scholarly journals Creating and validating a DNA methylation-based proxy for Interleukin-6

2020 ◽  
Author(s):  
Anna J Stevenson ◽  
Danni A Gadd ◽  
Robert Francis Hillary ◽  
Daniel L. McCartney ◽  
Archie Campbell ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Cognitive Functioning ◽  
Cognitive Ability ◽  
Chronic Inflammation ◽  
Interleukin 6 ◽  
Epigenetic Mechanism ◽  
Inverse Association ◽  
Age Related ◽  
Independent Test ◽  
Methylation Score

Chronic inflammation is a pervasive feature of ageing and may be linked to age-related cognitive decline. However, population studies evaluating its relationship with cognitive functioning have produced heterogeneous results. A potential reason for this is the variability of inflammatory mediators which could lead to misclassifications of individuals' persisting levels of inflammation. The epigenetic mechanism DNA methylation has shown utility in indexing environmental exposures and could potentially be leveraged to provide proxy signatures of chronic inflammation. We conducted an elastic net regression of interleukin-6 (IL-6) in a cohort of 895 older adults (mean age: 69 years) to develop a DNA methylation-based predictor. The predictor was tested in an independent cohort (n=7,028 [417 with measured IL-6], mean age: 51 years).We examined the association between the DNA methylation IL-6 score and serum IL-6, its association with age and established correlates of circulating IL-6, and with cognitive ability. A weighted score from 12 DNA methylation sites optimally predicted IL-6 (independent test set R2=5.1%). In the independent test cohort, both measured IL-6, and the DNA methylation proxy, increased as a function of age (serum IL-6: n=417, β=0.02, SE=0.004 p=1.3x10-7; DNAm IL-6 score: n=7,028, β=0.02, SE=0.0009, p<2x10-16). Serum IL-6 was not found to associate with cognitive ability (n=417, β=-0.06, SE=0.05, p=0.19); however, an inverse association was identified between the DNA methylation score and cognitive functioning (n=7,028, β=-0.14, SE=0.02, pFDR=1.5x10-14). These results suggest DNA methylation-based predictors can be used as proxies for inflammatory markers, potentially allowing for reliable insights into the relationship between chronic inflammation and pertinent health outcomes.

scholarly journals Creating and Validating a DNA Methylation-Based Proxy for Interleukin-6

2021 ◽  
Author(s):  
Anna J Stevenson ◽  
Danni A Gadd ◽  
Robert F Hillary ◽  
Daniel L McCartney ◽  
Archie Campbell ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Cognitive Functioning ◽  
Chronic Inflammation ◽  
Interleukin 6 ◽  
Inverse Association ◽  
Generation Scotland ◽  
Independent Test ◽  
Lothian Birth Cohort ◽  
Weighted Score ◽  
The Relationship

Abstract Background Studies evaluating the relationship between chronic inflammation and cognitive functioning have produced heterogeneous results. A potential reason for this is the variability of inflammatory mediators which could lead to misclassifications of individuals’ persisting levels of inflammation. DNA methylation (DNAm) has shown utility in indexing environmental exposures and could be leveraged to provide proxy signatures of chronic inflammation. Method We conducted an elastic net regression of interleukin-6 (IL-6) in a cohort of 875 older adults (Lothian Birth Cohort 1936; mean age: 70 years) to develop a DNAm-based predictor. The predictor was tested in an independent cohort (Generation Scotland; N = 7028 [417 with measured IL-6], mean age: 51 years). Results A weighted score from 35 CpG sites optimally predicted IL-6 in the independent test set (Generation Scotland; R2 = 4.4%, p = 2.1 × 10−5). In the independent test cohort, both measured IL-6 and the DNAm proxy increased with age (serum IL-6: n = 417, β = 0.02, SE = 0.004, p = 1.3 × 10−7; DNAm IL-6 score: N = 7028, β = 0.02, SE = 0.0009, p &lt; 2 × 10−16). Serum IL-6 did not associate with cognitive ability (n = 417, β = −0.06, SE = 0.05, p = .19); however, an inverse association was identified between the DNAm score and cognitive functioning (N = 7028, β = −0.16, SE = 0.02, pFDR &lt; 2 × 10−16). Conclusions These results suggest methylation-based predictors can be used as proxies for inflammatory markers, potentially allowing for further insight into the relationship between inflammation and pertinent health outcomes.

scholarly journals An epigenetic predictor of death captures multi-modal measures of brain health

2019 ◽  
Author(s):  
Robert F. Hillary ◽  
Anna J. Stevenson ◽  
Simon R. Cox ◽  
Daniel L. McCartney ◽  
Sarah E. Harris ◽  
...  
Keyword(s):  
Cognitive Ability ◽  
Epigenetic Mechanism ◽  
Vascular Lesions ◽  
Epigenetic Clock ◽  
General Cognitive Ability ◽  
Brain Health ◽  
Standard Deviation Increase ◽  
Brain White Matter ◽  
Age Related ◽  
Lothian Birth Cohort

