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1.
Aging Cell ; 23(8): e14194, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38808605

RESUMEN

Worldwide trends to delay childbearing have increased parental ages at birth. Older parental age may harm offspring health, but mechanisms remain unclear. Alterations in offspring DNA methylation (DNAm) patterns could play a role as aging has been associated with methylation changes in gametes of older individuals. We meta-analyzed epigenome-wide associations of parental age with offspring blood DNAm of over 9500 newborns and 2000 children (5-10 years old) from the Pregnancy and Childhood Epigenetics consortium. In newborns, we identified 33 CpG sites in 13 loci with DNAm associated with maternal age (PFDR < 0.05). Eight of these CpGs were located near/in the MTNR1B gene, coding for a melatonin receptor. Regional analysis identified them together as a differentially methylated region consisting of 9 CpGs in/near MTNR1B, at which higher DNAm was associated with greater maternal age (PFDR = 6.92 × 10-8) in newborns. In childhood blood samples, these differences in blood DNAm of MTNR1B CpGs were nominally significant (p < 0.05) and retained the same positive direction, suggesting persistence of associations. Maternal age was also positively associated with higher DNA methylation at three CpGs in RTEL1-TNFRSF6B at birth (PFDR < 0.05) and nominally in childhood (p < 0.0001). Of the remaining 10 CpGs also persistent in childhood, methylation at cg26709300 in YPEL3/BOLA2B in external data was associated with expression of ITGAL, an immune regulator. While further study is needed to establish causality, particularly due to the small effect sizes observed, our results potentially support offspring DNAm as a mechanism underlying associations of maternal age with child health.


Asunto(s)
Metilación de ADN , Edad Materna , Metilación de ADN/genética , Humanos , Femenino , Recién Nacido , Niño , Adulto , Masculino , Preescolar , Islas de CpG/genética , Embarazo
2.
Commun Biol ; 7(1): 66, 2024 01 09.
Artículo en Inglés | MEDLINE | ID: mdl-38195839

RESUMEN

Higher birth order is associated with altered risk of many disease states. Changes in placentation and exposures to in utero growth factors with successive pregnancies may impact later life disease risk via persistent DNA methylation alterations. We investigated birth order with Illumina DNA methylation array data in each of 16 birth cohorts (8164 newborns) with European, African, and Latino ancestries from the Pregnancy and Childhood Epigenetics Consortium. Meta-analyzed data demonstrated systematic DNA methylation variation in 341 CpGs (FDR adjusted P < 0.05) and 1107 regions. Forty CpGs were located within known quantitative trait loci for gene expression traits in blood, and trait enrichment analysis suggested a strong association with immune-related, transcriptional control, and blood pressure regulation phenotypes. Decreasing fertility rates worldwide with the concomitant increased proportion of first-born children highlights a potential reflection of birth order-related epigenomic states on changing disease incidence trends.


Asunto(s)
Orden de Nacimiento , Metilación de ADN , Niño , Femenino , Humanos , Recién Nacido , Embarazo , Epigénesis Genética , Epigenómica
3.
Trends Genet ; 40(1): 52-68, 2024 01.
Artículo en Inglés | MEDLINE | ID: mdl-38000919

RESUMEN

First identified in isogenic mice, metastable epialleles (MEs) are loci where the extent of DNA methylation (DNAm) is variable between individuals but correlates across tissues derived from different germ layers within a given individual. This property, termed systemic interindividual variation (SIV), is attributed to stochastic methylation establishment before germ layer differentiation. Evidence suggests that some putative human MEs are sensitive to environmental exposures in early development. In this review we introduce key concepts pertaining to human MEs, describe methods used to identify MEs in humans, and review their genomic features. We also highlight studies linking DNAm at putative human MEs to early environmental exposures and postnatal (including disease) phenotypes.


