Involvement of mitochondrial biogenesis during the differentiation of human periosteum-derived mesenchymal stem cells into adipocytes, chondrocytes and osteocytes.

Due to a rapidly expanding aging population, the incidence of age-related or degenerative diseases has increased, and efforts to handle the issue with regenerative medicine via adult stem cells have become more important. And it is now clear that the mitochondrial energy metabolism is important for stem cell differentiation. When stem cells commit to differentiate, glycolytic metabolism is being shifted to mitochondrial oxidative phosphorylation (OXPHOS) to meet an increased cellular energy demand required for differentiated cells. However, the nature of cellular metabolisms during the differentiation process of periosteum-derived mesenchymal stem cells (POMSC) is still unclear. In the present study, we investigated mitochondrial biogenesis during the adipogenic, chondrogenic, and osteogenic differentiation of POMSCs. Both mitochondrial DNA (mtDNA) contents and mitochondrial proteins (VDAC and mitochondrial OXPHOS complex subunits) were increased during all of these mesenchymal lineage differentiations of POMSCs. Interestingly, glycolytic metabolism is reduced as POMSCs undergo osteogenic differentiation. Furthermore, reducing mtDNA contents by ethidium bromide treatments prevents osteogenic differentiation of POMSCs. In conclusion, these results indicate that mitochondrial biogenesis and OXPHOS metabolism play important roles in the differentiation of POMCS and suggest that pharmaceutical modulation of mitochondrial biogenesis and/or function can be a novel regulation for POMSC differentiation and regenerative medicine.