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Sugimoto J, Schust DJ, Sugimoto M, Jinno Y, Kudo Y. Controlling Trophoblast Cell Fusion in the Human Placenta-Transcriptional Regulation of Suppressyn, an Endogenous Inhibitor of Syncytin-1. Biomolecules 2023; 13:1627. [PMID: 38002309 PMCID: PMC10668956 DOI: 10.3390/biom13111627] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Revised: 10/24/2023] [Accepted: 11/03/2023] [Indexed: 11/26/2023] Open
Abstract
Cell fusion in the placenta is tightly regulated. Suppressyn is a human placental endogenous retroviral protein that inhibits the profusogenic activities of another well-described endogenous retroviral protein, syncytin-1. In this study, we aimed to elucidate the mechanisms underlying suppressyn's placenta-specific expression. We identified the promoter region and a novel enhancer region for the gene encoding suppressyn, ERVH48-1, and examined their regulation via DNA methylation and their responses to changes in the oxygen concentration. Like other endogenous retroviral genes, the ERVH48-1 promoter sequence is found within a characteristic retroviral 5' LTR sequence. The novel enhancer sequence we describe here is downstream of this LTR sequence (designated EIEs: ERV internal enhancer sequence) and governs placental expression. The placenta-specific expression of ERVH48-1 is tightly controlled by DNA methylation and further regulated by oxygen concentration-dependent, hypoxia-induced transcription factors (HIF1α and HIF2α). Our findings highlight the involvement of (1) tissue specificity through DNA methylation, (2) expression specificity through placenta-specific enhancer regions, and (3) the regulation of suppressyn expression in differing oxygen conditions by HIF1α and HIF2α. We suggest that these regulatory mechanisms are central to normal and abnormal placental development, including the development of disorders of pregnancy involving altered oxygenation, such as preeclampsia, pregnancy-induced hypertension, and fetal growth restriction.
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Affiliation(s)
- Jun Sugimoto
- Department of Obstetrics and Gynecology, Graduate School of Medical Sciences, Hiroshima University, Hiroshima 734-8551, Japan (Y.K.)
| | - Danny J. Schust
- Department of Obstetrics and Gynecology, Duke University, Durham, NC 27710, USA
| | - Makiko Sugimoto
- Department of Obstetrics and Gynecology, Graduate School of Medical Sciences, Hiroshima University, Hiroshima 734-8551, Japan (Y.K.)
| | - Yoshihiro Jinno
- Department of Molecular Biology, University of the Ryukyus, Okinawa 903-0215, Japan
| | - Yoshiki Kudo
- Department of Obstetrics and Gynecology, Graduate School of Medical Sciences, Hiroshima University, Hiroshima 734-8551, Japan (Y.K.)
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Zhou H, Zhao C, Wang P, Yang W, Zhu H, Zhang S. Regulators involved in trophoblast syncytialization in the placenta of intrauterine growth restriction. Front Endocrinol (Lausanne) 2023; 14:1107182. [PMID: 36798658 PMCID: PMC9927020 DOI: 10.3389/fendo.2023.1107182] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Accepted: 01/20/2023] [Indexed: 02/04/2023] Open
Abstract
Placental dysfunction refers to the insufficiency of placental perfusion and chronic hypoxia during early pregnancy, which impairs placental function and causes inadequate supply of oxygen and nutrients to the fetus, affecting fetal development and health. Fetal intrauterine growth restriction, one of the most common outcomes of pregnancy-induced hypertensions, can be caused by placental dysfunction, resulting from deficient trophoblast syncytialization, inadequate trophoblast invasion and impaired vascular remodeling. During placental development, cytotrophoblasts fuse to form a multinucleated syncytia barrier, which supplies oxygen and nutrients to meet the metabolic demands for fetal growth. A reduction in the cell fusion index and the number of nuclei in the syncytiotrophoblast are found in the placentas of pregnancies complicated by IUGR, suggesting that the occurrence of IUGR may be related to inadequate trophoblast syncytialization. During the multiple processes of trophoblasts syncytialization, specific proteins and several signaling pathways are involved in coordinating these events and regulating placental function. In addition, epigenetic modifications, cell metabolism, senescence, and autophagy are also involved. Study findings have indicated several abnormally expressed syncytialization-related proteins and signaling pathways in the placentas of pregnancies complicated by IUGR, suggesting that these elements may play a crucial role in the occurrence of IUGR. In this review, we discuss the regulators of trophoblast syncytialization and their abnormal expression in the placentas of pregnancies complicated by IUGR.
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Affiliation(s)
- Hanjing Zhou
- Assisted Reproduction Unit, Department of Obstetrics and Gynecology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, China
- Key Laboratory of Reproductive Dysfunction Management of Zhejiang Province, Hangzhou, China
| | - Chenqiong Zhao
- Assisted Reproduction Unit, Department of Obstetrics and Gynecology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, China
- Key Laboratory of Reproductive Dysfunction Management of Zhejiang Province, Hangzhou, China
| | - Peixin Wang
- Assisted Reproduction Unit, Department of Obstetrics and Gynecology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, China
- Key Laboratory of Reproductive Dysfunction Management of Zhejiang Province, Hangzhou, China
| | - Weijie Yang
- Assisted Reproduction Unit, Department of Obstetrics and Gynecology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, China
- Key Laboratory of Reproductive Dysfunction Management of Zhejiang Province, Hangzhou, China
| | - Haiyan Zhu
- Assisted Reproduction Unit, Department of Obstetrics and Gynecology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, China
- Key Laboratory of Reproductive Dysfunction Management of Zhejiang Province, Hangzhou, China
- *Correspondence: Songying Zhang, ; Haiyan Zhu,
| | - Songying Zhang
- Assisted Reproduction Unit, Department of Obstetrics and Gynecology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, China
- Key Laboratory of Reproductive Dysfunction Management of Zhejiang Province, Hangzhou, China
- *Correspondence: Songying Zhang, ; Haiyan Zhu,
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Zhou X, Zhou M, Zheng M, Tian S, Yang X, Ning Y, Li Y, Zhang S. Polyploid giant cancer cells and cancer progression. Front Cell Dev Biol 2022; 10:1017588. [PMID: 36274852 PMCID: PMC9581214 DOI: 10.3389/fcell.2022.1017588] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Accepted: 09/21/2022] [Indexed: 12/02/2022] Open
Abstract
Polyploid giant cancer cells (PGCCs) are an important feature of cellular atypia, the detailed mechanisms of their formation and function remain unclear. PGCCs were previously thought to be derived from repeated mitosis/cytokinesis failure, with no intrinsic ability to proliferate and divide. However, recently, PGCCs have been confirmed to have cancer stem cell (CSC)-like characteristics, and generate progeny cells through asymmetric division, which express epithelial-mesenchymal transition-related markers to promote invasion and migration. The formation of PGCCs can be attributed to multiple stimulating factors, including hypoxia, chemotherapeutic reagents, and radiation, can induce the formation of PGCCs, by regulating the cell cycle and cell fusion-related protein expression. The properties of CSCs suggest that PGCCs can be induced to differentiate into non-tumor cells, and produce erythrocytes composed of embryonic hemoglobin, which have a high affinity for oxygen, and thereby allow PGCCs survival from the severe hypoxia. The number of PGCCs is associated with metastasis, chemoradiotherapy resistance, and recurrence of malignant tumors. Targeting relevant proteins or signaling pathways related with the formation and transdifferentiation of adipose tissue and cartilage in PGCCs may provide new strategies for solid tumor therapy.
