scholarly journals The genetics of amelogenesis imperfecta: a review of the literature

2005 ◽  
Vol 13 (3) ◽  
pp. 212-217 ◽  
Author(s):  
Maria Cristina Leme Godoy dos Santos ◽  
Sergio Roberto Peres Line
Keyword(s):  
Autosomal Recessive ◽  
Autosomal Dominant ◽  
Dental Enamel ◽  
Matrix Proteins ◽  
Specific Gene ◽  
Enamel Formation ◽  
Complex Process ◽  
Different Types ◽  
Kallikrein 4

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.

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.

Association of hereditary thrombocythemia and distal limb defects with a thrombopoietin gene mutation

Blood ◽  
2009 ◽  
Vol 114 (8) ◽  
pp. 1655-1657 ◽  
Author(s):  
Claudio Graziano ◽  
Simona Carone ◽  
Emanuele Panza ◽  
Flora Marino ◽  
Pamela Magini ◽  
...  
Keyword(s):  
Human Development ◽  
Gene Mutation ◽  
Autosomal Dominant ◽  
Specific Gene ◽  
Autosomal Dominant Disorder ◽  
Distal Limb ◽  
Limb Defects ◽  
First Report

Abstract Hereditary thrombocythemia is a rare autosomal dominant disorder caused by mutations in either the thrombopoietin gene (TPO) or its receptor c-MPL. TPO mutations described so far lead to thrombopoietin overproduction through increased translation of m-RNA. Unilateral transverse reduction limb defects are usually sporadic and generally thought to be caused by vascular disruptions. Reports of inherited unilateral limb defects are extremely rare. In the present study, we describe a family with segregation of G185T TPO mutation in the 5′ UTR region in 4 subjects with thrombocythemia. Three of these patients also present congenital transverse limb defects. Association of these events gives a strong hint of the in vivo involvement of thrombopoietin in vasculogenesis, confirming the role of TPO in human development of the hemangioblast, the embryonic progenitor of the hematopoietic and endothelial lineages. This is the first report showing that vascular disruptions could be secondary to specific gene derangements.

11 Role of KLK4 in Dental Enamel Formation

2012 ◽  
Author(s):  
James P. Simmer ◽  
Yuanyuan Hu ◽  
Amelia S. Richardson ◽  
Jan C.C. Hu
Keyword(s):  
Dental Enamel ◽  
Enamel Formation

scholarly journals Premature Stop Codon in MMP20 Causing Amelogenesis Imperfecta

2008 ◽  
Vol 87 (1) ◽  
pp. 56-59 ◽  
Author(s):  
P. Papagerakis ◽  
H.-K. Lin ◽  
K.Y. Lee ◽  
Y. Hu ◽  
J.P. Simmer ◽  
...  
Keyword(s):  
Autosomal Recessive ◽  
Proteolytic Enzymes ◽  
Stop Codon ◽  
Translation Termination ◽  
Premature Stop Codon ◽  
Dental Enamel ◽  
Amino Acid Position ◽  
Amelogenesis Imperfecta ◽  
Exon 1 ◽  
Kallikrein 4

Proteolytic enzymes are necessary for the mineralization of dental enamel during development, and mutations in the kallikrein 4 ( KLK4) and enamelysin ( MMP20) genes cause autosomal-recessive amelogenesis imperfecta (ARAI). So far, only one KLK4 and two MMP20 mutations have been reported. We have identified an ARAI-causing point mutation (c.102G>A, g.102G>A, and p.W34X) in exon 1 of MMP20 in a proband with autosomal-recessive hypoplastic-hypomaturation amelogenesis imperfecta. The G to A transition changes the tryptophan (W) codon (TGG) at amino acid position 34 into a translation termination (X) codon (TGA). No disease-causing sequence variations were detected in KLK4. The affected enamel is thin, with mild spacing in the anterior dentition. The enamel layer is hypomineralized, does not contrast with dentin on radiographs, and tends to chip away from the underlying dentin. An intrinsic yellowish pigmentation is evident, even during eruption. The phenotype supports current ideas concerning the function of enamelysin.

scholarly journals Connective Tissue Growth Factor in Normal and Pathological Processes

