Effect of epigallocatechin gallate (EGCG) on the differentiation of periosteum-derived progenitor cells to insulin-producing cells

초록

Adult stem cells are multipotent cells into specific lineages. They can replenish damaged tissues by cell division and differentiation into specific cell types. Especially, mesenchymal stem cells (MSCs) are an important tool for cell therapy because of their immunosuppressive properties. MSCs are commonly cultured in two-dimensional (2D) systems, but it was reported that 2D culture systems could reduce differentiation capacity of MSCs. In addition, available surface area for the propagation of cells is limited. Therefore, various three-dimensional (3D) culture technologies have been developed. Aggregation of cells can activate cell–cell interactions, resulting in enhanced therapeutic potential by stimulating stem-cell-associated genes. Many studies about 3D culture using spheres have been reported. In this study, we developed a 3D culture system for the expansion of periosteum-derived progenitor cells (PDPCs) as spheres. PDPCs are one of diverse MSCs and they have high proliferation capacity. The spheroid formation of PDPCs was induced by using a rotation platform. The rotation system could provide sufficient nutrient supply and oxygen partial pressure gradients for the growth of the spheres. PDPCs were seeded at a density of 2×106 cells/mL in 35-mm non-adhesive culture dishes. Total volume was 2 mL and the cells were cultivated at a rotation rate of 60 rpm. The 3D culture system could be applied to shake flasks. The spheres maintained their viability and proliferation ability. PDPCs in 3D culture showed more expression of stem-cell-associated genes than 2D culture. Furthermore, the spheres are confirmed to be differentiated into mesodermal lineages. In conclusion, a simple and economical 3D culture system could be developed for the effective cultivation of PDPCs. This system has many advantages in the stem cell culture such as short handling time, easy production process and possibility of scale-up.