca2+-activated k+ channels modulate human placental trophoblast syncytialization

PLoS One. 2014 Mar 3;9(3):e90961. doi: 10.1371/journal.pone.0090961. eCollection 2014.

Díaz P, Wood AM, Sibley CP, Greenwood SL. Author information


Regulation of human placental syncytiotrophoblast renewal by cytotrophoblast migration, aggregation/fusion and differentiation is essential for successful pregnancy. In several tissues, these events are regulated by intermediate conductance Ca2+-activated K+ channels (IKCa), in part through their ability to regulate cell volume. We used cytotrophoblasts in primary culture to test the hypotheses that IKCa participate in the formation of multinucleated syncytiotrophoblast and in syncytiotrophoblast volume homeostasis. Cytotrophoblasts were isolated from normal term placentas and cultured for 66 h. This preparation recreates syncytiotrophoblast formation in vivo, as mononucleate cells (15 h) fuse into multinucleate syncytia (66 h) concomitant with elevated secretion of human chorionic gonadotropin (hCG). Cells were treated with the IKCa inhibitor TRAM-34 (10 µM) or activator DCEBIO (100 µM). Culture medium was collected to measure hCG secretion and cells fixed for immunofluorescence with anti-IKCa and anti-desmoplakin antibodies to assess IKCa expression and multinucleation respectively. K+ channel activity was assessed by measuring 86Rb efflux at 66 h. IKCa immunostaining was evident in nucleus, cytoplasm and surface of mono- and multinucleate cells. DCEBIO increased 86Rb efflux 8.3-fold above control and this was inhibited by TRAM-34 (85%; p<0.0001). Cytotrophoblast multinucleation increased 12-fold (p<0.05) and hCG secretion 20-fold (p<0.05), between 15 and 66 h. Compared to controls, DCEBIO reduced multinucleation by 42% (p<0.05) and hCG secretion by 80% (p<0.05). TRAM-34 alone did not affect cytotrophoblast multinucleation or hCG secretion. Hyposmotic solution increased 86Rb efflux 3.8-fold (p<0.0001). This effect was dependent on extracellular Ca2+, inhibited by TRAM-34 and 100 nM charybdotoxin (85% (p<0.0001) and 43% respectively) but unaffected by 100 nM apamin. In conclusion, IKCa are expressed in cytotrophoblasts and their activation inhibits the formation of multinucleated cells in vitro. IKCa are stimulated by syncytiotrophoblast swelling implicating a role in syncytiotrophoblast volume homeostasis. Inappropriate activation of IKCa in pathophysiological conditions could compromise syncytiotrophoblast turnover and volume homeostasis in pregnancy disease.

PMID 24595308

IgG expression in trophoblasts derived from placenta and gestational trophoblastic disease and its role in regulating invasion

Immunol Res. 2014 Jan 28. [Epub ahead of print]

Yang M, Ha C, Liu D, Xu Y, Ma Y, Liu Y, Nian Y. Author information

Abstract Immunoglobulin G (IgG) is an important humoral immune factor, which plays a role in innate immunity of the fetus. IgG immunoreactivity was often seen in trophoblasts of placenta. Traditionally, IgG in trophoblasts was believed to be transported from the maternal blood through neonatal Fc receptor (FcRn). Here, we explored the phenomenon of IgG expression and its role in regulating invasion in trophoblasts derived from normal placenta and gestational trophoblastic disease (GTD). IgG expression was detected with an emphasis on mRNA transcripts by using reverse transcription-polymerase chain reaction and hybridization in situ, besides evaluated at the protein level with immunohistochemistry and immunofluorescence. The migration and attachment of normal trophoblast cell line (TEV-1) and choriocarcinoma cell line (JAR) were inhibited with down-regulation of IgG expression. Methotrexate promoted the differentiation of JAR cell line; however, it had little effect on the differentiation of TEV-1 cell line. IgG expression, migration, and attachment of JAR and TEV-1 cell lines were decreased in the presence of methotrexate. Furthermore, statistical analysis showed that the differences in migration and attachment were significant (P < 0.05) for JAR cell line, while no significant difference was found for TEV-1 cell line. Collectively, these results confirmed that with the progression from normal placenta to GTD, the expression of IgG was increased in trophoblasts, which might actively promote the migration and attachment of trophoblasts as an important regulating factor.

