The Experts below are selected from a list of 13032 Experts worldwide ranked by ideXlab platform
Susan J Fisher - One of the best experts on this subject based on the ideXlab platform.
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polysialic acid enhances the migration and invasion of human Cytotrophoblasts
Glycobiology, 2013Co-Authors: Bethann S Hromatka, Mirhan Kapidzic, Penelope M Drake, Haley Stolp, Gabriel Goldfien, Ie Ming Shih, Susan J FisherAbstract:Polysialic acid (polySia) is a large, cell-surface linear homopolymer composed of α2,8-linked sialic acid residues. Most extensively studied in the nervous system, this unique glycan modulates development by enhancing cell migration and regulating differentiation. PolySia also functions in developing and adult immune systems and is a signature of many cancers. In this study, we demonstrated that human placental trophoblasts, an epithelial lineage, also display this glycan. Cytotrophoblasts and syncytiotrophoblasts expressed polySia in the first trimester and downregulated it during the course of pregnancy. PolySia promoted Cytotrophoblast migration in an explant model of chorionic villous growth. Removal of this glycan also reduced Cytotrophoblast penetration of basement membranes in an in vitro model of invasion. Finally, we showed that polySia was overexpressed in biopsies from patients with gestational trophoblastic diseases, including benign molar pregnancies and malignant choriocarcinomas. These results demonstrated, for the first time, functional roles for polySia during normal human placental development and implicated these unusual oligosaccharides in the unrestrained invasion of trophoblast tumors.
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the placental problem linking abnormal Cytotrophoblast differentiation to the maternal symptoms of preeclampsia
Reproductive Biology and Endocrinology, 2004Co-Authors: Susan J FisherAbstract:The placenta is a remarkable organ. In normal pregnancy its specialized cells (termed Cytotrophoblasts) differentiate into various specialized subpopulations that play pivotal roles in governing fetal growth and development. One Cytotrophoblast subset acquires tumor-like properties that allow the cells to invade the decidua and myometrium, a process that attaches the placenta to the uterus. The same subset also adopts a vascular phenotype that allows these fetal cells to breach and subsequently line uterine blood vessels, a process that channels maternal blood to the rest of the placenta. In the pregnancy complication preeclampsia, which is characterized by the sudden onset of maternal hypertension, proteinuria and edema, Cytotrophoblast invasion is shallow and vascular transformation incomplete. These findings, together with very recent evidence from animal models, suggest that preeclampsia is associated with abnormal placental production of vasculogenic/angiogenic substances that reach the maternal circulation with the potential to produce at least a subset of the clinical signs of this syndrome. The current challenge is to build on this knowledge to design clinically useful tests for predicting, diagnosing and treating this dangerous disorder.
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human cytomegalovirus interleukin 10 downregulates metalloproteinase activity and impairs endothelial cell migration and placental Cytotrophoblast invasiveness in vitro
Journal of Virology, 2004Co-Authors: Takako Yamamototabata, Susan J Fisher, Susan Mcdonagh, Hsinti Chang, Lenore PereiraAbstract:At the uterine-placental interface, fetal Cytotrophoblasts invade the decidua, breach maternal blood vessels, and form heterotypic contacts with uterine microvascular endothelial cells. In early gestation, differentiating- invading Cytotrophoblasts produce high levels of matrix metalloproteinase 9 (MMP-9), which degrades the extracellular matrix and increases the invasion depth. By midgestation, when invasion is complete, MMP levels are reduced. Cytotrophoblasts also produce human interleukin-10 (hIL-10), a pleiotropic cytokine that modulates immune responses, helping to protect the fetal hemiallograft from rejection. Human cytomegalovirus (CMV) is often detected at the uterine-placental interface. CMV infection impairs Cytotrophoblast differentiation and invasion, altering the expression of the cell adhesion and immune molecules. Here we report that infection with a clinical CMV strain, VR1814, but not a laboratory strain, AD169, downregulates MMP activity in uterine microvascular endothelial cells and differentiating-invading Cytotrophoblasts. Infected Cytotrophoblasts expressed CMV IL-10 (cmvIL-10) mRNA and secreted the viral cytokine, which upregulated hIL-10. Functional analyses showed that cmvIL-10 treatment impaired migration in endothelial cell wounding assays and Cytotrophoblast invasion of Matrigel in vitro. Comparable changes occurred in cells that were exposed to recombinant hIL-10 or cmvIL-10. Our results show that cmvIL-10 decreases MMP activity and dysregulates the cell-cell and/or cell-matrix interactions of infected Cytotrophoblasts and endothelial cells. Reduced MMP activity early in placental development could impair Cytotrophoblast remodeling of the uterine vasculature and eventually restrict fetal growth in affected pregnancies.
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the human placenta remodels the uterus by using a combination of molecules that govern vasculogenesis or leukocyte extravasation
Annals of the New York Academy of Sciences, 2003Co-Authors: Yan Zhou, Olga Genbacev, Susan J FisherAbstract:Abstract: After fertilization, the next major hurdle for human reproduction is trophoblast differentiation, which is required for implantation, followed in lockstep by rapid assembly of these embryonic cells into a functional placenta. During this process, Cytotrophoblast stem cells invade the uterus, anchoring the conceptus to the mother and establishing blood flow to the placenta. Cytotrophoblast invasion is actually a differentiation process that yields cells with many unusual attributes, that is, their tumor-like ability to invade the uterus and engraft maternal blood vessels. We discovered that once Cytotrophoblasts commit to invasion they turn on expression of adhesion receptors characteristic of endothelium. They also begin to express and activate matrix metalloproteinase-9. Together, these phenotypic changes facilitate invasion while enabling Cytotrophoblasts to present an endothelium-like surface to maternal blood. Currently, we are trying to understand the factors that play a role in Cytotrophoblast differentiation/invasion. In keeping with the vascular characteristics that differentiated Cytotrophoblasts assume, our recent data suggest that the key regulators include an unusual subset of vascular endothelial growth factor family members that play important roles in conventional vasculogenesis/angiogenesis. Surprisingly, we also discovered that these cells express functional l-selectin, which mediates neutrophil rolling and tethering, under shear stress, on inflamed endothelium. Trophoblast l-selectin likely interacts with carbohydrate selectin ligands that are upregulated on uterine glandular epithelium during the window of receptivity. Together, these data suggest that differentiating Cytotrophoblasts have co-opted portions not only of vasculogenesis, but also of the process that facilitates leukocyte emigration from the blood into tissues, additional evidence of these cells' amazing plasticity.