Asunto(s)
Metilación de ADN , Epigénesis Genética , Humanos , Animales , Ratones , Metilación de ADN/genética , Fenotipo , Genómica , Alelos
4.
Nat Commun ; 14(1): 5200, 2023 08 25.
Artículo en Inglés | MEDLINE | ID: mdl-37626025

RESUMEN

Human height is strongly influenced by genetics but the contribution of modifiable epigenetic factors is under-explored, particularly in low and middle-income countries (LMIC). We investigate links between blood DNA methylation and child height in four LMIC cohorts (n = 1927) and identify a robust association at three CpGs in the suppressor of cytokine signaling 3 (SOCS3) gene which replicates in a high-income country cohort (n = 879). SOCS3 methylation (SOCS3m)-height associations are independent of genetic effects. Mendelian randomization analysis confirms a causal effect of SOCS3m on height. In longitudinal analysis, SOCS3m explains a maximum 9.5% of height variance in mid-childhood while the variance explained by height polygenic risk score increases from birth to 21 years. Children's SOCS3m is associated with prenatal maternal folate and socio-economic status. In-vitro characterization confirms a regulatory effect of SOCS3m on gene expression. Our findings suggest epigenetic modifications may play an important role in driving child height in LMIC.


Asunto(s)
Metilación de ADN , Proteínas Supresoras de la Señalización de Citocinas , Femenino , Embarazo , Humanos , Niño , Metilación de ADN/genética , Proteínas Supresoras de la Señalización de Citocinas/genética , Epigénesis Genética , Epigenómica , Citocinas , Proteína 3 Supresora de la Señalización de Citocinas/genética
5.
Sci Transl Med ; 15(705): eadg1659, 2023 07 19.
Artículo en Inglés | MEDLINE | ID: mdl-37467315

RESUMEN

Increasing evidence points toward epigenetic variants as a risk factor for developing obesity. We analyzed DNA methylation of the POMC (pro-opiomelanocortin) gene, which is pivotal for satiety regulation. We identified sex-specific and nongenetically determined POMC hypermethylation associated with a 1.4-fold (confidence interval, 1.03 to 2.04) increased individual risk of developing obesity. To investigate the early embryonic establishment of POMC methylation states, we established a human embryonic stem cell (hESC) model. Here, hESCs (WA01) were transferred into a naïve state, which was associated with a reduction of DNA methylation. Naïve hESCs were differentiated via a formative state into POMC-expressing hypothalamic neurons, which was accompanied by re-establishment of DNA methylation patterning. We observed that reduced POMC gene expression was associated with increased POMC methylation in POMC-expressing neurons. On the basis of these findings, we treated POMC-hypermethylated obese individuals (n = 5) with an MC4R agonist and observed a body weight reduction of 4.66 ± 2.16% (means ± SD) over a mean treatment duration of 38.4 ± 26.0 weeks. In summary, we identified an epigenetic obesity risk variant at the POMC gene fulfilling the criteria for a metastable epiallele established in early embryonic development that may be addressable by MC4R agonist treatment to reduce body weight.


Asunto(s)
Obesidad , Proopiomelanocortina , Masculino , Embarazo , Femenino , Humanos , Proopiomelanocortina/genética , Proopiomelanocortina/metabolismo , Obesidad/genética , Obesidad/metabolismo , Peso Corporal/fisiología , Metilación de ADN/genética , Factores de Riesgo , Receptor de Melanocortina Tipo 4/genética , Receptor de Melanocortina Tipo 4/metabolismo
6.
Front Cell Dev Biol ; 11: 1212199, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37484911

RESUMEN

DNA methylation is the most commonly studied epigenetic mark in humans, as it is well recognised as a stable, heritable mark that can affect genome function and influence gene expression. Somatic DNA methylation patterns that can persist throughout life are established shortly after fertilisation when the majority of epigenetic marks, including DNA methylation, are erased from the pre-implantation embryo. Therefore, the period around conception is potentially critical for influencing DNA methylation, including methylation at imprinted alleles and metastable epialleles (MEs), loci where methylation varies between individuals but is correlated across tissues. Exposures before and during conception can affect pregnancy outcomes and health throughout life. Retrospective studies of the survivors of famines, such as those exposed to the Dutch Hunger Winter of 1944-45, have linked exposures around conception to later disease outcomes, some of which correlate with DNA methylation changes at certain genes. Animal models have shown more directly that DNA methylation can be affected by dietary supplements that act as cofactors in one-carbon metabolism, and in humans, methylation at birth has been associated with peri-conceptional micronutrient supplementation. However, directly showing a role of micronutrients in shaping the epigenome has proven difficult. Recently, the placenta, a tissue with a unique hypomethylated methylome, has been shown to possess great inter-individual variability, which we highlight as a promising target tissue for studying MEs and mixed environmental exposures. The placenta has a critical role shaping the health of the fetus. Placenta-associated pregnancy complications, such as preeclampsia and intrauterine growth restriction, are all associated with aberrant patterns of DNA methylation and expression which are only now being linked to disease risk later in life.