PMID 24469916


The proprotein convertase furin is required for trophoblast syncytialization

Cell Death Dis. 2013 Apr 18;4:e593. doi: 10.1038/cddis.2013.106.

Zhou Z, Zhang Q, Lu X, Wang R, Wang H, Wang YL, Zhu C, Lin HY, Wang H. Source 1] State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China [2] Graduate School of the Chinese Academy of Sciences, Beijing 100039, China. Abstract The multinucleated syncytial trophoblast, which forms the outermost layer of the placenta and serves multiple functions, is differentiated from and maintained by cytotrophoblast cell fusion. Deficiencies in syncytial trophoblast differentiation or maintenance likely contribute to intrauterine growth restriction and pre-eclampsia, two common gestational diseases. The cellular and molecular mechanisms governing trophoblast syncytialization are poorly understood. We report here that the proprotein convertase furin is highly expressed in syncytial trophoblast in the first trimester human placentas, and expression of furin in the syncytiotrophoblast is significantly lower in the placentas from pre-eclamptic patients as compared with their gestational age-matched control placentas. Using multiple experimental models including induced fusion of choriocarcinoma BeWo cells and spontaneous fusion of primary cultured cytotrophoblast cells or placental explants, we demonstrate that cytotrophoblast cell fusion and syncytialization are accompanied by furin expression. Furin-specific siRNAs or inhibitors inhibit cell fusion in BeWo cells, as well as trophoblast syncytialization in human placental explants. Furthermore, type 1 IGF receptor (IGF1R) is indicated in this study as a substrate of furin, and processing of IGF1R by furin is an essential mechanism for syncytialization. Finally, using lentivirus-mediated RNAi targeting to mouse trophectoderm, we demonstrate that furin function is required for the development of syncytiotrophoblast structure in the labyrinth layer, as well as for normal embryonic development.

PMID 23598405

Reduced syncytin-1 expression levels in placental syndromes correlates with epigenetic hypermethylation of the ERVW-1 promoter region

PLoS One. 2013;8(2):e56145. doi: 10.1371/journal.pone.0056145. Epub 2013 Feb 14.

Ruebner M, Strissel PL, Ekici AB, Stiegler E, Dammer U, Goecke TW, Faschingbauer F, Fahlbusch FB, Beckmann MW, Strick R. Source University-Clinic Erlangen, Department of Gynaecology and Obstetrics, Laboratory for Molecular Medicine, Erlangen, Germany.


Terminal differentiation of villous cytotrophoblasts (CT) ends in formation of the multinucleated syncytiotrophoblast representing the fetal-maternal interface. Aberrations during this cell-fusion process are associated with Intrauterine Growth Restriction (IUGR), Preeclampsia (PE) and High Elevated Liver and Low Platelets (HELLP) Syndrome. Syncytin-1, the envelope gene of the human Endogenous Retrovirus ERVW-1, is one of the most important genes involved in cell-fusion and showed decreased gene expression during these pathological pregnancies. The aim of this study was to determine the methylation pattern of the entire promoter of ERVW-1 and to correlate these findings with the expression profile of Syncytin-1 in the placental syndromes. 14 isolated villous cytotrophoblasts from control (n = 3), IUGR (n = 3), PE (n = 3), PE/IUGR (n = 3) and HELLP/IUGR (n = 2) placentae were used to determine the mean methylation level (ML) for the ERVW-1 promoter region. ML rose significantly from 29% in control CTs to 49% in IUGR, 53% in PE, 47% in PE/IUGR and 64% in HELLP/IUGR indicating an epigenetic down-regulation of Syncytin-1 by promoter hypermethylation. DNA demethylation of the trophoblast like cell lines BeWo, JEG-3 and JAR with 5-AZA-2'desoxycytidine (AZA) showed an increased Syncytin-1 expression and fusion ability in all cell lines. Promoter activity of the 5'LTR could be inhibited by hypermethylation 42-fold using a luciferase based reporter-gene assay. Finally overexpression of the methyltransferases DNMT3a and LSH could be responsible for a decreased Syncytin-1 expression by promoter hypermethylation of ERVW-1. Our study linked decreased Syncytin-1 expression to an epigenetic hypermethylation of the entire promoter of ERVW-1. Based on our findings we are predicting a broad aberrant epigenetic DNA-methylation pattern in pathological placentae affecting placentogenesis, but also the development of the fetus and the mother during pregnancy.