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vascular endothelial growth factor ligands and receptors that regulate human Cytotrophoblast survival are dysregulated in severe preeclampsia and hemolysis elevated liver enzymes and low platelets syndrome
American Journal of Pathology, 2002Co-Authors: Yan Zhou, Michael T Mcmaster, Mary Janatpour, Jean Perry, Terhi Karpanen, Kari Alitalo, Caroline H Damsky, Susan J FisherAbstract:Human placental development combines elements of tumorigenesis and vasculogenesis. The organ's specialized epithelial cells, termed Cytotrophoblasts, invade the uterus where they reside in the interstitial compartment. They also line uterine arteries and veins. During invasion, ectodermally derived Cytotrophoblasts undergo pseudovasculogenesis, switching their adhesion molecule repertoire to mimic that of vascular cells. Failures in this transformation accompany the pregnancy complication preeclampsia. Here, we used a combination of in situ and in vitro analyses to characterize the cell's expression of vascular endothelial growth factor (VEGF) family ligands and receptors, key regulators of conventional vasculogenesis and angiogenesis. Cytotrophoblast differentiation and invasion during the first and second trimesters of pregnancy were associated with down-regulation of VEGF receptor (VEGFR)-2. Invasive Cytotrophoblasts in early gestation expressed VEGF-A, VEGF-C, placental growth factor (PlGF), VEGFR-1, and VEGFR-3 and, at term, VEGF-A, PlGF, and VEGFR-1. In vitro the cells incorporated VEGF-A into the surrounding extracellular matrix; PlGF was secreted. We also found that Cytotrophoblasts responded to the VEGF ligands they produced. Blocking ligand binding significantly decreased their expression of integrin α1, an adhesion molecule highly expressed by endovascular Cytotrophoblasts, and increased apoptosis. In severe preeclampsia and hemolysis, elevated liver enzymes, and low platelets syndrome, immunolocalization on tissue sections showed that Cytotrophoblast VEGF-A and VEGFR-1 staining decreased; staining for PlGF was unaffected. Cytotrophoblast secretion of the soluble form of VEGFR-1 in vitro also increased. Together, the results of this study showed that VEGF family members regulate Cytotrophoblast survival and that expression of a subset of family members is dysregulated in severe forms of preeclampsia.
Yan Zhou - One of the best experts on this subject based on the ideXlab platform.
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Cytotrophoblast induction of arterial apoptosis and lymphangiogenesis in an in vivo model of human placentation
Journal of Clinical Investigation, 2006Co-Authors: Kristy Redhorse, Yan Zhou, A. Schanz, Jose Rivera, Virginia D Winn, Mirhan Kapidzic, Emin Maltepe, Kelly M Okazaki, Ronit Kochman, Linda C GiudiceAbstract:We studied the vascular effects of invasive human Cytotrophoblasts in vivo by transplanting placental villi to the fifth mammary fat pads or beneath the kidney capsules of Scid mice. Over 3 weeks, robust Cytotrophoblast invasion was observed in both locations. The architecture of the mammary fat pad allowed for detailed analysis of the cells' interactions with resident murine blood vessels, which revealed specific induction of apoptosis in the endothelial cells and smooth muscle walls of the arterioles. This finding, and confirmation of the results in an in vitro coculture model, suggests that a parallel process is important for enabling Cytotrophoblast endovascular invasion during human pregnancy. Cytotrophoblast invasion of the kidney parenchyma was accompanied by a robust lymphangiogenic response, while in vitro, the cells stimulated lymphatic endothelial cell migration via the actions of VEGF family members, FGF, and TNF-alpha. Immunolocalization analyses revealed that human pregnancy is associated with lymphangiogenesis in the decidua since lymphatic vessels were not a prominent feature of the nonpregnant endometrium. Thus, the placenta triggers the development of a decidual lymphatic circulation, which we theorize plays an important role in maintaining fluid balance during pregnancy, with possible implications for maternal-fetal immune cell trafficking.
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the human placenta remodels the uterus by using a combination of molecules that govern vasculogenesis or leukocyte extravasation
Annals of the New York Academy of Sciences, 2003Co-Authors: Yan Zhou, Olga Genbacev, Susan J FisherAbstract:Abstract: After fertilization, the next major hurdle for human reproduction is trophoblast differentiation, which is required for implantation, followed in lockstep by rapid assembly of these embryonic cells into a functional placenta. During this process, Cytotrophoblast stem cells invade the uterus, anchoring the conceptus to the mother and establishing blood flow to the placenta. Cytotrophoblast invasion is actually a differentiation process that yields cells with many unusual attributes, that is, their tumor-like ability to invade the uterus and engraft maternal blood vessels. We discovered that once Cytotrophoblasts commit to invasion they turn on expression of adhesion receptors characteristic of endothelium. They also begin to express and activate matrix metalloproteinase-9. Together, these phenotypic changes facilitate invasion while enabling Cytotrophoblasts to present an endothelium-like surface to maternal blood. Currently, we are trying to understand the factors that play a role in Cytotrophoblast differentiation/invasion. In keeping with the vascular characteristics that differentiated Cytotrophoblasts assume, our recent data suggest that the key regulators include an unusual subset of vascular endothelial growth factor family members that play important roles in conventional vasculogenesis/angiogenesis. Surprisingly, we also discovered that these cells express functional l-selectin, which mediates neutrophil rolling and tethering, under shear stress, on inflamed endothelium. Trophoblast l-selectin likely interacts with carbohydrate selectin ligands that are upregulated on uterine glandular epithelium during the window of receptivity. Together, these data suggest that differentiating Cytotrophoblasts have co-opted portions not only of vasculogenesis, but also of the process that facilitates leukocyte emigration from the blood into tissues, additional evidence of these cells' amazing plasticity.