7.
Nucleic Acids Res ; 50(12): 6735-6752, 2022 07 08.
Artículo en Inglés | MEDLINE | ID: mdl-35713545

RESUMEN

We analysed DNA methylation data from 30 datasets comprising 3474 individuals, 19 tissues and 8 ethnicities at CpGs covered by the Illumina450K array. We identified 4143 hypervariable CpGs ('hvCpGs') with methylation in the top 5% most variable sites across multiple tissues and ethnicities. hvCpG methylation was influenced but not determined by genetic variation, and was not linked to probe reliability, epigenetic drift, age, sex or cell heterogeneity effects. hvCpG methylation tended to covary across tissues derived from different germ-layers and hvCpGs were enriched for proximity to ERV1 and ERVK retrovirus elements. hvCpGs were also enriched for loci previously associated with periconceptional environment, parent-of-origin-specific methylation, and distinctive methylation signatures in monozygotic twins. Together, these properties position hvCpGs as strong candidates for studying how stochastic and/or environmentally influenced DNA methylation states which are established in the early embryo and maintained stably thereafter can influence life-long health and disease.


Asunto(s)
Metilación de ADN , Embrión de Mamíferos , Humanos , Metilación de ADN/genética , Reproducibilidad de los Resultados , Embrión de Mamíferos/metabolismo , Islas de CpG , Etnicidad
8.
Elife ; 112022 02 21.
Artículo en Inglés | MEDLINE | ID: mdl-35188105

RESUMEN

In humans, DNA methylation marks inherited from gametes are largely erased following fertilisation, prior to construction of the embryonic methylome. Exploiting a natural experiment of seasonal variation including changes in diet and nutritional status in rural Gambia, we analysed three datasets covering two independent child cohorts and identified 259 CpGs showing consistent associations between season of conception (SoC) and DNA methylation. SoC effects were most apparent in early infancy, with evidence of attenuation by mid-childhood. SoC-associated CpGs were enriched for metastable epialleles, parent-of-origin-specific methylation and germline differentially methylated regions, supporting a periconceptional environmental influence. Many SoC-associated CpGs overlapped enhancers or sites of active transcription in H1 embryonic stem cells and fetal tissues. Half were influenced but not determined by measured genetic variants that were independent of SoC. Environmental 'hotspots' providing a record of environmental influence at periconception constitute a valuable resource for investigating epigenetic mechanisms linking early exposures to lifelong health and disease.


Asunto(s)
Metilación de ADN , Epigenoma , Niño , Islas de CpG , Embrión de Mamíferos , Epigénesis Genética , Fertilización , Humanos
9.
Clin Epigenetics ; 14(1): 6, 2022 01 09.
Artículo en Inglés | MEDLINE | ID: mdl-35000590

RESUMEN

BACKGROUND: The prevalence of cardiometabolic disease (CMD) is rising globally, with environmentally induced epigenetic changes suggested to play a role. Few studies have investigated epigenetic associations with CMD risk factors in children from low- and middle-income countries. We sought to identify associations between DNA methylation (DNAm) and CMD risk factors in children from India and The Gambia. RESULTS: Using the Illumina Infinium HumanMethylation 850 K Beadchip array, we interrogated DNAm in 293 Gambian (7-9 years) and 698 Indian (5-7 years) children. We identified differentially methylated CpGs (dmCpGs) associated with systolic blood pressure, fasting insulin, triglycerides and LDL-Cholesterol in the Gambian children; and with insulin sensitivity, insulinogenic index and HDL-Cholesterol in the Indian children. There was no overlap of the dmCpGs between the cohorts. Meta-analysis identified dmCpGs associated with insulin secretion and pulse pressure that were different from cohort-specific dmCpGs. Several differentially methylated regions were associated with diastolic blood pressure, insulin sensitivity and fasting glucose, but these did not overlap with the dmCpGs. We identified significant cis-methQTLs at three LDL-Cholesterol-associated dmCpGs in Gambians; however, methylation did not mediate genotype effects on the CMD outcomes. CONCLUSION: This study identified cardiometabolic biomarkers associated with differential DNAm in Indian and Gambian children. Most associations were cohort specific, potentially reflecting environmental and ethnic differences.