PMID 23457515


Epigenetic features of the mouse trophoblast

Reprod Biomed Online. 2012 Jul;25(1):21-30. doi: 10.1016/j.rbmo.2012.01.012. Epub 2012 Jan 25.

Rugg-Gunn PJ. Source Epigenetics Programme, The Babraham Institute, Babraham Research Campus, Cambridge, UK. Abstract Trophoblast cells are required for the growth and survival of the fetus during pregnancy, and failure to maintain appropriate trophoblast regulation is associated with placental insufficiencies and intrauterine growth restriction. Development of the trophoblast lineage is mediated by interactions between genetic and epigenetic factors. This review will focus on new insights that have been gained from analysis of mouse models into the epigenetic mechanisms that are required for the early establishment of the trophoblast lineage and for the development of specialized cell types of the fetal placenta. In particular, the importance of DNA methylation, 5-hydroxymethylcytosine and histone modifications in orchestrating trophoblast gene expression and functional outcome will be discussed. These insights are beginning to be extended towards human studies and initial results suggest that the causes and consequences of a variety of placental pathologies are related to epigenetic processes. Furthermore, the epigenetic landscape that regulates trophoblast cells seems to be particularly vulnerable to perturbation during development. This has major implications for diet and other environmental factors during pregnancy. Copyright © 2012 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.

PMID 22578826

Inhibition of histone deacetylase activity in human endometrial stromal cells promotes extracellular matrix remodelling and limits embryo invasion

PLoS One. 2012;7(1):e30508. Epub 2012 Jan 26.

Estella C, Herrer I, Atkinson SP, Quiñonero A, Martínez S, Pellicer A, Simón C. Source Fundación Instituto Valenciano de Infertilidad, Valencia University, and Instituto Universitario IVI/INCLIVA, Valencia, Spain.


Invasion of the trophoblast into the maternal decidua is regulated by both the trophoectoderm and the endometrial stroma, and entails the action of tissue remodeling enzymes. Trophoblast invasion requires the action of metalloproteinases (MMPs) to degrade extracellular matrix (ECM) proteins and in turn, decidual cells express tissue inhibitors of MMPs (TIMPs). The balance between these promoting and restraining factors is a key event for the successful outcome of pregnancy. Gene expression is post-transcriptionally regulated by histone deacetylases (HDACs) that unpacks condensed chromatin activating gene expression. In this study we analyze the effect of histone acetylation on the expression of tissue remodeling enzymes and activity of human endometrial stromal cells (hESCs) related to trophoblast invasion control. Treatment of hESCs with the HDAC inhibitor trichostatin A (TSA) increased the expression of TIMP-1 and TIMP-3 while decreased MMP-2, MMP-9 and uPA and have an inhibitory effect on trophoblast invasion. Moreover, histone acetylation is detected at the promoters of TIMP-1 and TIMP-3 genes in TSA-treated. In addition, in an in vitro decidualized hESCs model, the increase of TIMP-1 and TIMP-3 expression is associated with histone acetylation at the promoters of these genes. Our results demonstrate that histone acetylation disrupt the balance of ECM modulators provoking a restrain of trophoblast invasion. These findings are important as an epigenetic mechanism that can be used to control trophoblast invasion.

PMID 22291969 [PubMed - indexed for MEDLINE] PMCID: PMC3266920

Early Expression of Pregnancy-Specific Glycoprotein 22 (PSG22) by Trophoblast Cells Modulates Angiogenesis in Mice

Biol Reprod. 2012 Mar 14. [Epub ahead of print]

Blois S, Tirado-Gonzalez I, Wu J, Barrientos G, Johnson B, Warren J, Freitag N, Klapp B, Irmak S, Ergün S, Dveksler G.


