Abstract: Objective　 LIM mineralization protein-1 is non-secret protein in the cell, widely existing in various tissues, which not only affects the mineralization of bone matrix but also is the important regulatory factor in the process of osteoblast differentiation and bone formation. This experiment evaluates the effect of intracellular signal transduction molecules LIM mineralization protein 1on dental pulp stem cells in vitro mineralization by detecting the process of mineralization. It can provide the reference for evaluating the LMP-1 as osteogenesis adjustment factor and affecting bone matrix mineralization research. Methods　 Dental pulp stem cells were cultured in vitro，purified and then subcultured . Bone marrow mesenchymal stem cells were cultured in vitro by density gradient centrifugation method. Two kinds of cells were set up respectively into the experimental group and the control group. In the experimental group, the induction fluid was added to the culture medium, but in the control group it was not added. They were detected in 3, 5, 7 and 14 days respectively. Fluorescence quantitative PCR method was used to detect the culture period expression of osteogenic marker genes LIM mineralization protein-1、BMP-2、DSPP、COL-1、RUNX-2. The results were statistically analyzed by SPSS17.0. Results　The activity of alkaline phosphatase increased and the activity of alkaline phosphatase in the experimental group was significantly higher than that in the control group at 5, 3, 7 and 14 days. The formation of mineralized nodules was seen in the experimental group at 21 days. Fluorescent quantitative PCR was used in both the experimental and control groups, and the expression of the experimental group was significantly higher than that of the control group. Conclusions　LIM mineralization protein -1 is associated with the mineralization of dental pulp stem cells in vitro and bone marrow mesenchymal stem cells. It’s speculated that LIM mineralization protein 1 May as the detection of dental pulp stem cells and bone marrow mesenchymal stem cells is an indicator of mineralization.

Key words: DPSC, bone marrow mesenchymal stem cells , LIM mineralization protein-1, BMP-2.