Using epigenome-wide association scans of DNA methylation in age-related complex human traits

Epigenomics ◽  
2012 ◽  
Vol 4 (5) ◽  
pp. 511-526 ◽  
Author(s):  
Pei-Chien Tsai ◽  
Tim D Spector ◽  
Jordana T Bell
2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Jack Hearn ◽  
Fiona Plenderleith ◽  
Tom J. Little

Abstract Background Patterns of methylation influence lifespan, but methylation and lifespan may also depend on diet, or differ between genotypes. Prior to this study, interactions between diet and genotype have not been explored together to determine their influence on methylation. The invertebrate Daphnia magna is an excellent choice for testing the epigenetic response to the environment: parthenogenetic offspring are identical to their siblings (making for powerful genetic comparisons), they are relatively short lived and have well-characterised inter-strain life-history trait differences. We performed a survival analysis in response to caloric restriction and then undertook a 47-replicate experiment testing the DNA methylation response to ageing and caloric restriction of two strains of D. magna. Results Methylated cytosines (CpGs) were most prevalent in exons two to five of gene bodies. One strain exhibited a significantly increased lifespan in response to caloric restriction, but there was no effect of food-level CpG methylation status. Inter-strain differences dominated the methylation experiment with over 15,000 differently methylated CpGs. One gene, Me31b, was hypermethylated extensively in one strain and is a key regulator of embryonic expression. Sixty-one CpGs were differentially methylated between young and old individuals, including multiple CpGs within the histone H3 gene, which were hypermethylated in old individuals. Across all age-related CpGs, we identified a set that are highly correlated with chronological age. Conclusions Methylated cytosines are concentrated in early exons of gene sequences indicative of a directed, non-random, process despite the low overall DNA methylation percentage in this species. We identify no effect of caloric restriction on DNA methylation, contrary to our previous results, and established impacts of caloric restriction on phenotype and gene expression. We propose our approach here is more robust in invertebrates given genome-wide CpG distributions. For both strain and ageing, a single gene emerges as differentially methylated that for each factor could have widespread phenotypic effects. Our data showed the potential for an epigenetic clock at a subset of age positions, which is exciting but requires confirmation.


2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Katherine R. Dobbs ◽  
Paula Embury ◽  
Emmily Koech ◽  
Sidney Ogolla ◽  
Stephen Munga ◽  
...  

Abstract Background Age-related changes in adaptive and innate immune cells have been associated with a decline in effective immunity and chronic, low-grade inflammation. Epigenetic, transcriptional, and functional changes in monocytes occur with aging, though most studies to date have focused on differences between young adults and the elderly in populations with European ancestry; few data exist regarding changes that occur in circulating monocytes during the first few decades of life or in African populations. We analyzed DNA methylation profiles, cytokine production, and inflammatory gene expression profiles in monocytes from young adults and children from western Kenya. Results We identified several hypo- and hyper-methylated CpG sites in monocytes from Kenyan young adults vs. children that replicated findings in the current literature of differential DNA methylation in monocytes from elderly persons vs. young adults across diverse populations. Differentially methylated CpG sites were also noted in gene regions important to inflammation and innate immune responses. Monocytes from Kenyan young adults vs. children displayed increased production of IL-8, IL-10, and IL-12p70 in response to TLR4 and TLR2/1 stimulation as well as distinct inflammatory gene expression profiles. Conclusions These findings complement previous reports of age-related methylation changes in isolated monocytes and provide novel insights into the role of age-associated changes in innate immune functions.


2020 ◽  
Vol 30 (Supplement_5) ◽  
Author(s):  
A Maugeri ◽  
M Barchitta ◽  
G Favara ◽  
C La Mastra ◽  
MC La Rosa ◽  
...  

Abstract Background Social disadvantage and unhealthy lifestyles may induce molecular changes associated with aging and age-related diseases. For instance, previous studies reported socioeconomic difference in DNA methylation, which in turn led to aberrant gene expression and genome instability. Socioeconomic status (SES) alone, however, does not completely explain this difference, and further studies are needed to unveil what factors contribute to it. Methods We conducted a cross-sectional study on 349 Italian women, aged 25-64 years, to assess SES differences in LINE-1 methylation level - a surrogate marker of global DNA methylation - and to examine the mediating effect of lifestyles (i.e. diet, smoking habits, physical activity, and weight status). Educational level was used as SES indicator. The adherence to Mediterranean diet (MD) was assessed by the Mediterranean Diet Score (MDS). Leukocyte LINE-1 methylation was assessed by pyrosequencing. Mediation analysis was conducted using the PROCESS macro for the SPSS software. Results We first observed that women with high educational level were more likely to be normal weight (p < 0.001) and to adhere to MD (p = 0.018), and less likely to perform physical activity (p = 0.012) than their less educated counterpart. Moreover, age-adjusted linear regression demonstrated that LINE-1 methylation level increased with increasing educational level (β = 0.016; SE = 0.003; p < 0.001). In line, mediation analysis demonstrated an indirect effect of high educational level on LINE-1 methylation through the adherence to MD (β = 0.003; 95%CI=0.001-0.006). Specifically, the mediator could account for 9.5% of the total effect. None of the other lifestyles, instead, exhibited a significant mediating effect. Conclusions To our knowledge, this is the first study demonstrating the mediation of diet in the relationship between SES and DNA methylation. Thus, our findings add even more value to the promotion of healthy dietary habits among social disadvantaged people. Key messages Social disadvantage is associated with epigenetic changes related to aging and age-related diseases. Adherence to the Mediterranean diet might mediate the association between socioeconomic status and DNA methylation.