Asunto(s)
Biomarcadores , Factores de Riesgo Cardiometabólico , Metilación de ADN/genética , Epigénesis Genética , Predisposición Genética a la Enfermedad , Síndrome Metabólico/epidemiología , Síndrome Metabólico/genética , Niño , Preescolar , Estudios de Cohortes , Femenino , Gambia/epidemiología , Humanos , India/epidemiología , Masculino , Prevalencia
10.
Sci Adv ; 7(45): eabj1561, 2021 Nov 05.
Artículo en Inglés | MEDLINE | ID: mdl-34739318

RESUMEN

PAX8 is a key thyroid transcription factor implicated in thyroid gland differentiation and function, and PAX8 gene methylation is reported to be sensitive to the periconceptional environment. Using a novel recall-by-epigenotype study in Gambian children, we found that PAX8 hypomethylation at age 2 years is associated with a 21% increase in thyroid volume and an increase in free thyroxine (T4) at 5 to 8 years, the latter equivalent to 8.4% of the normal range. Free T4 was associated with a decrease in DXA-derived body fat and bone mineral density. Furthermore, offspring PAX8 methylation was associated with periconceptional maternal nutrition, and methylation variability was influenced by genotype, suggesting that sensitivity to environmental exposures may be under partial genetic control. Together, our results demonstrate a possible link between early environment, PAX8 gene methylation and thyroid gland development and function, with potential implications for early embryonic programming of thyroid-related health and disease.

11.
J Nutr ; 151(7): 1854-1878, 2021 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-33982105

RESUMEN

BACKGROUND: Many nutrients have powerful immunomodulatory actions with the potential to alter susceptibility to coronavirus disease 2019 (COVID-19) infection, progression to symptoms, likelihood of severe disease, and survival. OBJECTIVE: The aim was to review the latest evidence on how malnutrition across all its forms (under- and overnutrition and micronutrient status) may influence both susceptibility to, and progression of, COVID-19. METHODS: We synthesized information on 13 nutrition-related components and their potential interactions with COVID-19: overweight, obesity, and diabetes; protein-energy malnutrition; anemia; vitamins A, C, D, and E; PUFAs; iron; selenium; zinc; antioxidants; and nutritional support. For each section we provide: 1) a landscape review of pertinent material; 2) a systematic search of the literature in PubMed and EMBASE databases, including a wide range of preprint servers; and 3) a screen of 6 clinical trial registries. All original research was considered, without restriction to study design, and included if it covered: 1) severe acute respiratory syndrome coronavirus (CoV) 2 (SARS-CoV-2), Middle East respiratory syndrome CoV (MERS-CoV), or SARS-CoV viruses and 2) disease susceptibility or 3) disease progression, and 4) the nutritional component of interest. Searches took place between 16 May and 11 August 2020. RESULTS: Across the 13 searches, 2732 articles from PubMed and EMBASE, 4164 articles from the preprint servers, and 433 trials were returned. In the final narrative synthesis, we include 22 published articles, 38 preprint articles, and 79 trials. CONCLUSIONS: Currently there is limited evidence that high-dose supplements of micronutrients will either prevent severe disease or speed up recovery. However, results of clinical trials are eagerly awaited. Given the known impacts of all forms of malnutrition on the immune system, public health strategies to reduce micronutrient deficiencies and undernutrition remain of critical importance. Furthermore, there is strong evidence that prevention of obesity and type 2 diabetes will reduce the risk of serious COVID-19 outcomes. This review is registered at PROSPERO as CRD42020186194.


Asunto(s)
Anemia/epidemiología , COVID-19/epidemiología , COVID-19/inmunología , Diabetes Mellitus/epidemiología , Estado Nutricional , Obesidad/epidemiología , Desnutrición Proteico-Calórica/epidemiología , Antioxidantes/metabolismo , COVID-19/prevención & control , COVID-19/terapia , Comorbilidad , Suplementos Dietéticos , Progresión de la Enfermedad , Ácidos Grasos Omega-3/inmunología , Ácidos Grasos Omega-6/inmunología , Humanos , Hierro/inmunología , Apoyo Nutricional , SARS-CoV-2 , Selenio/inmunología , Índice de Severidad de la Enfermedad , Vitaminas/inmunología , Zinc/inmunología
12.
Am J Clin Nutr ; 112(4): 1099-1113, 2020 10 01.
Artículo en Inglés | MEDLINE | ID: mdl-32889533

