Emdogain-Gel Stimulates Signal Transduction of BMP and TGF-ƒÀ

Objective: Emdogain-Gel (Emd-Gel) containing Enamel matrix proteins promotes biomineralization such as osteogenesis and cementogenesis in the regeneration of periodontal tissues. However, growth factors for this activity in Emd-Gel, which is composed of enamel matrix proteins, remain unclear. Recently, it has been suggested that osteoinductive factors such as bone morphogenetic protein (BMP) and transforming growth factor-b (TGF-b) exist in enamel matrix. Therefore, we investigated osteoinductive growth factors in Emd-Gel using a luciferase reporter assay. Methods: Emd-gel was fractionated into 22 fractions with column of Sephadex G-100 equilibrated with 4 M guanidine solution (0.05 M Tris-HCl, pH 7.4). In each fraction, TGF-b and BMP were determined using the luciferase reporter gene conjugated by TGF-b-responsive PAI-1 promoter region (PAI-1-luc) and BMP-responsive Id1 promoter region (Id1-luc) respectively. Results: In unfractionated Emd-Gel, TGF-b-like activity was detected. However, BMP-like activity was not recognized. On the other hand, in fractionated Emd-Gel samples, TGF-b-like activity was detected from fraction numbers 8 to 13, and BMP-like activity was detected from fraction numbers 4 to 6. Also, BMP-like activity in Emd-Gel was confirmed to be inhibited by authentic TGF-b1 and TGF-b-like growth factor in Emd-Gel. Conclusion: These results indicate that Emd-Gel contains TGF-b and BMP-like growth factors that contribute to the induction of biomineralization in periodontal regeneration.