Maternal urinary concentrations of bisphenol A during pregnancy are associated with global DNA methylation in cord blood of newborns in the “NELA” birth cohort

Endocrine disrupting chemicals (EDCs) set a public health risk through disruption of normal physiological processes. The toxicoepigeneticmechanisms of developmental exposure to common EDCs, such as bisphenol A (BPA), are poorly known. The present study aimed to evaluate associations between perinatal maternal urinary concentrations of BPA, bisphenol S (BPS) and bisphenol F (BPF) and LINE-1 (long interspersed nuclear elements) and Alu (short interspersed nuclear elements, SINEs) DNA methylation levels in newborns, as surrogate markers of global DNA methylation. Data come from 318 mother-child pairs of the `Nutrition in Early Life and Asthma´ (NELA) birth cohort. Urinary bisphenol concentrationwas measured by dispersive liquid–liquid microextraction and ultrahigh performance liquid chromatography with tandem mass spectrometry detection. DNA methylation was quantitatively assessed by bisulphite pyrosequencing on 3 LINEs and 5 SINEs. Unadjusted linear regression analyses showed that higher concentration ofmaternal urinary BPA in 24th week's pregnancy was associated with an increase in LINE-1 methylation in all newborns (p = 0.01) and, particularly, in male newborns (p = 0.03). These associations remained in full adjusted models [beta = 0.09 (95 % CI = 0.03; 0.14) for all newborns; and beta= 0.10 (95 % CI = 0.03; 0.17) for males], including a non-linear association for female newborns as well (p-trend=0.003). No associations were found between maternal concentrations of bisphenol and Alu sequences. Our results suggest that exposure to environmental levels of BPA may be associated with a modest increase in LINE-1 methylation -as a relevant marker of epigenomic stability- during human fetal development. However, any effects on global DNA methylation are likely to be small, and of uncertain biological significance.Instituto de Salud Carlos III (ISCIII), Spanish Ministry of Science, Innovation and Universities, Fondos FEDER MS14/00046 CP14/00046 PIE15/00051 PI16/00422 FI17/00086 PI19/00863Fundacion Seneca, Agencia de Ciencia y Tecnologia Region de Murcia 20877/PI/18Ministry of Science and Innovation, Spain (MICINN)Spanish Government FPU18/01990ISCIII, Spanish Ministry of Science, Innovation and Universities, and Fondos FEDER MS14/00046 CPII19/0001

Exposición materna a disruptores endocrinos no persistentes y biomarcadores de salud perinatal