Mouse and human pregnancy-specific glycoproteins (PSG) are known to exert immunomodulatory functions during pregnancy by inducing maternal leukocytes to secrete anti-inflammatory cytokines that promote a tolerogenic decidual microenvironment. Many such anti-inflammatory mediators also function as pro-angiogenic factors, which, along with the reported association of -murine PSG - with the uterine vasculature, suggest that PSG may contribute to the vascular adaptations necessary for successful implantation and placental development. We observed that PSG22 is strongly expressed around the embryonic crypt on gestation day (Gd) 5.5, indicating that trophoblast giant cells are the main source of PSG22 during the early stages of pregnancy. PSG22 treatment up-regulated the secretion of transforming growth factor beta 1 (TGFB1) and vascular endothelial growth factor A (VEGFA) in murine macrophages, uterine dendritic cells and natural killer cells. A possible role of PSGs in uteroplacental angiogenesis is further supported by the finding that incubation of endothelial cells with PSG22 resulted in the formation of tubes in the presence and absence of VEGFA. We determined that PSG22, like human PSG1 and murine PSG17 and 23, binds to the heparan sulfate chains in syndecans. Therefore, our findings indicate that despite the independent evolution and expansion of human and rodent PSG, members in both families have conserved functions, which include their ability to induce anti-inflammatory cytokines and pro-angiogenic factors as well as to induce the formation of capillary structures by endothelial cells. In summary, our results indicate that PSG22, the most abundant PSG expressed during mouse early pregnancy, is likely a major contributor to the establishment of a successful pregnancy.

PMID 22423048


Trisomy 21- affected placentas highlight prerequisite factors for human trophoblast fusion and differentiation

Int J Dev Biol. 2010;54(2-3):475-82.

Malassiné A, Frendo JL, Evain-Brion D. INSERM, U767, Paris, France.

Abstract Trophoblastic cell fusion is one essential step of the human trophoblast differentiation pathway and is a multifactorial and dynamic process finely regulated and still poorly known. Disturbances of syncytiotrophoblast formation are observed in numerous pathological clinical conditions such as preeclampsia, intrauterine growth retardation and trisomy 21. In this review, we summarize current knowledge of the different membrane proteins directly involved in trophoblastic cell fusion, which we identified by using the physiological model of primary culture of villous trophoblastic cells. Connexin 43 and gap junctional intercellular communication point to the role of molecular exchanges through connexin channels preceding membrane fusion. Zona occludens-1, which can interact with connexin 43, is also directly involved in trophoblast fusion. The recently identified fusogenic membrane retroviral envelop glycoproteins syncytin 1 (encoded by the HERV-W gene) and syncytin 2 (encoded by the FRD gene) and their receptors are major factors involved in human placental development . We describe the increasing number of factors promoting or inhibiting trophoblast fusion and differentiation and emphasize the role of human chorionic gonadotropin (hCG) and its receptor. Indeed, in trisomy 21 the dynamic process leading to membrane fusion is impaired due to an abnormal hCG signaling. This abnormal trophoblast fusion and differentiation in trisomy 21-affected placenta is reversible in vitro. Trisomy 21 trophoblastic cell culture may therefore be useful to identify the possible large number of prerequisite factors involved in trophoblast fusion, the limiting step of trophoblast differentiation.

PMID 19876835

Development and function of trophoblast giant cells in the rodent placenta

Int J Dev Biol. 2010;54(2-3):341-54.

Hu D, Cross JC.

Department of Comparative Biology and Experimental Medicine, Faculty of Veterinary Medicine and Graduate Program in Biochemistry and Molecular Biology, University of Calgary, Calgary, Alberta, Canada. Abstract Trophoblast giant cells (TGCs) are the first cell type to terminally differentiate during embryogenesis and are of vital importance for implantation and modulation of post-implantation placentation. TGCs are mononuclear and polyploid but are heterogenous and dynamic. At least four different subtypes of TGCs are present within the mature placenta that have distinct cell lineage origins. The development of TGCs is complex and requires transition from the mitotic to the endoreduplication cell cycle and is regulated by a wide variety of factors. During early gestation, TGCs mediate blastocyst attachment and invasion into the uterine epithelium, regulate uterus decidualization, and anatomosis with maternal blood spaces to form the transient yolk sac placenta. During later gestation, TGCs secrete a wide array of hormones and paracrine factors, including steroid hormones and Prolactin-related cytokines, to target the maternal physiological systems for proper maternal adaptations to pregnancy and the fetal-maternal interface to ensure vasculature remodeling. The large number of mouse mutants with defects in TGC development and function are giving us significant new insights into the biology of these fascinating cells.

PMID 19876834

Int J Dev Biol.

