Format

Send to

Choose Destination
Int J Obes (Lond). 2015 Jun;39(6):910-9. doi: 10.1038/ijo.2015.31. Epub 2015 Mar 18.

The fat cell epigenetic signature in post-obese women is characterized by global hypomethylation and differential DNA methylation of adipogenesis genes.

Author information

1
Department of Medicine, Karolinska Institutet, Stockholm, Sweden.
2
Department of Biosciences and Nutrition, Karolinska Institutet, Stockholm, Sweden.
3
1] Department of Clinical Sciences, Danderyds Hospital, Karolinska Institutet., Stockholm, Sweden [2] Department of Surgery, Ersta Hospital, Karolinska Institutet, Stockholm, Sweden.
4
1] Department of Biosciences and Nutrition, Karolinska Institutet, Stockholm, Sweden [2] European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, UK.
5
Department of Clinical Sciences, Epigenetics and Diabetes, Lund University Diabetes Centre, CRC, Scania University Hospital, Malmo, Sweden.
6
1] Department of Biosciences and Nutrition, Karolinska Institutet, Stockholm, Sweden [2] SciLifeLab, Science for Life Laboratory, Solna, Sweden.

Abstract

BACKGROUND/OBJECTIVES:

Obese subjects have increased number of enlarged fat cells that are reduced in size but not in number in post-obesity. We performed DNA methylation profiling in fat cells with the aim of identifying differentially methylated DNA sites (DMS) linked to adipose hyperplasia (many small fat cells) in post-obesity.

SUBJECTS/METHODS:

Genome-wide DNA methylation was analyzed in abdominal subcutaneous fat cells from 16 women examined 2 years after gastric bypass surgery at a post-obese state (body mass index (BMI) 26±2 kg m(-2), mean±s.d.) and from 14 never-obese women (BMI 25±2 kg m(-2)). Gene expression was analyzed in subcutaneous adipose tissue from nine women in each group. In a secondary analysis, we examined DNA methylation and expression of adipogenesis genes in 15 and 11 obese women, respectively.

RESULTS:

The average degree of DNA methylation of all analyzed CpG sites was lower in fat cells from post-obese as compared with never-obese women (P=0.014). A total of 8504 CpG sites were differentially methylated in fat cells from post-obese versus never-obese women (false discovery rate 1%). DMS were under-represented in CpG islands and surrounding shores. The 8504 DMS mapped to 3717 unique genes; these genes were over-represented in cell differentiation pathways. Notably, 27% of the genes linked to adipogenesis (that is, 35 of 130) displayed DMS (adjusted P=10(-8)) in post-obese versus never-obese women. Next, we explored DNA methylation and expression of genes linked to adipogenesis in more detail in adipose tissue samples. DMS annotated to adipogenesis genes were not accompanied by differential gene expression in post-obese compared with never-obese women. In contrast, adipogenesis genes displayed differential DNA methylation accompanied by altered expression in obese women.

CONCLUSIONS:

Global CpG hypomethylation and over-representation of DMS in adipogenesis genes in fat cells may contribute to adipose hyperplasia in post-obese women.

PMID:
25783037
DOI:
10.1038/ijo.2015.31
[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Nature Publishing Group
Loading ...
Support Center