Isolation and Functional Analysis of an Immortalized Murine Cementocyte Cell Line, IDG-CM6

• DOI: 10.1002/jbmr.2690
• Publication Date: 2015-08-14T23:01:39Z
• Authors: Ning Zhao; Francisco H Nociti; Peipei Duan; Matthew Prideaux; Hong Zhao; Brian L Foster; Martha J Somerman; Lynda F Bonewald
• Keywords: DMP1; Osteocyte; Cementoblast; Sclerostin; Bone remodeling

ABSTRACT The dental cementum covering the tooth root is similar to bone in several respects but remains poorly understood terms of development and differentiation cementoblasts, as well potential function(s) cementocytes residing cellular cementum. It not known if cementocyte a dynamic actor metabolism, comparable osteocyte bone. Cementocytes exhibit irregular spacing lacunar shape, with fewer canalicular connections compared osteocytes. Immunohistochemistry quantitative PCR (qPCR) revealed that vivo expression profile paralleled osteocytes, including dentin matrix protein 1 (Dmp1/DMP1), Sost/sclerostin, E11/gp38/podoplanin, Tnfrsf11b (osteoprotegerin [OPG]), Tnfsf11 (receptor activator NF-κB ligand [RANKL]). We used Immortomouse+/−; Dmp1-GFP+/− mice isolate Dmp1-expressing cells followed by immortalization using interferon (IFN)-γ-inducible promoter driving thermolabile large T antigen create first immortalized line cementocytes, IDG-CM6. This cell reproduced observed vivo, alkaline phosphatase activity mineralization. IDG-CM6 expressed higher levels lower IDG-SW3 under fluid flow shear stress, significantly increased OPG while decreasing RANKL, leading OPG/RANKL ratio, which would inhibit osteoclast activation. These studies indicate similarities yet potentially important differences function osteocytes support mechanically responsive cells. © 2015 American Society for Bone Mineral Research.