Vol. 54 Nos. 2/3 (2010) Placenta

Trophoblast phagocytic program: roles in different placental systems

Int J Dev Biol. 2010;54(2-3):495-505.

Bevilacqua E, Hoshida MS, Amarante-Paffaro A, Albieri-Borges A, Zago Gomes S.

University of São Paulo, SP, Brazil. Abstract Although not belonging to the class of professional phagocytes, in many species trophoblast cells exhibit intense phagocytic activity. The complete range of physiological functions of trophoblast phagocytosis has not yet been fully characterized. Close association between the trophoblast and nutrition was determined many years ago. Hubrecht (1889) when proposing for the first time the name trophoblast to the external layer of the blastocyst, directly established the nutritive significance of this embryonic layer. Indeed, histotrophic phagocytosis, i.e. the internalization of maternal cells and secreted materials, is considered an important function of the trophoblast before the completion of the placenta. Recently, however, unexpected characteristics of the trophoblast have significantly enhanced our understanding of this process. Roles in acquisition of space for embryo development, in tissue remodeling during implantation and placentation and in defense mechanisms are highlighting how this cellular activity may be relevant for the maternal-fetal relationship beyond its nutritional function.

PMID 19757392


Function of caspase-14 in trophoblast differentiation

Reprod Biol Endocrinol. 2009 Sep 14;7:98.

White LJ, Declercq W, Arfuso F, Charles AK, Dharmarajan AM.

School of Anatomy and Human Biology, Faculty of Life and Physical Sciences, The University of Western Australia, Perth, Western Australia, Australia. Abstract BACKGROUND: Within the human placenta, the cytotrophoblast consists of a proliferative pool of progenitor cells which differentiate to replenish the overlying continuous, multi-nucleated syncytiotrophoblast, which forms the barrier between the maternal and fetal tissues. Disruption to trophoblast differentiation and function may result in impaired fetal development and preeclampsia. Caspase-14 expression is limited to barrier forming tissues. It promotes keratinocyte differentiation by cleaving profilaggrin to stabilise keratin intermediate filaments, and indirectly providing hydration and UV protection. However its role in the trophoblast remains unexplored.

METHODS: Using RNA Interference the reaction of control and differentiating trophoblastic BeWo cells to suppressed caspase-14 was examined for genes pertaining to hormonal, cell cycle and cytoskeletal pathways.

RESULTS: Transcription of hCG, KLF4 and cytokeratin-18 were increased following caspase-14 suppression suggesting a role for caspase-14 in inhibiting their pathways. Furthermore, hCG, KLF4 and cytokeratin-18 protein levels were disrupted.

CONCLUSION: Since expression of these molecules is normally increased with trophoblast differentiation, our results imply that caspase-14 inhibits trophoblast differentiation. This is the first functional study of this unusual member of the caspase family in the trophoblast, where it has a different function than in the epidermis. This knowledge of the molecular underpinnings of trophoblast differentiation may instruct future therapies of trophoblast disease.

PMID 19747408

Intrauterine fate of invasive trophoblast cells

Placenta. 2009 May;30(5):457-63. Epub 2009 Apr 2.

Rosario GX, Ain R, Konno T, Soares MJ.

Institute of Maternal-Fetal Biology, Division of Cancer and Developmental Biology, Department of Pathology and Laboratory of Medicine, University of Kansas Medical Center, Kansas City, KS 66160, USA. Abstract Invasion of trophoblast cells into the uterine spiral arteries and the uterine wall is characteristic of hemochorial placentation. In the rat, trophoblast cells penetrate through the uterine decidua and well into the metrial gland. In this report, we examined the fate of these invasive trophoblast cells following parturition. Invasive trophoblast endocrine cells were retained in the postpartum mesometrial uterus in the rat. The demise of invasive trophoblast cells was followed by the appearance of differentiated smooth muscle cells surrounding blood vessels previously lined by invasive trophoblast cells and an infiltration of macrophages. Regulation of intrauterine trophoblast cell fate was investigated following premature removal of the fetus or removal of the fetus and chorioallantoic placenta. The presence of the fetus affected the distribution of invasive trophoblast cells within the uterus but did not negatively impact their survival. Premature removal of all chorioallantoic placentas and associated fetuses from a uterus resulted in extensive removal of intrauterine trophoblast cells. In summary, the postpartum demise of intrauterine invasive trophoblast cells is a dynamic developmental event regulated in part by the removal of trophic signals emanating from the chorioallantoic placenta.

