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Placental epigenetics, a window on fetal life
Journal of Reproductive Immunology 94 (2012) 5–130
Contents lists available at SciVerse ScienceDirect
Journal of Reproductive Immunology journal homepage: www.elsevier.com/locate/jreprimm
Abstracts
Session 1 Genetic and Epigenetic Regulation of Genomic Imprinting and Fetal Development IS 01 Epigenetic regulation of trophoblast differentiation and antigen repertoire expression to ensure normal uterine vascularization and fetal growth M. Hemberger Epigenetics Programme, The Babraham Institute, Cambridge, UK BACKGROUND: We are interested in genetic and epigenetic factors that contribute to early cell lineage commitment and differentiation of trophoblast cells to form the future placenta. We have found that an unusual MHC antigen repertoire on the surface of murine trophoblast giant cells directs immune interactions with uterine natural killer (uNK) cells. Strikingly, this immune recognition of the conceptus by the maternal immune system affects the extent of spiral artery remodelling and, as a consequence, placental blood supply and fetal growth rates. Our interest is how differentiation of these specific trophoblast cells is epigenetically regulated and may thus be vulnerable to modulation by extrinsic factors. METHODS: We employed MeDIP-Seq to identify the DNA methylation profiles of stem cells representative of the distinct cell lineages of the early mouse embryo, as well as of trophoblast stem and giant cell enriched compartments in vivo. We also investigate conceptuses developed in the absence of the maintenance DNA methyltransferase, Dnmt1. RESULTS: As trophoblast stem cells differentiate towards giant cells, they up-regulate several surface antigens including those known to interact with uNK cell receptors. DNA methylation profiling identified distinct targets under tight epigenetic control that define the trophoblast cell lineage. Our combined approaches show that the balance between the trophoblast stem cell compartment and differentiation into giant cells is disturbed in 0165-0378/$ – see front matter doi:10.1016/j.jri.2012.03.001
conceptuses globally hypomethylated due to absence of Dnmt1. Therefore, DNA methylation regulates trophoblast differentiation and consequently expression of giant cellcharacteristic surface antigens. CONCLUSIONS: Global DNA methylation patterns are a defining feature of each stem cell type that regulate developmental programmes underpinning lineage commitment and differentiative potency of early embryo-derived stem cells. Differentiation within the trophoblast lineage is further controlled by Dnmt1 to modulate the balance between trophoblast stem and giant cells. Key target genes under epigenetic regulation are thus responsible to establish the expression profile, including of surface antigens, characteristic for trophoblast giant cells at the feto-maternal interface. doi:10.1016/j.jri.2012.03.244 IS 02 Placental epigenetics, a window on fetal life J.F. Padbury Professor and Vice Chair, Brown Alpert Medical School, Pediatrician-in-Chief, Women & Infants’ Hospital, Rhode Island, USA There are few settings in which gene-environment interactions are more profound, the critical windows are narrower, and the latency to onset of effect is shorter than the influence of an adverse intrauterine environment on fetal development. The placenta is the first complex fetal organ to form during development. Once developed it serves as the source of fetal nutrients, water, gas exchange, excretion, and immune regulation. These effects are modulated by simultaneous production of many pregnancy related hormones, proteins and growth factors thereby fulfilling a critical role in proper intrauterine development. Also crucial is the placenta’s role in protecting the developing fetus from environmental insults. The placenta as a modulator of the intrauterine milieu through changes in
6
Abstracts / Journal of Reproductive Immunology 94 (2012) 5–130
gene expression hormonal signals functions as a mediator in the regulation of neuroendocrine-metabolic processes of pregnancy and determines the perinatal well-being of the fetus. The “fetal origins” hypothesis developed from a series of studies which demonstrated that measures of birth size are associated with long-term chronic disease risk. The majority of studies have focused on cardiovascular disease and metabolic syndromes. Numerous investigations have shown that antenatal environmental factors, including diet, xenobiotics exposures, stress, and lifestyle factors can alter fetal growth and, through programming, result in permanent biological and physiologic changes in the offspring. Many of the acquired adverse effects related to the intrauterine environment result in epigenetic alterations. This critical role of epigenetic regulation, the mitotically and meiotically heritable control of gene expression not related to DNA sequence, during