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vascular endothelial growth factor ligands and receptors that regulate human Cytotrophoblast survival are dysregulated in severe preeclampsia and hemolysis elevated liver enzymes and low platelets syndrome
American Journal of Pathology, 2002Co-Authors: Yan Zhou, Michael T Mcmaster, Mary Janatpour, Jean Perry, Terhi Karpanen, Kari Alitalo, Caroline H Damsky, Susan J FisherAbstract:Human placental development combines elements of tumorigenesis and vasculogenesis. The organ's specialized epithelial cells, termed Cytotrophoblasts, invade the uterus where they reside in the interstitial compartment. They also line uterine arteries and veins. During invasion, ectodermally derived Cytotrophoblasts undergo pseudovasculogenesis, switching their adhesion molecule repertoire to mimic that of vascular cells. Failures in this transformation accompany the pregnancy complication preeclampsia. Here, we used a combination of in situ and in vitro analyses to characterize the cell's expression of vascular endothelial growth factor (VEGF) family ligands and receptors, key regulators of conventional vasculogenesis and angiogenesis. Cytotrophoblast differentiation and invasion during the first and second trimesters of pregnancy were associated with down-regulation of VEGF receptor (VEGFR)-2. Invasive Cytotrophoblasts in early gestation expressed VEGF-A, VEGF-C, placental growth factor (PlGF), VEGFR-1, and VEGFR-3 and, at term, VEGF-A, PlGF, and VEGFR-1. In vitro the cells incorporated VEGF-A into the surrounding extracellular matrix; PlGF was secreted. We also found that Cytotrophoblasts responded to the VEGF ligands they produced. Blocking ligand binding significantly decreased their expression of integrin α1, an adhesion molecule highly expressed by endovascular Cytotrophoblasts, and increased apoptosis. In severe preeclampsia and hemolysis, elevated liver enzymes, and low platelets syndrome, immunolocalization on tissue sections showed that Cytotrophoblast VEGF-A and VEGFR-1 staining decreased; staining for PlGF was unaffected. Cytotrophoblast secretion of the soluble form of VEGFR-1 in vitro also increased. Together, the results of this study showed that VEGF family members regulate Cytotrophoblast survival and that expression of a subset of family members is dysregulated in severe forms of preeclampsia.
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vascular endothelial growth factor ligands and receptors that regulate human Cytotrophoblast survival are dysregulated in severe preeclampsia and hemolysis elevated liver enzymes and low platelets syndrome
American Journal of Pathology, 2002Co-Authors: Yan Zhou, Michael T Mcmaster, Mary Janatpour, Jean Perry, Terhi Karpanen, Kari Alitalo, Caroline H Damsky, Kirstin Woo, Susan J FisherAbstract:Human placental development combines elements of tumorigenesis and vasculogenesis. The organ's specialized epithelial cells, termed Cytotrophoblasts, invade the uterus where they reside in the interstitial compartment. They also line uterine arteries and veins. During invasion, ectodermally derived Cytotrophoblasts undergo pseudovasculogenesis, switching their adhesion molecule repertoire to mimic that of vascular cells. Failures in this transformation accompany the pregnancy complication preeclampsia. Here, we used a combination of in situ and in vitro analyses to characterize the cell's expression of vascular endothelial growth factor (VEGF) family ligands and receptors, key regulators of conventional vasculogenesis and angiogenesis. Cytotrophoblast differentiation and invasion during the first and second trimesters of pregnancy were associated with down-regulation of VEGF receptor (VEGFR)-2. Invasive Cytotrophoblasts in early gestation expressed VEGF-A, VEGF-C, placental growth factor (PlGF), VEGFR-1, and VEGFR-3 and, at term, VEGF-A, PlGF, and VEGFR-1. In vitro the cells incorporated VEGF-A into the surrounding extracellular matrix; PlGF was secreted. We also found that Cytotrophoblasts responded to the VEGF ligands they produced. Blocking ligand binding significantly decreased their expression of integrin α1, an adhesion molecule highly expressed by endovascular Cytotrophoblasts, and increased apoptosis. In severe preeclampsia and hemolysis, elevated liver enzymes, and low platelets syndrome, immunolocalization on tissue sections showed that Cytotrophoblast VEGF-A and VEGFR-1 staining decreased; staining for PlGF was unaffected. Cytotrophoblast secretion of the soluble form of VEGFR-1 in vitro also increased. Together, the results of this study showed that VEGF family members regulate Cytotrophoblast survival and that expression of a subset of family members is dysregulated in severe forms of preeclampsia.
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Id-2 regulates critical aspects of human Cytotrophoblast differentiation, invasion and migration
Development (Cambridge England), 2000Co-Authors: Mary Janatpour, Yan Zhou, Michael T Mcmaster, Olga Genbacev, Jian-yun Dong, James C. Cross, Mark A. Israel, Susan J FisherAbstract:During early human placental development, the conceptus attaches itself to the uterus through Cytotrophoblast invasion. Invasive Cytotrophoblast cells differentiate from precursor villous Cytotrophoblasts, but the essential regulating factors in this process are unknown. Basic helix-loop-helix (bHLH) transcription factor dimers are essential regulators of mouse trophoblast development. We therefore examined the importance of this family of factors in the human placenta. In many cell lineages, bHLH factors are sequestered by members of the Id family, HLH proteins that lack the basic DNA binding domain (Inhibitor of DNA binding proteins (Id-1 to Id-4)). During differentiation of some tissues, Id expression declines, allowing bHLH factors to dimerize, bind DNA and trans-activate lineage-specific genes. To begin to study the role of bHLH transcription factors in human placental development, we first characterized Id expression in Cytotrophoblast cells. The cells expressed Id-3 constitutively; Id-2 was downregulated, at the mRNA and protein levels, as the cells differentiated in culture and in situ, respectively. In cases when Cytotrophoblast differentiation was compromised (in placentas from women with preeclampsia, or in cells grown under hypoxic conditions in culture), Id-2 expression was maintained. To assess the functional relevance of these correlations, we used an adenovirus vector to maintain Id-2 protein expression in cultured Cytotrophoblasts. Compared to control (lacZ-expressing) cells, Cytotrophoblasts transduced to constitutively express Id-2 retained characteristics of undifferentiated cells: (alpha)1 integrin expression was low and cyclin B expression was retained. Furthermore, invasion through Matrigel was partially inhibited and migration was strikingly enhanced in Id-2-expressing cells. These results suggest that Id-2 and the bHLH factors that it partners play important roles in human Cytotrophoblast development.
