DNA methylation and demethylation are two important mechanisms of epigenetics, which is important in the study of cell differentiation, proliferation, and senescence. During osteogenic differentiation of stem cells, the expression of osteogenic specific genes and demethylated promoters is upregulated, whereas the expression of pluripotent genes and hyper- methylated promoters is downregulated. The dynamic changes and balance between DNA methylation and demethylation are important for the coordination of gene expression and the inhibition of improper phenotypes. Abnormal changes in the methylation modification mechanism in osteogenic differentiation not only affect the normal function of stem cells but are also associated with the occurrence and development of many common skeletal diseases. This paper reviews the new progress of DNA methylation and demethylation in regulating osteogenic differentiation. The possible skeletal diseases caused by ab- normal DNA methylation are also presented.
