scholarly journals Dental Enamel Development: Proteinases and Their Enamel Matrix Substrates

2013 ◽  
Vol 2013 ◽  
pp. 1-24 ◽  
Author(s):  
John D. Bartlett
Keyword(s):  
Dental Enamel ◽  
Tissue Expression ◽  
Detailed Examination ◽  
Null Mouse ◽  
Enamel Matrix ◽  
Crystallite Growth ◽  
Enamel Matrix Proteins ◽  
Critical Function ◽  
Proteinase Activation ◽  
Enamel Proteins

This review focuses on recent discoveries and delves in detail about what is known about each of the proteins (amelogenin, ameloblastin, and enamelin) and proteinases (matrix metalloproteinase-20 and kallikrein-related peptidase-4) that are secreted into the enamel matrix. After an overview of enamel development, this review focuses on these enamel proteins by describing their nomenclature, tissue expression, functions, proteinase activation, and proteinase substrate specificity. These proteins and their respective null mice and human mutations are also evaluated to shed light on the mechanisms that cause nonsyndromic enamel malformations termed amelogenesis imperfecta. Pertinent controversies are addressed. For example, do any of these proteins have a critical function in addition to their role in enamel development? Does amelogenin initiate crystallite growth, does it inhibit crystallite growth in width and thickness, or does it do neither? Detailed examination of the null mouse literature provides unmistakable clues and/or answers to these questions, and this data is thoroughly analyzed. Striking conclusions from this analysis reveal that widely held paradigms of enamel formation are inadequate. The final section of this review weaves the recent data into a plausible new mechanism by which these enamel matrix proteins support and promote enamel development.

Demonstration of an Alloimmune Response to Embryonic Enamel Matrix Proteins

1975 ◽  
Vol 54 (3_suppl) ◽  
pp. 72-77 ◽  
Author(s):  
Steven E. Schonfeld
Keyword(s):  
Young Adult ◽  
Specific Binding ◽  
Matrix Proteins ◽  
Antigenic Determinants ◽  
Enamel Matrix ◽  
Enamel Matrix Proteins ◽  
Incisor Tooth ◽  
Immunofluorescent Microscopy ◽  
Enamel Proteins ◽  
Indirect Immunofluorescent

Young adult rabbits were immunized with enamel matrix proteins from embryonic tooth organs of the same strain of rabbit. These proteins elicited an alloimmune response as demonstrated by the specific binding of antiserum to enamel matrix which was visualized by indirect immunofluorescent microscopy. The labial and lingual surfaces of embryonic incisor tooth organs were found to share common antigenic determinants. The observations suggest that enamel proteins could possibly be autoantigens.

Dental Enamel Matrix — Isolation and Partial Sequence of a Peptide Component

1979 ◽  
Vol 58 (2_suppl) ◽  
pp. 997-999 ◽  
Author(s):  
A.G. Fincham
Keyword(s):  
Amino Acid ◽  
Cyanogen Bromide ◽  
Dental Enamel ◽  
Disc Electrophoresis ◽  
Matrix Proteins ◽  
Partial Sequence ◽  
Enamel Matrix ◽  
Enamel Matrix Proteins ◽  
Peptide Component ◽  
Electrophoretic Component

Chromatography of demineralized bovine fetal enamel matrix proteins on 'Biogel P6' was shown to yield a trailing peak which contained a single electrophoretic component. This polypeptide, further purified by chromatography on Biogel P4', was found to be homogeneous by disc electrophoresis and gel isoelectric focussing. Amino acid analyses indicated this component (designated: 'E5') to be similar to some of the phosphopeptides previously described. Cyanogen bromide cleavage of E5 yielded three principal products whose amino acid compositions and N-terminal residues were investigated. A partial sequence for component E5 was proposed and comparison with previous bovine matrix isolates was made.

scholarly journals Proteinases in Developing Dental Enamel

1999 ◽  
Vol 10 (4) ◽  
pp. 425-441 ◽  
Author(s):  
J.D. Bartlett ◽  
J.P. Simmer
Keyword(s):  
Proteinase Inhibitors ◽  
Dental Enamel ◽  
Serine Proteinase ◽  
Organic Matrix ◽  
Enamel Organ ◽  
Maturation Stage ◽  
Enamel Matrix ◽  
Enamel Matrix Proteins ◽  
Early Maturation

