201
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Nwanaji-Enwerem JC, Weisskopf MG, Baccarelli AA. Multi-tissue DNA methylation age: Molecular relationships and perspectives for advancing biomarker utility. Ageing Res Rev 2018; 45:15-23. [PMID: 29698722 PMCID: PMC6047923 DOI: 10.1016/j.arr.2018.04.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Revised: 03/29/2018] [Accepted: 04/18/2018] [Indexed: 12/31/2022]
Abstract
The multi-tissue DNA methylation estimator of chronological age (DNAm-age) has been associated with a wide range of exposures and health outcomes. Still, it is unclear how DNAm-age can have such broad relationships and how it can be best utilized as a biomarker. Understanding DNAm-age's molecular relationships is a promising approach to address this critical knowledge gap. In this review, we discuss the existing literature regarding DNAm-age's molecular relationships in six major categories: animal model systems, cancer processes, cellular aging processes, immune system processes, metabolic processes, and nucleic acid processes. We also present perspectives regarding the future of DNAm-age research, including the need to translate a greater number of ongoing research efforts to experimental and animal model systems.
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Affiliation(s)
- Jamaji C Nwanaji-Enwerem
- Department of Environmental Health, Harvard T.H. Chan School of Public Health and MD-PhD Program, Harvard Medical School, Boston, MA, USA.
| | - Marc G Weisskopf
- Department of Environmental Health and Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Andrea A Baccarelli
- Department of Environmental Health Sciences, Columbia Mailman School of Public Health, New York, NY, USA
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202
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Wright PGR, Mathews F, Schofield H, Morris C, Burrage J, Smith A, Dempster EL, Hamilton PB. Application of a novel molecular method to age free-living wild Bechstein's bats. Mol Ecol Resour 2018; 18:1374-1380. [PMID: 29981199 DOI: 10.1111/1755-0998.12925] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Revised: 04/21/2018] [Accepted: 05/02/2018] [Indexed: 11/26/2022]
Abstract
The age profile of populations fundamentally affects their conservation status. Yet, age is frequently difficult to assess in wild animals. Here, we assessed the use of DNA methylation of homologous genes to establish the age structure of a rare and elusive wild mammal: the Bechstein's bat (Myotis bechsteinii). We collected 62 wing punches from individuals whose ages were known as a result of a long-term banding study. DNA methylation was measured at seven CpG sites from three genes, which have previously shown age-associated changes in humans and laboratory mice. All CpG sites from the tested genes showed a significant relationship between DNA methylation and age, both individually and in combination (multiple linear regression R2 = 0.58, p < 0.001). Despite slight approximation around estimates, the approach is sufficiently precise to place animals into practically useful age cohorts. This method is of considerable practical benefit as it can reliably age individual bats. It is also much faster than traditional capture-mark-recapture techniques, with the potential to collect information on the age structure of an entire colony from a single sampling session to better inform conservation actions for Bechstein's bats. By identifying three genes where DNA methylation correlates with age across distantly related species, this study also suggests that the technique can potentially be applied across a wide range of mammals.
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Affiliation(s)
- Patrick G R Wright
- Bioscience, College of Life and Environmental Sciences, University of Exeter, Exeter, UK
| | - Fiona Mathews
- College of Life Sciences, University of Sussex, Falmer, UK
| | | | - Colin Morris
- The Vincent Wildlife Trust, Ledbury, Herefordshire, UK
| | - Joe Burrage
- Exeter Medical School, University of Exeter, Exeter, UK
| | - Adam Smith
- Exeter Medical School, University of Exeter, Exeter, UK
| | | | - Patrick B Hamilton
- Bioscience, College of Life and Environmental Sciences, University of Exeter, Exeter, UK
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203
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Sziráki A, Tyshkovskiy A, Gladyshev VN. Global remodeling of the mouse DNA methylome during aging and in response to calorie restriction. Aging Cell 2018; 17:e12738. [PMID: 29575528 PMCID: PMC5946071 DOI: 10.1111/acel.12738] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/23/2018] [Indexed: 01/08/2023] Open
Abstract
Aging is characterized by numerous molecular changes, such as accumulation of molecular damage and altered gene expression, many of which are linked to DNA methylation. Here, we characterize the blood DNA methylome across 16 age groups of mice and report numerous global, region‐ and site‐specific features, as well as the associated dynamics of methylation changes. Transition of the methylome throughout lifespan was not uniform, with many sites showing accelerated changes in late life. The associated genes and promoters were enriched for aging‐related pathways, pointing to a fundamental link between DNA methylation and control of the aging process. Calorie restriction both shifted the overall methylation pattern and was accompanied by its gradual age‐related remodeling, the latter contributing to the lifespan‐extending effect. With age, both highly and poorly methylated sites trended toward intermediate levels, and aging was accompanied by an accelerated increase in entropy, consistent with damage accumulation. However, the entropy effects differed for the sites that increased, decreased and did not change methylation with age. Many sites trailed behind, whereas some followed or even exceeded the entropy trajectory and altered the developmental DNA methylation pattern. The patterns we observed in certain genomic regions were conserved between humans and mice, suggesting common principles of functional DNA methylome remodeling and its critical role in aging. The highly resolved DNA methylome remodeling provides an excellent model for understanding systemic changes that characterize the aging process.
