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Berntzen BJ, Palviainen T, Silventoinen K, Pietiläinen KH, Kaprio J. Polygenic risk of obesity and BMI trajectories over 36 years: A longitudinal study of adult Finnish twins. Obesity (Silver Spring) 2023; 31:3086-3094. [PMID: 37987187 PMCID: PMC10947257 DOI: 10.1002/oby.23906] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Revised: 08/04/2023] [Accepted: 08/06/2023] [Indexed: 11/22/2023]
Abstract
OBJECTIVE This study investigated 36-year BMI trajectories in twins whose BMI in young adulthood was below, within, or above their genetically predicted BMI, with a focus on twin pairs with large intrapair BMI differences (within-pair ΔBMI ≥ 3 kg/m2 ). METHODS Together, 3227 like-sexed twin pairs (34% monozygotic) were examined at age ~30 years in 1975 and followed up in 1981, 1990, and 2011. An individual's observed BMI in 1975 was considered within (±2.0), below (<-2.0), or above (>+2.0) genetically predicted BMI, measured by a polygenic risk score of 996,919 single nucleotide polymorphisms. RESULTS In monozygotic and dizygotic twin pairs with large intrapair BMI differences, the co-twin with a higher observed BMI in 1975 deviated above predicted BMI more frequently (~2/3) than the co-twin with a lower BMI deviated below prediction (~1/3). Individuals below, within, and above prediction in 1975 reached, respectively, normal weight, overweight, and obesity by 2011, with a mean BMI increase of 4.5 (95% CI: 4.3-4.8). CONCLUSIONS Categorizing BMI as below, within, or above polygenic risk score-predicted BMI helps identifying individuals who have been resistant or susceptible to weight gain. This may provide new insights into determinants and consequences of obesity.
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Affiliation(s)
- Bram J. Berntzen
- Institute for Molecular Medicine Finland (FIMM)University of HelsinkiHelsinkiFinland
- Obesity Research Unit, Research Program for Clinical and Molecular Metabolism, Faculty of MedicineUniversity of HelsinkiHelsinkiFinland
| | - Teemu Palviainen
- Institute for Molecular Medicine Finland (FIMM)University of HelsinkiHelsinkiFinland
| | - Karri Silventoinen
- Faculty of Social Sciences, Population Research UnitUniversity of HelsinkiHelsinkiFinland
| | - Kirsi H. Pietiläinen
- Obesity Research Unit, Research Program for Clinical and Molecular Metabolism, Faculty of MedicineUniversity of HelsinkiHelsinkiFinland
- HealthyWeightHub, Endocrinology, Abdominal CenterHelsinki University Hospital and University of HelsinkiHelsinkiFinland
| | - Jaakko Kaprio
- Institute for Molecular Medicine Finland (FIMM)University of HelsinkiHelsinkiFinland
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Abstract
The East Flanders Prospective Twin Survey (EFPTS) is a registry of multiple births in the province of East Flanders, Belgium. Since its start in 1964, over 10,000 twin-pairs have been registered. EFPTS has several unique features: it is population-based and prospective, with the possibility of long-term follow-up; the twins (and higher order multiple births) are recruited at birth; basic perinatal data are recorded; chorion type and zygosity are established; since 1969, placental biopsies have been taken and frozen at -20°C for future research. Since its origin, the EFPTS has included placental data and allows differentiation of three subtypes of monozygotic twins based on the time of the initial zygotic division: the dichorionic-diamniotic pairs (early, with splitting before the fourth day after fertilization), the monochorionic-diamniotic pairs (intermediate, splitting between the fourth- and the seventh-day postfertilization) and the monochorionic-monoamniotic pairs (late, splitting after the eighth day postfertilization). Studies can be initiated taking into account primary biases, those originating 'in utero'. Such studies could throw new light on the consequences of early embryological events and the gene-environment interactions as far as periconceptional and intrauterine environment are concerned.
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Kaufman J, Montalvo-Ortiz JL, Holbrook H, O’Loughlin K, Orr C, Kearney C, Yang BZ, Wang T, Zhao H, Althoff R, Garavan H, Gelernter J, Hudziak J. Adverse Childhood Experiences, Epigenetic Measures, and Obesity in Youth. J Pediatr 2018; 202:150-156.e3. [PMID: 30177354 PMCID: PMC6513669 DOI: 10.1016/j.jpeds.2018.06.051] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/25/2018] [Revised: 05/14/2018] [Accepted: 06/14/2018] [Indexed: 12/11/2022]
Abstract
OBJECTIVE To determine if measures of adverse childhood experiences and DNA methylation relate to indices of obesity in youth. STUDY DESIGN Participants were derived from a cohort of 321 8 to 15-year-old children recruited for an investigation examining risk and resilience and psychiatric outcomes in maltreated children. Assessments of obesity were collected as an add-on for a subset of 234 participants (56% female; 52% maltreated). Illumina arrays were used to examine whole genome epigenetic predictors of obesity in saliva DNA. For analytic purposes, the cohort analyzed in the first batch comprised the discovery sample (n = 160), and the cohort analyzed in the second batch the replication sample (n = 74). RESULTS After controlling for race, sex, age, cell heterogeneity, 3 principal components, and whole genome testing, 10 methylation sites were found to interact with adverse childhood experiences to predict cross-sectional measures of body mass index, and an additional 6 sites were found to exert a main effect in predicting body mass index (P < 5.0 × 10-7, all comparisons). Eight of the methylation sites were in genes previously associated with obesity risk (eg, PCK2, CxCl10, BCAT1, HID1, PRDM16, MADD, PXDN, GALE), with several of the findings from the discovery data set replicated in the second cohort. CONCLUSIONS This study lays the groundwork for future longitudinal studies to elucidate these mechanisms further and identify novel interventions to alleviate the health burdens associated with early adversity.
