Bone is a major organ in the skeletal system that supports and protects muscles and other organs, facilitates movement and hematopoiesis, and forms a reservoir of minerals including calcium. The cells in the bone, such as osteoblasts, osteoclasts, and osteocytes, orchestrate sequential and balanced regulatory mechanisms to maintain bone and are capable of differentiating in bones. Bone development and remodeling require a precise regulation of gene expressions in bone cells, a process governed by epigenetic mechanisms such as histone modification, DNA methylation, and chromatin structure. Importantly, lineage-specific transcription factors can determine the epigenetic regulation of bone cells. Emerging data suggest that perturbation of epigenetic programs can affect the function and activity of bone cells and contributes to pathogenesis of bone diseases, including osteoporosis. Thus, understanding epigenetic regulations in bone cells would be important for early diagnosis and future therapeutic approaches.