PMID 19344949

Trophoblast infection with Chlamydia pneumoniae and adverse pregnancy outcomes associated with placental dysfunction

Am J Obstet Gynecol. 2009 May;200(5):526.e1-7.

Gomez LM, Parry S.

Maternal and Child Research Program, Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, University of Pennsylvania School of Medicine, Philadelphia, PA, USA. Abstract OBJECTIVE: We sought to determine whether Chlamydia pneumoniae impairs invasive trophoblast function and is associated with preeclampsia.

STUDY DESIGN: We conducted cell viability and invasion assays using primary extravillous trophoblast cells isolated from first-trimester placentas. We performed a case-control study to identify C pneumoniae in trophoblast cells dissected by laser capture microscopy from placentas in women with severe preeclampsia and control subjects who delivered at term.

RESULTS: Trophoblast cell viability and invasion through extracellular matrices were decreased after infection with C pneumoniae (both P < .05). C pneumoniae DNA was detected in trophoblast cells in 15/48 cases but only 3/30 controls (odds ratio, 4.1; P = .02). Positive and negative controls yielded expected results.

CONCLUSION: C pneumoniae infection can reduce trophoblast invasion into the uterine wall and is associated with preeclampsia. Further investigation of the mechanisms by which C pneumoniae induces trophoblast dysfunction, and the identification of therapies to prevent adverse outcomes attributed to trophoblast dysfunction, are warranted.

PMID 19375572

Chlamydophila pneumoniae is a species of Chlamydophila bacteria that infects humans and is a major cause of pneumonia.

While dysferlin and myoferlin are coexpressed in the human placenta, only dysferlin expression is responsive to trophoblast fusion in model systems

Biol Reprod. 2009 Jul;81(1):33-9. Epub 2009 Feb 18. Robinson JM, Ackerman WE 4th, Behrendt NJ, Vandre DD.

Departments of Physiology and Cell Biology and Obstetrics and Gynecology, The Ohio State University, Columbus, Ohio 43210, USA. Abstract The syncytiotrophoblast is a specialized epithelium derived from mononuclear cytotrophoblasts that fuse to form this extensive syncytium. Dysferlin is expressed primarily in the apical plasma membrane of the syncytiotrophoblast in the human placenta. Here, we document the presence of another member of the ferlin family, myoferlin, in the placenta and show that it too is expressed primarily in the syncytiotrophoblast. Additionally, we examined the trophoblastic cell lines BeWo, JAR, and JEG-3 for the expression of dysferlin and myoferlin and determined the extent to which their expression was modulated by cell-cell fusion. In trophoblastic cells, there was a positive correlation between cell fusion and increased dysferlin expression but not myoferlin expression. Regarding expression, these trophoblastic cell lines recapitulate the distribution of dysferlin in mononuclear cytotrophoblasts and the syncytiotrophoblast in vivo.

PMID 19228595


HOXA13 Is essential for placental vascular patterning and labyrinth endothelial specification

PLoS Genet. 2008 May 16;4(5):e1000073.

Shaut CA, Keene DR, Sorensen LK, Li DY, Stadler HS.

Department of Molecular and Medical Genetics, Oregon Health & Science University, Portland, Oregon, United States of America. Abstract In eutherian mammals, embryonic growth and survival is dependent on the formation of the placenta, an organ that facilitates the efficient exchange of oxygen, nutrients, and metabolic waste between the maternal and fetal blood supplies. Key to the placenta's function is the formation of its vascular labyrinth, a series of finely branched vessels whose molecular ontogeny remains largely undefined. In this report, we demonstrate that HOXA13 plays an essential role in labyrinth vessel formation. In the absence of HOXA13 function, placental endothelial cell morphology is altered, causing a loss in vessel wall integrity, edema of the embryonic blood vessels, and mid-gestational lethality. Microarray analysis of wild-type and mutant placentas revealed significant changes in endothelial gene expression profiles. Notably, pro-vascular genes, including Tie2 and Foxf1, exhibited reduced expression in the mutant endothelia, which also exhibited elevated expression of genes normally expressed in lymphatic or sinusoidal endothelia. ChIP analysis of HOXA13-DNA complexes in the placenta confirmed that HOXA13 binds the Tie2 and Foxf1 promoters in vivo. In vitro, HOXA13 binds sequences present in the Tie2 and Foxf1 promoters with high affinity (K(d) = 27-42 nM) and HOXA13 can use these bound promoter regions to direct gene expression. Taken together, these findings demonstrate that HOXA13 directly regulates Tie2 and Foxf1 in the placental labyrinth endothelia, providing a functional explanation for the mid-gestational lethality exhibited by Hoxa13 mutant embryos as well as a novel transcriptional program necessary for the specification of the labyrinth vascular endothelia.