RESUMEN

BACKGROUND: Maternal nutrition in pregnancy has been linked to offspring health in early and later life, with changes to DNA methylation (DNAm) proposed as a mediating mechanism. OBJECTIVE: We investigated intervention-associated DNAm changes in children whose mothers participated in 2 randomized controlled trials of micronutrient supplementation before and during pregnancy, as part of the EMPHASIS (Epigenetic Mechanisms linking Preconceptional nutrition and Health Assessed in India and sub-Saharan Africa) study (ISRCTN14266771). DESIGN: We conducted epigenome-wide association studies with blood samples from Indian (n = 698) and Gambian (n = 293) children using the Illumina EPIC array and a targeted study of selected loci not on the array. The Indian micronutrient intervention was food based, whereas the Gambian intervention was a micronutrient tablet. RESULTS: We identified 6 differentially methylated CpGs in Gambians [2.5-5.0% reduction in intervention group, all false discovery rate (FDR) <5%], the majority mapping to ESM1, which also represented a strong signal in regional analysis. One CpG passed FDR <5% in the Indian cohort, but overall effect sizes were small (<1%) and did not have the characteristics of a robust signature. We also found strong evidence for enrichment of metastable epialleles among subthreshold signals in the Gambian analysis. This supports the notion that multiple methylation loci are influenced by micronutrient supplementation in the early embryo. CONCLUSIONS: Maternal preconceptional and pregnancy micronutrient supplementation may alter DNAm in children measured at 7-9 y. Multiple factors, including differences between the nature of the intervention, participants, and settings, are likely to have contributed to the lack of replication in the Indian cohort. Potential links to phenotypic outcomes will be explored in the next stage of the EMPHASIS study.


Asunto(s)
Metilación de ADN , Fenómenos Fisiologicos Nutricionales Maternos , Micronutrientes/administración & dosificación , Adulto , Niño , Preescolar , Femenino , Interacción Gen-Ambiente , Humanos , Masculino , Proteínas de Neoplasias/genética , Embarazo , Proteoglicanos/genética , Sitios de Carácter Cuantitativo , Ensayos Clínicos Controlados Aleatorios como Asunto
13.
Sci Rep ; 10(1): 9675, 2020 06 15.
Artículo en Inglés | MEDLINE | ID: mdl-32541825

RESUMEN

Early life exposures are important predictors of adult disease risk. Although the underlying mechanisms are largely unknown, telomere maintenance may be involved. This study investigated the relationship between seasonal differences in parental exposures at time of conception and leukocyte telomere length (LTL) in their offspring. LTL was measured in two cohorts of children aged 2 yrs (N = 487) and 7-9 yrs (N = 218). The association between date of conception and LTL was examined using Fourier regression models, adjusted for age, sex, leukocyte cell composition, and other potential confounders. We observed an effect of season in the older children in all models [likelihood ratio test (LRT) χ²2 = 7.1, p = 0.03; fully adjusted model]. LTL was greatest in children conceived in September (in the rainy season), and smallest in those conceived in March (in the dry season), with an effect size (LTL peak-nadir) of 0.60 z-scores. No effect of season was evident in the younger children (LRT χ²2 = 0.87, p = 0.65). The different results obtained for the two cohorts may reflect a delayed effect of season of conception on postnatal telomere maintenance. Alternatively, they may be explained by unmeasured differences in early life exposures, or the increased telomere attrition rate during infancy.


Asunto(s)
Leucocitos/metabolismo , Acortamiento del Telómero , Telómero/metabolismo , Niño , Preescolar , Estudios Transversales , Femenino , Fertilización , Gambia , Humanos , Masculino , Análisis de Regresión , Estaciones del Año
14.
Nestle Nutr Inst Workshop Ser ; 93: 145-152, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-31991428

RESUMEN

The link between poor maternal nutrition and suboptimal outcomes in offspring is well established, but underlying mechanisms are not well understood. Modifications to the offspring epigenome are a plausible mechanism for the transmission of intergenerational signals that could extend to effects of paternal nutrition mediated by epigenetic modifications in sperm. The epigenome is extensively remodeled in the early embryo. Attention has therefore focused on the periconceptional period as a time when differences in parental nutrition might influence the establishment of epigenetic marks in offspring. So-called "natural experiments" in The Gambia and elsewhere have highlighted loci that may be especially sensitive to periconceptional nutrition, and some are associated with health-related outcomes in later life. There is speculation that some epigenetic signals could be transmitted across multiple generations, although this would require epigenetic marks to evade epigenetic reprogramming events at conception and in primordial germ cells, and evidence for this is lacking in humans. Effects on child development spanning one or more generations could impose an intergenerational "brake" on a child's growth potential, limiting, for example, the rate at which populations can escape from stunting.