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Affiliation(s)
- András Sziráki
- Division of Genetics; Department of Medicine; Brigham and Women's Hospital and Harvard Medical School; Boston MA USA
| | - Alexander Tyshkovskiy
- Division of Genetics; Department of Medicine; Brigham and Women's Hospital and Harvard Medical School; Boston MA USA
- Center for Data-Intensive Biomedicine and Biotechnology; Skolkovo Institute of Science and Technology; Moscow Russia
| | - Vadim N. Gladyshev
- Division of Genetics; Department of Medicine; Brigham and Women's Hospital and Harvard Medical School; Boston MA USA
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204
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Cui D, Xu X. DNA Methyltransferases, DNA Methylation, and Age-Associated Cognitive Function. Int J Mol Sci 2018; 19:E1315. [PMID: 29710796 PMCID: PMC5983821 DOI: 10.3390/ijms19051315] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Revised: 04/20/2018] [Accepted: 04/20/2018] [Indexed: 12/16/2022] Open
Abstract
Ageing, a leading cause of the decline/deficits in human learning, memory, and cognitive abilities, is a major risk factor for age-associated neurodegenerative disorders such as Alzheimer’s disease. Emerging evidence suggests that epigenetics, an inheritable but reversible biochemical process, plays a crucial role in the pathogenesis of age-related neurological disorders. DNA methylation, the best-known epigenetic mark, has attracted most attention in this regard. DNA methyltransferases (DNMTs) are key enzymes in mediating the DNA methylation process, by which a methyl group is transferred, faithfully or anew, to genomic DNA sequences. Biologically, DNMTs are important for gene imprinting. Accumulating evidence suggests that DNMTs not only play critical roles, including gene imprinting and transcription regulation, in early development stages of the central nervous system (CNS), but also are indispensable in adult learning, memory, and cognition. Therefore, the impact of DNMTs and DNA methylation on age-associated cognitive functions and neurodegenerative diseases has emerged as a pivotal topic in the field. In this review, the effects of each DNMT on CNS development and healthy and pathological ageing are discussed.
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Affiliation(s)
- Di Cui
- Max Planck Institute for Biology of Ageing, 50931 Cologne, Germany.
| | - Xiangru Xu
- Max Planck Institute for Biology of Ageing, 50931 Cologne, Germany.
- Department of Anesthesiology, Yale University School of Medicine, New Haven, CT 06520, USA.
