ECIBC at a Glance: European Commission Initiative on Breast Cancer

This document is a brochure explaining the EICBC initiative to a middle-informed audience. ECIBC provides evidence based guidelines and a European Quality assurance scheme for breast cancer.JRC.F.1-Health in Societ

The Future of Cities

This report is an initiative of the Joint Research Centre (JRC), the science and knowledge service of the European Commission (EC), and supported by the Commission's Directorate-General for Regional and Urban Policy (DG REGIO). It highlights drivers shaping the urban future, identifying both the key challenges cities will have to address and the strengths they can capitalise on to proactively build their desired futures. The main aim of this report is to raise open questions and steer discussions on what the future of cities can, and should be, both within the science and policymaker communities. While addressing mainly European cities, examples from other world regions are also given since many challenges and solutions have a global relevance. The report is particularly novel in two ways. First, it was developed in an inclusive manner – close collaboration with the EC’s Community of Practice on Cities (CoP-CITIES) provided insights from the broader research community and city networks, including individual municipalities, as well as Commission services and international organisations. It was also extensively reviewed by an Editorial Board. Secondly, the report is supported by an online ‘living’ platform which will host future updates, including additional analyses, discussions, case studies, comments and interactive maps that go beyond the scope of the current version of the report. Steered by the JRC, the platform will offer a permanent virtual space to the research, practice and policymaking community for sharing and accumulating knowledge on the future of cities. This report is produced in the framework of the EC Knowledge Centre for Territorial Policies and is part of a wider series of flagship Science for Policy reports by the JRC, investigating future perspectives concerning Artificial Intelligence, the Future of Road Transport, Resilience, Cybersecurity and Fairness Interactive online platform : https://urban.jrc.ec.europa.eu/thefutureofcitiesJRC.B.3-Territorial Developmen

In utero exposure to xenoestrogens, associated health outcomes and epigenetic mechanisms in children