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Affiliation(s)
- Joan Kaufman
- Center for Child and Family Traumatic Stress, Kennedy Krieger Institute, Baltimore, MD; Department of Psychiatry and Behavioral Sciences, Johns Hopkins School of Medicine, Baltimore, MD; Department of Psychiatry, Yale University, New Haven, CT.
| | | | - Hannah Holbrook
- Vermont Center for Children, Youth, and Families, Department of Psychiatry, University of Vermont, Burlington, VT
| | - Kerry O’Loughlin
- Vermont Center for Children, Youth, and Families, Department of Psychiatry, University of Vermont, Burlington, VT
| | - Catherine Orr
- Vermont Center for Children, Youth, and Families, Department of Psychiatry, University of Vermont, Burlington, VT
| | - Catherine Kearney
- Center for Child and Family Traumatic Stress, Kennedy Krieger Institute
| | - Bao-Zhu Yang
- Department of Psychiatry, Yale University, New Haven, CT
| | - Tao Wang
- Department of Biostatistics, Yale University, New Haven, CT,Department of Bioinformatics and Biostatistics, Shanghai Jiao Tong University, Shanghai, China
| | - Hongyu Zhao
- Department of Biostatistics, Yale University, New Haven, CT
| | - Robert Althoff
- Vermont Center for Children, Youth, and Families, Department of Psychiatry, University of Vermont, Burlington, VT
| | - Hugh Garavan
- Vermont Center for Children, Youth, and Families, Department of Psychiatry, University of Vermont, Burlington, VT
| | - Joel Gelernter
- Department of Psychiatry, Yale University, New Haven, CT,Veterans Administration, West Haven, CT
| | - James Hudziak
- Vermont Center for Children, Youth, and Families, Department of Psychiatry, University of Vermont, Burlington, VT
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4
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Nishitani S, Parets SE, Haas BW, Smith AK. DNA methylation analysis from saliva samples for epidemiological studies. Epigenetics 2018; 13:352-362. [PMID: 29912612 DOI: 10.1080/15592294.2018.1461295] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022] Open
Abstract
Saliva is a non-invasive, easily accessible tissue, which is regularly collected in large epidemiological studies to examine genetic questions. Recently, it is becoming more common to use saliva to assess DNA methylation. However, DNA extracted from saliva is a mixture of both bacterial and human DNA derived from epithelial and immune cells in the mouth. Thus, there are unique challenges to using salivary DNA in methylation studies that can influence data quality. This study assesses: (1) quantification of human DNA after extraction; (2) delineation of human and bacterial DNA; (3) bisulfite conversion (BSC); (4) quantification of BSC DNA; (5) PCR amplification of BSC DNA from saliva and; (6) quantitation of DNA methylation with a targeted assay. The framework proposed will allow saliva samples to be more widely used in targeted epigenetic studies.
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Affiliation(s)
- Shota Nishitani
- a Department of Gynecology and Obstetrics , Emory University School of Medicine , Atlanta , GA , USA.,b Department of Psychiatry and Behavioral Sciences , Emory University School of Medicine , Atlanta , GA , USA
| | - Sasha E Parets
- b Department of Psychiatry and Behavioral Sciences , Emory University School of Medicine , Atlanta , GA , USA
| | - Brian W Haas
- c Department of Psychology , University of Georgia , Athens , GA , USA
| | - Alicia K Smith
- a Department of Gynecology and Obstetrics , Emory University School of Medicine , Atlanta , GA , USA.,b Department of Psychiatry and Behavioral Sciences , Emory University School of Medicine , Atlanta , GA , USA
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Schwartz MW, Seeley RJ, Zeltser LM, Drewnowski A, Ravussin E, Redman LM, Leibel RL. Obesity Pathogenesis: An Endocrine Society Scientific Statement. Endocr Rev 2017; 38:267-296. [PMID: 28898979 PMCID: PMC5546881 DOI: 10.1210/er.2017-00111] [Citation(s) in RCA: 373] [Impact Index Per Article: 53.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Accepted: 05/12/2017] [Indexed: 02/07/2023]
Abstract
Obesity is among the most common and costly chronic disorders worldwide. Estimates suggest that in the United States obesity affects one-third of adults, accounts for up to one-third of total mortality, is concentrated among lower income groups, and increasingly affects children as well as adults. A lack of effective options for long-term weight reduction magnifies the enormity of this problem; individuals who successfully complete behavioral and dietary weight-loss programs eventually regain most of the lost weight. We included evidence from basic science, clinical, and epidemiological literature to assess current knowledge regarding mechanisms underlying excess body-fat accumulation, the biological defense of excess fat mass, and the tendency for lost weight to be regained. A major area of emphasis is the science of energy homeostasis, the biological process that maintains weight stability by actively matching energy intake to energy expenditure over time. Growing evidence suggests that obesity is a disorder of the energy homeostasis system, rather than simply arising from the passive accumulation of excess weight. We need to elucidate the mechanisms underlying this "upward setting" or "resetting" of the defended level of body-fat mass, whether inherited or acquired. The ongoing study of how genetic, developmental, and environmental forces affect the energy homeostasis system will help us better understand these mechanisms and are therefore a major focus of this statement. The scientific goal is to elucidate obesity pathogenesis so as to better inform treatment, public policy, advocacy, and awareness of obesity in ways that ultimately diminish its public health and economic consequences.
