人类年轻恒牙牙髓干细胞体外多向分化的能力

Multilineage potential of pulp stem cells from human young permanent teeth in vitro

目的:从人类的年轻恒牙中分离、培养牙髓间充质细胞,并探讨其基本的干细胞生物学特性及体外的多向分化能力。方法:对人类的正畸减数年轻恒前磨牙中分离培养的牙髓细胞进行相差显微镜和透射电镜观察,利用流式细胞仪分析牙髓间充质细胞表型特征和细胞周期时相,并在体外进行定向诱导。结果:从年轻恒牙牙髓中分离培养得到的牙髓间充质细胞为成纤维样;细胞器发育较好;有间充质干细胞的表面特征:CD90,CD44和CD147阳性细胞的比例很高,CD34,CD38,CD45和HLA-DR的阳性比例很低;有很强的增殖生长能力;经体外诱导年轻牙髓细胞可在体外向成骨细胞、脂肪细胞和神经细胞分化,但不能被诱导成为软骨细胞。结论:从人类年轻恒牙牙髓中可以分离培养得到的牙髓间充质干细胞,具有较高的增殖能力和间充质干细胞表面特征,在体外诱导下能分化为成骨细胞、脂肪细胞和神经元,具有多向分化的潜能。

Objective ：To isolate and culture the pulp cells from human young permanent teeth （pDPC）, and to observe their biological characteristics and the expression of some specific markers, and to induce these pulp cells to differentiate into osteoblast, adipocyte, neuron and chondrocyte lineages. Methods：Pulp cells were isolated and cultured from orthodontic extracted premolars of children. The attached cells after at least 3 passages were used for the following experiments ： 1. Morphology and uhrastructure analysis; 2. Cell cycle and phenotype were analyzed by flowcytometry; 3. Growth curve were recorded;4. pDPC were induced to differentiate into osteoblast, adipocyte, neuron in vitro, and were identified by histochemical methods and RT-PCR. Results： 1. Attached pDPCs were fibrablast-like cells,which were distinguished from BMSC. 2. The cell organs in dDPCs were well developed. 3. pDPCs were highly positive for CDg0, CD44, CD147,which are mesenchymal stem-cell markers, but were negative for other markers including CD34, CD38, CD45, HLA-DR. 4. pDPCs showed high growth rate. 5. pDPCs could be induced to differentiate into osteoblast, adipocyte, and neuron lineages, but not chondrocyte lineages. Conclusion：pDPCs were characterized by their ability to proliferate with high growth rate in vitro. The expression of some BMSC markers in these cells were observed. They showed the potential to differentiate into multiple mesenchymal lineages such as osteoblst, adipocyte, neuron lineages under specific conditions in vitro.