Background: Adipose-derived stem cells and ceiling culture-derived preadipocytes can be harvested from subcutaneous adipose tissue. Little is known about the epigenetic differences, which may contribute to differences in osteogenic potential, between these cell types. The purpose of this study was to address the osteogenic potential and underlying epigenetic status of adipose-derived stem cells and ceiling culture-derived preadipocytes.
Methods: Adipose-derived stem cells and ceiling culture-derived preadipocytes were cultured from abdominal subcutaneous fat tissues of four metabolically healthy, lean female patients. After 7 weeks of culture, cellular responses to osteogenic differentiation media were examined. To evaluate the osteogenic potentials of undifferentiated adipose-derived stem cells and ceiling culture-derived preadipocytes, two types of epigenetic assessment were performed using next-generation sequencing: DNA methylation assays with the Human Methylation 450K BeadChip, and chromatin immunoprecipitation assays for trimethylation of histone H3 at lysine 4.
Results: Human ceiling culture-derived preadipocytes showed greater osteogenic differentiation ability than did adipose-derived stem cells. In an epigenetic survey of the promoters of four osteogenic regulator genes (RUNX2, SP7, ATF4, and BGLAP), the authors found a general trend toward decreased CpG methylation and increased trimethylation of histone H3 at lysine 4 levels in ceiling culture-derived preadipocytes as compared to adipose-derived stem cells, indicating that these genes were more likely to be highly expressed in ceiling culture-derived preadipocytes.
Conclusions: The surveyed epigenetic differences between adipose-derived stem cells and ceiling culture-derived preadipocytes were consistent with the observed differences in osteogenic potential. These results enhance the authors' understanding of these cells and will facilitate their further application in regenerative medicine.