DNA Methylation Suppresses Leptin Gene in 3T3-L1 Adipocytes

Abstract

Leptin is a key regulator of energy intake and expenditure. This peptide hormone is expressed in mouse white adipose tissue, but hardly expressed in 3T3-L1 adipocytes. Using bisulfite sequencing, we found that CpG islands in the leptin promoter are highly methylated in 3T3-L1cells. 5-azacytidine, an inhibitor of DNA methyltransferase, markedly increased leptin expression as pre-adipocytes matured into adipocytes. Remarkably, leptin expression was stimulated by insulin in adipocytes derived from precursor cells exposed to 5-azacytidine, but suppressed by thiazolidinedione and dexamethasone. In contrast, adipocytes derived from untreated precursor cells were unresponsive to both 5-azacytidine and hormonal stimuli, although lipid accumulation was sufficient to boost leptin expression in the absence of demethylation. Taken together, the results suggest that leptin expression in 3T3-L1 cells requires DNA demethylation prior to adipogenesis, transcriptional activation during adipogenesis, and lipid accumulation after adipogenesis.

Brown adipose tissue (BAT) specific vaspin expression is increased after obesogenic diets and cold exposure and linked to acute changes in DNA-methylation

“…Given the induction of vaspin gene expression especially in iBAT of cold exposed mice, further analyses were carried out to elucidate potential mechanisms regulating vaspin expression. Thus, we focused on DNA methylation, a reversible epigenetic process enabling the adaption to environmental changes, which has already been shown to affect expression of other important adipokines such as leptin and adiponectin [41] , [42] , [43] . Since a decrease in promoter DNA methylation is mostly accompanied by amended binding of transcription factors (TF) and increased mRNA expression, we focused on analyzing promoter DNA methylation of the vaspin gene at binding sites for PPARγ:RXRα and TCF7L2 – both TFs involved in adipogenesis ( Supplementary Figure 1 ).…”

Increased Expression of the Leptin Gene in Adipose Tissue of Patients with Chronic Kidney Disease–The Possible Role of an Abnormal Serum Fatty Acid Profile

“…Adipose tissue is a highly heterogeneous organ with cell-and depot-specific functions [35][36][37]. However, we chose 3T3-L1 differentiated adipocytes because they are a well-characterized and widely used cell line in metabolic, molecular, and endocrine studies, including studies on leptin expression levels [38][39][40][41].…”

Gender Differences in Adipocyte Metabolism and Liver Cancer Progression

“…Recent studies have also take advantage of cell lines and human mesenchymal stem cells in the study of DNA methylation in the transcriptional activation of leptin and adiponectin genes ( Kuroda et al, 2016 ; Zhang W. et al, 2016 ). On top of this, Ambati et al (2016) have also demonstrated the differential expressions of genes encoding for epigenetic regulators in VAT and SCAT in mice.…”