Matrix Genes and Enamel Formation

Author(s):  
J. D. Termine ◽  
M. F. Young
Keyword(s):  
2008 ◽  
Vol 389 (6) ◽  
Author(s):  
Yuhe Lu ◽  
Petros Papagerakis ◽  
Yasuo Yamakoshi ◽  
Jan C.-C. Hu ◽  
John D. Bartlett ◽  
...  

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.


2005 ◽  
Vol 280 (24) ◽  
pp. 23194-23202 ◽  
Author(s):  
Kaori Kubota ◽  
Daniel H. Lee ◽  
Masahiro Tsuchiya ◽  
Conan S. Young ◽  
Eric T. Everett ◽  
...  

2004 ◽  
Vol 231 (2) ◽  
pp. 432-440 ◽  
Author(s):  
Johanna Pispa ◽  
Tuija Mustonen ◽  
Marja L. Mikkola ◽  
Aapo T. Kangas ◽  
Petra Koppinen ◽  
...  

2005 ◽  
Vol 13 (3) ◽  
pp. 212-217 ◽  
Author(s):  
Maria Cristina Leme Godoy dos Santos ◽  
Sergio Roberto Peres Line

A melogenesis imperfecta (AI) is a group of inherited defects of dental enamel formation that show both clinical and genetic heterogeneity. Enamel findings in AI are highly variable, ranging from deficient enamel formation to defects in the mineral and protein content. Enamel formation requires the expression of multiple genes that transcribes matrix proteins and proteinases needed to control the complex process of crystal growth and mineralization. The AI phenotypes depend on the specific gene involved, the location and type of mutation, and the corresponding putative change at the protein level. Different inheritance patterns such as X-linked, autosomal dominant and autosomal recessive types have been reported. Mutations in the amelogenin, enamelin, and kallikrein-4 genes have been demonstrated to result in different types of AI and a number of other genes critical to enamel formation have been identified and proposed as candidates for AI. The aim of this article was to present an evaluation of the literature regarding role of proteins and proteinases important to enamel formation and mutation associated with AI.


2020 ◽  
Author(s):  
Xueyan Li ◽  
DI LIU ◽  
Sun Yang ◽  
Jingyun Yang ◽  
Youcheng Yu

Previous studies have reported the association between multiple genetic variants in enamel formation-related genes and the risk of dental caries with inconsistent results. We performed a systematic literature search of the PubMed, Cochrane Library, HuGE and Google Scholar databases for studies published before March 21, 2020 and conducted meta-, gene-based and gene-cluster analysis on the association between genetic variants in enamel- formation-related genes and the risk of dental caries. Our systematic literature search identified 21 relevant publications including a total of 24 studies for analysis. The genetic variant rs17878486 in AMELX was significantly associated with dental caries risk (OR=1.40, 95% CI: 1.02-1.93, P=0.037). We found no significant association between the risk of dental caries with rs12640848 in ENAM (OR=1.15, 95% CI: 0.88-1.52, P=0.310), rs1784418 in MMP20 (OR=1.07, 95% CI: 0.76-1.49, P=0.702) and rs3796704 in ENAM (OR=1.06, 95% CI: 0.96-1.17, P=0.228). Gene-based analysis indicated that multiple genetic variants in AMELX showed joint association with the risk of dental caries (6 variants; P<10-5), so did genetic variants in MMP13 (3 variants; P=0.004), MMP2 (3 variants; P<10-5), MMP20 (2 variants; P<10-5) and MMP3 (2 variants; P<10-5). The gene-cluster analysis indicated a significant association between the genetic variants in this enamel-formation gene cluster and the risk of dental caries (P<10-5). The present meta-analysis revealed that genetic variant rs17878486 in AMELX were associated with dental caries, and multiple genetic variants in enamel-formation-related genes jointly contribute to the risk of dental caries, supporting the role of genetic variants in the enamel-formation genes in the etiology of dental caries.


2008 ◽  
Vol 135 (3) ◽  
pp. 362-365 ◽  
Author(s):  
Sarah A. Martin ◽  
Debbie Guatelli-Steinberg ◽  
Paul W. Sciulli ◽  
Phillip L. Walker

2016 ◽  
Vol 32 (3) ◽  
pp. 601-610 ◽  
Author(s):  
Takashi Nakamura ◽  
Lucia Jimenez-Rojo ◽  
Eiki Koyama ◽  
Maurizio Pacifici ◽  
Susana de Vega ◽  
...  

1957 ◽  
Vol s3-98 (43) ◽  
pp. 349-367
Author(s):  
D.F. G. POOLE

A number of features of enamel formation in the lizard Agama atricollis are described. The behaviour and properties of the ameloblasts indicate that the process of enamel formation is similar to the corresponding process in mammals; the fibrous enamel matrix appears to be formed from outgrowths of the cytoplasm of these cells. Interprismatic material, as it is known in mammals, is not produced, so that reptilian matrix tends to be uniformly fibrous. Nevertheless, the fibres are initially arranged in groups corresponding to the ameloblasts. There is no distinct pre-enamel stage because matrix production is immediately followed by a limited influx of mineral in an elementary state, converting the matrix into an basiphil form. Striae of Retzius may be due to periodic pauses in the normal process of matrix production enabling the ameloblasts to assimilate and secrete mineral. Before the onset of final calcification, the matrix seems to undergo a modification rendering it capable of influencing the size and orientation of mineral crystallites. The organic matrix has a refractive index of 1.57 and has no intrinsic birefringence. However, in suitable liquids the parallel fibres produce a positive form birefringence. If paraffin wax is allowed to crystallize on the matrix, optically negative streaks are formed parallel with the fibres, perhaps as the result of crystal overgrowth. Evidence obtained indicates that this reptilian type of ectodermal enamel is a likely precursor of the mammalian prismatic type. The evolution from one to the other could have been achieved in a comparatively simple step.


Author(s):  
James P. Simmer ◽  
Yuanyuan Hu ◽  
Amelia S. Richardson ◽  
Jan C.C. Hu

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