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205
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Lowe R, Barton C, Jenkins CA, Ernst C, Forman O, Fernandez-Twinn DS, Bock C, Rossiter SJ, Faulkes CG, Ozanne SE, Walter L, Odom DT, Mellersh C, Rakyan VK. Ageing-associated DNA methylation dynamics are a molecular readout of lifespan variation among mammalian species. Genome Biol 2018; 19:22. [PMID: 29452591 PMCID: PMC5815211 DOI: 10.1186/s13059-018-1397-1] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Accepted: 01/19/2018] [Indexed: 02/02/2023] Open
Abstract
BACKGROUND Mammalian species exhibit a wide range of lifespans. To date, a robust and dynamic molecular readout of these lifespan differences has not yet been identified. Recent studies have established the existence of ageing-associated differentially methylated positions (aDMPs) in human and mouse. These are CpG sites at which DNA methylation dynamics show significant correlations with age. We hypothesise that aDMPs are pan-mammalian and are a dynamic molecular readout of lifespan variation among different mammalian species. RESULTS A large-scale integrated analysis of aDMPs in six different mammals reveals a strong negative relationship between rate of change of methylation levels at aDMPs and lifespan. This relationship also holds when comparing two different dog breeds with known differences in lifespans. In an ageing cohort of aneuploid mice carrying a complete copy of human chromosome 21, aDMPs accumulate far more rapidly than is seen in human tissues, revealing that DNA methylation at aDMP sites is largely shaped by the nuclear trans-environment and represents a robust molecular readout of the ageing cellular milieu. CONCLUSIONS Overall, we define the first dynamic molecular readout of lifespan differences among mammalian species and propose that aDMPs will be an invaluable molecular tool for future evolutionary and mechanistic studies aimed at understanding the biological factors that determine lifespan in mammals.
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Affiliation(s)
- Robert Lowe
- The Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, E1 2AT, UK.
| | - Carl Barton
- The Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, E1 2AT, UK
| | | | - Christina Ernst
- Cancer Research UK Cambridge Institute, University of Cambridge, Cambridge, CB2 0RE, UK
| | - Oliver Forman
- Kennel Club Genetics Centre, Animal Health Trust, Newmarket, Suffolk, CB8 7UU, UK
| | - Denise S Fernandez-Twinn
- University of Cambridge Metabolic Research Laboratories and MRC Metabolic Diseases Unit, Wellcome Trust-MRC Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge, CB2 0QQ, UK
| | - Christoph Bock
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
- Department of Laboratory Medicine, Medical University of Vienna, Vienna, Austria
- Max Planck Institute for Informatics, Saarland Informatics Campus, Saarbrücken, Germany
- Ludwig Boltzmann Institute for Rare and Undiagnosed Diseases, Vienna, Austria
| | - Stephen J Rossiter
- School of Biological & Chemical Sciences, Queen Mary University of London, Mile End Road, London, E1 4NS, UK
| | - Chris G Faulkes
- School of Biological & Chemical Sciences, Queen Mary University of London, Mile End Road, London, E1 4NS, UK
| | - Susan E Ozanne
- University of Cambridge Metabolic Research Laboratories and MRC Metabolic Diseases Unit, Wellcome Trust-MRC Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge, CB2 0QQ, UK
| | - Lutz Walter
- Primate Genetics Laboratory, Leibniz Institute for Primate Research, German Primate Center, Göttingen, Germany
| | - Duncan T Odom
- Cancer Research UK Cambridge Institute, University of Cambridge, Cambridge, CB2 0RE, UK
| | - Cathryn Mellersh
- Kennel Club Genetics Centre, Animal Health Trust, Newmarket, Suffolk, CB8 7UU, UK
| | - Vardhman K Rakyan
- The Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, E1 2AT, UK.
- Centre for Genomic Health, Queen Mary University of London, EC1M 6BQ, London, UK.
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206
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Masser DR, Hadad N, Porter H, Stout MB, Unnikrishnan A, Stanford DR, Freeman WM. Analysis of DNA modifications in aging research. GeroScience 2018; 40:11-29. [PMID: 29327208 PMCID: PMC5832665 DOI: 10.1007/s11357-018-0005-3] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Accepted: 01/05/2018] [Indexed: 12/22/2022] Open
Abstract
As geroscience research extends into the role of epigenetics in aging and age-related disease, researchers are being confronted with unfamiliar molecular techniques and data analysis methods that can be difficult to integrate into their work. In this review, we focus on the analysis of DNA modifications, namely cytosine methylation and hydroxymethylation, through next-generation sequencing methods. While older techniques for modification analysis performed relative quantitation across regions of the genome or examined average genome levels, these analyses lack the desired specificity, rigor, and genomic coverage to firmly establish the nature of genomic methylation patterns and their response to aging. With recent methodological advances, such as whole genome bisulfite sequencing (WGBS), bisulfite oligonucleotide capture sequencing (BOCS), and bisulfite amplicon sequencing (BSAS), cytosine modifications can now be readily analyzed with base-specific, absolute quantitation at both cytosine-guanine dinucleotide (CG) and non-CG sites throughout the genome or within specific regions of interest by next-generation sequencing. Additional advances, such as oxidative bisulfite conversion to differentiate methylation from hydroxymethylation and analysis of limited input/single-cells, have great promise for continuing to expand epigenomic capabilities. This review provides a background on DNA modifications, the current state-of-the-art for sequencing methods, bioinformatics tools for converting these large data sets into biological insights, and perspectives on future directions for the field.