development is becoming increasingly appreciated. These epigenetic alterations lead to changes in gene expression which alter the function of the placenta as regulator of the fetal environment. Our recent studies have demonstrated the effects of an adverse intrauterine environment on the placental epigenome at both the candidate gene and genome wide level. Our results demonstrate that the interaction between genes and environment can be captured in the placental epigenome which exerts down-stream effects on fetal development. We have shown that the methylation profile of the placenta is more robust than any of a myriad of other tissues examined. We have evaluated the effect of the intrauterine environment on genome-wide placental DNA methylation and its association with birth weight, the effects of the intrauterine environment on methylation of repetitive element DNA, changes in placental gene expression, the association of the methylation of repetitive elements with fetal growth, and the effects of maternal smoking and birth weight on placental micro RNA expression. These changes are all part of the emerging paradigm that the placenta, at the interface between the fetus and the maternal and extrauterine environment is not a passive player but an active mediator of fetal well-being. Nonetheless, environmental insults can overwhelm the ability of the placenta to maintain intrauterine homeostasis and result in preterm birth. We see the placental epigenome an “integrated blue-print” of intrauterine life. The patterns of alteration in the placental epigenome serve to “tell the story” of the insults associated with adverse intrauterine life. doi:10.1016/j.jri.2012.03.245 IS 03 Gestational diabetes, inflammation and obesity: new insights into genetic markers and phenotype S. Daher Obstetrics Department, Federal University of São Paulo, São Paulo, Brazil The incidence of Gestational diabetes mellitus (GDM) and obesity is rising worldwide. Both conditions have in common a state of chronic, low-grade subclinical inflammation. Different evidences have shown that high
inflammatory cytokines and adipokines secretion may aggravate insulin resistance in pregnancy and participate in the pathogenesis of GDM. Environmental condition and genetic factors are recognized as major contributors to this complex process. However, up to the moment it is still unclear which are the essential factors that interfere with pregnancy outcome. Some studies have analyzed inflammatory gene polymorphisms in women of different BMIs with gestational diabetes with controversial results. In order to clarify these aspects, we have been searching for phenotype and genotype markers of risk for GDM. In this scenario, we included diverse molecules and snps related to the most important inflammatory and anti-inflammatory cytokines, and also to adipokines. Besides genetic analysis, we sought to examine the potential value of maternal serum levels of inflammatory and anti-inflammatory cytokines and adipokines in early pregnancy as potential biomarkers in the prediction of GDM, and also whether these findings are dependent of body mass index. Although we have found some important and interesting correlations, until now we are still trying to understand which are the essential pathogenic factors involved in this disease. Since GDM is a complex disease, it is probable that its development is the result of a combination of factors. Based on this premise, we are currently assessing a combination of SNPs, as well as serum levels and/or in vitro production of the corresponding mediators. We envision this will be a promising and instigating new area of research for the coming years and hope that our new findings will help to shed light on the ethiopathogenic factors involved in GDM. doi:10.1016/j.jri.2012.03.246 OP 01 STOX1 overexpression in mice induces severe preeclampsia-like symptoms prevented by aspirin at low doses L. Doridot 1,2,3,∗ , B. Passet 4 , C. Méhats 1,2,3 , S. Barbaux 1,2,3 , F. Mondon 1,2,3 , M. Vilotte 4 , J. Castille 4 , M. Breuiller-Fouche 1,2,3 , S. Jacques 1,2,3 , J.-L. Vilotte 4 , D. Vaiman 1,2,3 1
Institut national de la santé et de la recherche médicale (INSERM), U1016, Institut Cochin, Paris, France 2 Centre national de la recherche scientifique (NRS), UMR(S) 8104, Paris, France 3 Université Paris Descartes, Paris, France 4 Institut national de la recherche agronomique (NRA), UMR1313, Génétique Animale et Biologie Intégrative, Jouyen-Josas, France Preeclampsia is a very common disorder, specific of human pregnancy, affecting 5-7% of pregnant women, and responsible for maternal and foetal morbidity and mortality. It is characterized by the emergence of hypertension and proteinuria after the 20th week of pregnancy, followed by increasingly severe symptoms up until the delivery of placenta (and fetus), generally induced preterm. It is a pathology for which a real lack of spontaneous animal model is a great issue.
