人牙髓细胞向成牙本质细胞诱导分化中细胞周期变化

目的建立成牙本质细胞样细胞体外培养体系，观察体外培养的牙髓细胞向成牙本质细胞分化过程中细胞周期的变化。方法利用组织块酶解法培养人牙髓细胞并进行鉴定，使用矿化诱导液诱导其向成牙本质细胞样细胞分化。对细胞增殖情况使用流式细胞仪进行细胞周期测定。结果①获得的牙髓细胞均为波形丝蛋白阳性，角蛋白阴性，证明为中胚层来源的细胞。②诱导分化的牙髓细胞在2周左右进入复层生长期；3周左右开始有细胞结节形成．周围细胞呈放射状排列，部分细胞出现细长突起并呈极性排列：4周左右细胞团中央Von Kossa染色为阳性。③在诱导开始后1周，细胞处于活跃的增殖期，以后细胞增殖变慢．3周后多数细胞处于G0G1期。结论实验成功建立了成牙本质细胞样细胞体外培养体系，所获得的成牙本质细胞样细胞具有成牙本质细胞的部分形态和生物学功能，诱导分化后细胞增殖变慢．是研究成牙本质细胞的较好模型。

Changes of Cell Cycle During Dental Pulp Cell Differentiation

Objective To investigate the differentiation of dental pulp cells into odontoblast-like cells correlates with the changes of cells proliferation. Methods Human dental pulp cells were cultured by tissue enzymatic digestion method and identified by vimentin and keratin antibody. Addition of βGP to the culture medium induced odontoblast features in the cultured pulp cells. Light microscopy and yon Kossa staining were applied to observe the morphology and nodel formation of odontoblasts like cells. Flow cytometry were used to detect the changes of cells proliferation during dental pulp cell differentiation. Results Cultured cells were all vimentin positive and keratin negative. At the second week, cells were stratified, then they polarized and some of them exhibited a typical cellular extension at 3rd week. von Kossa staining became positive at the last week. Flow cytometry demonstrated cells proliferation was suppressed, most cells are at the G0/G1 stage. Conclusion Dental pulp cells successfully differentiated into odontoblast -like cells in vitro.