Differentiation of Rat Dental Pulp-derived Cells into an Osteoblastic Lineage
Differentiation of Rat Dental Pulp-derived Cells into an Osteoblastic Lineage
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DOI：
10.1016/s1348-8643(05)80014-x
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发表时间：
2005-11-01
影响因子：
0.5
通讯作者：
Ohura, Kiyoshi
中科院分区：
文献类型：
--
作者：
Nozaki, Tadashige;Takeyasu, Masaharu;Ohura, Kiyoshi
大鼠牙髓来源的细胞在体外分化为成骨细胞系的潜力进行了检查。在用于来自人骨髓的间充质干细胞的体外成骨诱导条件下进行诱导。我们以前报道过，诱导后6周的矿化水平很高，通过von Kossa染色确定。在本研究中，我们定量测定诱导后的碱性磷酸酶（ALP）活性。在诱导后1、2、3和6周，ALP阳性细胞占总细胞的比率分别为44.4 +/- 1.0、46.9 +/- 0.9、40.5 +/- 0.5和21.0 +/- 1.8%。诱导后6周，ALP活性水平明显下降（p < 0.05）。干细胞标志物STRO-1、SSEA-1、Nanog和Oct-3/4在细胞亚群中表达，表明存在干细胞。为了阐明成骨细胞系中的基因调控，使用实时RT-PCR进行定量基因表达分析。诱导后6周，Col 1a 2（I型胶原）和Bglap（骨钙素）分别上调约1.7倍和1.3倍，与1周时的相应水平相比。这些结果表明，在诱导过程中，细胞分化成骨细胞谱系与ALP活性降低平行。诱导后Col 1a 2和Bglap的表达与Alpl（ALP）的表达呈负相关，而Alpl的表达与Bmp 2的表达呈正相关。总之，研究结果表明，这些分子有助于大鼠牙髓来源的细胞分化成成骨细胞谱系。
The in vitro differentiation potential of rat dental pulp-derived cells into an osteoblastic lineage was examined. Induction was carried out under in vitro osteogenesis-inducing conditions used for mesenchymal stem cells from human bone marrow. We previously reported that the level of mineralization was high at 6 weeks after induction, as determined by von Kossa staining. In the present study, we quantitatively measured the alkaline phosphatase (ALP) activity after induction. The ratios of ALP-positive cells to total cells were 44.4 +/- 1.0, 46.9 +/- 0.9, 40.5 +/- 0.5 and 21.0 +/- 1.8% at 1, 2, 3 and 6 weeks after induction, respectively. The level of ALP activity was significantly decreased at 6 weeks after induction (p < 0.05). The stem cell markers STRO-1, SSEA-1, Nanog and Oct-3/4 were expressed in a subset of the cells, suggesting that stem cells were present. To elucidate gene regulation in the osteoblastic lineage of the cells, quantitative gene expression analyses were carried out using real-time RT-PCR. Col1a2 (collagen type I) and Bglap (osteocalcin) were up-regulated by about 1.7-fold and 1.3-fold, respectively, at 6 weeks after induction compared with their corresponding levels at 1 week. These results indicate that the cells differentiated into an osteoblastic lineage in parallel with decreasing ALP activity during induction. Moreover, the expressions of Col1a2 and Bglap were inversely correlated with Alpl (ALP) expression after induction, which was correlated with Bmp2 (bone morphogenetic protein 2) expression. Taken together, the findings indicate that these molecules contribute to the differentiation of rat dental pulp-derived cells into an osteoblastic lineage.