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Affiliation(s)
- Xinyue Zhou
- Graduate School, Tianjin Medical University, Tianjin, China
| | - Mingming Zhou
- Graduate School, Tianjin Medical University, Tianjin, China
| | - Minying Zheng
- Department of Pathology, Tianjin Union Medical Center, Tianjin, China
| | - Shifeng Tian
- Graduate School, Tianjin Medical University, Tianjin, China
| | - Xiaohui Yang
- Nankai University School of Medicine, Nankai University, Tianjin, China
| | - Yidi Ning
- Nankai University School of Medicine, Nankai University, Tianjin, China
| | - Yuwei Li
- Department of Colorectal Surgery, Tianjin Union Medical Center, Tianjin, China
| | - Shiwu Zhang
- Department of Pathology, Tianjin Union Medical Center, Tianjin, China
- *Correspondence: Shiwu Zhang,
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Zhang H, Ma H, Yang X, Fan L, Tian S, Niu R, Yan M, Zheng M, Zhang S. Cell Fusion-Related Proteins and Signaling Pathways, and Their Roles in the Development and Progression of Cancer. Front Cell Dev Biol 2022; 9:809668. [PMID: 35178400 PMCID: PMC8846309 DOI: 10.3389/fcell.2021.809668] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Accepted: 12/22/2021] [Indexed: 12/16/2022] Open
Abstract
Cell fusion is involved in many physiological and pathological processes, including gamete binding, and cancer development. The basic processes of cell fusion include membrane fusion, cytoplasmic mixing, and nuclear fusion. Cell fusion is regulated by different proteins and signaling pathways. Syncytin-1, syncytin-2, glial cell missing 1, galectin-1 and other proteins (annexins, myomaker, myomerger etc.) involved in cell fusion via the cyclic adenosine-dependent protein kinase A, mitogen-activated protein kinase, wingless/integrase-1, and c-Jun N-terminal kinase signaling pathways. In the progression of malignant tumors, cell fusion is essential during the organ-specific metastasis, epithelial-mesenchymal transformation, the formation of cancer stem cells (CSCs), cancer angiogenesis and cancer immunity. In addition, diploid cells can be induced to form polyploid giant cancer cells (PGCCs) via cell fusion under many kinds of stimuli, including cobalt chloride, chemotherapy, radiotherapy, and traditional Chinese medicine. PGCCs have CSC-like properties, and the daughter cells derived from PGCCs have a mesenchymal phenotype and exhibit strong migration, invasion, and proliferation abilities. Therefore, exploring the molecular mechanisms of cell fusion can enable us better understand the development of malignant tumors. In this review, the basic process of cell fusion and its significance in cancer is discussed.
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Affiliation(s)
- Hao Zhang
- Graduate School, Tianjin University of Traditional Chinese Medicine, Tianjin, China
| | - Hong Ma
- Tianjin Union Medical Center, Nankai University, Tianjin, China
| | - Xiaohui Yang
- Nankai University School of Medicine, Nankai University, Tianjin, China
| | - Linlin Fan
- Graduate School, Tianjin University of Traditional Chinese Medicine, Tianjin, China
| | - Shifeng Tian
- Graduate School, Tianjin Medical University, Tianjin, China
| | - Rui Niu
- Graduate School, Tianjin University of Traditional Chinese Medicine, Tianjin, China
| | - Man Yan
- Graduate School, Tianjin University of Traditional Chinese Medicine, Tianjin, China
| | - Minying Zheng
- Tianjin Union Medical Center, Nankai University, Tianjin, China
| | - Shiwu Zhang
- Tianjin Union Medical Center, Nankai University, Tianjin, China
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Štafl K, Trávníček M, Kučerová D, Pecnová Ľ, Krchlíková V, Gáliková E, Stepanets V, Hejnar J, Trejbalová K. Heterologous avian system for quantitative analysis of Syncytin-1 interaction with ASCT2 receptor. Retrovirology 2021; 18:15. [PMID: 34158079 PMCID: PMC8220723 DOI: 10.1186/s12977-021-00558-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Accepted: 06/05/2021] [Indexed: 12/29/2022] Open
Abstract
Background Human Syncytin-1 is a placentally-expressed cell surface glycoprotein of retroviral origin. After interaction with ASCT2, its cellular receptor, Syncytin-1 triggers cell–cell fusion and formation of a multinuclear syncytiotrophoblast layer of the placenta. The ASCT2 receptor is a multi-spanning membrane protein containing a protruding extracellular part called region C, which has been suggested to be a retrovirus docking site. Precise identification of the interaction site between ASCT2 and Syncytin-1 is challenging due to the complex structure of ASCT2 protein and the background of endogenous ASCT2 gene in the mammalian genome. Chicken cells lack the endogenous background and, therefore, can be used to set up a system with surrogate expression of the ASCT2 receptor. Results We have established a retroviral heterologous chicken system for rapid and reliable assessment of ectopic human ASCT2 protein expression. Our dual-fluorescence system proved successful for large-scale screening of mutant ASCT2 proteins. Using this system, we demonstrated that progressive deletion of region C substantially decreased the amount of ASCT2 protein. In addition, we implemented quantitative assays to determine the interaction of ASCT2 with Syncytin-1 at multiple levels, which included binding of the soluble form of Syncytin-1 to ASCT2 on the cell surface and a luciferase-based assay to evaluate cell–cell fusions that were triggered by Syncytin-1. Finally, we restored the envelope function of Syncytin-1 in a replication-competent retrovirus and assessed the infection of chicken cells expressing human ASCT2 by chimeric Syncytin-1-enveloped virus. The results of the quantitative assays showed that deletion of the protruding region C did not abolish the interaction of ASCT2 with Syncytin-1. Conclusions We present here a heterologous chicken system for effective assessment of the expression of transmembrane ASCT2 protein and its interaction with Syncytin-1. The system profits from the absence of endogenous ASCT2 background and implements the quantitative assays to determine the ASCT2-Syncytin-1 interaction at several levels. Using this system, we demonstrated that the protruding region C was essential for ASCT2 protein expression, but surprisingly, not for the interaction with Syncytin-1 glycoprotein. Graphical abstract ![]()
Supplementary Information The online version contains supplementary material available at 10.1186/s12977-021-00558-0.