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Affiliation(s)
| | - Randy J Seeley
- Department of Surgery, University of Michigan, Ann Arbor, Michigan 48109
| | - Lori M Zeltser
- Naomi Berrie Diabetes Center and Department of Pathology and Cell Biology, Columbia University, New York, New York 10032
| | - Adam Drewnowski
- Center for Public Health Nutrition, University of Washington, Seattle, Washington 98195
| | - Eric Ravussin
- John S. McIlhenny Skeletal Muscle Physiology Laboratory, Pennington Biomedical Research Center, Baton Rouge, Louisiana 70808
| | - Leanne M Redman
- John S. McIlhenny Skeletal Muscle Physiology Laboratory, Pennington Biomedical Research Center, Baton Rouge, Louisiana 70808
| | - Rudolph L Leibel
- Naomi Berrie Diabetes Center and Department of Pathology and Cell Biology, Columbia University, New York, New York 10032.,Division of Molecular Genetics, Department of Pediatrics, Columbia University, New York, New York 10032
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Oelsner KT, Guo Y, To SBC, Non AL, Barkin SL. Maternal BMI as a predictor of methylation of obesity-related genes in saliva samples from preschool-age Hispanic children at-risk for obesity. BMC Genomics 2017; 18:57. [PMID: 28068899 PMCID: PMC5223358 DOI: 10.1186/s12864-016-3473-9] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Accepted: 12/26/2016] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND The study of epigenetic processes and mechanisms present a dynamic approach to assess complex individual variation in obesity susceptibility. However, few studies have examined epigenetic patterns in preschool-age children at-risk for obesity despite the relevance of this developmental stage to trajectories of weight gain. We hypothesized that salivary DNA methylation patterns of key obesogenic genes in Hispanic children would 1) correlate with maternal BMI and 2) allow for identification of pathways associated with children at-risk for obesity. RESULTS Genome-wide DNA methylation was conducted on 92 saliva samples collected from Hispanic preschool children using the Infinium Illumina HumanMethylation 450 K BeadChip (Illumina, San Diego, CA, USA), which interrogates >484,000 CpG sites associated with ~24,000 genes. The analysis was limited to 936 genes that have been associated with obesity in a prior GWAS Study. Child DNA methylation at 17 CpG sites was found to be significantly associated with maternal BMI, with increased methylation at 12 CpG sites and decreased methylation at 5 CpG sites. Pathway analysis revealed methylation at these sites related to homocysteine and methionine degradation as well as cysteine biosynthesis and circadian rhythm. Furthermore, eight of the 17 CpG sites reside in genes (FSTL1, SORCS2, NRF1, DLC1, PPARGC1B, CHN2, NXPH1) that have prior known associations with obesity, diabetes, and the insulin pathway. CONCLUSIONS Our study confirms that saliva is a practical human tissue to obtain in community settings and in pediatric populations. These salivary findings indicate potential epigenetic differences in Hispanic preschool children at risk for pediatric obesity. Identifying early biomarkers and understanding pathways that are epigenetically regulated during this critical stage of child development may present an opportunity for prevention or early intervention for addressing childhood obesity. TRIAL REGISTRATION The clinical trial protocol is available at ClinicalTrials.gov ( NCT01316653 ). Registered 3 March 2011.
