Yang Xuechao, van der Kraan Peter M, van den Dolder Juliette, Walboomers X Frank, Bian Zhuan, Fan Mingwen, Jansen John A
Department of Periodontology and Biomaterials, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands.
Tissue Eng. 2007 Nov;13(11):2803-12. doi: 10.1089/ten.2006.0439.
Dental pulp stem cells harbor great potential for tissue-engineering purposes. However, previous studies have shown variable results, and some have reported only limited osteogenic and odontogenic potential.Because bone morphogenetic proteins (BMPs) are well-established agents to induce bone and dentin formation,in this study STRO-1-selected rat dental pulp-derived stem cells were transfected with the adenoviral mediated human BMP-2 gene. Subsequently, the cells were evaluated for their odontogenic differentiation ability in medium not containing dexamethasone or other stimuli. Cultures were investigated using light microscopy and scanning electron microscopy (SEM) and evaluated for cell proliferation, alkaline phosphatase(ALP) activity, and calcium content. Real-time polymerase chain reaction (PCR) was performed for gene expression of Alp, osteocalcin, collagen type I, bone sialoprotein, dentin sialophosphoprotein, and dentin matrix acidic phosphoprotein 1. Finally, an oligo-microarray was used to profile the expression of odontogenesis-related genes. Results of ALP activity, calcium content, and real-time PCR showed that only BMP2-transfected cells had the ability to differentiate into the odontoblast phenotype and to produce a calcified extracellular matrix. SEM and oligo-microarray confirmed these results. In contrast, the non-transfected cells represented a less differentiated cell phenotype. Based on our results, we concluded that the adenovirus can transfect STRO-1 selected cells with high efficacy. After BMP2 gene transfection, these cells had the ability to differentiate into odontoblast phenotype, even without the addition of odontogenic supplements to the medium.
牙髓干细胞在组织工程领域具有巨大潜力。然而，先前的研究结果参差不齐，一些研究报告称其成骨和成牙潜力有限。由于骨形态发生蛋白（BMPs）是诱导骨和牙本质形成的成熟因子，在本研究中，用腺病毒介导的人BMP-2基因转染STRO-1分选的大鼠牙髓来源干细胞。随后，在不含有地塞米松或其他刺激物的培养基中评估这些细胞的成牙分化能力。使用光学显微镜和扫描电子显微镜（SEM）对培养物进行研究，并评估细胞增殖、碱性磷酸酶（ALP）活性和钙含量。对Alp、骨钙素、I型胶原、骨唾液蛋白、牙本质涎磷蛋白和牙本质基质酸性磷酸蛋白1进行实时聚合酶链反应（PCR）以检测基因表达。最后，使用寡核苷酸微阵列分析成牙相关基因的表达。ALP活性、钙含量和实时PCR结果表明，只有转染BMP2的细胞具有分化为成牙本质细胞表型并产生钙化细胞外基质的能力。SEM和寡核苷酸微阵列证实了这些结果。相比之下，未转染的细胞表现出分化程度较低的细胞表型。基于我们的结果，我们得出结论，腺病毒可以高效转染STRO-1分选的细胞。BMP2基因转染后，即使在培养基中不添加成牙补充剂，这些细胞也具有分化为成牙本质细胞表型的能力。
