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- Rönn, Tina, et al.
(författare)
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Circulating triglycerides are associated with human adipose tissue DNA methylation of genes linked to metabolic disease
- 2023
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Ingår i: Human Molecular Genetics. - : Oxford University Press (OUP). - 0964-6906 .- 1460-2083. ; 32:11, s. 1875-1887
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Tidskriftsartikel (refereegranskat)abstract
- Dysregulation of circulating lipids is a central element for the metabolic syndrome. However, it is not well established whether human subcutaneous adipose tissue is affected by or affect circulating lipids through epigenetic mechanisms. Hence, our aim was to investigate the association between circulating lipids and DNA methylation levels in human adipose tissue. DNA methylation and gene expression were analysed genome-wide in subcutaneous adipose tissue from two different cohorts, including 85 men and 93 women, respectively. Associations between DNA methylation and circulating levels of triglycerides, low-density lipoprotein, high-density lipoprotein and total cholesterol were analysed. Causal mediation analyses tested if adipose tissue DNA methylation mediates the effects of triglycerides on gene expression or insulin resistance. We found 115 novel associations between triglycerides and adipose tissue DNA methylation, e.g. in the promoter of RFS1, ARID2 and HOXA5 in the male cohort (P ≤ 1.1 × 10-7), and 63 associations, e.g. within the gene body of PTPRN2 and COL6A3 in the female cohort. We further connected these findings to altered mRNA expression levels in adipose tissue (e.g. HOXA5, IL11 and FAM45B). Interestingly, there was no overlap between methylation sites associated with triglycerides in men and the sites found in women, which points towards sex-specific effects of triglycerides on the epigenome. Finally, a causal mediation analysis provided support for adipose tissue DNA methylation as a partial mediating factor between circulating triglycerides and insulin resistance. This study identified novel epigenetic alterations in adipose tissue associated with circulating lipids. Identified epigenetic changes seem to mediate effects of triglycerides on insulin resistance.
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| 2. |
- Rönn, Tina, et al.
(författare)
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Impact of age, BMI and HbA1c levels on the genome-wide DNA methylation and mRNA expression patterns in human adipose tissue and identification of epigenetic biomarkers in blood.
- 2015
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Ingår i: Human Molecular Genetics. - : Oxford University Press (OUP). - 0964-6906 .- 1460-2083. ; 24:13, s. 3792-3813
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Tidskriftsartikel (refereegranskat)abstract
- Increased age, BMI and HbA1c levels are risk factors for several non-communicable diseases. However, the impact of these factors on the genome-wide DNA methylation pattern in human adipose tissue remains unknown. We analyzed DNA methylation of ∼480,000 sites in human adipose tissue from 96 males and 94 females, and related methylation to age, BMI and HbA1c. We also compared epigenetic signatures in adipose tissue and blood. Age was significantly associated with both altered DNA methylation and expression of 1,050 genes (e.g. FHL2, NOX4 and PLG). Interestingly, many reported epigenetic biomarkers of ageing in blood, including ELOVL2, FHL2, KLF14 and GLRA1, also showed significant correlations between adipose tissue DNA methylation and age in our study. The most significant association between age and adipose tissue DNA methylation was found upstream of ELOVL2. We identified 2,825 genes (e.g. FTO, ITIH5, CCL18, MTCH2, IRS1 and SPP1) where both DNA methylation and expression correlated with BMI. Methylation at previously reported HIF3A sites correlated significantly with BMI in females only. HbA1c (range 28-46 mmol/mol) correlated significantly with methylation of 711 sites, annotated to e.g. RAB37, TICAM1 and HLA-DPB1. Pathway analyses demonstrated that methylation levels associated with age and BMI are overrepresented among genes involved in cancer, type 2 diabetes and cardiovascular disease. Our results highlight the impact of age, BMI and HbA1c on epigenetic variation of candidate genes for metabolic diseases and cancer in human adipose tissue. Importantly, we demonstrate that epigenetic biomarkers in blood can mirror age-related epigenetic signatures in target tissues for metabolic diseases such as adipose tissue.
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