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Affiliation(s)
- Kathryn Tully Oelsner
- College of Medicine, Medical University of South Carolina, 96 Jonathan Lucas St, Suite 601, MSC 617, Charleston, SC 29425 USA
| | - Yan Guo
- Center for Quantitative Research, School of Medicine, Vanderbilt University, 2220 Pierce Ave, 571 Preston Research Building, Nashville, TN USA
| | - Sophie Bao-Chieu To
- Department of Biological Sciences, Vanderbilt University, 1210 BSB, 465 21st Ave S, Nashville, TN USA
| | - Amy L. Non
- Department of Anthropology, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093 USA
| | - Shari L. Barkin
- Department of Pediatrics, Vanderbilt University School of Medicine, 2200 Children’s Way, Doctor’s Office Tower 8232, Nashville, TN 37232-9225 USA
- Pediatric Obesity Research, Diabetes Research and Training Center, Vanderbilt University School of Medicine, 2200 Children’s Way, Doctor’s Office Tower 8232, Nashville, TN 37232-9225 USA
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Dirks RAM, Stunnenberg HG, Marks H. Genome-wide epigenomic profiling for biomarker discovery. Clin Epigenetics 2016; 8:122. [PMID: 27895806 PMCID: PMC5117701 DOI: 10.1186/s13148-016-0284-4] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2016] [Accepted: 11/02/2016] [Indexed: 12/24/2022] Open
Abstract
A myriad of diseases is caused or characterized by alteration of epigenetic patterns, including changes in DNA methylation, post-translational histone modifications, or chromatin structure. These changes of the epigenome represent a highly interesting layer of information for disease stratification and for personalized medicine. Traditionally, epigenomic profiling required large amounts of cells, which are rarely available with clinical samples. Also, the cellular heterogeneity complicates analysis when profiling clinical samples for unbiased genome-wide biomarker discovery. Recent years saw great progress in miniaturization of genome-wide epigenomic profiling, enabling large-scale epigenetic biomarker screens for disease diagnosis, prognosis, and stratification on patient-derived samples. All main genome-wide profiling technologies have now been scaled down and/or are compatible with single-cell readout, including: (i) Bisulfite sequencing to determine DNA methylation at base-pair resolution, (ii) ChIP-Seq to identify protein binding sites on the genome, (iii) DNaseI-Seq/ATAC-Seq to profile open chromatin, and (iv) 4C-Seq and HiC-Seq to determine the spatial organization of chromosomes. In this review we provide an overview of current genome-wide epigenomic profiling technologies and main technological advances that allowed miniaturization of these assays down to single-cell level. For each of these technologies we evaluate their application for future biomarker discovery. We will focus on (i) compatibility of these technologies with methods used for clinical sample preservation, including methods used by biobanks that store large numbers of patient samples, and (ii) automation of these technologies for robust sample preparation and increased throughput.
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Affiliation(s)
- René A M Dirks
- Department of Molecular Biology, Faculty of Science, Radboud Institute for Molecular Life Sciences, Radboud University, 6500HB Nijmegen, The Netherlands
| | - Hendrik G Stunnenberg
- Department of Molecular Biology, Faculty of Science, Radboud Institute for Molecular Life Sciences, Radboud University, 6500HB Nijmegen, The Netherlands
| | - Hendrik Marks
- Department of Molecular Biology, Faculty of Science, Radboud Institute for Molecular Life Sciences, Radboud University, 6500HB Nijmegen, The Netherlands
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Raciti GA, Longo M, Parrillo L, Ciccarelli M, Mirra P, Ungaro P, Formisano P, Miele C, Béguinot F. Understanding type 2 diabetes: from genetics to epigenetics. Acta Diabetol 2015; 52:821-7. [PMID: 25841587 DOI: 10.1007/s00592-015-0741-0] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Accepted: 03/14/2015] [Indexed: 12/18/2022]
Abstract
The known genetic variability (common DNA polymorphisms) does not account either for the current epidemics of type 2 diabetes or for the family transmission of this disorder. However, clinical, epidemiological and, more recently, experimental evidence indicates that environmental factors have an extraordinary impact on the natural history of type 2 diabetes. Some of these environmental hits are often shared in family groups and proved to be capable to induce epigenetic changes which alter the function of genes affecting major diabetes traits. Thus, epigenetic mechanisms may explain the environmental origin as well as the familial aggregation of type 2 diabetes much easier than common polymorphisms. In the murine model, exposure of parents to environmental hits known to cause epigenetic changes reprograms insulin sensitivity as well as beta-cell function in the progeny, indicating that certain epigenetic changes can be transgenerationally transmitted. Studies from different laboratories revealed that, in humans, lifestyle intervention modulates the epigenome and reverts environmentally induced epigenetic modifications at specific target genes. Finally, specific human epigenotypes have been identified which predict adiposity and type 2 diabetes with much greater power than any polymorphism so far identified. These epigenotypes can be recognized in easily accessible white cells from peripheral blood, indicating that, in the future, epigenetic profiling may enable effective type 2 diabetes prediction. This review discusses recent evidence from the literature supporting the immediate need for further investigation to uncover the power of epigenetics in the prediction, prevention and treatment of type 2 diabetes.