AbstractIndividuals of the same chronological age exhibit disparate rates of biological ageing. Consequently, a number of methodologies have been proposed to determine biological age and primarily exploit variation at the level of DNA methylation (DNAm) – a commonly studied epigenetic mechanism. A novel epigenetic clock, termed ‘DNAm GrimAge’ has outperformed its predecessors in predicting the risk of mortality as well as a number of age-related morbidities. However, the association between DNAm GrimAge and cognitive or neuroimaging phenotypes remains unknown. We explore these associations in the Lothian Birth Cohort 1936 (n=709, mean age 73 years). Higher DNAm GrimAge was strongly associated with all-cause mortality over twelve years of follow-up (Hazard Ratio per standard deviation increase in GrimAge: 1.81, P < 2.0 × 10-16). Higher DNAm GrimAge was associated with lower age 11 IQ (β=-0.11), lower age 73 general cognitive ability (β=-0.18), decreased brain volume (β=-0.25) and increased brain white matter hyperintensities (β=0.17). Sixty-eight of 137 health- and brain-related phenotypes tested were significantly associated with DNAm GrimAge. Adjusting all models for childhood cognitive ability attenuated to non-significance a small number of associations (12/68 associations; 6 of which were cognitive traits), but not the association with general cognitive ability (33.9% attenuation). Higher DNAm GrimAge cross-sectionally associates with lower cognitive ability and brain vascular lesions in older age, independently of early life cognitive ability. Thus, this epigenetic predictor of mortality is also associated with multiple different measures of brain health and may aid in the prediction of age-related cognitive decline.

scholarly journals Characterisation of an inflammation-related epigenetic score and its association with cognitive ability

2019 ◽  
Author(s):  
Anna J. Stevenson ◽  
Daniel L. McCartney ◽  
Robert F. Hillary ◽  
Archie Campbell ◽  
Stewart W. Morris ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Cognitive Ability ◽  
Chronic Inflammation ◽  
Birth Cohort ◽  
Large Scale ◽  
Acute Infection ◽  
Plasma Concentrations ◽  
Generation Scotland ◽  
Lothian Birth Cohort ◽  
Serum Crp

ABSTRACTResults from large cohort studies investigating the association between inflammation and cognition have been mixed, possibly due to methodological disparities. However, a key issue in research utilising inflammatory biomarkers is their typically phasic responses. C-reactive protein (CRP) is widely used to investigate the association between chronic inflammation and cognition, but its plasma concentrations can markedly deviate in response to acute infection. Recently a large-scale epigenome-wide association study identified DNA methylation correlates of CRP. DNA methylation is thought to be relatively stable in the short term, marking it as a potentially useful signature of exposure. Here, we generate an epigenetic CRP score and investigate its trajectories with age, and associations with cognitive ability, in comparison to serum CRP in two cohorts: a longitudinal study of older adults (the Lothian Birth Cohort 1936, n=889) and a large, cross-sectional cohort (Generation Scotland, n=7,028).We identified differing trajectories of serum CRP across the cohorts, with no homogeneous trends seen with age. Conversely, the epigenetic score was consistently found to increase with age, and to do so more rapidly in males compared to females. Higher levels of serum CRP were found to associate with poorer cognition in Lothian Birth Cohort 1936, but not in Generation Scotland. However, a consistent negative association was identified between cognition and the epigenetic score in both cohorts. Furthermore, the epigenetic score accounted for a greater proportion of variance in cognitive ability.Our results suggest that epigenetic signatures of acute inflammatory markers may provide an enhanced signature of chronic inflammation, allowing for more reliable stratification of individuals, and thus clearer inference of associations with incident health outcomes.

scholarly journals Distinct DNA methylation targets by aging and chronic inflammation: a pilot study using gastric mucosa infected with Helicobacter pylori

2019 ◽  
Vol 11 (1) ◽  
Author(s):  
Satoshi Yamashita ◽  
Sohachi Nanjo ◽  
Emil Rehnberg ◽  
Naoko Iida ◽  
Hideyuki Takeshima ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Helicobacter Pylori ◽  
Gastric Mucosa ◽  
Chronic Inflammation ◽  
Cpg Islands ◽  
Human Gastric Mucosa ◽  
Driver Genes ◽  
Age Related ◽  
A Genome ◽  
Aberrant Dna Methylation