The prenatal period is a stage of special sensitivity to the adverse effects of environmental agents for the developing fetus. The human placenta is an organ that, in the interface between mother and fetus, plays a key role in fetal growth and development and, as such, affects the fetal programming underlying subsequent disease vulnerability in adulthood. There is increasing epidemiological evidence linking prenatal exposure to endocrine disrupting chemicals (EDCs) and adverse health outcomes in children, although mechanisms remain still unclear. Xenoestrogens are a group of endocrine disrupting chemicals that target the estrogenic signaling pathway and include a large number of compounds, both man-made and of natural origin, ubiquitously present in the environment, often at low doses. Xenoestrogen exposure has been related both in humans and in animal models to adverse health endpoints, most especially obesity and metabolic disorders, reproductive problems, increased risk for several types of cancers and neurobehavioral abnormalities. Prenatal epigenetic dysregulation has been proposed as a possible causal mechanism. The main objective of this thesis has been to evaluate the effects of prenatal exposure to mixtures of xenoestrogens on growth related and neuropsychological outcomes in children from the prospective Spanish birth cohort study INMA, INfancia y Medio Ambiente (Childhood and the Environment) Project, and to analyze whether in utero exposure to mixtures produces changes in placental DNA methylation, both globally or at specific genes and/or nearby regions. For that purpose, the Total Effective Xenoestrogen Burden (TEXB-alpha), a biomarker of the cumulative exposure to xenoestrogens, was measured in placental tissue using the E-Screen biossay. Information on birth outcomes was recorded by pediatricians or nurses at birth and at following time points, and neuropsychological assessment was conducted by trained psychologists using two different scales when children were around 2 and 4 years of age. DNA methylation was measured on DNA extracted from placenta for a sub-group of children using quantitative methods. We evaluated global DNA methylation by bisulfite pyrosequencing of several retrotransposons (repetitive elements that make up around 42% of the human genome); and genome-wide DNA methylation was scanned with a comprehensive array provided by Illumina, the HumanMethylation450 BeadChip, in which practically all human genes and many regulatory regions are represented. Associations were tested using linear regression, mixed-effects regression or robust linear regression models accordingly, always adjusting for potential confounders and sex specific effects were investigated. Overall, we found significant associations between TEXB-alpha exposure in boys but not in girls and the outcomes studied: higher TEXB-alpha levels were associated with increasing birthweight and with a decrease in motor performance at age 1-2 years, which did not persist at age 4. Additionally, we found some evidence that xenoestrogen exposure produced a decrease in placenta global DNA methylation in an Alu element in boys and, although non-significant after multiple testing correction, induced changes in DNA methylation in boys in CpG sites located in several genes (i.e. LRPAP1, HAGH, PPARGC1B,KCNQ1 and KCNQ1DN), previously associated either to birthweight and Type 2 Diabetes, obesity or to steroid hormone metabolism and signalling. Results from this work on chidren from the general Spanish population suggest that low-level exposure to mixtures of hormonally active estrogenic compounds may produce growth-related changes and some adverse effects on the early development of motor tasks in the male population, and are suggestive of epigenetic disruption in global methylation in the same group, while the association with specific genes in boys remains unclear and needs to be evaluated in larger samples and using alternative methods. This thesis has analyzed for the first time in an epidemiological study a biomarker of exposure to mixtures of xenoestrogens in placenta in relation to birthweight, children growth, body mass index and neuropsychological development, adding knowledge to the limited evidence that prenatal xenoestrogen exposure could be relevant in terms of children health outcomes, that epigenetic alterations may play a mechanistic role and highlights the importance to take into account possible sex-related vulnerability to EDCs during pregnancy.El període prenatal és una etapa sensible als efectes de l’exposició a agents ambientals. La placenta humana, un òrgan que comunica la mare i el fetus i que, durant aquest període, juga un paper clau en el creixement i el desenvolupament fetal. Com a tal, la placenta podria estar implicada en alteracions fenotípiques ja visibles en la infància i amb possibles efectes en salut a llarg termini. Existeix evidència epidemiològica que relaciona l’exposició prenatal a pertorbadors endocrins (EDCs, de l’ anglés endocrine disrupting chemicals) amb diferents indicadors de salut infantil, tot i que els mecanismes d’acció són encara poc coneguts. Els xenoestrògens són un grup d’EDCs que interfereixen amb les vies de senyalització de les hormones estrogèniques. Inclouen un ampli ventall de compostos, alguns d’origen natural i d’altres sintètic, omnipresents en el medi ambient, sovint a baixes concentracions. Un nombre important d’estudis científics han trobat associacions, tant en humans com en models animals, entre l’exposició prenatal a aquests compostos i alteracions metabòliques, obesitat, problemes reproductius, un augment de risc de patir diferents tipus de càncer i alteracions en el desenvolupament de funcions neuropsicològiques. Un possible mecanisme molecular proposat per molts investigadors que podria explicar, almenys en part, aquestes associacions és l’alteració de patrons epigenètics durant el període prenatal. L’objectiu principal d’aquest projecte de tesi ha estat avaluar l’associació entre l’exposició prenatal a mescles de compostos xenoestrogènics i el pes al naixement, la velocitat de creixement durant els 6 primers mesos i l’índex de massa corporal als 14 mesos, així com el desenvolupament neuropsicològic a diferents edats en nens de la cohort espanyola de naixement INMA (INfància i Medi Ambient), i també estudiar si aquesta exposició produeix canvis en la metilació del DNA en la placenta, a nivell global i/o en gens específics o possibles regions reguladores del genoma. Amb aquest propòsit, vam mesurar en placenta l’efecte estrogènic degut a mescles de compostos ambientals mitjançant un biomarcador anomenat Total Effective Xenoestrogen Burden (TEXB-alfa) usant l’assaig E-Screen, basat en la proliferació de cèl.lules tumorals MCF que responen a estrògens. La informació referent al pes al néixer i altres variables de creixement va ser recollida per pediatres i/o infermeres i l’avaluació neuropsicològica va ser realitzada per psicòlegs entrenats amb experiència prèvia en l’administració de les dues escales utilitzades. En un subgrup de nens, es va analitzar la metilació del DNA en placenta amb diferents mètodes quantitatius. A nivell global la vam estimar mesurant el percentatge de citosines metilades en unes seqüències repetides que constitueixen fins a un 42% del total del genoma humà anomenades retrotransposons usant la tècnica de piroseqüenciació i, per altra banda, es van mesurar els nivells de metilació de forma quantitativa en un gran nombre de citosines distribuïdes al llarg de tot el genoma, incloent pràcticament tots els gens descrits i moltes regions reguladores, amb un array produït per la casa comercial Illumina anomenat HumanMethylation450 BeadChip. Les corresponents associacions van ser analitzades usant models de regressió lineals, models de regressió lineal mixta (per a tenir en compte mesures repetides o correlacionades) i regressions lineals robustes, ajustant per potencials variables confusores. En tots els casos es va estudiar l’existència d’efectes diferents en funció del sexe dels nens. Els resultats obtinguts en aquesta tesi mostren l’existència d’associacions entre l’exposició prenatal a TEXB-alpha i els diferents fenotips estudiats en els nens però no en les nenes: en aquests, nivells alts de TEXB-alpha es relacionaven amb un augment significatiu del pes al néixer i alteracions neuropsicològiques, concretament una disminució en les puntuacions de l’escala motora al voltant dels 2 anys, tot i que aquest últim efecte ja no el trobàvem als 4 anys d’edat. També vam observar una disminució en els nens amb nivells alts de TEXB-alpha en la metilació en placenta d’un element repetitiu anomenat AluYb8, que representa un indicador de la metilació global del genoma i, tot i no ser significatius a nivell estadístic, vam trobar canvis en la metilació en nens en uns CpGs situats en gens (LRPAP1, HAGH, PPARGC1B, KCNQ1 i KCNQ1DN) que en estudis anteriors s’havien relacionat amb el pes al néixer, la obesitat, la diabetis de tipus II i el metabolisme i la resposta a hormones esteroides com l’estrògen. Aquests resultats, obtinguts en població general infantil espanyola, suggereixen que l’exposició constant i a baixes dosis a mescles de compostos actius a nivell hormonal podrien afectar el creixement i tenir un impacte en el desenvolupament inicial de funcions cerebrals en la població masculina, i aporten evidència de canvis en els nivells de metilació global en aquesta població, mentre que les associacions observades en relació a gens concrets són incertes i caldran més estudis en altres cohorts més nombroses i validacions tècniques usant altres mètodes. Finalment, aquesta tesi ha realitzat per primer cop un estudi epidemiològic usant un biomarcador d’exposició conjunta a mescles de xenoestrògens en placenta en relació a variables de creixement i desenvolupament neuropsicològic, i aporta nou coneixement a l’evidència científica existent, tot i que limitada, de què l’exposició prenatal a xenoestrògens pot tenir un impacte en la salut infantil, que alteracions en la metilació del DNA podrien jugar un paper mecanístic en aquests efectes observats i, finalment, destaquen la importància d’estudiar la possible vulnerabilitat diferencial entre nens i nenes a l’exposició in utero a pertorbadors endocrins