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Affiliation(s)
- Kryštof Štafl
- Institute of Molecular Genetics, Czech Academy of Sciences, Vídeňská 1083, 14220, Prague 4, Czech Republic.,Faculty of Science, Charles University, Albertov 6, 12800, Prague 2, Czech Republic
| | - Martin Trávníček
- Institute of Molecular Genetics, Czech Academy of Sciences, Vídeňská 1083, 14220, Prague 4, Czech Republic
| | - Dana Kučerová
- Institute of Molecular Genetics, Czech Academy of Sciences, Vídeňská 1083, 14220, Prague 4, Czech Republic
| | - Ľubomíra Pecnová
- Institute of Molecular Genetics, Czech Academy of Sciences, Vídeňská 1083, 14220, Prague 4, Czech Republic
| | - Veronika Krchlíková
- Institute of Molecular Genetics, Czech Academy of Sciences, Vídeňská 1083, 14220, Prague 4, Czech Republic
| | - Eliška Gáliková
- Institute of Molecular Genetics, Czech Academy of Sciences, Vídeňská 1083, 14220, Prague 4, Czech Republic
| | - Volodymyr Stepanets
- Institute of Molecular Genetics, Czech Academy of Sciences, Vídeňská 1083, 14220, Prague 4, Czech Republic
| | - Jiří Hejnar
- Institute of Molecular Genetics, Czech Academy of Sciences, Vídeňská 1083, 14220, Prague 4, Czech Republic.
| | - Kateřina Trejbalová
- Institute of Molecular Genetics, Czech Academy of Sciences, Vídeňská 1083, 14220, Prague 4, Czech Republic.
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Aplin JD, Jones CJP. Cell dynamics in human villous trophoblast. Hum Reprod Update 2021; 27:904-922. [PMID: 34125187 DOI: 10.1093/humupd/dmab015] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Revised: 04/22/2021] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Villous cytotrophoblast (vCTB) is a precursor cell population that supports the development of syncytiotrophoblast (vSTB), the high surface area barrier epithelium of the placental villus, and the primary interface between maternal and fetal tissue. In light of increasing evidence that the placenta can adapt to changing maternal environments or, under stress, can trigger maternal disease, we consider what properties of these cells empower them to exert a controlling influence on pregnancy progression and outcome. OBJECTIVE AND RATIONALE How are cytotrophoblast proliferation and differentiation regulated in the human placental villus to allow for the increasing demands of the fetal and environmental challenges and stresses that may arise during pregnancy? SEARCH METHODS PubMed was interrogated using relevant keywords and word roots combining trophoblast, villus/villous, syncytio/syncytium, placenta, stem, transcription factor (and the individual genes), signalling, apoptosis, autophagy (and the respective genes) from 1960 to the present. Since removal of trophoblast from its tissue environment is known to fundamentally change cell growth and differentiation kinetics, research that relied exclusively on cell culture has not been the main focus of this review, though it is mentioned where appropriate. Work on non-human placenta is not systematically covered, though mention is made where relevant hypotheses have emerged. OUTCOMES The synthesis of data from the literature has led to a new hypothesis for vCTB dynamics. We propose that a reversible transition can occur from a reserve population in G0 to a mitotically active state. Cells from the in-cycle population can then differentiate irreversibly to intermediate cells that leave the cycle and turn on genes that confer the capacity to fuse with the overlying vSTB as well as other functions associated with syncytial barrier and transport function. We speculate that alterations in the rate of entry to the cell cycle, or return of cells in the mitotic fraction to G0, can occur in response to environmental challenge. We also review evidence on the life cycle of trophoblast from the time that fusion occurs, and point to gaps in knowledge of how large quantities of fetal DNA arrive in maternal circulation. We critique historical methodology and make a case for research to re-address questions about trophoblast lifecycle and dynamics in normal pregnancy and the common diseases of pre-eclampsia and fetal growth restriction, where altered trophoblast kinetics have long been postulated. WIDER IMPLICATIONS The hypothesis requires experimental testing, moving research away from currently accepted methodology towards a new standard that includes representative cell and tissue sampling, assessment of cell cycle and differentiation parameters, and robust classification of cell subpopulations in villous trophoblast, with due attention to gestational age, maternal and fetal phenotype, disease and outcome.
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Affiliation(s)
- John D Aplin
- Maternal and Fetal Health, University of Manchester, Manchester Academic Health Sciences Centre, St Mary's Hospital, Manchester, UK
| | - Carolyn J P Jones
- Maternal and Fetal Health, University of Manchester, Manchester Academic Health Sciences Centre, St Mary's Hospital, Manchester, UK
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Aplin JD, Myers JE, Timms K, Westwood M. Tracking placental development in health and disease. Nat Rev Endocrinol 2020; 16:479-494. [PMID: 32601352 DOI: 10.1038/s41574-020-0372-6] [Citation(s) in RCA: 162] [Impact Index Per Article: 40.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 05/15/2020] [Indexed: 12/14/2022]
Abstract
Pre-eclampsia and fetal growth restriction arise from disorders of placental development and have some shared mechanistic features. Initiation is often rooted in the maldevelopment of a maternal-placental blood supply capable of providing for the growth requirements of the fetus in later pregnancy, without exerting undue stress on maternal body systems. Here, we review normal development of a placental bed with a safe and adequate blood supply and a villous placenta-blood interface from which nutrients and oxygen can be extracted for the growing fetus. We consider disease mechanisms that are intrinsic to the maternal environment, the placenta or the interaction between the two. Systemic signalling from the endocrine placenta targets the maternal endothelium and multiple organs to adjust metabolism for an optimal pregnancy and later lactation. This signalling capacity is skewed when placental damage occurs and can deliver a dangerous pathogenic stimulus. We discuss the placental secretome including glycoproteins, microRNAs and extracellular vesicles as potential biomarkers of disease. Angiomodulatory mediators, currently the only effective biomarkers, are discussed alongside non-invasive imaging approaches to the prediction of disease risk. Identifying the signs of impending pathology early enough to intervene and ameliorate disease in later pregnancy remains a complex and challenging objective.
