Human adipose stem cells can differentiate into various mesodermic lineages, including adipogenic, osteogenic, chondrogenic, myogenic and endothelial pathways. In addition, these cells types possess immunomodulatory properties, potentially useful for autoimmune and autoinflammatory diseases. However, single-cell expanded clones have shown that the cells can present a variety of differentiation potential, which may be partly due to epigenetic differences among them. The objective of this study was to assess if DNA methylation plays a role in the differentiation potential observed between different cell clones obtained from the same donor. To this end, the methylation profile of five clonal cell lines of human adipose stem cells obtained by liposuction from two donors was analyzed. Previous reports demonstrated that cell lines 1.7 and 1.22 from Donor 1 and 3.5 from Donor 3 were adipogenic-osteogenic, but not cell lines 1.10 and 3.10. The genes analyzed were neuronal, endothelial, myogenic, osteogenic, adipogenic, extracellular matrix, cell cycle, cytoskeleton and metabolic enzymes. All clones analyzed in this study displayed a similar pattern of methylation in most of the gene families: 85.5% were hypomethylated genes and 14.5% hypermethylated. In conclusion, the methylation pattern of the 1113 genes studied in this report was not a consistent tool to identify the differentiation potential of human adipose stem cells.
Keywords: Adipose cells; DNA methylation; adult stem cells; cell differentiation; mesoderm lineages.