ABSTRACT
Objective@#To study the effect of p38 mitogen activated protein kinase (p38 MAPK) on the expression of genes related to enamel development in the enamel epithelium and to provide a basis for the study of the molecular mechanism of enamel development.@*Methods@#The p38 MAPK-specific inhibitor SB203580 dissolved in DMSO was added to the culture medium of mouse mandibular molar tooth germs in vitro as experiment group, and mouse mandibular molar tooth germs treated with the same amount of DMSO were used as control group. Western blot was used to detect the protein expression level of phosphorylated p38 (p-p38) in the enamel epithelium. Real-time PCR was used to detect the mRNA expression levels of runt-related transcription factor 2 (Runx2), osteoblast-specific transcription factor (Osx), ameloblast markers odontogenic ameloblast associated protein (ODAM), amelotin (AMTN), matrix metalloproteinase 20 (MMP20) and kallikrein 4 (KLK4) in the enamel epithelium. @*Results @# Western blot results showed that under the action of the inhibitor SB203580, the phosphorylation level of p38 MAPK in mouse enamel epithelium decreased, and the difference was statistically significant (P < 0.05). Real-time PCR results showed that the expression levels of the transcription factors Runx2 and Osx and the ameloblast markers ODAM, AMTN, MMP20, and KLK4 in the SB203580 group were lower than those in the control group, and the difference was statistically significant (P < 0.05).@*Conclusion@#The p38 MAPK signaling pathway can mediate enamel development by regulating the expression of the transcription factors Runx2 and Osx and the ameloblast markers ODAM, AMTN, MMP20 and KLK4 in the mouse enamel epithelium.
ABSTRACT
BACKGROUND: C-terminus of the amelogenin peptide (AMG-CP) is a small molecular endogenous peptide that is highly shown that AMG-CP can regulate the proliferation and differentiation of cementoblasts, bone marrow mesenchymal stem cells and periodontal ligament fibroblasts, but the biological function of AMG-CP on ameloblasts has not been elucidated. O conserved among species. It is involved in important physiological processes during tooth development. Some studies have BJECTIVE: To investigate the effects of different concentrations of AMG-CP on the proliferation of ALC ameloblasts and its underlying mechanisms. METHODS: AMG-CP was successfully synthesized and determinated by liquid chromatography and mass spectrometry. The effects of AMG-CP at 0, 0.5, 1, 2 mg/L on the proliferation of ALC ameloblasts were observed by xCELLigence RTCA cell analysis system in real time. The effect of AMG-CP at 0, 1, 2 mg/L on cell cycle of ALC was detected by flow cytometry. Real-time PCR was used to detect the expression of cyclin D1, CDK4, MCM2, MCM5 mRNA in ALC cells treated with AMG-CP at 0, 1, 2 mg/L. Western blot was carried out to evaluate the effect of AGM-CP at 0, 1 mg/L on MAPK-ERK1/2 pathway by detecting the expression of phosphorylated ERK1/2 and total ERK1/2 in ALC cells. Pathway blockade assay was performed by using ERK1/2 blocker U0126 to pretreat ALC cells. Then cell proliferation ability as well as phosphorylated ERK1/2 expression was analyzed by xCELLigence RTCA cell analysis system and western blot. RESULTS AND CONCLUSION: Compared with the control group, AMG-CP promoted the proliferation of ALC cells, and decreased the population doubling time in a dose-depending manner. Flow cytometry detected the acceleration of cell cycle after treatment with AMG-CP. The results of Real-time PCR showed that AMG-CP upregulated cell cycle-related genes (cyclin D1, CDK4, MCM2, MCM5) expression. Western blot results showed that AMG-CP could upregulate the expression of phosphorylated ERK1/2 and activate MAPK-ERK1/2 signaling pathway in ALC cells. After U0126 was used to inhibit the MAPK-ERK1/2 pathway, the ability of AMG-CP promoting ALC proliferation was inhibited. These results suggest that AMG-CP has a potential to activate MAPK-ERK1/2 pathway, accelerate the process of cell cycle, and then promote the proliferation of ALC cells, all of which indicate that AMG-CP has the potential to promote the proliferation of ameloblasts.
ABSTRACT
microRNAs (miRNAs) are endogenous short, noncoding RNAs that can negatively regulate gene expression post-transcriptionally. miRNAs are involved in multiple developmental events in various tissues and organs, including dental enamel development. Any disruption during enamel development may result in inherited enamel malformations. This article reviews the expression and function of miRNAs in enamel development.