Introducción: Las exposiciones medioambientales durante los periodos críticos del desarrollo intrauterino se han asociado con diversos efectos adversos sobre la salud, pero los mecanismos biológicos que unirían las exposiciones con dichos efectos no se han caracterizado completamente. Por tanto, existe una falta de evidencia sobre los factores etiológicos modificables, como puede ser la exposición a compuestos disruptores endocrinos (CDEs) o el uso de fármacos durante el embarazo, y la necesidad de identificar factores de riesgo apropiados para la prevención primaria de las patologías asociadas. Los estudios sobre exposiciones ambientales y sus potenciales efectos adversos sobre la descendencia son muy escasos. Así pues, el objetivo de este estudio fue analizar la exposición materna a disruptores endocrinos no persistentes y biomarcadores de salud perinatal en una cohorte al nacimiento. Material y método: La población de estudio son 378 parejas madre-recién nacido de la cohorte al nacimiento “Nutrition in Early Life and Asthma” (NELA), implementada en la Región de Murcia (España) desde Marzo de 2015 a Abril de 2018. Se realizaron sucesivas visitas a las mujeres embarazadas a partir de la semana 20 de gestación, obteniendo información sociodemográfica, estilos de vida, consumo de medicación, así como datos de registros clínicos. La determinación urinaria de los niveles maternos de 10 CDEs (bisfenol A [BPA], bisfenol S [BPS], bisfenol F [BPF], metilparabeno [MtP], butilparabeno [BtP], propilparabeno [PrP], 2,4-dihidroxibenzofenona [BP-1], 2-hidroxi 4-metoxibenzofenona [BP-3] y 4-hidroxibenzofenona [4OH-BP]) se llevó a cabo mediante microextracción líquido-líquido dispersiva (DLLME) y cromatografía líquida de alto rendimiento, combinada con detección de espectometría de masas en tándem (UHPLC-MS/MS) en las muestras de orina materna de la semana 24 de embarazo y del parto. Además, en el parto se recogieron muestras de sangre de cordón umbilical y se realizó un examen físico de los recién nacidos, incluyendo la medición de la distancia anogenital (DAG). El porcentaje de metilación de ADN en las secuencias repetitivas LINE-1 (long interspersed nuclear elements) y Alu (short interspersed nuclear elements, SINEs) en sangre de cordón se obtuvo mediante pirosecuenciación (“Pyromark Q24”, Qiagen). La asociación entre las concentraciones urinarias maternas de CDEs y la metilación de ADN en sangre de cordón se evaluó mediante modelos de regresión lineal múltiple, además de análisis de la covarianza (ANCOVA) para examinar relaciones no monotómicas. La potencial influencia del consumo materno de paracetamol -por trimestre de gestación y durante todo el embarazo- sobre la DAG en niños se examinó también a través de modelos de regresión lineal múltiple. Así mismo, el efecto de la frecuencia de consumo de este fármaco durante el embarazo sobre la DAG se analizó mediante modelos ANCOVA. Resultados: En primer lugar, la concentración urinaria materna de BPA en la semana 24 de embarazo se relacionó directamente con el porcentaje de metilación de ADN en LINE-1 en los niños recién nacidos (beta= 0.06; IC 95%= 0.01; 0.12). Sin embargo, la relación entre estas variables no fue lineal en las niñas recién nacidas: la metilación de LINE-1 fue de 75.45% en las niñas cuyas madres estaban en el primer cuartil de exposición a BPA en la semana 24 de embarazo en comparación con aquellas en el tercer cuartil (77.03% en 3er cuartil; p-valor= 0.003). En segundo lugar, la exposición prenatal a BtP y 4OH-BP en la semana 24 de embarazo resultó en una hipometilación de las secuencias LINE-1 y Alu, respectivamente, en los niños recién nacidos [(beta= - 0.82; IC 95%= -1.28; -0.35) y (beta= -0.29; IC 95%= -0.47; -0.12), respectivamente]. Así mismo, una mayor concentración urinaria materna a PrP en la semana 24 se asoció inversamente con la metilación de LINE-1 en las niñas (beta= -0.02; IC 95%= -0.04; - 0.01). Cabe destacar que no se encontraron diferencias estadísticamente significativas en los niveles de metilación de ADN en relación a las concentraciones urinarias maternas de CDEs en las muestras del parto. Por último, el consumo materno de paracetamol en algún momento del embarazo no estuvo relacionado con la DAG de la descendencia. Aunque se encontró una asociación significativa entre a DAG ano-pene y el consumo de este fármaco en el primer trimestre en los modelos sin ajustar, esta relación desapareció cuando se tuvieron en cuenta las potenciales variables confusoras vinculadas a las variables de estudio. Conclusiones: Los hallazgos del presente estudio sugieren que la exposición prenatal a sustancias químicas o medicamentos con actividad endocrina podría influir en los marcadores de herencia epigenética, aunque no claramente sobre biomarcadores del ambiente hormonal intrauterino, como es la DAG. Los hallazgos en la cohorte NELA muestran algunos resultados diferenciados por sexo de los recién nacidos.Introduction: Environmental exposures during intrauterine development critical periods have been associated with adverse health effects. However, the biologic mechanisms explaining these effects have not been completely characterized. Therefore, there is a lack of evidence about modifiable etiological factors, such as exposure to endocrine disrupting chemicals (EDCs) or drug use during pregnancy, and the need to identify appropriate risk factors to prevent primarily the related pathologies. Studies focused on environmental exposures and their potential harmful effects on the offspring are very scarce. Therefore, the main goal of our study was to evaluate associations between maternal exposure to non-persistent endocrine chemicals and perinatal health biomarkers in a birth cohort. Material and methods: Study population were 378 mother-newborn pairs of the “Nutrition in Early Life and Asthma (NELA)” birth cohort, a study set up in the Region of Murcia (Spain) from March 2015 to April 2018. Women were followed-up during a few visits throughout the pregnancy from week 20th, obtaining data about sociodemographic characteristics, lifestyle, medication use, as well as data from clinical records. Maternal urinary concentrations of 10 EDCs (bisphenol A [BPA], bisphenol S [BPS], bisphenol F [BPF], methylparaben [MtP], butylparaben [BtP], propylparaben [PrP], 2,4-dihydroxybenzophenone [BP-1], 2-hydroxy-4-methoxybenzophenone [BP-3] and 4-hydroxybenzophenone [4OH-BP])) were determined in 24th week of pregnancy and delivery samples. EDCs concentration was measured by dispersive liquid-liquid microextraction (DLLME) and ultrahigh performance liquid chromatography with tandem mass spectrometry detection (UHPLC-MS/MS). Umbilical cord blood samples were collected at delivery. DNA methylation was quantitatively assessed by bisulphite pyrosequencing (“Pyromark Q24”, Qiagen) on LINE-1 (long interspersed nuclear elements) and Alu (short interspersed nuclear elements, SINEs) repetitive sequences. Furthermore, anogenital distance (AGD) measurements were carried out during the anthropometric examination of newborns 24-48 h after birth. Association between maternal urinary concentrations of EDCs and DNA methylation in cord blood of newborns was evaluated through linear regression models, as well as analysis of covariance (ANCOVA). In addition, relationship between maternal use of paracetamol during pregnancy and AGD measurements was also assessed through multivariate linear regression models. Moreover, influence of paracetamol use frequency during pregnancy on AGD was examined through ANCOVA models. Results: Firstly, maternal urinary concentration of BPA at 24 week of pregnancy was directly related to DNA methylation in LINE-1 of male newborns (beta= 0.06; 95% CI= 0.01; 0.12). However, the relationship between these variables was no linear in female offspring: LINE-1 methylation was 75.45% in females whose mothers were in the first quartile of BPA exposure at 24 week of pregnancy, compared to those in the third quartile (77.03% LINE-1 methylation in the 3rd quartile of BPA exposure; p-value= 0.003). Secondly, exposure to BtP and 4OH-BP at 24 week of pregnancy was negatively associated, respectively, with methylation in LINE-1 and Alu sequences in male newborns [(beta= -0.82; 95% CI= -1.28; -0.35) and (beta= -0.29; 95% CI= -0.47; -0.12), respectively]. Likewise, a high exposure to PrP at 24 week of pregnancy resulted in a hypomethylation of LINE-1 in females (beta= -0.02; 95% CI= -0.04; -0.01). No significant differences were found in levels of DNA methylation according to the maternal urinary concentrations of EDCs at delivery. Lastly, maternal paracetamol use at any time during pregnancy was no related to AGD in their offspring. Although a relationship between AGD anus-penis and paracetamol use during first trimester of pregnancy was found in unadjusted models, this association was attenuated when we considered potential confounders related to study variables. Conclusions: Our findings suggest that prenatal exposure to chemicals or drugs with endocrine activity could affect epigenetic inheritance biomarkers, although its effect on biomarkers of intrauterine hormonal environmental, such as AGD, is yet unclearly. Furthermore, the findings from the NELA birth cohort have showed some different results by sex of newborns