Genes ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 870
Author(s):  
Jiansheng Zhang ◽  
Hongli Fu ◽  
Yan Xu

In recent years, scientists have found a close correlation between DNA methylation and aging in epigenetics. With the in-depth research in the field of DNA methylation, researchers have established a quantitative statistical relationship to predict the individual ages. This work used human blood tissue samples to study the association between age and DNA methylation. We built two predictors based on healthy and disease data, respectively. For the health data, we retrieved a total of 1191 samples from four previous reports. By calculating the Pearson correlation coefficient between age and DNA methylation values, 111 age-related CpG sites were selected. Gradient boosting regression was utilized to build the predictive model and obtained the R2 value of 0.86 and MAD of 3.90 years on testing dataset, which were better than other four regression methods as well as Horvath’s results. For the disease data, 354 rheumatoid arthritis samples were retrieved from a previous study. Then, 45 CpG sites were selected to build the predictor and the corresponded MAD and R2 were 3.11 years and 0.89 on the testing dataset respectively, which showed the robustness of our predictor. Our results were better than the ones from other four regression methods. Finally, we also analyzed the twenty-four common CpG sites in both healthy and disease datasets which illustrated the functional relevance of the selected CpG sites.


Thorax ◽  
2020 ◽  
pp. thoraxjnl-2020-215866
Author(s):  
Ana I Hernandez Cordero ◽  
Chen Xi Yang ◽  
Maen Obeidat ◽  
Julia Yang ◽  
Julie MacIsaac ◽  
...  

IntroductionPeople living with HIV (PLWH) suffer from age-related comorbidities such as COPD. The processes responsible for reduced lung function in PLWH are largely unknown. We performed an epigenome-wide association study to investigate whether blood DNA methylation is associated with impaired lung function in PLWH.MethodsUsing blood DNA methylation profiles from 161 PLWH, we tested the effect of methylation on FEV1, FEV1/FVC ratio and FEV1 decline over a median of 5 years. We evaluated the global methylation of PLWH with airflow obstruction by testing the differential methylation of transposable elements Alu and LINE-1, a well-described marker of epigenetic ageing.ResultsAirflow obstruction as defined by a FEV1/FVC<0.70 was associated with 1393 differentially methylated positions (DMPs), while 4676 were associated with airflow obstruction based on the FEV1/FVC<lower limit of normal. These DMPs were enriched for biological pathways associated with chronic viral infections. The airflow obstruction group was globally hypomethylated compared with those without airflow obstruction. 103 and 7112 DMPs were associated with FEV1 and FEV1/FVC, respectively. No positions were associated with FEV1 decline.ConclusionA large number of DMPs were associated with airflow obstruction and lung function in a unique cohort of PLWH. Airflow obstruction in even relatively young PLWH is associated with global hypomethylation, suggesting advanced epigenetic ageing compared with those with normal lung function. The disturbance of the epigenetic regulation of key genes not previously identified in non-HIV COPD cohorts could explain the unique risk of COPD in PLWH.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Oladele A. Oluwayiose ◽  
Haotian Wu ◽  
Hachem Saddiki ◽  
Brian W. Whitcomb ◽  
Laura B. Balzer ◽  
...  

AbstractParental age at time of offspring conception is increasing in developed countries. Advanced male age is associated with decreased reproductive success and increased risk of adverse neurodevelopmental outcomes in offspring. Mechanisms for these male age effects remain unclear, but changes in sperm DNA methylation over time is one potential explanation. We assessed genome-wide methylation of sperm DNA from 47 semen samples collected from male participants of couples seeking infertility treatment. We report that higher male age was associated with lower likelihood of fertilization and live birth, and poor embryo development (p < 0.05). Furthermore, our multivariable linear models showed male age was associated with alterations in sperm methylation at 1698 CpGs and 1146 regions (q < 0.05), which were associated with > 750 genes enriched in embryonic development, behavior and neurodevelopment among others. High dimensional mediation analyses identified four genes (DEFB126, TPI1P3, PLCH2 and DLGAP2) with age-related sperm differential methylation that accounted for 64% (95% CI 0.42–0.86%; p < 0.05) of the effect of male age on lower fertilization rate. Our findings from this modest IVF population provide evidence for sperm methylation as a mechanism of age-induced poor reproductive outcomes and identifies possible candidate genes for mediating these effects.


2021 ◽  
Vol 23 (1) ◽  
Author(s):  
Shoghag Panjarian ◽  
Jozef Madzo ◽  
Kelsey Keith ◽  
Carolyn M. Slater ◽  
Carmen Sapienza ◽  
...  

