Studies Of MMP-3and CCN2in The Process Of Dental Pulp Injury And Repair

Objective：During dental pulp injury and repair process observe the changes ofthe rate of cell migration in the cultivate human dental pulp cells in vitrowhich are induced MMP-3and CCN2and the effect of MMP-3on the mRNAof CCN2expression, which are to investigate MMP-3promoting dental pulprepair functions and reveal its mechanism.Method: The human pulp fibroblasts were obtained from the healthy thirdmolars which were extracted for orthodontic and impacted reason by the tissueblack enzymolytic method. Firstly, we conduced the experiments in two partsby Transwell method. Respectively, MMP-3（100ng/ml） and CCN2（100ng/ml）were induced in human dental pulp fibroblasts. We observe the effects ofchanges in the activity of cell migration at different time (12h，24h and48h).Then the experiment was divided into six groups which were MMP-3group（100ng/ml）, antiCCN2group（1ug/ml）, MMP3+antiCCN2(0.01ug/ml) group, MMP3+antiCCN2(0.1ug/ml) group, MMP3+antiCCN2(1ug/ml) groupand control group. Changes in the activity of cell migration were observed after24hours. At last changes of CCN2mRNA expressed in human dental pulpfibroblasts stimulated by MMP-3were detected by means of RT-PCR at different times((30min,1h,3h,6h,9h,12h).Results: Cell migration experiment was divided into two parts. In the first part，MMP-3and CCN2markedly induced the migration of dental pulp cells（P<0.001）. MMP-3and CCN2also time-dependently influenced the migration(P<0.001). In the second part, there were no significant differences between thecontrol group and antiCCN2group(P>0.05); That MMP-3group respectivelycompared with MMP3+antiCCN2（0.01ug/ml）group、MMP3+antiCCN2（0.1ug/ml）and MMP3+antiCCN2（1ug/ml）had a statistically significant difference(P<0.001). In RT-PCR method, changes of CCN2mRNA expressed in humandental pulp fibroblasts that were stimulated by MMP-3showed the time-dependent change. And it reached the maximum at30minutes.Conclusions: MMP-3failed to induce the dental pulp cell migration in thepresence of antiCCN2antibody, suggesting that MMP-3accelerates the cellmigration via CCN2. CCN2also participates vital processes for healing ofinjured dental pulp by migration. In addition, MMP-3clearly induced theexpression of CCN2mRNA. Therefore it is conceivable that MMP-3takes acritical part in dental pulp wound healing through up-regulation of CCN2.When MMP-3promotes the pulp injury and repair, we can never ignore theimportance of CCN2. They not only provided the great theoretical basis forthe research development of new pulp capping materials in clinical work, butalso gave a new method of biological treatment for pulp injury.