Storage conditions and stability of global DNA methylation in placental tissue

AIM: The placenta is an informative and easily available tissue for many epidemiological studies. We analyzed the extent to which storage delay affects DNA methylation. MATERIAL & METHODS: Biopsies from two placentas were sequentially stored at -80°C after standing at room temperature for 30 min, 1 h, 2 h, 6 h and 24 h. Global DNA methylation was measured by bisulfite pyrosequencing of repetitive elements and the luminometric methylation assay. RESULTS: Small changes in global DNA methylation in relation to time-to-storage were observed by pyrosequencing, with a coefficient of variation (COV) of 2.49% (placenta 1) and 2.86% (placenta 2), similar to the mean technical variation observed for pyrosequencing (COV: 1.91 and 1.51%, respectively). A luminometric methylation assay yielded more variable results in the two placentas analyzed, both among time points (COV: 9.13 and 10.35%, respectively) and technical replicates (COV: 11.60 and 9.80%, respectively). CONCLUSION: Global DNA methylation is stable at room temperature. However, some techniques to measure methylation might be confounded by DNA degradation caused by a delay in storage.This study was funded by grants from the Spanish Ministry of Health (FIS-PI041436 and PI11/00610), Instituto de Salud Carlos III (Red Infancia y MedioAmbiente G03/176 and CB06/02/0041) and the Generalitat de Catalunya-Comissió Interdepartamental de Recerca i Innovació Tecnològica 1999SGR 00241. AA Baccarelli receives support from the Harvard School of Public Health and National Institute of Environmental Health Sciences Center for Environmental Health (ES000002). N Vilahur was supported by a Formación de Personal Investigador Grant from the Spanish Ministry of Health and a Formación de Personal Investigador Grant for Short Research Stays in Foreign Institutions (BES-2009-023933) and MF Fernandez by the Ramon y Cajal Research Grant from the Spanish Ministry of Educatio