Asunto(s)
Desarrollo Infantil , Epigénesis Genética/genética , Preescolar , Metilación de ADN , Femenino , Gambia , Abuelos , Humanos , Lactante , Recién Nacido , Masculino , Fenómenos Fisiologicos Nutricionales Maternos/genética , Fenómenos Fisiológicos de la Nutrición , Herencia Paterna/genética , Embarazo , Efectos Tardíos de la Exposición Prenatal/genética
15.
PLoS Med ; 16(8): e1002870, 2019 08.
Artículo en Inglés | MEDLINE | ID: mdl-31408467

RESUMEN

BACKGROUND: Infant DNA methylation profiles are associated with their mother's periconceptional nutritional status. DNA methylation relies on nutritional inputs for one-carbon metabolic pathways, including the efficient recycling of homocysteine. This randomised controlled trial in nonpregnant women in rural Gambia tests the efficacy of a novel nutritional supplement designed to improve one-carbon-related nutrient status by reducing plasma homocysteine, and assesses its potential future use in preconception trials. METHODS AND FINDINGS: We designed a novel drink powder based on determinants of plasma homocysteine in the target population and tested it in a three-arm, randomised, controlled trial. Nonpregnant women aged between 18 and 45 from the West Kiang region of The Gambia were randomised in a 1:1:1 allocation to 12 weeks daily supplementation of either (a) a novel drink powder (4 g betaine, 800 µg folic acid, 5.2 µg vitamin B12, and 2.8 mg vitamin B2), (b) a widely used multiple micronutrient tablet (United Nations Multiple Micronutrient Preparation [UNIMMAP]) containing 15 micronutrients, or (c) no intervention. The trial was conducted between March and July 2018. Supplementation was observed daily. Fasted venepuncture samples were collected at baseline, midline (week 5), and endline (week 12) to measure plasma homocysteine. We used linear regression models to determine the difference in homocysteine between pairs of trial arms at midline and endline, adjusted for baseline homocysteine, age, and body mass index (BMI). Blood pressure and pulse were measured as secondary outcomes. Two hundred and ninety-eight eligible women were enrolled and randomised. Compliance was >97.8% for both interventions. At endline (our primary endpoint), the drink powder and UNIMMAP reduced mean plasma homocysteine by 23.6% (-29.5 to -17.1) and 15.5% (-21.2 to -9.4), respectively (both p < 0.001), compared with the controls. Compared with UNIMMAP, the drink powder reduced mean homocysteine by 8.8% (-15.8 to -1.2; p = 0.025). The effects were stronger at midline. There was no effect of either intervention on blood pressure or pulse compared with the control at endline. Self-reported adverse events (AEs) were similar in both intervention arms. There were two serious AEs reported over the trial duration, both in the drink powder arm, but judged to be unrelated to the intervention. Limitations of the study include the use of a single targeted metabolic outcome, homocysteine. CONCLUSIONS: The trial confirms that dietary supplements can influence metabolic pathways that we have shown in previous studies to predict offspring DNA methylation. Both supplements reduced homocysteine effectively and remain potential candidates for future epigenetic trials in pregnancy in rural Gambia. TRIAL REGISTRATION: Clinicaltrials.gov Reference NCT03431597.


