Isolation and Functional Analysis of an Immortalized Murine Cementocyte Cell Line, IDG-CM6.
Isolation and Functional Analysis of an Immortalized Murine Cementocyte Cell Line, IDG-CM6.
复制标题
DOI：
10.1002/jbmr.2690
复制
发表时间：
2016-02
期刊：
影响因子：
--
通讯作者：
Bonewald LF
中科院分区：
文献类型：
--
作者：
Zhao N;Nociti FH Jr;Duan P;Prideaux M;Zhao H;Foster BL;Somerman MJ;Bonewald LF
覆盖在牙根上的牙骨质在某些方面与骨相似，但就成牙骨质细胞的发育和分化以及细胞牙骨质中牙骨质细胞的潜在功能(S)而言，人们仍然知之甚少。目前尚不清楚牙骨质细胞是否是牙骨质代谢的动态参与者，可以与骨骼中的骨细胞相比较。牙骨质细胞具有不规则的间距和腔隙形状，与骨细胞相比，小管连接较少。免疫组织化学和定量聚合酶链式反应(QPCR)显示牙本质基质蛋白1(Dmp1/DMP1)、Sost/skerostin、E11/gp38/podoplan in、Tnfrsf11b(骨保护素；OPG)和Tnfsf11(核因子-kB受体激活剂；RANKL)在牙骨质细胞中的表达与骨细胞相似。我们使用Immortomouse+/−；Dmp1-gfp+/−小鼠分离牙骨质细胞作为DMP1表达细胞，然后使用干扰素诱导的启动子驱动不耐热的大T抗原的表达来永生化，建立了第一个牙骨质细胞永生化系IDG-γ。该细胞系复制了在体内观察到的牙骨质细胞的表达谱，包括碱性磷酸酶活性和矿化。与IDG-SW3细胞相比，IDG-CM6细胞表达更高水平的Tnfrsf11b和更低水平的Tnfsf11，在流体剪切力作用下，IDG-CM6细胞显著增加OPG而降低RANKL，导致OPG/RANKL比值显著增加，从而抑制破骨细胞的激活。这些研究表明，与骨细胞和支持牙骨质细胞作为机械反应细胞相比，牙骨质细胞的功能相似，但也存在潜在的重要差异。
The dental cementum covering the tooth root is similar to bone in several respects, but remains poorly understood in terms of development and differentiation of cementoblasts, as well as the potential function(s) of cementocytes residing in the cellular cementum. It is not known if the cementocyte is a dynamic actor in cementum metabolism, comparable to the osteocyte in the bone. Cementocytes exhibit irregular spacing and lacunar shape, with fewer canalicular connections compared to osteocytes. Immunohistochemistry and quantitative PCR (qPCR) revealed that the in vivo expression profile of cementocytes paralleled that of osteocytes, including expression of dentin matrix protein 1 (Dmp1/DMP1), Sost/sclerostin, E11/gp38/podoplanin, Tnfrsf11b (osteoprotegerin; OPG), and Tnfsf11 (receptor activator of NF-kB ligand; RANKL). We used the Immortomouse+/−; Dmp1-GFP+/− mice to isolate cementocytes as Dmp1-expressing cells followed by immortalization using the interferon (IFN)-γ-inducible promoter driving expression of a thermolabile large T antigen to create the first immortalized line of cementocytes, IDG-CM6. This cell line reproduced the expression profile of cementocytes observed in vivo, including alkaline phosphatase activity and mineralization. IDG-CM6 cells expressed higher levels of Tnfrsf11b, and lower levels of Tnfsf11 compared to IDG-SW3 osteocytes, and under fluid flow shear stress, IDG-CM6 cells significantly increased OPG while decreasing RANKL, leading to a significantly increased OPG/RANKL ratio, which would inhibit osteoclast activation. These studies indicate similarities yet potentially important differences in the function of cementocytes as compared to osteocytes and support cementocytes as mechanically responsive cells.