Project description:Various risk factors in aging contribute to the pathogenesis of frailty. Epigenetic changes are among the factors that influence gene expression. It plays a role in regulating the immune system during aging, especially DNA methylation. DNA methylation profiles in the elderly have been widely studied. However, the differences in methylation patterns between robust and frail aging populations remain underexplored. A total of 32 subjects were recruited (age ≥ 65 years old) , consisting of 16 as the frail group and 16 as the robust group. For further methylation sequencing, only one robust subject and four frail subjects were selected. The selection of these individuals was based on their TNF-α concentrations, representing one subject with the lowest and four with the highest TNF-α levels. In this study, we identified an association between altered DNA methylation patterns, mRNA expression levels, and inflammatory conditions in frail elderly. The differential expression of certain genes is likely influenced by differences in methylation level between the frail and robust groups. In overall methylation, the differential of 5mC was slightly significant (p=0.06), while 5hmC was not significantly different (p=0.53). We aim to investigate these differences to gain a deeper understanding of the pathogenesis of frailty in some specific genes.
Project description:Illumina Infinium EPIC HumanMethylation BeadChip data from saliva DNA samples from a healthy elderly cohort with individuals in the age range 70-95 in Southwest Sweden. The cohort was stratified into study groups based on participants´answers to a questionnaire of different lifestyle factors including vitamin supplementations, smoking and drinking habits, physical activity (per year), sun exposure and eating habits. Vitamin D intake was evaluated from the vitamin D supplementation (alone or in a multivitamin complex), dietary vitamin D intake (fish and seafood frequency) and vitamin D synthesis in the skin (sunlight exposure and use of sunscreen). Differential methylation analysis was performed for all the study groups and the combination of different factors with vitamin D supplementation. Gender, age, smoking and alcohol (SD and frequency) were used as covariates in the analyses. Only the study groups referred to the conclusions of the study are shown.
Project description:DNA methylation levels in whole blood measured over a ten years follow up in an elderly birth cohort of 86 samples For each sample, whole blood was drawn in year 1997 and in year 2007 Follow-up design: Same participant was measured over time in 1997 and 2007
Project description:The data contains Illumina 450k/EPIC array methylation files from 104 patients of the NOA-08 study comparing temozolomide alone vs. radiotherapy in elderly patients with glioblastoma
Project description:Folate, and its synthetic form folic acid, function as donor of one-carbon units and have been, together with other B-vitamins, implicated in programming of epigenetic processes such as DNA methylation during early development. To what extent regulation of DNA methylation can be altered via B-vitamins later in life, and how this relates to health and disease, is not exactly known. The aim of this study was to identify effects of long-term supplementation with folic acid and vitamin B12 on genome-wide DNA methylation in elderly subjects. This project was part of a randomized, placebo-controlled trial on effects of supplemental intake of folic acid and vitamin B12 on bone fracture incidence (B-PROOF study). Participants with mildly elevated homocysteine levels, aged 65-75 years, were randomly assigned to take 400 µg folic acid and 500 µg vitamin B12 per day or a placebo during an intervention period of two years. DNA was isolated from buffy coats, collected before and after intervention, and genome-wide DNA methylation was determined in 87 participants (n=44 folic acid/vitamin B12, n=43 placebo) using the Infinium HumanMethylation450 BeadChip. After intervention with folic acid and vitamin B12, 162 (versus 14 in the placebo group) of the 431,312 positions were differentially methylated as compared to baseline. Comparisons of the DNA methylation changes in the participants receiving folic acid and vitamin B12 versus placebo, revealed one single differentially methylated position (cg19380919) with a borderline statistical significance. However, based on the analyses of differentially methylated regions (DMRs) consisting of multiple positions, we identified 6 regions that differed statistically significantly between the intervention and placebo group. Pronounced changes were found for regions in the DIRAS3, ARMC8 and NODAL genes, implicated in carcinogenesis and early embryonic development. Furthermore, serum levels of folate and vitamin B12 or plasma homocysteine were related to DNA methylation of 173, 425 and 11 regions, respectively. Interestingly, for several members of the developmental HOX genes, DNA methylation was related to serum levels of folate. Long-term supplementation with folic acid and vitamin B12 in elderly subjects resulted in effects on DNA methylation of several genes, among which genes implicated in developmental processes.