Employing a transgenic animal model to obtain cementoblasts in vitro
Employing a transgenic animal model to obtain cementoblasts in vitro
复制标题
DOI：
10.1902/jop.2000.71.1.63
复制
发表时间：
2000-01-01
影响因子：
4.3
通讯作者：
Somerman, MJ
中科院分区：
文献类型：
--
作者：
D'Errico, JA;Berry, JE;Somerman, MJ
背景：牙骨质是牙根表面的矿化组织，它的正确形成是形成功能性牙周膜所必需的。此外，健康牙骨质的存在被认为是预测因疾病而丢失的牙周组织修复的重要标准。尽管牙骨质对一般口腔健康具有重要意义，但控制牙骨质组织发育和再生的机制尚不清楚，缺乏合适的体外实验模型阻碍了研究。方法：从OC-Tag转基因小鼠的下颌第一磨牙根表面获得细胞，以建立成牙骨质细胞群体，而不产生含有牙周膜(PDL)细胞的异质性群体。这些小鼠在骨钙素(OC)启动子的控制下含有SV40大T抗原(Tag)。因此，只有表达OC的细胞也表达TAG，并在体外永生化。根据先前的原位研究结果，OC在根发育过程中由成牙骨质细胞表达，而不是由PDL内的细胞表达。因此，当使用胶原酶/胰酶消化法从发育中的磨牙分离细胞群时，只有成牙骨质细胞，而不是PDL细胞，被永生化，从而在培养中存活。结果：得到的永生化成牙骨质细胞群(OC/CM)表达骨涎蛋白(BSP)、骨桥蛋白(OPN)和OC，这些标记对牙根表面的细胞具有选择性。这些细胞还表达I型和XII型胶原以及I型PTH/PTHrP受体(PTH1R)。除了表达与成牙骨质细胞相关的基因外，OC/CM细胞还促进矿化结节的形成，并表现出PTHrP介导的cAMP反应。结论：这种体外建立成牙骨质细胞的方法为研究牙骨质形成提供了一个必要的模型，以增强我们对控制牙周组织发育、维持和再生机制的认识。
Background: Proper formation of cementum, a mineralized tissue lining the tooth root surface, is required for development of a functional periodontal ligament. Further, the presence of healthy cementum is considered to be an important criterion for predictable restoration of periodontal tissues lost as a consequence of disease. Despite the significance of cementum to general oral health, the mechanisms controlling development and regeneration of this tissue are not well understood and research has been hampered by the lack of adequate in vitro experimental models.Methods: In an effort to establish cementoblast cell populations, without the trappings of a heterogeneous population containing periodontal ligament (PDL) cells, cells were obtained from the root surface of first mandibular molars of OC-TAg transgenic mice. These mice contain the SV40 large T-antigen (TAg) under control of the osteocalcin (OC) promoter. Therefore, only cells that express OC also express TAg and are immortalized in vitro. Based on results of prior in situ studies, OC is expressed by cementoblasts during root development, but not by cells within the PDL. Consequently, when populations are isolated from developing molars using collagenase/trypsin digestion, only cementoblasts, not PDL cells, are immortalized and thus, will survive in culture.Results: The resulting immortalized cementoblast population (OC/CM) expressed bone sialoprotein (BSP), osteopontin (OPN), and OC, markers selective to cells lining the root surface. These cells also expressed type I and XII collagen and type I PTH/PTHrP receptor (PTH1R). In addition to expression of genes associated with cementoblasts, OC/CM cells promoted mineral nodule formation and exhibited a PTHrP mediated cAMP response.Conclusions: This approach for establishing cementoblasts in vitro provides a model to study cementogenesis as required to enhance our knowledge of the mechanisms controlling development, maintenance, and regeneration of periodontal tissues.