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Affiliation(s)
- John D Aplin
- Maternal and Fetal Health Group, Manchester Academic Health Sciences Centre, St Mary's Hospital, Manchester, UK.
| | - Jenny E Myers
- Maternal and Fetal Health Group, Manchester Academic Health Sciences Centre, St Mary's Hospital, Manchester, UK
| | - Kate Timms
- Lydia Becker Institute of Inflammation and Immunology, The University of Manchester, Manchester, UK
| | - Melissa Westwood
- Maternal and Fetal Health Group, Manchester Academic Health Sciences Centre, St Mary's Hospital, Manchester, UK
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Farah O, Nguyen C, Tekkatte C, Parast MM. Trophoblast lineage-specific differentiation and associated alterations in preeclampsia and fetal growth restriction. Placenta 2020; 102:4-9. [PMID: 33218578 DOI: 10.1016/j.placenta.2020.02.007] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Revised: 02/06/2020] [Accepted: 02/09/2020] [Indexed: 12/26/2022]
Abstract
The human placenta is a poorly-understood organ, but one that is critical for proper development and growth of the fetus in-utero. The epithelial cell type that contributes to primary placental functions is called "trophoblast," including two main subtypes, villous and extravillous trophoblast. Cytotrophoblast and syncytiotrophoblast comprise the villous compartment and contribute to gas and nutrient exchange, while extravillous trophoblast invade and remodel the uterine wall and vessels, in order to supply maternal blood to the growing fetus. Abnormal differentiation of trophoblast contributes to placental dysfunction and is associated with complications of pregnancy, including preeclampsia (PE) and fetal growth restriction (FGR). This review describes what is known about the cellular organization of the placenta during both normal development and in the setting of PE/FGR. It also explains known trophoblast lineage-specific markers and pathways regulating their differentiation, and how these are altered in the setting of PE/FGR, focusing on studies which have used human placental tissues. Finally, it also highlights remaining questions and needed resources to advance this field.
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Affiliation(s)
- Omar Farah
- Department of Pathology, University of California San Diego, La Jolla, CA, 92093, USA; Sanford Consortium for Regenerative Medicine, University of California San Diego, La Jolla, CA, 92093, USA
| | - Calvin Nguyen
- Department of Pathology, University of California San Diego, La Jolla, CA, 92093, USA; Sanford Consortium for Regenerative Medicine, University of California San Diego, La Jolla, CA, 92093, USA
| | - Chandana Tekkatte
- Sanford Consortium for Regenerative Medicine, University of California San Diego, La Jolla, CA, 92093, USA; Department of Obstetrics, Gynecology, and Reproductive Sciences, University of California San Diego, La Jolla, CA, 92093, USA
| | - Mana M Parast
- Department of Pathology, University of California San Diego, La Jolla, CA, 92093, USA; Sanford Consortium for Regenerative Medicine, University of California San Diego, La Jolla, CA, 92093, USA.
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Wakeland AK, Soncin F, Moretto-Zita M, Chang CW, Horii M, Pizzo D, Nelson KK, Laurent LC, Parast MM. Hypoxia Directs Human Extravillous Trophoblast Differentiation in a Hypoxia-Inducible Factor-Dependent Manner. THE AMERICAN JOURNAL OF PATHOLOGY 2017; 187:767-780. [PMID: 28167044 DOI: 10.1016/j.ajpath.2016.11.018] [Citation(s) in RCA: 89] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Revised: 11/11/2016] [Accepted: 11/29/2016] [Indexed: 01/12/2023]
Abstract
Villous cytotrophoblasts are epithelial stem cells of the early human placenta, able to differentiate either into syncytiotrophoblasts in floating chorionic villi or extravillous trophoblasts (EVTs) at the anchoring villi. The signaling pathways regulating differentiation into these two lineages are incompletely understood. The bulk of placental growth and development in the first trimester occurs under low oxygen tension. One major mechanism by which oxygen regulates cellular function is through the hypoxia-inducible factor (HIF), a transcription factor complex stabilized under low oxygen tension to mediate cellular responses, including cell fate decisions. HIF is known to play a role in trophoblast differentiation in rodents; however, its role in human trophoblast differentiation is poorly understood. Using RNA profiling of sorted populations of primary first-trimester trophoblasts, we evaluated the first stage of EVT differentiation, the transition from epidermal growth factor receptor+ villous cytotrophoblasts into human leukocyte antigen-G+ proximal column EVT (pcEVT) and identified hypoxia as a major pcEVT-associated pathway. Using primary cytotrophoblasts, we determined that culture in low oxygen directs differentiation preferentially toward human leukocyte antigen-G+ pcEVT, and that an intact HIF complex is required for this process. Finally, using global RNA profiling, we identified integrin-linked kinase and associated cytoskeletal remodeling and adhesion to be among HIF-dependent pcEVT-associated signaling pathways. Taken together, we propose that oxygen regulates EVT differentiation through HIF-dependent modulation of various cell adhesion and morphology-related pathways.