Storage conditions and stability of global DNA methylation in placental tissue

AIM: The placenta is an informative and easily available tissue for many epidemiological studies. We analyzed the extent to which storage delay affects DNA methylation. MATERIAL & METHODS: Biopsies from two placentas were sequentially stored at -80°C after standing at room temperature for 30 min, 1 h, 2 h, 6 h and 24 h. Global DNA methylation was measured by bisulfite pyrosequencing of repetitive elements and the luminometric methylation assay. RESULTS: Small changes in global DNA methylation in relation to time-to-storage were observed by pyrosequencing, with a coefficient of variation (COV) of 2.49% (placenta 1) and 2.86% (placenta 2), similar to the mean technical variation observed for pyrosequencing (COV: 1.91 and 1.51%, respectively). A luminometric methylation assay yielded more variable results in the two placentas analyzed, both among time points (COV: 9.13 and 10.35%, respectively) and technical replicates (COV: 11.60 and 9.80%, respectively). CONCLUSION: Global DNA methylation is stable at room temperature. However, some techniques to measure methylation might be confounded by DNA degradation caused by a delay in storage.This study was funded by grants from the Spanish Ministry of Health (FIS-PI041436 and PI11/00610), Instituto de Salud Carlos III (Red Infancia y MedioAmbiente G03/176 and CB06/02/0041) and the Generalitat de Catalunya-Comissió Interdepartamental de Recerca i Innovació Tecnològica 1999SGR 00241. AA Baccarelli receives support from the Harvard School of Public Health and National Institute of Environmental Health Sciences Center for Environmental Health (ES000002). N Vilahur was supported by a Formación de Personal Investigador Grant from the Spanish Ministry of Health and a Formación de Personal Investigador Grant for Short Research Stays in Foreign Institutions (BES-2009-023933) and MF Fernandez by the Ramon y Cajal Research Grant from the Spanish Ministry of Educatio

In utero exposure to mixtures of xenoestrogens and child neuropsychological development

BACKGROUND: To date, no epidemiological studies have explored the impact and persistence of in utero exposure to mixtures of xenoestrogens on the developing brain. We aimed to assess whether the cumulative effect of xenoestrogens in the placenta is associated with altered infant neuropsychological functioning at two and at four years of age, and if associations differ among boys and girls. METHODS: Cumulative prenatal exposure to xenoestrogens was quantified in the placenta using the biomarker Total Effective Xenoestrogen Burden (TEXB-alpha) in 489 participants from the INMA (Childhood and the Environment) Project. TEXB-alpha was split in tertiles to test its association with the mental and psychomotor scores of the Bayley Scales of Infant Development (BSID) at 1-2 years of age, and with the McCarthy Scales of Children׳s Abilities (MSCA) general cognitive index and motor scale assessed at 4-5 years of age. Interactions with sex were investigated. RESULTS: /nAfter adjustment for potential confounders, no association was observed between TEXB-alpha and mental scores at 1-2 years of age. We found a significant interactions with sex for the association between TEXB-alpha and infant psychomotor development (interaction p-value=0.029). Boys in the third tertile of exposure scored on average 5.2 points less than those in the first tertile on tests of motor development at 1-2 years of age (p-value=0.052), while no associations were observed in girls. However, this association disappeared in children at 4-5 years of age and no association between TEXB-alpha and children׳s cognition was found. CONCLUSIONS: Our results suggest that boys' early motor development might be more vulnerable to prenatal exposure to mixtures of xenoestrogens, but associations do not persist in preschool children.This work was supported by grants from the Spanish Ministry of Health [FIS-PI042018; FIS-PI060867; FIS-PI081151; FIS-PI09/02311; FIS-PI09/02647; FIS-PI11/00610 Council of Innovation, Science and Enterprise (Excellence Project P09-CTS-5488) and Council of Health (SAS PI-0675-2010), Instituto de Salud Carlos III [Red INMA G03/176 and CB06/02/0041]; the EU Commission (QLK4-1999-01422, QLK4-2002-00603 and CONTAMED FP7-ENV-212502), the Generalitat de Catalunya-CIRIT [1999SGR 00241]; the Fundació La Marató de TV3 (Grant no. 090430); the Consejería de Salud de la Junta de Andalucía (Grant number 183/07 and 0675/10), the Diputación Foral de Gipuzkoa (DFG06/004), the Department of Health of the Basque Government (2005111093), the University of Oviedo, Obra Social Cajastur, and the Fundación Roger Torné. NV was supported by an FPI Grant from the Spanish Ministry of Health (BES-2009-023933) and a Formación de Personal Investigador Grant for Short Research Stays in Foreign Institutions (BES-2009-023933). The HUSC BioBank, integrated in the Andalusia Public Health System (SSPA) and the National Biobank Network, is financed by the Institute of Health Carlos III, (Project RD09/0076/00148) and the Regional Government of Andalusi