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Affiliation(s)
- Gregory Alexander Raciti
- Dipartimento di Scienze Mediche Traslazionali, "Federico II" University of Naples Medical School, Naples, Italy
- Istituto per l' Endocrinologia e l' Oncologia Sperimentale del C.N.R, URT "Genomica Funzionale", Via Sergio Pansini, 5, 80131, Naples, Italy
| | - Michele Longo
- Dipartimento di Scienze Mediche Traslazionali, "Federico II" University of Naples Medical School, Naples, Italy
- Istituto per l' Endocrinologia e l' Oncologia Sperimentale del C.N.R, URT "Genomica Funzionale", Via Sergio Pansini, 5, 80131, Naples, Italy
| | - Luca Parrillo
- Dipartimento di Scienze Mediche Traslazionali, "Federico II" University of Naples Medical School, Naples, Italy
- Istituto per l' Endocrinologia e l' Oncologia Sperimentale del C.N.R, URT "Genomica Funzionale", Via Sergio Pansini, 5, 80131, Naples, Italy
| | - Marco Ciccarelli
- Dipartimento di Scienze Mediche Traslazionali, "Federico II" University of Naples Medical School, Naples, Italy
- Istituto per l' Endocrinologia e l' Oncologia Sperimentale del C.N.R, URT "Genomica Funzionale", Via Sergio Pansini, 5, 80131, Naples, Italy
| | - Paola Mirra
- Dipartimento di Scienze Mediche Traslazionali, "Federico II" University of Naples Medical School, Naples, Italy
- Istituto per l' Endocrinologia e l' Oncologia Sperimentale del C.N.R, URT "Genomica Funzionale", Via Sergio Pansini, 5, 80131, Naples, Italy
| | - Paola Ungaro
- Dipartimento di Scienze Mediche Traslazionali, "Federico II" University of Naples Medical School, Naples, Italy
- Istituto per l' Endocrinologia e l' Oncologia Sperimentale del C.N.R, URT "Genomica Funzionale", Via Sergio Pansini, 5, 80131, Naples, Italy
| | - Pietro Formisano
- Dipartimento di Scienze Mediche Traslazionali, "Federico II" University of Naples Medical School, Naples, Italy
- Istituto per l' Endocrinologia e l' Oncologia Sperimentale del C.N.R, URT "Genomica Funzionale", Via Sergio Pansini, 5, 80131, Naples, Italy
| | - Claudia Miele
- Dipartimento di Scienze Mediche Traslazionali, "Federico II" University of Naples Medical School, Naples, Italy
- Istituto per l' Endocrinologia e l' Oncologia Sperimentale del C.N.R, URT "Genomica Funzionale", Via Sergio Pansini, 5, 80131, Naples, Italy
| | - Francesco Béguinot
- Dipartimento di Scienze Mediche Traslazionali, "Federico II" University of Naples Medical School, Naples, Italy.
- Istituto per l' Endocrinologia e l' Oncologia Sperimentale del C.N.R, URT "Genomica Funzionale", Via Sergio Pansini, 5, 80131, Naples, Italy.
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Tan Q, Christiansen L, von Bornemann Hjelmborg J, Christensen K. Twin methodology in epigenetic studies. ACTA ACUST UNITED AC 2015; 218:134-9. [PMID: 25568460 DOI: 10.1242/jeb.107151] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Since the final decades of the last century, twin studies have made a remarkable contribution to the genetics of human complex traits and diseases. With the recent rapid development in modern biotechnology of high-throughput genetic and genomic analyses, twin modelling is expanding from analysis of diseases to molecular phenotypes in functional genomics especially in epigenetics, a thriving field of research that concerns the environmental regulation of gene expression through DNA methylation, histone modification, microRNA and long non-coding RNA expression, etc. The application of the twin method to molecular phenotypes offers new opportunities to study the genetic (nature) and environmental (nurture) contributions to epigenetic regulation of gene activity during developmental, ageing and disease processes. Besides the classical twin model, the case co-twin design using identical twins discordant for a trait or disease is becoming a popular and powerful design for epigenome-wide association study in linking environmental exposure to differential epigenetic regulation and to disease status while controlling for individual genetic make-up. It can be expected that novel uses of twin methods in epigenetic studies are going to help with efficiently unravelling the genetic and environmental basis of epigenomics in human complex diseases.
