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- Gillberg, Linn, et al.
(författare)
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Adipose tissue transcriptomics and epigenomics in low birthweight men and controls : role of high-fat overfeeding
- 2016
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Ingår i: Diabetologia. - : Springer Science and Business Media LLC. - 0012-186X .- 1432-0428. ; 59:4, s. 799-812
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Tidskriftsartikel (refereegranskat)abstract
- Aims/hypothesis Individuals who had a low birthweight (LBW) are at an increased risk of insulin resistance and type 2 diabetes when exposed to high-fat overfeeding (HFO). We studied genome-wide mRNA expression and DNA methylation in subcutaneous adipose tissue (SAT) after 5 days of HFO and after a control diet in 40 young men, of whom 16 had LBW. Methods mRNA expression was analysed using Affymetrix Human Gene 1.0 ST arrays and DNA methylation using Illumina 450K BeadChip arrays. Results We found differential DNA methylation at 53 sites in SAT from LBW vs normal birthweight (NBW) men (false discovery rate < 5%), including sites in the FADS2 and CPLX1 genes previously associated with type 2 diabetes. When we used reference-free cell mixture adjustments to potentially adjust for cell composition, 4,323 sites had differential methylation in LBW vs NBW men. However, no differences in SAT gene expression levels were identified between LBW and NBW men. In the combined group of all 40 participants, 3,276 genes (16.5%) were differentially expressed in SAT after HFO (false discovery rate < 5%) and there was no difference between LBW men and controls. The most strongly upregulated genes were ELOVL6, FADS2 and NNAT; in contrast, INSR, IRS2 and the SLC27A2 fatty acid transporter showed decreased expression after HFO. Interestingly, SLC27A2 expression correlated negatively with diabetes- and obesity-related traits in a replication cohort of 142 individuals. DNA methylation at 652 CpG sites (including in CDK5, IGFBP5 and SLC2A4) was altered in SAT after overfeeding in this and in another cohort. Conclusions/interpretation Young men who had a LBW exhibit epigenetic alterations in their adipose tissue that potentially influence insulin resistance and risk of type 2 diabetes. Short-term overfeeding influences gene transcription and, to some extent, DNA methylation in adipose tissue; there was no major difference in this response between LBW and control participants.
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| 2. |
- Nilsson, Emma A, et al.
(författare)
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Altered DNA Methylation and Differential Expression of Genes Influencing Metabolism and Inflammation in Adipose Tissue From Subjects With Type 2 Diabetes
- 2014
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Ingår i: Diabetes. - : American Diabetes Association. - 0012-1797 .- 1939-327X. ; 63:9, s. 2962-2976
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Tidskriftsartikel (refereegranskat)abstract
- Genetics, epigenetics, and environment may together affect the susceptibility for type 2 diabetes (T2D). Our aim was to dissect molecular mechanisms underlying T2D using genome-wide expression and DNA methylation data in adipose tissue from monozygotic twin pairs discordant for T2D and independent case-control cohorts. In adipose tissue from diabetic twins, we found decreased expression of genes involved in oxidative phosphorylation; carbohydrate, amino acid, and lipid metabolism; and increased expression of genes involved in inflammation and glycan degradation. The most differentially expressed genes included ELOVL6, GYS2, FADS1, SPP1 (OPN), CCL18, and IL1RN. We replicated these results in adipose tissue from an independent case-control cohort. Several candidate genes for obesity and T2D (e.g., IRS1 and VEGFA) were differentially expressed in discordant twins. We found a heritable contribution to the genome-wide DNA methylation variability in twins. Differences in methylation between monozygotic twin pairs discordant for T2D were subsequently modest. However, 15,627 sites, representing 7,046 genes including PPARG, KCNQ1, TCF7L2, and IRS1, showed differential DNA methylation in adipose tissue from unrelated subjects with T2D compared with control subjects. A total of 1,410 of these sites also showed differential DNA methylation in the twins discordant for T2D. For the differentially methylated sites, the heritability estimate was 0.28. We also identified copy number variants (CNVs) in monozygotic twin pairs discordant for T2D. Taken together, subjects with T2D exhibit multiple transcriptional and epigenetic changes in adipose tissue relevant to the development of the disease.
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| 4. |
- Rönn, Tina, et al.
(författare)
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Age influences DNA methylation and gene expression of COX7A1 in human skeletal muscle.
- 2008
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Ingår i: Diabetologia. - : Springer Science and Business Media LLC. - 1432-0428 .- 0012-186X. ; 51:7, s. 1159-1168
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Tidskriftsartikel (refereegranskat)abstract
- AIMS/HYPOTHESIS: Reduced oxidative capacity of the mitochondria in skeletal muscle has been suggested to contribute to insulin resistance and type 2 diabetes. Moreover, a set of genes influencing oxidative phosphorylation (OXPHOS) is downregulated in diabetic muscle. Here we studied whether genetic, epigenetic and non-genetic factors influence a component of the respiratory chain, COX7A1, previously shown to be downregulated in skeletal muscle from patients with type 2 diabetes. The specific aims were to: (1) evaluate the impact of genetic (single nucleotide polymorphisms [SNPs]), epigenetic (DNA methylation) and non-genetic (age) factors on the expression of COX7A1 in human skeletal muscle; and (2) investigate whether common variants in the COX7A1 gene are associated with increased risk of type 2 diabetes. METHODS: COX7A1 mRNA expression was analysed in muscle biopsies from young (n = 110) and elderly (n = 86) non-diabetic twins and related to measures of in vivo metabolism. Genetic variants (three SNPs) from the COX7A1 locus were genotyped in the twins and in two independent type 2 diabetes case-control cohorts (n = 1466 and 6380, respectively). DNA methylation of the COX7A1 promoter was analysed in a subset of twins (ten young, ten elderly) using bisulphite sequencing. RESULTS: While DNA methylation of the COX7A1 promoter was increased in muscle from elderly compared with young twins (19.9 +/- 8.3% vs 1.8 +/- 2.7%; p = 0.035), the opposite was found for COX7A1 mRNA expression (elderly 1.00 +/- 0.05 vs young 1.68 +/- 0.06; p = 0.0005). The heritability of COX7A1 expression was estimated to be 50% in young and 72% in elderly twins. One of the polymorphisms investigated, rs753420, influenced basal COX7A1 expression in muscle of young (p = 0.0001) but not of elderly twins. The transcript level of COX7A1 was associated with increased in vivo glucose uptake and [Formula: see text] (p = 0.009 and p = 0.001, respectively). We did not observe any genetic association between COX7A1 polymorphisms and type 2 diabetes after correcting for multiple testing. CONCLUSIONS/INTERPRETATION: Our results provide further evidence for age as a factor influencing DNA methylation and expression of OXPHOS genes, and thereby in vivo metabolism.
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| 6. |
- 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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