Expression of key genes involved in DNA methylation during in vitro differentiation of porcine mesenchymal stem cells (MSCs) into adipocytes

The normal course of DNA methylation depends on the correct functioning of the DNA methylation machinery, which include DNA methyltransferase enzymes (DNMTs) and methyl-CpG-binding domain proteins (MBDs). So far, little is known about the activity of these components during adipogenesis in the pig. The aim of this study was to analyze the expression of ten genes (DNMT1, DNMT3a, DNMT3b, MBD1, MBD2, MBD3, MBD4, MeCP2, UHRF1, and CBX5) during in vitro differentiation into adipocytes of porcine mesenchymal stem cells derived from adipose (AD-MSC) and from bone marrow tissue (BM-MSC). We found that, in undifferentiated cells, the global methylation level was higher in BM-MSC than in AD-MSC, but had similar levels in adipocytes. The transcript level of the DNMT1 gene increased at the beginning of adipogenesis and then decreased, while DNMT3a and DNMT3b transcripts increased during differentiation. All the examined MBD genes show similar expression patterns within the studied system (AD-MSC and BM-MSC). The transcript abundance of UHRF1 and CBX5 decreased in both systems. The changes in the expression patterns of these genes points to the dynamic nature of DNA methylation during porcine adipogenesis.