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Affiliation(s)
- Qihua Tan
- Epidemiology, Biostatistics and Bio-demography, Institute of Public Health, University of Southern Denmark, DK-5000, Odense C, Denmark Human Genetics, Institute of Clinical Research, University of Southern Denmark, DK-5000, Odense C, Denmark
| | - Lene Christiansen
- Epidemiology, Biostatistics and Bio-demography, Institute of Public Health, University of Southern Denmark, DK-5000, Odense C, Denmark Human Genetics, Institute of Clinical Research, University of Southern Denmark, DK-5000, Odense C, Denmark
| | - Jacob von Bornemann Hjelmborg
- Epidemiology, Biostatistics and Bio-demography, Institute of Public Health, University of Southern Denmark, DK-5000, Odense C, Denmark
| | - Kaare Christensen
- Epidemiology, Biostatistics and Bio-demography, Institute of Public Health, University of Southern Denmark, DK-5000, Odense C, Denmark Human Genetics, Institute of Clinical Research, University of Southern Denmark, DK-5000, Odense C, Denmark
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10
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van Dongen J, Willemsen G, Heijmans BT, Neuteboom J, Kluft C, Jansen R, Penninx BWJ, Slagboom PE, de Geus EJC, Boomsma DI. Longitudinal weight differences, gene expression and blood biomarkers in BMI-discordant identical twins. Int J Obes (Lond) 2015; 39:899-909. [PMID: 25765203 PMCID: PMC4471109 DOI: 10.1038/ijo.2015.24] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2014] [Revised: 11/28/2014] [Accepted: 12/18/2014] [Indexed: 12/31/2022]
Abstract
Background BMI discordant monozygotic (MZ) twins allows an examination of the causes and consequences of adiposity in a genetically controlled design. Few studies have examined longitudinal BMI discordance in MZ pairs. Objectives To study the development over time of BMI discordance in adolescent and adult MZ twin pairs, and to examine lifestyle, metabolic, inflammatory, and gene expression differences associated with concurrent and long-term BMI discordance in MZ pairs. Subjects/Methods BMI data from 2775 MZ twin pairs, collected in eight longitudinal surveys and a biobank project between 1991 and 2011, were analyzed to characterize longitudinal discordance. Lifestyle characteristics were compared within discordant pairs (ΔBMI ≥ 3 kg/m2) and biomarkers (lipids, glucose, insulin, CRP, fibrinogen, IL-6, TNF-α and sIL-6R and liver enzymes AST, ALT and GGT) and gene expression were compared in peripheral blood from discordant pairs who participated in the NTR biobank project. Results The prevalence of discordance ranged from 3.2% in 1991 (mean age=17, SD=2.4) to 17.4% (N=202 pairs) in 2009 (mean age=35, SD=15), and was 16.5% (N=174) among pairs participating in the biobank project (mean age=35, SD=12). Of 699 MZ with BMI data from 3-5 time points, 17 pairs (2.4%) were long-term discordant (at all available time points; mean follow-up range=6.4 years). Concurrently discordant pairs showed significant differences in self-ratings of which twin eats most (p=2.3×10−13), but not in leisure time exercise activity (p=0.28) and smoking (p>0.05). Ten out of 14 biomarkers showed significantly more unfavorable levels in the heavier of twin of the discordant pairs (p-values < 0.001); most of these biomarker differences were largest in longitudinally discordant pairs. No significant gene expression differences were identified, although high ranking genes were enriched for Gene Ontology (GO) terms highlighting metabolic gene regulation and inflammation pathways. Conclusions BMI discordance is uncommon in adolescent identical pairs but increases with higher pair-mean of BMI at older ages, although long-term BMI discordance is rare. In discordant pairs, the heavier twin had a more unfavorable blood biomarker profile than the genetically matched leaner twin, in support of causal effects of obesity.
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Affiliation(s)
- J van Dongen
- 1] Department of Biological Psychology, VU University Amsterdam, Amsterdam, The Netherlands [2] EMGO Institute for Health and Care Research, VU University Medical Center, Amsterdam, The Netherlands
| | - G Willemsen
- 1] Department of Biological Psychology, VU University Amsterdam, Amsterdam, The Netherlands [2] EMGO Institute for Health and Care Research, VU University Medical Center, Amsterdam, The Netherlands
| | - B T Heijmans
- Department of Molecular Epidemiology, Leiden University Medical Center, Leiden, The Netherlands
| | - J Neuteboom
- Good Biomarker Sciences, Leiden, The Netherlands
| | - C Kluft
- Good Biomarker Sciences, Leiden, The Netherlands
| | - R Jansen
- Department of Psychiatry, VU University Medical Center, Amsterdam, The Netherlands
| | - B W J Penninx
- 1] EMGO Institute for Health and Care Research, VU University Medical Center, Amsterdam, The Netherlands [2] Department of Psychiatry, VU University Medical Center, Amsterdam, The Netherlands
| | - P E Slagboom
- Department of Molecular Epidemiology, Leiden University Medical Center, Leiden, The Netherlands
| | - E J C de Geus
- 1] Department of Biological Psychology, VU University Amsterdam, Amsterdam, The Netherlands [2] EMGO Institute for Health and Care Research, VU University Medical Center, Amsterdam, The Netherlands
| | - D I Boomsma
- 1] Department of Biological Psychology, VU University Amsterdam, Amsterdam, The Netherlands [2] EMGO Institute for Health and Care Research, VU University Medical Center, Amsterdam, The Netherlands
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11
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Twin studies advance the understanding of gene–environment interplay in human nutrigenomics. Nutr Res Rev 2014; 27:242-51. [DOI: 10.1017/s095442241400016x] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Investigations into the genetic architecture of diet–disease relationships are particularly relevant today with the global epidemic of obesity and chronic disease. Twin studies have demonstrated that genetic makeup plays a significant role in a multitude of dietary phenotypes such as energy and macronutrient intakes, dietary patterns, and specific food group intakes. Besides estimating heritability of dietary assessment, twins provide a naturally unique, case–control experiment. Due to their shared upbringing, matched genes and sex (in the case of monozygotic (MZ) twin pairs), and age, twins provide many advantages over classic epidemiological approaches. Future genetic epidemiological studies could benefit from the twin approach particularly where defining what is ‘normal’ is problematic due to the high inter-individual variability underlying metabolism. Here, we discuss the use of twins to generate heritability estimates of food intake phenotypes. We then highlight the value of discordant MZ pairs to further nutrition research through discovery and validation of biomarkers of intake and health status in collaboration with cutting-edge omics technologies.