Asunto(s)
Suplementos Dietéticos , Homocisteína/sangre , Adolescente , Adulto , Betaína/administración & dosificación , Betaína/uso terapéutico , Femenino , Ácido Fólico/administración & dosificación , Ácido Fólico/uso terapéutico , Gambia , Homocisteína/antagonistas & inhibidores , Humanos , Persona de Mediana Edad , Estado Nutricional , Riboflavina/administración & dosificación , Riboflavina/uso terapéutico , Vitamina B 12/administración & dosificación , Vitamina B 12/uso terapéutico , Adulto Joven
16.
Genome Biol ; 20(1): 105, 2019 06 03.
Artículo en Inglés | MEDLINE | ID: mdl-31155008

RESUMEN

BACKGROUND: DNA methylation is thought to be an important determinant of human phenotypic variation, but its inherent cell type specificity has impeded progress on this question. At exceptional genomic regions, interindividual variation in DNA methylation occurs systemically. Like genetic variants, systemic interindividual epigenetic variants are stable, can influence phenotype, and can be assessed in any easily biopsiable DNA sample. We describe an unbiased screen for human genomic regions at which interindividual variation in DNA methylation is not tissue-specific. RESULTS: For each of 10 donors from the NIH Genotype-Tissue Expression (GTEx) program, CpG methylation is measured by deep whole-genome bisulfite sequencing of genomic DNA from tissues representing the three germ layer lineages: thyroid (endoderm), heart (mesoderm), and brain (ectoderm). We develop a computational algorithm to identify genomic regions at which interindividual variation in DNA methylation is consistent across all three lineages. This approach identifies 9926 correlated regions of systemic interindividual variation (CoRSIVs). These regions, comprising just 0.1% of the human genome, are inter-correlated over long genomic distances, associated with transposable elements and subtelomeric regions, conserved across diverse human ethnic groups, sensitive to periconceptional environment, and associated with genes implicated in a broad range of human disorders and phenotypes. CoRSIV methylation in one tissue can predict expression of associated genes in other tissues. CONCLUSIONS: In addition to charting a previously unexplored molecular level of human individuality, this atlas of human CoRSIVs provides a resource for future population-based investigations into how interindividual epigenetic variation modulates risk of disease.


Asunto(s)
Metilación de ADN , Epigénesis Genética , Genoma Humano , Anciano , Encéfalo/metabolismo , Estudios de Casos y Controles , Niño , Enfermedad/genética , Femenino , Gambia , Variación Genética , Humanos , Masculino , Persona de Mediana Edad , Miocardio/metabolismo , Embarazo , Fenómenos Fisiologicos de la Nutrición Prenatal , Estaciones del Año , Glándula Tiroides/metabolismo
17.
Sci Adv ; 4(7): eaat2624, 2018 07.
Artículo en Inglés | MEDLINE | ID: mdl-30009262

RESUMEN

The molecular mechanisms responsible for the developmental origins of later disease are currently unknown. We previously demonstrated that women's periconceptional nutrition predicts their offspring's DNA methylation at metastable epialleles (MEs). We present a genome-wide screen yielding 687 MEs and track their trajectories across nine developmental stages in human in vitro fertilization embryos. MEs exhibit highly unusual methylation dynamics across the implantation-gastrulation transition, producing a large excess of intermediate methylation states, suggesting the potential for differential programming in response to external signals. Using a natural experiment in rural Gambia, we show that genomic regions sensitive to season of conception are highly enriched for MEs and show similar atypical methylation patterns. MEs are enriched for proximal enhancers and transcription start sites and are influenced by genotype. Together, these observations position MEs as distinctive epigenomic features programmed in the early embryo, sensitive to genetic and periconceptional environment, and with the potential to influence phenotype.


Asunto(s)
Metilación de ADN , Embrión de Mamíferos/metabolismo , Adulto , Sitios de Unión , Preescolar , Islas de CpG , Desarrollo Embrionario , Femenino , Fertilización In Vitro , Humanos , Intestino Delgado/metabolismo , Hígado/metabolismo , Masculino , Polimorfismo de Nucleótido Simple , Sitios de Carácter Cuantitativo , Secuenciación del Exoma
18.
Genome Biol ; 19(1): 2, 2018 01 09.
Artículo en Inglés | MEDLINE | ID: mdl-29310692

RESUMEN

BACKGROUND: Monozygotic twins have long been studied to estimate heritability and explore epigenetic influences on phenotypic variation. The phenotypic and epigenetic similarities of monozygotic twins have been assumed to be largely due to their genetic identity. RESULTS: Here, by analyzing data from a genome-scale study of DNA methylation in monozygotic and dizygotic twins, we identified genomic regions at which the epigenetic similarity of monozygotic twins is substantially greater than can be explained by their genetic identity. This "epigenetic supersimilarity" apparently results from locus-specific establishment of epigenotype prior to embryo cleavage during twinning. Epigenetically supersimilar loci exhibit systemic interindividual epigenetic variation and plasticity to periconceptional environment and are enriched in sub-telomeric regions. In case-control studies nested in a prospective cohort, blood DNA methylation at these loci years before diagnosis is associated with risk of developing several types of cancer. CONCLUSIONS: These results establish a link between early embryonic epigenetic development and adult disease. More broadly, epigenetic supersimilarity is a previously unrecognized phenomenon that may contribute to the phenotypic similarity of monozygotic twins.


