Molecular mechanisms of cementogenesis based on cementum marker

Objectives: The dental follicle is the mesenchymal tissue surrounding the developing tooth germ. During cementgenesis, progenitor cells present in the dental follicle are believed to play a central role in the formation of cementum. However, little is known about the biology of these progenitors. Methods: Previously, we have shown that cultured bovine dental follicle cells (BDFC) are able to form cementum matrix when transplanted into immunodeficient mice. The cementum matrix formed by BDFC was heavily stained following addition of anti-cementum specific monoclonal antibody (mAb 3G9). This antibody was raised against partially purified bovine cementum matrix containing cementum-derived attachment protein, and specifically recognizes cementum matrix and cementoblasts, but not other tissues such as bone matrix. These results support the presence of cementoblast progenitors in BDFC. To further analyze the biology of BDFC, we attempted to isolate cementoblast progenitors from immortalized BDFC through expression of the polycomb group protein, Bmi-1, and human telomerase reverse transcriptase (hTERT). Results: and Conclusions: From these cells, we established a clonal cell line, designated BCPB8, which formed cemetum-like tissue that was reactive to the mAb 3G9, and Sharpy's fiber-like structure. Alternatively they expressed mRNA for bone sialoprotein, osteocalcin, osteopontin and type I collagen upon implantation. These results indicated that the BCPB8 is the first immortalized clonal cell line of cementoblast progenitors, and could be a useful tool not only to study cementogenesis but also to develop regeneration therapy for patients with periodontitis.