Department of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology, 22 Zhongguancun Nandajie, Haidian District, Beijing 100081, China.
J Dent Res. 2013 May;92(5):450-5. doi: 10.1177/0022034513483471. Epub 2013 Mar 22.
We previously hypothesized that the development of traumatic temporomandibular joint (TMJ) ankylosis was similar to that of hypertrophic non-union. Besides similarities in etiology, hypertrophic bone stumps, and long-term development, the radiolucent zone, frequently located in the ankylosed bone, is another common feature. In this study, we demonstrated that the radiolucent zone also contained multilineage potential cells (RZs, radiolucent-zone-related cells) as the non-union tissues. RZs were characterized and compared with mandibular bone marrow stem cells (BMSCs) by analysis of MSC-related markers, colony-forming-unit assays, multipotential differentiation assays, alkaline phosphatase (ALP) activity assays, and cell transplantation in vivo. Both cell types were positive for CD105, CD166, and Stro-1 expression, negative for CD34 and CD45 expression, and exhibited osteogenic, adipogenic, and chondrogenic differentiation potentials. However, compared with mandibular BMSCs, RZs showed lower colony-forming-unit abilities and proliferation rates. The mineralization and bone-forming ability of RZs was weaker than that of mandibular BMSCs, with Runx2 and ALP mRNA expression and ALP activity significantly lower in RZs. All these results suggest that RZs possess the properties of MSCs but lower proliferation and osteogenic differentiation capacity similar to that of stromal cells in hypertrophic non-union tissues.
我们之前假设创伤性颞下颌关节（TMJ）强直的形成类似于肥大性骨不连。除了病因、肥大性骨残端和长期发展相似外，透光区也是另一个常见特征，通常位于强直的骨中。在这项研究中，我们证明了透光区也包含多能性细胞（RZ，与透光区相关的细胞），与非愈合组织一样。通过分析 MSC 相关标志物、集落形成单位测定、多能分化测定、碱性磷酸酶（ALP）活性测定和体内细胞移植，对 RZ 进行了表征并与下颌骨髓基质细胞（BMSC）进行了比较。两种细胞类型均对 CD105、CD166 和 Stro-1 表达呈阳性，对 CD34 和 CD45 表达呈阴性，并具有成骨、成脂和成软骨分化潜能。然而，与下颌 BMSC 相比，RZ 表现出较低的集落形成单位能力和增殖率。RZ 的矿化和成骨能力较弱，Runx2 和 ALP mRNA 表达及 ALP 活性明显低于下颌 BMSC。所有这些结果表明，RZ 具有 MSC 的特性，但增殖和成骨分化能力较低，类似于肥大性骨不连组织中的基质细胞。
