The Study Of Growth And Differentiation Factors To Dental Pulp Stem Cells And Dental Papilla Cells

Dental pulp stem cells are one of the important seed cells for tooth tissue engineering, with the high proliferation ability, self-renewal and multilineage differentiation capacity, which have played an important role in maintenance of dynamic equilibrium of dental pulps. As a result of tooth development is a long-term and complex process, this period is influenced by many factors, the body's own state, the local micro-environment of the teeth, as well as the interaction between cells, signaling molecules inside and outside of cells, these factors are involved in regulating the development of teeth. By comparing the differences between dental pulp stem cells from juvenile and adult rats to better understand the basic characteristics of dental pulp stem cells, observe the impact of micro-environment from different periods of dental pulp cells on the biological characteristics of dental pulp stem cells, and silence the maxillofacial development related gene Mcpr1 in dental papilla cells, the dental pulp stem cell precursor cells, in order to observe the impact of Mcpr1 on the proliferation ability of the dental papilla cells.1 The differences between dental pulp stem cells from juvenile and adult ratsWe used 2-week-old and 4-month-old SD rats as research model, first, observed the differences between the two periods of dental pulps in situ, and then cultured dental pulp stem cells in vitro, detected the differences of proliferation capacity of dental pulp stem cells with MTT, and cell cycle, detected the expression of osteogenic gene with real-time PCR, detected ALP activity with alkaline phosphate detection kit, compared the differences of mineralization ability of dental pulp stem cells after osteogenic induction, and transplanted the cell pellets of dental pulp stem cells from juvenile and adult rats in renal capsules to compare the mineralization capacity in vivo. The results showed that: juvenile dental pulp stem cells exhibited higher proliferation ability than adult dental pulp stem cells, and adult dental pulp stem cells exhibited higher mineralization ability than juvenile dental pulp stem cells.2 Effect of dental pulp cell-conditioned medium on proliferation and differentiation capacity of dental pulp stem cellsIn order to verify the effect of cell micro-environment on the dental pulp stem cells, we utilized dental pulp cells from juvenile and adult rats, and collected the cell culture medium, respectively. We used these two cell-conditioned medium of dental pulp cells to induce these two period dental pulp stem cells, testing the changes of proliferation and differentiation capacity. The results show that: the proliferation ability of adult dental pulp stem cells which were induced by juvenile dental pulp cell-conditioned medium increased. And the proliferation ability of juvenile dental pulp stem cells which were induced by adult dental pulp cell-conditioned medium weakened. In differentiation also show the same trend, the differentiation ability of adult dental pulp stem cells which were induced by juvenile dental pulp cell-conditioned medium weakened. And the differentiation ability of juvenile dental pulp stem cells which were induced by adult dental pulp cell-conditioned medium increased. These results suggest that cell-conditioned medium can be used as a micro-environment to change the differences due to the age.3 The effect of Mcpr1 on the proliferation of dental papillia cellsIn order to verify the maxillofacial development related gene Mcpr1 also play a role in tooth development, we used RNAi technology to silence Mcpr1 in the dental papilla cells. The results showed that gene silencing of Mcpr1 promotes the cell proliferation ability in rat dental papilla cells. This indicates that Mcpr1 could inhibit the proliferation of dental papilla cells. These results suggest that Mcpr1 not only involve in the occurrence of cleft palate by inhibiting the proliferation of palatal mesenchymal cells but also involve in tooth diseases by inhibiting the proliferation of dental papilla cells.