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DNA methylation biomarkers: cancer and beyond. Genes (Basel) 2014; 5:821-64. [PMID: 25229548 PMCID: PMC4198933 DOI: 10.3390/genes5030821] [Citation(s) in RCA: 173] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2014] [Revised: 08/17/2014] [Accepted: 09/01/2014] [Indexed: 12/23/2022] Open
Abstract
Biomarkers are naturally-occurring characteristics by which a particular pathological process or disease can be identified or monitored. They can reflect past environmental exposures, predict disease onset or course, or determine a patient's response to therapy. Epigenetic changes are such characteristics, with most epigenetic biomarkers discovered to date based on the epigenetic mark of DNA methylation. Many tissue types are suitable for the discovery of DNA methylation biomarkers including cell-based samples such as blood and tumor material and cell-free DNA samples such as plasma. DNA methylation biomarkers with diagnostic, prognostic and predictive power are already in clinical trials or in a clinical setting for cancer. Outside cancer, strong evidence that complex disease originates in early life is opening up exciting new avenues for the detection of DNA methylation biomarkers for adverse early life environment and for estimation of future disease risk. However, there are a number of limitations to overcome before such biomarkers reach the clinic. Nevertheless, DNA methylation biomarkers have great potential to contribute to personalized medicine throughout life. We review the current state of play for DNA methylation biomarkers, discuss the barriers that must be crossed on the way to implementation in a clinical setting, and predict their future use for human disease.
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Waterland RA. Epigenetic mechanisms affecting regulation of energy balance: many questions, few answers. Annu Rev Nutr 2014; 34:337-55. [PMID: 24850387 DOI: 10.1146/annurev-nutr-071813-105315] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Extensive human and animal model data show that nutrition and other environmental influences during critical periods of embryonic, fetal, and early postnatal life can affect the development of body weight regulatory pathways, with permanent consequences for risk of obesity. Epigenetic processes are widely viewed as a leading mechanism to explain the lifelong persistence of such "developmental programming" of energy balance. Despite meaningful progress in recent years, however, significant research obstacles impede our ability to test this hypothesis. Accordingly, this review attempts to summarize progress toward answering the following outstanding questions: Is epigenetic dysregulation a major cause of human obesity? In what cells/tissues is epigenetic regulation most important for energy balance? Does developmental programming of human body weight regulation occur via epigenetic mechanisms? Do epigenetic mechanisms have a greater impact on food intake or energy expenditure? Does epigenetic inheritance contribute to transgenerational patterns of obesity? In each case, significant obstacles and suggested approaches to surmounting them are elaborated.
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Affiliation(s)
- Robert A Waterland
- Departments of Pediatrics and Molecular & Human Genetics, Baylor College of Medicine, USDA/ARS Children's Nutrition Research Center, Houston, Texas 77030;
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Symonds ME, Budge H, Frazier-Wood AC. Epigenetics and obesity: a relationship waiting to be explained. Hum Hered 2013; 75:90-7. [PMID: 24081224 DOI: 10.1159/000352009] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Obesity can have multifactorial causes that may change with development and are not simply attributable to one's genetic constitution. To date, expensive and laborious genome-wide association studies have only ascribed a small contribution of genetic variants to obesity. The emergence of the field of epigenetics now offers a new paradigm with which to study excess fat mass. Currently, however, there are no compelling epigenetic studies to explain the role of epigenetics in obesity, especially from a developmental perspective. It is clear that until there are advances in the understanding of the main mechanisms by which different fat types, i.e. brown, beige, and white, are established and how these differ between depots and species, population-based studies designed to determine specific aspects of epigenetics will be potentially limited. Obesity is a slowly evolving condition that is not simply explained by changes in the intake of one macronutrient. The latest advances in epigenetics, coupled with the establishment of relevant longitudinal models of obesity, which incorporate functionally relevant end points, may now permit the precise contribution of epigenetic modifications to excess fat mass to be effectively studied.
