GSE173765
Next Generation Sequencing Facilitates Quantitative Analysis of Brown Adipose Tissues from 3bKO and fl/fl Control Mice after 20-week High-Fat Diet Feeding
A persistent influx of energy due to intake over expenditure leads to obesity. Increasing energy expenditure through activation of brown fat thermogenesis is a promising therapeutic strategy for the treatment of obesity. Epigenetic regulation has emerged as a key player in regulating brown fat development and thermogenic program. Here we aimed to study the role of DNA methyltransferase 3b (Dnmt3b), a DNA methyltransferase involved in de novo DNA methylation, in the regulation of brown fat function and energy homeostasis during diet-induced obesity (DIO). We have generated a genetic model with Dnmt3b deletion in brown fat-skeletal lineage precursor cells (3bKO mice) by crossing Dnmt3b-floxed (fl/fl) mice with Myf5-Cre mice. Female 3bKO mice were prone to diet-induced obesity and were insulin resistant. This was associated with decreased energy expenditure, which may largely account for the obese phenotype as there was no difference in food intake and locomotor activity between 3bKO and fl/fl mice. Dnmt3b deficiency impaired mitochondrial and thermogenic program in brown fat. Surprisingly, further RNA-seq analysis revealed a profound up-regulation of myogenic markers in the brown fat of 3bKO mice, suggesting a myocyte-like remodeling in brown fat, which may explain the impaired thermogenic program in brown fat. Further motif enrichment and pyrosequencing analysis suggested myocyte enhancer factor 2C (Mef2c) as a mediator for the myogenic alteration in Dnmt3b-deficient brown fat as indicated by decreased methylation at its promoter. Our data demonstrate that brown fat Dnmt3b is a key regulator of brown fat development, energy metabolism and obesity in female mice. Overall design: Brwon adiipocytes mRNA profiles of fl/fl and 3bKO mice after 20-Week High-fat diet feeding