Noggin Blocks Osteoinductive Activity of Porcine Enamel Extracts

Abstract

Enamel extracts induce biomineralization such as osteogenesis and cementogenesis, but the molecular component responsible for this activity remains uncertain. We fractionated enamel extracts from developing pig teeth and isolated the osteoinductive fraction. Proteins from pig enamel scrapings were extracted under alkaline conditions (pH 10.8) and fractionated with the use of a Sephadex G-100 (size exclusion) column. The ability of each fraction to enhance alkaline phosphatase (ALP) activity was assayed in ST2 cells, a mouse bone marrow stromal cell line. The osteoinductive fraction of enamel extracts (OFE) was found in fractions 44 and 45, which induced ST2 cells to express the phenotype of bone-forming osteoblasts, and to form mineralized nodules. Furthermore, the ALP activity of ST2 cells exposed to OFE was reduced by noggin, an antagonist of BMPs, and OFE reacted with BMP-2/4 antibody in dot-blot analysis. These results indicate that OFE contains BMPs that contribute to the induction of biomineralization.

Heterodimeric BMP-2/7 Antagonizes the Inhibition of All-Trans Retinoic Acid and Promotes the Osteoblastogenesis

“…The medium was replaced every 3 days. On the 21 st and 28 th day, mineralized nodules were determined by the staining of alizarin red (Sigma-Aldrich, St. Louis, MO, USA) as previously described [25], [26]. Culture plates were photographed by NIS-Elements F2.20 (Nikon Eclipse 80i, Tokyo, Japan), and the calcified areas were then quantified using a software of Image-Pro Plus 6.0.…”

Enamel matrix protein derivatives: role in periodontal regeneration

“…Although early immunoassay studies could not identify the presence of growth factors in EMD,16 nominal levels of transforming growth factor β1 have been detected immunologically 17. In addition, by using noggin, a bone morphogenic protein (BMP)-binding protein, investigators have identified BMP-2 and BMP-4 in an osteoinductive fraction of enamel extracts 18. A wide range of in vitro and in vivo studies have demonstrated that EMD and amelogenins stimulate growth of multiple mesenchymal cell types including fibroblasts, cementoblasts, osteoblasts, and stem cells 19,20.…”

The Effect of an Enamel Matrix Derivative (Emdogain) Combined with Bone Ceramic on Bone Formation in Mandibular Defects: A Histomorphometric and Immunohistochemical Study in the Canine

“…Emdogain is a commercially available mixture of EMDs. The composition of EMDs has been described as a hydrophobic enamel matrix protein complex derived from 6-month-old porcine tooth buds containing more than 90% amelogenin as well as enamelin, tuftelin, tuft proteins, ameloblastin [40], and other peptides such as bone morphogenetic proteins (BMPs) and transforming growth factor-beta (TGF- β ) [41, 42]. It has been known that amelogenins are self-assembled into supermolecular aggregates, which are generated in insoluble extracellular matrix [43] with high affinity for collagens and HA [44, 45].…”