Abstract Background DNA methylation alterations have similar patterns in normal aging tissue and in cancer. In this study, we investigated breast tissue-specific age-related DNA methylation alterations and used those methylation sites to identify individuals with outlier phenotypes. Outlier phenotype is identified by unsupervised anomaly detection algorithms and is defined by individuals who have normal tissue age-dependent DNA methylation levels that vary dramatically from the population mean. Methods We generated whole-genome DNA methylation profiles (GSE160233) on purified epithelial cells and used publicly available Infinium HumanMethylation 450K array datasets (TCGA, GSE88883, GSE69914, GSE101961, and GSE74214) for discovery and validation. Results We found that hypermethylation in normal breast tissue is the best predictor of hypermethylation in cancer. Using unsupervised anomaly detection approaches, we found that about 10% of the individuals (39/427) were outliers for DNA methylation from 6 DNA methylation datasets. We also found that there were significantly more outlier samples in normal-adjacent to cancer (24/139, 17.3%) than in normal samples (15/228, 5.2%). Additionally, we found significant differences between the predicted ages based on DNA methylation and the chronological ages among outliers and not-outliers. Additionally, we found that accelerated outliers (older predicted age) were more frequent in normal-adjacent to cancer (14/17, 82%) compared to normal samples from individuals without cancer (3/17, 18%). Furthermore, in matched samples, we found that the epigenome of the outliers in the pre-malignant tissue was as severely altered as in cancer. Conclusions A subset of patients with breast cancer has severely altered epigenomes which are characterized by accelerated aging in their normal-appearing tissue. In the future, these DNA methylation sites should be studied further such as in cell-free DNA to determine their potential use as biomarkers for early detection of malignant transformation and preventive intervention in breast cancer.


2018 ◽  
Vol 9 (1) ◽  
pp. 190-202 ◽  
Author(s):  
Leonidas Chouliaras ◽  
Roy Lardenoije ◽  
Gunter Kenis ◽  
Diego Mastroeni ◽  
Patrick R. Hof ◽  
...  

Abstract Brain aging has been associated with aberrant DNA methylation patterns, and changes in the levels of DNA methylation and associated markers have been observed in the brains of Alzheimer’s disease (AD) patients. DNA hydroxymethylation, however, has been sparsely investigated in aging and AD. We have previously reported robust decreases in 5-methylcytosine (5-mC) and 5-hydroxymethylcytosine (5-hmC) in the hippocampus of AD patients compared to non-demented controls. In the present study, we investigated 3- and 9-month-old APPswe/PS1ΔE9 transgenic and wild-type mice for possible age-related alterations in 5-mC and 5-hmC levels in three hippocampal sub-regions using quantitative immunohistochemistry. While age-related increases in levels of both 5-mC and 5-hmC were found in wild-type mice, APPswe/PS1ΔE9 mice showed decreased levels of 5-mC at 9 months of age and no age-related changes in 5-hmC throughout the hippocampus. Altogether, these findings suggest that aberrant amyloid processing impact on the balance between DNA methylation and hydroxymethylation in the hippocampus during aging in mice.


2021 ◽  
Vol 13 ◽  
Author(s):  
Pei-Lun Kuo ◽  
Ann Zenobia Moore ◽  
Frank R. Lin ◽  
Luigi Ferrucci

Objectives: Age-related hearing loss (ARHL) is highly prevalent among older adults, but the potential mechanisms and predictive markers for ARHL are lacking. Epigenetic age acceleration has been shown to be predictive of many age-associated diseases and mortality. However, the association between epigenetic age acceleration and hearing remains unknown. Our study aims to investigate the relationship between epigenetic age acceleration and audiometric hearing in the Baltimore Longitudinal Study of Aging (BLSA).Methods: Participants with both DNA methylation and audiometric hearing measurements were included. The main independent variables are epigenetic age acceleration measures, including intrinsic epigenetic age acceleration—“IEAA,” Hannum age acceleration—“AgeAccelerationResidualHannum,” PhenoAge acceleration—“AgeAccelPheno,” GrimAge acceleration—“AgeAccelGrim,” and methylation-based pace of aging estimation—“DunedinPoAm.” The main dependent variable is speech-frequency pure tone average. Linear regression was used to assess the association between epigenetic age acceleration and hearing.Results: Among the 236 participants (52.5% female), after adjusting for age, sex, race, time difference between measurements, cardiovascular factors, and smoking history, the effect sizes were 0.11 995% CI: (–0.00, 0.23), p = 0.054] for Hannum’s clock, 0.08 [95% CI: (–0.03, 0.19), p = 0.143] for Horvath’s clock, 0.10 [95% CI: (–0.01, 0.21), p = 0.089] for PhenoAge, 0.20 [95% CI: (0.06, 0.33), p = 0.004] for GrimAge, and 0.21 [95% CI: (0.09, 0.33), p = 0.001] for DunedinPoAm.Discussion: The present study suggests that some epigenetic age acceleration measurements are associated with hearing. Future research is needed to study the potential subclinical cardiovascular causes of hearing and to investigate the longitudinal relationship between DNA methylation and hearing.


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