In vitro Effects of Enamel Matrix Proteins on Rat Bone Marrow Cells and Gingival Fibroblasts

Abstract

Emdogain (EMD), a formulation of Enamel Matrix Proteins (EMP), is used clinically for periodontal regeneration, where it stimulates cementum formation and promotes gingival healing. In this study, we investigated the in vitro effects of EMD on rat bone marrow stromal cells (BMSC) and gingival fibroblasts (GF). EMD (at 25 micro g/mL) increased the osteogenic capacity of bone marrow, as evidenced by approximately three-fold increase in BMSC cell number and approximately two-fold increase in alkaline phosphatase (ALP) activity and mineralized nodule formation. The presence of EMD in the initial stages (first 48 hrs) of the culture was crucial for this effect. In contrast, EMD did not induce osteoblastic differentiation of GF (evidenced by lack of mineralization or ALP activity) but increased up to two-fold both their number and the amount of matrix produced. These in vitro data on BMSC and GF could explain the promotive effect of EMD on bone formation and connective tissue regeneration, respectively.

Human dental follicle cells acquire cementoblast features under stimulation by BMP-2/-7 and enamel matrix derivatives (EMD) in vitro

“…EMD have recently been shown to induce cementoblast differentiation and periodontal regeneration in vivo (Bosshardt et al 2005) and are suggested to enhance cell proliferation, migration adhesion, and differentiation in vitro (Gestrelius et al 1997;Rincon et al 2005). In addition, EMD increase alkaline phosphatase (AP) activity and matrix mineralization in human periodontal ligament cells and osteoblasts and in rodent bone marrow stromal cells (Van der Pauw et al 2000;Keila et al 2004). Furthermore, EMD can regulate mouse follicle cell differentiation toward the osteo-cementoblastic phenotype (Hakki et al 2001).…”

A Three-Dimensional Cell Culture Model to Study the Mechano-Biological Behavior in Periodontal Ligament Regeneration

“…24,25 This indicates that the presence of EMD on PDL cell differentiation is crucial in the initial stages of culture. 26 The relatively low response might be associated with the dosage and application method in our 3D mode, as the effect was not as obvious in 2D culture systems. On the other hand, the in vivo situation is also 3D; thus, 2D systems might exaggerate and overstate the actual effect of EMD.…”

Amelogenin binds to both heparan sulfate and bone morphogenetic protein 2 and pharmacologically suppresses the effect of noggin

“…On the other hand, though there is no known clinical report showing that amelogenin causes bone diseases, in vitro experiment results have provided some indications of its function in bone formation. For example, 6 leucine-rich amelogenin peptide (LRAP) is expressed in cementoblasts/periodontal ligament cells and regulates osteoclastogenesis [13], and was shown to down-regulate osteocalcin, a marker of bone turnover [14,15]. In another study, amelogenin decreased the levels of RANKL, M-CSF, and fibronectin in osteoblasts [16].…”

“…A recent clinical review reported that EMD promotes both cementogenesis [1] and osteogenesis [2], while it has also been shown that EMD has bone morphogenetic protein (BMP) and transforming growth factor-β (TGF-β) activities [3,4], while in vitro experiments demonstrated that it stimulates osteoblast proliferation and differentiation [5,6]. EMD consists of amelogenin at nearly 90%, along with other enamel matrix proteins, such as enamelin, tuftelin, amelin, and ameloblastin [7,8].…”