For almost three decades, proteinases have been known to reside within developing dental enamel. However, identification and characterization of these proteinases have been slow and difficult, because they are present in very small quantities and they are difficult to purify directly from the mineralizing enamel. Enamel matrix proteins such as amelogenin, ameloblastin, and enamelin are cleaved by proteinases soon after they are secreted, and their cleavage products accumulate in the deeper, more mature enamel layers, while the full-length proteins are observed only at the surface. These results suggest that proteinases are necessary for "activating" enamel proteins so the parent proteins and their cleavage products may perform different functions. A novel matrix metalloproteinase named enamelysin (MMP-20) was recently cloned from tooth tissues and was later shown to localize primarily within the most recently formed enamel. Furthermore, recombinant porcine enamelysin was demonstrated to cleave recombinant porcine amelogenin at virtually all of the sites that have previously been described in vivo. Therefore, enamelysin is at least one enzyme that may be important during early enamel development. As enamel development progresses to the later stages, a profound decrease in the enamel protein content is observed. Proteinases have traditionally been assumed to degrade the organic matrix prior to its removal from the enamel. Recently, a novel serine proteinase named enamel matrix serine proteinase-1 (EMSP1) was cloned from enamel organ epithelia. EMSP1 localizes primarily to the early maturation stage enamel and may, therefore, be involved in the degradation of proteins prior to their removal from the maturing enamel. Other, as yet unidentified, proteinases and proteinase inhibitors are almost certainly present within the forming enamel and await discovery.

scholarly journals Enamelysin (Matrix Metalloproteinase 20)-deficient Mice Display an Amelogenesis Imperfecta Phenotype

2002 ◽  
Vol 277 (51) ◽  
pp. 49598-49604 ◽  
Author(s):  
John J. Caterina ◽  
Ziedonis Skobe ◽  
Joanne Shi ◽  
Yanli Ding ◽  
James P. Simmer ◽  
...  
Keyword(s):  
Matrix Metalloproteinase ◽  
Tooth Development ◽  
Developmental Time ◽  
Enamel Organ ◽  
Null Mouse ◽  
Enamel Matrix ◽  
Enamel Matrix Proteins ◽  
Time Period

Enamelysin is a tooth-specific matrix metalloproteinase that is expressed during the early through middle stages of enamel development. The enamel matrix proteins amelogenin, ameloblastin, and enamelin are also expressed during this same approximate developmental time period, suggesting that enamelysin may play a role in their hydrolysis. In support of this interpretation, recombinant enamelysin was previously demonstrated to cleave recombinant amelogenin at virtually all of the precise sites known to occurin vivo. Thus, enamelysin is likely an important amelogenin-processing enzyme. To characterize thein vivobiological role of enamelysin during tooth development, we generated an enamelysin-deficient mouse by gene targeting. Although mice heterozygous for the mutation have no apparent phenotype, the enamelysin null mouse has a severe and profound tooth phenotype. Specifically, the null mouse does not process amelogenin properly, possesses an altered enamel matrix and rod pattern, has hypoplastic enamel that delaminates from the dentin, and has a deteriorating enamel organ morphology as development progresses. Our findings demonstrate that enamelysin activity is essential for proper enamel development.

scholarly journals Functions of KLK4 and MMP-20 in dental enamel formation

2008 ◽  
Vol 389 (6) ◽  
Author(s):  
Yuhe Lu ◽  
Petros Papagerakis ◽  
Yasuo Yamakoshi ◽  
Jan C.-C. Hu ◽  
John D. Bartlett ◽  
...  
Keyword(s):  
Autosomal Recessive ◽  
Dental Enamel ◽  
Organic Matrix ◽  
Maturation Stage ◽  
Protein Cleavage ◽  
Enamel Formation ◽  
Residual Protein ◽  
Kallikrein 4 ◽  
Enamel Protein ◽  
Enamel Proteins

Abstract Two proteases are secreted into the enamel matrix of developing teeth. The early protease is enamelysin (MMP-20). The late protease is kallikrein 4 (KLK4). Mutations in MMP20 and KLK4 both cause autosomal recessive amelogenesis imperfecta, a condition featuring soft, porous enamel containing residual protein. MMP-20 is secreted along with enamel proteins by secretory-stage ameloblasts. Enamel protein-cleavage products accumulate in the space between the crystal ribbons, helping to support them. MMP-20 steadily cleaves accumulated enamel proteins, so their concentration decreases with depth. KLK4 is secreted by transition- and maturation-stage ameloblasts. KLK4 aggressively degrades the retained organic matrix following the termination of enamel protein secretion. The principle functions of MMP-20 and KLK4 in dental enamel formation are to facilitate the orderly replacement of organic matrix with mineral, generating an enamel layer that is harder, less porous, and unstained by retained enamel proteins.