PMID 18483557


The first trimester human trophoblast cell line ACH-3P: a novel tool to study autocrine/paracrine regulatory loops of human trophoblast subpopulations--TNF-alpha stimulates MMP15 expression

BMC Dev Biol. 2007 Dec 19;7:137.

Hiden U1, Wadsack C, Prutsch N, Gauster M, Weiss U, Frank HG, Schmitz U, Fast-Hirsch C, Hengstschläger M, Pötgens A, Rüben A, Knöfler M, Haslinger P, Huppertz B, Bilban M, Kaufmann P, Desoye G. Author information

Abstract BACKGROUND: The trophoblast compartment of the placenta comprises various subpopulations with distinct functions. They interact among each other by secreted signals thus forming autocrine or paracrine regulatory loops. We established a first trimester trophoblast cell line (ACH-3P) by fusion of primary human first trimester trophoblasts (week 12 of gestation) with a human choriocarcinoma cell line (AC1-1). RESULTS: Expression of trophoblast markers (cytokeratin-7, integrins, matrix metalloproteinases), invasion abilities and transcriptome of ACH-3P closely resembled primary trophoblasts. Morphology, cytogenetics and doubling time was similar to the parental AC1-1 cells. The different subpopulations of trophoblasts e.g., villous and extravillous trophoblasts also exist in ACH-3P cells and can be immuno-separated by HLA-G surface expression. HLA-G positive ACH-3P display pseudopodia and a stronger expression of extravillous trophoblast markers. Higher expression of insulin-like growth factor II receptor and human chorionic gonadotropin represents the basis for the known autocrine stimulation of extravillous trophoblasts. CONCLUSION: We conclude that ACH-3P represent a tool to investigate interaction of syngeneic trophoblast subpopulations. These cells are particularly suited for studies into autocrine and paracrine regulation of various aspects of trophoblast function. As an example a novel effect of TNF-alpha on matrix metalloproteinase 15 in HLA-G positive ACH-3P and explants was found.

PMID 18093301 [PubMed - indexed for MEDLINE] PMCID: PMC2263055


The phagocytic activity of human first trimester extravillous trophoblast

First paper for Trophoblast Line SGHPL-4.

Hum Reprod. 1998 Oct;13(1O):2941-9.

Choy MY1, Manyonda IT.


It has been suggested previously that phagocytic activity in the human placenta is confined to cells of the macrophage lineage. However, earlier studies were hampered by the paucity and poor viability of cells inherent in primary trophoblast cell cultures, contamination by other cell types which themselves have phagocytic activity, lack of reliable markers of trophoblasts, and by limitations of methods available to demonstrate unequivocally the internalization of particulate material. We have overcome these limitations by using: (i) DNA transfection to provide unlimited supplies of pure trophoblast cell lines; (ii) human placental lactogen as a marker unique to trophoblast; and (iii) confocal microscopy to demonstrate unequivocally the intracellular locality of phagocytosed material. We found that both untransfected primary culture extravillous trophoblast cells, as well as the cell lines, had the capacity to phagocytose sheep red blood cells, Staphylococcus aureus and baker's yeast cells, and that this activity was inhibited by cytochalasin B and by culture at 4 degrees C. Phagocytic activity in trophoblast cells was less avid than that seen in a professional phagocyte. In physiological and pathological situations where tissue remodelling occurs, such as the rapid turnover in the periodontal ligament or during inflammation, epithelial cells and other cells that are not considered professional phagocytes actively phagocytose components of the extracellular matrix. We postulate that phagocytosis by human trophoblasts may play an important role in the extensive tissue remodelling that occurs during trophoblastic invasion of the decidua.

PMID 9804259