Epigenetic changes of mesenchymal stem cells in three-dimensional (3D) spheroids

Mesenchymal stem cells (MSCs) hold profound promise in tissue repair/regeneration. However, MSCs undergo remarkable spontaneous differentiation and aging during monolayer culture expansion. In this study, we found that 2-3 days of three-dimensional (3D) spheroid culture of human MSCs (hMSCs) that had been expanded in monolayer for six passages increased their clonogenicity and differentiation potency to neuronal cells. Moreover, in accordance with these changes, the expression levels of miRNA which were involved in stem cell potency were changed and levels of histone H3 acetylation in K9 in promoter regions of Oct4, Sox2 and Nanog were elevated. Our results indicate that spheroid culture increases their multi-potency and changes the epigenetic status of pluripotent genes in hMSCs.