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Affiliation(s)
- Anna K Wakeland
- Department of Pathology, University of California San Diego, La Jolla, California; Sanford Consortium for Regenerative Medicine, University of California San Diego, La Jolla, California
| | - Francesca Soncin
- Department of Pathology, University of California San Diego, La Jolla, California; Sanford Consortium for Regenerative Medicine, University of California San Diego, La Jolla, California
| | - Matteo Moretto-Zita
- Department of Pathology, University of California San Diego, La Jolla, California; Sanford Consortium for Regenerative Medicine, University of California San Diego, La Jolla, California
| | - Ching-Wen Chang
- Department of Pathology, University of California San Diego, La Jolla, California; Sanford Consortium for Regenerative Medicine, University of California San Diego, La Jolla, California
| | - Mariko Horii
- Department of Pathology, University of California San Diego, La Jolla, California; Sanford Consortium for Regenerative Medicine, University of California San Diego, La Jolla, California
| | - Don Pizzo
- Department of Pathology, University of California San Diego, La Jolla, California
| | - Katharine K Nelson
- Department of Pathology, University of California San Diego, La Jolla, California; Sanford Consortium for Regenerative Medicine, University of California San Diego, La Jolla, California
| | - Louise C Laurent
- Sanford Consortium for Regenerative Medicine, University of California San Diego, La Jolla, California; Department of Reproductive Medicine, University of California San Diego, La Jolla, California
| | - Mana M Parast
- Department of Pathology, University of California San Diego, La Jolla, California; Sanford Consortium for Regenerative Medicine, University of California San Diego, La Jolla, California.
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10
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Roberts RM, Green JA, Schulz LC. The evolution of the placenta. Reproduction 2016; 152:R179-89. [PMID: 27486265 DOI: 10.1530/rep-16-0325] [Citation(s) in RCA: 111] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Accepted: 08/01/2016] [Indexed: 01/23/2023]
Abstract
The very apt definition of a placenta is coined by Mossman, namely apposition or fusion of the fetal membranes to the uterine mucosa for physiological exchange. As such, it is a specialized organ whose purpose is to provide continuing support to the developing young. By this definition, placentas have evolved within every vertebrate class other than birds. They have evolved on multiple occasions, often within quite narrow taxonomic groups. As the placenta and the maternal system associate more intimately, such that the conceptus relies extensively on maternal support, the relationship leads to increased conflict that drives adaptive changes on both sides. The story of vertebrate placentation, therefore, is one of convergent evolution at both the macromolecular and molecular levels. In this short review, we first describe the emergence of placental-like structures in nonmammalian vertebrates and then transition to mammals themselves. We close the review by discussing the mechanisms that might have favored diversity and hence evolution of the morphology and physiology of the placentas of eutherian mammals.
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Affiliation(s)
- R Michael Roberts
- C.S. Bond Life Sciences CenterUniversity of Missouri, Columbia, Missouri, USA Division of Animal SciencesUniversity of Missouri, Columbia, Missouri, USA
| | - Jonathan A Green
- Division of Animal SciencesUniversity of Missouri, Columbia, Missouri, USA
| | - Laura C Schulz
- Department of ObstetricsGynecology and Women's Health, University of Missouri School of Medicine, Columbia, Missouri, USA
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Xu J, Sivasubramaniyam T, Yinon Y, Tagliaferro A, Ray J, Nevo O, Post M, Caniggia I. Aberrant TGFβ Signaling Contributes to Altered Trophoblast Differentiation in Preeclampsia. Endocrinology 2016; 157:883-99. [PMID: 26653761 DOI: 10.1210/en.2015-1696] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
TGFβ has been implicated in preeclampsia, but its intracellular signaling via phosphorylated mothers against decapentaplegic (SMADs) and SMAD-independent proteins in the placenta remains elusive. Here we show that TGFβ receptor-regulated SMAD2 was activated (Ser(465/467) phosphorylation) in syncytiotrophoblast and proliferating extravillous trophoblast cells of first-trimester placenta, whereas inhibitory SMAD7 located primarily to cytotrophoblast cells. SMAD2 phosphorylation decreased with advancing gestation, whereas SMAD7 expression increased and shifted to syncytiotrophoblasts toward term. Additionally, we found that the TGFβ SMAD-independent signaling via partitioning defective protein 6 (PARD6)/Smad ubiquitylation regulatory factor was activated at approximately 10-12 weeks of gestation in cytotrophoblast and extravillous trophoblast cells comprising the anchoring column. Placentae from early-onset, but not late-onset, preeclampsia exhibited elevated SMAD2 phosphorylation and SMAD7 levels. Whereas PARD6 expression increased and SMURF1 levels decreased in preeclamptic placentae, their association increased. SMAD2 phosphorylation by TGFβ in villous explants and BeWo cells resulted in a reduction of Glial cell missing-1 (GCM1) and fusogenic protein syncytin-1 while increasing cell cycle regulators cyclin E-1 (CCNE1) and cyclin-dependent kinase 4. SMAD7 abrogated the proliferative effects of TGFβ. CCNE1 levels were increased in preeclamptic placentae, whereas GCM1 was markedly reduced. In addition, TGFβ treatment increased the association of PARD6 and SMURF1 and down-regulated Ras homolog gene family, member A (RHOA) GTPase in JEG3 cells. In a wound assay, TGFβ treatment increased the association of PARD6 and SMURF1 and triggered JEG3 cell migration through increased cellular protrusions. Taken together, our data indicate that TGFβ signaling via both SMAD2/7 and PARD6/SMURF1 pathways plays a role in trophoblast growth and differentiation. Altered SMAD regulation of GCM1 and CCNE1 and aberrant expression/activation of PARD6/SMURF1 may contribute to the pathogenesis of preeclampsia by affecting cellular pathways associated with this disorder.