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Affiliation(s)
- Michael E Symonds
- Early Life Nutrition Research Unit, Academic Division of Child Health, School of Medicine, University Hospital, The University of Nottingham, Nottingham, UK
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Souren NYP, Lutsik P, Gasparoni G, Tierling S, Gries J, Riemenschneider M, Fryns JP, Derom C, Zeegers MP, Walter J. Adult monozygotic twins discordant for intra-uterine growth have indistinguishable genome-wide DNA methylation profiles. Genome Biol 2013; 14:R44. [PMID: 23706164 PMCID: PMC4054831 DOI: 10.1186/gb-2013-14-5-r44] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2013] [Accepted: 05/26/2013] [Indexed: 01/21/2023] Open
Abstract
Background Low birth weight is associated with an increased adult metabolic disease risk. It is widely discussed that poor intra-uterine conditions could induce long-lasting epigenetic modifications, leading to systemic changes in regulation of metabolic genes. To address this, we acquire genome-wide DNA methylation profiles from saliva DNA in a unique cohort of 17 monozygotic monochorionic female twins very discordant for birth weight. We examine if adverse prenatal growth conditions experienced by the smaller co-twins lead to long-lasting DNA methylation changes. Results Overall, co-twins show very similar genome-wide DNA methylation profiles. Since observed differences are almost exclusively caused by variable cellular composition, an original marker-based adjustment strategy was developed to eliminate such variation at affected CpGs. Among adjusted and unchanged CpGs 3,153 are differentially methylated between the heavy and light co-twins at nominal significance, of which 45 show sensible absolute mean β-value differences. Deep bisulfite sequencing of eight such loci reveals that differences remain in the range of technical variation, arguing against a reproducible biological effect. Analysis of methylation in repetitive elements using methylation-dependent primer extension assays also indicates no significant intra-pair differences. Conclusions Severe intra-uterine growth differences observed within these monozygotic twins are not associated with long-lasting DNA methylation differences in cells composing saliva, detectable with up-to-date technologies. Additionally, our results indicate that uneven cell type composition can lead to spurious results and should be addressed in epigenomic studies.
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Abstract
The East Flanders Prospective Twin Survey (EFPTS) is a prospective, population-based registry of multiple births in the province of East-Flanders, Belgium. EFPTS has several unique features: it is population-based and prospective, with the possibility of long-term follow-up; the twins (and higher order multiple births) are recruited at birth; basic perinatal data recorded; chorion type and zygosity established; and since 1969 placental biopsies have been taken and frozen at −20 °C for later determination of genetic markers. The EFPTS is the only large register that includes placental data and allows differentiation of three subtypes of monozygotic (MZ) twins based on the time of the initial zygotic division: the dichorionic–diamnionic pairs (early, with splitting before the fourth day after fertilization), the monochorionic–diamnionic pairs (intermediate, splitting between the fourth and the seventh day post-fertilization), and the monochorionic–monoamnionic pairs (late, splitting after the eighth day post-fertilization). Studies can be initiated taking into account primary biases, those originating ‘in utero’. Such studies could throw new light on the controversy over the validity of the classic twin method, the consequences of early embryological events, and the gene–environment interactions as far as periconceptional and intrauterine environment are concerned.
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17
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Czyz W, Morahan JM, Ebers GC, Ramagopalan SV. Genetic, environmental and stochastic factors in monozygotic twin discordance with a focus on epigenetic differences. BMC Med 2012; 10:93. [PMID: 22898292 PMCID: PMC3566971 DOI: 10.1186/1741-7015-10-93] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2012] [Accepted: 08/17/2012] [Indexed: 03/16/2023] Open
Abstract
Genetic-epidemiological studies on monozygotic (MZ) twins have been used for decades to tease out the relative contributions of genes and the environment to a trait. Phenotypic discordance in MZ twins has traditionally been ascribed to non-shared environmental factors acting after birth, however recent data indicate that this explanation is far too simple. In this paper, we review other reasons for discordance, including differences in the in utero environment, genetic mosaicism, and stochastic factors, focusing particularly on epigenetic discordance. Epigenetic differences are gaining increasing recognition. Although it is clear that in specific cases epigenetic alterations provide a causal factor in disease etiology, the overall significance of epigenetics in twin discordance remains unclear. It is also challenging to determine the causality and relative contributions of environmental, genetic, and stochastic factors to epigenetic variability. Epigenomic profiling studies have recently shed more light on the dynamics of temporal methylation change and methylome heritability, yet have not given a definite answer regarding their relevance to disease, because of limitations in establishing causality. Here, we explore the subject of epigenetics as another component in human phenotypic variability and its links to disease focusing particularly on evidence from MZ twin studies.
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Affiliation(s)
- Witold Czyz
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK
- Nuffield Department of Clinical Neurosciences (Clinical Neurology), University of Oxford, Oxford, UK
| | - Julia M Morahan
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK
- Nuffield Department of Clinical Neurosciences (Clinical Neurology), University of Oxford, Oxford, UK
| | - George C Ebers
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK
- Nuffield Department of Clinical Neurosciences (Clinical Neurology), University of Oxford, Oxford, UK
| | - Sreeram V Ramagopalan
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK
- Nuffield Department of Clinical Neurosciences (Clinical Neurology), University of Oxford, Oxford, UK
- Blizard Institute, Queen Mary University of London, Barts and The London School of Medicine and Dentistry, London, UK
- London School of Hygiene and Tropical Medicine, London, UK
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