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Affiliation(s)
- Dustin R Masser
- Reynolds Oklahoma Center on Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- Oklahoma Nathan Shock Center for Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Niran Hadad
- Reynolds Oklahoma Center on Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- Oklahoma Nathan Shock Center for Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- Oklahoma Center for Neuroscience, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Hunter Porter
- Reynolds Oklahoma Center on Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- Oklahoma Nathan Shock Center for Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- Oklahoma Center for Neuroscience, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Michael B Stout
- Reynolds Oklahoma Center on Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- Department of Nutritional Sciences, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Archana Unnikrishnan
- Reynolds Oklahoma Center on Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - David R Stanford
- Reynolds Oklahoma Center on Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- Oklahoma Center for Neuroscience, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Willard M Freeman
- Reynolds Oklahoma Center on Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.
- Oklahoma Nathan Shock Center for Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.
- Oklahoma Center for Neuroscience, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.
- Department of Nutritional Sciences, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.
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207
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Unnikrishnan A, Hadad N, Masser DR, Jackson J, Freeman WM, Richardson A. Revisiting the genomic hypomethylation hypothesis of aging. Ann N Y Acad Sci 2018; 1418:69-79. [PMID: 29363785 DOI: 10.1111/nyas.13533] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Revised: 09/19/2017] [Accepted: 09/26/2017] [Indexed: 12/26/2022]
Abstract
The genomic hypomethylation hypothesis of aging proposes that an overall decrease in global DNA methylation occurs with age, and it has been argued that the decrease in global DNA methylation could be an important factor in aging, resulting in the relaxation of gene expression regulation and abnormal gene expression. Since it was initially observed that DNA methylation decreased with age in 1974, 16 articles have been published describing the effect of age on global DNA methylation in various tissues from rodents and humans. We critically reviewed the publications on the effect of age on DNA methylation and the expression of the enzymes involved in DNA methylation to evaluate the validity of the hypomethylation hypothesis of aging. On the basis of the current scientific literature, we conclude that a decrease in the global methylation of the genome occurs in most if not all tissues/cells as an animal ages. However, age-related changes in DNA methylation in specific regions or at specific sites in the genome occur even though the global DNA methylation does not change.
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Affiliation(s)
- Archana Unnikrishnan
- Reynolds Oklahoma Center on Aging, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma.,Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
| | - Niran Hadad
- Reynolds Oklahoma Center on Aging, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma.,Department of Oklahoma Center for Neuroscience, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
| | - Dustin R Masser
- Reynolds Oklahoma Center on Aging, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma.,Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
| | - Jordan Jackson
- Reynolds Oklahoma Center on Aging, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma.,Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
| | - Willard M Freeman
- Reynolds Oklahoma Center on Aging, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma.,Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
| | - Arlan Richardson
- Reynolds Oklahoma Center on Aging, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma.,Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma.,Oklahoma City VA Medical Center, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
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208
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Declerck K, Vanden Berghe W. Back to the future: Epigenetic clock plasticity towards healthy aging. Mech Ageing Dev 2018; 174:18-29. [PMID: 29337038 DOI: 10.1016/j.mad.2018.01.002] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2017] [Revised: 01/08/2018] [Accepted: 01/10/2018] [Indexed: 12/22/2022]
Abstract
Aging is the most important risk factor for major human lifestyle diseases, including cancer, neurological and cardiometabolic disorders. Due to the complex interplay between genetics, lifestyle and environmental factors, some individuals seem to age faster than others, whereas centenarians seem to have a slower aging process. Therefore, a biochemical biomarker reflecting the relative biological age would be helpful to predict an individual's health status and aging disease risk. Although it is already known for years that cumulative epigenetic changes occur upon aging, DNA methylation patterns were only recently used to construct an epigenetic clock predictor for biological age, which is a measure of how well your body functions compared to your chronological age. Moreover, the epigenetic DNA methylation clock signature is increasingly applied as a biomarker to estimate aging disease susceptibility and mortality risk. Finally, the epigenetic clock signature could be used as a lifestyle management tool to monitor healthy aging, to evaluate preventive interventions against chronic aging disorders and to extend healthy lifespan. Dissecting the mechanism of the epigenetic aging clock will yield valuable insights into the aging process and how it can be manipulated to improve health span.