Prenatal ambient air pollution, placental mitochondrial DNA content, and birth weight in the INMA (Spain) and ENVIRONAGE (Belgium) birth cohorts.

BACKGROUND: Mitochondria are sensitive to environmental toxicants due to their lack of repair capacity. Changes in mitochondrial DNA (mtDNA) content may represent a biologically relevant intermediate outcome in mechanisms linking air pollution and fetal growth restriction. OBJECTIVE: We investigated whether placental mtDNA content is a possible mediator of the association between prenatal nitrogen dioxide (NO2) exposure and birth weight. METHODS: We used data from two independent European cohorts: INMA (n = 376; Spain) and ENVIRONAGE (n = 550; Belgium). Relative placental mtDNA content was determined as the ratio of two mitochondrial genes (MT-ND1 and MTF3212/R3319) to two control genes (RPLP0 and ACTB). Effect estimates for individual cohorts and the pooled data set were calculated using multiple linear regression and mixed models. We also performed a mediation analysis. RESULTS: Pooled estimates indicated that a 10-μg/m3 increment in average NO2 exposure during pregnancy was associated with a 4.9% decrease in placental mtDNA content (95% CI: -9.3, -0.3%) and a 48-g decrease (95% CI: -87, -9 g) in birth weight. However, the association with birth weight was significant for INMA (-66 g; 95% CI: -111, -23 g) but not for ENVIRONAGE (-20 g; 95% CI: -101, 62 g). Placental mtDNA content was associated with significantly higher mean birth weight (pooled analysis, interquartile range increase: 140 g; 95% CI: 43, 237 g). Mediation analysis estimates, which were derived for the INMA cohort only, suggested that 10% (95% CI: 6.6, 13.0 g) of the association between prenatal NO2 and birth weight was mediated by changes in placental mtDNA content. CONCLUSION: Our results suggest that mtDNA content can be one of the potential mediators of the association between prenatal air pollution exposure and birth weight.The research leading to these results was funded by the Spanish Ministry of Health (FIS-PI11/00610, FIS-PI041436, FIS-PI081151, FIS-PI042018, and FIS-PI09/02311), the European Union (EU) (FP7-ENV-2011 cod 282957 and HEALTH.2010.2.4.5-1), the Instituto de Salud Carlos III (Red INMA G03/176, CB06/02/0041, FIS-FEDER 03/1615, 04/1509, 04/1112, 04/1931, 05/1079, 05/1052, 06/1213, 07/0314, 09/02647, 11/01007, 11/02591, CP11/00178, FIS-PI06/0867, and FIS-PS09/00090), the Conselleria de Sanitat Generalitat Valenciana, the Generalitat de Catalunya-CIRIT (1999SGR 00241), the Obre Social Cajastur, the Universidad de Oviedo, the Department of Health of the Basque Government (2005111093 and 2009111069), and the Provincial Government of Gipuzkoa (DFG06/004 and DFG08/001). The ENVIRONAGE cohort is supported by the EU Program “Ideas” (ERC-2012- StG 310898) and by the Flemish Fund for Scientific Research (FWO 1516112N and G073315N)

In utero exposure to mixtures of xenoestrogens and child neuropsychological development

