Centro de Pesquisas Gonçalo Moniz, FIOCRUZ, Salvador, Bahia, Brazil.
Arch Oral Biol. 2011 Nov;56(11):1247-55. doi: 10.1016/j.archoralbio.2011.05.008. Epub 2011 Jun 16.
Several studies have demonstrated that human dental pulp is a source of mesenchymal stem cells. To better understand the biological properties of these cells we isolated and characterized stem cells from the dental pulp of EGFP transgenic mice.
The pulp tissue was gently separated from the roots of teeth extracted from C57BL/6 mice, and cultured under appropriate conditions. Flow cytometry, RT-PCR, light microscopy (staining for alkaline phosphatase) and immunofluorescence were used to investigate the expression of stem cell markers. The presence of chromosomal abnormalities was evaluated by G banding.
The mouse dental pulp stem cells (mDPSC) were highly proliferative, plastic-adherent, and exhibited a polymorphic morphology predominantly with stellate or fusiform shapes. The presence of cell clusters was observed in cultures of mDPSC. Some cells were positive for alkaline phosphatase. The karyotype was normal until the 5th passage. The Pou5f1/Oct-4 and ZFP42/Rex-1, but not Nanog transcripts were detected in mDPSC. Flow cytometry and fluorescence analyses revealed the presence of a heterogeneous population positive for embryonic and mesenchymal cell markers. Adipogenic, chondrogenic and osteogenic differentiation was achieved after two weeks of cell culture under chemically defined in vitro conditions. In addition, some elongated cells spontaneously acquired a contraction capacity.
Our results reinforce that the dental pulp is an important source of adult stem cells and encourage studies on therapeutic potential of mDPSC in experimental disease models.
多项研究表明，人类牙髓是间充质干细胞的来源之一。为了更好地了解这些细胞的生物学特性，我们从 EGFP 转基因小鼠的牙髓中分离并鉴定了干细胞。
从 C57BL/6 小鼠提取的牙齿根部轻轻分离牙髓组织，并在适当的条件下进行培养。采用流式细胞术、RT-PCR、荧光显微镜（碱性磷酸酶染色）和免疫荧光法检测干细胞标志物的表达。通过 G 带分析评估染色体异常的存在。
小鼠牙髓干细胞（mDPSC）具有高度增殖性、贴壁性和多形性，形态主要为星状或梭形。在 mDPSC 的培养物中观察到细胞簇的存在。一些细胞呈碱性磷酸酶阳性。核型在第 5 代之前正常。mDPSC 中检测到 Pou5f1/Oct-4 和 ZFP42/Rex-1，但未检测到 Nanog 转录本。流式细胞术和荧光分析显示存在具有胚胎和间充质细胞标志物的异质细胞群体。在化学定义的体外条件下培养两周后，可实现脂肪、软骨和成骨分化。此外，一些伸长的细胞自发获得收缩能力。
我们的研究结果进一步证实了牙髓是成体干细胞的重要来源，并鼓励对 mDPSC 在实验性疾病模型中的治疗潜力进行研究。