Mary Janatpour - One of the best experts on this subject based on the ideXlab platform.
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vascular endothelial growth factor ligands and receptors that regulate human Cytotrophoblast survival are dysregulated in severe preeclampsia and hemolysis elevated liver enzymes and low platelets syndrome
American Journal of Pathology, 2002Co-Authors: Yan Zhou, Michael T Mcmaster, Mary Janatpour, Jean Perry, Terhi Karpanen, Kari Alitalo, Caroline H Damsky, Susan J FisherAbstract:Human placental development combines elements of tumorigenesis and vasculogenesis. The organ's specialized epithelial cells, termed Cytotrophoblasts, invade the uterus where they reside in the interstitial compartment. They also line uterine arteries and veins. During invasion, ectodermally derived Cytotrophoblasts undergo pseudovasculogenesis, switching their adhesion molecule repertoire to mimic that of vascular cells. Failures in this transformation accompany the pregnancy complication preeclampsia. Here, we used a combination of in situ and in vitro analyses to characterize the cell's expression of vascular endothelial growth factor (VEGF) family ligands and receptors, key regulators of conventional vasculogenesis and angiogenesis. Cytotrophoblast differentiation and invasion during the first and second trimesters of pregnancy were associated with down-regulation of VEGF receptor (VEGFR)-2. Invasive Cytotrophoblasts in early gestation expressed VEGF-A, VEGF-C, placental growth factor (PlGF), VEGFR-1, and VEGFR-3 and, at term, VEGF-A, PlGF, and VEGFR-1. In vitro the cells incorporated VEGF-A into the surrounding extracellular matrix; PlGF was secreted. We also found that Cytotrophoblasts responded to the VEGF ligands they produced. Blocking ligand binding significantly decreased their expression of integrin α1, an adhesion molecule highly expressed by endovascular Cytotrophoblasts, and increased apoptosis. In severe preeclampsia and hemolysis, elevated liver enzymes, and low platelets syndrome, immunolocalization on tissue sections showed that Cytotrophoblast VEGF-A and VEGFR-1 staining decreased; staining for PlGF was unaffected. Cytotrophoblast secretion of the soluble form of VEGFR-1 in vitro also increased. Together, the results of this study showed that VEGF family members regulate Cytotrophoblast survival and that expression of a subset of family members is dysregulated in severe forms of preeclampsia.
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vascular endothelial growth factor ligands and receptors that regulate human Cytotrophoblast survival are dysregulated in severe preeclampsia and hemolysis elevated liver enzymes and low platelets syndrome
American Journal of Pathology, 2002Co-Authors: Yan Zhou, Michael T Mcmaster, Mary Janatpour, Jean Perry, Terhi Karpanen, Kari Alitalo, Caroline H Damsky, Kirstin Woo, Susan J FisherAbstract:Human placental development combines elements of tumorigenesis and vasculogenesis. The organ's specialized epithelial cells, termed Cytotrophoblasts, invade the uterus where they reside in the interstitial compartment. They also line uterine arteries and veins. During invasion, ectodermally derived Cytotrophoblasts undergo pseudovasculogenesis, switching their adhesion molecule repertoire to mimic that of vascular cells. Failures in this transformation accompany the pregnancy complication preeclampsia. Here, we used a combination of in situ and in vitro analyses to characterize the cell's expression of vascular endothelial growth factor (VEGF) family ligands and receptors, key regulators of conventional vasculogenesis and angiogenesis. Cytotrophoblast differentiation and invasion during the first and second trimesters of pregnancy were associated with down-regulation of VEGF receptor (VEGFR)-2. Invasive Cytotrophoblasts in early gestation expressed VEGF-A, VEGF-C, placental growth factor (PlGF), VEGFR-1, and VEGFR-3 and, at term, VEGF-A, PlGF, and VEGFR-1. In vitro the cells incorporated VEGF-A into the surrounding extracellular matrix; PlGF was secreted. We also found that Cytotrophoblasts responded to the VEGF ligands they produced. Blocking ligand binding significantly decreased their expression of integrin α1, an adhesion molecule highly expressed by endovascular Cytotrophoblasts, and increased apoptosis. In severe preeclampsia and hemolysis, elevated liver enzymes, and low platelets syndrome, immunolocalization on tissue sections showed that Cytotrophoblast VEGF-A and VEGFR-1 staining decreased; staining for PlGF was unaffected. Cytotrophoblast secretion of the soluble form of VEGFR-1 in vitro also increased. Together, the results of this study showed that VEGF family members regulate Cytotrophoblast survival and that expression of a subset of family members is dysregulated in severe forms of preeclampsia.
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Id-2 regulates critical aspects of human Cytotrophoblast differentiation, invasion and migration
Development (Cambridge England), 2000Co-Authors: Mary Janatpour, Yan Zhou, Michael T Mcmaster, Olga Genbacev, Jian-yun Dong, James C. Cross, Mark A. Israel, Susan J FisherAbstract:During early human placental development, the conceptus attaches itself to the uterus through Cytotrophoblast invasion. Invasive Cytotrophoblast cells differentiate from precursor villous Cytotrophoblasts, but the essential regulating factors in this process are unknown. Basic helix-loop-helix (bHLH) transcription factor dimers are essential regulators of mouse trophoblast development. We therefore examined the importance of this family of factors in the human placenta. In many cell lineages, bHLH factors are sequestered by members of the Id family, HLH proteins that lack the basic DNA binding domain (Inhibitor of DNA binding proteins (Id-1 to Id-4)). During differentiation of some tissues, Id expression declines, allowing bHLH factors to dimerize, bind DNA and trans-activate lineage-specific genes. To begin to study the role of bHLH transcription factors in human placental development, we first characterized Id expression in Cytotrophoblast cells. The cells expressed Id-3 constitutively; Id-2 was downregulated, at the mRNA and protein levels, as the cells differentiated in culture and in situ, respectively. In cases when Cytotrophoblast differentiation was compromised (in placentas from women with preeclampsia, or in cells grown under hypoxic conditions in culture), Id-2 expression was maintained. To assess the functional relevance of these correlations, we used an adenovirus vector to maintain Id-2 protein expression in cultured Cytotrophoblasts. Compared to control (lacZ-expressing) cells, Cytotrophoblasts transduced to constitutively express Id-2 retained characteristics of undifferentiated cells: (alpha)1 integrin expression was low and cyclin B expression was retained. Furthermore, invasion through Matrigel was partially inhibited and migration was strikingly enhanced in Id-2-expressing cells. These results suggest that Id-2 and the bHLH factors that it partners play important roles in human Cytotrophoblast development.