Abstract Background Aberrant DNA methylation is induced by aging and chronic inflammation in normal tissues. The induction by inflammation is widely recognized as acceleration of age-related methylation. However, few studies addressed target genomic regions and the responsible factors in a genome-wide manner. Here, we analyzed methylation targets by aging and inflammation, taking advantage of the potent methylation induction in human gastric mucosa by Helicobacter pylori infection-triggered inflammation. Results DNA methylation microarray analysis of 482,421 CpG probes, grouped into 270,249 genomic blocks, revealed that high levels of methylation were induced in 44,461 (16.5%) genomic blocks by inflammation, even after correction of the influence of leukocyte infiltration. A total of 61.8% of the hypermethylation was acceleration of age-related methylation while 21.6% was specific to inflammation. Regions with H3K27me3 were frequently hypermethylated both by aging and inflammation. Basal methylation levels were essential for age-related hypermethylation while even regions with little basal methylation were hypermethylated by inflammation. When limited to promoter CpG islands, being a microRNA gene and high basal methylation levels strongly enhanced hypermethylation while H3K27me3 strongly enhanced inflammation-induced hypermethylation. Inflammation was capable of overriding active transcription. In young gastric mucosae, genes with high expression and frequent mutations in gastric cancers were more frequently methylated than in old ones. Conclusions Methylation by inflammation was not simple acceleration of age-related methylation. Targets of aberrant DNA methylation were different between young and old gastric mucosae, and driver genes were preferentially methylated in young gastric mucosa.

scholarly journals Integrated DNA methylation and gene expression profiling across multiple brain regions implicate novel genes in Alzheimer’s disease

2018 ◽  
Author(s):  
Stephen A. Semick ◽  
Rahul A. Bharadwaj ◽  
Leonardo Collado-Torres ◽  
Ran Tao ◽  
Joo Heon Shin ◽  
...  
Keyword(s):  
Gene Expression ◽  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Dna Methylation ◽  
Neurodegenerative Disorder ◽  
Late Onset ◽  
Brain Regions ◽  
Epigenetic Mechanism ◽  
Novel Genes ◽  
Age Related

AbstractBackgroundLate-onset Alzheimer’s disease (AD) is a complex age-related neurodegenerative disorder that likely involves epigenetic factors. To better understand the epigenetic state associated with AD represented as variation in DNA methylation (DNAm), we surveyed 420,852 DNAm sites from neurotypical controls (N=49) and late-onset AD patients (N=24) across four brain regions (hippocampus, entorhinal cortex, dorsolateral prefrontal cortex and cerebellum).ResultsWe identified 858 sites with robust differential methylation, collectively annotated to 772 possible genes (FDR<5%, within 10kb). These sites were overrepresented in AD genetic risk loci (p=0.00655), and nearby genes were enriched for processes related to cell-adhesion, immunity, and calcium homeostasis (FDR<5%). We analyzed corresponding RNA-seq data to prioritize 130 genes within 10kb of the differentially methylated sites, which were differentially expressed and had expression levels associated with nearby DNAm levels (p<0.05). This validated gene set includes previously reported (e.g. ANK1, DUSP22) and novel genes involved in Alzheimer’s disease, such as ANKRD30B.ConclusionsThese results highlight DNAm changes in Alzheimer’s disease that have gene expression correlates, implicating DNAm as an epigenetic mechanism underlying pathological molecular changes associated with AD. Furthermore, our framework illustrates the value of integrating epigenetic and transcriptomic data for understanding complex disease.

Do age-related changes in DNA methylation play a role in the development of age-related diseases?

2013 ◽  
Vol 41 (3) ◽  
pp. 803-807 ◽  
Author(s):  
Sanne D. van Otterdijk ◽  
John C. Mathers ◽  
Gordon Strathdee
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Cpg Islands ◽  
Large Body ◽  
Epigenetic Mechanism ◽  
Aberrant Methylation ◽  
Gene Promoters ◽  
Cpg Sites ◽  
Pathological Conditions ◽  
Age Related

DNA methylation is an important epigenetic mechanism in mammalian cells. It occurs almost exclusively at CpG sites and has a key role in a number of biological processes. It plays an important part in regulating chromatin structure and has been best studied for its role in controlling gene expression. In particular, hypermethylation of gene promoters which have high levels of CpG sites, known as CpG islands, leads to gene inactivation. In healthy cells, however, it appears that only a small number of genes are controlled through promoter hypermethylation, such as genes on the inactivated X-chromosome or at imprinted loci, and most promoter-associated CpG islands remain methylation-free regardless of gene expression status. However, a large body of evidence has now shown that this protection from methylation not only breaks down in a number of pathological conditions (e.g. cancer), but also already occurs during the normal process of aging. The present review focuses on the methylation changes that occur during healthy aging and during disease development, and the potential links between them. We focus especially on the extent to which the acquisition of aberrant methylation changes during aging could underlie the development of a number of important age-related pathological conditions.

scholarly journals DNA Methylation in Neurodegenerative and Cerebrovascular Disorders