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Affiliation(s)
- Jing Xu
- Lunenfeld-Tanenbaum Research Institute (J.X., T.S., A.T., J.R., I.C.), Mt Sinai Hospital, Toronto, Ontario, Canada M5T 3H7; Departments of Obstetrics and Gynecology (Y.Y., O.N., I.C.), Physiology (T.S., J.R., M.P., I.C.), and Pediatrics (M.P.), University of Toronto, Toronto, Ontario, Canada; and Institute of Medical Science (M.P.), The Hospital for Sick Children, Toronto, Ontario, Canada M5G 1X8
| | - Tharini Sivasubramaniyam
- Lunenfeld-Tanenbaum Research Institute (J.X., T.S., A.T., J.R., I.C.), Mt Sinai Hospital, Toronto, Ontario, Canada M5T 3H7; Departments of Obstetrics and Gynecology (Y.Y., O.N., I.C.), Physiology (T.S., J.R., M.P., I.C.), and Pediatrics (M.P.), University of Toronto, Toronto, Ontario, Canada; and Institute of Medical Science (M.P.), The Hospital for Sick Children, Toronto, Ontario, Canada M5G 1X8
| | - Yoav Yinon
- Lunenfeld-Tanenbaum Research Institute (J.X., T.S., A.T., J.R., I.C.), Mt Sinai Hospital, Toronto, Ontario, Canada M5T 3H7; Departments of Obstetrics and Gynecology (Y.Y., O.N., I.C.), Physiology (T.S., J.R., M.P., I.C.), and Pediatrics (M.P.), University of Toronto, Toronto, Ontario, Canada; and Institute of Medical Science (M.P.), The Hospital for Sick Children, Toronto, Ontario, Canada M5G 1X8
| | - Andrea Tagliaferro
- Lunenfeld-Tanenbaum Research Institute (J.X., T.S., A.T., J.R., I.C.), Mt Sinai Hospital, Toronto, Ontario, Canada M5T 3H7; Departments of Obstetrics and Gynecology (Y.Y., O.N., I.C.), Physiology (T.S., J.R., M.P., I.C.), and Pediatrics (M.P.), University of Toronto, Toronto, Ontario, Canada; and Institute of Medical Science (M.P.), The Hospital for Sick Children, Toronto, Ontario, Canada M5G 1X8
| | - Jocelyn Ray
- Lunenfeld-Tanenbaum Research Institute (J.X., T.S., A.T., J.R., I.C.), Mt Sinai Hospital, Toronto, Ontario, Canada M5T 3H7; Departments of Obstetrics and Gynecology (Y.Y., O.N., I.C.), Physiology (T.S., J.R., M.P., I.C.), and Pediatrics (M.P.), University of Toronto, Toronto, Ontario, Canada; and Institute of Medical Science (M.P.), The Hospital for Sick Children, Toronto, Ontario, Canada M5G 1X8
| | - Ori Nevo
- Lunenfeld-Tanenbaum Research Institute (J.X., T.S., A.T., J.R., I.C.), Mt Sinai Hospital, Toronto, Ontario, Canada M5T 3H7; Departments of Obstetrics and Gynecology (Y.Y., O.N., I.C.), Physiology (T.S., J.R., M.P., I.C.), and Pediatrics (M.P.), University of Toronto, Toronto, Ontario, Canada; and Institute of Medical Science (M.P.), The Hospital for Sick Children, Toronto, Ontario, Canada M5G 1X8
| | - Martin Post
- Lunenfeld-Tanenbaum Research Institute (J.X., T.S., A.T., J.R., I.C.), Mt Sinai Hospital, Toronto, Ontario, Canada M5T 3H7; Departments of Obstetrics and Gynecology (Y.Y., O.N., I.C.), Physiology (T.S., J.R., M.P., I.C.), and Pediatrics (M.P.), University of Toronto, Toronto, Ontario, Canada; and Institute of Medical Science (M.P.), The Hospital for Sick Children, Toronto, Ontario, Canada M5G 1X8
| | - Isabella Caniggia
- Lunenfeld-Tanenbaum Research Institute (J.X., T.S., A.T., J.R., I.C.), Mt Sinai Hospital, Toronto, Ontario, Canada M5T 3H7; Departments of Obstetrics and Gynecology (Y.Y., O.N., I.C.), Physiology (T.S., J.R., M.P., I.C.), and Pediatrics (M.P.), University of Toronto, Toronto, Ontario, Canada; and Institute of Medical Science (M.P.), The Hospital for Sick Children, Toronto, Ontario, Canada M5G 1X8
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Lu X, He Y, Zhu C, Wang H, Chen S, Lin HY. Twist1 is involved in trophoblast syncytialization by regulating GCM1. Placenta 2016; 39:45-54. [PMID: 26992674 DOI: 10.1016/j.placenta.2016.01.008] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Revised: 12/21/2015] [Accepted: 01/08/2016] [Indexed: 12/21/2022]
Abstract
INTRODUCTION The multinucleated syncytiotrophoblast (STB) is maintained and regenerated by the fusion of underlying cytotrophoblast cells (CTBs) and is responsible for a number of functions in the human placenta. Deficiencies in this structure may result in pregnancy-associated diseases. However, the detailed mechanisms underlying trophoblast syncytialization await further investigation. METHODS The location of the transcription factor Twist1 in human placental tissues was identified by immunohistochemistry. The expression of Twist1 and glial cells missing-1 (GCM1) was evaluated by qPCR or western blotting in two cell-fusion models including forskolin-induced fusion of BeWo cells and spontaneous syncytialization of CTBs. The key role of Twist1 in trophoblast differentiation was identified using BeWo cells transfected with Twist1-specific siRNA. We investigated the effect of hypoxia on the expression of Twist1 and GCM1 in primary CTBs cultured with 2% oxygen. The Twist1 binding region in the GCM1 gene was detected by chromatin-immunoprecipitation. RESULTS Twist1 was expressed in human placental tissues, and the expression of Twist1 and GCM1 increased in a time-dependent manner during spontaneous syncytialization of primary CTBs and forskolin-induced fusion of BeWo cells. A reduction in Twist1 and GCM1 expression was observed under hypoxic conditions and was accompanied by inhibition of trophoblast syncytialization. Moreover, siRNA-mediated silencing of Twist1 resulted in inhibition of BeWo cells fusion and down-regulation of GCM1 expression. Furthermore, Twist1 was found to bind to the E-box-enriched region in intron 2 of the GCM1 gene during forskolin-induced fusion of BeWo cells. DISCUSSION The above results suggest that Twist1 is required during trophoblast syncytialization. Twist1 may promote trophoblast syncytialization by regulating the expression of GCM1.
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Affiliation(s)
- Xiaoyin Lu
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, PR China; University of Chinese Academy of Sciences, Beijing, 100039, PR China
| | - Yuxia He
- Center for Reproductive Medicine, Department of Gynecology and Obstetrics, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, PR China; State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, PR China
| | - Cheng Zhu
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, PR China
| | - Hongmei Wang
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, PR China
| | - Shiling Chen
- Center for Reproductive Medicine, Department of Gynecology and Obstetrics, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, PR China.
| | - Hai-Yan Lin
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, PR China.