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Affiliation(s)
- Ken Declerck
- Laboratory of Protein Chemistry, Proteomics and Epigenetic Signaling (PPES), Department of Biomedical Sciences, University of Antwerp (UA), Belgium
| | - Wim Vanden Berghe
- Laboratory of Protein Chemistry, Proteomics and Epigenetic Signaling (PPES), Department of Biomedical Sciences, University of Antwerp (UA), Belgium.
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209
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Abstract
Cancer is largely an aging disease. Accelerated biological aging may be the strongest predictor of cancer and other chronic disease risks. In the absence of reliable and quantifiable biomarkers of aging to date, it has long been observed that tumorigenesis shares distinct epigenetic alterations with the aging process. Recently, epigenetic age estimates have been developed based on the availability of genome-wide DNA methylation profiles, by applying in the prediction formula the methylation level at a subset of highly predictive methylation sites, called epigenetic clock. These DNA methylation age estimates have produced remarkably strong correlations with chronological age, with a small deviation and high reproducibility across different age groups and study populations. Moreover, an increasing number of epidemiologic studies have demonstrated an independent association of DNA methylation age or the extent of acceleration with mortality and various aging-related conditions, even after accounting for differences in chronological age and other risk factors. Although epigenetic profiles are known to be tissue-specific, both target tissue- and multiple tissue-derived estimates appear to perform well to capture what is thought to be the cumulative epigenetic drift that represents a multifactorial degenerative process across tissues and organisms. Further refinement of the epigenetic age estimates is anticipated over time to accommodate a better technological coverage of the methylome and a better understanding of the biology underlying predictive regions. Epidemiologic principles will remain critical for the evaluation of research findings involving, for example, different study populations, design, follow-up time, and quality of covariate data. Overall, the epigenetic age estimates are an exciting development with useful implications for biomedical research of healthy aging and disease prevention and control.
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210
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The Genome-Wide DNA Methylation Profile of Peripheral Blood Is Not Systematically Changed by Short-Time Storage at Room Temperature. EPIGENOMES 2017. [DOI: 10.3390/epigenomes1030023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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211
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Masser DR, Hadad N, Porter HL, Mangold CA, Unnikrishnan A, Ford MM, Giles CB, Georgescu C, Dozmorov MG, Wren JD, Richardson A, Stanford DR, Freeman WM. Sexually divergent DNA methylation patterns with hippocampal aging. Aging Cell 2017; 16:1342-1352. [PMID: 28948711 PMCID: PMC5676057 DOI: 10.1111/acel.12681] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/13/2017] [Indexed: 01/08/2023] Open
Abstract
DNA methylation is a central regulator of genome function, and altered methylation patterns are indicative of biological aging and mortality. Age‐related cellular, biochemical, and molecular changes in the hippocampus lead to cognitive impairments and greater vulnerability to neurodegenerative disease that varies between the sexes. The role of hippocampal epigenomic changes with aging in these processes is unknown as no genome‐wide analyses of age‐related methylation changes have considered the factor of sex in a controlled animal model. High‐depth, genome‐wide bisulfite sequencing of young (3 month) and old (24 month) male and female mouse hippocampus revealed that while total genomic methylation amounts did not change with aging, specific sites in CG and non‐CG (CH) contexts demonstrated age‐related increases or decreases in methylation that were predominantly sexually divergent. Differential methylation with age for both CG and CH sites was enriched in intergenic and intronic regions and under‐represented in promoters, CG islands, and specific enhancer regions in both sexes, suggesting that certain genomic elements are especially labile with aging, even if the exact genomic loci altered are predominantly sex‐specific. Lifelong sex differences in autosomal methylation at CG and CH sites were also observed. The lack of genome‐wide hypomethylation, sexually divergent aging response, and autosomal sex differences at CG sites was confirmed in human data. These data reveal sex as a previously unappreciated central factor of hippocampal epigenomic changes with aging. In total, these data demonstrate an intricate regulation of DNA methylation with aging by sex, cytosine context, genomic location, and methylation level.