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a repertoire of differentially expressed transcription factors that offers insight into mechanisms of human Cytotrophoblast differentiation
Developmental Genetics, 1999Co-Authors: Mary Janatpour, Jian-yun Dong, James C. Cross, Mark A. Israel, Manuel F Utset, Janet Rossant, Susan J FisherAbstract:During human placental development, specialized cells allocated to the extraembryonic lineage (Cytotrophoblasts) invade the uterus, anchoring the conceptus to the decidua and tapping a supply of maternal blood. This unusual behavior requires Cytotrophoblasts to assume highly specialized characteristics; some are commonly associated with tumor cells, while others are typical of endothelia. Here we investigated the transcriptional mechanisms that control Cytotrophoblast differentiation/invasion. Specifically, we examined the cells' expression of a number of transcription factors, at the RNA level, as they differentiated along the invasive pathway in vitro. Since basic helix-loop-helix (bHLH) proteins play important roles in murine trophoblast differentiation, we first examined their expression by Cytotrophoblasts. As in murine placental development, expression of the human homologue of Mash-2 was confined to progenitor cells. But expression of Hand-1, which promotes differentiation of murine trophoblast giant cells, was not detected. We also found that Cytotrophoblasts upregulated the expression of bHLH/PAS factors that function in adaptive responses to hypoxia, including hEPAS-1, which is expressed primarily in endothelial cells. Quite unexpectedly, we discovered that Cytotrophoblasts express high levels of mRNA encoding the human homologue of the Drosophila neuronal fate gene, glial cells missing-1 (gcm-1). We also found evidence of crosstalk between the bHLH and GCM-1 regulatory networks. Together, these results offer insights into the transcriptional mechanisms that govern Cytotrophoblast differentiation/invasion. Interestingly, these mechanisms suggest analogies with those that govern differentiation of murine stem cells allocated to both the intra- and extraembryonic lineages. Dev. Genet. 25:146–157, 1999. © 1999 Wiley-Liss, Inc.
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a repertoire of differentially expressed transcription factors that offers insight into mechanisms of human Cytotrophoblast differentiation
Developmental Genetics, 1999Co-Authors: Mary Janatpour, Jian-yun Dong, James C. Cross, Mark A. Israel, Manuel F Utset, Janet Rossant, Susan J FisherAbstract:During human placental development, specialized cells allocated to the extraembryonic lineage (Cytotrophoblasts) invade the uterus, anchoring the conceptus to the decidua and tapping a supply of maternal blood. This unusual behavior requires Cytotrophoblasts to assume highly specialized characteristics; some are commonly associated with tumor cells, while others are typical of endothelia. Here we investigated the transcriptional mechanisms that control Cytotrophoblast differentiation/invasion. Specifically, we examined the cells' expression of a number of transcription factors, at the RNA level, as they differentiated along the invasive pathway in vitro. Since basic helix-loop-helix (bHLH) proteins play important roles in murine trophoblast differentiation, we first examined their expression by Cytotrophoblasts. As in murine placental development, expression of the human homologue of Mash-2 was confined to progenitor cells. But expression of Hand-1, which promotes differentiation of murine trophoblast giant cells, was not detected. We also found that Cytotrophoblasts upregulated the expression of bHLH/PAS factors that function in adaptive responses to hypoxia, including hEPAS-1, which is expressed primarily in endothelial cells. Quite unexpectedly, we discovered that Cytotrophoblasts express high levels of mRNA encoding the human homologue of the Drosophila neuronal fate gene, glial cells missing-1 (gcm-1). We also found evidence of crosstalk between the bHLH and GCM-1 regulatory networks. Together, these results offer insights into the transcriptional mechanisms that govern Cytotrophoblast differentiation/invasion. Interestingly, these mechanisms suggest analogies with those that govern differentiation of murine stem cells allocated to both the intra- and extraembryonic lineages.
Michael T Mcmaster - One of the best experts on this subject based on the ideXlab platform.
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vascular endothelial growth factor ligands and receptors that regulate human Cytotrophoblast survival are dysregulated in severe preeclampsia and hemolysis elevated liver enzymes and low platelets syndrome
American Journal of Pathology, 2002Co-Authors: Yan Zhou, Michael T Mcmaster, Mary Janatpour, Jean Perry, Terhi Karpanen, Kari Alitalo, Caroline H Damsky, Susan J FisherAbstract:Human placental development combines elements of tumorigenesis and vasculogenesis. The organ's specialized epithelial cells, termed Cytotrophoblasts, invade the uterus where they reside in the interstitial compartment. They also line uterine arteries and veins. During invasion, ectodermally derived Cytotrophoblasts undergo pseudovasculogenesis, switching their adhesion molecule repertoire to mimic that of vascular cells. Failures in this transformation accompany the pregnancy complication preeclampsia. Here, we used a combination of in situ and in vitro analyses to characterize the cell's expression of vascular endothelial growth factor (VEGF) family ligands and receptors, key regulators of conventional vasculogenesis and angiogenesis. Cytotrophoblast differentiation and invasion during the first and second trimesters of pregnancy were associated with down-regulation of VEGF receptor (VEGFR)-2. Invasive Cytotrophoblasts in early gestation expressed VEGF-A, VEGF-C, placental growth factor (PlGF), VEGFR-1, and VEGFR-3 and, at term, VEGF-A, PlGF, and VEGFR-1. In vitro the cells incorporated VEGF-A into the surrounding extracellular matrix; PlGF was secreted. We also found that Cytotrophoblasts responded to the VEGF ligands they produced. Blocking ligand binding significantly decreased their expression of integrin α1, an adhesion molecule highly expressed by endovascular Cytotrophoblasts, and increased apoptosis. In severe preeclampsia and hemolysis, elevated liver enzymes, and low platelets syndrome, immunolocalization on tissue sections showed that Cytotrophoblast VEGF-A and VEGFR-1 staining decreased; staining for PlGF was unaffected. Cytotrophoblast secretion of the soluble form of VEGFR-1 in vitro also increased. Together, the results of this study showed that VEGF family members regulate Cytotrophoblast survival and that expression of a subset of family members is dysregulated in severe forms of preeclampsia.