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An integrative view on the physiology of human early placental villi. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2013; 114:33-48. [PMID: 24291663 DOI: 10.1016/j.pbiomolbio.2013.11.007] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2013] [Accepted: 11/20/2013] [Indexed: 01/08/2023]
Abstract
The placenta is an indispensable organ for intrauterine protection, development and growth of the embryo and fetus. It provides tight contact between mother and conceptus, enabling the exchange of gas, nutrients and waste products. The human placenta is discoidal in shape, and bears a hemo-monochorial interface as well as villous materno-fetal interdigitations. Since Peter Medawar's astonishment to the paradoxical nature of the mother-fetus relationship in 1953, substantial knowledge in the domain of placental physiology has been gathered. In the present essay, an attempt has been made to build an integrated understanding of morphological dynamics, cell biology, and functional aspects of genomic and proteomic expression of human early placental villous trophoblast cells followed by a commentary on the future directions of research in this field.
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Sivasubramaniyam T, Garcia J, Tagliaferro A, Melland-Smith M, Chauvin S, Post M, Todros T, Caniggia I. Where polarity meets fusion: role of Par6 in trophoblast differentiation during placental development and preeclampsia. Endocrinology 2013; 154:1296-309. [PMID: 23341197 DOI: 10.1210/en.2012-1823] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Trophoblast cell fusion is a prerequisite for proper human placental development. Herein we examined the contribution of Par6 (Partitioning defective protein 6), a key regulator of cell polarity, to trophoblast cell fusion in human placental development. During early placentation, Par6 localized to nuclei of cytotrophoblast cells but with advancing gestation Par6 shifted its localization to the cytoplasm and apical brush border of the syncytium. Exposure of primary isolated trophoblasts to 3% O(2) resulted in elevated Par6 expression, maintenance of tight junction marker ZO-1 at cell boundaries, and decreased fusogenic syncytin 1 expression compared with cells cultured at 20% O(2). Treatment of choriocarcinoma BeWo cells with forskolin, a known inducer of fusion, increased syncytin 1 expression but decreased that of Par6 and ZO-1. Par6 overexpression in the presence of forskolin maintained ZO-1 at cell boundaries while decreasing syncytin 1 levels. In contrast, silencing of Par6 disrupted ZO-1 localization at cell boundaries and altered the expression and distribution of acetylated α-tubulin. Par6 expression was elevated in preeclamptic placentas relative to normotensive preterm controls and Par6 located to trophoblast cells expressing ZO-1. Together, our data indicate that Par6 negatively regulates trophoblast fusion via its roles on tight junctions and cytoskeleton dynamics and provide novel insight into the contribution of this polarity marker in altered trophoblast cell fusion typical of preeclampsia.
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15
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Dunk CE, Gellhaus A, Drewlo S, Baczyk D, Pötgens AJG, Winterhager E, Kingdom JCP, Lye SJ. The molecular role of connexin 43 in human trophoblast cell fusion. Biol Reprod 2012; 86:115. [PMID: 22238282 DOI: 10.1095/biolreprod.111.096925] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Connexin expression and gap junctional intercellular communication (GJIC) mediated by connexin 43 (Cx43)/gap junction A1 (GJA1) are required for cytotrophoblast fusion into the syncytium, the outer functional layer of the human placenta. Cx43 also impacts intracellular signaling through protein-protein interactions. The transcription factor GCM1 and its downstream target ERVW-1/SYNCYTIN-1 are key players in trophoblast fusion and exert their actions through the ERVW-1 receptor SLC1A5/ASCT-2/RDR/ATB(0). To investigate the molecular role of the Cx43 protein and its interaction with this fusogenic pathway, we utilized stable Cx43-transfected cell lines established from the choriocarcinoma cell line Jeg3: wild-type Jeg3, alphahCG/Cx43 (constitutive Cx43 expression), JpUHD/Cx43 (doxycyclin-inducible Cx43 expression), or JpUHD/trCx43 (doxycyclin-inducible Cx43 carboxyterminal deleted). We hypothesized that truncation of Cx43 at its C-terminus would inhibit trophoblast fusion and protein interaction with either ERVW-1 or SLC1A5. In the alphahCG/Cx43 and JpUHD/Cx43 lines, stimulation with cAMP caused 1) increase in GJA1 mRNA levels, 2) increase in percentage of fused cells, and 3) downregulation of SLC1A5 expression. Cell fusion was inhibited by GJIC blockade using carbenoxylone. Neither Jeg3, which express low levels of Cx43, nor the JpUHD/trCx43 cell line demonstrated cell fusion or downregulation of SLC1A5. However, GCM1 and ERVW-1 mRNAs were upregulated by cAMP treatment in both Jeg3 and all Cx43 cell lines. Silencing of GCM1 prevented the induction of GJA1 mRNA by forskolin in BeWo choriocarcinoma cells, demonstrating that GCM1 is upstream of Cx43. All cell lines and first-trimester villous explants also demonstrated coimmunoprecipitation of SLC1A5 and phosphorylated Cx43. Importantly, SLC1A5 and Cx43 gap junction plaques colocalized in situ to areas of fusing cytotrophoblast, as demonstrated by the loss of E-cadherin staining in the plasma membrane in first-trimester placenta. We conclude that Cx43-mediated GJIC and SLC1A5 interaction play important functional roles in trophoblast cell fusion.
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Affiliation(s)
- Caroline E Dunk
- Research Centre for Women's and Infants' Health, Samuel Lunenfeld Research Institute, Mount Sinai Hospital, University of Toronto, Toronto, Ontario, Canada.
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16
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Bainbridge SA, Minhas A, Whiteley KJ, Qu D, Sled JG, Kingdom JCP, Adamson SL. Effects of reduced Gcm1 expression on trophoblast morphology, fetoplacental vascularity, and pregnancy outcomes in mice. Hypertension 2012; 59:732-9. [PMID: 22275534 DOI: 10.1161/hypertensionaha.111.183939] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Preeclampsia is a life-threatening disorder characterized by maternal gestational hypertension and proteinuria that results from placental dysfunction. Placental abnormalities include abnormal syncytiotrophoblast and a 50% reduction in placental expression of the transcription factor Gcm1. In mice, homozygous deletion of Gcm1 prevents syncytiotrophoblast differentiation and is embryonic lethal. We used heterozygous Gcm1 mutants (Gcm1(+/-)) to test the hypothesis that hypomorphic expression of placental Gcm1 causes defective syncytiotrophoblast differentiation and maternal and placental phenotypes that resemble preeclampsia. We mated wild-type female mice with Gcm1(+/-) fathers to obtain wild-type mothers carrying ≈50% Gcm1(+/-) conceptuses. Gcm1(+/-) placentas had syncytiotrophoblast abnormalities including reduced gene expression of Gcm1-regulated SynB, elevated expression of sFlt1, a thickened interhemal membrane separating maternal and fetal circulations, and electron microscopic evidence in syncytiotrophoblast of necrosis and impaired maternal-fetal transfer. Fetoplacental vascularity was quantified by histomorphometry and microcomputed tomography imaging. In Gcm1(+/-), it was ≈30% greater than wild-type littermates, whereas placental vascular endothelial growth factor A (Vegfa) expression and fetal and placental weights did not differ. Wild-type mothers carrying Gcm1(+/-) conceptuses developed late gestational hypertension (118±2 versus 109.6±0.7 mm Hg in controls; P<0.05). We next correlated fetoplacental vascularity with placental Gcm1 expression in human control and pathological pregnancies and found that, as in mice, fetoplacental vascularity increased when GCM1 protein expression decreased (R(2)=-0.45; P<0.05). These results support a role for reduced placental Gcm1 expression as a causative factor in defective syncytiotrophoblast differentiation and maternal and placental phenotypes in preeclampsia in humans.
