Laboratory of Stem Cell Biology in Dentistry-LABITRON, Oral and Maxillofacial Pathology Department, School of Dentistry, University of São Paulo, São Paulo, São Paulo, Brazil.
Laboratory of Stem Cell Biology in Dentistry-LABITRON, Oral and Maxillofacial Pathology Department, School of Dentistry, University of São Paulo, São Paulo, São Paulo, Brazil.
J Endod. 2018 Nov;44(11):1671-1676. doi: 10.1016/j.joen.2018.08.005.
Dental pulp is a complex tissue with highly differentiated cells, which makes its reconstruction a challenging task. The apical papilla is an undifferentiated tissue considered as the remnant of the dental papilla that forms the dentin-pulp complex. Aiming to analyze morphologic features of the tissue formed in an in vivo pulp model, we used human apical papilla as a cell source without the use of exogenous growth factors.
A construct was built using newborn mice molar crowns treated with TrypLE (Fisher Scientific, Loughborough, UK) and EDTA. The crowns were filled with PuraMatrix (Corning Inc, Corning, NY) and a pool population of human apical papilla cells. As a control, we used crowns filled only with PuraMatrix and empty crowns. The constructs were transplanted under severe combined immunodeficient mice kidney capsules. Immunohistochemistry for lamin A, dentin sialophosphoprotein, and dentin matrix protein 1 was performed.
Morphologic analysis of all transplanted crowns showed the formation of a loose connective tissue of variable cellularity with the presence of well-formed functional vessels. In the study group, lamin A-positive cells represented the majority of cells within the pulp chamber and a few cells in the vessel lining. We also found positivity for dentin sialophosphoprotein and dentin matrix protein 1, an indicator of odontoblast differentiation.
In our study model, human transplanted apical papilla cells mixed with the host cells and formed a vascularized viable tissue, and these cells were able to differentiate into odontoblastlike cells without the use of exogenous growth factors.
牙髓是一种具有高度分化细胞的复杂组织，因此其重建是一项具有挑战性的任务。根尖乳头是一种未分化的组织，被认为是形成牙本质-牙髓复合体的牙髓乳头的残余物。本研究旨在分析在体内牙髓模型中形成的组织的形态学特征，我们使用人根尖乳头作为细胞来源，而不使用外源性生长因子。
使用经 TrypLE（Fisher Scientific，Loughborough，英国）和 EDTA 处理的新生小鼠磨牙牙冠构建构建体。牙冠内填充 PuraMatrix（康宁公司，康宁，纽约）和人根尖乳头细胞的混合细胞悬液。作为对照，我们仅使用 PuraMatrix 填充牙冠和空牙冠。构建体被移植到严重联合免疫缺陷小鼠肾包膜下。进行层粘连蛋白 A、牙本质涎磷蛋白和牙本质基质蛋白 1 的免疫组织化学染色。
所有移植牙冠的形态学分析显示，形成了具有可变细胞数量的疏松结缔组织，并有形成良好的功能性血管。在研究组中，层粘连蛋白 A 阳性细胞代表牙髓腔内的大多数细胞，以及血管衬里中的少数细胞。我们还发现牙本质涎磷蛋白和牙本质基质蛋白 1 的阳性，这是成牙本质细胞分化的标志物。
在我们的研究模型中，人移植的根尖乳头细胞与宿主细胞混合形成了血管化的存活组织，这些细胞能够在不使用外源性生长因子的情况下分化为成牙本质细胞样细胞。