Contents lists available at SciVerse ScienceDirect
Journal of Reproductive Immunology journal homepage: www.elsevier.com/locate/jreprimm
Abstracts
Session 1 Genetic and Epigenetic Regulation of Genomic Imprinting and Fetal Development IS 01 Epigenetic regulation of trophoblast differentiation and antigen repertoire expression to ensure normal uterine vascularization and fetal growth M. Hemberger Epigenetics Programme, The Babraham Institute, Cambridge, UK BACKGROUND: We are interested in genetic and epigenetic factors that contribute to early cell lineage commitment and differentiation of trophoblast cells to form the future placenta. We have found that an unusual MHC antigen repertoire on the surface of murine trophoblast giant cells directs immune interactions with uterine natural killer (uNK) cells. Strikingly, this immune recognition of the conceptus by the maternal immune system affects the extent of spiral artery remodelling and, as a consequence, placental blood supply and fetal growth rates. Our interest is how differentiation of these specific trophoblast cells is epigenetically regulated and may thus be vulnerable to modulation by extrinsic factors. METHODS: We employed MeDIP-Seq to identify the DNA methylation profiles of stem cells representative of the distinct cell lineages of the early mouse embryo, as well as of trophoblast stem and giant cell enriched compartments in vivo. We also investigate conceptuses developed in the absence of the maintenance DNA methyltransferase, Dnmt1. RESULTS: As trophoblast stem cells differentiate towards giant cells, they up-regulate several surface antigens including those known to interact with uNK cell receptors. DNA methylation profiling identified distinct targets under tight epigenetic control that define the trophoblast cell lineage. Our combined approaches show that the balance between the trophoblast stem cell compartment and differentiation into giant cells is disturbed in 0165-0378/$ – see front matter doi:10.1016/j.jri.2012.03.001
conceptuses globally hypomethylated due to absence of Dnmt1. Therefore, DNA methylation regulates trophoblast differentiation and consequently expression of giant cellcharacteristic surface antigens. CONCLUSIONS: Global DNA methylation patterns are a defining feature of each stem cell type that regulate developmental programmes underpinning lineage commitment and differentiative potency of early embryo-derived stem cells. Differentiation within the trophoblast lineage is further controlled by Dnmt1 to modulate the balance between trophoblast stem and giant cells. Key target genes under epigenetic regulation are thus responsible to establish the expression profile, including of surface antigens, characteristic for trophoblast giant cells at the feto-maternal interface. doi:10.1016/j.jri.2012.03.244 IS 02 Placental epigenetics, a window on fetal life J.F. Padbury Professor and Vice Chair, Brown Alpert Medical School, Pediatrician-in-Chief, Women & Infants’ Hospital, Rhode Island, USA There are few settings in which gene-environment interactions are more profound, the critical windows are narrower, and the latency to onset of effect is shorter than the influence of an adverse intrauterine environment on fetal development. The placenta is the first complex fetal organ to form during development. Once developed it serves as the source of fetal nutrients, water, gas exchange, excretion, and immune regulation. These effects are modulated by simultaneous production of many pregnancy related hormones, proteins and growth factors thereby fulfilling a critical role in proper intrauterine development. Also crucial is the placenta’s role in protecting the developing fetus from environmental insults. The placenta as a modulator of the intrauterine milieu through changes in
6
Abstracts / Journal of Reproductive Immunology 94 (2012) 5–130
gene expression hormonal signals functions as a mediator in the regulation of neuroendocrine-metabolic processes of pregnancy and determines the perinatal well-being of the fetus. The “fetal origins” hypothesis developed from a series of studies which demonstrated that measures of birth size are associated with long-term chronic disease risk. The majority of studies have focused on cardiovascular disease and metabolic syndromes. Numerous investigations have shown that antenatal environmental factors, including diet, xenobiotics exposures, stress, and lifestyle factors can alter fetal growth and, through programming, result in permanent biological and physiologic changes in the offspring. Many of the acquired adverse effects related to the intrauterine environment result in epigenetic alterations. This critical role of epigenetic regulation, the mitotically and meiotically heritable control of gene expression not related to DNA sequence, during development is becoming increasingly appreciated. These epigenetic