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Oxysterols inhibit differentiation and fusion of term primary trophoblasts by activating liver X receptors. Placenta 2011; 32:183-91. [DOI: 10.1016/j.placenta.2010.12.007] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2010] [Revised: 11/30/2010] [Accepted: 12/07/2010] [Indexed: 11/20/2022]
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Huppertz B, Gauster M. Trophoblast fusion. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2011; 713:81-95. [PMID: 21432015 DOI: 10.1007/978-94-007-0763-4_6] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The villous trophoblast of the human placenta is the epithelial cover of the fetal chorionic villi floating in maternal blood. This epithelial cover is organized in two distinct layers, the multinucleated syncytiotrophoblast directly facing maternal blood and a second layer of mononucleated cytotrophoblasts. During pregnancy single cytotrophoblasts continuously fuse with the overlying syncytiotrophoblast to preserve this end-differentiated layer until delivery. Syncytial fusion continuously supplies the syncytiotrophoblast with compounds of fusing cytotrophoblasts such as proteins, nucleic acids and lipids as well as organelles. At the same time the input of cytotrophoblastic components is counterbalanced by a continuous release of apoptotic material from the syncytiotrophoblast into maternal blood. Fusion is an essential step in maintaining the syncytiotrophoblast. Trophoblast fusion was shown to be dependant on and regulated by multiple factors such as fusion proteins, proteases and cytoskeletal proteins as well as cytokines, hormones and transcription factors. In this chapter we focus on factors that may be involved in the fusion process of trophoblast directly or that may prepare the cytotrophoblast to fuse.
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Affiliation(s)
- Berthold Huppertz
- Institute of Cell Biology, Histology and Embryology, Center for Molecular Medicine, Medical University of Graz, 8010, Graz, Austria.
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Nakaya Y, Shojima T, Yasuda J, Imakawa K, Miyazawa T. Epigenetic regulation on the 5'-proximal CpG island of human porcine endogenous retrovirus subgroup A receptor 2/GPR172B. Microbes Infect 2010; 13:49-57. [PMID: 20951222 DOI: 10.1016/j.micinf.2010.09.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2010] [Revised: 09/27/2010] [Accepted: 09/30/2010] [Indexed: 11/19/2022]
Abstract
Porcine endogenous retroviruses (PERVs) have been considered one of the major risks of xenotransplantation from pigs to humans. PERV-A efficiently utilizes human PERV-A receptor 2 (HuPAR-2)/GPR172B to infect human cells; however, there has been no study on the regulation mechanisms of HuPAR-2/GPR172B expression. In this study, we examined the expression of HuPAR-2/GPR172B from the standpoint of epigenetic regulation and discussed the risks of PERV-A infection in xenotransplantation. Quantitative real-time RT-PCR revealed that HuPAR-2 mRNA was preferentially expressed in placental tissue, whereas it was highly suppressed in BeWo cells (a human choriocarcinoma cell line) and HEK293 cells. A CpG island containing the HuPAR-2 transcription starting site was identified by in silico analysis. The DNA methylation ratio (the relative quantity of methylcytosine to total cytosine) and histone modification (H3K9me3) levels in the CpG island measured by bisulfite genomic sequencing and ChIP assay, respectively, were inversely correlated with the mRNA levels. Both HuPAR-2 mRNA and HuPAR-2 protein were up-regulated in HEK293 cells by inhibiting DNA methylation and histone deacetylation. Additionally, promoter/enhancer activities within the CpG island were suppressed by in vitro DNA methylation. Our results demonstrated that epigenetic modification regulates HuPAR-2 expression.
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Affiliation(s)
- Yuki Nakaya
- Laboratory of Signal Transduction, Department of Cell Biology, Institute for Virus Research, Kyoto University, 53 Shogoin-Kawaharacho, Sakyo-ku, Kyoto, Japan
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Gauster M, Moser G, Orendi K, Huppertz B. Factors involved in regulating trophoblast fusion: potential role in the development of preeclampsia. Placenta 2008; 30 Suppl A:S49-54. [PMID: 19027159 DOI: 10.1016/j.placenta.2008.10.011] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2008] [Revised: 10/16/2008] [Accepted: 10/20/2008] [Indexed: 10/21/2022]
Abstract
In the human placenta, turnover of villous trophoblast involves proliferation, differentiation and fusion of mononucleated cytotrophoblasts with the overlying syncytiotrophoblast. In this way the syncytiotrophoblast is continuously supplied with compounds derived from the fusing cytotrophoblasts. Acquisition of fresh cellular components is balanced by a concomitant release of apoptotic material as syncytial knots from the syncytiotrophoblast to the maternal circulation. In the turnover of villous trophoblast, fusion is an essential step and has been shown to be regulated by multiple factors, such as cytokines, hormones, protein kinases, transcription factors, proteases and membrane proteins. Dysregulation of one or more of these fusion factors entails aberrant fusion of the cytotrophoblast with the syncytiotrophoblast, which adversely affects the maintenance and integrity of the placental barrier. Unbalanced trophoblast fusion and release of apoptotic material into the intervillous space may provoke a massive systemic inflammatory response by the mother and thus lead to preeclampsia.
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Affiliation(s)
- M Gauster
- Institute of Cell Biology, Histology and Embryology, Medical University of Graz, Harrachgasse 21/VII, 8010 Graz, Austria.
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