骨髓间充质干细胞参与牙髓损伤修复的体内实验研究

目的:观察体内的骨髓间充质干细胞(BMMSCs)能否参与牙髓损伤的局部修复,初步探讨骨髓间充质干细胞在牙髓损伤修复中的作用。方法:构建绿色荧光蛋白转基因大鼠骨髓间充质干细胞(GFP-BMMSCs)嵌合SD大鼠模型,30 d后,通过流式细胞术检测外周血单核细胞和骨髓间充质干细胞中荧光细胞的比例,冰冻切片观察心、肝、肾组织中是否有荧光细胞的分布,检测模型是否构建成功。然后利用该模型,通过制备牙本质缺损构建牙髓损伤模型,分别于牙本质缺损后5、10、15 d取材,切片,HE及免疫荧光染色,观察牙髓的病理变化以及GFP-BMMSCs在牙髓组织中的分布情况和变化。结果:HE染色可见牙本质缺损组初期有牙髓充血,后期牙髓炎症逐渐恢复并有修复性牙本质形成。免疫荧光染色可见牙髓组织中有荧光细胞的分布,牙本质缺损组比正常组中可见更多的荧光细胞,且随着牙髓炎症的恢复,荧光细胞减少。结论:牙髓损伤时,骨髓间充质干细胞可以迁移到损伤的牙髓处参与其损伤的修复。

Roles of bone marrow mesenchymal stem cells on the repair of injured pulp:an in vivo study

AIM: To investigate if bone marrow mesenchymal stem cells(BMMSCs) take part in the repair of pulp injury and explore the role of BMMSCs in this process.METHODS: A SD rat model jointed with GFP-BMMSCs was established.The ratios of GFP+ cells in peripheral blood monouclear cells and BMMSCs were determined by flow cytometry,and the expressions of GFP+ cells in the heart,liver and kidney were detected by frozen section so as to confirm the successful establishment of the model at day 30 after cell transplantation.Pulp injury rat model was established by making dentin defects 5 d,10 d,15 d after dentin defects.HE and immunofluorescence staining were used to observe the regeneration of dental pulp and the distribution of GFP+cells.RESULTS: Pulp hyperaemia was observed at the beginning of dentin defects and reparative dentin was detected by HE staining.More GFP+ cells were seen in the area of dentin defect than in the control by immunofluorescence staining,and GFP+ cells reduced with the recovery of pulp inflammation.CONCLUSION: Bone marrow mesenchymal stem cells are involved in the repair of pulp injurys.