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vascular endothelial growth factor ligands and receptors that regulate human Cytotrophoblast survival are dysregulated in severe preeclampsia and hemolysis elevated liver enzymes and low platelets syndrome
American Journal of Pathology, 2002Co-Authors: Yan Zhou, Michael T Mcmaster, Mary Janatpour, Jean Perry, Terhi Karpanen, Kari Alitalo, Caroline H Damsky, Kirstin Woo, Susan J FisherAbstract:Human placental development combines elements of tumorigenesis and vasculogenesis. The organ's specialized epithelial cells, termed Cytotrophoblasts, invade the uterus where they reside in the interstitial compartment. They also line uterine arteries and veins. During invasion, ectodermally derived Cytotrophoblasts undergo pseudovasculogenesis, switching their adhesion molecule repertoire to mimic that of vascular cells. Failures in this transformation accompany the pregnancy complication preeclampsia. Here, we used a combination of in situ and in vitro analyses to characterize the cell's expression of vascular endothelial growth factor (VEGF) family ligands and receptors, key regulators of conventional vasculogenesis and angiogenesis. Cytotrophoblast differentiation and invasion during the first and second trimesters of pregnancy were associated with down-regulation of VEGF receptor (VEGFR)-2. Invasive Cytotrophoblasts in early gestation expressed VEGF-A, VEGF-C, placental growth factor (PlGF), VEGFR-1, and VEGFR-3 and, at term, VEGF-A, PlGF, and VEGFR-1. In vitro the cells incorporated VEGF-A into the surrounding extracellular matrix; PlGF was secreted. We also found that Cytotrophoblasts responded to the VEGF ligands they produced. Blocking ligand binding significantly decreased their expression of integrin α1, an adhesion molecule highly expressed by endovascular Cytotrophoblasts, and increased apoptosis. In severe preeclampsia and hemolysis, elevated liver enzymes, and low platelets syndrome, immunolocalization on tissue sections showed that Cytotrophoblast VEGF-A and VEGFR-1 staining decreased; staining for PlGF was unaffected. Cytotrophoblast secretion of the soluble form of VEGFR-1 in vitro also increased. Together, the results of this study showed that VEGF family members regulate Cytotrophoblast survival and that expression of a subset of family members is dysregulated in severe forms of preeclampsia.
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concordant in situ and in vitro data show that maternal cigarette smoking negatively regulates placental Cytotrophoblast passage through the cell cycle
Reproductive Toxicology, 2000Co-Authors: Olga Genbacev, Michael T Mcmaster, Jelena Lazic, Slavin Nedeljkovic, Milos Cvetkovic, Rebecca Joslin, Susan J FisherAbstract:Maternal cigarette smoking is associated with fetal growth restriction and other pregnancy complications. To investigate possible mechanisms involving the placenta, we studied the morphology of first trimester chorionic villi from mothers who smoked. In mothers who smoked > 20 cigarettes/day, floating villi showed focal defects including an absence of Cytotrophoblast stem cells and an abnormal thinning of the syncytium. Anchoring villi displayed a striking increase in the number of Cytotrophoblast columns that failed to reach the uterus or degenerated in the intervillous space. Many samples showed a significant reduction in the number of anchoring villi. Also, the number of Ki67-positive Cytotrophoblasts was dramatically decreased, indicating that fewer cells were in S phase of the mitotic cycle. Together, these results suggested premature depletion of the Cytotrophoblast stem cell population. To test this hypothesis, we exposed anchoring villi from nonsmokers to nicotine in vitro and analyzed the effects on Cytotrophoblast passage through the cell cycle. Nicotine (0.23 to 6.0 μM) negatively affected the expression of a number of cell cycle regulators/markers and BrdU incorporation, without discernable effects on apoptosis. These results link abnormal placental development secondary to maternal cigarette smoking to a substantial decrease in the mitotic potential of Cytotrophoblasts.
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Id-2 regulates critical aspects of human Cytotrophoblast differentiation, invasion and migration
Development (Cambridge England), 2000Co-Authors: Mary Janatpour, Yan Zhou, Michael T Mcmaster, Olga Genbacev, Jian-yun Dong, James C. Cross, Mark A. Israel, Susan J FisherAbstract:During early human placental development, the conceptus attaches itself to the uterus through Cytotrophoblast invasion. Invasive Cytotrophoblast cells differentiate from precursor villous Cytotrophoblasts, but the essential regulating factors in this process are unknown. Basic helix-loop-helix (bHLH) transcription factor dimers are essential regulators of mouse trophoblast development. We therefore examined the importance of this family of factors in the human placenta. In many cell lineages, bHLH factors are sequestered by members of the Id family, HLH proteins that lack the basic DNA binding domain (Inhibitor of DNA binding proteins (Id-1 to Id-4)). During differentiation of some tissues, Id expression declines, allowing bHLH factors to dimerize, bind DNA and trans-activate lineage-specific genes. To begin to study the role of bHLH transcription factors in human placental development, we first characterized Id expression in Cytotrophoblast cells. The cells expressed Id-3 constitutively; Id-2 was downregulated, at the mRNA and protein levels, as the cells differentiated in culture and in situ, respectively. In cases when Cytotrophoblast differentiation was compromised (in placentas from women with preeclampsia, or in cells grown under hypoxic conditions in culture), Id-2 expression was maintained. To assess the functional relevance of these correlations, we used an adenovirus vector to maintain Id-2 protein expression in cultured Cytotrophoblasts. Compared to control (lacZ-expressing) cells, Cytotrophoblasts transduced to constitutively express Id-2 retained characteristics of undifferentiated cells: (alpha)1 integrin expression was low and cyclin B expression was retained. Furthermore, invasion through Matrigel was partially inhibited and migration was strikingly enhanced in Id-2-expressing cells. These results suggest that Id-2 and the bHLH factors that it partners play important roles in human Cytotrophoblast development.