BACKGROUND: To date, no epidemiological studies have explored the impact and persistence of in utero exposure to mixtures of xenoestrogens on the developing brain. We aimed to assess whether the cumulative effect of xenoestrogens in the placenta is associated with altered infant neuropsychological functioning at two and at four years of age, and if associations differ among boys and girls. METHODS: Cumulative prenatal exposure to xenoestrogens was quantified in the placenta using the biomarker Total Effective Xenoestrogen Burden (TEXB-alpha) in 489 participants from the INMA (Childhood and the Environment) Project. TEXB-alpha was split in tertiles to test its association with the mental and psychomotor scores of the Bayley Scales of Infant Development (BSID) at 1-2 years of age, and with the McCarthy Scales of Children׳s Abilities (MSCA) general cognitive index and motor scale assessed at 4-5 years of age. Interactions with sex were investigated. RESULTS: /nAfter adjustment for potential confounders, no association was observed between TEXB-alpha and mental scores at 1-2 years of age. We found a significant interactions with sex for the association between TEXB-alpha and infant psychomotor development (interaction p-value=0.029). Boys in the third tertile of exposure scored on average 5.2 points less than those in the first tertile on tests of motor development at 1-2 years of age (p-value=0.052), while no associations were observed in girls. However, this association disappeared in children at 4-5 years of age and no association between TEXB-alpha and children׳s cognition was found. CONCLUSIONS: Our results suggest that boys' early motor development might be more vulnerable to prenatal exposure to mixtures of xenoestrogens, but associations do not persist in preschool children.This work was supported by grants from the Spanish Ministry of Health [FIS-PI042018; FIS-PI060867; FIS-PI081151; FIS-PI09/02311; FIS-PI09/02647; FIS-PI11/00610 Council of Innovation, Science and Enterprise (Excellence Project P09-CTS-5488) and Council of Health (SAS PI-0675-2010), Instituto de Salud Carlos III [Red INMA G03/176 and CB06/02/0041]; the EU Commission (QLK4-1999-01422, QLK4-2002-00603 and CONTAMED FP7-ENV-212502), the Generalitat de Catalunya-CIRIT [1999SGR 00241]; the Fundació La Marató de TV3 (Grant no. 090430); the Consejería de Salud de la Junta de Andalucía (Grant number 183/07 and 0675/10), the Diputación Foral de Gipuzkoa (DFG06/004), the Department of Health of the Basque Government (2005111093), the University of Oviedo, Obra Social Cajastur, and the Fundación Roger Torné. NV was supported by an FPI Grant from the Spanish Ministry of Health (BES-2009-023933) and a Formación de Personal Investigador Grant for Short Research Stays in Foreign Institutions (BES-2009-023933). The HUSC BioBank, integrated in the Andalusia Public Health System (SSPA) and the National Biobank Network, is financed by the Institute of Health Carlos III, (Project RD09/0076/00148) and the Regional Government of Andalusi

Genome-wide DNA methylation study in human placenta identifies novel loci associated with maternal smoking during pregnancy

BACKGROUND: We conducted an epigenome-wide association study (EWAS) of DNA methylation in placenta in relation to maternal tobacco smoking during pregnancy and examined whether smoking-induced changes lead to low birthweight. METHODS: DNA methylation in placenta was measured using the Illumina HumanMethylation450 BeadChip in 179 participants from the INfancia y Medio Ambiente (INMA) birth cohort. Methylation levels across 431 311 CpGs were tested for differential methylation between smokers and non-smokers in pregnancy. We took forward three top-ranking loci for further validation and replication by bisulfite pyrosequencing using data of 248 additional participants of the INMA cohort. We examined the association of methylation at smoking-associated loci with birthweight by applying a mediation analysis and a two-sample Mendelian randomization approach. RESULTS: Fifty CpGs were differentially methylated in placenta between smokers and non-smokers during pregnancy [false discovery rate (FDR) < 0.05]. We validated and replicated differential methylation at three top-ranking loci: cg27402634 located between LINC00086 and LEKR1, a gene previously related to birthweight in genome-wide association studies; cg20340720 (WBP1L); and cg25585967 and cg12294026 (TRIO). Dose-response relationships with maternal urine cotinine concentration during pregnancy were confirmed. Differential methylation at cg27402634 explained up to 36% of the lower birthweight in the offspring of smokers (Sobel P-value < 0.05). A two-sample Mendelian randomization analysis provided evidence that decreases in methylation levels at cg27402634 lead to decreases in birthweight. CONCLUSIONS: We identified novel loci differentially methylated in placenta in relation to maternal smoking during pregnancy. Adverse effects of maternal smoking on birthweight of the offspring may be mediated by alterations in the placental methylome.This study was supported by grants from the Instituto de Salud Carlos III and Spanish Ministry of Health (Red INMA G03/176; CB06/02/0041; FIS 97/0588; 00/0021–2, PI061756; PS0901958; FIS-FEDER 03/1615, 04/1509, 04/1112, 04/1931, 05/1079, 05/1052, 06/1213, 07/0314, 09/02647, 11/0178, 11/01007, 11/02591, 11/02038, 13/1944, 13/2032, 14/0891 and 14/1687; Miguel Servet-FEDER CP15/00025; FIS-PI041436, FIS- PI081151, FIS-PI06/0867, FIS-PS09/00090, FIS-FEDER PI11/0610 and FIS-FEDER PI11/010007), FISS-PI042018, FISS-PI0902311, Fundació La Marató de TV3 (Project No. 090430), EC Contract No. QLK4-CT-2000–00263, Universidad de Oviedo, Conselleria de Sanitat Generalitat Valenciana, Generalitat de Catalunya-CIRIT 1999SGR 00241, the Department of Health of the Basque Government (2005111093 and 2009111069), the Provincial Government of Gipuzkoa (DFG06/004 and DFG08/001) and Fundación Roger Torné. EM is supported by a Miguel Servet Research Grant (CP14/00046) from the Instituto de Salud Carlos III, Spanish Ministry of Economy and Competitiveness, Madrid (Spain). We also acknowledge support of the Spanish Ministry of Economy and Competitiveness, Centro de Excelencia Severo Ochoa 2013–2017, SEV-2012–020