Subject(s)
Dental Enamel , Gene Expression , MicroRNAsABSTRACT
ABSTRACT. Introduction: ameloblasts are cells responsible for the production and mineralization of the organic matrix of enamel through several stages: pre-secretory, secretory, transition, and maturation. The organic matrix components are produced in the secretory phase. In the maturation phase, the organic component is removed and the mineralization process starts. This process requires the involvement of matrix metalloproteinase 20 (MMP-20), also called enamelysin. Several studies have shown the presence of MMP-20 in tooth development and its relationship to alterations in enamel formation. The objective was: to classify the different studies and laboratory techniques used to demonstrate the involvement of enamelysin in tooth development and its relation to pathologies during enamel formation. Methods: a systematic review was conducted with the following bibliographic databases: PubMed, Science-Direct, Hinari, and SciELO, in order to classify the different studies related to the involvement of MMP-20 in tooth development and the methods to detect its expression, between the years of 2009 and 2014. Results and conclusions: 11 in vitro models show that MMP-20 has specific cleavage sites for enamel matrix proteins. This process is altered by chemical composition, ions, and the presence of hydroxyapatite. Enamel morphology is altered in the knockout models. In human studies, MMP-20 has been associated with increased susceptibility to dental caries, enamel thickness, and dental agenesis.
RESUMEN. Introducción: el ameloblasto es la célula encargada de la producción y mineralización de la matriz orgánica del esmalte. Atraviesa varias etapas: la fase pre-secretora, secretora, de transición y maduración. En la fase secretora se producen los componentes de la matriz orgánica. En la fase de maduración se elimina el componente orgánico y se inicia el proceso de mineralización. Este proceso requiere de la participación de la metaloproteinasa de matriz 20 (MMP-20) o también llamada enamelisina. Diversos estudios demuestran la presencia de MMP-20 en el desarrollo dentario y su relación con alteraciones en la formación del esmalte. El objeto fue clasificar los diferentes estudios y técnicas de laboratorio empleadas que demuestren la participación de enamelisina en el desarrollo dentario y su relación con patologías en la formación del esmalte. Métodos: se realizó una revisión sistemática de la literatura con las siguientes bases bibliográficas: PubMed, Science-Direct, Hinari y SciELO, con el fin de clasificar los diferentes estudios relacionados con la participación de MMP-20 en el desarrollo dental y los métodos utilizados para detectar su expresión, entre los años de 2009 a 2014. Resultados y conclusiones: los modelos in vitro evidencian que MMP-20 tiene sitios específicos de escisión para las proteínas de matriz de esmalte. Este proceso se ve alterado por la composición química, iones, y la presencia de hidroxiapatita. En los modelos knockout la morfología del esmalte está alterada. En los estudios en humanos, se ha relacionado la MMP-20 con una mayor susceptibilidad de caries dental, el grosor completo de esmalte y agenesias dentales.
Subject(s)
Dental Restoration, Permanent , Resins, Synthetic , Dental MaterialsABSTRACT
ABSTRACT. Introduction: ameloblasts are cells responsible for the production and mineralization of the organic matrix of enamel through several stages: pre-secretory, secretory, transition, and maturation. The organic matrix components are produced in the secretory phase. In the maturation phase, the organic component is removed and the mineralization process starts. This process requires the involvement of matrix metalloproteinase 20 (MMP-20), also called enamelysin. Several studies have shown the presence of MMP-20 in tooth development and its relationship to alterations in enamel formation. The objective was: to classify the different studies and laboratory techniques used to demonstrate the involvement of enamelysin in tooth development and its relation to pathologies during enamel formation. Methods: a systematic review was conducted with the following bibliographic databases: PubMed, Science-Direct, Hinari, and SciELO, in order to classify the different studies related to the involvement of MMP-20 in tooth development and the methods to detect its expression, between the years of 2009 and 2014. Results and conclusions: 11 in vitro models show that MMP-20 has specific cleavage sites for enamel matrix proteins. This process is altered by chemical composition, ions, and the presence of hydroxyapatite. Enamel morphology is altered in the knockout models. In human studies, MMP-20 has been associated with increased susceptibility to dental caries, enamel thickness, and dental agenesis.
RESUMEN. Introducción: el ameloblasto es la célula encargada de la producción y mineralización de la matriz orgánica del esmalte. Atraviesa varias etapas: la fase pre-secretora, secretora, de transición y maduración. En la fase secretora se producen los componentes de la matriz orgánica. En la fase de maduración se elimina el componente orgánico y se inicia el proceso de mineralización. Este proceso requiere de la participación de la metaloproteinasa de matriz 20 (MMP-20) o también llamada enamelisina. Diversos estudios demuestran la presencia de MMP-20 en el desarrollo dentario y su relación con alteraciones en la formación del esmalte. El objeto fue clasificar los diferentes estudios y técnicas de laboratorio empleadas que demuestren la participación de enamelisina en el desarrollo dentario y su relación con patologías en la formación del esmalte. Métodos: se realizó una revisión sistemática de la literatura con las siguientes bases bibliográficas: PubMed, Science-Direct, Hinari y SciELO, con el fin de clasificar los diferentes estudios relacionados con la participación de MMP-20 en el desarrollo dental y los métodos utilizados para detectar su expresión, entre los años de 2009 a 2014. Resultados y conclusiones: los modelos in vitro evidencian que MMP-20 tiene sitios específicos de escisión para las proteínas de matriz de esmalte. Este proceso se ve alterado por la composición química, iones, y la presencia de hidroxiapatita. En los modelos knockout la morfología del esmalte está alterada. En los estudios en humanos, se ha relacionado la MMP-20 con una mayor susceptibilidad de caries dental, el grosor completo de esmalte y agenesias dentales.