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human Cytotrophoblast differentiation invasion is abnormal in pre eclampsia
American Journal of Pathology, 1997Co-Authors: Yan Zhou, Michael T Mcmaster, Mary Janatpour, Kathryn E. Bass, Kee-hak Lim, S. H. Chun, Susan J FisherAbstract:During human placental development, Cytotrophoblast stem cells differentiate and invade the uterus. Simultaneously, the cells modulate their expression of several classes of stage-specific antigens that mark transitions in the differentiation process and play a role in either uterine invasion (integrin cell-extracellular matrix receptors and matrix metalloproteinase-9) or immune interactions (HLA-G). The pregnancy disease pre-eclampsia is associated with shallow Cytotrophoblast invasion. Previously we showed, by immunofluorescence localization on placental tissue, that in pre-eclampsia invasive Cytotrophoblasts fail to properly modulate their integrin repertoire. This finding suggests possible abnormalities in the differentiation pathway that leads to uterine invasion. Here we used a culture system that supports this differentiation process to compare the differentiative and invasive potential of Cytotrophoblasts obtained from control (n = 8, 22 to 38 weeks) and pre-eclamptic (n = 9, 24 to 38 weeks) placentas. In culture, the cells from pre-eclamptic placentas failed to properly modulate alpha1 integrin and matrix metalloproteinase-9 expression at the protein and mRNA levels. Their invasive potential was also greatly reduced. Likewise, the cells failed to up-regulate HLA-G protein and mRNA expression. These results suggest that defective Cytotrophoblast differentiation/invasion can have significant consequences to the outcome of human pregnancy (ie, development of pre-eclampsia) and that, by the time delivery becomes necessary, the defect is not reversed by removing the cells from the maternal environment.
Caroline H Damsky - One of the best experts on this subject based on the ideXlab platform.
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vascular endothelial growth factor ligands and receptors that regulate human Cytotrophoblast survival are dysregulated in severe preeclampsia and hemolysis elevated liver enzymes and low platelets syndrome
American Journal of Pathology, 2002Co-Authors: Yan Zhou, Michael T Mcmaster, Mary Janatpour, Jean Perry, Terhi Karpanen, Kari Alitalo, Caroline H Damsky, Susan J FisherAbstract:Human placental development combines elements of tumorigenesis and vasculogenesis. The organ's specialized epithelial cells, termed Cytotrophoblasts, invade the uterus where they reside in the interstitial compartment. They also line uterine arteries and veins. During invasion, ectodermally derived Cytotrophoblasts undergo pseudovasculogenesis, switching their adhesion molecule repertoire to mimic that of vascular cells. Failures in this transformation accompany the pregnancy complication preeclampsia. Here, we used a combination of in situ and in vitro analyses to characterize the cell's expression of vascular endothelial growth factor (VEGF) family ligands and receptors, key regulators of conventional vasculogenesis and angiogenesis. Cytotrophoblast differentiation and invasion during the first and second trimesters of pregnancy were associated with down-regulation of VEGF receptor (VEGFR)-2. Invasive Cytotrophoblasts in early gestation expressed VEGF-A, VEGF-C, placental growth factor (PlGF), VEGFR-1, and VEGFR-3 and, at term, VEGF-A, PlGF, and VEGFR-1. In vitro the cells incorporated VEGF-A into the surrounding extracellular matrix; PlGF was secreted. We also found that Cytotrophoblasts responded to the VEGF ligands they produced. Blocking ligand binding significantly decreased their expression of integrin α1, an adhesion molecule highly expressed by endovascular Cytotrophoblasts, and increased apoptosis. In severe preeclampsia and hemolysis, elevated liver enzymes, and low platelets syndrome, immunolocalization on tissue sections showed that Cytotrophoblast VEGF-A and VEGFR-1 staining decreased; staining for PlGF was unaffected. Cytotrophoblast secretion of the soluble form of VEGFR-1 in vitro also increased. Together, the results of this study showed that VEGF family members regulate Cytotrophoblast survival and that expression of a subset of family members is dysregulated in severe forms of preeclampsia.
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vascular endothelial growth factor ligands and receptors that regulate human Cytotrophoblast survival are dysregulated in severe preeclampsia and hemolysis elevated liver enzymes and low platelets syndrome
American Journal of Pathology, 2002Co-Authors: Yan Zhou, Michael T Mcmaster, Mary Janatpour, Jean Perry, Terhi Karpanen, Kari Alitalo, Caroline H Damsky, Kirstin Woo, Susan J FisherAbstract:Human placental development combines elements of tumorigenesis and vasculogenesis. The organ's specialized epithelial cells, termed Cytotrophoblasts, invade the uterus where they reside in the interstitial compartment. They also line uterine arteries and veins. During invasion, ectodermally derived Cytotrophoblasts undergo pseudovasculogenesis, switching their adhesion molecule repertoire to mimic that of vascular cells. Failures in this transformation accompany the pregnancy complication preeclampsia. Here, we used a combination of in situ and in vitro analyses to characterize the cell's expression of vascular endothelial growth factor (VEGF) family ligands and receptors, key regulators of conventional vasculogenesis and angiogenesis. Cytotrophoblast differentiation and invasion during the first and second trimesters of pregnancy were associated with down-regulation of VEGF receptor (VEGFR)-2. Invasive Cytotrophoblasts in early gestation expressed VEGF-A, VEGF-C, placental growth factor (PlGF), VEGFR-1, and VEGFR-3 and, at term, VEGF-A, PlGF, and VEGFR-1. In vitro the cells incorporated VEGF-A into the surrounding extracellular matrix; PlGF was secreted. We also found that Cytotrophoblasts responded to the VEGF ligands they produced. Blocking ligand binding significantly decreased their expression of integrin α1, an adhesion molecule highly expressed by endovascular Cytotrophoblasts, and increased apoptosis. In severe preeclampsia and hemolysis, elevated liver enzymes, and low platelets syndrome, immunolocalization on tissue sections showed that Cytotrophoblast VEGF-A and VEGFR-1 staining decreased; staining for PlGF was unaffected. Cytotrophoblast secretion of the soluble form of VEGFR-1 in vitro also increased. Together, the results of this study showed that VEGF family members regulate Cytotrophoblast survival and that expression of a subset of family members is dysregulated in severe forms of preeclampsia.
