Amelogenins regulate expression of genes associated with cementoblasts in vitro

Abstract

Amelogenins are major proteins expressed by ameloblasts during development of the crown (enamel and dentin). These matrix proteins guide crystal habits of the mineral phase of developing enamel and are possible regulators of other genes/proteins during development and maturation of crown and root (dentin and cementum). This study focused on defining the effect that a specific proteolytic cleavage product of amelogenin, tyrosine-rich amelogenin peptide (TRAP), has on cementoblast behavior. Immortalized cementoblasts (OCCM-30) were exposed to TRAP in vitro. Cells treated with TRAP were evaluated for cell proliferation, gene expression for osteocalcin (OCN), osteopontin (OPN), and bone sialoprotein (BSP), and induction of mineral nodule formation. No significant difference in cell proliferation was found between vehicle-treated cells and those treated with TRAP for up to 9 d after treatment. Gene expression of OCN, OPN, and BSP in TRAP-treated cementoblasts showed down-regulation, up-regulation, and no significant change, respectively, relative to vehicle control. A marked decrease in mineral nodule formation was found in cells treated with TRAP compared with the vehicle control, in a dose-dependent manner. These data, along with our previous results demonstrating similar activity with full-length amelogenin and leucine-rich amelogenin peptide (LRAP), suggest that amelogenin-like molecules regulate mesenchymal cell behavior.

Amelogenin Peptide Extract Increases Differentiation and Angiogenic and Local Factor Production and Inhibits Apoptosis in Human Osteoblasts

“…Our results indicate that amelogenin and Fraction C have no effect on cell number in either MG63 cells or human osteoblasts, which is in agreement with the previously published literature [52][53][54][55][56]. Our results suggest that osteoblast maturation was promoted at the expense of cell proliferation.…”

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

“…The proper role of amelogenins in periodontal development and regeneration remains questionable, even if the observation that amelogenin-null mice have abnormal cementum suggests that amelogenins play a role in cementogenesis (Viswanathan et al 2003). Because the biological effects of recombinant amelogenins on the expression of extra-cellular matrix makers of periodontal cells and in vitro wound healing show discrepancies compared with EMD (Shimizu et al 2005;Tompkins and Veis 2002;Swanson et al 2006;Chong et al 2006), amelogenin might not be able to "summarize" the biological action of EMD. Future studies are needed to identify the part that other non-BMP components present in EMD play in cell differentiation .…”

Mechanical Tensile Stress Effects on the Expression of Bone Sialoprotein in Bovine Cementoblasts

“…8 Expression of BSP in the cementoblast is regulated by amelogenins in vitro, basic fibroblast growth factors, and structure or compositional changes in root surface matrix components. [17][18][19][20][21] Mechanical stimuli and up-regulated BSP expression in osteoblasts have been previously demonstrated. 9,20,22 However, no data are yet available on the effects of mechanical tensile stress on the expression of mineralization of related genes in cementoblasts.…”