中文摘要：

目的：研究大鼠骨髓间充质干细胞（BMMSCs）与牙髓细胞（DPCs）体外共培养后细胞增殖、分化的生物学特征,探讨采用BMMSCs与DPCs共培养获得牙髓再生组织工程学种子细胞的可行性。方法：分别在体外分离培养大鼠BMMSCs和DPCs,并分别传至第3代。通过成骨及成脂诱导进行BMMSCs鉴定。取第3代DPCs和BMMSCs分为3组,（1）DPCs组;（2）共培养组;（3）BMMSCs组。共培养时间为6d,取出细胞半定量聚合酶联反应检测基质细胞抗原-1（Stro-1）及牙本质涎磷蛋白（DSPP）的基因表达量,并用四甲基偶氮唑蓝（MTT）法绘制细胞生长曲线。结果：1DPCs传至第3代后,细胞形态稳定均一,呈成纤维细胞样,长梭形;BMMSCs传至第3代后,细胞形态稳定均一,呈长梭形,平行排列或呈漩涡状生长,成脂成骨染色阳性。2细胞生长曲线示：共培养组的DPCs较DPCs组先进入指数生长期。共培养组BMMSCs较BMMSCs组后进入指数生长期。3Stro-1的表达量：BMMSCs组表达量最高,共培养组BMMSCs表达量下降;DPCs组表达量最低,共培养组DPCs表达量上升,差异有统计学意义（P=0.000）。DSPP的表达量：共培养组DPCs较DPCs组表达量下降;共培养组BMMSCs较BMMSCs组表达量上升,差异有统计学意义（P=0.019）。结论：BMMSCs与DPCs共培养,可以促进DPCs的增殖,以及有去分化的趋势;抑制BMMSCs的增殖,具有向DPCs分化的趋势。

英文摘要：

Objective This research investigated the proliferation and differentiation of cells in bone marrow mesenchymal stem cells （BMMSCs） and dental pulp cells（DPCs） co-culture system, and to explore the feasibility of the dental pulp regeneration with co culture BMMSCs and DPCs as seed cells. Methods.. Isolated and cultured the BMMSCs and DPCs from rat. Cells from passages 3 of each cell types were used in all experiments. The characteristics and multilineage differentiation capacity of the BMMSCs was confirmed by using osteo-odontogenic and adipogenic induction media. All cell types were divided into three groups： （1） DPCs group, （2） co culture group, and （3） BMMSCs group. After 6-day co culture, cells were extracted and detected their mRNA expression of STRO-1 and DSPP by polymerse chain reaction. In addition, the growth curves of experiment groups were obtained with the MTT assay. Results： （1） The passage 3 DPCs showed cells morphology was stabile which was fibroblast-like with splindle shape l and the passage 3 BMMSCs showed stable cell morphology with splindle shape which was parallel-aligned or vortex arrangement. The BMMSCs after osteo-odontogenic and adipogenic inducing, revealed mineralization nodules and lipid drops significantly. （2） The growth curve： the DPCs in co culture group entered logarithmic growth phase earlier compared to the DPCs group. However, the BMMSCs in co-culture group accessed into the logarithmic growth phase later than the BMMSCs group. （3） The mRNA expression of Stro-l： the Stro 1 mRNA expression of BMMSCs group was the highest, but it was significantly decreased in co-culture group BMMSCs. However, the Stro-1 mRNA expression of DPCs was obviously lower than the DPCs in co-culture group. The mRNA expression of DSPP： The DSPP mRNA expression of DPCs in co culture group decreased compared to the DPCs group. At the same time, The DSPP mRNA expression of BMMSCs in co-culture group increased significantly, compared to the BMMSCs group. Conclusion：