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Plasma Membrane-Associated pY397FAK Is a Marker of Cytotrophoblast Invasion in Vivo and in Vitro
The American journal of pathology, 2001Co-Authors: Dusko Ilic, Caroline H Damsky, Olga Genbacev, Fang Jin, Eduardo Caceres, Eduardo A.c. Almeida, Valerie Bellingard-dubouchaud, Erik Schaefer, Susan J FisherAbstract:During human pregnancy specialized placental cells of fetal origin, termed Cytotrophoblasts, invade the uterus and its blood vessels. This tumor-like process anchors the conceptus to the mother and diverts the flow of uterine blood to the placenta. Previously, we showed that the expression of molecules with important functional roles, including a number of extracellular matrix integrin receptors, is precisely modulated during Cytotrophoblast invasion in situ. Here we exploited this observation to study the role of the focal adhesion kinase (FAK), which transduces signals from the extracellular matrix and recruits additional signaling proteins to focal adhesions. Immunolocalization studies on tissue sections showed that FAK is expressed by Cytotrophoblasts in all stages of differentiation. Because extracellular matrix-induced integrin clustering results in FAK (auto)phosphorylation on tyrosine 397 (Y397FAK), we also localized this form of the molecule. Immunolocalization experiments detected Y397FAK in a subset of Cytotrophoblasts near the surface of the uterine wall. To assess the functional relevance of this observation, we used an adenovirus strategy to inhibit Cytotrophoblast expression of FAK as the cells differentiated along the invasive pathway in vitro. Compared to control cells transduced with a wild-type virus, Cytotrophoblasts that expressed antisense FAK exhibited a striking reduction in their ability to invade an extracellular matrix substrate. When Cytotrophoblast differentiation was compromised (hypoxia in vitro, preeclampsia in vivo), Y397FAK levels associated with the plasma membrane were strikingly lower, although total FAK levels did not change. Together our results suggest that (auto)phosphorylation of Y397 on FAK is a critical component of the signaling pathway that mediates Cytotrophoblast migration/invasion.
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Human Cytotrophoblasts adopt a vascular phenotype as they differentiate. A strategy for successful endovascular invasion
The Journal of clinical investigation, 1997Co-Authors: Yan Zhou, Mary Janatpour, Susan J Fisher, Olga Genbacev, Elisabetta Dejana, M Wheelock, Caroline H DamskyAbstract:Establishment of the human placenta requires that fetal Cytotrophoblast stem cells in anchoring chorionic villi become invasive. These Cytotrophoblasts aggregate into cell columns and invade both the uterine interstitium and vasculature, anchoring the fetus to the mother and establishing blood flow to the placenta. Cytotrophoblasts colonizing spiral arterioles replace maternal endothelium as far as the first third of the myometrium. We show here that differentiating Cytotrophoblasts transform their adhesion receptor phenotype so as to resemble the endothelial cells they replace. Cytotrophoblasts in cell columns show reduced E-cadherin staining and express VE-(endothelial) cadherin, platelet-endothelial adhesion molecule-1, vascular endothelial adhesion molecule-1, and alpha-4-integrins. Cytotrophoblasts in the uterine interstitium and maternal vasculature continue to express these receptors, and, like endothelial cells during angiogenesis, also stain for alphaVbeta3. In functional studies, alphaVbeta3 and VE-cadherin enhance, while E-cadherin restrains, Cytotrophoblast invasiveness. Cytotrophoblasts expressing alpha4 integrins bound immobilized VCAM-1 in vitro, suggesting that this receptor-pair could mediate Cytotrophoblast-endothelium or Cytotrophoblast-Cytotrophoblast interactions in vivo, during endovascular invasion. In the pregnancy disorder preeclampsia, in which endovascular invasion remains superficial, Cytotrophoblasts fail to express most of these endothelial markers (Zhou et al., 1997. J. Clin. Invest. 99:2152-2164.), suggesting that this adhesion phenotype switch is required for successful endovascular invasion and normal placentation.
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Human placental HLA-G expression is restricted to differentiated Cytotrophoblasts.
Journal of immunology (Baltimore Md. : 1950), 1995Co-Authors: Michael T Mcmaster, Yan Zhou, Mary Janatpour, Caroline H Damsky, Clifford Librach, Kee-hak Lim, Robert Demars, Susan Kovats, Susan J FisherAbstract:Human placental trophoblasts lie at the maternal-fetal interface, a position in which they could play an important role in maternal tolerance of the fetal semi-allograft. Central to this hypothesis is their unusual MHC class I expression: they suppress class Ia production while expressing HLA-G, a class Ib molecule. We investigated human trophoblast HLA-G protein production in vivo and in vitro. We first used a synthetic peptide corresponding to the variable sequence of the alpha 1 domain to produce mAbs that recognized HLA-G. Ab specificity was demonstrated by immunoaffinity purification of a single protein with the same molecular mass (38 kDa) as HLA-G from choriocarcinoma cells. Use of these Abs to stain tissue sections of the maternal-fetal interface containing Cytotrophoblasts in all stages of differentiation showed that HLA-G is expressed only by Cytotrophoblasts that invade the uterus. Our previous in vitro studies showed that when early-gestation Cytotrophoblast stem cells are cultured, they differentiate rapidly along the invasive pathway, as demonstrated by their expression of stage-specific markers. Here we show they also up-regulate HLA-G production. Cytotrophoblasts from term placentas, which have reduced invasive capacity in vitro, also had decreased ability to up-regulate HLA-G protein expression. We detected high levels of HLA-G mRNA in Cytotrophoblasts isolated from first- and second-trimester placentas, but only trace amounts in term cells. Taken together, these results suggest that HLA-G production is a critical component of Cytotrophoblast differentiation along the invasive pathway.