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Affiliation(s)
- Dustin R. Masser
- Reynolds Oklahoma Center on Aging Oklahoma OK USA
- Department of Physiology University of Oklahoma Health Sciences Center Oklahoma OK USA
- Oklahoma Nathan Shock Center for Aging Oklahoma OK USA
| | - Niran Hadad
- Reynolds Oklahoma Center on Aging Oklahoma OK USA
- Oklahoma Nathan Shock Center for Aging Oklahoma OK USA
- Oklahoma Center for Neuroscience University of Oklahoma Health Sciences Center Oklahoma OK USA
| | - Hunter L. Porter
- Reynolds Oklahoma Center on Aging Oklahoma OK USA
- Oklahoma Nathan Shock Center for Aging Oklahoma OK USA
- Oklahoma Center for Neuroscience University of Oklahoma Health Sciences Center Oklahoma OK USA
| | - Colleen A. Mangold
- Department of Biochemistry and Molecular Biology Pennsylvania State University University Park PA USA
| | - Archana Unnikrishnan
- Reynolds Oklahoma Center on Aging Oklahoma OK USA
- Oklahoma Nathan Shock Center for Aging Oklahoma OK USA
- Department of Geriatric Medicine University of Oklahoma Health Sciences Center Oklahoma OK USA
| | - Matthew M. Ford
- Division of Neuroscience Oregon National Primate Research Center Beaverton OR USA
| | - Cory B. Giles
- Arthritis & Clinical Immunology Program Oklahoma Medical Research Foundation Oklahoma OK USA
| | - Constantin Georgescu
- Arthritis & Clinical Immunology Program Oklahoma Medical Research Foundation Oklahoma OK USA
| | - Mikhail G. Dozmorov
- Department of Biostatistics Virginia Commonwealth University School of Medicine Richmond VA USA
| | - Jonathan D. Wren
- Oklahoma Nathan Shock Center for Aging Oklahoma OK USA
- Arthritis & Clinical Immunology Program Oklahoma Medical Research Foundation Oklahoma OK USA
- Department of Biochemistry and Molecular Biology University of Oklahoma Health Sciences Center Oklahoma OK USA
| | - Arlan Richardson
- Reynolds Oklahoma Center on Aging Oklahoma OK USA
- Department of Physiology University of Oklahoma Health Sciences Center Oklahoma OK USA
- Oklahoma Nathan Shock Center for Aging Oklahoma OK USA
- Department of Geriatric Medicine University of Oklahoma Health Sciences Center Oklahoma OK USA
- Oklahoma City VA Medical Center Oklahoma OK USA
| | - David R. Stanford
- Reynolds Oklahoma Center on Aging Oklahoma OK USA
- Department of Physiology University of Oklahoma Health Sciences Center Oklahoma OK USA
- Oklahoma Nathan Shock Center for Aging Oklahoma OK USA
| | - Willard M. Freeman
- Reynolds Oklahoma Center on Aging Oklahoma OK USA
- Department of Physiology University of Oklahoma Health Sciences Center Oklahoma OK USA
- Oklahoma Nathan Shock Center for Aging Oklahoma OK USA
- Oklahoma Center for Neuroscience University of Oklahoma Health Sciences Center Oklahoma OK USA
- Department of Geriatric Medicine University of Oklahoma Health Sciences Center Oklahoma OK USA
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212
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Impact of DNA methylation programming on normal and pre-leukemic hematopoiesis. Semin Cancer Biol 2017; 51:89-100. [PMID: 28964938 DOI: 10.1016/j.semcancer.2017.09.008] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Revised: 09/22/2017] [Accepted: 09/25/2017] [Indexed: 12/30/2022]
Abstract
Epigenome regulation is a critical mechanism that governs cell identity, lineage specification and developmental cell fates. With the advent of low-input and single-cell technologies as well as sophisticated cell labeling techniques, our understanding of transcriptional and epigenetic regulation of hematopoiesis is currently undergoing dramatic changes. Increasingly, evidence suggests that the epigenome conformation acts as a critical decision-making mechanism that instructs self-renewal, differentiation and developmental fates of hematopoietic progenitor cells. When dysregulated, this leads to the evolution of disease states such as leukemia. Indeed, aberrations in DNA methylation, histone modifications and genome architecture are