2020 ◽  
Vol 10 (4) ◽  
pp. 254-261
Author(s):  
S. V. Topolyanskaya
Keyword(s):  
Growth Factor ◽  
Connective Tissue ◽  
Connective Tissue Growth Factor ◽  
Potential Role ◽  
Tissue Growth ◽  
Matrix Proteins ◽  
Cellular Functions ◽  
Different Types ◽  
Oncological Diseases

Modern concepts about the role of connective tissue growth factor in various physiological and pathological processes are described in the review. Connective tissue growth factor regulates a variety of cellular functions, including proliferation, migration, adhesion, differentiation and synthesis of extracellular matrix proteins in cells of different types. This factor is also involved in more complex biological processes of angiogenesis, chondrogenesis, wound healing, fibrosis and oncogenesis. Increased expression of connective tissue growth factor is observed in different cardiovascular and oncological diseases. Potential role of this growth factor in regulation of cellular senescence and aging processes is also discussed.

Genes and Related Proteins Involved in Amelogenesis Imperfecta

2005 ◽  
Vol 84 (12) ◽  
pp. 1117-1126 ◽  
Author(s):  
G. Stephanopoulos ◽  
M.-E. Garefalaki ◽  
K. Lyroudia
Keyword(s):  
Candidate Genes ◽  
Current Knowledge ◽  
Dental Enamel ◽  
Amelogenesis Imperfecta ◽  
Enamel Formation ◽  
Biomineralization Process ◽  
Genes Encoding ◽  
Kallikrein 4 ◽  
Enamel Proteins ◽  
Related Proteins

Dental enamel formation is a remarkable example of a biomineralization process. The exact mechanisms involved in this process remain partly obscure. Some of the genes encoding specific enamel proteins have been indicated as candidate genes for amelogenesis imperfecta. Mutational analyses within studied families have supported this hypothesis. Mutations in the amelogenin gene ( AMELX) cause X-linked amelogenesis imperfecta, while mutations in the enamelin gene ( ENAM) cause autosomal-inherited forms of amelogenesis imperfecta. Recent reports involve kallikrein-4 ( KLK4), MMP-20, and DLX3 genes in the etiologies of some cases. This paper focuses mainly on the candidate genes involved in amelogenesis imperfecta and the proteins derived from them, and reviews current knowledge on their structure, localization within the tissue, and correlation with the various types of this disorder.

Role of amelogenin self-assembly in protein-mediated dental enamel formation

2010 ◽  
pp. 369-374
Author(s):  
Henry C. Margolis ◽  
Felicitas B. Wiedemann-Bidlack ◽  
Barbara Aichmayer ◽  
Peter Fratzl ◽  
Seo-Young Kwak ◽  
...  
Keyword(s):  
Self Assembly ◽  
Dental Enamel ◽  
Enamel Formation

scholarly journals Epigenetic Mechanisms in Hirschsprung Disease

2019 ◽  
Vol 20 (13) ◽  
pp. 3123 ◽  
Author(s):  
Ana Torroglosa ◽  
Leticia Villalba-Benito ◽  
Berta Luzón-Toro ◽  
Raquel María Fernández ◽  
Guillermo Antiñolo ◽  
...  
Keyword(s):  
Gene Expression ◽  
Neural Crest ◽  
Gene Expression Pattern ◽  
Hirschsprung Disease ◽  
Specific Gene ◽  
Epigenetic Mechanisms ◽  
Cellular Events ◽  
Complex Process ◽  
Strict Regulation

Hirschsprung disease (HSCR, OMIM 142623) is due to a failure of enteric precursor cells derived from neural crest (EPCs) to proliferate, migrate, survive or differentiate during Enteric Nervous System (ENS) formation. This is a complex process which requires a strict regulation that results in an ENS specific gene expression pattern. Alterations at this level lead to the onset of neurocristopathies such as HSCR. Gene expression is regulated by different mechanisms, such as DNA modifications (at the epigenetic level), transcriptional mechanisms (transcription factors, silencers, enhancers and repressors), postranscriptional mechanisms (3′UTR and ncRNA) and regulation of translation. All these mechanisms are finally implicated in cell signaling to determine the migration, proliferation, differentiation and survival processes for correct ENS development. In this review, we have performed an overview on the role of epigenetic mechanisms at transcriptional and posttranscriptional levels on these cellular events in neural crest cells (NCCs), ENS development, as well as in HSCR.

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