2020 ◽  
Vol 21 (6) ◽  
pp. 2220 ◽  
Author(s):  
Olaia Martínez-Iglesias ◽  
Iván Carrera ◽  
Juan Carlos Carril ◽  
Lucía Fernández-Novoa ◽  
Natalia Cacabelos ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Gene Expression Regulation ◽  
Methylation Status ◽  
Cerebrovascular Disorders ◽  
Cerebrovascular Diseases ◽  
Epigenetic Mechanism ◽  
Mrna Levels ◽  
Serum Samples ◽  
Global Methylation ◽  
Age Related

DNA methylation is an epigenetic mechanism by which methyl groups are added to DNA, playing a crucial role in gene expression regulation. The aim of the present study is to compare methylation status of healthy subjects with that of patients with Alzheimer’s, Parkinson’s or Cerebrovascular diseases. We also analyze methylation status of a transgenic Alzheimer’s disease mouse model (3xTg-AD). Our results show that both global methylation (n = 141) and hydroxymethylation (n = 131) levels are reduced in DNA samples from buffy coats of patients with neurodegenerative disorders and age-related cerebrovascular disease. The importance of methylation and hydroxymethylation reduction is stressed by the finding that DNMT3a mRNA levels are also downregulated in buffy coats of patients with Dementia (n = 25). Global methylation is also reduced in brain, liver and serum samples of 3xTg-AD vs. wild type mice, such as DNMT3a mRNA levels that are also decreased in the brain of 3xTg-AD (n = 10). These results suggest that the use of global methylation and hydroxymethylation levels, together with the study of DNMT3a expression, could be useful as a new diagnostic biomarker for these prevalent disorders.

scholarly journals Socially stratified epigenetic profiles are associated with cognitive functioning in children and adolescents

2021 ◽  
Author(s):  
Laurel Amber Sjodin Raffington ◽  
Peter Tanksley ◽  
Aditi Sabhlok ◽  
Liza Vinnik ◽  
Travis Triplett Mallard ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Cognitive Functioning ◽  
Social Inequality ◽  
Chronic Inflammation ◽  
Social Inequalities ◽  
Surrogate Endpoint ◽  
Biological Aging ◽  
Negative Effects ◽  
Reading And Math ◽  
Perceptual Reasoning

Children's cognitive functioning and educational performance are socially stratified. Social inequality, including classism and racism, may operate partly via epigenetic mechanisms that modulate neurocognitive development. Following preregistered analyses of data from 1,183 8- to 19-year-olds from the Texas Twin Project, we examined whether salivary DNA-methylation measures of inflammation (DNAm-CRP), cognitive functioning (Epigenetic-g), and pace of biological aging (DunedinPoAm) are socially stratified and associated with performance on tests of cognitive functions. We find that children growing up in more disadvantaged families and neighborhoods and children from marginalized racial/ethnic groups exhibit DNA-methylation profiles associated with higher chronic inflammation, lower cognitive functioning, and faster pace of biological aging. These salivary DNA-methylation profiles were associated with processing speed, general executive function, perceptual reasoning, verbal comprehension, reading, and math. Given that the DNA-methylation measures we examined were originally developed in adults, our results suggest that social inequalities may produce in children molecular signatures that, when observed in adults, are associated with chronic inflammation, advanced aging, and reduced cognitive function. Salivary DNA-methylation profiles might be useful as a surrogate endpoint in assessing the effectiveness of psychological and economic interventions that aim to reduce negative effects of childhood social inequality on lifespan development.

scholarly journals An epigenetic proxy of chronic inflammation outperforms serum levels as a biomarker of brain ageing

2020 ◽  
Author(s):  
Eleanor L.S. Conole ◽  
Anna J. Stevenson ◽  
Claire Green ◽  
Sarah E. Harris ◽  
Susana Muñoz Maniega ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Chronic Inflammation ◽  
Later Life ◽  
Serum Levels ◽  
Inverse Association ◽  
Domain Specific ◽  
Reactive Protein ◽  
Inflammatory Status ◽  
Brain Ageing ◽  
Serum Crp

AbstractLow-level chronic inflammation increases with age and is associated with cognitive decline. DNA methylation (DNAm) levels may provide more stable reflections of cumulative inflammatory burden than traditional serum approaches. Using structural and diffusion MRI data from 521 individuals aged 73, we demonstrate that a DNAm proxy of C-Reactive Protein (CRP) shows significantly (on average 6.4-fold) stronger associations with brain structural outcomes than serum CRP. We additionally find that DNAm CRP has an inverse association with global and domain-specific (speed, visuospatial and memory) cognitive functioning, and that brain structure partially mediates this CRP-cognitive association (up to 29.4%), dependent on lifestyle and health factors. These data support the hypothesis that chronic systemic inflammation may contribute to neurodegenerative brain changes which underlie differences in cognitive ability in later life. DNA methylation-based predictors could be used as proxies for chronic inflammatory status.

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