characteristic features of many hematopoietic neoplasms in which epigenetic enzymes are frequently mutated. Sequencing studies and characterization of the epigenetic landscape in lymphomas, leukemias and in aged healthy individuals with clonal hematopoiesis have been indispensible to identify epigenetic regulators that play a role in transformation or pre-disposition to hematopoietic malignancies. In this review, we outline the current view of the hematopoietic system and the epigenetic mechanisms regulating hematopoiesis under homeostatic conditions, with a particular focus on the role of DNA methylation in this process. We will also summarize the current knowledge on the mechanisms underlying dysregulated DNA methylation in hematologic malignancies and how this contributes to our understanding of the physiological functions of epigenetic regulators in hematopoiesis.
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213
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De Paoli-Iseppi R, Deagle BE, McMahon CR, Hindell MA, Dickinson JL, Jarman SN. Measuring Animal Age with DNA Methylation: From Humans to Wild Animals. Front Genet 2017; 8:106. [PMID: 28878806 PMCID: PMC5572392 DOI: 10.3389/fgene.2017.00106] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Accepted: 08/02/2017] [Indexed: 01/19/2023] Open
Abstract
DNA methylation (DNAm) is a key mechanism for regulating gene expression in animals and levels are known to change with age. Recent studies have used DNAm changes as a biomarker to estimate chronological age in humans and these techniques are now also being applied to domestic and wild animals. Animal age is widely used to track ongoing changes in ecosystems, however chronological age information is often unavailable for wild animals. An ability to estimate age would lead to improved monitoring of (i) population trends and status and (ii) demographic properties such as age structure and reproductive performance. Recent studies have revealed new examples of DNAm age association in several new species increasing the potential for developing DNAm age biomarkers for a broad range of wild animals. Emerging technologies for measuring DNAm will also enhance our ability to study age-related DNAm changes and to develop new molecular age biomarkers.
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Affiliation(s)
- Ricardo De Paoli-Iseppi
- Institute for Marine and Antarctic Studies, University of TasmaniaHobart, TAS, Australia.,Australian Antarctic DivisionHobart, TAS, Australia
| | | | | | - Mark A Hindell
- Institute for Marine and Antarctic Studies, University of TasmaniaHobart, TAS, Australia
| | - Joanne L Dickinson
- Cancer, Genetics and Immunology Group, Menzies Institute for Medical ResearchHobart, TAS, Australia
| | - Simon N Jarman
- Trace and Environmental DNA Laboratory, Department of Environment and Agriculture, Curtin UniversityPerth, WA, Australia.,CSIRO Indian Ocean Marine Research Centre, University of Western AustraliaPerth, WA, Australia
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Abstract
Epigenetic clocks provide powerful tools to evaluate nutritional, hormonal, and genetic effects on aging. What can we learn from differences between species in how these clocks tick? Please see related Research articles: http://genomebiology.biomedcentral.com/articles/10.1186/s13059-017-1203-5, http://genomebiology.biomedcentral.com/articles/10.1186/s13059-017-1186-2, http://genomebiology.biomedcentral.com/articles/10.1186/s13059-017-1187-1 and http://genomebiology.biomedcentral.com/articles/10.1186/s13059-017-1185-3
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Affiliation(s)
- Wolfgang Wagner
- Helmholtz-Institute for Biomedical Engineering, Stem Cell Biology and Cellular Engineering, University Hospital of the RWTH Aachen, 52074, Aachen, Germany. .,Institute for Biomedical Engineering - Cell Biology, University Hospital of the RWTH Aachen, 52074, Aachen, Germany.
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