alterations lead to changes in gene expression which alter the function of the placenta as regulator of the fetal environment. Our recent studies have demonstrated the effects of an adverse intrauterine environment on the placental epigenome at both the candidate gene and genome wide level. Our results demonstrate that the interaction between genes and environment can be captured in the placental epigenome which exerts down-stream effects on fetal development. We have shown that the methylation profile of the placenta is more robust than any of a myriad of other tissues examined. We have evaluated the effect of the intrauterine environment on genome-wide placental DNA methylation and its association with birth weight, the effects of the intrauterine environment on methylation of repetitive element DNA, changes in placental gene expression, the association of the methylation of repetitive elements with fetal growth, and the effects of maternal smoking and birth weight on placental micro RNA expression. These changes are all part of the emerging paradigm that the placenta, at the interface between the fetus and the maternal and extrauterine environment is not a passive player but an active mediator of fetal well-being. Nonetheless, environmental insults can overwhelm the ability of the placenta to maintain intrauterine homeostasis and result in preterm birth. We see the placental epigenome an “integrated blue-print” of intrauterine life. The patterns of alteration in the placental epigenome serve to “tell the story” of the insults associated with adverse intrauterine life. doi:10.1016/j.jri.2012.03.245 IS 03 Gestational diabetes, inflammation and obesity: new insights into genetic markers and phenotype S. Daher Obstetrics Department, Federal University of São Paulo, São Paulo, Brazil The incidence of Gestational diabetes mellitus (GDM) and obesity is rising worldwide. Both conditions have in common a state of chronic, low-grade subclinical inflammation. Different evidences have shown that high
inflammatory cytokines and adipokines secretion may aggravate insulin resistance in pregnancy and participate in the pathogenesis of GDM. Environmental condition and genetic factors are recognized as major contributors to this complex process. However, up to the moment it is still unclear which are the essential factors that interfere with pregnancy outcome. Some studies have analyzed inflammatory gene polymorphisms in women of different BMIs with gestational diabetes with controversial results. In order to clarify these aspects, we have been searching for phenotype and genotype markers of risk for GDM. In this scenario, we included diverse molecules and snps related to the most important inflammatory and anti-inflammatory cytokines, and also to adipokines. Besides genetic analysis, we sought to examine the potential value of maternal serum levels of inflammatory and anti-inflammatory cytokines and adipokines in early pregnancy as potential biomarkers in the prediction of GDM, and also whether these findings are dependent of body mass index. Although we have found some important and interesting correlations, until now we are still trying to understand which are the essential pathogenic factors involved in this disease. Since GDM is a complex disease, it is probable that its development is the result of a combination of factors. Based on this premise, we are currently assessing a combination of SNPs, as well as serum levels and/or in vitro production of the corresponding mediators. We envision this will be a promising and instigating new area of research for the coming years and hope that our new findings will help to shed light on the ethiopathogenic factors involved in GDM. doi:10.1016/j.jri.2012.03.246 OP 01 STOX1 overexpression in mice induces severe preeclampsia-like symptoms prevented by aspirin at low doses L. Doridot 1,2,3,∗ , B. Passet 4 , C. Méhats 1,2,3 , S. Barbaux 1,2,3 , F. Mondon 1,2,3 , M. Vilotte 4 , J. Castille 4 , M. Breuiller-Fouche 1,2,3 , S. Jacques 1,2,3 , J.-L. Vilotte 4 , D. Vaiman 1,2,3 1
Institut national de la santé et de la recherche médicale (INSERM), U1016, Institut Cochin, Paris, France 2 Centre national de la recherche scientifique (NRS), UMR(S) 8104, Paris, France 3 Université Paris Descartes, Paris, France 4 Institut national de la recherche agronomique (NRA), UMR1313, Génétique Animale et Biologie Intégrative, Jouyen-Josas, France Preeclampsia is a very common disorder, specific of human pregnancy, affecting 5-7% of pregnant women, and responsible for maternal and foetal morbidity and mortality. It is characterized by the emergence of hypertension and proteinuria after the 20th week of pregnancy, followed by increasingly severe symptoms up until the delivery of placenta (and fetus), generally induced preterm. It is a pathology for which a real lack of spontaneous animal model is a great issue.