Epigenetic Regulation of Osteogenic and Chondrogenic Differentiation of Mesenchymal Stem Cells in Culture

Management of mesenchymal stem cells (MSCs) capabilities to differentiate in to osteogenic and chondrogenic lineages would be of utmost importance for their future use in difficult to treat cases of destroyed bone and cartilage. Thus, an understanding of the epigenetic mechanisms as important modulators of stem cell differentiation might be useful. Epigenetic mechanism refers to a process that regulates heritable and long-lasting alterations in gene expression without changing the DNA sequence. Such stable changes would be mediated by several mechanisms including DNA methylation and histone modifications. The involvement of epigenetic mechanisms during MSC bone and cartilage differentiation has been investigated during the past decade. The purpose of this review is to cover outstanding research works that have attempted to ascertain the underlying epigenetic changes of the nuclear genome during in vitro differentiation of MSCs into bone and cartilage cell lineages. Understanding such genomic alterations may assist scientists to develop and recognize reagents that are able to efficiently promote this cellular differentiation. Before summarizing the progress on epigenetic regulation of MSC bone and cartilage differentiation, a brief description will be given regarding in vitro conditions that favor MSC osteocytic and chondrocytic differentiation and the main mechanisms responsible for epigenetic regulation of differentiation.