Zhang Weibo, Walboomers X Frank, Shi Songtao, Fan Mingwen, Jansen John A
Radboud University Nijmegen Medical Centre, Periodontology & Biomaterials, Nijmegen, The Netherlands.
Tissue Eng. 2006 Oct;12(10):2813-23. doi: 10.1089/ten.2006.12.2813.
The current study aimed to prove that human dental pulp stem cells (hDPSCs) isolated from the pulp of third molars can show multilineage differentiation after cryopreservation. First, hDPSC were isolated via enzymatic procedures, and frozen in liquid nitrogen until use. After defrosting, cells were analyzed for proliferative potential and the expression of the stem cell marker STRO-1. Subsequently, cells were cultured in neurogenic, osteogenic/odontogenic, adipogenic, myogenic, and chondrogenic inductive media, and analyzed on basis of morphology, immunohistochemistry, and reverse transcriptase-polymerase chain reaction (RT-PCR) for specific marker genes. All data were replicated, and the results of the primary cells were compared to similar tests with an additional primary dental pulp stem cell strain, obtained from the National Institutes of Health (NIH). Results showed that our cell population could be maintained for at least 25 passages. The existence of stem/ progenitor cells in both cell strains was proven by the STRO-1 staining. Under the influence of the 5 different media, both cell strains were capable to advance into all 5 differentiation pathways. Still differences between both strains were found. In general, our primary culture performed better in myogenic differentiation, while the externally obtained cells were superior in the odontogenic/osteogenic and chondrogenic differentiation pathways. In conclusion, the pulp tissue of the third molar may serve as a suitable source of multipotent stem cells for future tissue engineering strategies and cell-based therapies, even after cryopreservation.
当前研究旨在证明，从第三磨牙牙髓中分离出的人牙髓干细胞（hDPSCs）在冷冻保存后可表现出多向分化能力。首先，通过酶法分离hDPSC，并在液氮中冷冻保存备用。解冻后，分析细胞的增殖潜力以及干细胞标志物STRO-1的表达情况。随后，将细胞培养于神经诱导、成骨/成牙本质诱导、成脂诱导、成肌诱导和软骨诱导培养基中，并基于形态学、免疫组织化学以及针对特定标志物基因的逆转录聚合酶链反应（RT-PCR）进行分析。所有数据均进行了重复实验，并将原代细胞的结果与从美国国立卫生研究院（NIH）获得的另一原代牙髓干细胞株的类似测试结果进行了比较。结果显示，我们的细胞群体至少可传代25次。STRO-1染色证明了两种细胞株中均存在干/祖细胞。在5种不同培养基的影响下，两种细胞株均能够向所有5种分化途径发展。不过，仍发现了两种细胞株之间的差异。总体而言，我们的原代培养物在成肌分化方面表现更佳，而从外部获得的细胞在成牙本质/成骨和软骨分化途径中更具优势。总之，即使经过冷冻保存，第三磨牙的牙髓组织仍可能作为未来组织工程策略和基于细胞的治疗中多能干细胞的合适来源。