Asunto(s)
Epigénesis Genética , Gemelos Monocigóticos/genética , Islas de CpG , ADN/sangre , Metilación de ADN , Genoma Humano , Humanos , Modelos Genéticos , Neoplasias/genética , Gemelos Dicigóticos
19.
Genet Epidemiol ; 42(1): 20-33, 2018 02.
Artículo en Inglés | MEDLINE | ID: mdl-29034560

RESUMEN

Epigenome-wide association studies (EWAS) are designed to characterise population-level epigenetic differences across the genome and link them to disease. Most commonly, they assess DNA-methylation status at cytosine-guanine dinucleotide (CpG) sites, using platforms such as the Illumina 450k array that profile a subset of CpGs genome wide. An important challenge in the context of EWAS is determining a significance threshold for declaring a CpG site as differentially methylated, taking multiple testing into account. We used a permutation method to estimate a significance threshold specifically for the 450k array and a simulation extrapolation approach to estimate a genome-wide threshold. These methods were applied to five different EWAS datasets derived from a variety of populations and tissue types. We obtained an estimate of α=2.4×10-7 for the 450k array, and a genome-wide estimate of α=3.6×10-8. We further demonstrate the importance of these results by showing that previously recommended sample sizes for EWAS should be adjusted upwards, requiring samples between ∼10% and ∼20% larger in order to maintain type-1 errors at the desired level.


Asunto(s)
Islas de CpG/genética , Metilación de ADN , Epigénesis Genética/genética , Genoma Humano/genética , Estudio de Asociación del Genoma Completo/métodos , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Trastorno Bipolar/genética , Neoplasias Colorrectales/genética , Conjuntos de Datos como Asunto , Depresión/genética , Humanos , Lactante , Persona de Mediana Edad , Modelos Genéticos , Tamaño de la Muestra , Adulto Joven
20.
FASEB J ; 31(11): 4928-4934, 2017 11.
Artículo en Inglés | MEDLINE | ID: mdl-28778976

RESUMEN

The prenatal environment can alter an individual's developmental trajectory with long-lasting effects on health. Animal models demonstrate that the impact of the early life environment extends to subsequent generations, but there is a paucity of data from human populations on intergenerational transmission of environmentally induced phenotypes. Here we investigated the association of parental exposure to energy and nutrient restriction in utero on their children's growth in rural Gambia. In a Gambian cohort with infants born between 1972 and 2011, we used multiple regression to test whether parental season of birth predicted offspring birth weight (n = 2097) or length (n = 1172), height-for-age z score (HAZ), weight-for-height z score (WHZ), and weight-for-age z score (WAZ) at 2 yr of age (n = 923). We found that maternal exposure to seasonal energy restriction in utero was associated with reduced offspring birth length (crude:-4.2 mm, P = 0.005; adjusted: -4.0 mm, P = 0.02). In contrast, paternal birth season predicted offspring HAZ at 24 mo (crude: -0.21, P = 0.005; adjusted: -0.22, P = 0.004) but had no discernible impact at birth. Our results indicate that periods of nutritional restriction in a parent's fetal life can have intergenerational consequences in human populations. Fetal growth appears to be under matriline influence, and postnatal growth appears to be under patriline intergenerational influences.-Eriksen, K. G., Radford, E. J., Silver, M. J., Fulford, A. J. C., Wegmüller, R., Prentice, A. M. Influence of intergenerational in utero parental energy and nutrient restriction on offspring growth in rural Gambia.


Asunto(s)
Peso al Nacer , Restricción Calórica , Exposición Materna/efectos adversos , Efectos Tardíos de la Exposición Prenatal/epidemiología , Efectos Tardíos de la Exposición Prenatal/fisiopatología , Femenino , Gambia/epidemiología , Humanos , Masculino , Embarazo , Efectos Tardíos de la Exposición Prenatal/patología
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