Are Dietary Indices Associated with Polycystic OvarySyndrome and Its Phenotypes? A Preliminary Study

©. This manuscript version is made available under the CC-BY 4.0 license http://creativecommons.org/licenses/by /4.0/ This document is the Published Manuscript version of a Published Work that appeared in final form in [Nutrients]. To access the final edited and published work see[https://doi.org/10.3390/nu13020313

Maternal urinary concentrations of bisphenol A during pregnancy are associated with global DNA methylation in cord blood of newborns in the "NELA" birth cohort.

Endocrine disrupting chemicals (EDCs) set a public health risk through disruption of normal physiological processes. The toxicoepigenetic mechanisms of developmental exposure to common EDCs, such as bisphenol A (BPA), are poorly known. The present study aimed to evaluate associations between perinatal maternal urinary concentrations of BPA, bisphenol S (BPS) and bisphenol F (BPF) and LINE-1 (long interspersed nuclear elements) and Alu (short interspersed nuclear elements, SINEs) DNA methylation levels in newborns, as surrogate markers of global DNA methylation. Data come from 318 mother-child pairs of the `Nutrition in Early Life and Asthma´ (NELA) birth cohort. Urinary bisphenol concentration was measured by dispersive liquid-liquid microextraction and ultrahigh performance liquid chromatography with tandem mass spectrometry detection. DNA methylation was quantitatively assessed by bisulphite pyrosequencing on 3 LINEs and 5 SINEs. Unadjusted linear regression analyses showed that higher concentration of maternal urinary BPA in 24th week's pregnancy was associated with an increase in LINE-1 methylation in all newborns (p = 0.01) and, particularly, in male newborns (p = 0.03). These associations remained in full adjusted models [beta = 0.09 (95 % CI = 0.03; 0.14) for all newborns; and beta = 0.10 (95 % CI = 0.03; 0.17) for males], including a non-linear association for female newborns as well (p-trend = 0.003). No associations were found between maternal concentrations of bisphenol and Alu sequences. Our results suggest that exposure to environmental levels of BPA may be associated with a modest increase in LINE-1 methylation -as a relevant marker of epigenomic stability- during human fetal development. However, any effects on global DNA methylation are likely to be small, and of uncertain biological significance