DNA methylation levels of CEBPβ gene differentially affected by saturated and polyunsaturated fatty acids in adipogenesis of 3T3‐L1 cells

Abstract

In obesity and type 2 diabetes, adipose and muscle tissues are significantly affected. It has been demonstrated that many of the changes are associated with gene expression. Cultured cell models were used to study the involvement of epigenetic modifications in mediating gene expression affected by hyperlipidemia. Cultured L6 muscle cells and differentiating 3T3‐L1 adipocytes were treated with saturated or polyunsaturated fatty acids to mimic hyperlipidemia conditions. After the treatments, methylation sequencing was conducted to identify the changes of the methylation levels of the genomic DNA samples from the cells. And restriction digestion followed PCR were used to validate the methylation sequencing results. In general, methylation levels of most of the genes were increased while methylation levels of some of the genes were decreased and small portion of the genes changed slightly among the genes with altered methylation levels in differentiating 3T3‐L1 cells treated with a saturated or a polyunsaturated fatty acid. We have demonstrated that both saturated type and polyunsaturated type fatty acids enhanced adipogenesis of differentiating 3T3‐L1 cells. While both saturated and polyunsaturated fatty acids decreased methylation levels of PPARγ gene, only polyunsaturated fatty acids increased methylation levels of C/EBPβ gene. These results are consistent with the knowledge that expression of both PPARγ and C/EBPβ gene are increased in adipogenesis and intake of saturated fat is associated with obesity.