Effects of enamel matrix proteins on multi-lineage differentiation of periodontal ligament cells in vitro

2013 ◽  
Vol 9 (1) ◽  
pp. 4796-4805 ◽  
Author(s):  
Harsh D. Amin ◽  
Irwin Olsen ◽  
Jonathan C. Knowles ◽  
Michel Dard ◽  
Nikolaos Donos
Keyword(s):  
Periodontal Ligament ◽  
Matrix Proteins ◽  
Periodontal Ligament Cells ◽  
Enamel Matrix ◽  
Enamel Matrix Proteins ◽  
Lineage Differentiation

scholarly journals Enamel-like tissue regeneration by using biomimetic enamel matrix proteins

2021 ◽  
Author(s):  
Zehui Fang ◽  
Mengxi Guo ◽  
Qingli Zhou ◽  
Quanli Li ◽  
Hai Ming Wong ◽  
...  
Keyword(s):  
Tissue Regeneration ◽  
Matrix Proteins ◽  
Enamel Matrix ◽  
Enamel Matrix Proteins

Correlation of Apical and Lateral Membrane Modulations of Maturation Ameloblasts

1985 ◽  
Vol 64 (8) ◽  
pp. 1055-1061 ◽  
Author(s):  
Z. Skobe ◽  
F. LaFrazia ◽  
K. Prostak
Keyword(s):  
Apical Membrane ◽  
Apical Cell ◽  
Matrix Proteins ◽  
Maturation Stage ◽  
Enamel Matrix ◽  
Enamel Matrix Proteins ◽  
Rat Incisor ◽  
Lateral Membrane ◽  
Apical Junctions ◽  
Scanning Electron

Maturation ameloblasts of rat incisor teeth have smooth-ended and ruffle-ended apical membrane configurations. It has also been reported that maturation ameloblasts have several lateral membrane configurations. The purpose of this study was to determine the correlation between the modulations of lateral and apical cell membranes of murine incisor ameloblasts in the maturation stage of amelogenesis. Maxillary and mandibular incisors were dissected, demineralized, embedded in paraffin, sectioned and then de-paraffinized, and the enamel organs were prepared for scanning electron microscopy. Additional mouse and rat incisor enamel organs were fixed and teased apart during dehydration, then observed in the SEM. The lengths of smooth- and ruffle-ended ameloblast segments were measured, and the site, length, and frequency of each lateral membrane configuration were determined within each segment. The lateral membrane configuration with folds forming from 12 to 14 channels around the periphery of the cells was most predominant in both smooth- and ruffle-ended cells. Cells surrounded by from six to eight channels were the only other lateral membrane configuration observed in ruffle-ended ameloblasts. Smooth-ended ameloblasts had lateral membrane configurations with either dense or sparse microvillous projections in addition to both types of channel cells. The observation that channelled extracellular spaces are always associated with ruffle-ended cells suggests that channels somehow function in conjunction with the ruffled apical membrane in resorption and removal of enamel matrix proteins. The smooth-ended ameloblasts lack tight apical junctions, and their microvillous lateral membranes permit the passage of plasma fluids around cells to the maturing enamel surface. Analysis of our data indicates that specific lateral membrane configurations are related to the type of apical membrane present.

scholarly journals Effect of enamel matrix proteins on the treatment of intrabony defects: a split-mouth randomized controlled trial study

2007 ◽  
Vol 21 (3) ◽  
pp. 241-246 ◽  
Author(s):  
Daniela Chambrone ◽  
Ivan Munhoz Pasin ◽  
Marina Clemente Conde ◽  
Claudio Panutti ◽  
Silvia Carneiro ◽  
...  
Keyword(s):  
Randomized Controlled Trial ◽  
Controlled Trial ◽  
Matrix Proteins ◽  
Treatment Modalities ◽  
Enamel Matrix ◽  
Intrabony Defects ◽  
Enamel Matrix Proteins ◽  
Pocket Depth ◽  
Randomized Controlled ◽  
Significant Difference

The objective of this split-mouth, double-blind, randomized controlled trial was to compare the clinical effect of treatment of 2- or 3-wall intrabony defects with open flap debridement (OFD) combined or not with enamel matrix proteins (EMP). Thirteen volunteers were selected with one pair of or more intrabony defects and probing pocket depth (PPD) > 5 mm. All individuals received instructions regarding oral hygiene and were submitted to scaling and root planing. Each participant received the two treatment modalities: test sites were treated with OFD and EMP, and control sites received only OFD. After 6 months, a significant reduction was observed in PPD for the EMP group (from 6.42 ± 1.08 mm to 2.67 ± 1.15 mm) and for the OFD group (from 6.08 ± 1.00 mm to 2.00 ± 0.95 mm) (p < 0.0001), but with no significant difference between groups (p = 0.13). A significant gain in relative attachment level (RAL) was observed in both groups (EMP: from 13.42 ± 1.88 mm to 10.75 ± 2.26 mm, p < 0.001; OFD: from 12.42 ± 1.98 mm to 10.58 ± 2.23 mm, p = 0.013), but with no significant difference between groups (p = 0.85). Gingival recession (GR) was higher in the EMP group (from 1.08 ± 1.50 mm to 2.33 ± 1.43 mm; p = 0.0009) than in the OFD group (from 0.66 ± 1.15 mm to 1.16 ± 1.33 mm; p = 0.16), but this difference was not significant (p = 0.06). In conclusion, the results showed that OFD combined with EMP was not able to improve treatment of intrabony defects compared to OFD alone.

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