Prenatal exposure to mixtures of xenoestrogens and repetitive element DNA methylation changes in human placenta

BACKGROUND: Prenatal exposure to endocrine disrupting compounds (EDCs) has previously shown to alter epigenetic marks. OBJECTIVES: In this work we explore whether prenatal exposure to mixtures of xenoestrogens has the potential to alter the placenta epigenome, by studying DNA methylation in retrotransposons as a surrogate of global DNA methylation. METHODS: The biomarker total effective xenoestrogen burden (TEXB) was measured in 192 placentas from participants in the longitudinal INMA Project. DNA methylation was quantitatively assessed by bisulfite pyrosequencing on 10 different retrotransposons including 3 different long interspersed nuclear elements (LINEs), 4 short interspersed nuclear elements (SINEs) and 3 human endogenous retroviruses (HERVs). Associations were tested using linear mixed-effects regression models and sex interaction was evaluated.RESULTS: A significant sex interaction was observed for AluYb8 (p-value for interaction <0.001, significant at Bonferroni corrected p-value threshold of 0.0025). Boys with the highest TEXB-alpha levels of exposure (third tertile) presented on average a decrease of 0.84% in methylation compared to those in the first tertile (p-value<0.001), while no significant effects were found in girls (p-value=0.134). CONCLUSIONS: Our findings suggest that boys may be more susceptible to the effect of exposure to xenoestrogens during prenatal development, producing shifts in DNA methylation of certain sensitive genomic repetitive sequences in a tissue important for fetal growth and development.This work was supported by grants from the Spanish Ministry of Health (FIS-PI042018; FIS-PI060867; FIS-PI081151; FIS-PI09/02311; FIS-PI09/02647; FIS-PI11/00610); Instituto de Salud Carlos III [Red INMA G03/176 and CB06/02/0041]; the EU Commission (QLK4-1999-01422, QLK4-2002-00603 and CONTAMED FP7-ENV-212502), the Generalitat de Catalunya—CIRIT [1999SGR 00241]; the Consejería de Salud de la Junta de Andalucía (183/07 and 0675/10), the Diputación Foral de Gipuzkoa (DFG06/004), the Department of Health of the Basque Government (2005111093), and by the University of Oviedo, Obra Social Cajastur, the Fundación Roger Torné and La Fundació La Marató de TV3. NV was supported by an FPI Grant from the Spanish Ministry of Health (BES-2009-023933) and a Formación de Personal Investigador Grant for Short Research Stays in Foreign Institutions (BES-2009-023933). AA Baccarelli receives support from the Harvard School of Public Health and National Institute of Environmental Health Sciences Center for Environmental Health (R01 ES021357).The HUSC BioBank, integrated in the Andalusia Public Health System (SSPA) and the National Biobank Network, is financed by the Institute of Health Carlos III, (RD09/0076/00148) and the Regional Government of Andaluci